HNN Flashcards

Question

Discuss general anaesthetic agents

Answer 1

* inhaled or IV * IV usually used to get patient to sleep initially, and then gases used to maintain it * GASES * usually lipophilic * absorbed into blood quickly * cross BBB * rapid action * i.e., halothane, isoflurane * IV * faster action than gases * i.e., propofol

Answer 2

* induce sleep or reduce anxiety * act on GABA receptors (action and side effects vary) * i.e., barbituates - pentobarbitone, and benzodiazepines - diazepam

Answer 3

* used in schizophrenia * D2 antagonists * i.e., typical - chlorpromazine, haloperidol, and atypical - clozapine and olanzapine

Answer 4

Falx cerebri Tentorium cerebelli Falx cerebelli Diaphragma sella

Answer 5

Eyes 4 - spontaneously open 3 - open in response to voice/sound 2 - open in response to pain 1 - don’t open Verbal 5 - normal 4 - confused 3 - inappropriate 2 - incoherent sounds 1 - no response Motor 6 - normal movement (responds to commands) 5 - localises pain 4 - normal flexion 3 - abnormal flexion 2 - extension 1 - no movement Remember NT i.e, if eyes are swollen shut, patient intubated, suspected spinal injury etc.

Answer 6

Cervical - lordosis Thoracic - kyphosis Lumbar - lordosis Sacral - kyphosis

Answer 7

* incrrease noradrenaline and serotonin action * 2-4 weeks theraputic onset * e.g. monoamine oxidase inhibitors (phenelzine), tricyclic antidepressants (imipramine), SSRIs (fluoextine) * rapid onest example = ketamine (can become a drug of abuse)

Answer 8

* correct the imbalance of excitation and inhibition * i.e., Na channel blocker, GABA-pentinoids (act on alpha 2 delta subunit of receptor to reduce neuron activity), drugs which increase GABA action, and barbituates

Answer 9

lithium carbonate

Answer 10

* blocks adenosine receptors on serotonergic neurons (adenosine is produced when tired - caffeine can reduce sleep quality/quantity) * increases energy metabolism in the brain * decreases cerebral blood flow * boosts adrenaline and dopamine * withdrawal causes imbalance a sbrain gets used to the effects (symptomatic)

Answer 11

* increased GABA (disinhibition, sedation, and loss of balance) * increased adrenaline (high BP) * decreased L glutamic acid/glutamate (memory disruption) * increased serotonin (sedation and euphoria) * increased dopamine (elevated mood)

Answer 12

prostate gland

Answer 13

* decreased GABA (anxiety, insomnia, and seizures) * increased adrenaline (high BP and tachycardia) * increased glutamate (delerium and seizures) * decreased serotonin (insomnia and mood disorder) * decreased dopamine (dysphoria)

Answer 14

* continued alcohol use offsets GABA and glutamte balance (more GABA function/less glutamate function) * brain adjusts and creates a new normal - downgrades GABA receptors/upgrades glutamate receptors (to try compensate for continued alcohol use) * when alcohol is removed NT levels return to normal * however, due to the change sin receptor sensitivity changes you get less GABA function and increased glutamate function * this causes withdrawal symptoms * the more tolerance built up to alcohol, the greater the withdrawal effects

Answer 15

* act on multiple receptors * cause G protein coupled recpetor changes * can have a therapeutic effect in epilepsy, nausea, and spasticity * THC - causes mood chnage and sedative effects - high conc. of THC can cause psychiatric symptoms with sustained use * cannabidiol - recognised medicinal effects in epilepsy

Answer 16

cocaine - blocks reuptake of dopamine and serotonin heroin - an opiod - floods dopamine by blocking GABA release ecstatsy - reverses reuptake of serotonin, afrenaline and dopamine LSD - acts on5HT2a receptors (serotonin receptors) MDMA - blocks monoamine reuptake amphetamines - releases catecholamines and block monoamine oxidases THESE DRUGS HAVE A RAPID ONSET WITH VARIOUS EFFECTS AND ARE BEST AVOIDED DUE TO THEIR HIGH TOLERANCE, HIGH SCALE EFFECT, AND HIGH ADDICITION RATE

Answer 17

* aka nootropic drugs * improve memory and cognitive performance * e.g. ACE inhibitors (used in Alzheimer’s) and piracetam derivatives * no effect on normal brain

Answer 18

excess dopamine action

Answer 19

lack of dopamine action

Answer 20

lack of ACh action (autoimmune attack occurs when autoantibodies form against the nicotinic acetylcholine postsynaptic receptors (nAChR) at the neuromuscular junction of skeletal muscles)

Answer 21

* lack of serotonin action - lack of noradrenaline action

Answer 22

* lack of GABA action - increased glutamte action

Answer 23

lack of serotonin action

Answer 24

* can’t be seen in a scan * often associated with deep comatose patients * damage to axons caused by the brain being ‘shaken’ by head trauma

Answer 25

mild = 14-15 moderate = 9-13 severe = 3-8

Answer 26

* a lower GCS is associated with a lower GOS - however, this is a les strict relationship now as we can treat head injuries better - minimising secondary insult

Answer 27

age, GCS (motor component tends to eb a good indicator for recovery), pupillary response (present is better for recovery), CT features, hypotension, hypoxia, glycaemia, and anaemia

Answer 28

corticospinal (main motor output), basal ganglia (modulator), and cerebellar (modulator)

Answer 29

* Brodmann area 4 * located in the posterior frontal lobe * works with other regions to plan and execute movement * contains large numbers of betz cells (send axons to the spinal cord)

Answer 30

* Brodmann area 6 * located on the medial surface of the frontal lobe * anterior to primary motor cortex * role in motor planning and initiation of movement based on past motor memory * can measure anticipation/planning of movement using bereitschaft potential * axons sent to premotor and motor cortex

Answer 31

* Brodmann’s area 6 (lateral area) * modulates posture by optimising joint position/posture for a movement * responds to visual and sensory cues * major pathway by which fine movements are controlled by vision * axons sent to motor cortex and corticospinal tract

Answer 32

* assess the context in which movements are made * receives sensory, proprioceptive, and visual inputs and uses them to determine the body’s positon in space (and position of the target) * produces internal models of the movement to be made before involving the premotor and primary motor cortices * works alongisded premotor cortex - together are the highest level of motor control hierarchy * sends axons (alongside premotor cortex) to the primary motor cortex which determines the characterstics of the appropriate movement

Answer 33

* descending fibres from the primary motor cortex, supplementary nmotor cortex, and premotor cortex form the cornoa radiata and converge as they pass through the posterior limb of the internal capsule * descend through the crus cerebri in the anterior midbrain * axons synapse with the brainstem cranial nerve motor nuclei * tracts continue into the brainstem and become visible as two pyramids on the ventral surface of the medulla * 90% decussate in the medulla * axons descend within the lateral corticospinal tract * synapse with anterior horn cells

Answer 34

* Petromastoid * Tympanic * Squamous

Answer 35

* Tensor tympani: Largest, attached to malleus Contracts in response to loud noise to protect cochlea Innervated by mandibular branch of trigeminal nerve (V3) Originates from the first pharyngeal arch. * Stapedius Smaller, attached to stapes, involved in the stapedius reflex Innervated by nerve to stapedius (facial nerve) Originates from the second pharyngeal arch.

Answer 36

Action potentials generated in first-order neurons of the spiral ganglion (cochlea). Impulse travels in the cochlear part of the vestibulocochlear nerve (CN VIII), which travels in the internal acoustic meatus. Reaches the cerebello-pontine junction and synapses onto cochlear nuclei (medulla-pons junction) Continues along olive and trapezoid body of pons to the inferior colliculus of the midbrain. Reaches medial geniculate body of thalamus Travels up to superior temporal gyrus (auditory cortex).

