The results support the hypothesis that juvenile myoclonic epilepsy is associated with abnormalities of the thalamocortical network that can be detected by diffusion tensor MRI.

Cerebral amyloid angiopathy plays a major role in the pathogenesis of intracerebral hemorrhage even in patients with more evident risk factors.

BackgroundPrevious studies have reported white matter (WM) brain alterations in asymptomatic patients with human immunodeficiency virus (HIV).MethodsWe compared diffusion tensor imaging (DTI) derived WM fractional anisotropy (FA) between HIV-patients with and without mild macroscopic brain lesions determined using standard magnetic resonance imaging (MRI). We furthermore investigated whether WM alterations co-occurred with neurocognitive deficits and depression. We performed structural MRI and DTI for 19 patients and 19 age-matched healthy controls. Regionally-specific WM integrity was investigated using voxel-based statistics of whole-brain FA maps and region-of-interest analysis. Each patient underwent laboratory and neuropsychological tests.ResultsStructural MRI revealed no lesions in twelve (HIV-MRN) and unspecific mild macrostructural lesions in seven patients (HIV-MRL). Both analyses revealed widespread FA-alterations in all patients. Patients with HIV-MRL had FA-alterations primarily adjacent to the observed lesions and, whilst reduced in extent, patients with HIV-MRN also exhibited FA-alterations in similar regions. Patients with evidence of depression showed FA-increase in the ventral tegmental area, pallidum and nucleus accumbens in both hemispheres, and patients with evidence of HIV-associated neurocognitive disorder showed widespread FA-reduction.ConclusionThese results show that patients with HIV-MRN have evidence of FA-alterations in similar regions that are lesioned in HIV-MRL patients, suggesting common neuropathological processes. Furthermore, they suggest a biological rather than a reactive origin of depression in HIV-patients.

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FAIs based on mean fractional anisotropy values obtained from isotropic whole-head high-field diffusion tensor imaging by fully automated algorithms represent a robust and observer-independent measure for the comparative assessment of white matter integrity, ideally suited for further statistical treatments.