[Tremor].

Tremor is one of the most frequent neurological signs. The correct clinical classification is mainly clinical. The most frequent primarily neurological tremor is essential tremor (prevalence 2 to 5%). It presents in most cases as a more or less symmetrical postural and kinetic tremor. In about 60% of cases an autosomal-dominant inheritance is found. Tremor may manifest not only in the hands but also in the head and voice. In about 60 to 70% of the patients alcohol may improve the tremor. Parkinsonian tremor is normally a tremor at rest and it starts asymmetrically. The legs and the face are frequently involved. Cerebellar tremor is intentional. Orthostatic tremor, which has a high frequency, mainly manifests in the legs and gives rise to postural instability. Dystonic tremor is an action tremor of the affected region of the body. Drug therapy, which is purely symptomatic, mostly depends on clinical manifestation. Postural and action tremors respond to non selective betablockers (propranolol), primidone, some antiepileptics (gabapentin, toparimate) and benzodiazepines. Classical rest tremors are improved by dopaminergic substances (levodopa, dopamine agonists) or anticholinergics. Dystonic tremor may successfully be treated by injections of botulinum toxin. Orthostatic tremor responds to gabapentin or benzodiazepines in some of the patients. In severely handicapped patients with refractory tremors the implantation of thalamic stimulation electrodes may be considered. This treatment may be very successful, however, its inherent risks have to be taken into account.