Answer 37

* Vestibulum Vestibulospinal tract: from semicircular canals to vestibular part of vestibulocochlear nerve (CN VIII) Then onto vestibular nuclei (pons) Upwards to primary vestibular sensory areas of parietal lobe. * Vision Control and fixation of gaze (stable frame of reference, no jittery vision) * Proprioception

Answer 38

Detect rotatory acceleration. 3 semicircular canals - Lateral: tipped up 30º from horizontal - Superior: sagittal rotation (front roll) - Posterior: coronal rotation (cartwheel) * Work in pairs, e.g. left and right lateral canals, left superior & right inferior * Each canal has a dilatation at one end - the ampulla. * Ampulla constains crista (sensory organ) * Crista contains hair cells embedded in a gelatinous cupula * Movement of endolymph within canal displaces the cupula * Flow towards the ampulla stimulates lateral canals. * Flow away from the ampulla stimulates superior and posterior canals.

Answer 39

Detect linear acceleration. - Utricle Larger, more sensitive in horizontal plane Output mostly to eye muscles * Saccule Smaller, more sensitive in vertical plane Output mostly to postural muscles Each has a macula containing hair cells Tips of stereocilia embedded in otolithic membrane, which is weighed down by otoliths (calcium carbonate granules) Gravity acts on otoliths, displacing the membrane relative to the hair cells, triggering depolarisation

Answer 40

Vestibular part of vestibulocochlear nerve (CN VIII) Synapse in vestibular nuclei (pons) Outputs * via thalamus to cortex for conscious awareness of position of head in space * to oculomotor, trochlear and abducens nuclei in brainstem for control and fixation of gaze * to cerebellum, accessory nerve nucleus and vestibulospinal tract for control of posture

Answer 41

* Temporal * Zygomatic * Buccal * Cervical * Marginal mandibular

Answer 42

Arterial blood supply: branches of external carotid - Posterior auricular artery Gives off superficial temporal artery. Venous drainage: retromandibular vein Formed by convergence of maxillary and superficial temporal veins.

Answer 43

* Sympathetic Superficial cervical ganglion Inhibits saliva secretion via vasoconstriction * Parasympathetic Glossopharyngeal nerve: synapses at otic ganglion Auriculotemporal nerve (branch of V3): carries parasympathetic fibres from otic ganglion to parotid gland. * Sensory Parotid: auriculotemporal nerve Fascia: great auricular nerve

Answer 44

* Dermatome of ophthalmic nerve: Supraorbital nerve * Dermatome of maxillary nerve: Zygomaticotemporal nerve Zygomaticofacial nerve Infraorbital nerve * Dermatome of mandibular nerve: Auriculotemporal nerve Buccal nerve Mental nerve * Back of head: C2 & C3

Answer 45

* Superior thyroid artery * Ascending pharyngeal artery * Lingual artery * Facial artery * Occipital artery * Posterior auricular artery * Maxillary artery * Superficial temporal artery

Answer 46

* Stylopharyngeus * Salpingopharyngeus * Palatopharyngeus These muscles elevate the pharynx to receive food from the oral cavity

Answer 47

Olfactory nerve (CN I) - cribriform plate Optic nerve (CN II) - optic canal Oculomotor (CN III), trochlear (CN IV), abducens (CN VI) and ophthalmic nerve (V1) - superior orbital fissure Trigeminal nerve (CN V) * Maxillary branch (V2): foramen rotundum * Mandibular branch (V3): foramen ovale (meningeal branch exits through foramen spinosum) * Facial ( CN VII) and vestibulocochlear (CN VIII) nerves: internal acoustic meatus * Glossopharyngeal (CN IX), vagus (CN X), accessory (CN XI): jugular foramen * Hypoglossal nerve (CN XII): hypoglossal canal

Answer 48

Vertebral/Batson venous plexus * In epidural space * Become continuous with segmental veins that exit via intervertebral foramen

Answer 49

* Derived from segmental branches originating from the aorta * At the level of the thoracic spinal cord, intercostal arteries project into the spinal cord as: 2 posterior spinal arteries - derived from posterior inferior cerebellar artery or vertebral arteries 1 anterior spinal artery (Artery of Adamkiewicz) * supplies lower third of spinal cord * usually arises from left posterior intercostal artery

Answer 50

CSF is produced by the choroid plexus (mainly in lateral ventricle, some in 4th ventricle) Fills lateral ventricles then flows to 3rd ventricle via intraventricular foramen of Munro Then flows through aqueduct of Sylvius (midbrain) to 4th ventricle 4th ventricle communicates with subarachnoid space via lateral foramina of Luschka and median aperture of Magendie CSF is resorbed into the venous sytem via arachnoid granulations

Answer 51

* Small perforating arteries arising from the main trunks of the MCA and PCA * Deep white matter and basal ganglia are supplied by lenticulostriate arteries

Answer 52

- Thrombolysis (within 4.5 hours) With tPA (tissue plasminogen activator) * Thrombectomy For blood clots too large to dissolve with tPA Femoral catheter insertion, passed into carotid artery to find clot, deploy stent retriever & remove clot * Hemicraniectomy Allows reduction in ICP after major stroke, reducing fatality

Answer 53

* Inspiration Diaphragm Phrenic nerve (C3-5) * Shoulder abduction Deltoid Axillary nerve (C5) * Elbow flexion Biceps brachii, brachialis Musculocutaneous nerve (C5-6) * Elbow extension Triceps brachii Radial nerve (C7-8) - Wrist extension Extensor carpi radialis longus & brevis Radial nerve (C6,C7) * Finger flexion Flexor digitorum superficialis & profundus Median nerve (C8) * Finger abduction and adduction Interossei Ulnar nerve (C8,T1)

Answer 54

- Thigh adduction Adductor longus and brevis Obturator nerve (L2-3) * Knee extension Quadriceps Femoral nerve (L3-4) * Ankle dorsiflexion Tibialis anterior Deep peroneal nerve (L4,L5) * Great toe extension Extensor hallucis longus Deep peroneal nerve (L5,S1) * Ankle plantarflexion Gastrocnemius, soleus Tibial nerve (S1-2) * Anal contraction Sphincter ani externus Inferior anal nerve (S2-4)

Answer 55

* Due to bony compression/disc protrusions in lumbar/sacral region Presentation * Pain: backs of thighs & legs * Numbness: buttocks, backs of legs (saddle paraesthesia) , soles of feet * Weakness: paralysis of legs & feet * Atrophy: calves * Paralysis: bladder & bowel

Answer 56

* Causes: Penetrating trauma MS Tumour * Presentation Ipsilateral (UMN) weakness (corticospinal) Ipsilateral loss of proprioception (dorsal columns) Contralateral loss of pain & temperature (spinothalamic)

Answer 57

Dorsal horn level Under normal circumstances, inhibitory interneurons are actively blocking ongoing nerve input C fibres block inhibitory interneurons, allowing C fibre input to be transmitted across the synapse from a primary to a secondary afferent If the inhibitory interneuron is stimulated by a collateral branch of an A beta fibre, the other A beta branch will activate the dorsal column/medial lemniscal pathway to block ongoing transmission of C fibre nociception

Answer 58

Engaged under extreme circumstances Conditioned pain modulation - descending modulation, top-down inhibition Stimulation of higher structures in the brain activates the peri-aqueductal grey matter (pons) and medullary raphe nuclei (most endogenous opioids found here) Activates descending nerve fibres going to spinal cord, suppressing pain entering spinal cord Direct inhibition of projection neurons or enkephalin-containing interneurons reduces activity in nociceptive circuits Neurotransmitters involved lower down: 5-HT and noradrenaline

Answer 59

Light hits the retina; signal travels through the optic nerve (CN II) Medial fibres carrying information from the lateral field of vision decussate at the optic chiasm Fibres subserving the light reflex bypass the lateral geniculate body They synapse in the ipsilateral pre-tectal nucleus Then projet to ipsilateral and contralateral Edinger-Westphal nucleus (CN III nucleus) Synapse in ciliary ganglion Parasympathetic fibres of CN III innervate sphincter pupillae Pupillary constriction in both eyes (direct & consensual light response)

Answer 60

Patient is asked to look at a distant object then at an object close to the face Both pupils should constrict and dilate again when distant gaze is resumed Fibres from medial rectus travel along CN III Liaise with mesencephalic nucleus of CN V Go to convergence centre (tectal/pre-tectal region) Then go to Edinger-Westphal nucleus Efferent signal comes out along CN III, synapses at ciliary ganglion Activates sphincter pupillae

