Neurology 1 Flashcards

Question

What are the major features of the frontal lobe?

Answer 1

Contain the precentral gyrus from which motor instructions (particularly for fine motor control) that are sent to muscles controlling hands and feet. - Primary motor cortex: contains many of the cells giving origin to the descending motor pathways - it is involved in the initiation of voluntary movements. - Premotor and supplementary motor areas: higher level motor plans and initiation of voluntary movements.

Answer 2

Executive" planning – generating models of the consequences of actions Judgmental roles Emotional modulation Working memory: short-term information (rather than long-term factual data) Control of behavior that depends upon context or setting Prefrontal cortex: generating sophisticated behavioural options that are mindful of consequences

Answer 3

Contains the postcentral gyrus which receives sensation from the rest of the body - Primary somatosensory cortex Maintains representations of the body's and of the head's position in space. Permits complicated spatio-temporal predictions – e.g. catching something when you are moving

Answer 4

Plays important roles in integrating sensory information from various parts of the body Interface between cortex and limbic system – association of affect/emotion with things Contains the primary auditiory cortex Inferotemporal cortex: recognition faces and objects

Answer 5

Contains visual cortices Dorsal stream - Vision for movement (Where is it in relation to us) Ventral stream - Vision for identification (What does it mean to us)

Answer 6

10w – cerebral expansion and commissures. 3m – basic structures established. 5m – CNS myelination begins. Continues to adolescence. 7m – lobed cerebrum. 9m – gyri and sulci.

Answer 7

Alcohol crosses placenta. Fetus doesn’t clear alcohol well so fetal levels of alcohol are higher. - Facial abnormalities - Microcephaly - loss of cells, loss of fibres e.g. callosal agenesis, disturbed migration - Irritability - Motor and intellectual impairment

Answer 8

Opiates – neonatal withdrawal Cocaine – neonatal hypoxia, abortion, withdrawal, decreased cognition Ecstasy - long term effects on hippocampus

Answer 9

Taste and smell - well developed at birth. Hearing - responsive at birth. Excellent discriminators of language sounds. Locate sounds from 3 days. Vision Eyes open and sensitive from 7 months. Vision least well developed at birth.

Answer 10

Moro (startle) reflex - the infant is held in the supine position with the head supported, the head is then suddenly allowed to drop. The infant will abduct and extend the arms, open the hands, and then adduct the arms and flex the elbows. Stepping - hold up feet on a surface Palmar grasp - supports own weight, goes by 3 - 4 months Swimming - goes by 4-6 months Babinski reflex - Neonates fan toes when sole stroked

Answer 11

Significant development post-birth e.g. reaching begins at 5th month Attain objects at 8-9m By 2 years, show adult motor patterns

Answer 12

Cartilage and bone in the skull or face. Also give rise to schwann cells, adrenal medulla, meninges, sensory dorsal root ganglia of spinal cord and V, VII, IX and X.

Answer 13

The neural tube usually closes at the end of embryonic week 4. Failure to close cephalic region - anencephaly Failure to close spinal regions - spina bifida Collectively called neural tube defects.

Answer 14

Environmental factors - folic acid and maternal diabetes Genetic factors - 1 sibling 1%, 2 siblings 2%, parent 4% Irish individuals have a greater risk of neural tube defect due to various genetic polymorphisms which activate folic acid.

Answer 15

Spina bifida occulta - opened posterior vertebral body Meningocele - protrusion of the meninges (dura mater) Myelomeningocele - protrusion and opened spinal cord Lower motor neuron lesion - floppy (spina bifida patients are often incontenent) Upper motor neuron lesion - stiffness

Answer 16

Microcephaly - reduced head circumference, brain size is too small, not enough neurons have been made, normally associated with some sort of intellectual disability Macrocephaly - increased head circumference Compared using a normal distribution

Answer 17

Abnormal migrations of neurons | Gene that tells the neurons to migrate is abnormal. Often associated with learning problems and epilepsy.

Answer 18

CSF circulates through the subarachnoid spaces and through the vesicles CSF cushions the brain and helps circulate metabolites About 120mls Produced as filtrate of blood at choroid plexuses in ventricles Absorbed via arachnoid granulations in superior sagittal sinus.

Answer 19

Lateral ventricles found in the cerebral hemispheres Foramen of Monro connects lateral ventricles to the third ventricle Aqueduct of Sylvius connects third ventricle to the fourth ventricle These areas can get blocked by infection Obstructive hydrocephalus - impaired consciousness and a headache

Answer 20

Accumulation of CSF with increased intracranial pressure Can cause macrocephaly in children Obstructive (non-communicating) e.g. tumour, haemorrhage Non-obstructive (communicating) e.g. increased CSF production Try to treat the underlying cause or put in a shunt

Answer 21

Transmission of light: tear film, cornea, aqueous, lens, vitreous, inner retina Refraction of light: cornea and lens Detection of light: photoreceptors and ganglion cells The afferent pathway: optic nerve, chiasm, optic tracts, thalamus, optic radiations, visual cortex The efferent pathway: brain stem nuclei, cranial nerves, ocular muscles

Answer 22

Conical or four-sided pyramidal cavities Open into the midline of the face Point back into the head

Answer 23

Orbital margin - Frontal, Zygomatic, Maxilla | Walls - Lacrimal, Ethmoid, Sphenoid: body, lesser and greater wings

Answer 24

Optic canal Superior orbital fissure Inferior orbital fissure Nasolacrimal fossa

Answer 25

A traumatic deformity of the orbital floor or medial wall, typically resulting from impact of a blunt object larger than the orbital aperture, or eye socket.

Answer 26

A loss of facial movement due to nerve damage. Facial muscles may appear to droop or become weak. It can happen on one or both sides of the face. Common causes of facial paralysis include: - infection or inflammation of the facial nerve - head trauma - head or neck tumor - stroke

Answer 27

Surface layer contains the Meibomian glands Middle layer is aqueous and contains lacrimal glands, lysozyme, lactoferrin, antibodies Deep layer contains mucin: goblet cells

Answer 28

A chronic inflammatory autoimmune disorder which may be primary or secondarily associated with connective tissue disease. Lymphatic infiltration and fibrosis of exocrine glands, especially lacrimal and salivary glands. Dry mouth and dry eyes

Answer 29

Epithelium - Non-keratinising squamous Stroma - Regular lamellae Endothelium - Pumps fluid out of stroma

Answer 30

Very strong Insertion of eye muscles Holes for optic nerve and neurovascular bundle

Answer 31

A disorder of the eye which results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, astigmatism, and light sensitivity. Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea.

Answer 32

Iris - Pupil and Sphincter and dilator muscles to control pupil reflexes The ciliary body - made up of ciliary epithelium: aqueous and ciliary muscle: accommodation and pars plana The choroid - Highly vascular and highly pigmented

Answer 33

A hole in one of the structures of the eye, such as the iris, retina, choroid, or optic disc.

Answer 34

``` INNER RETINA: Internal limiting membrane Nerve fibre layer Ganglion cell layer Inner plexiform layer Inner nuclear layer Outer plexiform layer Outer nuclear layer Outer limiting membrane OUTER RETINA: Photoreceptors Retinal pigment epithelium ```

Answer 35

``` CENTRAL RETINA Macula (lutea) Fovea (centralis) Cone photoreceptors - Fine visual resolution - Colour vision - Photopic vision PERIPHERAL RETINA Rod photoreceptors - Peripheral visual field - Motion detection - Scotopic vision ```

Answer 36

A disease of the eye where the flow of blood through the central retinal artery is blocked (occluded). There are several different causes of this occlusion; the most common is carotid artery atherosclerosis.

Answer 37

``` Continues to grow Contained within elastic capsule Natural shape is almost spherical Shape controlled by ciliary muscle in the ciliary body via zonules Allows for accommodation Fades with age ```

Answer 38

A procedure to remove the lens of your eye and, in most cases, replace it with an artificial lens. Normally, the lens of your eye is clear. A cataract causes the lens to become cloudy, which eventually affects your vision

Answer 39

Anterior segment contains the anterior chamber (AC), cornea, angle, iris, pupil/lens and aqueous humour which circulates from ciliary body, via pupil, into AC and leaves via the trabecular meshwork in the ‘angle’ Small posterior chamber behind iris Posterior segment contains vitreous humour Supportive but largely redundant from birth

Answer 40

Acute angle-closure glaucoma occurs when the flow of aqueous humour out of the eye is blocked and pressure inside the eye becomes too high very quickly. It is an emergency because if it is not treated quickly, it can lead to permanent loss of vision

Answer 41

Aqueous (humour): Produced by ciliary epithelium in ciliary body Maintains intraocular pressure between 12 and 20 mmHg above atmospheric pressure Circulates around lens Low protein ‘plasma’ High vitamin C (antioxidant) Nourishment for avascular structures Vitreous (humour): Collagen matrix Hyaluronic acid and water

Answer 42

As the vitreous separates or peels off the retina, it may tug on the retina with enough force to create a retinal tear. Left untreated, the liquid vitreous can pass through the tear into the space behind the retina, causing the retina to become detached.

Answer 43

``` Rectus muscles: Horizontal (lateral and medial) Vertical (superior and inferior) Oblique muscles: Superior and inferior Arise from orbital apex Insert anteriorly into sclera Nerve supply CNIII: medial rectus, inferior rectus, superior rectus, inferior oblique CNIV: superior oblique CNVI: lateral rectus ```

Answer 44

Horizontal recti: abduction and adduction Vertical recti: mostly elevation and depression other actions depending on globe position in orbit Obliques: Mostly intorsion and extorsion other actions depending on globe position in orbit

Answer 45

Third cranial nerve disorders can impair ocular motility, pupillary function, or both. Symptoms and signs include diplopia, ptosis, and paresis of eye adduction and of upward and downward gaze. If the pupil is affected, it is dilated, and light reflexes are impaired.

Answer 46

``` Wavelength - UV absorbed Eyelids separated - ptosis Normal tear film - dry eye Transparent cornea - scarring, swelling Clear aqueous - inflammation, blood Normal pupil - too large, too small, incorrect position, occluded Clear lens - cataract Clear vitreous - blood, inflammation Normal inner retina - swelling, blood ```

Answer 47

Refractive error, also known as refraction error, is a problem with focusing light accurately onto the retina due to the shape of the eye. The most common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia.

Answer 48

Photoreceptor outer segments Discs contain rhodopsins which respond to different wavelengths Change in structure of retinal opens Na/K channels Hyperpolarisation of membrane closes Ca channels Reduces glutamate release- bipolar cells respond

Answer 49

A rare acquired inability to discriminate colors by hue. Dyschromatopsia is most often associated with damage to the inferior part of the occipital lobes, in the fusiform gyrus.

Answer 50

Images temporal to midline fall on nasal retina Images nasal to midline fall on temporal retina Optic nerves transmit from each eye but maintain orientation Splits at chiasm: Nasal fibres (temporal field) cross Tracts now have information from opposite field but from each eye

Answer 51

``` Pupillary reflexes to light Light sensitive ganglion cells Optic nerve, chiasm, tract Synapse in midbrain (3rd n) 3rd n to ciliary ganglion (orbit) Fibres to sphincter muscle Light stimulus in one eye therefor causes both pupils to constrict (direct and consensual response) ```

Answer 52

A visual field defect is a loss of part of the usual field of vision, so it does not include severe visual impairment of either one eye or both. The lesion may be anywhere along the optic pathway; retina to occipital cortex.

Answer 53

Horner syndrome is characterized by drooping of the upper eyelid (ptosis) on the affected side, a constricted pupil in the affected eye (miosis) resulting in unequal pupil size (anisocoria), and absent sweating (anhidrosis) on the affected side of the face.

Answer 54

Neurons Differentiated glia: Oligodendrocytes, Microglia, Astrocytes Others - glial stem cells, oligodendrocyte precursors, ependymal cells, etc.

Answer 55

Specialized for intercellular electrical signalling via synapses Dendrites receive inputs (dendritic spines), transmit to cell body (soma) Action potentials propagate along axon from axon hillock Mainly, but not exclusively, formed during brain development

Answer 56

Any area in the nervous system composed of mostly unmyelinated axons, dendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies.

