Neurology IM Flashcards
Definition of epilepsy?
Chronic neurologic disorder with predisposition to seizures and defined by one of:
1. Two or more unprovoked or reflex seizures separated by over 24 hrs
2. One unprovoked or reflex seizure in individual with high risk of subsequent seizures
3. Diagnosis of an epilepsy syndrome
Causes of central vertigo?
Main concern is Posterior Circulation Stroke.
Causes of peripheral vertigo?
Benign Paroxysmal Positional Vertigo (main)
Vestibular Neuritis (main)
Ramsay-Hunt Syndrome
Drugs (Gentamicin, cisplastin)
Labyrinthine trauma
How to differentiate Central vs Peripheral vertigo with an exam?
HINTS EXAM!!!
Central = all 3 components reassuring
Peripheral = Any 1 component worrying
Head Impulse, Nystagmus and Test of Skew (HINTS)
Central vs Peripheral vertigo clinically?
Vertigo lasts hours in Stroke Central Vertigo, but shorter durations do not rule out TIA.
Central = not a/w head movement.
Peripheral = a/w head movement.
Central = Neurological deficit
Peripheral = No neurological deficit
What is miller fisher syndrome?
Rare variant of GBS.
Triad of ataxia, areflexia, ophthalmoplegia
Causes bilateral eye and muscle weakness + cerebellar gait issues.
Start in legs, slowly spread to arms and face
Presence of Ab to GQ1b in 90%
What is inverted supinator reflex? Associated with?
When supinator reflex elicits finger flexion instead of elbow flexion.
Indicates lesion at C5 or C6
Causes of peripheral neuropathies?
Diabetes
B12 deficiency
Guillaine-Barre
Iatrogenic
Types of mononeuropathies?
Median neuropathy (CTS)
Ulnar nerve palsy
Radial nerve palsy
Common peroneal palsy
Facial palsy
3rd CN palsy
Lateral femoral cutaneous palsy
Lateral femoral cutaneous nerve palsy also known as meralgia paraesthetica
What is Chronic Inflammatory Demyelinating Polyneuropathy?
Progress of symptoms beyond 6 wks or relapsing-remitting in nature
Often has generalized hyporeflexia and symmetrical, proximal and distal pattern of weakness and some distal sensory involvement
Types of Multiple Mononeuropathies?
Vasculitic neuropathies
Multiple entrapments
Amyloid
Sarcoidosis
Lyme disease
Lymphomatous or carcinomatous infiltration
How does vasculitis neuropathy present?
Classical acute/subacute onset of mononeuritis multiplex
Distal sensorimotor axonal peripheral neuropathy
Radicular / plexus pattern
Mononeuritis multiplex happens when there is damage to at least 2 different areas of PNS. Causes tingling, numbnes, pain, paralysis etc.
What is mononeuritis multiplex?
when there is damage to at least 2 different areas of PNS.
Causes tingling, numbnes, pain, paralysis etc.
Clinical features of Myasthenia Gravis?
Flucutating weakness, abnormal fatigue that improves with rest
Weakness can affect extraocular, bulbar or proximal limb muscles
Ocular = asymmetrical ptosis, extraocular eye movement limitation
Bulbar weakness = difficulty swallowing, chewing, speaking
Limb weakness = usu symmetrical and proximal
Can cause neck weakness or head drop
MG crisis = respi muscle weeakness causing ventilatory failure
Deep tendon reflexes usu preserved
4 subtypes of stroke?
Cryptogenic 40%
Large artery atherosclerosis 15-40%
Small vessel occlusion/Lacunae 15-30%
Cardioembolic 15-30%
Why cant u give heparin/warfarin after stroke?
BBB is compromised right after stroke. So blood can enter brain after stroke (haemorrhage), killing them
Research showed LWMH raises risk of ICH
Which spinal tracts can hypothalamic infarct affect?
DCML and corticospinal tract decussates NEAR the thalamus.
Hence can have hemiparesis in some parts.
Management of postural hypotension after excluding all causes (even ANS)?
Give Fluorocortisone + Midodrine. Fluorocortisone is a mineralocorticoid with water-retention effect. Hence watch out for metabolic alkalosis and supine HTN. Midodrine is an alpha-adrenergic agonist, causing vasoconstriction.
For non-pharm mx, give abdominal binder, compression stockings, avoid hot showers, avoid big meals. These are all things that can cause peripheral vasoconstriction.
Does body try to recruit collaterals in stroke?
Body often tries to recruit collaterals in stroke, but when this fails then deficits result.
But thats why after a while the stroke can improve cuz collaterals can be recruited.
How does Atrial Fibrillation form clots?
Chaotic contraction. Not all the blood moves out of L heart, with stagnated blood left. This blood just stays there and stagnant. This blood can form clots in ppl with prediposing factors e.g. DM, age, structural disease. Lack of clearance causes blood stasis and clot formation. Left atrial appendage stores all the clots.
Timing for EVT and TPA?
EVT can be done up to 6.5 - 10 hours.
TPA within 4.5hrs
What is pulse deficit, and what is it a characteristic of?
Difference btw pulse rate measured by cardiac auscultation and peripheral pulse rate obtained by palpation. Can hear heartbeat on auscultation, but cannot feel.
Characteristic of AFib!!!
How can motor homunculus help classify stroke location?
It can help classify cortical stroke areas by affected body parts
Causes of delayed pulse?
Dissection. What else?
How to know the lesion type by onset duration?
Slowly progressive onset = slowly growing expansile lesion
With occlusion, onset is always acute
2 determinants of clot formation in heart that can be seen on TTE?
- size of LA (LA diameter) = atrial cardiopathy
- REgional wall motion abnormality = some form of infarction of cardiac tissue causing that area to not move so well - causing dyskinesia of cardiac muscles, causing blood stasis and hence clots.
Hence all conditions that cause blood stasis in heart predisposes to clot formation.
Valvular defects is a diff issue. Its just either too narrow or too lax. But only L heart valvular issues predispose to clot formation, and especially raises risk of clot leaving the heart.
Investigations for stroke?
CT scan!! = can do perfusion scan to check for penumbra. Can also inject dye to check arteriogram.
MRI!!