Unilateral Holmes tremor, clearly responsive to cerebrospinal fluid release, in a patient with an ischemic midbrain lesion and associated chronic hydrocephalic ventricle enlargement. Case report.

The authors describe a 58-year-old man with sudden onset of a unilateral tremor caused by a midbrain lesion that affected the substantia nigra and the cerebellothalamic pathway. There were also clinical and neuroimaging signs of a communicating chronic hydrocephalus. The patient was severely handicapped by this tremor, which was a typical Holmes tremor with rest, posture, and intention components. Parkinson disease or multiple-system atrophy as causes for the tremor could be ruled out by DaTSCAN and 123I iodobenzamide and single-photon emission computerized tomography (SPECT), respectively. The tremor was completely supressed by temporary and permanent cerebrospinal fluid release after ventriculoperitoneal shunt placement, without any additional medication, for a period of 6 months. Afterward, the tremor returned, and the patient had to be treated by a stereotactic electrode implantation in the contralateral ventralis intermedius nucleus, which led to complete tremor suppression during the 1.5-year follow-up period. In this case report, the authors present the clinical description and the electrophysiological, SPECT, and magnetic resonance imaging data of a rare combination of symptoms and their surgical treatment.