Clinical outcomes from bilateral versus unilateral stimulation of the pedunculopontine nucleus with and without concomitant caudal zona incerta region stimulation in Parkinson's disease.

Introduction: The Pedunculopontine nucleus is a novel target for deep brain stimulation and this may improve postural instability and gait dysfunction in Parkinson's disease. If unilateral Pedunculopontine nucleus stimulation is as efficacious as bilateral stimulation this would lead to less surgical risk.

Methods: 5 Parkinson's disease patients with bilateral caudal Zona Incerta region and Pedunculopontine nucleus electrodes were assessed using the motor component of the Unified Parkinson's Disease Rating Scale. Patients were assessed in the on-medication state to determine the optimal combination of stimulation setting for axial symptom control.

Results: The on-medication composite axial-subscore only showed a statistically significant improvement when bilateral Pedunculopontine nucleus and caudal Zona Incerta region stimulation was used.

Conclusions: In the on-medication state bilateral Pedunculopontine nucleus and caudal Zona Incerta region stimulation is required in order to produce a significant change in the motor Unified Parkinson's Disease Rating Scale axial-subscore from baseline.