Blepharospasm-oromandibular dystonia syndrome (Meige's syndrome): clinical aspects.

Meige's syndrome is a form of cranial dystonia characterized by the presence of bilateral dystonic spasms of the facial muscles and frequently of other cranial muscles as well. Its most common and disabling manifestation is blepharospasm which can render the patient functionally blind. Several types of orbicularis oculi spasms occur in Meige's syndrome: brief clonic spasms, prolonged dystonic spasms, constant tonic contraction, and "apraxia" of lid opening. In the completed form of the syndrome, blepharospasm is typically associated with lower facial or oromandibular dystonia. Spasms of the neck and limb muscles, generally mild, and action tremor not uncommonly accompany the cranial dystonia. In most patients the cause of the spasms is unknown. This so-called idiopathic or primary form of Meige's syndrome is considered an adult form of adult onset dystonia. Secondary Meige's syndrome can be encountered in the context of several neurodegenerative disorders, chronic administration of neuroleptics, levodopa, or other drugs, and in patients with focal brain lesions. These secondary cases of Meige's syndrome suggest that a dysfunction of the basal ganglia or of the mesencephalic/diencephalic region plays an important role in the pathophysiology of this dystonic syndrome. Recent neurophysiologic studies and postmortem findings in some patients also support the notion that disease of the brain stem contributes to the pathophysiology of orofacial dystonia.