The patient, a man in his early sixties, had been diagnosed as suffering from diabetes, hypertension and chronic renal failure. The notes in the patient's case record had however failed to record something that was very obvious. He had bilateral blepharospasm and used his hand to keep his eyes open when talking to me. He told me that he had seen a couple of doctors in various parts of the country for this disorder but nothing had helped. I listened sympathetically and, after the usual review of his various medical problems, prescribed him treatment for diabetes, hypertension and renal failure.
Later, I read an article on benign essential blepharospasm.
I realised that this condition, which was initially considered a psychiatric disorder, is now regarded as a form of focal dystonia affecting the orbicularis oculi and other muscles around the eyeball. No one knows where exactly the lesion is but it is generally regarded as a disorder of neural circuits that regulate blinking. The sensory component of this circuit is triggered by a variety of stimuli ranging from light, sensory stimuli from the trigeminal nerve, and strong emotions. The motor component is mediated by the facial nerve. Blepharospasm disappears when the patient is asleep and when deeply relaxed. Hence, there have been treatments designed to promote such relaxation using pharmacological and non-pharmacological methods. The results have been variable and no one method has been shown to be consistently better. Currently, the most effective treatment for benign essential blepharospasm is injection of Botox into the muscles around the eye. Botox is Botulinum A toxin. It inhibits the release of acetylcholine from presynaptic nerve terminals. The effect Botox injections can last from one to five months.
Ref: Medscape article
