Affiliations: [a] Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| [b] Department of Neuropsychology, National Hospital for Neurology and Neurosurgery, London, UK
| [c] Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| [d] Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
Correspondence:
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Correspondence to: Professor Tom Foltynie, Sobell Department of Motor Neuroscience and Movement Disorders (Box 146), UCL Institute of Neurology, London, WC1N 3BG, UK. Tel.: +44 203 448 8726; E-mail: t.foltynie@ucl.ac.uk.
Abstract: Background:Recent evidence suggests that glucosidase beta acid (GBA) mutations predispose Parkinson’s disease (PD) patients to a greater burden of cognitive impairment and non-motor symptoms. This emerging knowledge has not yet been considered in patients who have undergone deep brain stimulation (DBS); a surgery that is generally contraindicated in those with cognitive deficits. Objective:To explore the long-term phenotypic progression of GBA-associated PD, in a DBS cohort. Methods:Thirty-four PD patients who had undergone DBS surgery between 2002 and 2011 were included in this study; 17 patients with GBA mutations were matched to 17 non-carriers. Clinical evaluation involved the administration of four assessments: The Mattis Dementia Rating Scale was used to assess cognitive function; non-motor symptoms were assessed using the Non-Motor Symptom Assessment Scale for PD; quality of life was measured using the Parkinson’s Disease Questionnaire; and motor symptoms were evaluated using part III of the Movement Disorders Society Unified Parkinson’s Disease Rating Scale, in on-medication/on-stimulation conditions. Levodopa equivalent doses (LED) and DBS settings were compared with clinical outcomes. Results:At a mean follow-up of 7.5 years after DBS, cognitive impairment was more prevalent (70% vs 19%) and more severe in GBA mutation carriers compared to non-carriers (60% vs 6% were severely impaired). Non-motor symptoms were also more severe and quality of life more impaired in GBA-associated PD. Motor symptoms, LED, and stimulation settings were not significantly different between groups at follow-up. Conclusions:GBA status appears to be an important predictor for non-motor symptom disease progression, after deep brain stimulation surgery.
Keywords: Deep brain stimulation, glucosidase beta acid, Parkinson’s disease, phenotype
