Bell's palsy

Question 1

Bells palsy: RFs, features, management, f/u and prognosis

Answer 1

Facial nerve paralysis - motor
RFs: 20-40y, pregnancy

Possible cause: HSV

Features:; unilateral (if bilateral needs urgent ENT referral)
- lower motor neuron facial nerve palsy - affectrs forehead (UMN spares upper face)
- post-auricular pain
- altered taste anterior 2/3 tongue
- dry eyes
**- hyperacusis ** - palsy of stapedius muscle, can’t dampen sound

Management:
1) Prednisolone within 72h of onset - 25mg BD for 10 days or 60mg OD for 5 days followed by daily reduction of 10mg (total - 10 days treatment)
2) Antivirals alone not recommended, may consider with specialist advice if severe
3) Eye care to prevent exposure keratopathy - artificial tears and lubricants and tape eye closed at night
4) **If recurrent - urgent ENT referral **

Follow-up:
- if no improvement in 3 weeks - urgent ENT referral
- if long standing weakness for several months - plastic surgery referral

Prognosis:
- most recover fullly within 3-4 months
- if untreataed 15% will have permanent moderate-severe weakness

Referral:
1) Urgent ENT if bilateral or recurrent or paralysis not improving at 3 weeks
2) Opthalmology if cornea remains exposed after attempting to close eyelid

If sensory and motor loss = facial nerve compression eg. parotid tumour or acoustic neuroma

Question 2

Stongest risk factor for Bell’s Palsy

Answer 2

3x more likely in pregnancy

Question 3

Guillain-Barre Syndrome

Answer 3

Immune mediated demyelination of peripheral nervous system triggered by infection (campylobacter jejuni)

Antu-GMI abs in 25%

Rapidly progresive symmetrical weakness of limbs - ascending

Reduced power, normal/mild sensory loss, reduced/absent reflexes

Additional symptoms: respiraotry muscle weakness, diplopia, BL facial nerve palsy, oropharyngeal weakness, urinary retention, diarrrhoea

Investigations:
1) Lumbar puncture - raised protein, normal WCC
2) Nerve conduction studies - redcued motor conduction

Question 4

Miller-Fisher syndrome

Answer 4

Variant of GBS

Ophthalmoplegia, areflexia, ataxia

Eyes affected first

Descending paralysis (rather than ascending in other GBS)

Anti-GQ1b abs in 90%

Question 5

Charcot-Marie Tooth

Answer 5

Most common hereditary peripheral neuropathy

Features:
1) History of frequently sprained ankles
2) Foot drop
3) High-arched feet - pes cavus
4) Hammer toes
5) Distal muscle weakness
6) Distal muscle atrophy
7) Hyporeflexia
8) Stork leg deformity

No cure - focus on physio and OT

Question 6

Drugs that can cause peripheral neuropathy

Answer 6

1) Amiodarone
2) Isoniazid
3) Vincristine
4) Nitrofurantoin
5) Metronidazole

Question 7

Neuropathic pain

Answer 7

DM neuropathy, post-herpetic neuralgia, trigeminak neuralgia, prolapsed disc

1st line: amitriptyline, duloxetine, gabapentin, pregabalin - all as monotherapy

Rescue therapy: tramadol

Localised neuropathic pain eg. post-hereptic neuralgia - topical capsaicin