Answer 57

Chemical - majority Electrical – less abundant, enable synchronized electrical activity in brainstem neurons (breathing) and hypothalamus (hormone secretion)

Answer 58

Synaptic plasticity is the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity. Basis of learning & memory Highly relevant to disease – e.g. neuro-developmental disorders & Alzheimer’s

Answer 59

Size Morphology Electrical properties Neurotransmitters

Answer 60

Myelinating cells of the CNS Unique to vertebrates Myelin insulates axon segments, enables rapid nerve conduction Myelin sheath segments interrupted by nodes of Ranvier – saltatory conduction Provide metabolic support for axons

Answer 61

Formed by wrapping of axons by oligodendrocyte processes (membranes) Highly compacted – 70% lipid, 30% protein Myelin specific proteins, e.g. MBP, PLP, etc. involved in compaction, excellent “markers”

Answer 62

Resident immune cells of the CNS “Resting” state, highly ramified, motile processes survey environment (2-3 µm/min) Upon activation (e.g. by ATP), retract processes, become “amoeboid” & motile Proliferate at sites of injury - phagocytic

Answer 63

Immune surveillance Phagocytosis – clearing up debris/microbes Synaptic plasticity – pruning during development, refining of the circuitry

Answer 64

"Star-like cells” Most numerous glial cells in the CNS Highly heterogeneous – not all star-shaped Common “marker” glial fibrillary acidic protein (GFAP)

Answer 65

Fibrous – white matter, contact blood vessels, pia & nodes of Ranvier Protoplasmic – grey matter, contact blood vessels & pia

Answer 66

Developmental – will give rise to radial glia Structural - define brain micro-architecture Envelope synapses – “tripartite synapse” Homeostatic – buffer K+, glutamate, etc. Metabolic support - Glutamate-Glutamine shuttle, lactate shuttle, etc. Disease – gliosis/astrocytosis Neurovascular coupling

Answer 67

``` Radial glia –important for braindevelopment Müller cells (in retina) Bergmann glia (in cerebellum) ```

Answer 68

MND symptoms are due to loss of motor neurons. MND spinal cord shows pathological changes in motor neurons, microglia and astrocytes. Pathological CNS lesions in MS involve neurons, oligodendrocytes and T lymphocytes (demyelinating disease). Acute symptoms of MS reflect dysfunction of neurons.

Answer 69

Abundance of neuronal cell bodies in nuclei Axons gathered into tracts Tracts that cross midline = commissures Grey matter abundant in neural cell bodies & processes – neuropil contains few cell bodies White matter contains abundance of myelinated tracts & commissures

Answer 70

Cell bodies & supporting cells located in ganglia – e.g. dorsal root ganglia (DRGs) Axons bundled into nerves Many PNS axons are enveloped by Schwann cells (myelinating cellsof the PNS – neural crest derived)

Answer 71

Endothelial tight junctions Astrocyte end feet Pericytes Continuous basement membrane, lacks fenestrations Need specific transporters for glucose, water, essential ions etc.

Answer 72

Paired structure in the medulla oblongata of the brainstem, is a circumventricular organ having permeable capillaries and sensory neurons that enable its dual role to detect circulating chemical messengers in the blood and transduce them into neural signals and networks.

Answer 73

Epithelial-like, line ventricles & central canal of spinal cord CSF production, flow & absorption Ciliated – facilitates flow of CSF Allow solute exchange between nervous tissue & CSF

Answer 74

Frond-like projections in ventricles Formed from modified ependymal cells, villi form around network of capillaries → large surface area Main site CSF production by plasma filtration (driven by solute secretion) Gap junctions between cells form blood-CSF barrier

Answer 75

Basic cellular unit of the nervous system Huge range - specialised for different functions All have same basic components: dendrites, cell body/soma, axon, presynaptic terminals. Axon transmits the action potential from the cell body, to axon via axon hillock to the synapse.

Answer 76

Unipolar - one structure extending from the soma Bipolar - one axon and one dendrite extending from the soma Multipolar - one axon and many dendrites; Pseudounipolar - single structure that extends from the soma, which later branches into two distinct structures.

Answer 77

Axonal transmission: Transmission of information from location A to location B Synaptic transmission: Integration/processing of information

Answer 78

Eye movements – uncontrolled, seeing double Speech – slurred Paralysis – partial/complete, any part of body Tremor Co-ordination – lost Weakness – tired Sensory – numbness, prickling, pain

Answer 79

Young adults 20-40 Slightly more women than men Temperate zones Areas with high standards of sanitation

Answer 80

Initial symptoms – slight with remission Episodes become more numerous, frequent and severe and become chronic Difficult to diagnose because: Early symptoms slight – person doesn’t go to doctor Other diseases have similar symptoms No definitive current lab-test – diagnosis based on repeated presentation of symptoms combined with an MRI

Answer 81

The signal used by neurones to transmit information between different spatial locations

Answer 82

Some substances which are electrically charged (+ve or –ve) and cross readily – potassium (K+) and chloride (Cl-) Some cross with difficulty – sodium (Na+) Some not at all – large organic proteins (-ve charge)

Answer 83

Diffusion – the force driving molecules to move to areas of lower concentration Electrostatic pressure - ions (like magnets) move according to charge, like ions repel and unlike attract

Answer 84

More K on the inside than the outside – diffusion wants to push them out, electrostatic pressure wants to pull them in (balanced). More Cl on the outside than the inside - diffusion wants to pull them in, electrostatic pressure wants to keep them out (balanced). Na are drawn towards the inside due to diffusion and the electrostatic forces but they can’t get in because the membrane isn’t very permeable to them. Membrane and pump resists Na+ inward movement - some sodium leaks back in but is expelled by the pump. Anions are restricted to the inside of the cell.

Answer 85

Active process to transport Na+ ions out of neuron & K+ in Three Na+ for every two K+ Require energy supplied by ATP

Answer 86

Neuron fires – a sudden pulse where the negative resting potential is temporarily reversed (becomes briefly positive) Transmits information i.e. the message [digitally/all or none/0 or 1] 1) Depolarization & threshold 2) Reversal of membrane potential 3) Repolarisation to resting potential 4) Refractory period

Answer 87

The membrane potential remains in this resting ‘stable’ state until something disturbs the balance. Membrane permeability changes. Neurotransmitters initiate such changes at the dendrites of neurons. Neurotransmitters activate receptors on dendrites/soma Receptors open ion channels Ions cross plasma membrane, changing the membrane potential The potential changes spread through the cell If the potential changes felt at the axon hillock are positive (+mV), and large enough, an action potential is triggered

Answer 88

Excitatory neurotransmitters depolarise the cell membrane, increases probability of an action potential being elicited. This causes an Excitatory Post Synaptic Potential (EPSP). Inhibitory neurotransmitters hyperpolarise the cell membrane, decreases probability of an action potential being elicited. This causes an Inhibitory Post Synaptic Potential (IPSP).

Answer 89

Spatial summation occurs when multiple presynaptic neurones together release enough neurotransmitter to exceed the threshold of the postsynaptic neuron. Temporal summation occurs when one presynaptic neurone releases neurotransmitter many times over a period of time. The total amount of neurotransmitter released may exceed the threshold value of the postsynaptic neurone. The higher the frequency of the action potential the more quickly the threshold may be exceeded.

Answer 90

EPSPs begin to depolarise cell membrane When the threshold (-60mV) is reached Na+ channels open and polarity reverses to +30 inside Membrane potential reverses with the inside going positive at which point voltage-gated Na+ channels close and K+ channels open which restores resting membrane potential

Answer 91

The voltage changes are caused by the opening or closing of ion channels. In the cell membrane there are channels which are opened by detecting opposite polarity in an adjacent bit of membrane, i.e. voltage gated thus voltage changes control the ion channels which control the voltage changes meaning that the action potential is self-perpetuating.

Answer 92

``` Without myelination, signal loss due to lack of insulation and transmission is slow due to the time needed to activate each channel. Saltatory Conduction (jumping between nodes of Ranvier) means that decremental conduction occurs between nodes (but ‘re-boosted’ each time). Myelin insulates sections of the axon leading to faster and more accurate transmission. ```

Answer 93

Degeneration of myelin and development of scar tissue disrupts and eventually blocks neurotransmission along myelinated axons.

Answer 94

Manufacture – intracellular biochemical processes Storage – vesicles Release – by action potential Interact with post-synaptic receptors – diffusion across the synapse Inactivation – break down or re-uptake

Answer 95

Calcium ion channels open when action potential reaches pre-synaptic terminal Ca++ ions cause vesicles to move to release sites – fuse with the cell membrane – and discharge their contents Transmitter substance diffuses across synaptic cleft Attach to receptor sites on post-synaptic membrane The neurotransmitter would remain active in the synapse if it wasn’t for various mechanisms such as enzyme degradation e.g. acetylcholinesterase breaks down acetylcholine.

Answer 96

``` - Fast neurotransmitters – short lasting effects Acetylcholine (ACh) Glutamate (GLU) Gamma-aminobutyric acid (GABA) - Neuromodulators – can be targeted with drugs Dopamine (DA) Noradrenalin (NA) (norepenephrine) Serotonin (5HT) (5-hydroxytryptamine) ```

Answer 97

Transmitter-gated ion channels on post synaptic membrane are sensitive to specific neurotransmitter substances. Results in depolarization or hyperpolarization depending on channel type: - Depolarization - excitatory - EPSP (excitatory post-synaptic potential) - Hyperpolarization - inhibitory - IPSP (inhibitory postsynaptic potential)

Answer 98

``` Procaine and lignocaine Na+ channels blockers-particularly well Can be absorbed through mucous membranes - ’EMLA cream’ Blocks progress of action potential Used in medicine and dentistry ```

Answer 99

``` Transmitter at the neuromuscular junction, also used widely in brain and spinal cord. Affected by: Cigarettes (nicotine - agonist) Poison arrows (curare - antagonist) Spider toxins (black widow - release) Nerve gas (WW-I – blocks break-down) ```

Answer 100

Transmitter in peripheral (heart) and central nervous systems – diverging architecture in brain Affected by: Antidepressant drugs (Imipramine – blocks re-uptake) Antidepressant drugs (MAO inhibitors – block break-down) Stimulants (Amphetamine – increases release and blocks re-uptake)

Answer 101

Important transmitter in basal ganglia – diverging architecture Affected by: Antipsychotic drugs (Chlorpromazine – receptor blocker) Stimulants (Amphetamine/cocaine – increase release and block re-uptake) Anti-Parkinson drugs (L-DOPA increases manufacture)

Answer 102

Diverging projections in the brain – innervating many structures Affected by: Antidepressant drugs (Prozac – serotonin re-uptake inhibitor – SSRI) Hallucinogens (LSD –5HT receptor agonist) Ecstasy

Answer 103

Main inhibitory transmitter Affected by: Anti-anxiety drugs (benzodiazepines - valium – inhibitory effect at GABA receptors Anticonvulsant drugs (benzodiazepines) Anaesthetics (Barbiturates – potentiate the effect of GABA)

Answer 104

A region of the brain engaged in a particular function uses several neurotransmission systems e.g. basal ganglia. AND Regions of the brain engaged in different functions use the same neurotransmission systems.

Answer 105

GABA agonists - anti-anxiety, anti-convulsant, anaesthetic L-DOPA - Anti-parkinson, causes psychosis at high doses Dopamine blockers - Anti-psychotic, causes Parkinson-symptoms at high doses

Answer 106

``` Plain X rays CT scans Magnetic Resonance Imaging Cerebral Angiography Myelography Nuclear medicine – looking at functional status e.g. cerebral blood flow, receptor binding ```

Answer 107

X-ray source which constantly rotates around a series of detectors. Patient goes through the scanner. Dose of radiation: 1 CT head = 100 chest X rays Limited anatomical detail Requires iodinated contrast media – potential for allergic reaction Better than MRI for demonstrating bone and calcification (e.g. craniopharyngioma) Quicker scan times than MRI Can use a CT to create a 3D reconstruction, can model the bones and the intracranial circulation

Answer 108

If you are scanning the head, it needs to be in the middle of the magnet. Can be very claustrophobic. No ionising radiation. Multiple planes possible Excellent anatomical detail Contrast injection may be required Strong magnetic field – in some patients, MRI is contraindicated (metallic implants) Noisy and claustrophobic Longer scan times than CT MRI can be used to look at the fibre bundles of the brain – visualised by looking at the way water diffuses.

Answer 109

Epidural hematoma - bleeding occurs between the dura mater and the skull Subdural hematoma - bleeding occurs between the inner layer of the dura mater and the arachnoid mater Subarachnoid hemorrhage - bleeding within the subarachnoid space Intracerebral hemorrhage - bleeding within the brain tissue itself

Answer 110

Cerebral contusions are bruises of the brain, usually caused by a direct, strong blow to the head. Cerebral lacerations are tears in brain tissue, caused by a foreign object or pushed-in bone fragment from a skull fracture.

Answer 111

Diffuse Axonal Injury (DAI) is considered one of the most common and detrimental forms of traumatic brain injury (TBI). The resistant inertia that occurs to the brain at the time of injury, preceding and following its sudden acceleration against the solid skull, causes shearing of the axonal tracts of the white matter.

Answer 112

A mental process resulting from the immediate external stimulation from a sense organ Sight, sound, taste, touch, hearing

Answer 113

The ability to become aware of something or understand something following sensory stimulation Tactile, olfactory, gustatory, visual, auditory

