Tremor in Parkinson’s disease and essential tremor: practical aspects of differential diagnosis

Abstract

Despite the developed criteria of essential tremor (ET) and Parkinson’s disease (PD), clinical practice shows a high percentage of misdiagnoses, especially in the early stages of the disease and during the patient’s initial contact with a neurologist. In addition, the same patient may have signs of ET and PD at the same time. For a correct diagnosis, a detailed clinical examination is necessary. The specific characteristics of tremor (frequency, amplitude, type, involvement of specific parts of the body), history, associated neurological signs, and concomitant non-motor symptoms help to recognize and distinguish these two diseases. In order to exclude the possible negative effect of concomitant medications on tremor, it is necessary to find out about the medication history. The article offers an algorithm of survey and inspection, as well as the interpretation of the data obtained. In diagnostically complicated cases, «trial» therapy is carried out. Additional information for differential diagnosis can be provided by the results of instrumental methods of investigation of transcranial sonography of black substance and single-photon emission computed tomography (DaTSCAN).