Clinical and electromyographic examinations of patients with psychogenic tremor.

The diagnosis of psychogenic tremor is difficult, as it is based on exclusion of all possible causes for organic tremor. The aim of this examination was to evaluate some typical clinical and electromyographic features of the psychogenic tremor. Twenty-nine patients with psychogenic tremor were examined and followed up for more than 36 months. Surface electromyographic recordings of the most involved limb in all positions were performed. The tremor was assessed also during different distractive methods. We found that typical symptoms are the sudden onset from more than one limb and in more than one limb position and the lack of progression. Tremor was accompanied by muscle contraction of both agonistic and antagonistic muscles. EMG recorded tremor was with alternating pattern and variable amplitude and frequency. In conclusion there are typical clinical and EMG symptoms that are useful for the early diagnosis of psychogenic tremors, while with the progression of the disease these symptoms are no more evident.