Answer 114

``` We all have a very unique perceptual set - the psychological factors that determine how you perceive your environment. What we believe influences what we see. Context Culture Expectations Mood and motivation ```

Answer 115

In the visual cortex in the occipital lobe, the nerve impulses are converted into a visual picture. In the primary auditory cortex, the nerve impulses initiated by the vibrations are converted into an understandable auditory input. The limbic system helps us to interrupt the visual and auditory input - do we like or dislike it?

Answer 116

Proximity, common fate, continuity, similarity, closure, common region, symmetry

Answer 117

The instance of a wrong or misinterpreted perception of a sensory experience Can happen in any sensory modality

Answer 118

Experiences involving the apparent perception of something not present 1 in 20 people will at some point in their lifetime will experience a hallucination. Unique hallucinations because each person has a different perceptual set. Not all down to mental illness Causes: Delirium Drugs Acute stress Psychiatric conditions

Answer 119

Bio-psycho-social model Medication Psychology - helping people to understand and reduce the distress they are experiencing Social circumstances

Answer 120

The cerebral hemispheres are paired structures separated from each other by the longitudinal fissure along the midline. Examination of the lateral surface of the brain will reveal the lateral sulcus (the Sylvian fissure). This groove separates the temporal lobe from the parietal lobe. The central sulcus (the Rolandic Sulcus), may be found by looking for two parallel gyri extending from the superior margin of the cerebrum down to the lateral fissure. The sulcus separates these parallel gyri and also demarcates the boundary between the frontal and parietal lobes. The parieto-occipital sulcus separates the occipital lobe from the rest of the brain.

Answer 121

Contains CSF - a pulsatile fluid In systole CSF is forced into the spinal cord In diastole CSF is pushed back into the ventricular system

Answer 122

A white matter sheet that continues ventrally as the internal capsule and dorsally as the centrum semiovale. This sheet of both ascending and descending axons carries most of the neural traffic from and to the cerebral cortex.

Answer 123

Compartments within the subarachnoid space where the pia mater and arachnoid membrane are not in close approximation and cerebrospinal fluid (CSF) forms pools

Answer 124

Located between the cerebellum and the dorsal surface of the medulla oblongata at and above the level of the foramen magnum. CSF produced in the ventricular system drains into the cisterna magna from the fourth ventricle via the median aperture (of Magendie) and the lateral apertures (of Luschka)

Answer 125

A portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes). Folded within itself.

Answer 126

Mental or emotional strain or tension resulting from adverse or demanding circumstances.

Answer 127

Sensory, emotional and subjective experience associated with potential damage of body tissue and bodily threat.

Answer 128

Difficult to separate in practice as the mind/body dichotomy is false: ‘experiences’ and ‘perceptions’ may not be conscious – we may not be completely aware of the emotional stress response.

Answer 129

Positive stress which is beneficial and motivating; typically the experience of striving for a goal which is within reach. Eustress is motivating. “I can do that”

Answer 130

Negative stress which is damaging and harmful. Typically occurs when a challenge (or threat) is not resolved by coping or adaptation. “I don’t think I can manage that”

Answer 131

Type of stressor less important than how it is experienced, ie negative (threat) or positive (challenge), and how bearable.

Answer 132

Good stress increases motivation and leads to increasing attention and interest. Reaches at peak at optimal arousal and interest. When a threat is acute and sudden or if it’s going on for a long time (unresolved), it becomes bad stress and we are less able and less effective - impaired performance because of anxiety. Different kinds of stresses will have different trajectories. Different people will move along at different rate – how quickly people become overwhelmed.

Answer 133

“Any uncomfortable emotional experience accompanied by predictable biochemical, physiological and behavioral changes." “Psychological and physical responses that occurs whenever we must adapt to changing conditions, whether those conditions be real or perceived, positive or negative. Psychological stress occurs when an individual perceives that environmental demands tax or exceed his or her adaptive capacity”

Answer 134

Short-lived response to a novel situation experienced by the body as a danger (usually without conscious processing). Healthy & adaptive. e.g. noise, short-term danger, brief illness, brief physiological challenge

Answer 135

Arises from repeated or continued exposure to threatening or dangerous situations, especially those that cannot be controlled.

Answer 136

Physical illness, disability & pain Physical or sexual abuse Poverty including poor housing, hunger, cold or damp, debt Unemployment Bullying or discrimination – social exclusion Caregiving

Answer 137

Alarm - Threat or stressor identified or realised; body's response is state of alarm Adaptation – stress goes on for a while and body engages defensive countermeasures Exhaustion - body runs out of defences, resources depleted (can lead to illness as a result)

Answer 138

``` Biochemical Physiological Behavioural Cognitive Emotional ```

Answer 139

Stress responses are primarily mediated via the autonomic nervous system (sympathetic-adrenal-medullary (SAM) system) & the hypothalamo-pituitary (HPA) axis. These responses lead to changes that influence future responses to stress, also reflecting brain plasticity – connections alter over time. We can develop responses specific to us. Influenced very early in life (parental care).

Answer 140

Hypothalamus activates the adrenal medulla Adrenal medulla (controlled by the ANS) releases adrenaline and noradrenaline into the bloodstream Body prepares for fight or flight Adrenaline and noradrenaline reinforces the pattern of sympathetic activation e.g. increased heart rate and blood pressure Energy to the muscles

Answer 141

Higher brain centres activate hypothalamus Hypothalamus releases corticotrophin (CSF) Pituitary gland releases adrenocorticotrophic (ACTH) Adrenal cortex releases corticosteroids Corticosteroids cause changes - liver releases energy and the immune system is suppressed.

Answer 142

Glucocorticoids (cortisol) – main stress hormone Catecholamines (adrenaline & noradrenaline) The so-called ‘fight-or-flight’ chemicals

Answer 143

Inflammation and immune response are important but complex. Acute stress: immune suppression Chronic stress: partial immune suppression + low-grade chronic inflammatory response Potential effects on gene expression

Answer 144

Breathing more rapid to increase oxygen Blood flow increases by up to 400% & directed to heart and muscles Increased heart rate & blood pressure Muscles tense Glucose released, insulin levels fall: boost energy to muscles Red blood cells discharged from the spleen Mouth becomes dry (saliva and mucus dry up) Sweating White blood cell redistributed where injury may occur i.e. bone marrow, skin, lymph nodes; less available elsewhere

Answer 145

``` Headache Chest pain Stomach ache Musculoskeletal pain Low energy Loss of libido More prone to colds & infections (immunosuppression) Cold hands & feet Clenched jaw & grinding teeth ```

Answer 146

``` Easily startled & hypervigilant Change in appetite – both directions Weight gain (obesity) or weight loss Procrastinating and avoiding responsibilities Increased use of alcohol, drugs & smoking Nail biting, fidgeting and pacing Sleep disturbances especially insomnia Withdrawal ```

Answer 147

``` Constant worrying Racing thoughts Forgetfulness and disorganisation Inability to focus Poor judgement Being pessimistic or seeing only the negative side ‘what if’ Learning ```

Answer 148

``` Depression & sadness Tearfulness Mood swings Irritability Restlessness Aggression Low self-esteem and worthlessness Boredom & apathy Feeling overwhelmed Rumination, anticipation & avoidance – triggering memories of previous experiences ```

Answer 149

Different parts of the brain mediate responses to different types of stressor (but amygdala and hippocampus are key). Context, appraisal, vulnerability and learning (past experience) may modify perception of threat and hence the stress response. For example, people who experience adversity in early life are more sensitive to stress later on. Stress mechanisms alter affect (mood, anxiety levels). This is likely to mediate the effects of stress on other bodily systems.

Answer 150

Allostasis refers to how multiple & complex systems adapt collectively (e.g. via ANS and HPA axis) in changing environments through dynamic change. Allostatic states are inherently fragile and decompensation can happen quickly (positive feedback loops).

Answer 151

Allostatic load refers to cumulative exposure to stressors (and cost to the body of allostasis), which if unrelieved leads to systems ‘wearing out’. The body’s continued attempts to restore balance take a long-term toll on physiological systems, including plastic changes to the brain itself.

Answer 152

For some people, because of their repeated exposure, they have a particular fine-tuning to stress, so the physiological response will be quicker, more extreme, and longer lasting. The point at which you return to baseline may also be different for people (taking longer to recover).

Answer 153

Stress thought to be related to a host of illnesses, esp of cardiovascular and GI systems, ie those with strong ANS connections. Stress undoubtedly exacerbates physical illnesses and slows recovery. Strong evidence of association between depression and mortality following an MI. But the evidence of causal association between stress and physical illness is still limited.

Answer 154

Cancer: stress linked to survival rather than incidence Cardiovascular disease: high blood pressure, abnormal heart rhythms, MI and stroke Obesity & eating disorders Infertility, recurrent miscarriage & menstrual problems Sexual dysfunction Rheumatoid arthritis Skin & hair problems eg acne, psoriasis, eczema Gastrointestinal problems: inflammatory bowel disease, irritable bowel syndrome. Medically unexplained symptoms (MUS)

Answer 155

``` Vivid flashbacks & nightmares Intrusive thoughts and images Sweating Nausea Trembling Hypervigilance & increased startle response Agoraphobia Insomnia Irritability Impaired concentration ```

Answer 156

``` Shiatsu, T'ai Chi, Yoga Mindfulness Meditation Exercise Sleep hygiene Friends and family Healthy diet Exposure to natural environments Aromatherapy Self help support Cognitive Behavioural Therapy ```

Answer 157

The differential survival and reproduction of individuals due to differences in phenotype.

Answer 158

How successful a organism at reproducing

Answer 159

Competition for mates

Answer 160

More offspring are produced than can possibly survive. Traits vary among individuals with respect to morphology, physiology and behaviour (phenotypic variation). Different traits confer different rates of survival and reproduction (differential fitness in a given environment). Traits can be passed from generation to generation (heritability of fitness).

Answer 161

EP considers the human social brain evolution. It proposes that some human psychiatric mechanisms, defences and traits, are consequences of adaptations to reproductive problems frequently encountered in Pleistocene environments (known as the Environment of Evolutionary Adaptation (EEA)). Proposes theories to account for the widespread existence of substance misuse, borderline states and schizophrenia, bipolar disorder, the dementias and affective disorders as well as other defences, childhood and neurodevelopmental disorders

Answer 162

1. Mechanism – how does this behaviour occur in an individual? 2. Development – how does this behaviour arise in an individual? 3. Evolution – how does this behaviour arise in the species? 4. Adaptive value – why is this behaviour adaptive for the species?

Answer 163

Proximate causation – how? By what mechanism? Answers would lie in biochemistry, anatomy, neuroscience, physiology Ultimate causation – Why was trait selected for?

Answer 164

Mismatch: exposure to evolutionarily mismatched or novel environment e.g culture, alcohol, drugs and diet Life History factors: e.g. reproduction, ageing, menopause, senescence Excessive defence mechanisms Co-evolutionary considerations: losing the arms race against pathogens e.g. HIV, parasites, antibiotic resistance Constraints: imposed by evolutionary history e.g. eyes, backache and brain size

