We studied whether the (123)I-FP-CIT uptake in the striatum correlates with depressive symptoms and cognitive performance in patients with Parkinson's disease (PD). Twenty patients with PD without major depression and/or dementia (mean age 61.7 +/- 12.7 years) underwent the (123)I-FP-CIT SPECT. Depressive symptoms and cognitive performance were assessed in the ON state. The ratios of striatal to occipital binding for the entire striatum, putamina, and putamen to the caudate (put/caud) index were calculated in the basal ganglia. The association between neuropsychiatric measures and dopamine transporter (DAT) availability was calculated; multiple regression analysis was used to assess association with age and disease duration. We found significant correlations between Montgomery and Asberg Depression Rating Scale (MARDS) and Tower of London (TOL) task scores and (123)I-FP-CIT uptake in various striatal ROIs. Multiple regression analysis confirmed the significant relationship between TOL performance and put/caud ratio (P = 0.001) and to age (P = 0.001), and between MADRS and left striatal (P = 0.005) and putaminal DAT availability (P = 0.003). Our pilot study results demonstrate that imaging with (123)I-FP-CIT SPECT appears to be sensitive for detecting dopaminergic deficit associated with mild depressive symptoms and specific cognitive dysfunction in patients with PD, yet without a current depressive episode and/or dementia.

The aim of the present study was to investigate the effects of one session of high-frequency repetitive transcranial magnetic stimulation (rTMS) applied over the left dorsal premotor cortex (PMd) and left dorsolateral prefrontal cortex (DLPFC) on choice reaction time in a noise-compatibility task, and cognitive functions in patients with Parkinson's disease (PD). Clinical motor symptoms of PD were assessed as well. Ten patients with PD entered a randomized, placebo-controlled study with a crossover design. Each patient received 10 Hz stimulation over the left PMd and DLPFC (active stimulation sites) and the occipital cortex (OCC; a control stimulation site) in the OFF motor state, i.e. at least after 12 h of dopaminergic drugs withdrawal. Frameless stereotaxy was used to target the optimal position of the coil. For the evaluation of reaction time, we used a noise-compatibility paradigm. A short battery of neuropsychological tests was performed to evaluate executive functions, working memory, and psychomotor speed. Clinical assessment included a clinical motor evaluation using part III of the Unified Parkinson's Disease Rating Scale. Statistical analysis revealed no significant effect of rTMS applied over the left PMd and/or DLPFC in patients with PD in any of the measured parameters. In this study, we did not observe any effect of one session of high frequency rTMS applied over the left PMd and/or DLPFC on choice reaction time in a noise-compatibility task, cognitive functions, or motor features in patients with PD. rTMS applied over all three stimulated areas was well tolerated and safe in terms of the cognitive and motor effects.

In PD patients, rTMS of the IFG increased the speed of cognitive processing in both the congruent and incongruent conditions of the ST.

We studied whether one session of high-frequency repetitive transcranial magnetic stimulation (rTMS) applied over either the right or left dorsolateral prefrontal cortex would induce any measurable changes in the Tower of London spatial planning task performance in patients with Parkinson's disease (PD). Ten patients with PD (with no dementia and/or depression) entered the randomized, sham-stimulation-controlled study with a crossover design. Active and placebo rTMS were applied over either the left or the right dorsolateral prefrontal cortex (in four separate sessions) in each patient. The order of sessions was randomized. The Tower of London task was performed prior to and immediately after each appropriate session. The "total problem-solving time" was our outcome measure. Only active rTMS of the right dorsolateral prefrontal cortex induced significant enhancement of the total problem-solving time, p = 0.038. Stimulation of the left prefrontal cortex or sham stimulations induced no significant effects. Only rTMS applied over the right dorsolateral prefrontal cortex induced positive changes in the spatial planning task performance in PD, which further supports the results of functional imaging studies indicating the causal engagement of the right-sided hemispheric structures in solving the task in this patient population.

We studied whether the cognitive event-related potentials (ERP) in the subthalamic nucleus (STN) are modified by the modulation of the inferior frontal cortex (IFC) and the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS). Eighteen patients with Parkinson's disease who had been implanted with a deep brain stimulation (DBS) electrode were included in the study. The ERPs were recorded from the DBS electrode before and after the rTMS (1 Hz, 600 pulses) over either the right IFC (10 patients) or the right DLPFC (8 patients). The ERPs were generated by auditory stimuli. rTMS over the right IFC led to a shortening of ERP latencies from 277 +/- 14 ms (SD) to 252 +/- 19 ms in the standard protocol and from 296 +/- 17 ms to 270 +/- 20 ms in the protocol modified by a higher load of executive functions (both P < 0.01). The application of rTMS over the DLPFC and the sham stimulation over the IFC showed no significant changes. The shortening of ERP latency after rTMS over the right IFC reflected the increase in the speed of the cognitive process. The rTMS modulation of activity of the DLPFC did not influence the ERP. Connections (the IFC-STN hyperdirect pathway) with the cortex that bypass the BG-thalamocortical circuitries could explain the position of the STN in the processing of executive functions.

Introduction:Cognitive deficit after stroke is common, and beginning cognitive rehabilitation as soon as possible is important to minimize the consequences of the impairment. The aim of this study was to use Addenbrooke's Cognitive Examination to compare cognitive function in nondemented and nondepressed stroke patients, 3-6 months after the stroke, with sex-and age-matched controls. Materials and Methods:A total of 156 participants were included (72 controls: 19 men, mean age 64.5 ± 12.4 years; 84 patients after stroke: 54 men, mean age 62.2 ± 9.0 years).Results: Statistically significant differences were identified between controls and stroke patients in total Addenbrooke's score (stroke patients, 86.2 points vs controls, 91.2 points; p<0.01), Verbal Production domain (stroke patients, 9.8 points vs controls, 11.5 points; p<0.01), and Memory domain (stroke patients, 19.5 points vs controls, 21.7 points; p<0.01). The difference was also statistically significant between subgroups of stroke patients and controls: patients with a right-sided brain lesion differed from controls in total scores (88.3 vs 91.3 points, respectively; p<0.05) and Verbal Production domain scores (9.9 vs 11.5 points, p<0.01), as did patients with left-sided brain lesions in total score (83.9 vs 91.3 points; p<0.01) and Memory (18.6 vs 21.7 points; p<0.01) and Verbal Production (9.6 vs 11.5 points; p<0.01) domains. Conclusion:This study shows the usability of Addenbrooke's Cognitive Examination 3-6 months after a stroke to detect mild cognitive decline, providing a basis for initiating cognitive rehabilitation as soon as possible.

No abstract

No abstract