This 72-year-old woman consulted us because of tremors.

Our patient had an asymmetric oscillation (about 4 Hz) of her relaxed left hand, with a predominant pronation-supination pattern, characteristic of parkinsonian tremor. Tremor consists of rhythmic, oscillating movements of agonist and antagonist muscles, in an alternating (such as in Parkinson disease) or co-contracting fashion (such as in dystonic tremor). A predominant resting tremor is typical of Parkinson disease and drug-induced parkinsonism, though it can be seen less often in atypical parkinsonisms.