Answer 61

Tests the integrity of the pyramidal tract to identify corticospinal lesions Nociceptive afferent signals from S1 dermatome travel in sciatic nerve, reaching the spinal cord Efferent signals exit via ventral horn Toe extensors innervated by deep peroneal nerve Toe flexors innervated by tibial nerve Loss of descending pyramidal control results in the loss of extensor suppression, leading to an upgoing plantar response Toe extension, upgoing plantar: positive Babinski sign

Answer 62

Posterior cord syndrome affects the posterior spinal arteries. Results in an ipsilateral loss of proprioception and vibration sense below the level of the lesion (pain is intact) Causes: B12 deficiency Copper deficiency Syphilis HIV/HTLV1 Extrinsic compression (tumours)

Answer 63

* Suspended sensory loss at the level of the decussating spinothalamic fibres * Weakness may affect arms more than legs Causes: Syrinx (fluid-filled cyst in spinal canal) Slow-growing tumour Hyperextension injury Anterior cord compression by osteophytes, posteriorly by ligamentum flavum

Answer 64

Touching cotton wool to the cornea tests trigeminal nerve function (CN V) in the eye being tested, and facial nerve function (CN VII) in both eyes Signal relayed in ophthalmic branch of trigeminal nerve (V1) synapsing in main sensory nucleus of trigeminal nerve Then, synapses onto the medial longitudinal fasciculus Reaches the main motor nucleus of the facial nerve Facial nerve innervates orbicularis occuli, causing blinking

Answer 65

Deficit (partial or complete) in motor and all sensory modalities Sensory level associated with transverse cord syndrome Causes: Trauma Tumour MS/transverse myelitis

Answer 66

Increases the amount of movement Glutamate neurons project from the thalamus to the cortex (excitatory) Globus pallidus interna and substantia nigra pars reticulata project to the thalamus and release GABA (inhibitory) To initiate a movement, signals are sent from the cortex to the striatum (corticostriatal pathway) Activated striatal neurons inhibit globus pallidus interna and substantia nigra pars reticulata, preventing their inhibition of the thalamus and allowing movement Substantia nigra pars compacta modulates the activity of direct pathway via dopamine release in the striatum, which facilitates the pathway

Answer 67

Reduces amount of movement GABA neurons project from globus pallidus externa to subthalamic nucleus (inhibitory) When indirect pathway is activated by signals from the cerebral cortex, GABA neurons in the striatum are activated These neurons project to globus pallidus externa and inhibit its activity, preventing it from inhibiting the subthalamic nucleus Subthalamic nucleus neurons are activated by projections from the cortex These stimulate neurons in the globus pallidus interna and substantia nigra pars reticulata, which will inhibit the thalamus Substantia nigra pars compacta modulates this pathway via dopaminergic input, which inhibits activity in the indirect pathway, facilitating movement

Answer 68

Neuroepithelial cells in the neural tube give rise to neuroblasts (primitive nerve cells) As the wall of the neural tube thickens, neuroblasts differentiate At this point, the wall of the neural tube consists of a cavity, lateral wall and roof plate Later on during development > Ependymal layer: ependymal cells (neuroepithelial) lining central canal > Marginal layer (outermost): future white matter, axons entering & leaving mantle layer > Mantle layer: future grey matter, contains neuroblasts - future neurons

Answer 69

Further development (mainly mantle layer), driven by neuroblast differentiation, forms 2 thickenings in dorsal & ventral regions of spinal cord (separated by sulcus limitans) * Alar plate: sensory region, future dorsal horn * Basal plate: motor region, future ventral horn Lumen of neural tube becomes diamond-shaped as a pathway for decussation >Dorsal: roof plate > Ventral: floor plate

Answer 70

Motor nerve fibres arise (week 4) from nerve cell bodies in basal plate of ventral horn Grow out and form a bundle - ventral root Sensory nerve fibres arise from cell bodies present outside spinal cord forming dorsal root ganglia (arise from neural crest cells which migrate here) Processes from dorsal root ganglia grow into dorsal horn Distal processes of sensory and motor nerve fibres grow together forming spinal nerves Spinal nerves divide into > Dorsal rami: dorsal musculature, joints, skin of back > Ventral rami: limbs & ventral body wall, form plexuses

Answer 71

* A alpha: largest, fastest, myelinated, proprioceptors of skeletal muscle * A beta: 2nd largest, fastest, myelinated, mechanoreceptors of skin * A delta, 3rd largest, fastest, myelinated, pain, temperature * C, slowest, narrowest, non-myelinated, temperature, pain, itch

Answer 72

Cervical and lumbar enlargements - More sensory input and motor output given increased number of muscles in upper & lower limbs respectively, which require finer control Autonomic regions - Sympathetic T1-L2 Sympathetic pre-ganglionic cells form the lateral horn * Parasympathetic S2-S4 Parasympathetic pre-ganglionic cells form an intermediate horn (not visible)

Answer 73

Total amount of white matter is smaller in lumbar segments than in cervical ones Number of ascending fibres is greater in rostral segments - each level of the cord contains all the ascending fibres from the lower segments Number of descending fibres is greater in rostral segments - each level of the cord contains all the fibres passing from the brain to more caudal segments

Answer 74

Circle of Willis - anatomical anastomosis formed by: > Internal carotid: gives rise to anterior and middle cerebral arteries > Basivertebral system: gives rise to posterior cerebral arteries > Linked by interconnecting arteries * Anterior communicating artery * Posterior communicating arteries Also supplies cerebellum: * Posterior inferior cerebellar artery (PICA) * Anterior inferior cerebellar artery (AICA)

Answer 75

* ACA: frontal, pre-frontal and supplementary motor cortex, as well as parts of the primary motor and primary sensory cortex * MCA: majority of lateral surface of hemisphere except superior parietal lobe (ACA) and inferior temporal & occipital lobes (PCA); also supplies basal ganglia & part of the internal capsule * PCA: occipital lobe, inferior part of temporal lobe, deep structures (thalamus, posterior limb of internal capsule)

Answer 76

Resting membrane potential arises due to a difference in charge between the inside and outside of the neuron at rest More positive ions outside the cell: Na+ and Cl- More negative ions inside: K+ Concentration gradient moves K+ out of the cell & electric potential gradient forces K+ inside These forces balance out at equilibrium potential, resulting in a negative resting potential inside the cell (-60mV to -70mV)

Answer 77

Voltage-gated ion channels span the neuronal membrane Nerve impulses depolarise the cell > make charge more positive until it reaches threshold (-55 mV) Once threshold is reached, rapid depolarisation opens voltage-gated sodium channels & sodium floods the inside of the cell Positive charge opens voltage-gated potassium channels and repolarisation occurs as potassium exits the cell > potential becomes more negative again Hyperpolarisation occurs > membrane potential becomes more negative to prevent another action potential from occurring

Answer 78

Myelination of axons enables saltatory conduction, where action potentials “jump” from one node to another The cell is only depolarised at each node of Ranvier, enabling faster neurotransmission

Answer 79

Congenital insensitivity to pain Loss-of-function mutation affecting voltage-gated sodium channels (Nav 1.7 - only found on nociceptors) Mutated form means they don’t fire action potentials and patients cannot feel pain Results in serious injury e.g. self-mutilation

Answer 80

* AP enters presynaptic terminal * Voltage-gated calcium channels open following depolarisation; Ca2+ entry * Increase in intracellular Ca2+ allows docking of synaptic vesicles containing neurotransmitters > released via exocytosis * Neurotransmitters diffuse across synaptic cleft and bind to & activate receptors on postsynaptic membrane * Ions (Na+ or Cl-) enter cell (depolarisation or hyperpolarisation) * If total voltage reaches threshold, AP is generated

Answer 81

* Botulism Clostridium bacteria produce botulinum toxin which cleaves specialised proteins needed for docking of synaptic vesicles Disrupts exocytosis, preventing ACh release Clinical features: skeletal muscle weakness, diaphragm paralysis * Myasthenia gravis Auto-antibody binds to ACh receptor on postsynaptic membrane in motor end plate Can induce internalisation or degradation of ACh receptor ACh can no longer bind to receptor Clinical features: severe muscle weakness, ptosis

