Using functional MRI (fMRI), we have studied the changes induced by the performance of a complex sequential motor task in the cortical areas of six akinetic patients with Parkinson's disease and six normal subjects. Compared with the normal subjects, the patients with Parkinson's disease exhibited a relatively decreased fMRI signal in the rostral part of the supplementary motor area (SMA) and in the right dorsolateral prefrontal cortex, as previously shown in PET studies. Concomitantly, the same patients exhibited a significant bilateral relative increase in fMRI signal in the primary sensorimotor cortex, lateral premotor cortex, inferior parietal cortex, caudal part of the SMA and anterior cingulate cortex. These fMRI data confirm that the frontal hypoactivation observed in patients with Parkinson's disease is restricted to the rostral part of the SMA and to the dorsolateral prefrontal cortex. These results also show that, apart from the lateral premotor and parietal cortices, increased fMRI signals can be found in other cortical motor areas of these patients, including the posterior SMA, the anterior cingulate cortex and the primary sensorimotor cortices, which are then likely to participate in the same putative attempt by the dopamine-denervated brain to recruit parallel motor circuits in order to overcome the functional deficit of the striatocortical motor loops.

No abstract

Key Points• Incidence of ITP was 2.9/100 000 person-years with age, seasonal, and regional variations; in adults, 18% were secondary. • Severe (gastrointestinal or central nervous system) bleeding at ITP onset was rare (,1%); the risk increased with age.The epidemiology of immune thrombocytopenia (ITP) is not well known. The purpose of this study was to assess ITP incidence at a nationwide level (France) with recent data (mid-2009 to mid-2011; 129 248 543 person-years). The data source is the French health insurance database. We selected cases with diagnosis codes for in-hospital stays and long-term disease attributions, thus restricting our search to ITPs necessitating health care. We studied incidence by age, gender, calendar month, regions, and proportion of secondary ITPs, of ITPs becoming persistent or chronic, and of severe bleeding at disease onset. We identified 3771 incident ITP patients. Incidence was 2.9/100 000 person-years, with peaks among children and in those >60 years of age. ITP was more frequent among males in these subgroups. The incidence was lower in overseas Caribbean French departments, suggesting a lower incidence among Afro-American people. There was a northsouth gradient in mainland France and seasonal variations (peak in winter and nadir in summer). Persistence or chronicity occurred in 36% of children compared with 67% of adults. Among adults, 18% of ITPs were secondary. Malignancy was the main cause (10.9%). Myelodysplastic syndromes were not rare (2.3%). Severe gastrointestinal or central nervous system bleeding at ITP onset was rare (<1%). (Blood. 2014;124(22):3308-3315)