Random Neurology Facts/Questions Flashcards
Differentials for Cerebellopontine angle tumours
Schwannoma (8th»5th), Aneuryms, arachnoid cyst, meningioma, mets, epidermoid, ependymoma (SAME)
Cranial Nerve 1 name, location and function
Olfactory: sense of smell. Extending across inferior frontal lobe. Runs with anterior cerebral artery
Cranial nerve 2 name, location and function
optic, sensory component of vision. located superior to the infundibulum. I.e. the anterior midbrain. Surrounded by anterior communicating artery and opthalmic artery which come from the internal carotid
CN 3name, location and function
Occulomotor, inferior to the mammillary body in the midbrain. Eye movements. Comes out between the posterior cerebral and superior cerebellar arteries. Posterior communicating superior to it
CN 4 name, location and function
Trochlear, junction of midbrain and pons. Superior oblique muscle. I.e. cant go crosseyed Hugged by the Posterior cerebral artery and superior cerebellar artery
CN5 name, location and function
Trigeminal Nerve, Sensory and motor: S:face, sinuses teeth. M: muscles of mastication. 3 branches Opthalmic, mandibular and maxillary. Mandicular is only one with motor component. Appears in the mid pons. Runs out like a chicken foot across the cerebellopontine angle.
Lateral to pontine arteries and inferior to superior cerebellar arteries
CN 6 name, location and function
Abducens: lateral rectus, abduction of the eye. Most anterior of ponto-medullary nerves. Sits superior to the AICA
CN 7 name, location and function
Facial : Muscles of the face. Temporal, Zygomatic, buccal, marginal mandibular, cervical) Exists with the Vestibulocochlear nerve in the mediolateral ponto-meduallar junction. SUperior to lateral AICA
CN 8 name, location and function
Vestibulocochlear Inner ear sensation. Runs with facial nerve in the mediolateral pontomedullary junction. Superiro to lateral AICA
CN 9 name, location and function
Glossopharyngeal Motor and sensory: pharyngeal motor, posterior sensation of tongue and pharynx. Supero-lateral medulla Triangulated by AICA, vertebral artery and posterior inferior cerebellar artery.
CN 10 name, location and function
Vagus Motor and sensory: Motor to heart, lungs, bronchi etc. Sensory to vicera too. Triangulated by AICA, vertebral artery and posterior inferior cerebellar artery.
CN 11 name, location and function
Accessory nerve : Sternocleidomastoid and trapezius muscle. Triangulated by AICA, vertebral artery and posterior inferior cerebellar artery. but then runs paravertebrally
CN 12 name, location and function
Hypoglossal Muscles of the tongue. Branches out from anterior medulla. Triangulated by AICA, vertebral artery and posterior inferior cerebellar artery.
Cranial nerve not named : name, location and function
Intermediate nerve comes out between the 7th and 8th CN and has motor: submaxillary and sublingular gland. Sensory to anterior part of the tongue and soft palate.
Proteins seen in Alzheimers disease
Tau protein and Beta amyloid (42)
Mechanism of action of acetazolamide
Carbonic anhydrase inhibitor: acts on the proximal tubule (essentially creating a T2RTA). As carbonic anhydrase is blocked, sodium is wasted at the expense of holding onto H+. It therefore drops intravasc. pressure: can use in glaucoma and also IIH
Common deficiency seen in MS
Vitamin D
Common deficiency in restless legs syndrome
Iron
Cause of vitamin A def.
Uncommon in the developed world. Only seen really in pancreatic insufficiency
Causes of Vitamin B12 def.
Often seen in those with drug habit, in particular NANGs i.e. Nitrose oxide.
Typical host of werneckies symptoms
B1 is thiamine –> ataxia, opthalmoplegia, nystagmus,
Corticobasilar degeneration typical features
asymetric parkinsons, dystonia, myoclonus, apraxia
Choice of antiepileptic in those who are young, pregnant or have psychiatric issues
Lamotrigine
Treatment for trigeminal neuralgia first line
carbemazepine
Treatment for SUNCT and definition/presentation
Lamotrigine
short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing) is one of the rarest of all primary headache syndromes. It is one of the trigeminal autonomic cephalalgias, along with cluster headache and paroxysmal hemicrania
Trigeminal autonomic cephalalgias and how to differentiate
Cluster headache, SUNCT, paroxysmal hemicrania
Cluster: strictly unilateral, circadian periodicity. 15-90 mins, aggrevated with exercise, alcohol. Treat with O2, subcut sumitriptan, lignocaine topically. Prevent with verapamil
Paroxysmal hermicrania: Unilateral, differs due to the shorter duration and higher frequency. Can be centred retro-orbital or occipital. Typically have 5 daily and up to 40. Usually mechanically triggered i.e. bending over. Treatment is with Indomethocin- aborts universally
SUNCT: MOST brief and MOST frequent 5-250 seconds. Short lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing. Usually opthalmic distribution of trigeminal nerve.