Answer 165

``` Evolution has selected adaptations (defence mechanisms) that help protect against injuries and infections Pain, sickness, illness behaviour Anxiety, depression, OCD Fever, lethargy, fatigue Nausea Itching Sneezing, vomiting, coughing ```

Answer 166

Cognitive limit to the number of people with whom one can maintain stable social relationships

Answer 167

The social brain evolved to deal with the demands of living in hunter-gatherer environments surrounded by kin with a clear delineation between ingroup and outgroup members. New social systems emerged blurring the demarcation between ingroup and outgroups eg towns and cities. Led to a mismatch between the design of the social brain and the novel social environment. Stress caused by this mismatch is what leads to schizophrenia in genetically vulnerable individuals.

Answer 168

Therapy rooted in evolutionary and neuroscience approach to psychological processes. Our brains are designed to function in certain ways, motives, emotions are products of evolution. 3 types of emotion regulation system: - Threat and protection - Drive and excitement - Contentment, soothing and social safeness Compassion focused therapy aimed at facilitating development of soothing and social safeness system

Answer 169

PINNA - cartilaginous structure Formed from pharyngeal arches 1 and 2 (6 Hillocks of His) Forms between 10th and 18th week in utero Directs soundwaves towards ear canal High pitch > Low pitch AUDITORY CANAL - ⅓ cartilage and ⅔ bone Transmits sound from the pinna to the ear drum TYMPANIC MEMBRANE A connective tissue structure, covered with skin on the outside and a mucous membrane on the inside. Pars flaccida - from endoderm and ectoderm Pars tensa - fibrous layer runs through (from mesoderm)

Answer 170

The bones of the middle ear are the auditory ossicles – the malleus, incus and stapes. Sound vibrations cause a movement in the tympanic membrane creating oscillation in the auditory ossicles, transmitting sound. MALLEUS: attaches to the tympanic membrane, via the handle of malleus and then articulates with the incus. INCUS: consists of a body and two limbs, articulates with the malleus and stapes. STAPES: It joins the incus to the oval window of the inner ear.

Answer 171

Acoustic impedance match between air and fluid-filled inner ear Transfer from air to fluid (99.9% loss of energy) Little movement at the tympanic membrane should translate into a big movement to the stapes footplate due to the ratio area and angle Amplification of the airborne sound vibration - 200 fold increase boost in pressure from tympanic membrane to inner ear

Answer 172

VESTIBULE: separated from the middle ear by the oval window, and communicates anteriorly with the cochlea and posterioly with the semi-circular canals. Contains saccule and urtricle. COCHLEA: houses the cochlea duct which twists upon itself around a central portion of bone called the modiolus, producing a cone shape. SCALA VESTIBULI: Located superiorly to the cochlear duct, continuous with the vestibule SCALA TYMPANI: Located inferiorly to the cochlear duct. Terminates at the round window. SEMICIRCULAR CANALS: contain the semi-circular ducts, which are responsible for balance (along with the utricle and saccule). SACCULE: larger of the two, receiving the three semi-circular ducts. UTRICLE: globular in shape and receives the cochlear duct.

Answer 173

To convert mechanical signals from the middle ear into electrical signals, which can transfer information to the auditory pathway in the brain. To maintain balance by detecting position and motion.

Answer 174

Endolymph - fills scala media, high K Perilymph - fills scala tympani and scala vestibuli, like ECF and CSF, Na rich Gradients maintained by Na-K ATPase, NKCC1, CIC-K chlorine channels Channel abnormalities can lead to deafness

Answer 175

A semilunar opening at the apex of the cochlea through which the fluid in the scala vestibuli and the scala tympani communicate so that sound vibrations can pass to the round window.

Answer 176

Displacement of the basilar membrane causes movement of specialised mechanical transducing cells. - Inner hair cells - mechanical transduction (stimulation of the auditory nerve) - Outer hair cells - fine tuning (differentiate specific sounds) As the hair cells are displaced (via stereocilia), the membrane is depolarised due to mechanically gated K channels. Depolarization results in opening of voltage gated Ca channels. Release of neurotransmitters - glutamate (and others) Repolarisation through K efflux (into K poor perilymph)

Answer 177

It runs the entire length of the cochlear. It is narrow at the base, wide at the apex. Stiff at the base, floppy at the apex. High frequencies are detected at the base, low frequencies are detected at the apex.

Answer 178

Sound analysed to encode in formation for neural transmission. Frequency (pitch) - encoded in nerves by location along the basilar membrane

Answer 179

Brainstem is really important for sound localisation - when does sound hit the left ear, when does sound hit the right ear and what is the temporal difference between them, giving indication of the location of the sound.

Answer 180

Medial olive neurons are coincident detectors - they respond only when excitatory signals arrive simultaneously. Anatomical differences in connectivity allow each MSO neuron to be sensitive to sound source from particular location. Sound reach left ear first - action potential begins travelling to medial olive Sound reaches right ear a little later - action potential begins travelling to medial olive

Answer 181

Conductive - damage or a blockage in the outer and/or middle ear. This can result in sound not being conducted adequately through the ear canal to the eardrum, or from the eardrum via the ossicles of the middle ear to the inner ear. Sensorineural - damage or malfunction of the hair cells in the cochlear. Sensorineural hearing loss is the most common type of permanent hearing loss.

Answer 182

Treatment depends on the cause AIMS: - Improve conduction - Improve amplification Can bypass the conductive mechanisms - vibrate the skull, vibrations go straight to the cochlear. Can use a bone-conduction hearing aid, or a surgically implanted, osseointegrated device or a conventional hearing aid.

Answer 183

Typically treated with hearing aids or cochlear implants, which work with a person's remaining sense of hearing to amplify sounds An auditory brainstem implant can stimulate the cochlear nucleus directly.

Answer 184

Parvocellular RGCs: Low-contrast, High linear spatial resolution Koniocellular RGCs: Blue-yellow colour opponency Magnocellular RGCs: High-contrast, Low-resolution, Motion detection, Colour blind

Answer 185

The retina is a thin layer of neural tissue that lines the eye. After the retinal image is encoded by the photoreceptors, neurons within the retina transform the photoreceptor signals into a new representation that is carried by the optic nerve to a variety of locations in the brain.

Answer 186

Functionally (and teleologically) two eyes are better than one for the exploration of the environment and for panoramic defence. A mechanism for the purpose of fusing the images of the two eyes and preventing double vision.

Answer 187

Different attributes of the visual scene are processed simultaneously, in parallel, but in anatomically separate parts of the visual cortex. Everything is back to front and upside down from the eye, this information is corrected in the brain. - Dorsal stream (where pathway) - Ventral stream (what pathway)

Answer 188

Brain uses cues to perceive relative size and position of objects: - Familiar size: Judge distance if know the size of an object - Occlusion: If an object is partially occluding another we presume it is in front - Linear perspective: Parallel lines converge with distance - convergence implies depth - Size perspective: The smaller object will be assumed to be more distant - Distribution of shadows and illumination: Patterns of light and dark can give the impression of depth - Motion parallax: As we move, objects closer than the object we are looking at seem to move quickly and in the direction opposite to our own movement, whereas more distant objects move more slowly and in the same direction as our movement.

Answer 189

Clear vision of an object requires that its image be held steadily on the retina Best vision is possible when the image lies on the fovea Eye movements evolved to aid vision

Answer 190

- Vestibular: hold images steady on retina during brief head rotations/translations - Visual fixation: Holds the image of a stationary object on the fovea by minimizing ocular drifts - Optokinetic: Holds images of the seen world steady on the retina during sustained head rotation - Smooth pursuit: Holds the image of a small moving target on the fovea; or holds the image of a small near target on the retina during linear self- motion - Nystagmus quick phases: Reset the eyes during prolonged rotation and direct gaze towards the oncoming visual scene - Saccades: Bring images of objects of interest onto the fovea - Vergence: Moves the eyes in opposite directions so that images of a single object are placed or held simultaneously on the fovea of each eye

Answer 191

Primary visual cortex (V1) is the gateway for eye movements: Without it, humans cannot make accurate visually guided eye movements Patients with lesions affecting Middle temporal visual area (V5/MT) report akinetopsia (loss of motion vision) and show impaired saccades and pursuit to targets moving in the contralateral visual hemifield.

Answer 192

- Spontaneous saccade: 20/min, visual scan of the environment - Reflexive or non-volitional saccades: short reaction times to new visual, auditory, or tactile cues - Voluntary (intentional or volitional) saccades carry the eyes to a predetermined location corresponding to the position of a visual target or sound Saccades can be voluntarily suppressed to maintain steady foveal fixation.

Answer 193

Generating voluntary saccades Suppression of saccades during steady fixation Subregions of the FEF concerned with vergence and smooth pursuit FEF is involved in triggering of the memory-guided saccade, possibly with a contribution from the parietal lobe (PEF)

Answer 194

Guide saccades during complex tasks - Sequences of movements and responses when the instructional set changes Also contribute to predictive smooth pursuit The SEF seems to play an important role in shifting from a more automatic to volitional behaviour.

Answer 195

Smooth pursuit eye movements allow the eyes to closely follow a moving object.

Answer 196

A reflex, where activation of the vestibular system of the inner ear causes eye movement. This reflex functions to stabilize images on the retinas (when gaze is held steady on a location) during head movement by producing eye movements in the direction opposite to head movement, thus preserving the image on the center of the visual field.

Answer 197

Parietal cortex enhances attention on the moving target Frontal Eye Field contributes to initiation and maintenance of smooth pursuit. Projections descend to the brainstem and subsequently to the flocculus, paraflocculus, and vermis of the cerebellum. The flocculus projects to the ipsilateral medial vestibular nuclus, which, in turn, project to the abducens nucleus. Upward vertical smooth pursuit mediated by the y-group - a small cell group that caps the inferior cerebellar peduncle and downward via the superior vestibular nucleus.

Answer 198

Lateral rectus Medial rectus Superior rectus Inferior rectus You would assume that you would be able to move the eye in any direction, however there are some errors/abnormal movements that need to be corrected by the obliques. Superior oblique Inferior oblique

Answer 199

Fixed to the superior rectus. Inserted onto the upper eye lid Supplied by the oculomotor nerve Facial nerve supply Sympathetic nerve supply Loss of function - Ptosis (drooping or falling of the upper eyelid)

Answer 200

Lateral rectus – pulls the eye laterally (abduction) Medial rectus – pulls the eye medially (adduction) Superior rectus – pulls the eye up and medially and rotates it Inferior rectus – pulls the eye down and medially and rotates it

Answer 201

The superior rectus runs slightly medially, it is not straight. The pull of superior rectus does not pull through the centre of axis of the eye. When it contracts, the eye lifts up but you also get a little bit of rotation of the eye (intorsion). Same is the case for the inferior rectus to give rotation of the eye (extortion).

Answer 202

Inferior rectus gives a degree of extortion but the superior oblique acts to cause intortion, so they cancel each other out enabling the eye to remain upright. Superior rectus gives a degree of intorsion but the inferior oblique causes extorsion, so they cancel each other out enabling the eye to remain upright.

Answer 203

Directly in front Eyes at the same level 2 arms lengths apart – almost at optic infinity (eyes parallel at the horizon into infinity) Test peripheral vision

Answer 204

Both lateral and medial rectus have a ‘isolated’ action – an action which does not rely on any other muscle; so we test these first Sit in front of the patient. Place a finger at eye level about an arms length from their face and move your finger right and left. Do this twice, once whilst observing the left eye and once whilst observing the right eye.

Answer 205

Both superior and inferior rectus can have a ‘isolated’ action, which does not rely on any other muscle, by getting the patient to look 23 degrees to the side Sit in front of the patient. Place a finger at eye level about an arms length from their face and out to the right side move your finger up and down. Repeat this on the left side.

Answer 206

Both inferior and superior oblique cannot ever have a ‘isolated’ action so we position the eye so that superior and inferior RECTI are giving maximal rotation and look for complete correction Sit in front of the patient. Place a finger at eye level about an arms length from their face and out to the left side move your finger up and down. Repeat this on the right side.

Answer 207

The semicircular canals are full of endolymph (lower protein than lymph, doesn’t clot). The endolymph responds to the movement of the head to maintain it at a steady level. This movement distorts the cupula and neuronal impulse generated.

Answer 208

Dizziness occurs when the semi-circular canals send signals to the brain when there is no movement. Can be physiological or pathological.

Answer 209

Inflammation of the ‘hair cells’ often due to viral infection means that the brain sends off a signal when there is no movement, giving the feeling of constant dizziness.

Answer 210

Body tries to twist to compensate - person falls over | Eyes also try to compensate by moving back and forward (nystagmus)

Answer 211

Put ice cold water into the patient's ear canal This will cool the bone and horizontal canal This will consequently cause a convection current to form which will send a signal to the brain. In a normal vestibulo-ocular reflex, the eyes will slowly move towards the direction of the cold water then jump back to normal position. This is an important test for head injury patients.

Answer 212

Cranial nerves (I-XII) - Twelve pairs of nerves attached directly to the brain Spinal nerves - A series of (32) paired nerves attached to the spinal cord, one pair for every vertebra (plus one); Cervical 1-8, thoracic 1-12, lumbar 1-5, sacral 1-5, coccygeal.

Answer 213

Sensory Somatic; general sensations Special sensations Autonomic sensations Motor Somatic and Branchial, for skeletal muscle Autonomic, for smooth muscle and glands

Answer 214

Some say money matters but my brother says big brains matter more. Cranial nerves III, VII, IX and X also have parasympathetic info.

Answer 215

Sense of smell (special sense) Sensory cells synapse with a neuron which sends its axons through the cribriform plate, run along the olfactory tract towards the Entorhinal cortex in the temporal lobe.

Answer 216

Not commonly tested | Test with certain smells that you know the patient will recognise

Answer 217

Olfactory groove meningioma (benign tumour that causes problems because it compresses things) Parkinson’s Epilepsy Trauma - fine fibres which are prone to traumatic damage through sudden deceleration causing a shearing force

Answer 218

Vision (special sense) Runs through the optic canal Complex pathway to the occipital canal Surrounded by the dura, subarachnoid and pia mater for protection.

Answer 219

The lens will invert the image so an image from left hand side will fall on the right hand side of the retina and vice versa. Images from the nasal visual field will cross over to the opposite side of the brain, but images from the temporal visual field remain on the same side of the brain.

Answer 220

``` Remember you are testing pathways! Visual fields - H Visual acuity - eye chart Pupil reflexes - looking at light, accommodation and relative afferent pupillary defect (RAPD) Fundoscopy - shining light in the eye ```

Answer 221

Syphilis: pupil is accommodating (adjusting to close and far) but slow to react Horner’s syndrome – don’t have sympathetic anymore, so parasympathetic innervation takes over Holmes-Adie “tonic” pupil – unequally sized pupils Physiological anisocoria – pupils are unequal but can still respond to the light

Answer 222

If the light signal is not reaching the brain, it will be more dilated than normal (no feedback loop to stop over-dilation).

Answer 223

``` Cranial nerve III, occulomotor; Superior rectus Inferior rectus Medial rectus Inferior oblique Parasympathetic to the pupil and to focus the lens ``` Cranial nerve IV, trochlear; superior oblique Cranial nerve VI, Abducens; lateral rectus

Answer 224

Exits midbrain near Posterior cerebral arteries, passes alongside cavernous sinus, through superior orbital fissure, and branches into two.

Answer 225

Exits midbrain dorsally. Passes round to the front, near Posterior cerebral arteries, passes alongside cavernous sinus, through superior orbital fissure.

Answer 226

Exits between the pons and medulla, passes from the posterior to middle cranial fossa, passes alongside cavernous sinus, through superior orbital fissure.

Answer 227

Damage to CNIII - Eye abducted (lateral rectus) and looks down and rotated (superior oblique). Often will be accompanied with changes in the pupil (larger). Damage to CNIV - Damage -Double vision (rotated) when looking down (the stairs!). One of their eyes is abnormally rotated (superior oblique problems), so the brain corrects this by tilting their head. Damage to CNVI - Eye will not look laterally

Answer 228

Trigeminal nerve Sensation to the face and mouth Muscles of mastication

Answer 229

Exits from pons, passes directly into Meckle’s cave where it divides into three: Opthalmic branch passes through superior orbital fissure Maxillary branch; foramen rotundum Mandibular branch; foramen ovale. Sensory roots- trigeminal sensory nuclei- thalamus- cortex

Answer 230

Ophthalmic division – includes forehead, around the eye, the sclera and runs down the nose Maxillary – from the corner of the eye to the corner of the mouth and up the side of the temple, roof of mouth and all upper teeth Mandibular – floor of mouth, lower jaw, all the muscles attached to the mandible (muscles of mastication – test by clenching teeth)

Answer 231

``` 3 sensory nuclei: - Mesencephalic (jaw jerk) - Main (touch and position from face) - Spinal (pain and temp from face) 1 motor nucleus ```

Answer 232

Sensation to face | Muscles of the jaw - open your mouth, clench your teeth

Answer 233

Cell bodies send signals to the brain when there is no sensation which the brain interprets as pain.

Answer 234

Skeletal muscle; muscles of facial expression and stapedius – always have one of their ends attached to skin Visceral motor (parasympathetic): lacrimal gland and submandibular and sublingual salivary glands, Special sense: taste buds of the anterior two thirds of the tongue.

Answer 235

There is contralateral innervation of the lower face - right side of the brain is supplying the left side of the face and vice versa. Bilateral innervation of the upper face giving forehead sparing – both sides of the brain supply both sides of the forehead (evolutionary advantage for the upper part of the face – if we damage the facial nerve in the cortex, the eyes can still open, as the healthy side can still supply the forehead).

