[Orthostatic tremor]

Orthostatic tremor (TO) is a recently described new type of a high frequency irregular tremor which affects antagonistic sets of muscles in the lower limbs only since the erect posture is maintained. We describe two other cases of this peculiar kind of tremor which may be not so uncommon as up to now realized and emphatize its main diagnostic and semeiological characteristics. TO may share some basic pathophysiological mechanism with tremors of the classical heredofamilial essential variety.