Should have MRI- posterior fossa abnormalities are common. Lamotrigine is the most effective
Cluster headache
Cluster: strictly unilateral, circadian periodicity. 15-90 mins, aggrevated with exercise, alcohol. Treat with O2, subcut sumitriptan, lignocaine topically. Prevent with verapamil
Paroxysmal hemicrania
Paroxysmal hermicrania: Unilateral, differs due to the shorter duration and higher frequency. Can be centred retro-orbital or occipital. Typically have 5 daily and up to 40. Usually mechanically triggered i.e. bending over. Treatment is with Indomethocin- aborts universally
SUNCT
SUNCT: MOST brief and MOST frequent 5-250 seconds. Short lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing. Usually opthalmic distribution of trigeminal nerve.
Should have MRI- posterior fossa abnormalities are common. Lamotrigine is the most effective
Contraindications to acetylcholinesterase inhibitors
LBBB, sick sinus, heart blocks.
Cause of VI CN palsy that would also lead to pachymeningeal enhancement on MRI
Intracranial hypotension
Typical story for vascular cognitive impairment
Increasing impulsivity and also hypomania: eating lots, shouting, sudden emotional change wiht laughing and crying ‘pseudobulbar effect’
side effect of fingolimod
Maccular oedema first dose can cause bradycardia
Immune-mediated necrotising myopathy findings
Necrotising muscle without inflammation.
Anti-3-hydroxy-3-methylglutaryl-coA reductase (anti-HMGCR) and anti-signal recognition particle (anti-SRP) antibodies are crucial for dx.
Stroke: when to initiate anticoagulation in patient with cardioembolic stroke
1-3-6-12 rule. 1 day post TIA, 3 days post small non-disabling stroke, 6 days post moderate and 12 days to 2 weeks post large artery stroke with significant deficit.
Commence aspirin in the interim
Cause of subacute combined degeneration of the cord and associations
Combined degeneration of the cord refers to the dorsal and lateral columns being affected demyelinating. B12 deficiency is common as a cause. Which causes a raised homocystine level and elevated methylmalonic acid (MMA)
Spinal cord components and function
Lateral corticospinal tract: Motor: decussates at medullary pyramids
Posterior column-medial lemniscal pathway: Sensory (Vibration, proprioception, fine touch) - crosses in lower medulla
Anterolateral pathways are sensory - pain, temperature, crude touch - decussate in the spinal cord at anterior commissure
Brown-sequard syndrome
Hemi-cord lesion
Lateral corticospinal tract damage : ipsilateral upper motor neuron weakness
Posterior column: ipsilateral vibration and proprioception loss
Anteriolateral system: contralateral pain and temperature loss
First line management for focal seiures
Lamotrogine: AEs of slow titration and potential for SJS
Sensorimotor symptoms and how to work through them:
Symmetric or asymmetric
Symmetric: distal, proximal or mixed
Proximal = myopathy, ALS or myasthenia
Proximal and distal: with no reflexes = GBS or CIDP
Brisk reflexes: myelopathy
Fluctuating weakness with no sensory deficit = LEMS or myasthenia
Distal Symmetric if pure motor = hereditary syndrome
sensory + motor is typically metabolic, metastatic (paraneoplastic) or toxic
Sensory purely : Diabetes, metabolic, HIV, nutritional, amyloid
Painful small fibre without large fibre = HIV, diabetes, amyloid
Asymmetric: Purely distal motor = ALS, inclusion body myositis or multifocaly motor neuropathy
Motor + sensory
Entrapment, radiculopathy, vasculitis, HNPP, HIV
Proximal + distal with pure sensory = ganglionopathy: paraneoplastic, sjogrens, HIV
Motor + sensory = polyradiculopathy, plexopathy, mononeuritis multiplex
Difference between large and small fibre neuropathy
Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions.
