Blepharospasm

Differentiate essential blepharospasm with secondary blepharospasm due to

• Blepharitis
• Trichiasis
• Dry eyes
• Chronic lid or ocular surface disease
• Glaucoma
• Uveitis

Causes of apraxia of eyelid opening

• Parkinson’s
• Progressive supranuclear palsy (secondary parkinsonism syndromes)
• Huntington's disease

Benign essential blepharospasm

Clinical features

• Bilateral involuntary lid closure (although may be asymmetrical)
• Increased frequency of blinking
• Remainder of face not involved
• Relieved by relaxation/distraction
• Not present during sleep

Management

• Botox injection to lids: very effective in the short term
  • Botulinum toxin A prevents the release of acetylcholine from the presynaptic neuron into the neuromuscular junction
• Management of primary causes (see above)

Meige syndrome

• Blepharospasm with lower facial involvement
• Spastic contractions of lower facial muscles (facial dystonia)
• Unknown cause
• Treatment: botox injection

Hemifacial spasm

• Unilateral tonic-clonic blepharospasm and facial dystonia
• Indicative of a compressive lesion irritating the VII nerve: typically a ectatic vertebral artery or anterior inferior cerebellar artery
  • Compression is at the nerve root’s exit at the level of the brainstem
• Typically persists while asleep
• Imaging required to exclude tumour (eg. pontine glioma and cerebellopontine angle)
• Management: botox injections or surgery