Fatigue is associated with metabolic and density alterations of cortical and deep gray matter in Relapsing-Remitting-Multiple Sclerosis patients at the earlier stage of the disease: A PET/MR study.

Background: Fatigue is a common but complex symptom of multiple sclerosis. A central origin is now suggested as a key feature of its pathophysiology and gray matter (GM) structure seems to be (particularly) involved in the neurobiological basis of fatigue in multiple sclerosis (MS) patients.

Methods: We investigated, in a cohort of 17 Relapsing-Remitting-MS patients recruited within three years of disease diagnosis, the link between fatigue severity evaluated by the EMIF-SEP (a validated self-report questionnaire in French), and metabolic and density alterations of GM using positron emission tomography (PET) and magnetic resonance (MR) imaging using SPM5 (statistical parametric morphometry) analysis and voxel-based-morphometry.

Functional imaging of working memory in Parkinson's disease: compensations and deficits.

Background And Purpose: Over and above typical motor alterations, executive and working memory (WM) impairment can also occur in early idiopathic Parkinson's disease (PD). We aimed to investigate the compensatory neural processes involved in WM performance, as well as the networks involved in the long-term memory transfer from short-term stores in PD.

Methods: Relative cerebral blood flow (rCBF) was mapped with H2O(15)-PET in eight treated nondemented PD patients while performing a WM verbal double-task (Brown-Peterson paradigm) using both short (6-second) and long (18-second) delays.

Neuropsychological and 18FDG-PET studies in a family with idiopathic basal ganglia calcifications.

Idiopathic basal ganglia calcification (FIBGC) is a rare autosomal dominant neurodegenerative disease, the main clinical signs of which are parkinsonism, cognitive deterioration and/or psychiatric troubles. Familial forms are rare. The underlying basis is not known.

Reduced thalamic and cerebellar rest metabolism in relapsing-remitting multiple sclerosis, a positron emission tomography study: correlations to lesion load.

Magnetic resonance imaging (MRI) is the main tool for detecting central nervous system lesions in MS. However, classical anatomical MRI is unable to assess exactly disease related injury in normal-appearing brain tissue and to give information about the functional consequences of the disease, explaining weak correlation frequently observed between lesion load and clinical data. Recently, functional brain imaging techniques have provided new insights concerning pathophysiological processes of the disease.

Working memory and dopamine: clinical and experimental clues.

Working memory has been successively considered as a mnesic or executive process. The cognitive processes involved in working memory and the executive functions are closely linked. Most authors currently agree that executive functions include planning, attentional maintenance, mental flexibility and attentional inhibition.