Tandem gait performance in essential tremor: clinical correlates and association with midline tremors.

Program in Physical Therapy, Department ofRehabilitation Medicine, College Physicians and Surgeons,Columbia University, New York, New York, USAAbstract: Gait difÞculty has been reported in essential tremor(ET) although it has been the subject of a limited numberof studies. We broadly assessed these clinical correlates,including the association of gait difÞculty with a variety ofmidline tremors (jaw, voice, neck). Tandem gait (10 steps) wasassessed in 122 ET cases. Cranial tremor score (0Ð3) was thenumber of locations (neck, jaw, voice) in which tremor waspresent. Number of tandem mis-steps positively correlatedwith age (P < 0.001), age of tremor onset (P 5 0.001), andpresence of neck (P < 0.001), jaw (P 5 0.001), and voicetremors (P 5 0.047). Number of tandem mis-steps increasedmarkedly with cranial tremor score: 0 (0.8 6 1.2), 1 (1.1 61.6), 2 (2.3 6 3.0), 3 (3.7 6 1.6) (P < 0.001). It was not corre-lated with severity of arm or leg tremors. ET patients with cra-nial tremors (neck, jaw, voice), those with older age of onset,and those of current older age are more likely to manifest tan-dem gait difÞculty. Tandem gait difÞculty was not correlatedwith severity of limb tremors. Tandem gait difÞculty and cra-nial tremors in ET may both be symptomatic of the sameunderlying pathophysiology, a disturbance of cerebellar regula-tion of the midline, which is distinct from its regulation of thelimbs. ! 2010 Movement Disorder SocietyKey words: essential tremor; clinical correlate; gait; bal-ance; ataxia; cerebellum; head tremor