The potential neuromodulatory impact of subthalamic nucleus deep brain stimulation on Parkinson's disease progression.

INTRODUCTION: STN-DBS has been claimed to change progressionsymptomsin animal models of PD, but information is lacking about the possible neuromodulatory role of STN-DBS in humans. The aim of this prospective controlled study was to evaluate the long-term impact of STN-DBS on motor disabilities and cognitive impairment in PD patients in comparison to Best-Medical-Therapy (BMT) and Long-term-Post-Operative (POP) groups. MATERIAL AND METHODS: Patients were divided into 3 groups: the BMT-group consisted of 20 patients treated only with pharmacotherapy, the DBS-group consisted of 20 PD patients who underwent bilateral STN-DBS (examined pre- and postoperatively) and the POP-group consisted of 14 long-term postoperative patients in median 30 month-time after DBS. UPDRS III scale was measured during 3 visits in 9 ± 2 months periods (V1, V2, V3) in total-OFF phase. Cognitive assessment was performed during each visit in total-ON phase. RESULTS: The comparable UPDRS III OFF gain was observed in both BMT-group and POP-group evaluations (p < 0.05). UPDRS III OFF results in DBS-group revealed significant UPDRS III OFF increase in ΔV2-V1 assessment (p < 0.05) with no significant UPDRS III OFF alteration in ΔV3-V2 DBS-group evaluation (p > 0.05). Cognitive assessment revealed significant alterations between DBS-group and BMT-group in working memory, executive functions and learning abilities (p < 0.05). CONCLUSIONS: The impact of STN-DBS on UPDRS III OFF score and cognitive alterations suggest its neuromodulatory role, mainly during the first 9-18 months after surgery.

Verbal fluency in research conducted with PET technique under conditions of extended cognitive activation with the use of 18F-fluorodeoxyglucose (FDG) tracer. / Fluencja slowna w badaniach technika PET w warunkach przedluzonej aktywizacji poznawczej z zastosowaniem znacznika 18F-fluorodeoksyglukozy (FDG).

OBJECTIVES: Functional neuroimaging of the brain is a widely used method to study cognitive functions. The aim of this study was to compare the activity of the brain during performance of the tasks of phonemic and semantic fluency with the paced-overt technique in terms of prolonged activation of the brain. METHODS: The study included 17 patients aged 20-40 years who were treated in the past for Hodgkin'slymphoma, now in remission. Due to the type of task, the subjectswere divided into two groups. Nine people performed the phonemic fluency task, and eight semantic. Due to the disease, all subjects were subject to neuropsychological diagnosis. The diagnosis of any cognitive impairment was an exclusion criterion. Neuroimaging was performed using PET technique with 18F-fluorodeoxyglucose (FDG) tracer. RESULTS: Performance of a verbal fluency test, regardless of the version of the task, was associated with greater activity of the left hemisphere of the brain. The most involved areas compared with other areas of key importance for the performance of verbal fluency tasks were frontal lobes. An increased activity of parietal structures was also shown. CONCLUSIONS: The study did not reveal differences in brain activity depending on the type of task. Performing the test in both phonemic and semantic form for a long time, in terms of increased cognitive control resulting from the test procedure, could result in significant advantage of prefrontal lobe activityin both types of tasks and made it impossible to observe the processes specific to each of them.