Answer 82

Excitatory post-synaptic potentials (EPSPs): increase membrane potential & make AP more likely Inhibitory post-synaptic potentials (IPSPs): decrease membrane potential & make AP less likely Summation: * Additive (EPSP + EPSP) = excitatory * Subtractive (EPSP-IPSP) = no change in membrane potential > Temporal: increased frequency of postsynaptic potentials from one site > Spatial: postsynaptic potentials at multiple sites

Answer 83

Divergence: enables a single neuron to communicate and affect change in a wider network E.g. painful stimulus detected by nociceptor, travels to dorsal horn Information diverges - Network of interneurons activated to activate motor neurons - Impulses sent to brain to process pain, localise pain, generate an emotional response, induce learning & memory and engage in protective behaviour Convergence: neuron receives input from a wide network of neurons & acts to integrate information

Answer 84

* EEG: electro-encephalography Records electrical activity in the brain * TMS: transcranial magnetic stimulation Uses electromagnet to stimulate activity in brain; causes depolarisation or interrupted firing Interrupt brain activity while performing a task * PET: positron emission tomography Measures blood flow via a small dose of radioactive material injected into the bloodstream Locate brain activity while performing a task * fMRI: functional magnetic resonance imaging Measures blood flow Locate brain activity while performing a task

Answer 85

Dorsal column/medial lemniscal pathway First-order neuron Receptive ending detects stimulus & AP is generated Axon projects into spinal cord & bifurcates > One branch projects into dorsal horn > One branch projects towards brainstem in the dorsal funiculus Synapses onto second-order neuron in dorsal column nuclei > Gracile nucleus: lower limb; > cuneate nucleus: upper limbs Second-order neuron (cell body in dorsal column nuclei) Axons project out of dorsal column nuclei and decussate to opposite side of medulla via internal arcuate fibres Project up through brainstem in a bundle of axons (medial lemniscus) terminating in thalamus Third-order neuron (cell body in thalamus) Axons project out of thalamus via internal capsule and terminate in appropriate region of somatosensory cortex

Answer 86

Spinothalamic pathway First-order neuron Noxious stimulus activates free nerve endings; AP generated and projects to spinal cord via primary sensory neuron, reaching superficial dorsal horn Synapse onto second-order neurons Second-order neuron Decussate at level of entry into spinal cord; axons reach anterolateral funiculus Project up until they reach thalamus via spinal lemniscus; synapse onto third-order neuron Third-order neuron Sends axons via internal capsule to terminate in appropriate somatosensory region

Answer 87

Upper motor neurons in primary motor cortex descend via internal capsule to brainstem Axons project to midbrain via basis pedunculi towards medulla Axons project down via ventral structures on medulla (medullary pyramids) 85% cross over (pyramidal decussation) to innervate spinal cord 15% ipsilateral Project down along spinal cord to target lower motor neurons at appropriate spinal segments Axons which crossed over form lateral corticospinal tract; travel in dorsolateral funiculus and innervate full spinal cord Axons which stayed ipsilateral form anterior corticospinal tract; travel in ventromedial funiculus and innervate to midthoracic level

Answer 88

* Allows recruitment of cranial nerve nuclei bilaterally * UMN axons project down from primary motor cortex via internal capsule, project down through midbrain via basis pedunculi * Reach specific cranial nerve nuclei * Recruitment of lower motor neurons bilaterally in pons for trigeminal nerve: muscles of mastication * Others project down towards medulla which can innervate vagus (pharynx, larynx, soft palate) or hypoglossal (extrinsic muscles of tongue)

Answer 89

2 principal descending projections that innervate 2 distinct muscle groups * Pontine tracts: innervate extensor muscles Ipsilateral oral and caudal pontine reticular nuclei * Medullary tracts: innervate flexor muscles Ipsilateral gigantocellular reticular nuclei of the medulla Bilateral projections (ipsilateral origins) * Run entire length of cord, conducted in ventral funiculus * Important in maintenance of balance and posture * Modulate activity of alpha motor neurons * Pathology/damage leads to loss of postural control

Answer 90

Origin: contralateral superior colliculus (crossed) in midbrain * Important in balance and posture * Only projects to cervical spinal segments * Innervates head muscles to ensure head position is maintained appropriately

Answer 91

Origin: ipsilateral lateral vestibular (Dieter’s) nucleus of the medulla * Important in maintenance of balance and posture and runs length of spinal cord in ventral funiculus * Modulates activity of alpha motor neurons * Under the influence of the vestibular apparatus in the ear > Helps coordinate the position of the head with the rest of the body

Answer 92

* Meissner’s corpuscle: light touch * Merkel disk: mechanical deflection * Hair follicle receptor: stretch (brushing) * Pacinian corpuscle: vibration and deep pressure * Ruffini ending: deeper in skin; stretching of skin (slippage)

Answer 93

An area of skin where sensation is supplied by a single spinal nerve root

Answer 94

* CNS: anxiety, depression, sleep impairment * Cardiovascular: tachycardia, hypertension * Respiratory: hyperventilation and cough inhibition * Gastrointestinal: ileus, nausea, vomiting * Genitourinary: urinary retention, uterine inhibition * Muscle: > Restlessness due to pain increases O2 consumption > hypoxia > Rigidity due to pain > immobility > DVT risk * Metabolic > Increased catabolic: cortisone, glucagon, GH, catecholamines > Decreased anabolic: insulin, testosterone > Decreased plasminogen: increased coagulation, DVT risk

Answer 95

* Transduction: painful stimulus transduced into AP by nociceptors * Transmission: AP transmitted through nerve fibres (Ad fibres - fast - and C fibres - slow) * Modulation: spinal and supraspinal * Perception: conscious - pain is perceived

Answer 96

Transcutaneous electrical nerve stimulation (TENS) works by stimulating large A beta fibre input overlapping the area of injury & pain Suppresses pain as the inhibitory interneuron is stimulated by a collateral branch of an A beta fibre The other A beta branch will activate the dorsal column/medial lemniscal pathway to block ongoing transmission of C fibre nociception Useful in treating sciatica, rheumatoid arthritis, multiple sclerosis…

Answer 97

Somatic: skin, muscle, bone * Site: well-localised * Radiation: dermatomal * Character: sharp, aching, gnawing * Periodicity: constant +/- incident * Associations: rarely Visceral: internal organs * Site: vague distribution * Radiation: diffuse, to body surface * Character: dull, cramping, dragging * Periodicity: often periodic * Associations: nausea, sweaty, heart rate & BP

Answer 98

* Common descriptors Shooting, electric shock-like, burning, tingling, numbness * Examples: post-herpetic neuralgia, painful diabetic neuropathy * LANSS Pain Scale > 12/24 implies neuropathic pain 5 questions: Prickling, tingling, pins & needles? Altered colour of skin? Abnormally sensitive? Bursts - electric shocks, jumping? Hot or burning? 2 signs: cotton wool allodynia, altered pin-prick threshold

Answer 99

* History, physical, investigations * Characteristics: 10 > Site, radiation, quality, severity, duration, frequency, periodicity > Precipitating & relieving factors, associated phenomena * Brief Pain inventory (BPI) * Impact of pain (physical & mental function), quality of life effects: walking, work, sleep, mood… * To assess severity, use numerical rating, verbal rating or visual analogue * Short form -36 score for quality of life outcomes

Answer 100

Treatment goals: successful if 30-50% pain relief * 6 P’s: > Prevention: back care, exercise, good acute pain control > Pathology: treat underlying cause > Physical therapies: maintain activity, physio, TENS > Pharmacotherapy > Procedural: regional anaesthesia, nerve blocks, steroid injections, epidurals.. > Psychologically-based: support groups, education, pain management program

Answer 101

Step 1: - Paracetamol Long-term side-effects: increase of all cause mortality, CVS events, GI ulcers and bleeds, decreased GFR - NSAIDs or COX II inhibitors Long-term side effects: Upper GI bleeds Major vascular events Renal impairment Step 2: Codeine, dihydrocodeine (often as co-analgesics e.g. co-codamol) Codeine is a pro-drug; metabolised to morphine via first-pass metabolism in liver (CP450 CYP 2D6) Step 3: Morphine, oxycodone, tramadol, buprenorphine, fentanyl

