Archives of neurology
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Archives of neurology · Jul 2009
Dysfunction of the default mode network in Parkinson disease: a functional magnetic resonance imaging study.
To examine the integrity of the default mode network in patients with Parkinson disease (PD). Previous functional neuroimaging experiments have studied executive deficits in patients with PD with regard to task-related brain activation. However, recent studies suggest that executive performance also relies on the integrity of the default mode network (ie, medial prefrontal cortex, posterior cingulate cortex, precuneus, and lateral parietal and medial temporal cortices), characterized by a deactivation of these cortical areas during the performance of executive tasks. ⋯ We describe specific malfunctioning of the default mode network during an executive task in PD. This finding is plausibly linked to dopamine depletion and may critically contribute to the understanding of executive deficits in PD.
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Archives of neurology · Jun 2009
Multicenter Study Meta AnalysisDefining survival as an outcome measure in amyotrophic lateral sclerosis.
To examine how respiratory interventions affect survival as an outcome measure and to define survival rate for trials in amyotrophic lateral sclerosis. ⋯ Tracheostomy and permanent assisted ventilation are not equivalent to death in amyotrophic lateral sclerosis. The use of respiratory interventions differs between centers, leading to variability in combined outcome assessments. The time to the end point can differ significantly depending on its definition, and combining outcomes does not reduce the estimated sample size of a trial. The death rate alone is the least variable and most easily identifiable measure of survival rate in amyotrophic lateral sclerosis.
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Archives of neurology · Jun 2009
Case Reports Clinical TrialCognitive functions in a patient with Parkinson-dementia syndrome undergoing deep brain stimulation.
Dementia represents one of the most challenging health problems. Despite intense research, available therapies have thus far only achieved modest results. Deep brain stimulation (DBS) is an effective treatment option for some movement disorders and is under study for psychiatric applications. Recently, diencephalic DBS revealed selective effects on memory functions, another facet of subcortical DBS. ⋯ Such a broad effect on cognition is consistent with ample experimental evidence revealing that the nucleus basalis of Meynert provides cholinergic innervation to the cortical mantle, complemented by glutaminergic and gamma-aminobutyric acid-transmitting projections from the basal forebrain. These projections provide background tuning facilitating cortical operations. Furthermore, nucleus basalis of Meynert stimulation paired with sensory stimuli can accomplish persistent reorganization of specific processing modules. The improvements in cognitive and behavioral performance in our patient are likely to be related to the effects of stimulating residual cholinergic projections and cell bodies in the nucleus basalis of Meynert.
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Archives of neurology · Jun 2009
Use of antithrombotic drugs and the presence of cerebral microbleeds: the Rotterdam Scan Study.
Cerebral microbleeds are hemosiderin deposits in the brain that are indicative of microangiopathy. Microbleeds in strictly lobar brain locations have been related to cerebral amyloid angiopathy, a bleeding-prone disease state. ⋯ This cross-sectional study shows that use of platelet aggregation inhibitors is related to the presence of cerebral microbleeds. Furthermore, aspirin and carbasalate calcium use may differently relate to the presence of strictly lobar microbleeds.