[Psychogenic tremor: a positive diagnosis]

Psychogenic movement disorders are a daily challenge for the neurologist. A mistake in its recognition may have important consequences for the patients. As a result, the diagnosis must be considered very carefully in clinical practice. However, psychogenic movement disorders are not unusual, are mainly tremors, and a wrong diagnosis is common. Psychogenic is an unspecific term that usually masks the real mental disorder, and should be called somatoform disorders, factitious disorders, malingering, depression, anxiety and histrionic personality disorder, although the absence of a psychiatric diagnosis does not preclude a psychogenic cause. The diagnosis may often be difficult and should be made by an expert neurologist. Organic movement disorders must be excluded after a detailed neurological history, examination, and appropriate diagnostic studies. Psychogenic tremor is not only a diagnosis of exclusion, it can be diagnosed positively by its neurological signs, mainly: variability in frequency and amplitude, bilateral and sudden onset, non-progressive with frequent remissions, absence of finger, tongue or face tremor and coactivation of antagonistic muscles. Several tests can be useful in diagnosis, such as: accelerometry, EMG and response to placebo or suggestion. The treatment requires close cooperation between the medical team and patient. The problem must never be minimised and early diagnosis and treatment must be attempted.