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Deep brain stimulation of the pedunculopontine nucleus area is no panacea for gait disorders in Parkinson's disease, according to a new study. The PPN is involved in locomotion control, and previous studies of open-label PPN stimulus have reported dramatic improvement. Six patients with PD and severe gait disorder were recruited. All patients already had DBS electrodes in place in the STN. Patients ranged from 56 to 72 at the time of PPN surgery, with daily levodopa equivalent dose ranging from 0 to 1170 mg/day. All patients had freezing of gait, and 4 had postural instability, both off medication. Electrodes were implanted bilaterally into the PPN. Patients underwent baseline evaluation one month before surgery, stimulation parameter setting for 3 months post-surgery, a subsequent 3-month double-blind evaluation protocol, and a final evaluation 12 months post-surgery. At the 12-month follow-up, objective freezing off levodopa improved in 5 patients, and worsened in 1, while the on-levodopa score improved in 4 and worsened in 1 (1 patient was not taking levodopa). Composite gait score off levodopa improved in 2 patients, remained unchanged in 2, and worsened in 2, while the on-levodopa score improved in 1, remained unchanged in 3, and worsened in 1. Double-blind evaluation of freezing on and off levodopa showed no overall significant difference between on versus off PPN stimulation, although 2 patients did improve on stimulation on levodopa. "There has been growing enthusiasm for pedunculopontine nucleus stimulation after the encouraging report of the first, open and short-term studies," the authors state. However, "One year after surgery, low-frequency stimulation of this area shows variable results, from fair improvement to worsening of freezing in one case..Since improvement can be fair in some patients, further evaluation in larger controlled trials is needed. Patients with severe freezing, leading to falls, may be better candidates." Effects of pedunculopontine nucleus area stimulation on gait disorders in Parkinson's disease MU Ferraye, B Debu, V Fraix, L Goetz, C Ardouin, J Yelnik, C Henry-Lagrange, E Seigneuret, B Piallat, P Krack, JF Le Bas, AL Benabid, S Chabardes, P Pollak Brain 2010;133:205-214 ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn