The gait disorder of advanced essential tremor

Gait disturbances of patients with essential tremor (ET) have been describe d anecdotally, but have never been investigated quantitatively. Recent stud ies provided evidence for a cerebellar-like hand tremor in some patients wi th ET. Therefore, we designed a study to assess cerebellar-like abnormaliti es of leg function. Twenty-five patients with ET, eight patients with cereb ellar diseases (CD) and 21 age-matched healthy subjects were studied for th eir normal and tandem gait using a three-dimensional gait analysis system. During normal walking, CD and ET patients showed only slight abnormalities. However, ET patients exhibited abnormalities in tandem gait with an increa sed number of mis-steps and a broad-based, ataxic and dysmetric gait which was indistinguishable from the findings in CD. When ET patients were separa ted into groups of those with or without intention tremor of the hands, the gait disorder was found to be much more pronounced in the intention tremor group. Patients with this gait disorder were more severely disturbed in th eir activities of daily living, and suffer from an advanced stage of ET. Th e present results quantitatively describe a gait disturbance in advanced ET which affects tandem gait, but leaves normal gait almost unaffected. This is strong evidence for a cerebellar-like disturbance in ET.