Neurology Flashcards
Name the meninges in order
Dura mater
Arachnoid mater
Pia mater
Which meninge has two layers which surround the venous sinuses?
Dura mater
Has a periosteal layer and a meningeal layer.
Which meninge contains the cerebrospinal fluid?
Arachnoid mater
Which meninge is tightly bound to the surface of the brain?
Pia mater
Which fascial layers divide the brain into sections? What is their function? What are they made of ?
Falx cerebri
Tentorium cerebelli
Prevent brain rotating within the skull
Made of reflections of dura mater
Which bony ridge does the falx cerebri attach onto?
Crista Galli of ethmoid
What is the blood supply to the scalp?
Aponeurosis of superficial temporal arteries and occipital arteries
Why does the scalp bleed so heavily? Why does the bone underneath not suffer from necrosis?
It is an Aponeurosis direct from external carotid.
The vessels can’t constrict because they are tightly bound to connective tissue
Bone underneath supplied by middle meningeal arteries
What type of bleed from which vessel usually causes an extradural haematoma?
Forceful arterial - usually middle meningeal
What type of bleed from which vessel usually causes an subdural haematoma?
Venous - veins between brain and venous sinuses
What type of patient is particular risk factor for a subdural haematoma?
Elderly with dementia.
Brain atrophies leaving longer sections of veins to sinuses exposed. Smaller brain also means more rotation in the cranial cavity so greater shearing forces.
How would you identify a sub arachnoid haemorrhage?
Pinkish CSF
Mri covered in white
Give 3 functions of cerebrospinal fluid.
Buoyancy and reduced weight
Homeostasis
Mechanical protection
How is CSF produced?
Choroid plexus in the lateral ventricles filters blood
Describe the flow of cerebrospinal fluid through the nervous system.
Produced in lateral ventricles - foramen of monro - 3rd ventricle - cerebral aqueduct - 4th ventricle
Then either - spinal canal or medial and lateral apertures to sub arachnoid space
Drains back to venous sinuses through arachnoid villi
What does a yellowish CSF indicate?
Infection eg meningitis
Which bacteria are implicated in meningitis?
Streptococcus pneumoniae
Or
Neisseria meningitidis
Why is meningitis so dangerous?
Inflammation and oedema raises intracranial pressure
Risk of decreased perfusion and/or cranial herniation (coning)
Give 4 key diagnostic symptoms of meningitis other than fever and headache.
Photophobia
Confusion
Stiff neck
(Later) rash due to sepsis
In which condition is congenital hydrocephalus common? Why?
Spina bifida
Notochord does not close properly so ventricles not complete.
Struggle to maintain pressure of CSF so excess is produced
Name the layers of the scalp
Skin Connective tissue Aponeurosis Loose connective tissue Periosteum
What are the 3 main arteries which are supplied by the circle of Willis?
Anterior middle and posterior cerebral arteries
Which areas of the brain are supplied by the anterior, middle and posterior cerebral arteries?
Anterior - medial full thickness strip, as far back as the occipital lobe
Middle - most of parietal and temporal lobes
Posterior - occipital lobe and inferior temporal lobe
Give 3 key functions of the frontal lobe
Executive function
Decision making
Motor function
Give 3 key functions of the parietal lobe
Somatosensory
Spatial awareness and perception
Broca’s speech
Give the key function of the occipital lobe
Primary visual cortex
Give 3 key functions of the temporal lobe
Wernicke’s - language
Hearing
Memory - hippocampus
What are the 3 main arteries that supply the brain?
2 internal carotids Vertebral artery (-basilar)
What do the external carotids supply?
Facial
Maxillary - middle meningeal (skull and meninges)
Superficial temporal - (scalp)
Where is the carotid sinus located? What is its clinical significance? What is its nerve supply?
Bifurcation of the common carotid
Location of baroreptors
Innervated by Glossopharyngeal
Where is atheroma build up common in the head and neck? Why?
Carotid sinus due to turbulent flow of blood
Where are intracerebral aneurysms most common? Why are they dangerous?
Circle of Willis
Risk of rupture
Give 4 broad causes of stroke
Thrombus
Embolus eg from carotid thrombus
Hypoperfusion eg in shock
Haemorrhage/ haematoma causing hypoperfusion and pressure necrosis
Which vein is used to measure jugular venous pressure (JVP)? Why?
Internal jugular vein
Drains closest to right atrium and pulsatile due to valve in inferior bulb.
