[Orthostatic tremor as a cause of difficulty in standing still].

Orthostatic tremor is characterized by a fine tremor of lower limb muscles that produces instability while standing still and alleviates on walking or sitting. We report two patients, aged 54 and 72 years old, in whom the tremor caused falls. The clinical features, a negative neurological examination, the alleviation on walking or sitting and the good response to clonazepam allowed the diagnosis. This disease should be considered in the differential diagnosis of standing still instability.