[Primary orthostatic tremor: report of 4 cases].

We report on four cases of primary orthostatic tremor. The purpose of this study is the rarity of this type of tremor and the differential diagnosis with other tremors. The electrophysiological study showed a 15-20 Hz tremor frequency in our cases. There are clinical, electrophysiological and therapeutic differences of primary orthostatic tremor in report to other tremors of legs, according to the literature and characteristics of our cases.