Dysphagia as a side effect of botulinum toxin injection.

Dysphagia is a known adverse effect of botulinum toxin injection into the cervical region for dystonia. We present an unusual case of dysphagia arising from injection into the orbicularis oculi muscle, which has hitherto not been described. We postulate that her dysphagia was caused by distant side effects of botulinum toxin due to repeated injections. We recommend that clinicians should restrict the frequency of injections to as few life-time doses of the toxin as possible for adequate management of spasm. The practice of re-injecting patients routinely every three months, or at the first return of mild spasms should be discouraged.