NEUROLOGY Flashcards
what is Bell’s palsy?
unilateral LOWER motor neuron facial nerve palsy of rapid onset
is the forehead affected in Bell’s palsy? what does this help differentiate it from?
YES
stroke commonly leaves the forehead spared (UMN lesion rather than LMN)
what causes Bell’s palsy?
unknown - could be from inflammation/infection of facial nerve
RFs for Bell’s palsy
- age 15-45
- diabetes
- immunocompromise
- obese
- HTN
- pregnancy
how does Bell’s palsy present?
- rapid onset (<72h)
- unilateral facial weakness/paralysis e.g. loss of forehead and brow movement, inability to close eyes/drooping eyelids, loss of nasolabial folds and drooping lip
- eye probs e.g. dry, painful, excessive tearing
- numbness/tingling of cheek and mouth
- may have ear pain on affected side
will have no other involvement of the body!!! otherwise healthy
investigations for Bell’s palsy. how is it diagnosed?
physical exam - cranial nerves, parotid gland, skin of head and neck, eyes
routine lab tests/imaging not required in primary care for new-onset Bell’s palsy
diagnosis made when no other condition is found to be causing the sx
management of Bell’s palsy
- IF presenting within 72h, can give prednisolone 50mg OD
- self-limiting, will recover within 2-3w
what is an acoustic neuroma?
which cells/nerve is it associated with?
a benign tumour of the Schwann cells arising from the vestibulocochlear nerve innervating the inner ear
what age patients are normally affected by an acoustic neuroma?
what are 3 risk factors?
40-60 years old
RFs
- ionising radiation to head/neck
- neurofibromatosis type 2 (genetic condition)
- family hx
what type of tumour is an acoustic neuroma?
a cerebellopontine angle tumour (occurs in the posterior fossa)
which nerve can get compressed if an acoustic neuroma grows large enough?
facial nerve
signs and symptoms of an acoustic neuroma
GRADUAL ONSET OF…
1. unilateral sensorineural hearing loss
2. unilateral tinnitus
3. dizziness/imbalance
4. sensation of fullness in ear
IF compresses facial nerve > facial nerve palsy (forehead not spared)
clinical hearing tests for an acoustic neuroma and their results
- Rinne’s - air conduction greater than bone conduction bilaterally
- Weber’s - sound lateralises to unaffected ear
1st line and gold standard investigations for an acoustic neuroma
1st line = audiometry with audiogram
Gold std = MRI head
treatment options for an acoustic neuroma (3)
- conservative + monitoring (if v small, no sx)
- surgery - partial or total removal
- radiotherapy
what pattern of hearing loss will an acoustic neuroma show on an audiogram?
sensorineural hearing loss
what is anterior cord syndrome?
an incomplete spinal cord lesion affecting the anterior 2/3rds of the spine
what can cause ischaemia of the anterior spinal artery, leading to anterior cord syndrome? (think iatrogenic, direct, indirect)
- iatrogenic e.g. cross-clamping of aorta during thoracic/AAA repair
- direct injury/trauma
- crush injury
- burst fracture
- gunshot/knife injury - indirect injury (occlusion/hypoperfrusion of ASA)
- severe hypotension
- atherothrombotic disease
- vasculitis
what causes anterior cord syndrome?
ischaemia within the anterior spinal artery
pathophysiology of anterior cord syndrome…
what tracts are supplied by the ASA?
so what is characteristic of anterior cord syndrome?
- ischaemia within ASA
- ASA supplies blood to anterior 2/3 of spinal cord and to the bilateral SPINOTHALAMIC and CORTICOSPINAL tracts
- these tracts are responsible for pain and temp (spinothalamic) and voluntary movement (corticospinal)
- the dorsal column (fine touch, proprioception, vibration) is spared
so ACS is characterised by a loss of pain and temperature sensation, and loss of motor function
signs and symptoms of anterior cord syndrome
BELOW THE LEVEL OF THE LESION…
1. bilateral loss of pain and temp sensation
2. bilateral loss of motor movement (paralysis)
3. preservation of fine touch, proprioception and vibration
initial and gold std investigations for anterior cord syndrome
initial…
1. bloods - FBC, U&E, clotting, cultures, inflamm markers
- LP and CSF analysis
(to rule out MS, infection or inflamm disease) - echo
(to rule out source of embolism e.g. IE)
GOLD STD…
= MRI
what will be seen on MRI in anterior cord syndrome?
thin, pencil-like hyperintensities of the anterior cord (= ischaemia)
management for anterior cord syndrome
- depends on cause, may need surgery if direct damage or blood thinners e.g. apixaban if atherosclerosis
- MDT including physio
possible causes of secondary epilepsy
- underlying structural lesions - trauma, neoplasms, malformations, stroke
- metabolic - alcohol, electrolyte disorders
- infection e.g. encephalitis
- rare genetic diseases e.g. ion channel mutations
a) what is a partial/focal seizure?
b) what are the two types?
a) a seizure occurring in only one hemisphere/lobe
b) simple partial - pt remains conscious and often remembers
complex partial - pt has impaired/loses consciousness
how does the ICTAL phase of a partial/focal seizure present if the lobe is…
a) temporal
b) frontal
c) parietal
d) occipital
a) think memory, emotion and receptive speech…
auras e.g. deja vu, auditory hallucinations, funny smell
out of body experience e.g. lip smacking, chewing, fiddling
b) think motor and thought processing…
Jacksonian march - seizure marches up/down homonculus starting in face or thumb
c) sensory disturbance e.g. tingling, numbness
d) visual phenomena e.g. spots, lines, flashes
what is a generalised seizure? who does it more commonly affect and what is ALWAYS impaired?
a seizure affecting BOTH hemispheres of the brain, no localising features
more common in children
consciousness always impaired
what are the 6 seizure types?
- tonic - muscles stiff and flexed, often causes fall (back)
- atonic - muscles relaxed and floppy, loss of tone, often causes fall (forwards)
- clonic - violent muscle contractions/convulsions
- tonic-clonic (gran mal) - tonic phase followed by convulsions
- myoclonic - short muscle twitches
- absence - brief, lost and regain conscious temporarily e.g. stopping mid-sentence, zone out then continue
possible preictal signs/symptoms
- lasting hours/days
- may be change in mood/behaviour
- aura e.g. feeling in gut, flashing lights (implies focal e.g. temporal)
general postictal signs/symptoms
- headache
- confusion
- myalgia/sore tongue
focal lobe specific postictal symptoms
a) temporal
b) frontal
c) parietal
d) occipital
a) emotional disturbance, dysphasia, bizarre associations, hallucinations
b) motor features e.g. pedalling legs, motor arrest, dysphasia, speech arrest, postictal Todd’s palsy (paralysis)
c) sensory disturbance e.g. tingling, numbness, pain
d) visual e.g. spots, lines, flashes
investigations following a seizure
- bloods (FBC, U&Es, LFTs, gluocse) - rule out infection, anaemia, electrolyte abnormalities, metabolic probs, hypoglycaemia
- EEG
- MRI
which antiepileptic drug is contraindicated in pregnancy?
sodium valproate
first-line tx for generalised tonic-clonic seizures in:
a) males
b) females
a) sodium valproate
b) lamotrigine or levetiracetam (if not child-bearing age and not likely to need tx when older, consider SV)
first and second line tx for focal seizures
first = lamotrigine or levetiracetam
second = carbamazepine, oxcarbazepine
first line tx for absence seizures
ethosuximide
how is status epilepticus treated?
IV lorazepam
what is an essential tremor? what is it’s heritability pattern?
an autosomal dominant condition affecting both upper limbs
intention vs essential tremor
intention = slower, zig-zag movements evident when intentially moving towards a target e.g. reaching for a mug
essential = bilateral fine tremor without necessarily intentional movement
RFs for an essential tremor (3)
- advancing age
- family hx
- exposure to toxins
signs and symptoms of an essential tremor
a) when does it happen
b) where
c) improves/worsens with what
BILATERAL FINE TREMOR
a) more prominent with voluntary movement e.g. tying shoelaces, but can occur at rest
b) bilaterally in the hands, can also affect head, jaw and vocals
c) improves with alcohol and rest
worsens with stress, fatigue, caffeine and extreme temps
what movement can you ask a pt with an essential tremor to do that will exaggerate their tremor?
worse when patient outstretches arms (called postural tremor)
1st line tx for an essential tremor
what else can you give?
1st line = propranolol
can also give antiepileptic drugs e.g. primidone
where does blood often collect in an EDH? from which artery?
- temporal region
- middle meningeal artery
what is the most common cause of an EDH? who are they common in?
almost always trauma, can be “low-impact” e.g. blow to head or fall
commonly seen in adolescents
what is the classic presentation of a patient with an EDH?
loses consciousness, gains it again and has a LUCID PERIOD, then a second loss of consciousness
signs and symptoms of an EDH
- acute
- headache
- N&V
- drowsy
- rapid neuro deterioration
- hemiparesis
- FIXED DILATED PUPIL
gold std investigation for any haemorrhage
CT head
how will an EDH appear on CT?
- biconvex (lentiform/lemon) hyperdense collection around surface of brain
- limited by suture lines of skull
- may have skull fracture if trauma
definitive tx for an EDH
craniotomy and evacuation of haematoma
other than surgery, how may you manage an EDH?
- IV fluids to maintain circulation/preserve cerebral perfusion
- if raised ICP give IV MANNITOL (osmotic diuretics, reduces cerebral oedema)
what is vasculitis?
inflammation and necrosis of blood vessel walls with subsequent impaired blood flow to end-organs
what is giant cell arteritis (GCA)?
a type of vasculitis affecting medium and large-sized vessel arteries