Pulsation level gives good approximation of right atrial pressure
Where do the dural venous sinuses drain to?
Internal jugular vein
Where does blood from the scalp and face drain to?
Follows arteries to internal and external jugular veins
Which 2 disorders are caused by the failure of the notochord to fuse?
Cranially - anencephaly
Caudally - spina bifida
How can incidence of spina bifida be reduced?
Folic acid taken prior to conception and during the first trimester
How is the cauda equina formed?
Vertebral column grows faster than the spinal cord. The nerve roots below L1 are forced to extend.
What is cauda equina syndrome? How is it caused?
Trauma to L3/L4 affects S3-S5 dermatomes because the roots of these dermatomes start higher up.
Leads to saddle anaesthesia
Caused by trauma eg epidural or lumbar puncture.
Where is the correct site of a lumbar puncture? Why?
L3-L5 because it is below the end of the spinal cord
What causes the sulci and gyri of the brain?
Growth within the fixed cranial cavity
What is the prosencephalon? What are its derivatives?
Forebrain
Telencephalon - cortex
Diencephalon - thalamus
What is the mesencephalon? What are its derivatives?
Midbrain - midbrain stuctures
What is the rhombencephalon? What are its derivatives?
Metencephalon - pons and cerebellum
Myelencephalon - medulla
Where do neural crest cells arise? How are they formed?
Cells that arise on the lateral border of the neural tube.
Formed by epithelial to mesenchyme transition.
What are the derivatives of neural crest cells?
Lots of types of specialised cells
Eg Schwann, glia, ganglia, melanocytes, smooth muscle etc
Which types of embryological cells are most sensitive to alcohol?
Neurectoderm - particularly neural crest cells
What are the derivatives of the 1st pharyngeal arch?
Nerve - trigeminal Cartilage - mandible Artery - none Pouch - auditory canal Cleft - tympanic membrane
What are the derivatives of the 2nd pharyngeal arch?
Nerve - facial Cartilage - stapes, styloid, hyoid Artery - none Pouch - palatine tonsils Cleft - none
What are the derivatives of the 3rd pharyngeal arch?
Nerve - Glossopharyngeal Cartilage - none Artery - internal carotid Pouch - thymus and parathyroid Cleft - none
What are the derivatives of the 4th pharyngeal arch?
Nerve - vagus (superior laryngeal) Cartilage - epiglottis, thyroid, cricoid Artery - aortic arch, brachiocephalic, subclavian Pouch - thyroid gland Cleft - none
What are the derivatives of the 6th pharyngeal arch?
Nerve - Vagus (recurrent laryngeal) Cartilage - arytenoid Artery - pulmonary arteries Pouch - none Cleft - none
What is the path of the recurrent laryngeal nerve on the left and right? Why is it like this?
Forms from the 6th arch so has to loop around the 4th arch to get where it wants
On the right that is just the subclavian artery
On the left that is the arch of the aorta and the ductus arteriosus
How does the oral cavity develop embryologically?
Stomatadeum contains buccopharyngeal membrane
No mesoderm so obliterated
How does the nose develop embryologically?
Nasal placodes in the frontonasal prominence grow into pits.
They are pushed medially by the growth of the maxillary prominence below.
The nasal septum grows down to join the palate
How does the palate develop embryologically?
Fusion of nasal pits in frontonasal prominence forms primary palate - philtrum, four incisors and lip.
Maxillary palatal shelves from 1st arch grow into midline to form secondary palate.
All fuse
How do the eyes develop embryologically?
Outgrowth of diencephalon on side of head
Pushed medially by growth of facial prominences
How do the ears develop embryologically?
Auditory canal develops in 1st cleft in neck
Auricle grow from 2nd arch
All pushed up and in by growth of mandible
What is the cause of a cleft lip / palate?
Lip - failure of primary and secondary palate to fuse together
Palate - as above plus the failure of palatal shelves to meet in midline
What are the anterior and posterior pituitary gland derived from?
Anterior - rathke’s pouch - pinched off ectoderm
Posterior - infundibulum - pinched off neuroectoderm
Where does the thyroid originally develop? Where does it descend to? What is the clinical significance of this?
Foramen cecum at 2nd arch
To level of 4th arch
Can leave ectopic thyroid behind
What is the function of the dorsal column?
Fine touch, vibration and conscious proprioception
Where does the dorsal column decussate?
Medulla oblongata
Where are the cell bodies of the 1st, 2nd and 3rd order neurons of the dorsal column?
