Tremor: Phenomenology, etiology, diagnosis, and treatment

Abstract

Tremor is an involuntary rhythmic, oscillatory movement produced by synchronous or alternating contractions of antagonist muscles. Tremor is the most common movement disorder and one of the most common neurological symptoms. A wide variety of etiologies can cause tremor, with essential tremor being the most common. Parkinson’s disease, multiple sclerosis, and drug-induced tremors are other etiologies commonly seen in clinical practice. The diagnosis of the specific etiology of tremor is based on the clinical characteristics of the tremor as well as associated symptoms. The phenomenology of tremor including whether the tremor is present at rest, with posture or with action, allows classification of tremor. Imaging studies, while not in themselves diagnostic, can help rule out structural etiologies. Dopamine transporter imaging is a recent modality that can help distinguish essential tremor from parkinsonism. The treatment of tremor is based on etiology and, where possible, treatment of the underlying disease state. Deep brain stimulation of the thalamus can be an effective treatment modality in intractable cases of tremor.