Prelemniscal Lesion for Selective Improvement of Parkinson Disease Tremor.

BACKGROUND: Selective improvement of symptoms may be required when treating Parkinson disease (PD) patients with a predominantly monosymptomatic clinical picture.

OBJECTIVE: To define a target in prelemniscal radiation fibers (Raprl) related to the physiopathology of tremor evidenced by tractography.

CASE REPORT: We report a patient with predominant unilateral rest and postural tremor, diagnosed as PD based on 80% improvement induced by the administration of L-DOPA/carbidopa, subsequently complicated by motor fluctuations, L-DOPA dyskinesia, and a reduced ON period. A stereotactic radiofrequency lesion was made for tremor control, and postoperative diffusion-weighted imaging (DWI) demonstrated the precise location and extension of the lesioned tract.

RESULTS: Perfect control of the tremor was achieved with the patient OFF medication; this has lasted for 5 years, without hypotonia in the treated extremities. DWI revealed a 3.0-mm lesion at the base of the nucleus ventralis intermedius (Vim) interrupting cerebellar-Vim fibers sparing the cerebellar ventralis oralis posterior nucleus component.

CONCLUSION: Selective improvement of symptoms is feasible in patients with a predominantly monosymptomatic PD clinical presentation.