1st - dorsal root ganglion
2nd - nucleus cuneatus/ gracilis
3rd - thalamus
Where are the cell bodies of the 1st, 2nd and 3rd order neurons of the spinothalamic tract?
1st - dorsal root ganglion
2nd - dorsal horn
3rd - thalamus
Where does the spinothalamic tract decussate?
Spinal cord
What is the function of the spinothalamic tract?
Crude touch
Pressure
Pain and temperature
What is the function of the spinocerebellar tract?
Unconscious proprioception
Why is some sensory information unconscious?
Some proprioception is unconscious because it travels through the spinocerebellar tract and avoids the cortex.
What symptom would be associated with damage to the dorsal column? Give two possible causes.
Loss of conscious proprioception - ataxic gait
Vitamin B12 deficiency, neurosyphilis
What symptom would be associated with damage to the spinothalamic tract? Give a possible cause.
Loss of pain sensation
Syringomyelia - swelling of spinal canal pushes on spinothalamic where it decussates. Affects bilaterally.
What is the name given to the pattern of sensory loss in peripheral neuropathy? Give two possible causes.
Glove and stocking
Diabetic neuropathy
Guillain barre syndrome
What is Brown-Sequard syndrome?
Traumatic hemi section of spinal cord
Causes ipsilateral loss of dorsal column (fine touch)
Contralateral loss of spinothalamic (pain and temperature)
Which neuron in the sensory pathway is damaged in a peripheral neuropathy?
1st order
What is referred pain?
Pain felt in a site incongruous with the site of damage.
Caused by visceral sensory afferents hijacking the somatosensory afferents at a particular spinal level.
What is the function of the corticospinal tract?
Voluntary movements of the body via upper motor neuron moderation.
Where are the cell bodies of the upper motor neurons of the corticospinal tract?
Ventral horn of spinal cord
What is the function of the extrapyramidal descending tracts? Can you name them?
Involuntary muscle tone Vestibulospinal Reticulospinal Rubrospinal Tectospinal
What is the name of the white matter tract that the descending tracts pass through before they reach the medulla? Why is it clinically important?
Internal capsule
Particularly susceptible to haemorrhagic stroke
What is the function of the corticobulbar tract?
Voluntary movements of the head and neck via upper motor neuron moderation.
Where does the corticobulbar tract decussate? What is special about the way it decussates?
Medulla
It is mostly bilateral except contralateral in the lower face, and the tongue (where it synapses with the facial and hypoglossal nerves)
Where does the corticospinal tract decussate?
Lateral tract (most) - medullary pyramids Anterior (some lastminute.com ) - spinal cord
What is a Monosynaptic reflex arc? Give an example
Signal straight from a first order sensory neuron which detects stretch in a muscle to a lower motor neuron which contracts the muscle.
Stretch reflex
What is a polysynaptic reflex arc? Give an example.
A reflex signal that is sent via an interneuron.
Withdrawal reflex in response to pain or the antagonist inhibition arc that pairs with any reflex.
What are the 5 components of a reflex?
- Receptor
- Afferent nerve
- Integrating centre
- Efferent nerve
- Effector organ
Where does a 1st order sensory neuron synapse? (Four places)
2nd order sensory in dorsal column (nucleus gracilis/cuneatus)
2nd order sensory in spinothalamic tract (dorsal horn)
Lower motor neuron for monosynaptic reflex arc
Interneuron for polysynaptic reflex arc
How does an upper motor neuron control movement of the muscles? What is the exception?
Through inhibiting the lower motor neuron which is constantly excited by reflex action.
Except in the hands where there is also ability to excite the lower motor neurons which allows for increased dexterity.
Give four key signs of upper motor neuron injury.
Hyperreflexia
Hypertonia/ spastic weakness
Clonus (muscle spasm following stretch)
Babinski’s sign (foot scrape, toe flare)
Give 3 key signs of lower motor neuron injury.
Hyporeflexia
Hypotonia / flaccid weakness
Fasciculations
What causes clonus?
Stretch reflex stimulated in the ankle.
Upper motor neuron injured so unable to inhibit the reflex.
Results in spasm due to the differing lengths of time for the monosynaptic reflex and the polysynaptic antagonist muscle reflex to reach the muscles.
How would you distinguish between visceral and somatic pain in a history?
Somatic - sharp, stabbing, burning. Can be pinpointed.
Visceral - dull, aching, hard to pinpoint
Why might you ‘see Stars’ if punched in the eye?