Answer 236

``` Inspect the face at rest for any weakness or asymmetry flattening of the nasolabial folds and drooping of the lower eyelid - smile - raise the eyebrows - puff out the cheeks - shut the eyes tightly - frown ```

Answer 237

Touch the lateral aspect of the tongue with cocktail stick (sugar, salt, or vinegar) then ask the patient to identify the taste.

Answer 238

Damage distal to the stylomastoid foramen will cause a loss of movement. Damage to the nerve within the facial canal will cause loss of movement, loss taste of anterior 2/3 of the tongue and will have a dry mouth (lack of innervation of glands). Damage to the nerve within the internal auditory meatus will have all of the above and a dry lacrimal gland.

Answer 239

Idiopathic Bell's palsy is the commonest lesion of the facial nerve Fractures of the petrous bone Middle ear infections Tumours in the cerebellopontine angle (CPA) (e.g., the vestibular schwannoma) Inflammation of the parotid gland Tumours of the parotid gland

Answer 240

The vestibulocochlear nerve conducts auditory and vestibular-related impulses from the organ of Corti, the semicircular canals, the utricle, and the saccule.

Answer 241

Cochlear: Test hearing by whispering a number into the patient's ears, by using a tuning fork or more complex equipment (Rinne and Weber tests) Vestibular: Difficult to test – stand on one leg with your eyes closed

Answer 242

Basal skull fractures Toxic drug effects e.g. gentamycin Ear infections Vestibular schwannoma (frequently impairs the facial nerve as well)

Answer 243

The glossopharyngeal nerve emerges from the lateral sulcus of the medulla and exits the skull via the jugular foramen, accompanied by the vagus and accessory nerves.

Answer 244

- Somatic sensory: elevate the pharynx using stylopharyngeus muscle - Visceral motor: parotid gland secretion - Somatic sensory: somatic sensation of the skin of the external ear - Visceral sensory: Touch, pain, and temperature in the posterior third of the tongue, the pharynx, and the eustachian tube. Baro and chemoreception in the carotid sinus and carotid body - Special sensory: Taste buds in the posterior third of the tongue

Answer 245

Observe the quality of the patient's voice: - hoarseness is a sign of vocal cord paralysis - nasal voice is a sign of paralysis of the palate Ask the patient to say “ah” and observe the elevation of the palate - bilateral lesions of the vagus nerve the => palate fails to rise - unilateral paralysis => both the palate and the uvula deviate to the normal side Gag reflex Absence of the gag reflex suggests a lesion in the glossopharyngeal or vagus nerves

Answer 246

The vagus nerve emerges from the medulla to exit the skull through the jugular foramen, accompanied by the glossopharyngeal and accessory nerves.

Answer 247

- Somatic motor: swallowing and speech (use of muscles of the pharynx and larynx) - Visceral motor: Autonomic effect on viscera of the thoracic and abdominal cavities - Somatic sensory: Somatic sensation of external ear - Visceral sensory: visceral sensation of pharynx and larynx, the aortic arch and body, and the thoracic and abdominal viscera - Special sensory: taste in posterior pharynx and epiglottis

Answer 248

Unilateral lesions of the nucleus ambigus cause hoarseness, dysphagia, tachycardia, and deviation of the uvula to the side opposite the lesion.

Answer 249

The recurrent laryngeal nerve supplies all the intrinsic muscles of the larynx except the cricothyroid muscle (which is supplied by the superior laryngeal nerve). Compression or damage to the recurrent nerve causes hoarseness secondary to paralysis of the vocal cords.

Answer 250

The accessory nerve supplies the sternocleidomastoid and trapezius muscles.

Answer 251

The cell bodies of the nerve are situated in the ventral horn of the upper five segments of the spinal cord. They send fibres up through the foramen magnum, which then exit the skull with cranial nerves IX and X through the jugular foramen.

Answer 252

Trapezius: Inspect from the back and front and ask the patient to shrug the shoulders. Sternocleidomastoid: Inspect the neck as the patient turns the head against resistance.

Answer 253

The hypoglossal nerve supplies the intrinsic and extrinsic muscles of the tongue.

Answer 254

Its cell bodies are located in the hypoglossal nucleus, which lies between the dorsal motor nucleus of the vagus and the midline of the medulla. It exits the skull through the hypoglossal canal.

Answer 255

Ask the patient to protrude the tongue Atrophy and fibrillations are the hallmarks of the lower motor neuron lesion, which results in tongue deviation to the weakened side.

Answer 256

This syndrome is due to a mass in the Cerebellopontine. This is most commonly a vestibular schwannoma (acoustic neuroma) and less commonly a meningioma. The syndrome has the following signs and symptoms: Progressive sensorineural hearing loss Tinnitus Dizziness Unsteadiness Facial nerve palsy Facial pain and sensory loss and depressed corneal reflex

Answer 257

Vernet's syndrome is due to a lesion in the jugular foramen, most commonly a glomus jugulare tumor. It has the following signs and symptoms: Loss of taste sensation in the posterior third of the tongue (due to involvement of the glossopharyngeal nerve) Paralysis of vocal cords and palate, anesthesia of larynx and pharynx (due to involvement of the vagus nerve) Ipsilateral trapezius and sternocleidomastoid muscle weakness and atrophy (due to involvement of the accessory nerve)

Answer 258

An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.

Answer 259

Nociceptive pain - pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of nociceptors (protective mechanism) Neuropathic pain - pain caused by a lesion or disease of the somatosensory nerve system e.g phantom limb pain, stroke Nociplastic pain - pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for the disease or lesion of the somatosensory system causing the pain.

Answer 260

Allodynia - pain due to a stimulus that does not normally provoke pain Dysesthesia - an unpleasant abnormal sensation, whether spontaneous or evoked e.g. touching a surgery scar Hyperalgesia - increased pain from a stimulus that normally provokes pain e.g area around a burn Hypoalgesia - diminished pain in response to a normally painful stimulus Hypoesthesia - decreased sensitivity to stimulation, excluding the special senses

Answer 261

Acute pain - pain less than 12 weeks Chronic pain - continuous pain lasting more than 12 weeks, pain that persists beyond that tissue healing time. Can be divided into cancer and non-cancer chronic pain.

Answer 262

Nociceptors are sensory neurons that are found in any area of the body that can sense pain either externally or internally. This process (nociception) usually results in the perception of pain. External: skin/cornea/mucosa Internal: viscera/joints/muscles/connective tissue etc The cell bodies of the these neurons reside in either: Dorsal root ganglion (body) Trigeminal

Answer 263

``` Trigeminal neuralgia Glossopharyngeal neuralgia Post Herpetic neuralgia Painful diabetic neuropathy Complex regional pain syndrome ```

Answer 264

Site of injury Activation of nociceptors - start firing Afferent nerve fibre goes very quickly to the dorsal root ganglion In the dorsal horn, it projects into the second neuron into a spinal thalamic tract In the thalamus, it projects into the sensory cortex (awareness of injury)

Answer 265

``` Present on the dorsal root (sensory) Composed of cell bodies of nerve fibres that are sensory (afferent) Pseudo-unipolar neurons First order neurons Can be the source of pain pathology Trigeminal ganglion ```

Answer 266

``` Midline, paired symmetrical structure in the brain Approx 6 X 3 cms long All sensations (except olfactory) relay/pass through ```

Answer 267

Plays a role in perception, motor control, self-awareness and interpersonal experience May also play an important part in addiction This is where the degree of pain (experienced or imagined) Emotional response to the pain

Answer 268

Phantom limb pain - sensory cortex starts remapping the sensory homunculus, different areas then have greater representation than they normally would (e.g. scratching head causes pain in the absence limb)

Answer 269

Biological: age, genger, genetics, physiologic reactions, tissue health Sociological: interpersonal relationships, social support dynamics, socioeconomics Psychological: mental health, emotional health, beliefs and expectations

Answer 270

NSAIDs Paracetamol Opioids Often use a multimodal approach

Answer 271

Tolerance (challenge in acute pain settings) Immunosuppression Deranged HPAxis Opioid Induced Hyperalgesia (OIH) - make you more sensitive and prone to pain No evidence for effective use of opioids in chronic pain

Answer 272

Only a small percentage of patients will benefit from opioid use but difficult to establish the group Not recommended to give more than 120mg Morphine If opioids need to be started encourage patient education, set the time limit, start on a small dose, slowly titrate

Answer 273

Pain associated with direct tumour (tumour infiltration, bone metastases) Pain associated with cancer therapy (chemo, surgery, radiation) Pain unrelated to cancer (RA, OA, headache or herpes zoster)

Answer 274

``` "Biological” symptoms Poor sleep Poor appetite Reduced libido Poor concentration ``` ``` “Cognitive” symptoms Worthlessness (poor self esteem) Guilt Hopelessness Suicidal thoughts ```

Answer 275

Low mood, anhedonia (loss of interest in things that were previously enjoyable), low energy

Answer 276

Our ‘vulnerability’ can be genetic, or a result of early/prenatal experience Early experience sets our neuroendocrinological thermostat - epigenetics

Answer 277

Normally there is cortisol produced and then a negative feedback loop eventually switches off ongoing production of further cortisol. People with depression show an increased level of circulating cortisol in response to stress, they also have enlarged adrenal and pituitary glands and unable to maintain efficient neg feedback. Thought that this is due to reduced glucocorticoid receptor expression in the brain 'glucocorticoid resistance'.

Answer 278

History of childhood maltreatment (with or without current MDD) -> ↑ACTH release in response to stress Affectionate childhood causes increase in GR expression (higher ACTH suppression) Lower social status associated with heavier adrenal glands, increased cortisol in hair and reduced dexamethasone suppression (in monkeys!)

Answer 279

``` Causes the release of steroids which have the following effects... Neurotoxic Cause neuro-vulnerability Affect dendrite formation Reduces neurogenesis Cause changes to the EEG. ``` Particularly affects the frontal lobes and hippocampus.

Answer 280

Medial PFC - Involved in evaluating emotional state and social cognition Less volume loss in depression Dorsolateral PFC - Invovled in working memory and problem solving Large volume loss in depression

Answer 281

Reduced in size in MDD More depressive episodes in the past - decreased size Associates with learning based cognitive deficits Much of the volume loss is irreversible

Answer 282

For most of the 20th Century we thought the adult brain was “fixed” with no new neurons. Grow axons and dendrites, and integrate into existing networks

Answer 283

Restraint and shock stress causes reduced neurogenesis. Particularly when learned helplessness is induced. ‘Social dominance stress’ reduces the number of surviving new cells (same rate). Increased stress, decreases BDNF

Answer 284

All antidepressants boost serotonergic or noradrenergic effects Take about 6 weeks to work – some clinical effect within a week - Antidepressants increase GR expression (regulating HPA activity) - Antidepressants increase neurogenesis - They increase BDNF synthesis by affecting gene expression ∴ improve connectivity and increase number of synapses.

Answer 285

Based on oxygen or glucose take up. Look at functional connectivity Spatially distinct areas of the brain showing similar activity at similar times (temporal pattern). Allows the study of neural networks – considering the whole brain together.

Answer 286

It’s what comes on when there’s nothing to do (“resting state”) Daydreaming, internal ‘flow’ of consciousness.

Answer 287

- Autobiographical details: The self’s place in time and space and projecting to other places in time and space - Self reference: Referring to traits or states and emotional and moral reasoning - Thinking about others: Theory of mind and Social judgements/evaluations

Answer 288

Depressed people find it hard to appropriately switch off their DMN in response to a task. We already knew depressed people excessively ruminate – think about themselves, the past and the future excessively (loops of thought).

Answer 289

Short (8 week) course of daily mindfulness practice reduces activity in the DMN and treats and prevents major depressive disorder. Allows the patient to focus on breathing and be more aware of one's mind.

Answer 290

``` Physical activity Connect with others Learn something new Practice mindfulness Acts of generosity ```

Answer 291

Perceptions can induce emotions. Auditory/olfactory stimuli can also induce certain memories or emotions. Limbic system links perceptual areas into memory and emotion, and translates this into drive-related behaviour. Evolutionary benefit: to avoid danger, pass genes on, establish social standing.

Answer 292

The amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, cingulate gyrus, mamillary bodies.

Answer 293

- Working memory - Long term memory Explicit memory - episodic (day-to-day diary) or semantic (knowledge about stuff) Implicit memory Skills/habits (cerebellum, basal ganglia) - motor routines (driving home) Conditioned reflexes (cerebellum, others) Emotional (amygdala)

Answer 294

To lay down new memories (loss leads to anterograde amnesia). Hypothalamus nuclei are concerned with drive-related behaviours - hunger, thrist, sleep, sex. This is through direct neural connections to the brain and through the release of hormones (neuroendocrine) from the pituitary.

Answer 295

Two tiny nuclei on the underside of the brain. Crucial role in encoding new memories. Very sensitive to alcohol, can be damaged irreversibly.

Answer 296

Receives highly processed information Produces instinctive emotional output Responsible for emotional memory Mediates fear response

Answer 297

Hyperphagia, hypothermia, sleep dysregulation.

Answer 298

Old memories, deja vu/jamais vu, olfactory hallucinations, autonomic disturbance, fear

Answer 299

On the posterior aspect of the midbrain, there is the pairs of superior (visual) and inferior (auditory) colliculi. Together known as the corpora quadrigemina.

Answer 300

Gliomas are tumours of the central nervous system (tumours of the ophthalmic and optic nerves). Schwannomas occur in the other cranial nerves due to the myelination of the schwann cells in the peripheral nervous system.

Answer 301

Abducens nerve comes off the base of the pons. It runs upwards. It has a very long intracranial course. It is susceptible to being stretched if there is a tumour elsewhere.

Answer 302

There is a facial colliculus that lies by the facial nerve nuclei. Lesions can occur here, particularly in patients with MS. Median longitudinal fasciculus can be damaged by MS, breaking communication between the nuclei (internuclear ophthalmoplegia).

Answer 303

Restriction of energy intake relative to requirements leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Intense fear of gaining weight or becoming fat, even though underweight. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight. Subtypes: Restricting and binge-eating/purging

Answer 304

Recurrent episodes of binge eating characterized by both of the following: - Eating in a discrete amount of time (within a 2 hour period) large amounts of food. - Sense of lack of control over eating during an episode. Recurrent inappropriate compensatory behavior in order to prevent weight gain (purging). Binge eating and compensatory behaviors both occur, on average, at least once a week for three months

Answer 305

Recurrent episodes of binge eating: eating, in a discrete period of time more than most people would eat during a similar period and under similar circumstances a sense of lack of control over eating during the episode Episodes associated with three or more of the following: - eating much more rapidly than normal - eating until feeling uncomfortably full - eating large amounts of food when not feeling physically hungry - eating alone because of feeling embarrassed by how much one is eating - feeling disgusted with oneself, depressed or very guilty afterward Marked distress regarding binge eating Bingeing at least once a week for three months (mean) No purging or compensatory behaviours

Answer 306

Presents with many of the symptoms of other eating disorders, but will not meet the full criteria for diagnosis Atypical anorexia nervosa - despite significant weight loss, the individual's weight is within or above the normal range. Bulimia nervosa - of low frequency and/or limited duration Binge-eating disorder - of low frequency and/or limited duration) Purging Disorder – throw up but not to eat a huge amount beforehand Night eating syndrome – semi-autonomous eating in the night

Answer 307

Among females aged 14-40 - anorexia nervosa = 0.5-1% - bulimia nervosa = 1-2% - atypical cases = 3-4% Similar levels in different ethnic groups and socioeconomic groups males have a lower prevalence (c. 10%) The stereotype is not particularly helpful influences help-seeking and referral patterns

Answer 308

Multiple risk factors, but non-specific: genes/temperament, family interaction, social pressures, trauma, etc. Core model: Low self-esteem combined with high perfectionism (likes control but doesn’t feel they have any control) = a need for control Trigger comes along which causes ‘restraint’ – patient finds something that they can control (food) Weight loss reinforces the appreciation for control

Answer 309

Initially, positive reinforcement for weight loss/ control enhances overvaluation of eating, shape and weight as ways of defining oneself Then, terror at losing control - physiological reaction to starvation - body image disturbance - cognitive rigidity - emotional instability (serotonin deprivation) - own body, family and professionals all try to take control and make you eat - enhances the overvaluation even more, and reduces the ability to respond adaptively

Answer 310

