Aim: To evaluate the results of ventral intermediate (Vim) thalamic deep brain stimulation (DBS) in patients with tremor-predominant Parkinsonńs disease (PD) at 6 years post surgery.
Methods: This is a prolonged follow up on 38 patients from eight centers who participated in a multicenter study, the one year results of which had been published. Total scores as well as scores of individual items of the motor part, and the disability part, of the Unified Parkinsonńs Disease Rating Scale (UPDRS) were used for evaluation.
Results: It was found that tremor was still effectively controlled by DBS and that appendicular rigidity and akinesia remained stable compared to baseline. Axial scores (speech, gait and postural instability), however, worsened, and in parallel the initial improvement in activities of daily living scores at one year follow up had disappeared at six years, despite sustained improvement of tremor. Remarkably, neither daily doses of dopaminergic medication, nor fluctuations and dyskinesias had changed at six years compared to baseline in this particular patient group.
Conclusion: This study confirms that patients with tremor-dominant PD who do not present with fluctuations and dyskinesias may have a relatively benign progression of the disease. Vim DBS, although having no effect on akinesia and rigidity, is a relatively lenient surgical procedure and may still has a place for long term symptomatic control of PD tremor in selected patients.
- deep brain stimulation
- parkinsons disease
- ventral intermediate nucleus of thalamus