Answer 102

* Nausea (prescribed w/ antiemetic in acute setting) * Sedation/cognitive impairment * Constipation (long-term) * Pruritus (long-term) * Respiratory depression * Insomnia/decreased libido * Addiction/abuse

Answer 103

* Anti-depressants: amitriptyline * Anti-convulsants: gabapentin, pregabalin * Anti-arrhythmics: lidocaine * Others: ketamine, capsaicin, clonidine, cannabinoids

Answer 104

* Tissue damage causes release of potassium ions and prostaglandins (activate free nerve endings) * Bradykinin is released from plasma, 5HT is released from platelets & damaged capillaries * 2 peptides released from free nerve endings > CGRP (vasodilation) > Substance P (plasma extravasation, oedema, bradykinin release) Both activate mast cells, triggering degranulation and histamine release

Answer 105

* Internal carotid * Internal jugular * Common carotid * Vagus nerve (CN X)

Answer 106

* Apex: jugular notch * Superior: inferior border of mandible and a line from its angle to the mastoid process * Anterior: median line from chin to jugular notch * Posterior: anterior border of sternocleidomastoid

Answer 107

* Apex: superior nuchal line * Inferior: middle 1/3 of clavicle * Anterior: posterior border of sternocleidomastoid * Posterior: anterior border of trapezius

Answer 108

* Subclavian artery and vein * Suprascapular & transverse cervical arteries * Apex of lung * Inferior trunk of brachial plexus * Spinal accessory, transverse cervical and great auricular nerves * Suprapleural membrane * Cervical pleura * Thoracic duct * Superficial cervical and supraclavicular nodes * Scalene anterior & medius

Answer 109

Boundaries: T1 vertebra, manubrium, clavicle, upper border of scapula Contents: - Apex of lung - Brachiocephalic trunk - Subclavian artery and vein - Thoracic duct - Vagus nerve and phrenic nerve - Inferior trunk of brachial plexus (ventral rami of C8 and T1) -Cervical sympathetic trunk Cervicothoracic (stellate) ganglion sits against neck of first rib

Answer 110

Upper thoracic spinal cord supplies head: dilator pupillae muscle, sweat glands, smooth muscle of upper eyelid Lateral horn (location of cell bodies) > pre-ganglionic sympathetic fibres descend through ventral root into T1/T2 spinal nerves Bundles go into sympathetic trunk, pass through sympathetic ganglion through middle cervical ganglion Level of the hyoid bone > synapse onto post-ganglionic fibres in large ganglion Post-ganglionic fibres leave superior cervical ganglion & pass to common carotid, reaching destination by running onto arteries

Answer 111

The “sick role” implies that an individual is > Exempt from certain social roles > Not blamed for their illness > Responsibilities include trying to get better, seeking help & cooperating when help is offered. “Illness behaviour” refers to the way in which symptoms are perceived, evaluated & acted upon > Involves the manner in which people monitor their bodies, define & interpret their symptoms and take remedial action

Answer 112

* Internal locus of control (greater sense of agency) * Flexible * Composed (no emotional extremes, no pre-existing psychiatric conditions) * Adequate finances * Social support

Answer 113

* Weakness, fatigue, poor concentration, lethargy * Anhedonia * Anorexia

Answer 114

“Locus of control” refers to how an individual perceives they have control over their own actions as opposed to events occurring because of external forces Internal locus of control * Greater sense of agency, feel empowered to enforce change * Able to effect change in the world around them * Take responsibility External locus of control * World around the individual effects change on them * Feels more helpless * Do not take responsibility

Answer 115

* Enhanced appreciation of life * New opportunities * Change in life priorities * Enhanced sense of purpose * Improved relationships Improve individual’s ability to adjust

Answer 116

Acute: Guillain-Barré syndrome Genetic: Charcot-Marie-Tooth Acquired: B12 deficiency

Answer 117

* Recording and stimulating electrodes * Stimulus added leading to a compound muscle action potential (CMAP) * Measure time taken from stimulus to AP (latency) * Amplitude should stay the same Nerve conduction > Axonal: CMAP falls > Demyelinating: increased latency, change to shape of curve (temporal dispersion) * Helps to locate lesion; stimulation of different points allows identification of site of blockage

Answer 118

Clinical test which is carried out by listening to sounds of muscle Identify neurogenic v myogenic lesions * Allows differentiation of upper v lower motor neuron pathology * Allows differentiation between myopathic (inflammatory) and polymyositic (destructive) conditions

Answer 119

* Nerve conduction studies: repetitive nerve stimulation * EMG: single fibre EMG May show jitter

Answer 120

Symptoms * Sciatica * Constant ache, throbbing pain in lower back * Shooting, burning pain in foot Physical examination * Straight leg raising (SLR) elicits pain by stretching sciatic nerve * Hip, back, knee ROM * Gait, reflexes, strength, testing sensation in relevant dermatomes Imaging: MRI, CT

Answer 121

* Muscles contain muscle spindles which give information about stretch * Information conveyed to CNS by proprioceptive Ia afferents * Synapse onto motor neurons supplying the same muscle * Excitation of motor neurons causes muscle contraction to prevent excessive stretching/tearing Gamma motor fibres: contraction of spinal cells Alpha motor neuron fibres: innervate muscles within which muscle spindles are embedded

Answer 122

Sensory ending enclosed in connective tissue that lies near the junction of a tendon with a muscle Nerve endings associated with collagen fibres within tendons Provides proprioceptive information which complements information provided by muscle spindles Prevents excessive tension in muscles; synapse with inhibitory interneuron leads to muscle relaxation

Answer 123

Helps maintain posture Slight lean to either side causes a stretch in the spinal, hip and leg muscle spindles on the other side of the body > Quickly countered by the stretch reflex, which keeps us upright

Answer 124

Spinal shock is the temporary suppression of all reflex activity below the level of a spinal cord injury (SCI), occurring immediately after injury Autonomic dysfunction appears * Blood pressure and heart rate instability * Neurogenic bladder * Autonomic dysreflexia (T6 and above) * Temperature control * Sexual dysfunction

Answer 125

* Contain axons from 2 functionally distinct types of nerve cells: sensory afferent and motor efferents * Axons can be myelinated or unmyelinated * Within the nerve trunk, fasciculi are found > A fascicle is a bundle of axons from individual cells surrounded by perineurium * Epineurium, a tough connective tissue, surrounds the peripheral nerve

Answer 126

Neurogenic shock is the body’s response to a sudden loss of sympathetic control, resulting in distributive shock Occurs in SCI above T6, > 50% loss of sympathetic activity Clinical triad of hypotension, bradycardia and hypothermia

Answer 127

Symptoms * Paralysis in arms, hands, trunk, legs * Tetraplegia or quadriplegia * Patient may be unable to breathe (C3-C5) or speak * Control of bladder/bowel movements may be affected Consequences * Complete assistance with activities of daily living * Require indwelling catheter * Psychological impact * DVT, pressure areas * Pain * Sexual dysfunction & conception issues

Answer 128

* Varying degree of arm function * Likely able to breathe on their own and speak normally * Still very dependent on others for activities of daily living

Answer 129

Thoracic: paraplegic with truncal involvement Lumbar/sacral: lower limbs affected, little or no control over bladder & bowel

Answer 130

Jendrassik reinforcement manoeuver * Upper limb: clench teeth * Lower limb: pulling interlinked fingers in opposite directions Combination of distraction and cortical inhibition from anterior horn cells reinforces reflexes

Answer 131

Single afferent axon with all its sensory receptor endings and the area of skin they are localised to Each unit has its own receptive field For sensation to be perceived, the stimulus must fall in a receptive field which recognises that modality

Answer 132

The idea that for 2 stimuli to be perceived as separate, they must activate different receptors To activate separate receptors the stimuli must fall within separate receptive fields

Answer 133

* Appearance of notochord and mesoderm induces overlying ectoderm to thicken and form a neural plate (cephalic area) * Neural plate lengthens and lateral plates elevate, creating neural folds: 19d * The depression in the centre is known as the neural groove * Folds move towards each other and fuse in the midline, forming the neural tube

Answer 134

1st arch - maxilla, mandible, zygomatic bone, part of temporal bone, incus, malleus, muscles of mastication, muscles of floor of mouth, tensor tympani 2nd arch - stapes, styloid process, hyoid bone, muscles of facial expression, stapedius 3rd arch - common carotid, stylopharyngeus, hyoid bone 4th arch - subclavian artery, aortic arch, laryngeal cartilages 6th arch - pulmonary arteries, ductus arteriosus

Answer 135

Controlled through * Cell wedging: microtubules and microfilaments changing cell shape, cell cycle * Hingepoints: median and dorsolateral hinge points * Extrinsic forces: pushing of the surface ectoderm, adhesion point with notochord

Answer 136

Fusion begins in the cervical region and proceeds in cephalic and caudal directions Open ends of the tube form anterior and posterior neuropores Closure occurs in week 4 Anterior: day 25 Posterior: day 27

Answer 137

Function: regulation of cerebral blood flow Blood flow remains constant despite variability in blood pressure (60-100mmHg) Vessel diameter reduces as blood pressure increases

Answer 138

A stroke is a focal neurological disturbance that arises due to a disturbance in blood flow to the brain Ischaemic: blockage of blood vessel Causes - Direct damage - Blood clot lodged in vessel (can arise from carotid artery or heart - AF) Consequences: can be treated, potentially improving outcomes Haemorrhagic: burst vessel, blood fills space inside brain Causes: hypertension, arteriovenous malformation (AVM) Consequences: treatment is more difficult, poor prognosis

Answer 139

Aging results in loss of outer hair cells, loss of “cochlear amplifier” * Loss of frequency discrimination * Loss of dynamic range: too quiet to hear then uncomfortably loud * Affects understanding of speech, mainly high frequencies

Answer 140

* Flocculonodular lobe (aka vestibulocerebellum) > Location: vermis > Function: balance and spatial orientation > Input: vestibular system > Output: fastigial nucleus, brainstem vestibular nuclei * Spinocerebellum > Location: adjacent to vermis > Function: fine tune axial and limb movements > Input: spinal cord > Output: cortex and brainstem via deep cerebellar nuclei * Neocerebellum > Location: lateral lobes > Function: planning movement and evaluating sensory input > Input: cerebral cortex/pontine nuclei > Output: thalamus, red nucleus (midbrain)

Answer 141

Symptoms: * Slurred speech * Coordination difficulties * Tremor * Gait unsteadiness/falls Signs: * Nystagmus * Dysarthria * Dysdiadochokinesia * Heel-shin ataxia

Answer 142

BBB consists of a series of features which prevent harmful substances from entering the brain & spinal cord from the blood > Capillaries in nervous tissue - Thick continuous basement membrane, tight junctions, astrocyte processes covering vessel Ependymocytes: line ventricles & spinal canal, tight junctions restrict movement Functions: * Keep out toxins, pathogens * Prevent fluctuation of ions, nutrients, metabolite concentrations in CNS * Permeable to substances that can diffuse across (water, gases, small lipophilic molecules) * Active transport for specific substances e.g. glucose, amino acids

Answer 143

* Cell bodies of olfactory cells found in olfactory mucosa * Axons pass through holes in cribriform plate and enter olfactory bulb (swollen end of olfactory nerve) * Olfactory nerve sits under frontal lobe on floor of anterior cranial fossa, above roof of nose * Axons from groups of olfactory cells converge on a glomerulus in the olfactory bulb * Pattern of glomerular activation encodes which odour has been detected

Answer 144

Olfactory nerve projects centrally without relaying through the thalamus * Rhinencephalon: “smell brain” >Anterior olfactory nucleus: olfaction > Piriform cortex: olfaction > Olfactory tubercle: intergrates olfaction with other senses (social behaviour, reward, addiction) > Entorhinal cortex: memory, perception of time * Limbic system > Amygdala: memory, decision-making, fear, anxiety, aggresion > Hippocampus: memory > Parahippocampal gyrus: memory

Answer 145

Striking the patellar tendon causes stretch of the quadriceps muscle Afferent signal sent through sensory neurons up through dorsal root ganglion, enters dorsal horn (L3/L4) & synapses onto motor neuron Efferent signal causes contraction of quadriceps Afferent signal also works through interneuron - has an inhibitory effect on motor neurons going to the hamstrings (antagonist muscles), which relax

Answer 146

* 3 turbinates (nasal conchae): superior, middle, inferior * 3 types of mucosa: nasal, olfactory, respiratory * Semilunar hiatus: crescent-shaped groove in the lateral wall of the nasal cavity (middle meatus) - opening for maxillary sinus * Opening to Eustachian tube is in the nasopharynx (lateral wall) * Posterior nasal aperture (choanae): opens into nasopharynx

Answer 147

* Ethmoid * Frontal * Maxillary * Sphenoid Function: reduce weight of skull, increase resonance of sound, allow circulation of mucus Drain into nasal cavity

Answer 148

* Lingual * Palatine * Pharyngeal or “adenoid” * Tubal

Answer 149

Right and left palatoglossal folds The isthmus of the fauces is the boundary between the oral cavity and the oropharynx

Answer 150

Pharyngeal recess immediately posterior to the auditory tube Clinical significance: a mass in the nasopharynx could block the auditory tube > its middle section is made of cartilage and could be compressed > Loss of air entry into the middle ear can result in excess mucus production

Answer 151

* All innervated by vagus (CN X) via the pharyngeal plexus - Exception: stylopharyngeus, which is innervated by the glossopharyngeal nerve (CN IX)

Answer 152

* Pharyngeal constrictors: superior, middle and inferior * Longitudinal muscles (elevators): lift pharynx to receive food from oral cavity > Stylopharyngeus: elevates pharynx & larynx > Palatopharyngeus: approximates soft palate and posterior wall of pharynx > Salpingopharyngeus: elevates pharynx; opens auditory tube when swallowing

Answer 153

Elastic cartilage that closes and covers laryngeal inlet during eating/drinking to prevent entry of foreign substances into lungs

Answer 154

Depression behind the root of the tongue which serves as a spit trap * Saliva is held there to prevent the initiation of a swallow reflex

Answer 155

Larynx protects the opening of the trachea * Contains vocal cords (aka vocal folds) > 2 folds of mucous membrane that vibrate and modulate the flow of expelled air in phonation * Contains vestibular folds (false vocal cords) - folds of mucous membrane that enclose vestibular ligaments * Rima glottidis: opening between the true vocal cords and arytenoid cartilages

Answer 156

* Cricothyroid: changes the length of vocal cords to alter pitch of voice * Thyroarytenoid: changes the length of vocal cords to alter pitch of voice * Posterior cricoarytenoid: opens the vocal folds (abductor) * Lateral cricoarytenoid and transverse arytenoid: close rima glottidis (adductors) * Oblique arytenoid: acts as a purse-string, contributing to closure of laryngeal inlet w/ aryepiglottic muscle

Answer 157

All intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve except for cricothyroid - supplied by external branch of superior laryngeal nerve Sensation: (vagus nerve, CN X) * Above vocal folds: branch of superior laryngeal nerve * Below vocal folds: branch of recurrent laryngeal nerve

Answer 158

* Arytenoid cartilages: pair of small, 3-sided pyramids to which vocal cords attach, enabling movement * Cuneiform tubercle: paired cartilages attached to arytenoids; support vocal cords and lateral epiglottis * Aryepiglottic folds: 2 ligamentomuscular structures in supraglottic larynx > Protect airway while swallowing; lateral border of laryngeal inlet > Landmark for intubation * Pyriform fossae: one on either side of aryepiglottic fold; common place for food to be trapped

Answer 159

Glue ear, also known as otitis media with effusion, is caused by a blockage of the auditory tube > Leads to the accumulation of fluid within the middle ear due to poor ventilation Treatment - Insertion of ventilation tubes: ventilate the middle ear cavity

