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The objective is to study the involvement of the posterior medial cortex (PMC) in encoding and retrieval by visual and auditory memory processing. Intracerebral recordings were studied in two epilepsy-surgery candidates with depth electrodes implanted in the retrosplenial cingulate, precuneus, cuneus, lingual gyrus and hippocampus. We recorded the event-related potentials (ERP) evoked by visual and auditory memory encoding-retrieval tasks. In the hippocampus, ERP were elicited in the encoding and retrieval phases in the two modalities. In the PMC, ERP were recorded in both the encoding and the retrieval visual tasks; in the auditory modality, they were recorded in the retrieval task, but not in the encoding task. In conclusion, the PMC is modality dependent in memory processing. ERP is elicited by memory retrieval, but it is not elicited by auditory encoding memory processing in the PMC. The PMC appears to be involved not only in higher-order top-down cognitive activities but also in more basic, rather than bottom-up activities.

Background: The effect of brain-vessel pathology on mortality in 57 consecutive PD patients was studied. Methods: Baseline clinical, neuropsychological, ultrasonographic (US), and MR data obtained from patients who died (n = 18) during a 4-year follow-up period were compared with the data of patients who survived. Results: US/MRI data displayed a more-severe vascular impairment in deceased patients. Differences were significant between both groups with respect to age, clinical and cognitive status, intima-media thickness, and resistance index (indicators of large and small vessel impairment). The sum score of white-matter hyperintensities was significantly higher among decedents. A cluster analysis displayed two clusters that differed in the two parameters (i.e. in age and in sum score). Conclusions: This study provides evidence that comorbid atherosclerosis and otherwise subclinical impairment of brain vessels may contribute to mortality in PD. The vascular pathology may act in association with other comorbidities on the terrain of progressive neurodegenerative pathology. (C) 2012 Movement Disorder Society

The aim of our study was to analyse decision making in early-onset Parkinson's disease (PD) patients performing the Iowa Gambling Task (IGT). We compared 19 patients with early-onset PD (≤ 45 years) on dopaminergic medication (no evidence of depression, dementia, executive dysfunction according to the Tower of London test and the Stroop test, or pathological gambling) with 20 age-matched controls. A computer version of the IGT was employed. The PD patients achieved slightly lower IGT scores than the control group. A detailed analysis based on 'shift frequencies' between the individual decks showed that the patients tended to change their preferences for the decks more frequently, with a higher preference for the 'disadvantageous' deck B. Control subjects seemed to develop a more effective strategy. These differences could be caused by the poorer ability of the patients to develop any strategy at all. We observed changes in decision making during IGT performance in patients with early-onset PD, although they had no executive dysfunction as measured by established neuropsychological tests. The more detailed analysis employed in the present study could lead to a more accurate study of IGT performance and application of IGT in clinical practice.

Objective To study the involvement of the anterior thalamic nuclei (ANT) in the cognitive processes. Methods We recorded the event-related potentials (ERPs) by visual and auditory memory encoding-recognition tasks by intracerebral recordings in patients with pharmacoresistent epilepsy who underwent the deep brain stimulation (DBS) surgery of the anterior thalamic nuclei with depth electrodes implanted bilaterally in the ANT. We compared the results with epilepsy-surgery candidates with depth electrodes implanted bilaterally in the hippocampus. Results In the ANT we recorded ERPs during the visual encoding and visual and auditory recognition tasks. No significant ERPs were recorded during the encoding phase by auditory stimuli in ANT. In hippocampus ERPs were recorded by visual and auditory memory encoding and recognition tasks. In the recognition tasks (visual and auditory) the ERPs in ANT preceded the ERPs in hippocampus. Conclusions ERPs are elicited by visual memory encoding and recognition, as well as by auditory recognition memory processes, but not by encoding auditory memory processing in the ANT. The ANT precedes the hippocampus in the memory recognition pathway. Key message ANT has a specific role in the memory processes, especially the memory recognition.

We studied whether five sessions of 10 Hz repetitive transcranial magnetic stimulation (rTMS treatment) applied over the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (MC) in advanced Parkinson's disease (PD) patients would have any effect on L-dopa-induced dyskinesias and cortical excitability. We aimed at a randomised, controlled study. Single-pulse transcranial magnetic stimulation (TMS), paired-pulse transcranial magnetic stimulation, and the Unified Parkinson's Disease Rating Scale (UPDRS parts III and IV) were performed prior to, immediately after, and one week after an appropriate rTMS treatment. Stimulation of the left DLPFC induced a significant motor cortex depression and a trend towards the improvement of L-dopa-induced dyskinesias.

Repetitive Transcranial Stimulation for Freezing of Gait in Parkinson's Disease: the authors did not find any effect of rTMS applied over the motor cortex and/or DLPFC for freezing of gait in PD