``` Severe restriction of food/fluid Electrolyte imbalance Bone deterioration Physical damage e.g., tears to oesophagus; blood in vomit Alcohol/drug intake ```

Answer 311

Muscular weakness - use SUSS test Problems in breathing Deterioration of consciousness Cardiac signs - ectopic beats, tachycardia, bradycardia, low blood pressure Rapid weight loss - not low weight per se (depends what their normal is) Risky behaviours e.g., suicidal intent; risk to others (e.g. driving)

Answer 312

If we use motivational interventions to explore the pros and cons of change or staying ‘ill’, it often doesn't work because this is the only strategy that makes the patient feel safe and the are experiencing impaired emotional and cognitive abilities. Most effective motivator is early behavioural change with reinforcement for doing well.

Answer 313

Bulimia nervosa and binge eating disorder (BED) Cognitive behaviour therapy (CBT) Bulimia - try guided CBT self-help first? Less effective Binge-eating disorder – group CBT Anorexia nervosa Family therapy for adolescent cases CBT, Maudsley AN treatment model (MANTRA), or Specialist Supportive Clinical Management No evidence-based medications

Answer 314

- Structure is key to effective therapies - ‘doing therapies’ have a better record than ‘talking therapies’. Diary keeping and weighing the patient matter. - Risk management - Effectiveness is variable, even with ‘best practice’ - A good therapeutic alliance matters

Answer 315

Voluntary: Running, walking, talking, playing guitar Goal-directed: conscious, explicit, controlled. Habit: unconscious, implicit, automatic Involuntary: eye movements, facial expressions, jaw, tongue, postural muscles throughout trunk, hand and fingers, diaphragm, cardiac, intercostals (around lungs), digestive tract

Answer 316

Motor control governed by lower and upper motor neurons. The lower motor neuron begins (has its cell body) in brainstem or spinal cord and projects to the muscle. The upper motor neurons originate in higher centres and project down to meet the lower motor neurons.

Answer 317

``` The number of muscle fibres varies across individuals, but changes little with either time or training – appears to be genetically determined Muscle size (+ strength) is more about cross sectional area of individual fibres and different proportions of the different types of fibre. ```

Answer 318

Antagonistic arrangement – combined co-ordinated action | Recruitment of muscle fibres – fast/slow twitch, small and large motor units

Answer 319

Motor unit = single alpha motor neuron + all the muscle fibres it innervates – Different motor neurones innervate different numbers of muscle fibres – fewer fibres means greater movement resolution - those innervating finger tips and tongue Activation of an alpha motor neuron depolarises and causes contraction of all fibres in that unit (all or none) Muscle fibres innervated by each unit are the same type of fibre and often distributed through the muscle to provide evenly distributed force (and may help reduce effect of damage)

Answer 320

All the lower motor neurons that innervate single muscle. The motor pool contains both the alpha and gamma motor neurons. Motor pools are often arranged in a rod like shape within the ventral horn of the spinal column

Answer 321

Alpha Motor Neurons originate in the Spinal Cord More distal muscles have their muscle fibres more laterally More proximal muscles have their muscle fibres more medially

Answer 322

Muscles can be contracted or relaxed to provide movement, but a good control system (the CNS) needs to know two things: - how much tension is on the muscle (sensed by Golgi tendon organs) - what is the length (stretch) of the muscle (sensed by muscles spindles)

Answer 323

The GTO is within the tendon (where the muscle joins to bone). Mostly, it is just sending ascending sensory information to the brain via the spinal cord about how much force there is in the muscle. Under conditions of extreme tension, it is possible that GTOs act to inhibit muscle fibres (via a circuit in the spinal cord) to prevent damage.

Answer 324

AKA Muscle sensory receptors Muscle spindles sense the length of muscles, i.e. the amount of stretch. Embedded within most muscles Composed of intrafusal fibers Detect stretch regardless of the current muscle length Sensory fibres are coiled around the intrafusal fibers Intrafusal fibers are innervated separately, by gamma motor neurons They keep the intrafusal fibers set at a length that optimizes muscle stretch detection

Answer 325

Average number of muscle fibres in a motor unit varies according to two functional requirements for that muscle: - Level of control - Strength Typically a range of motor units in a muscle, some with few, some with many fibres. SIZE PRINCIPLE Units are recruited in order of size (smallest first) Fine control typically required at lower forces

Answer 326

Motor command originates in motor cortex (M1) pyramidal cells (upper motor neurons) Cell body located in grey matter of cortex Pyramidal cell axon can project directly to spinal cord and onto lower motor neurons This descending projection also known as pyramidal tract Most cortical projections innervate contralateral motor units

Answer 327

Both contain a direct corticospinal route Both contain an indirect route via brainstem nuclei Dorsolateral Tracts - Route is via the red nucleus - Innervate contralateral side of one segment of spinal cord - Sometimes project directly to alpha motor neuron - Project to distal muscles, e.g. fingers Ventromedial Tracts - Route is via tectum, vestibular nuclei, reticular formation & cranial nerve nuclei - Diffuse innervation projecting to both sides and multiple segments of spinal cord - Project to proximal muscles of trunk and limbs

Answer 328

Basal Ganglia as a centralised action selector – the Vertebrate Solution to the Selection Problem, it turn inhibition OFF for the channel you want to allow through to the motor system. - Receives excitatory input from many areas of cortex (Glutamate) - Output goes back to cortex via the thalamus - Output is mainly inhibitory (GABA) - Complex internal connectivity involving 5 principle nuclei: Substantia Nigra (pars compacta & pars reticulata) Caudate & Putamen (together=striatum) Globus Pallidus (internal and external segments) Subthalamic Nucleus

Answer 329

When damaged, movements become jerky, erratic and poorly co-ordinated Voluntary movement loses fluidity and appears mechanical and robot-like Intention tremor (not like the PD resting tremor) Dysarthria – disruption of fine control of speech, slurring Some people born without one (cerebellar agenesis) and show little impairment (this is debatable)

Answer 330

It knows what the current motor command is It knows about actual body position and movement It projects back to motor cortex Computes motor error and adjusts cortical motor commands accordingly. BUT ALSO Not just motor control, but motor learning too, in collaboration with basal ganglia and cortical circuits. Also involved in a wide variety of non-motor tasks

Answer 331

Cortical - Mostly from motor cortex (copies of motor commands). Also somatosensory and visual areas of parietal cortex Spinal - Proprioceptive information about limb position and movement (muscle spindles, other mechanoreceptors) Vestibular - Rotational and acceleratory head movement (semicircular canals / otoliths in inner ear)

Answer 332

Association fibres Within one cerebral hemisphere Can be short or long (e.g. superior longitudinal fasciculus) Commissural fibres From one side of the brain to the other Largest set of commissural fibres pass through the corpus callosum Projection fibres From top to bottom or bottom to top E.g. internal capsule

Answer 333

E.g. right/left handed Right frontal lobe is larger than the left Left parietal lobe is larger than the right

Answer 334

Parasympathetic – cranial and sacral outflow The cranial nerves run through the brain (cranial outflow) Parasympathetic nerves hitch a ride on the cranial nerves (predominant transport is through the vagus nerve), apart from the sacral outflow. Sacral outflow - colon and sexual function Sympathetic – majority come from the thoraco-lumbar spine Line of ganglia in the sympathetic chain with postganglionic fibres running to their targets with some plexi present (secondary synapses/ganglia) Also involved with adrenal gland amplification.

Answer 335

Sympathetic - increased heart rate and force of contraction, constriction of blood vessels, bronchodilation, decreased gut motility, sphincter contraction and decreased secretions. Parasympathetics - decreased heart rate and force of contraction, vasodilation, bronchoconstriction, increased gut motility, sphincter relaxation and increased secretions.

Answer 336

Symp: Ach and Ach nicotinic receptor in the sympathetic chain, in postganglionic, the neurotransmitter is noradrenaline Para: Ach and Ach nicotinic receptors, the receptor at the end organ is a Ach muscarinic receptor

Answer 337

The autonomic nervous system has two main receptors types: the cholinergic receptors and the adrenergic receptors. The adrenergic receptors are those that are acted upon adrenaline and noradrenaline. Alpha1 and alpha2: mostly involved in the stimulation of effector cells and constriction of blood vessels. Beta 1, 2, 3: mostly involved in the relaxation of effector cells and dilatation of blood vessels

Answer 338

Majority of the receptors (baroreceptors and chemoreceptors) which control the circulatory system are found at the bifurcation of the carotid artery. The chemical balance of the blood and the pressure is monitored and messages are sent to the brain stem nuclei to maintain homeostasis. It is though that most info goes through CNIX. The carotid baro-receptor reflex pathway – once the signal is integrated, info through the vagus nerve will cause constriction or dilatation depending on the pressure detected.

Answer 339

Acute: Pan-dysautonomia with neurological features Chronic: Pure autonomic failure, multiple system atrophy (Shy-Drager syndrome), Autonomic failure with Parkinson’s disease

Answer 340

Hereditary Metabolic diseases – diabetes mellitus, chronic renal failure, chronic liver disease, alcohol induced Inflammatory – Gullian-Barre syndrome Infections – tetanus (bacterial), Chagas’ disease (parasitic), HIV (viral) Neoplasia – brain tumours particularly of the third ventricle or posterior fossa Cardiovascular disorders- Postural hypotension, Supine hypertension, Lability of blood pressure Sexual disorders – erectile dysfunction Alimentary disorders - Gastric stasis, Constipation, Dumping syndromes, Diarrhoea Disorders of the eye

Answer 341

CVS is the easiest to measure – heart rate and blood pressure Head-Up Tilt Test – passive stress (strapped to a table), Patients with disorders will not be able to maintain BP as they are upright but no change in heart rate Baro-reflex testing – phenylephrine test: measure R-R interval after IV pressor agent As you artificially increase blood pressure, the body should initiate a slowing of the heart rate. Degree of autonomic neuropathy – insensitive reflex

Answer 342

Ganglion = a ‘junction box’ - a group of neuron cell bodies in the peripheral nervous system Preganglionic neuron – most are myelinated (fast) Postganglionic neuron – usually unmyelinated (slow) Can be ACh or Noradrenaline

Answer 343

``` Two subgroups: ROSTRAL (upper) - Striatum: Putamen and Caudate nucleus - Globus pallidus: Internal segment (Gpi) and External segment (Gpe) CAUDAL (lower) - Subthalamic nucleus - Substantia nigra ```

Answer 344

Caudate nucleus runs along the wall of the lateral ventricles. Putamen is lateral to the caudate nucleus. Substantia nigra is in the mesencephalon. The subthalamic nucleus is rostrolateral to the substantia nigra.

Answer 345

Motor circuit Limbic circuit Oculomotor circuit

Answer 346

Motor disorders - Parkinson's disease, Huntington's disease, Dystonia, Gilles de la Tourette syndrome Psychiatric disorders - OCD, ADHD Secondary damage - Cerebral palsy, Wilson's disease

Answer 347

Parkinson's disease: increased muscle tone and reduced movements due to not enough dopamine Huntington's disease: decreased muscles tone and overshooting movements due to too much dopamine

Answer 348

Dopamine is produced in the substantia nigra but acts where the axons synapse. L-tyrosine, an amino acid, is converted into L-Dopa. L-DOPA to Dopamine by decarboxylation. Dopamine is stored in synaptic vesicles. When it is released, it acts on a post-synaptic dopamine receptors.

Answer 349

Loss of dominergic neurons In the remainder of dominergic neurons – Lewy bodies form You need to lose about 2/3 of your dominergic neurons before symptoms manifest.

Answer 350

Ventricles appear much larger. | Head of the caudate nucleus has died away, giving the ventricles more space.

Answer 351

Brady/Akinesia Problems with doing up buttons, keyboard etc Writing smaller Walking deteriorated: Small steps, dragging one foot etc Tremor At rest May be on one side only Rigidity Pain Problems with turning in bed

Answer 352

More and more cells die The drugs have shorter and shorter effects The longer on treatment, the more likely are the patients to develop side effects, in particular dyskinesias.

Answer 353

Deep brain stimulation: functional lesioning of the subthalamic nucleus leads to dramatic improvement of PD. Patients have a battery to their chest wall, the electrodes are implanted into the brain and the tip is in the subthalamic nucleus.

Answer 354

Clinical features Chorea (abnormal involuntary movement disorder) Dementia/psychiatric illness Personality change Clinical genetics Autosomal dominant Fully penetrant Expansion of CAG (cytosine-adenine-guanine) triplet repeats in the gene coding for the huntingtin protein results in an abnormal protein.

