Ptosis following botulinum toxin injection in hemifacial spasm

Hemifacial spasm (HFS) is characterized by irregular involuntary tonic or clonic contractions of muscles innervated by the seventh cranial nerve. Patients usually need long-term treatment, as spontaneous remission is infrequent. Repeated botulinum toxin injection has been shown as a safe and successful treatment for symptomatic relief in patients with HFS.1 Side effects are usually mild and transient. Ptosis has been reported in about 24% of patients with HFS probably due to diffusion of toxin to levator palpebrae superioris muscle.2 However, the frequency of ptosis in patients with HFS has not been addressed yet, due to causes other than botulinum toxin side effect. Herein, we present a case of HFS who presented to our clinic with complaint of complete ptosis and progressive pain early after botulinum toxin injection. Despite initial negative evaluations, further work up revealed a compressive lesion. A 75-year-old man presented with left severe ptosis since 3 weeks ago (Figure 1). He was known case of left HFS since 4 years ago, and botulinum toxin had been regularly injected for his symptom relief in orbicularis oculi, corrugator, and procerus muscles.   Figure 1. Left Blepharoptosis one week after botulinum toxin injection   The patient stated that this new ptosis had begun within a week after his last Dysport (Ipsen, Ltd., Slough, Berkshire, UK) injection while he had no ptosis in his previous injections. In past medical history, he had ischemic heart disease, hypertension, cataract extraction of both eyes, and glaucoma surgery on his right eye. He had been admitted to the neurology ward of a general hospital.