PPNa DBS for gait and balance disorders in Parkinson's disease: a double blind, randomised study
Gait and balance disorders are the major source of motor disabilities in advanced forms of Parkinson's disease (PD) Low frequency stimulation of the pedunculopontine nucleus area (PPNa DBS) has been recently proposed to treat these symptoms with variable clinical results. To further understand the effects of PPNa DBS on resistant gait and balance disorders, we performed a randomised double blind cross over study in six PD patients. Evaluation included clinical assessment of parkinsonian disability, quality of life and neurophysiological recordings of gait. Evaluations were done 1 month before, 4 and 6 months after surgery with four double blinded conditions assessed: with and without PPNa DBS, with and without levodopa treatment. Four patients completed the study and two patients were excluded from the final analysis because of peri operative adverse events (haematoma, infection) Clinically, the combination of PPNa DBS and levodopa treatment produced a significant decrease of the freezing episodes. The frequency of falls also decreased in three out of four patients. From a neurophysiological point of view, PPNa DBS significantly improved the anticipatory postural adjustments and double stance duration, but not the length and speed of the first step. Interestingly, step length and speed improved after surgery without PPNa DBS, suggesting that the lesioning effect of PPNa DBS surgery alleviates parkinsonian akinesia. Quality of life was also significantly improved with PPNa DBS. These results suggest that PPNa DBS could improve gait and balance disorders in well selected PD patients. However, this treatment may be riskier than others DBS surgeries in these patients with an advanced form of PD.
Journal of Neurology