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
SENSORINEURAL LOSS
1. Rinne’s - air conduction greater than bone conduction bilaterally
2. 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