Diagnosis and Treatment of Essential Tremor

Abstract

Purpose of review: Essential tremor is a chronic, progressive syndrome that primarily presents with an action tremor involving the arms and hands. This article reviews the history and physical examination features pertinent for diagnosis, differential diagnoses, and treatments and approaches for optimal control of symptoms.

Recent findings: Essential tremor is a syndrome with symptoms extending beyond tremor to involve disturbances in gait, speech, cognition, and mood. Although the new guidelines on the definition and biaxial classification scheme have provided clarity, some tremor experts have critiqued the recently coined term essential tremor plus. For treatment, new orthotic devices and peripheral stimulation devices are now available in addition to pharmacologic and surgical options.

Summary: Essential tremor has a rich clinical phenomenology with many subtleties and nuances. A detailed history with open-ended questions and focused questions encompassing medical history, social history, and family history is key for establishing the diagnosis. The presence of bilateral action tremor for 3 years and absence of isolated head and voice tremor and absence of task- and position-dependent tremor are necessary for diagnosis. Dystonic tremor, Parkinson disease tremor, physiologic tremor, and drug-induced tremor are common differential diagnoses. Differentiating these tremor disorders from essential tremor based on phenomenology and physical examination alone could be challenging; thus, clinicians should seek additional clues from a detailed history. Treatment could begin with noninvasive and nonpharmacologic therapies, especially in mild cases. As the severity increases, they can advance stepwise to include pharmacotherapies and surgical interventions. With the growing recognition that essential tremor is not a monosymptomatic disorder, management should involve a multidisciplinary team. Furthermore, treatment selection should be based on shared decision making between patients and providers that gives due consideration to severity of symptoms, level of functional disability, impact on social interactions, patient preferences, and patient expectations.

FIGURE 5-1. Differential diagnoses of essential tremor with key characteristics for individual tremor disorders.

FIGURE 5-2. Conceptual understanding of tremor. The horizontal arrows indicate the time interval between two successive peaks of periodic waves. Rhythmic tremor that is regularly recurrent has a constant interval. Irregular tremors with changing time intervals will clinically appear as jerky. Oscillation indicates rotation around a central plane. Vertical arrows of different lengths mean that the tremor is nonoscillatory. Such tremors clinically appear as directional. If the periodic waves lose their sinusoidal characteristics and assume sawtooth waves, such tremors will also clinically appear jerky.

FIGURE 5-3. Multidisciplinary team for management of essential tremor, which should be centered on the patient and not the disease.

FIGURE 5-4. Stepwise approach for management of arm symptoms in essential tremor. Treatments assigned to step 2 or 3 can be combined with treatments in step 1. Surgical treatments, even though powerful, are considered only when the tremor is refractory to pharmacologic therapies.

DBS = deep brain stimulation; MRI = magnetic resonance imaging.