Clinical and electromyographic examinations of patients with midbrain and cerebellar tremor.

The aim of this study was to re-evaluate the controversial clinical and electromyographic findings of cerebellar and midbrain tremors. Neurological examination and surface electromyographic tremor recordings were performed on 46 patients (24 with midbrain and 22 with cerebellar tremor). Our results revealed that the midbrain tremor has involved the hand, sometimes the ipsilateral leg and regions outside the limbs. Usually it was combined rest, postural, kinetic and intention tremor, the amplitude of each next tremor progressively increased. The tremor had high amplitude, low frequency and typical long burst duration. The cerebellar tremor was quite different, as it was predominantly postural and kinetic and involved the upper limbs. The tremor had synchronous electromyographic pattern, high frequency, low amplitude and short burst duration. In conclusion although the cerebellar and midbrain tremors are caused by involvement of very close anatomical regions and sometimes one type of tremor may become into another, they have quite different clinical and electromyographic presentations.