Answer 160

* Nasopharynx > Base of skull to soft palate * Oropharynx: > Soft palate to epiglottis * Laryngopharynx > Epiglottis to bifurcation of oesophagus and trachea

Answer 161

* Arousal: general state of wakefulness and responsivity * Vigilance: capacity to maintain attention over prolonged periods of time * Divided attention: ability to respond to more than one task * Selective attention: ability to focus on one stimulus while suppressing competing stimuli

Answer 162

1. Delirium/acute confusional state 2. Drowsiness 3. Impersistence 4. Distractible

Answer 163

* Top-down cortical attentional modulation > Frontal, parietal and limbic cortices > Might be affected by hyperarousal: fear, anxiety, pain > Impairs attentional processes: inattention, neglect * Bottom-up attentional competition > Visual, auditory, somatosensory association cortices * Arousal mechanisms: ascending reticular activating system > Grey area in brainstem projecting upwards and maintaining arousal

Answer 164

* 4AT-screen for delirium > Alertness Ask age, date of birth, place, year… Attention (months of the year backwards) Acute change or fluctuating course

Answer 165

- Registration > Alertness > Attention-RAS > Thalami > Frontal cortices * Encoding > Medial temporal (including hippocampus) * Retrieval > Reactivation of temporal structures > Frontotemporal crosstalk * Consolidation > Diffuse cortices

Answer 166

* Holds information temporarily e.g. remembering a phone number * Involves active maintenance and manipulation of information in short-term storage * Can usually hold 7+/- 2 elements

Answer 167

* Implicit memory/procedural: network involves basal ganglia & cerebellum * Episodic memory/declarative: personal experience > Extended limbic system (circuit of Papez) > Medial temporal lobe: hippocampus & entorhinal cortex > Diencephalon: mamillary bodies & thalami > Parts of memories e.g. vision, olfaction may be located in regions associated w/ these functions > Amygdala is associated with emotional memories * Semantic memory: facts - semantic memory network > Left hemisphere anterior temporal lobe - key integrative region > Anterior temporal cortex (ATC) and angular gyrus (AG) integrate incoming information * Verbal v visual

Answer 168

* Pure amnesia > Transient global amnesia: individual knows who they & other people are but keeps repeating things > Transient epileptic amnesia: recurrent spells of memory loss, short in duration, happen soon after waking * Mixed deficit: delirium

Answer 169

* Pure amnesia > Hippocampal damage * Herpes simplex virus (HSV encephalitis) * Anoxia * Alzheimer’s disease > Diencephalic damage * Korsakoff’s syndrome * Bilateral thalamic stroke * Post subarachnoid haemorrhage * Mixed deficit: dementia

Answer 170

Addenbrooke’s cognitive examination - ACE III

Answer 171

* Inputs > Comprehension: dysfunction (agraspia) > Reading: dysfunction (alexia) > Repetition - Outputs > Speech: dysfunction (aphasia) > Sign language/gesture > Naming: dysfunction (anomia) > Writing: dysfunction (agraphia) > Repetition

Answer 172

- Broca's area > Left frontal: language production > Dysfunction: - Non-fluent - Effortful/difficulty articulation errors - Wernicke's area > Left frontal: comprehension > Dysfunction: - Fluent - Nonsense

Answer 173

Arcuate fasciculus

Answer 174

* Prefrontal cortex (divided into 3 main areas) > Dorsolateral prefrontal cortex Executive functions / dysfunction: - Sequencing / trouble sequencing - Organisation / disorganisation - Abstraction / concrete thinking - Planning / poor planning > Orbitofrontal prefrontal cortex Executive functions / dysfunction - Social interactions / loss of social niceties - Behaviour / loss of table manners - Insight / lack of insight - Inhibition / disinhibition > Ventromedial prefrontal cortex Executive functions / dysfunction - “Get up and go” / apathetic

Answer 175

Progressive and selective dysfunction or loss of neurons associated with deposition of pathologically altered proteins that leads to disruption of functional systems and clinical symptoms

Answer 176

6 soluble isoforms exist Roles: * Maintain stability of axonal microtubules * Protein translation * Cellular signalling * Apoptosis Hyperphosphorylation of tau can lead to neurodegenerative disease - Formation of insoluble neurofibrillary tangles of helical and straight filaments

Answer 177

* Alzheimer’s disease * Frontotemporal dementia * Corticobasal degeneration (CBD) * Progressive supranuclear palsy (PSP) * Chronic Traumatic Encephalopathy (CTE)

Answer 178

* Primarily affects > 65 y/o and co-exists with vascular dementia - Clinical presentation > Progressive memory loss > Executive dysfunction > Loss of social and occupational functioning > Visuospatial difficulties > Personality change * Pathology > Beta-amyloid plaques > Intracellular neurofibrillary tangles of tau > Results in neuronal loss, brain atrophy and reduced acetylcholine synthesis > Process starts in entorhinal cortex and moves onto hippocampus

Answer 179

* Mean age of onset 53-58y/o * Positive family history is common - Clinical presentation > Change in personality/social conduct > Coarsening of personality > Indifference to others > Disinhibition > Parkinsonism * Pathology > Atrophy in frontal/temporal regions > Hypoperfusion in affected regions > Intraneuronal and glial tau deposition

Answer 180

* Mean age of onset 63y - Clinical presentation > Parkinsonism > Vertical gaze palsy > Dementia > Postural instability/falls Pathology: > Interneuronal and glial cell tau deposition within basal ganglia, brainstem and cortex > Midbrain atrophy

Answer 181

* Mean age of onset 63y - Clinical presentation > Asymmetric parkinsonism > Apraxia and dystonia > Alien limb phenomenon > Cortical sensory loss > Aphasia * Pathology > Tau deposition within basal ganglia and frontoparietal cortices > Ballooned neurons > Asymmetrical cortical atrophy affecting superior parietal lobe

Answer 182

* Sequelae of chronic repeated head injury * Clinical presentation > Behavioural change > Cognitive difficulties > Mood disturbance Pathology: widespread cortical tau deposition

Answer 183

* Unstructured soluble protein encoded by SNCA gene with a role in DNA repair * Misfolded alpha synuclein along with ubiquitin and neurofilament proteins form Lewy bodies * Lewy bodies: intracytoplasmic inclusion bodies that eventually lead to cell death

Answer 184

* Parkinson’s disease * Dementia with Lewy bodies * Multiple systems atrophy (MSA)

Answer 185

Long prodromal period, prevalence increases >65y/o Clinical presentation - Motor > Rest tremor > Rigidity > Bradykinesia > Postural instability - Non-motor > Mood disturbance > REM sleep behaviour disorder > Hyposmia > Constipation Lewy body pathology starts in gut, ascending to brainstem & substantia nigra

Answer 186

Clinical presentation: * Parkinsonism * Progressive cognitive difficulties * Visual hallucinations * Fluctuation in cognition * Sensitivity to antipsychotic medication Pathology: * Lewy body deposition in brainstem and cortex * Co-existence with Alzheimer’s pathology is common

Answer 187

Clinical presentation - Parkinsonism with prominent cerebellar or autonomic features > Postural hypotension and genitourinary dysfunction Pathology - Lewy body deposition predominantly in oligodendrocytes within > Brainstem > Striatum > Cerebellum

Answer 188

Creutzfeldt-Jakob disease: rare and rapidly fatal Prions are tiny misfolded proteins that form aggregates Clinical presentation * Rapid onset dementia and behaviour change * Myoclonic jerks * Visual disturbances * Ataxia Pathology * Spongiform vacuolation throughout grey matter * Reactive proliferation of astrocytes & microglia * Neuronal cell loss Investigations: lumbar puncture, EEG, MRI shows cortical ribboning

Answer 189

Huntington’s disease: autosomal dominant inheritance * Caused by expansion of CAG repeats in huntingtin gene (chromosome 4) Clinical presentation: * Chorea * Behavioural change * Psychiatric disturbance * Dementia MRI/CT shows caudate atrophy

Answer 190

* Sclera: white of the eye, fibrous elastic tissue, covered by conjunctivae * Pupil: darkened hole in the centre of the iris controlling passage of light * Iris: coloured part of eye, smooth muscle controls diameter of pupil * Choroid: vascular layer in posterior eye between sclera and retina * Cornea: avascular transparent structure covering the front of the eye * Anterior & posterior chambers: aqueous humour produced by ciliary bodies maintains pressure and provides nutrients

Answer 191

* Optic nerve (CN II) carries visual impulses to occipital lobe * Lens: focuses visual input to the back of the retina * Macula: near the centre of the retina, responsible for detailed central vision * Retina: light-sensitive layer of tissue containing rods and cones * Vitreous chamber: contains vitreous humour, gel-like structure between lens and retina; contains phagocytes to remove cell debris

Answer 192

* Controlled by hypothalamus * Fibres travel ipsilaterally to lateral column of cervical spinal cord, ciliospinal centre (C8-T2) * Second-order pre-ganglionic pupilomotor fibres exit spinal cord at T1 * Enter cervical sympathetic chain synapsing in superior cervical ganglion * Post-synaptic fibres travel through internal carotid plexus * Enter cranium and join ophthalmic division of trigeminal nerve (V1) * Enter orbit through superior orbital fissure, fibres travel with long ciliary and nasociliary nerves * Contain alpha adrenergic sympathetic receptors

Answer 193

Symptoms: gradual loss of central vision and distortion Pathophysiology: * Accumulation of cellular debris (drusen) between retina and choroid * Atrophy of retinal pigment epithelium and photoreceptors Treatment: No cure Lifestyle advice: diet Low visual aids, magnifiers, partial sight/blind registration

Answer 194

Symptoms: gradual/rapid loss of central vision and distortion Pathophysiology: * Choroidal neovascularization stimulated by VEGF * Grow under retinal pigment epithelium, cause haemorrhage, leakage and ultimately fibrosis * Disrupt photoreceptor and retinal function * Loss of vision is profound if untreated Treatment: * anti-VEGF antibodies: intravitreal injection * Inhibits angiogenesis, reducing leakage & haemorrhage * Preserve vision/delay visual loss * Not a cure, repeat monthly for at least 3 months

Answer 195

* Foliate (leaf-shaped) > Vertical ridges on side of tongue * Filiform (string-shaped) > Thread-like structures create rough surface to help with speaking, chewing and cleaning oral cavity * Fungiform (mushroom-shaped) > Carry 2000-8000 taste buds > Distributed across tongue > Gustatory receptor cells detect 5 chemicals dissolved in saliva * Vallate: > Approx a dozen form V-shaped line (boundary between anterior 2/3 and posterior 1/3) > Carry some taste buds and minor salivary glands

Answer 196

* Substance from food dissolves in saliva * Saliva enters taste pore and gustatory receptor cell depolarises * Nerve impulse travels along afferent nerve to brain * Surrounded by supporting (sustentacular) cells * 5 chemicals detected > Salty: Na+ ions and others in same group > Bitter: protective function e.g. coffee, beer > Sour: hydrogen ions > Sweet: sugars > Savoury/umami: monosodium glutamate

Answer 197

* Anterior 2/3 > General sensation - pain, temperature, touch: lingual nerve, branch of mandibular division of trigeminal nerve (CN V3) > Taste - chorda tympani, branch of facial nerve (CN VII) Initially runs in lingual nerve & then passes to chorda tympani Chorda tympani travels through middle ear behind TMJ on undersurface of eardrum, joining the facial nerve behind the eardrum - Posterior 1/3 Glossopharyngeal nerve (CN IX) for both general sensation and taste

Answer 198

* CN IX and CN VII run to brainstem and taste fibres synapse in the nucleus tractus solitarius (NTS) of the medulla * Second-order neurons travel to thalamus * Third-order neurons project to gustatory cortex > Undersurface of frontal lobe, covered by temporal lobe > Anterior insula, inferior frontal gyrus

Answer 199

* Genioglossus: protrusion of the tongue * Palatoglossus: elevates root of tongue, depresses soft palate * Styloglossus: retracts and elevates lateral tongue * Hyoglossus: depression of tongue All innervated by the hypoglossal nerve (CN XII) except for palatoglossus (vagus nerve, CN X)

Answer 200

* Genioglossus: protrusion of the tongue * Palatoglossus: elevates root of tongue, depresses soft palate * Styloglossus: retracts and elevates lateral tongue * Hyoglossus: depression of tongue All innervated by the hypoglossal nerve (CN XII) except for palatoglossus (vagus nerve, CN X)

Answer 201

Intrinsic muscles change the shape of the tongue * Vertical: broadens & elongates the tongue * Transverse: narrows & elongates the tongue * Longitudinal: retracts & broadens tongue

Answer 202

* Buccal phase (voluntary) Tongue moves against hard palate to push bolus into pharynx * Pharyngeal stage (involuntary) Movement of bolus into oropharynx triggers receptors Send impulses to deglutition centre (medulla & lower pons) Signals sent to uvula and soft palate to close nasopharynx; epiglottis seals larynx Upper oesophageal sphincter relaxes to allow passage of bolus * Oesophageal stage (involuntary) Bolus pushed onwards by peristalsis

Answer 203

Submental lymph nodes * Anterior lower mouth * Lower lip * Front of mouth * Anterior teeth * Tip of tongue * Skin of chin Submandibular lymph nodes * Cheeks * Gums * Upper lip * Anterior tongue * Nasocavity * Maxillary sinus * Lower part of face

Answer 204

* Submental and submandibular * Paratracheal * Superficial cervical * Supraclavicular * Jugulo-omohyoid (deep cervical): drains tongue * Jugulo-digastric (deep cervical): drains palatine tonsil and tongue * Mastoid: drain posterior neck, upper ear & back of external auditory meatus * Occipital: drains occipital area of scalp * Parotid (pre-auricular): drains superficial areas of face & temporal region * Retro-auricular * Sublingual

Answer 205

* Episodic events - Deteriorating cortical function > Coma/altered consciousness > Seizures: status epilepticus > Encephalitis > Encephalopathy: widespread cortical dysfunction, not seizure activity > CJD/dementia > Prognosis in hypoxic brain injury > Rare dementia/cognitive decline * Attack disorders > First/single seizure: prognosis > Firm clinical diagnosis & classification of epilepsy * Focal or generalised discharge?

Answer 206

* Measurement of central conduction in the CNS * Provide a stimulus and measure the response * Categories > Visual evoked potentials (VEP) Assess macular-cortical pathway’s gross integrity P100: discharge that arrives after 100ms at occipital cortex > Brainstem auditory evoked potentials (BAEPs) Operations around brainstem Apply sound stimulus to the ear and relate peaks to aspects of hearing pathway

Answer 207

Vibrating tuning fork placed on mastoid bone; ask patient to tell you when sound can not be heard Then place near auditory canal until they can’t hear it Used to compare the perception of sounds transmitted by air conduction compared to bone conduction Screens for the presence of conductive hearing loss: bone conduction is louder than air conduction due to blockage Normal: air conduction is louder than bone conduction (same with sensorineural hearing loss but they will stop hearing it sooner)

Answer 208

Superior & inferior sagittal sinus, as well as straight sinus, anastomose at internal occipital protuberance Transverse sinuses emerge from this and form the sigmoid sinuses Sigmoid sinuses drain into the internal jugular vein via the jugular foramen Cavernous sinus is located anteriorly & received blood from ophthalmic veins Drains into superior & inferior petrosal sinuses which drain into internal jugular

Answer 209

21 denticulate ligaments laterally Stop movement due to lateral vertebral displacement

Answer 210

* Sickle-shaped midline fold separating 2 hemispheres * Posterior border blends w/ tentorium cerebelli * Anterior border attaches to crista galli (ethmoid bone) * Upper border attached to vault midline & contains superior sagittal sinus

Answer 211

Tent-shaped fold roofing over posterior cranial fossa Divides cranial cavity into * Supratentorial compartment: contains hemispheres, specifically lower aspect of occipital lobes * Infratentorial compartment: contains brainstem and cerebellum; midbrain passes through tentorial hiatus

Answer 212

The lentiform nucleus consists of the putamen and the globus pallidus The striatum consists of the putamen, globus pallidus and caudate nucleus