Coexistent blepharospasm and hemifacial spasm: overlapping pathophysiologic mechanism?

BACKGROUND/AIM: Blepharospasm (BEB) and hemifacial spasm (HFS) appear to be distinct disorders. Clinical characteristics of coexistent BEB and HFS have not been examined. The aim of this study was to determine the prevalence, clinical, and imaging features of coexistent BEB among a cohort of HFS patients and controls. RESULTS: Among 665 study subjects, nine (5.5%) of the 164 consecutive HFS patients had coexistent BEB, significantly higher than age and gender matched controls (0/501, 0%) without neurological diseases (p<0.0001). The mean age of the nine patients was 61.4 (SD 9.9) (range 51-72), consisting of 88.9% women, and 66.7% had left sided HFS, similar to HFS patients without BEB. Six (66.7%) reported BEB symptoms at a mean of 0.8 years after HFS onset, one before, and onset was undetermined in two patients. Advanced magnetic resonance imaging and angiography revealed neurovascular compression of the ipsilateral side of HFS, without any basal ganglia lesions. CONCLUSIONS: BEB occurred more frequently in HFS patients, suggesting changes in the brainstem blink reflex circuitry could play a modulatory role in certain at-risk individuals resulting in the coexistence of these movement disorders.