Receptors for vision (like all receptors) are modality specific only to a point. If overwhelmed by input, they can be forced to fire by touch/pain sensation.
Where are most sensory receptors located? What implication does this have for burns?
In the dermis
Loss of sensation occurs only in full thickness burns
Why can’t you feel your clothes on your skin unless you attend to them?
Phasic receptors rapidly adapt to a constant stimulus. They fire when there is a change to the stimulus.
Opposite is tonic receptors which fire continuously throughout stimulus
Where on your body is there most sensory acuity? Where is it the weakest? How can it be measured?
Fingertips and lips vs Trunk
2 point discrimination with a paper clip
What causes an increase in sensory acuity in different areas of the body?
Smaller receptive fields, increased lateral inhibition
What causes an increase in motor dexterity in different areas of the body?
Smaller motor units
What causes shingles? What are the symptoms?
Dormant herpes zoster (chicken pox) in the dorsal root ganglion re emerges.
Pain - burning
Rash - scaly
Parasthesia
All restricted to a dermatome
What is meant by orderly recruitment of motor units? Give two reasons that it is beneficial.
Motor units are recruited in order of increasing size so that when only a small force is required, the small ones are activated. As a bigger force is required, more and more bigger units are activated.
- Prevents fatigue by saving the big fatiguable units till needed.
- Permits fine control by only using small units with small forces.
Give 5 extrapyramidal signs. Damage to which structure would cause these?
Pseudoparkinsonism - tremor, bradykinesia, masked facies, shuffling gait
Tardive dyskinesia - jerky ticks
Basal ganglia
Give 2 cerebellar signs.
Ataxia
Intention tremor
What are the 5 cardinal features of Parkinson’s disease?
Pill rolling tremor Shuffling (festinating gait) Masked facies Cog wheel rigidity Bradykinesia
Name 5 diseases/disorders which might cause lower motor neuron signs.
Trauma Primary myopathy - eg muscular dystrophy Guillain Barre Polio Myasthenia gravis
Name 5 diseases/disorders which might cause upper motor neuron signs.
Motor neuron disease - upper and lower Multiple sclerosis Parkinson's Huntington's Stroke
What are the functions of the basal ganglia in motor control?
Decision to move
Direction of movement
Magnitude of movement
Facial expression
What is the difference between alpha and gamma motor neurons?
Alpha cause the contraction of the muscle
Gamma control the size of the muscle spindle receptor so that it remains at the right length to detect stretch. This maintains tone and readiness for action.
What causes Parkinson’s ?
Degeneration of the dopaminergic neurons in the direct nigrostriatal pathway.
Leads to extrapyramidal signs.
What causes Huntington’s?
Degeneration of the GABA neurons in the indirect nigrostriatal pathway. Leads to specific extrapyramidal signs.
What causes multiple sclerosis?
Autoimmune demyelination of the axons in both upper and lower motor neurons. Sensation is unaffected.
What causes polio?
Viral infection that causes irreversible demyelination of the lower motor neuron and loss of movement. Sensation is unaffected.
What is Guillain Barre syndrome?
Rapid onset autoimmune destruction of lower motor neurons which is triggered by - previous infection.
What are the key symptoms of Huntingtons?
Chorea - continuous muscle twitching
Mood and behavioural change
Why can’t you give L-Dopa for Huntingtons? Why does it eventually stop working in Parkinson’s?
Huntingtons affects the GABA neurons in the nigrostriatal pathway so extra dopamine will have no effect
In Parkinson’s extra dopamine will help for a while until there is so much degeneration that there are not enough neurons to cope with the extra neurotransmitter.
When an tissue damage occurs, what substances are released to stimulate pain fibres?
Prostaglandins, K+, bradykinin
How does a nociceptor respond to prostaglandins, bradykinin etc?
Action potential along pain fibres (A delta and C)
Also releases substance P which stimulates mast cells to release histamine
Which nerve fibre types are associated with pain?
A delta
C
Name the nerve fibre types present in a mixed nerve in order of sensitivity. Also give their function.
A alpha - motor A beta - proprioception A gamma - pressure A delta - pain B - autonomic C - pain
In carpal tunnel syndrome, why is motor function lost first, then numbness and tingling before pain?
Function lost in order of the sensitivity of fibre types. From A alpha down to C fibres.
What makes A fibres more sensitive than C fibres?
Larger diameter
Myelinated
What is the cause of referred pain?
Visceral sensory fibres synapse with the same 2nd order neuron as a set of somatic fibres in the dorsal horn. The pain is interpreted as coming from that somatic dermatome.