Answer 355

Problem: Too much dopamine Solution: Dopamine receptor blockers = neuroleptics Typically used for psychosis treatment Up and coming: Downregulation of mutant Huntingtin protein – inactivation of genes

Answer 356

``` Ability to work Activities - daily and social Sastifaction and enjoyment from activities Contact with others Relationships with family and friends Self confidence Sleeping patterns Mood Sense of self Pre-occupation with pain Concerns about the future ```

Answer 357

Acute pain - acts as a warning sign, will often have a diagnosis/explanation and cure, time-limited, patient experiences sympathy, can go back to normal Chronic pain - nuisance, diagnosis/explanation is not always possible, treatment is management-based, less understanding from others, wider aspects of life affected.

Answer 358

Limiting time spent on an activity to prevent marked increases in pain and keeping up a regular amount of activity to prevent problems of too much rest. Planning activity rather than just doing things according to how you feel. Taking breaks, breaking activities down into smaller tasks, changing position.

Answer 359

Pacing Planning Prioritsing

Answer 360

Involves thinking about when and how activities are going to be done. Make sure that difficult activities are spread out. Balance is essential with non-essential activities. Taking regular breaks.

Answer 361

Making choices about what is done | Try to balance what needs to be done with what is pleasurable or interesting.

Answer 362

Causes aches, discomfort and tiredness. Causes simple movements to be stiff and slow. Become normal - may be physically tense without being aware of it.

Answer 363

``` Medication Breathing control and relaxation 3Ps - pacing, planning, prioritising Distraction Support from others Counter stimulation Managing unhelpful thoughts Movement and exercise Advice and information Relaxation techniques ```

Answer 364

Senses which have evolved specialized organs; arise in more evolutionary advanced parts of the brain ``` Olfaction Vision Hearing Balance Taste ```

Answer 365

Dermatome – area of skin supplied by a single spinal nerve

Answer 366

Myotome – a volume of muscle supplied by a single spinal nerve

Answer 367

Sympathetic chain communicates with the spinal cord between T1 and L2 (sends a small component of the nerve to the sympathetic chain). Nerve fibre can go up/down/sideways/synapse. It will eventually synapse at an organ.

Answer 368

The pathway for motor control from the brain to the body. | The pathway for sensory information from the body to the brain.

Answer 369

85% cross over to the other side (decussation of the pyramids) at the upper ventral medulla If we have a patient who is paralysed – looked for pathology on the same side in the spinal cord and on the opposite side in the brain.

Answer 370

``` Motor tract Comes from the precentral gyrus Through internal capsule Crura cerebri 85% decussates medulla (Lateral tract) 15% same side (Anterior tract) ```

Answer 371

Lateral corticospinal tract - rapid, skilled, voluntary movement Rubrospinal tract - facilitates flexors, inhibits extensors Vestibulospinal tract - facilitates extensors, inhibitrs flexors Tectospinal tract - truncal reflexes from sight Anterior corticospinal tract - rapid, skilled voluntary movement

Answer 372

``` Lateral corticospinal tract - pyramids Rubrospinal tract - midbrain Vestibulospinal tract - ipsilateral Tectospinal tract - midbrain Anterior corticospinal tract - thoracic cord ```

Answer 373

Lateral corticospinal tract - contralateral motor cortex Rubrospinal tract - red nucleus Vestibulospinal tract - CNVIII Tectospinal tract - superior colliculus Anterior corticospinal tract - motor cortex

Answer 374

Dorsal columns - touch, vibration, conscious muscle/joint sense Anterior spinocerebellar tract - non-conscious muscle/joint sense Posterior spinocerebellar tract - non-conscious muscle/joint Lateral spinothalamic tract - pain and temperature Anterior spinothalamic tract - light touch, pressure Spino-olivary tract - proprioception Spinotectal tract - spinovisual reflex

Answer 375

Dorsal columns - upper medulla Anterior spinocerebellar tract - immediate Posterior spinocerebellar tract - ipsilateral Lateral spinothalamic tract - two segments Anterior spinothalamic tract - several segments Spino-olivary tract - same segment Spinotectal tract - same segment

Answer 376

Dorsal columns - from legs and arms to sensory cortex Anterior spinocerebellar tract - superior cerebellar peduncle Posterior spinocerebellar tract - inferior cerebellar peduncle Lateral spinothalamic tract - thalamus Anterior spinothalamic tract - thalamus Spino-olivary tract - cerebellum Spinotectal tract - superior colliculus

Answer 377

If we cut the lower motor neuron, the muscle will never receive a signal – muscle becomes flacid and paralysed If we cut the upper motor neuron, there will be no signal to the lower muscle neuron, but the LMN will still receive inputs from other areas so it will fire off spontaneously and create tone in the muscles – the muscles become tight and spastic (deformed)

Answer 378

The spinal cord finishes at L1 The corda equina continues through the lumbar vertebra The cell bodies for the sensory neurones are in the dorsal root ganglia Cell bodies have a higher surface area and take up anaesthetic better than axons Epidural anaesthetic gives a greater sensory block than motor block

Answer 379

Can collect the CSF and diagnose lesions of the cranium e.g. MS or meningitis Can measure levels of glucose in blood and glucose in CSF – bacteria can use up the glucose in the CSF (lower levels)

Answer 380

85% are embolic (gas, solid or liquid) - comes from vertebral or internal carotid 10% are haemorrhagic 5% have rarer causes

Answer 381

Common cause of stroke embolus is atrial fibrillation (uncoordinated movement of the muscle) Left auricular appendage has no blood flow – increased likelihood that a clot will form here

Answer 382

Extradural haemorrhage Subdural haemorrhage Subarachnoid haemorrhage Intracerebral haemorrhage

Answer 383

Meningeal vessels are in the Extradural space Bridging veins cross the subdural space The circle of Willis lies in the subarachnoid space There are no vessels deep to the Pia, the Pia forms part of the blood brain barrier

Answer 384

``` Traumatic Fractured skull Bleeding from Middle meningeal artery Lucid period Rapid rise in inter-cranial pressure (ICP) Coning and death if not treated ```

Answer 385

Bleeding from bridging veins Commonest where the patient has a small brain (alcoholics, dementia) Occurs in ‘shaken babies’ Bridging veins bleed, low pressure so soon stops Days/weeks later the haematoma starts to autolyse Massive increase in oncotic and osmotic pressure sucks water into the haematoma Gradual rise in ICP over many weeks

Answer 386

Rupture of the arteries forming the circle of Willis Often because of ‘Berry aneurysms’ Sudden onset severe headache photophobia and reduced consciousness ‘Thunderclap headache’ Rapidly fatal, the commonest source of organs for transplant since seat belts were made compulsory

Answer 387

Embolic stroke - Death of cell bodies in the cortex - ‘Small’ well defined territory of loss of motor and sensory function - No recovery Haemorrahgic stroke - Compression of the internal capsule - No death of cells - Large territory of loss of motor and sensory function - Possibility of complete recovery

Answer 388

Puncturing the femoral artery, insert a catheter, inject iodine-containing contrast. Very invasive but introduces a catheter which can damage (and consequently a stroke). Moving away from these catheter angiograms. Contrast can also be injected into the cubital fossa and an MRI can be used to image the arterial circulation. These can be used to replace invasive imaging.

Answer 389

Brachiocephalic trunk - divides into right common carotid and right subclavian Left common carotid Left subclavian artery <1% also has the left vertebral artery branching off

Answer 390

Right common carotid arises from the brachiocephalic trunk Left common carotid arises from the aortic arch They have no branches They common carotid arteries bifurcate in the neck at approximately C3/C4 (a lot of variation). Common carotid splits into the internal and the external. The internal goes to provide the blood supply for the brain. The external is primarily for the facial tissues and the dura.

Answer 391

Cervical part - in the soft tissues of the neck Petrous part - hits the petrous bone Cavernous part - into the cavernous sinus Supraclinoid (intradural) - through the dura inside the meninges

Answer 392

No narrowings/dilatations/branches Lie anterior and medial to the internal jugular vein Lies posterior and lateral to the ECA at origin Ascends behind and then medial to ECA (but can vary) ICA is always larger than the ECA

Answer 393

Penetrates temporal bone and runs horizontally (anteromedially) in the carotid canal Small branch to inner ear (caroticotympanic artery) Small potential connection with ECA (vidian artery)

Answer 394

Turns superiorly at the foramen lacerum Enters cavernous sinus Pierces dura at the level of the anterior clinoid process Small branches supply dura, cranial nerves 3-6 (can apply pressure here) and posterior pituitary. If it is injured, you can get a carotid cavernous sinus fistula - leak into the cavernous sinus. Can cause venous hypertension.

Answer 395

Ophthalmic artery is usually intradural and passes into the optic canal Superior hypophyseal arteries/trunk supply pituitary gland, stalk, hypothalamus and optic chiasm Posterior communicating artery runs backwards above CNIII to connect with the PCA Anterior choroidal artery supplies the choroid plexus, optic tract, cerebral peduncle, internal capsule and medial temporal lobe At the top it splits into the anterior and middle cerebral arteries

Answer 396

Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels.

Answer 397

``` Larger of the two terminal ICA branches M1: runs laterally to the limen insulae (lateral lenticulostriate branches) M2: runs in the insular cistern M3: emerge onto the brain surface M4: vessels on the brain surface ```

Answer 398

Supply: Lentiform nucleus (putamen and globus pallidus) Caudate nucleus Internal capsule If there is a clot sitting across these blood vessels, what they supply will die off very quickly (anatomically vulnerable to infarction).

Answer 399

Smaller of the two ICA branches A1: runs medially to connect with the contralateral ACA via anterior communicating artery (medial lenticulostriate arteries supply the head of the caudate nucleus and the internal capsule) A2: runs in the interhemispheric fissure to genu of corpus callosum and has two cortical branches A3: cortical branches from callosomarginal and pericallosal arteries

Answer 400

Form the posterior circulation Vertebral arteries arise from the subclavian arteries Enter at the foramina transversarium at C6 Turn laterally at C2 Loop posteriorly on C1 Go through the foramen magnum anterolateral to the medulla

Answer 401

Carotid dissection (rip in the vessel in torsional forces) will often happen at the opening of the carotid canal. We often see dissections in vertebral arteries too (spontaneously on minimal trauma or through major trauma in dislocations of the cervical spine).

Answer 402

Give off the anterior spinal artery which gives off small medullary perforators Gives off posterior inferior cerebellar artery (PICA) which supplies the medulla and inferior cerebellum

Answer 403

The vertebral arteries unite to form a single basilar artery Runs anteriorly to the pons Has multiple perforating arteries to the brain stem Bilateral anterior inferior cerebellar arteries (AICAs): cerebellum, CN7 and 8 Bilateral superior cerebellar arteries (SCAs) Selective clot in the basilar artery can be one of the worst strokes. Often seen in younger age groups or in the elderly in the context of atherosclerosis.

Answer 404

The two posterior cerebral arteries arise from the terminal bifurcation of the basilar artery PCAs partially encircle the midbrain supplying, by a series of small perforators, the thalamus, geniculate bodies, cerebral peduncles and tectum. In addition the medial and lateral posterior choroidal also supply the tectum, thalamus and choroid of the 3rd and lateral ventricles.

Answer 405

``` Infective causes: Bacterial Viral Fungal Parasitic ``` Non-infective causes: Paraneoplastic Drug side effects Autoimmune (e.g. vasculitis, SLE)

Answer 406

Meningitis - inflammation of the meninges (layer between the bone and the brain)

Answer 407

The brain and the CSF should be a sterile space. If you are bacteraemic, infection can reach the meninges through the bloodstream Extracranial infection - colonisation in the nasopharynx, inner ear infection (otitis media), sinusitis Neurosurgical complications - post op, infected shunts, trauma

Answer 408

There should be any white cells or bacteria in the CSF. Once there is bacteria in the CSF, it can multiply very quickly. This causes increased inflammation which breaks down the barrier between the blood and the CSF, meaning that neutrophils and lymphocytes can get in. This can cause brain swelling.

Answer 409

Fever Headache Neck stiffness - ‘meningism’

Answer 410

Medical emergency - 5% mortality (when treated) | 20% permanent effects including skin scarring, amputation, hearing loss, seizures, brain damage.

Answer 411

Immediate advice: Give IM Benzylpenicillin (if possible) and admit the patient to hospital On arrival to hospital: Assess Glasgow Coma Scale (3 to 15) - how sick they are from the neurological point of view, consider need for intubation Blood cultures before giving antibiotics Broad spectrum antibiotics Steroids (IV dexamethasone) - to reduce inflammation/swelling

Answer 412

Start broad to cover likely/possible organisms First-line: Ceftriaxone or cefotaxime (both cross the blood brain barrier and are anti-bacterial) Special considerations: Penicillin allergy (if the patient has penicillin anaphylaxis, you need to avoid ceftriaxone/cefotaxime) Immunocompromised (risk of listeria) - may need to add in amoxicillin at a high dose Recent travel (risk of penicillin resistance)

Answer 413

Eye response - open spontaneously, open to verbal command, open to pain, no eye opening Verbal response - orientated, confused, inappropriate words, incomprehensible words, no verbal response Motor response - obeys commands, localising pain, withdrawal from pain, flexion to pain, extension to pain, no motor response

Answer 414

Definitive investigation to diagnose meningitis Patient is curled up in the foetal position and a large needle is inserted to collect some CSF. In the lab, they perform microscopy, gram stain culture, protein, glucose, viral PCR (and potentially acid-fast bacilli like TB and histology for tumour cells) on the CSF. Would not perform a lumbar puncture if the patient has abnormal clotting (platelets/coagulation), petechial rash which would suggest a bleeding abnormality or raised intracranial pressure.

Answer 415

Gram negative diplococci 5-11% adult carriage 25% in teenagers If it is found in the blood culture, you can get meningococcal septicaemia (non-blanching purpuric rash, necrosis, high mortality).

Answer 416