Red flag symptoms for Parkinsons plus: dysautonomia
MSA
Red flag symptoms for Parkinsons plus: Opthalmoiplegia (can’t look up)
PSP
Red flag symptoms for Parkinsons plus: Early cognitive impairment
DLB sometimes PSP or vascular parkinsonism
Red flag symptoms for Parkinsons plus: Visual hallucinations not provoked by meds
DLB
Red flag symptoms for Parkinsons plus: Instability and falls
MSA and PSP (espeically wihtin the first year)
Red flag symptoms for Parkinsons plus: Marked asymmetry
anything but parkinsons
Red flag symptoms for Parkinsons plus: rapid onset and stepwise deterioration
Vascular parkinsonism
Red flag symptoms for Parkinsons plus: lack of response to L dopa
Anything but parkinsons
Sensitivity of CT for SAH
Sensitivity at 12 hours is 95%
PRES definition, causes, treatment
Posterior reversible encephalopathy syndrome (PRES) is a syndrome of ‘cephalgia, convulsions, confusion, and vision loss’ (CCCV) typically in the context of severe hypertension
Severe hypertension, beit from pre-eclampsia or other causes is the driver of pathophysiology
MRI-B classically bilateral hyperintense densities in the parieto-occipital regions on T2 weighted images
Normal opening pressure for LP
10-25 cm
Idiopathic intracranial hypertension
CSF pressure >25 cm - clinical features including increased blind spot with risk factors of being female, obese
Can treat with acetezolamide, but the key is weight loss
MRI findings of non-nodular pachymeningeal enhancement cause
Low pressure - post LP is the most common. Treat with blood patch
Trigeminal neuralgia cause
15% non-vascular or demyelinating, 85% are vascular - typically the superior cerebellar artery loop.
However, in young persons presenting with trigeminal neuralgia, think about MS as it is a common presenting symptom of MS in the under 50 age group.
Carbemazepine MOA
Sodium channel blocker, SE agranulocytosis and hyponatraemia
Treatment trigeminal neuralgia
Carbemazepine: second line gabapentin, baclofen. Can progress to Gamma knife surgery or posterior fossa decompression
Contraindication to triptan use
Hemiplegic migraine or migraine with brainstem aura
I.e. migraine with hard neurological signs or symptoms (Two or more brainstem-related aura symptoms (ie, dysarthria, vertigo, tinnitus, hypacusis, diplopia, ataxia, decreased level of consciousness)
Also contraindicated in uncontrolled HTN or significant vascular disease
Triptans MOA
Selective agonists for 5 hydroxytriptamine receptors (5HT) specifically 1B (reverse intracranial dilatation) and 1D (neuronal inhibition)
Cough headache association
MRI-B will lead to discovery of chiari malformation in 50% of cases
Triggers for draining extradural haemorrhage
> 10mm, GCS <9, Papillary asymmetry, midline shift of 5mm if a chronic bleed
Classification of seizures
Focal/partial or generalised
If focal/partial: with or without impaired awareness
Focal with impaired awareness can then tend to secondary generalised seizure
NOTE: absence seizures are a form of GENERALISED seizure
Most common structural abnormality that leads to seizures
Mesial-temporal sclerosis with associated temporal lobe epilepsy : auram, loss of awareness, staring, behaviour change and amnesia
In patients with concurrent hipocampal atrophy, treatment is particularly difficult
‘generalised spike waves’ on EEG
referring to generalised seizure activity
Mutation associated with MND
SOD1
Glutamate levels increase and are toxic to the neuronal system
Pathological signature of MND
TDP 43 inclusions (not associated with SOD1 strangely)
Split hand syndrome
First dorsal interossei wasting out of proportion to the wasting seen in abductor digiti minimi (i..e rules out ulnar nerve lesion)
Abductor pollicis brevis (thenar eminence) wasting
CADSIL meaning
Cerebral autosomal dominant ateriopathy with subcortical infarcts and elukoencephalopathy: NOCTH3 gene
Migraines in middle age as clue.
B12 deficiency presentation
Also called cobalamin. Elevated MMA and Homocystine. Common in Strict vegetarians or vegans. Sub-acute degeneration of the cord can occur in B12 deficiency. Stores of B12 are 3-5 years
Folate deficiency presentation
Also called vitamine B9. Limited stores of Folate, but seldom def. seen unless alcohol etc.
Part of the brain responsible for hemibalismus
Subthalamic nucleus
Most common imaging finding in someone with focal epilepsy?
Hippocampal sclerosis i.e. mesial temporal sclerosis
Coupling this a history of febrile juvenile seizures is common
Focal epilepsy mannifest which clinical seizure syndrome
Temporal lobe epilepsy
Temporal lobe epilepsy seminology
Aura is common including gustatory. There is often impaired awareness for a short period of time. Repetitive stereotypes movements or automatisms are seen.
Limbic encephalitis associations with cancer
Anti-Hu, which is associated with small-cell carcinoma of the lungs.
Anti-Ma2, associated with germ-cell tumours of the testis.
Anti-NMDAR, associated with tumors of the ovaries, commonly teratomas.
GBS type of nerve fibres affects
Large myelinated fibres
