Benign essential blepharospasm: The hallmark is that it affects both eyes.
Meige syndrome: When blepharospasm affects the lower face, it can be difficult to differentiate from bilateral blepharospasm.
Aberrant regeneration following facial nerve palsy, with a history of Bell palsy or trauma, creates a clinical condition that is similar to hemifacial spasm and is treated similarly.
Parkinson disease can be associated with unilateral apraxia of lid opening, which can appear similar to hemifacial spasm.
Orbicularis myokymia affects only the eye, is usually self-limiting, and is believed to be caused by a number of factors including
- Caffeine
- Stress
- Physical exertion
- Fatigue
Corneal irritation can cause voluntary and/or involuntary contraction of the orbicularis muscle, which can rarely be unilateral and can rarely include the lower face.
Facial tics can be unilateral and can mimic hemifacial spasm but do not respond as well to botulinum injections.