Dr. Melanie Brandabur at The Parkinson’s Institute told me recently that only 7-8% of those diagnosed with parkinsonism are good candidates for DBS (deep brain stimulation). The other 92% do not respond well to levodopa, have something else medically going on, or have atypical parkinsonism.
Despite that, there continues to be huge interest in DBS for those with Parkinson’s Disease. And now, CurePSP announced that it is funding a small study of DBS in six PSPers at Toronto Western Hospital. Patients will be followed for up to one year after surgery. The hope is that walking and balance will be improved through this type of brain surgery.
If memory serves (which it doesn’t always), DBS in PD is bilateral (both right and left) and focused on the sub-thalamic nucleus (STN). In the study below, DBS will be unilateral (one side of the brain only) and will be focused on the pedunculopontine nucleus (PPN).
(Note that there was a research report of one South Carolina patient with a clinical DX of PSP-P who received STN DBS. That patient did improve, according to the research published in 9/07. PubMed ID#: 17825599)
Here’s info on the study being funded — first a non-technical summary and then a technical abstract:
http://www.psp.org/doc_library/12283993 … ebsite.pdf –> see pages 12 and 13
CurePSP Magazine
Fall 2008
Cure PSP Awards Two New Grants in Spring 2008
Unilateral Pedunculopontine Deep Brain Stimulation in PSP
Elena Moro, MD, PhD — Movement Disorders Center, Toronto Western Hospital
Lay Abstract
Deep brain stimulation (DBS) involves delivering electricity to specific brain regions through surgically implanted electrodes. There is recent evidence suggesting that DBS in a new brain surgical target, the pedunculopontine nucleus (PPN), may improve walking and postural problems in patients with Parkinson’s disease. As walking and balance are major struggle in progressive supranuclear palsy (PSP), we have designed a study aimed at investigating safety and efficacy of PPN DBS in patients with PSP. Six PSP patients will have unilateral PPN DBS surgery. Motor and non-motor symptoms will be evaluated before and after surgery up to 1 year. A specific study of walking and balance will also be conducted to assess potential improvement from PPN DBS. Beneficial effects obtained with PPN DBS in the treatment of walking and balance disturbances in PSP will likely improve the quality of life in these patients.
Structured Technical Abstract
Background: Gait impairment and postural instability are disabling motor features of progressive supranuclear palsy (PSP). In Parkinson’s disease (PD), deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) is currently investigated as a new surgical therapy to address axial signs (gait and balance).
Objectives and Hypotheses: To investigate whether unilateral PPN-DBS is safe and effective in PSP patients. We hypothesize that PPN-DBS will improve gait, postural instability and quality of life, without worsening other motor signs and condition. PPNDBS will possibly increase activation of the frontal cortex during PET scans.
Specific Aims: In Aim 1 we will study the effects of PPN-DBS using clinical scales, such as the PSP Rating Scale (PSPRS), the Unified Parkinson’s Disease Rating Scale (UPDRS) and the PSP Quality of Life scale. In Aim 2 we will analyze the effects of PPNDBS in gait initiation, spatiotemporal characteristics of gait and postural sway. In Aim 3 cerebral blood flow (rCBF) changes in cortical and subcortical regions will be studied with and without PPN-DBS using PET imaging.
Study Design: Six PSP patients with prominent axial motor signs (gait and balance impairment) will be enrolled. Patients will be assessed before and after surgery (at 3, 6 and 12 months) using the PSPRS, the UPDRS and the PSP QoL questionnaire. Assessments will be performed with and without dopaminergic medications and with and without PPN-DBS. Neuropsychological and psychiatric assessments will be performed preoperatively and at 6-month follow-up. Patients will also have gait analysis and posturography study before and after surgery (with and without stimulation). All patients will have unilateral PPN-DBS surgery using MRI and intraoperative microrecording for targeting. Patients will also undergo rCBF PET scan imaging with and without stimulation.
PSP Relevance: PPN-DBS could be an effective surgical treatment and improve gait, postural disturbances and quality of life in PSP patients.