Where precisely do nociceptive fibres synapse onto second order neurons in the spinothalamic tract?
Laminae 1, 2 and 5 of the dorsal horn
What is lamina 2 of the dorsal horn otherwise known as?
Substantia gelatinosa
Which lamina in the dorsal horn modulates pain signals by inhibiting the others?
Lamina 2 - substantia gelatinosa
Where do opioids act?
Opioid (mu) receptors in the substantia gelatinosa as well as many other areas in the nervous system.
Stimulate the substantia gelatinosa to dampen pain signals.
Give 2 natural opioids and 2 drug opioids. Can you think of an antagonist for these drugs?
Natural - endorphins, enkephalins
Drugs - morphine, codeine
Antagonist - naloxone
Why does rubbing a pain and taking a hot bath ease it?
Thermoreceptors and mechanoreceptors stimulate the substantia gelatinosa to inhibit pain signals
What is hyperalgesia?
An increased sensation of pain to a mild pain stimulus.
Hypersensitivity.
What is allodynia? Can you give an example?
A sensation of pain from something that is not normally painful.
Thigh pain in an arthritic knee
What is the cause of wind-up in chronic pain?
Persistent activation leads to up regulation and an increase in number of receptors at the synapse. This causes an increase in sensitivity and a larger receptive field.
What is neuropathic pain described as?
Burning, tingling, parasthesia, shooting
What is the cause of phantom limb pain?
Cortical remodelling
Where do most strokes occur and why?
Middle cerebral artery because there is a lack of collateral supply
What is a stroke? How is it different from a TIA?
Abrupt loss of focal function from infarct or haemorrhage.
TIA is over in 24 hours. Stroke symptoms last over 24 hours.
What is the pathophysiology of a haemorrhagic transformation infarct stroke?
Infarct - inflammation - oedema - burst vessel - bleed
Stroke with both infarct and haemorrhagic features.
Name 4 modifiable risk factors for stroke.
Smoking /Alcohol
Hypertension
Hyperglycaemia
Atherosclerosis
Name 4 non modifiable risk factors for stroke
Age
Aneurysm
Blood disorder
Cardiac - Atrial fibrillation, Patent foramen ovale
What signs suggest a stroke is haemorrhagic rather than an infarct?
Raised intracranial pressure (vomiting, drowsy, headache)
Raised INR
Patient on warfarin or has blood disorder
Young patient
Head CT - midline shift and white blood
How do you differentiate between a stroke on the dominant and non dominant sides?
Dominant - dysgraphia, dyslexia, dysphasia
Non dominant - complete visuospatial neglect
What are the symptoms of a frontal lobe stroke?
Motor deficit
Personality change
Brocas non fluent aphasia
What are the symptoms of a parietal lobe stroke?
Dominant neglect
Sensory deficits
What are the symptoms of a temporal lobe stroke?
Auditory deficits
Memory problems
Wernickes fluent aphasia
What are the symptoms of a POCS stroke?
Posterior circulation
Occipital/cerebellar signs - Visual disturbance, balance, coordination, cranial nerve nuclei.
What are the symptoms of a TACS stroke?
Total anterior circulation
(Proximal MCA or ICA)
Hemiparesis
Hemianopia
Other cerebral dysfunction according to lobe
What are the symptoms of a PACS stroke?
Partial anterior circulation
(MCA)
2 of 3
Hemiparesis
Hemianopia
Cerebral dysfunction
What are the symptoms of a LACS stroke?
Lacunar
(Single perforating artery)
Silent
Why is it important to order an ecg for a suspected stroke?
Find out if cardiac problems eg af which highly increase the likelihood of a repeat.
Why is it important to test the bm of a suspected stroke?
Hypoglycaemic attack is a huge differential
In ageing which sound frequencies are lost first?
High frequencies
What is meant by tonotopy in the ear?
Describes the mechanical tuning of the ear to different frequencies. The position along the basement membrane of the cochlea determines the resonant frequency.
The hair cells along the membrane therefore respond more readily to different frequencies.
Describe the detection of sound in the cochlea on a molecular level.
Stereo cilia bend. K channels open - depolarise the cell due to abnormal gradient (endolymph has high k). Ca channels open. Neurotransmitter release to spiral ganglia.
What features of an action potential along auditory neurons determine the volume of the sound.
Frequency of action potentials
Size of action potentials due to recruitment of nearby fibres.