``` Bacterial: Neisseria meningitidis (gram neg diplococci) Strep. pneumoniae (gram pos diplococci) Listeria spp. (gram pos rod) Group B strep (gram pos cocci) Haemophilus influenzae B (gram neg rod) E.coli (gram neg rod) ``` Viral: Enterovirus Herpes Simplex Virus (HSV) Varicella Zoster Virus (VZV)

Answer 417

Bacterial: Mycobacterium tuberculosis (TB) Syphilis Fungal: Cryptococcal Other: Non-infective, parasitic

Answer 418

Neisseria meningitidis - children, adults, elderly Strep. pneumoniae - children, adults, elderly Listeria spp. - neonates and elderly Haemophilus influenzae B - children E.coli - neonates

Answer 419

``` Subarachnoid hemorrhage - thunderclap headache Migraine Flu and other viral illnesses Sinusitis Brain abscess Malaria ```

Answer 420

Bacterial - students, travel, immunosuppressed Viral - small children, immunosuppressed TB - TB contact, immunosuppressed Cryptococcal - HIV, immunosuppressed

Answer 421

Bacterial - may appear septic, focal neurology, purpuric rash Viral - recent viral illness, less severe TB - weight loss, night sweats, insidious onset Cryptococcal - high opening pressure

Answer 422

``` Cloudy Polymorphs (neutrophils) under the microscope Organisms can be seen on a gram stain High protein Low glucose ```

Answer 423

``` Clear Lymphocytes under the microscope Staining doesn't reveal anything High protein Normal glucose PCR for HSV, VZV, enterovirus ```

Answer 424

``` "Fibrin web" Lymphocytes under the microscope Organisms seen on phenol auramine/Ziehl Neeelson stain High protein Low glucose PCR for M. Tuberculosis ```

Answer 425

``` "Fibrin web" Lymphocytes under the microscope Organisms seen on India ink stain High protein Low glucose ```

Answer 426

Identify ‘close contacts’ - they have a 1/300 risk of developing meningitis (particularly the first 7 days). Antibiotic prophylaxis reduces the risk and prevents onward transmission (Ciprofloxacin or Rifampicin).

Answer 427

Inflammation of the brain

Answer 428

Usually viral Most commonly Herpes Simplex Sometimes Varicella Zoster Others: measles, mumps, rubella, EBV, HIV, Cytomegalovirus - CMV, coxsackie) Other causes Japanese encephalitis virus Tick-borne encephalitis Rabies West Nile Non-infective: autoimmune, paraneoplastic (Ask about travel! Ask friends/family if patient is confused)

Answer 429

``` Hours to days: preceding ‘flu-like’ illness Then: Altered GCS: confusion, drowsiness, coma Fever Seizures Memory loss (+/- meningism) ```

Answer 430

MRI of the head +/- EEG Lumbar puncture after lymphocytic CSF and viral PCR HIV test (acute stages may cause encephalitis)

Answer 431

Mostly supportive - fluids and nutrition, painkillers, physio, neuro rehab to resolve memory loss or muscle weakness 14-21 days of Aciclovir if HSV or VZV

Answer 432

Inoculation through skin with Clostridium tetani spores (found globally in soil) e.g. stepping on a nail, dirty wounds Bacteria produce toxins Tetanolysin (tissue destruction) Tetanospasmin (clinical tetanus) Tetanospasmin can travel retrogradely along axons. It interferes with neurotransmitter release, which increases neuron firing, and causes unopposed muscle contraction and spasm. Incubation around 8 days.

Answer 433

Generalised tetanus Risus sardonicus - grimace Opisthotonos - spasm of the muscles causing backward arching of the head, neck, and spine Localised tetanus E.g. injury in the hand - unopposed flexion of fingers and spasm of the forearm

Answer 434

If patient has had an at-risk injury - vaccinate If symptomatic: Supportive - muscle relaxants, paracetamol/cooling Immunoglobulin to mop up toxins to stop it progressing Metronidazole to clear up any bacteria

Answer 435

Viral infection that kills 35-50 thousand/yr Inoculation through skin with saliva of rabid animal (dogs, cats, foxes etc) e.g. lick, bite, splash Travels retrogradely along nerves relatively slowly Commonly in Africa, South east Asia

Answer 436

Incubation depends on site and size of inoculation. Minimum 2 weeks, maximum years. Paraesthesia at bite site. Reaches CNS: furious or paralytic presentation Furious - hydrophobic, aerophobic, distressed, confused, agitated

Answer 437

Once symptomatic, it is invariably fatal (>99.9%) | The ones who do survive often have lots of neurological damage

Answer 438

Manage with sedatives Prophylaxis is key: Pre-exposure prophylaxis (vaccination) Post-exposure prophylaxis (vaccination and immunoglobulin)

Answer 439

One of the most common symptoms that clinicians evaluate. One of the problems is that diagnoses cannot always be made and the effective treatment depends on a correct diagnosis. Diagnosis often takes a long time - median time to diagnose a cluster headache is 2.6 years and patients will often see at least 3 GPs before diagnosis.

Answer 440

Primary - migraine, cluster, tension type Secondary - meningitis, subarachnoid haemorrhage, giant cell arteritis, idiopathic intracranial hypertension, medication overuse headache Painful cranial neuropathies, other face pains and other headaches e.g.trigeminal neuralgia (face pain)

Answer 441

Consider in patients who are/have: >50 years old History of HIV, cancer, trauma, risk factors for cerebral venous sinus thrombosis Changing personality or cognitive dysfunction Vomiting without any obvious cause

Answer 442

Jaw claudication or visual disturbance - GCA? Severe eye pain - closed angle glaucoma? Postural Sudden onset headache/thunderclap (could indicate a vascular problem) Exercise or valsalva (e.g. coughing, laughing, straining) Focal neurological symptoms (e.g. limb weakness, unusual aura <5min or >1hr)

Answer 443

``` Fever Altered consciousness Neck stiffness Swollen optic discs Other abnormal neurological examination To check for meningitis or encephalitis ```

Answer 444

Thunderclap headache - subarachnoid haemorrhage Seizure and new headache - electrical problems Suspected meningitis or encephalitis Red eye - acute glaucoma Headache and new focal neurology (including papilloedema)

Answer 445

Red flags - risk >1%: Urgent investigation Orange flags - risk 0.1-1%: Monitor and low-threshold investigation Yellow flags - risk 0.01%: Management but further investigation not excluded Background - risk <0.01% The symptoms and signs guide the level of risk

Answer 446

New headache with history of cancer Cluster headache Seizure Significantly altered consciousness, memory, confusion, coordination Papilloedema Other abnormal neuro exam or symptom (evidence = orange)

Answer 447

New headache where the diagnostic pattern did not emerge over 8 weeks. Headache exacerbated by exercise or valsalva Headache associated with vomiting Headache for some time but changed significantly, particularly if there is an increase in frequency New headache if >50 years old Headache that wakes the patient from sleep Confusion

Answer 448

Diagnosis of migraine or tension type headache Weakness or motor loss Memory loss Personality change

Answer 449

A swelling of the optic disc due to increased intracranial pressure.

Answer 450

Types/number - history for each one Time - onset/duration/how long/why now/frequency and pattern Pain - severity/quality/site and spread Associated - nausea, vomiting, photophobia, phonophobia, cranial autonomic features Triggers - any triggers, aggravating, or relieving factors, family history Response - during attack/function/medication useful Between attacks - normal/persisting symptoms Any changes in attacks

Answer 451

``` Fever Altered consciousness Neck stiffness/Kernig's sign Focal neurological signs - fundoscopy Always check blood pressure too ```

Answer 452

Migraine - Episodic migraine with and without aura - Chronic migraine Medication overuse headache Tension type headache (very common and people aren’t worried about it) Other secondary headaches Cluster headache

Answer 453

5 attacks Attacks lasting 4-72 hours Two of the following: unilateral, pulsing, moderate/severe, aggravation by routine physical activity During the headache at least one of either nausea and/or vomiting, photophobia and phonophobia Not attributed to another disorder

Answer 454

Can be flashing lights, a gleam of light, blurred vision, an odor, the feeling of a breeze, numbness, weakness, or difficulty in speaking. Can be in one eye or both eyes. Fortification spectra - zigzag lines

Answer 455

At least 2 attacks Aura consisting at least one of the following: fully reversible visual symptoms including positive features and/or negative features, fully reversible dysphasic speech disturbance At least 2 of the following: homozygous visual symptoms and/or unilateral sensory symptoms, at least one aura symptom which develops gradually over >5mins or different aura symptoms which occur in succession over >5mins Each symptom lasts >5 and <60 mins Headache fulfilling migraine without aura symptoms which follows within 60 mins Not attributed to another disorder

Answer 456

>10 attacks occurring <1 day/month (>12 days/year) Headache lasting from 30mins to 7 days Headache has two of the following characteristics: bilateral, pressing tightening (non-pulsating) quality Mild or moderate intensity Not aggravated by routine physical activity Both of the following: no nausea or vomiting (anorexia may occur), either photophobia or phonophobia Not attributed to another disorder

Answer 457

At least 5 headache attacks Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes if untreated Headache is accompanied by ipsilateral cranial autonomic features and/or a sense of restlessness or agitation Attacks have frequency from 1 every other day to 8 per day Not attributed to another disorder

Answer 458

At least 3 attacks of unilateral facial pain Occurring in one or more distributions of the trigeminal nerve, with no radiation beyond the trigeminal distribution Pain has at least 3 of the following characteristics: reoccuring in paroxysmal attacks from a fraction of a second to 2 minutes, severe intensity, electric shock like feeling like shooting, stabbing, or sharp, precipitated by innocuous stimuli to the affected side of the face No clinically evident neurological deficit Not better attributed to another diagnosis

Answer 459

Make an accurate diagnosis - manage expectations and initiate close follow up Lifestyle modification and trigger management Pharmacological treatments Psychological and behavioural treatments Surgical treatments

Answer 460

Offer combination therapy for acute treatment of migraine with an oral triptan and an NSAID or an oral triptan and paracetamol For monotherapy, consider oral tripan, NSAID, aspirin (900mg), or paracetamol for the acute treatment of migraine Consider an antiemetic in addition to other acute treatment for migraine even in the absence of nausea and vomiting Do not offer ergots or opioids for acute treatment of migraines

Answer 461

Offer topiramate or propranolol A course of up to 10 sessions of acupuncture over 5-8 weeks or gabapentin (up to 1200mg a day) or Amitriptyline more readily used. For people who are already having treatment with preventatives such as amitriptyline and those whose migraine is well controlled, continue the current treatment as required. Advise people with migraine riboflavin (400mg once daily) may be effective Botulinum toxin A is recommended for the prophylaxis of chronic migraine: if patient is not responding to at least 3 prior prophylaxis treatments and whose condition is appropriately managed for medication overuse.

Answer 462

Wrong diagnosis Drug not effective for patient Effective preventative drug but not used for long enough Non-compliance - used wrong, not tolerated, just not taking it Medication overuse which might complicate the diagnosis

Answer 463

``` Medication overuse headache Meningitis Giant cell arteritis Subarachnoid haemorrhage High intracranial pressure ```

Answer 464

Bloods, blood cultures, throat swab, blood for serology and PCR, HIV test, Chest X-ray, CT head scan, CSF.

Answer 465

8-12 per 100,000 per year Thunderclap headache - maximum severity within seconds (usually) Worse ever SAH until proven otherwise Meningeal irritation - may be late or absent Focal symptoms and signs and coma in severe cases

Answer 466

95% sensitive in the first 24 hours - may help in locating source Lumbar puncture - if CT is normal, it must be done, but not before 12 hours to allow for xanthochromia Angiography

Answer 467

Worse on walking Worse coughing, sneezing, straining Postural, worse lying down Nausea, vomiting Papilloedema - may be absent if acute (look at optic discs using an ophthalmoscope) +/- focal signs Visual obscurations - transient losses of vision lasting a few seconds

Answer 468

Unknown cause, would have normal brain scan and lumbar puncture Risk factors: obesity and drugs e.g. tetracycline Normal CT +/- contrast CSF opening pressure high but normal constituents Imaging to exclude secondary cause and cerebral venous sinus thrombosis (particularly in young women)

Answer 469

When a person no longer has any brain stem functions, and has permanently lost the potential for consciousness and the capacity to breathe. When this happens, a ventilator keeps the person's heart beating and oxygen circulating through their bloodstream.

Answer 470

The petrous part of the skull has an apex. The parasympathetic fibres of the 3rd nerve travels along the petrous apex/cavernous sinus/orbital apex. When the nerve is squeezed against the petrous apex, the patient experiences a fixed dilated pupil - suggests brain swelling.

Answer 471

The main venous drainage is through the sagittal sinus which drains from front to back. At the venous confluence, it divides into a transverse sinus. Transverse sinus becomes the sigmoid sinus down through to the beginnings of the internal jugular vein.

Answer 472

There is an increased risk of venous thrombosis, DVT and PE in women using the contraceptive pill. This also includes a risk of sagittal sinus thrombosis.

Answer 473

The 3rd ventricle drains into the 4th ventricle through the aqueduct of Sylvius. The floor of the 4th ventricle is the brainstem in fron and the roof is the cerebellum behind. There are three exit holes (foramina of Magendie - medial and Lushka - lateral) which allow the CSF to exit the ventricular system into the subarachnoid space. The CSF is absorbed through the arachnoid granulations.

Answer 474

A network of neurons located in the brain stem that project anteriorly to the hypothalamus to mediate behavior, as well as both posteriorly to the thalamus and directly to the cortex. Involved in alertness, sleep/wake, REM, non-REM, respiratory centre, cardiovascular drive.