Introduction: Tremor is frequent in neurologic practice but primary orthostatic tremor was first described in 1984. Its prevalence accounts for around 4% for tremors explored in neurophysiology; in contrast, essential and parkinsonian tremors represent respectively 28 and 22% of these cases.
Exegesis: Orthostatic tremor is characterized by its appearance while standing. Walking, sitting, and lying down are unaffected. Clinical examination is normal except for unsteadiness disappearing when walking. Surface electromyography in the standing position is necessary for the diagnosis and shows a regular rapid tremor (frequency around 14 to 18 Hz). Its pathophysiology is unknown.
Conclusion: Clonazepam is the first-line treatment for orthostatic tremor. In cases of resistance or side effects of this drug orthostatic tremor may be improved by primidone or, as in our case, gabapentin.