Tremor in hemifacial spasm patients.

Tremor often accompanies dystonia and some other movement disorders. There are no reports describing tremor in patients with hemifacial spasm (HFS). The aim of the study was to assess the occurrence, type and parameters of tremor in HFS patients. The study included 47 HFS patients (mean age: 58.6 ± 10.7-years-old) and 48 healthy volunteers matched by sex and age. Tremor was assessed clinically and objectively using a triaxial accelerometer and EMG. A load test with 500 g weight was performed in order to identify physiological tremor. The Clinical Global Impression-Severity scale (CGI-S) was used to assess the severity of HFS. Neurological examination revealed tremor in 19 patients and 5 control subjects, and the objective methods postural and kinetic hand tremor was confirmed. Among the patients we identified: one case of psychogenic tremor, two patients were diagnosed with essential tremor, six patients had essential tremor in one hand and enhanced physiologic tremor in the other, seven patients had essential tremor in both hands and three patients had physiological tremor in both hands. Five control subjects revealed enhanced the physiological tremor type. The occurrence of hand tremor was associated with higher severity of HFS, as assessed by CGI score. Tremor accompanies HFS in 40% of cases and 10% of control subjects. The aetiology of hand tremor in patients with HFS is unknown. However, it may be associated with compression of the tremor oscillator located in the medulla.