Describe the auditory pathway.
Outer hair cells - inner hair cells - spiral ganglion - superior olivary - inferior colliculis - medial geniculate nucleus of thalamus - auditory cortex in temporal lobe
What are the results of rinne and webers test in conductive hearing loss?
Weber - louder on damaged side
Rinne - negative (abnormal) louder through mastoid process
What are the results of rinne and webers test in sensorineural hearing loss?
Weber - louder on opposite side
Rinne - positive test - or appears normal because complete deafness.
What is meant by a positive rinne test?
Normal result. (Opposite to every other test!!!)
What type of bleed from which vessel usually causes a subarachnoid haematoma?
Arterial from a burst aneurysm
Give some potential causes of fitting.
Brain disease - stroke, space occupying lesion
Metabolic - hypoglycaemia, low ca, low Na, high urea
Infection - febrile convulsions
Drug induced
Idiosyncratic- (>2 epilepsy)
What is status epilepticus? Why is it an emergency?
Fitting for over 30mins or a cluster of fits with no recovery
Increases metabolic demand of the brain - brain damage or death
What is a partial seizure? Does a patient lose consciousness?
Partial = focal
Symptoms reflect area which is overactive. Eg motor, aura, Jamais/déjà vu.
Simple - conscious
Complex - loss of consciousness
What is a generalised seizure? Does the patient lose consciousness?
Spread throughout the brain with a loss of consciousness
Can include tonic clonic as well as absence seizures
What are cortical association areas?
Areas in the cortex where information from different modalities is brought together for processing
Which cortical functions are lateralised to the left hemisphere?
Language
Logic
Maths
Motor skills
Which cortical functions are lateralised to the right hemisphere?
Emotional processing
Visuospatial
Art
Music
Which hemisphere is dominant in 95% of people?
Left
Describe the neural pathway of speaking a written word.
Primary visual cortex Angular gyrus Wernickes area Arcuate fasciculus Broca's area Motor cortex
Describe the neural pathway of speaking a heard word.
Primary auditory cortex Wernickes area Arcuate fasciculus Broca's area Motor cortex
What is the proper name for an expressive, non- fluent aphasia?
Broca’s
Can’t get words out but full understanding and can comply with complex commands
What is the name for a receptive, fluent aphasia?
Wernickes
Non sensical fluent speech. Can’t comply with complex commands.
What is long term potentiation? Which neurotransmitter is involved?
Description of memory formation
Hippocampus signals for NMDA glutamate receptors to upregulate synapses and neurotransmitter release.
What factors can increase the likelihood of a memory making it to the long term?
Rehearsal
Emotion
Association
What is anterograde amnesia? What brain lesion is it associated with?
Failure to form new memories
Hippocampus
What is retrograde amnesia? What brain lesion is it associated with?
Can’t retrieve old memories
Global atrophy eg Alzheimer’s
What brain pathway controls wakefulness? What occurs when it is active? What happens when it is quiet?
Ascending reticular activating system (ARAS)
Activated - awake or rem sleep
Quiet - slow wave, deep sleep
What sleep difficulties are associated with anxiety? How is this different from depression?
Anxiety - difficult getting to sleep
Depression - waking in the night then difficult getting back to sleep
What biological functions occur during deep slow wave sleep?
Rest
Decrease basal metabolic rate
Endocrine secretion
What biological functions occur during rem sleep?
Memory formation without emotion
Raised basal metabolic rate
Which neurotransmitter remains active during rem sleep?
Ach
Give three types of tremor and their associated disorder.
Pill rolling at rest - Parkinson’s
Intention - cerebellar damage
Idiopathic
What is the difference between communicating and non- communicating hydrocephalus?
Communicating -
Flow of CSF is uninterrupted. Build up is due to problem with the arachnoid villi
Non- communicating-
Flow is blocked. Most commonly at narrowest point which is cerebral aqueduct.
If there is an infection of the spinal cord, where will pus collect?
Posterior mediastinum
The prevertebral fascia is the compartment that contains the spinal cord and it extends this far, through the retropharyngeal space
Which motor neurons are most important for eliciting motor tone?
Gamma because they are small so have a low threshold for action potential. So constant activity.
Which type of motor neurones are most important for eliciting action?
Alpha.
The big chunky myelinated ones.
What are the signs of multiple sclerosis?
Upper motor neuron signs and sensory signs.
But no lower motor neuron signs
What are the signs of motor neuron disease?
Upper and lower motor neuron mix.
No sensory signs.
