Secondary blepharospasm associated with structural lesions of the brain

Blepharospasm is a form of focal dystonia that manifests as repetitive involuntary closure of the eyes. The pathogenesis of blepharospasm and the neuroanatomic substrates involved are not fully understood. Dysfunction of the basal ganglia traditionally is presumed to be the main cause of most forms of dystonia, but a growing body of evidence suggests that a network of additional cortical and subcortical structures may be involved.

The medical records of 1114 patients with blepharospasm seen over past 10 years at Emory University were reviewed to identify potentially contributing brain lesions. A systematic review of the published literature was also conducted to identify potentially contributing brain lesions.

Among patients with blepharospasm at Emory University, 18 had focal lesions on imaging studies available for review. The literature review revealed 25 articles describing 30 additional cases of blepharospasm associated with focal lesions. Among all 48 cases, lesions were found in multiple regions including the thalamus (n=12), lower brainstem (n=11), basal ganglia (n=9), cerebellum (n=9), midbrain (n=7), and cortex (n=1).

These data in combination with functional imaging studies of primary blepharospasm support a model in which a network of different regions plays a role in the pathogenesis of blepharospasm.