241 research outputs found
Effects of manganese exposure on olfactory functions in teenagers: A pilot study
Long-term exposure to environmental manganese (Mn) affects not only attention and neuromotor functions but also olfactory functions of a pre-adolescent local population who have spent their whole life span in contaminated areas. In order to investigate the effect of such exposure at the level of the central nervous system we set up a pilot fMRI experiment pointing at differences of brain activities between a non-exposed population (nine subjects) and an exposed one (three subjects). We also measured the volume of the olfactory bulb as well as the identification of standard olfactory stimuli. Our results suggest that young subjects exposed to Mn exhibit a reduction of BOLD signal, subjective odor sensitivity and olfactory bulb volume. Moreover a region of interest SPM analysis showed a specifically reduced response of the limbic system in relation to Mn exposure, suggesting an alteration of the brain network dealing with emotional responses
White matter changes in corticobasal degeneration syndrome and correlation with limb apraxia
BACKGROUND:
Data on white matter changes in corticobasal degeneration syndrome (CBDS) are not yet available, whereas cortical gray matter loss is a feature of this condition. The structural abnormalities related to a key feature of CBDS (limb apraxia) are unknown.
OBJECTIVES:
To measure selective structural changes in early CBDS using diffusion tensor imaging and voxel-based morphometry and to evaluate the structural correlates of limb apraxia.
DESIGN:
Patient and control group comparison.
SETTING:
Referral center for dementia and movement disorders.
PARTICIPANTS:
Twenty patients with CBDS and 21 matched control subjects.
INTERVENTIONS:
Clinical and standardized neuropsychological evaluations, including assessment of limb apraxia.
MAIN OUTCOME MEASURES:
Gray and white matter changes in early CBDS.
RESULTS:
Diffusion tensor imaging revealed decreases in fractional anisotropy in the long frontoparietal connecting tracts, the intraparietal associative fibers, and the corpus callosum. Fractional anisotropy was also reduced in the sensorimotor projections of the cortical hand areas. Voxel-based morphometry showed a prevalent gray matter reduction in the left hemisphere (in the inferior frontal and premotor cortices, parietal operculum, superotemporal gyrus, and hippocampus). The pulvinar, bilaterally, and the right cerebellar cortex also showed atrophy. Limb apraxia correlated with parietal atrophy and with fractional anisotropy reductions in the parietofrontal associative fibers (P < .01). The limb-kinetic component of apraxia correlated with reduction of hand sensorimotor connecting fibers.
CONCLUSIONS:
The present integrative approach to in vivo structural anatomy combines hodologic imaging, describing patterns of white matter connections between cortical areas, with neuropsychological data. This provides new evidence of gray matter and fiber tract abnormalities in early-phase disease and contributes to clarifying the neural basis of apraxia in CBDS
Early aphasia rehabilitation is associated with functional reactivation of the left inferior frontal gyrus a pilot study
Background and Purpose—Early poststroke aphasia rehabilitation effects and their functional MRI (fMRI) correlates were
investigated in a pilot, controlled longitudinal study.
Methods—Twelve patients with mild/moderate aphasia (8 Broca, 3 anomic, and 1 Wernicke) were randomly assigned to
daily language rehabilitation for 2 weeks (starting 2.2 [mean] days poststroke) or no rehabilitation. The Aachen Aphasia
Test and fMRI recorded during an auditory comprehension task were performed at 3 time intervals: mean 2.2 (T1), 16.2
(T2), and 190 (T3) days poststroke.
Results—Groups did not differ in terms of age, education, aphasia severity, lesions volume, baseline fMRI activations,
and in task performance during fMRI across examinations. Rehabilitated patients significantly improved in naming and
written language tasks (P<0.05) compared with no rehabilitation group both at T2 and T3. Functional activity at T1 was
reduced in language-related cortical areas (right and left inferior frontal gyrus and middle temporal gyrus, right inferior
parietal lobule and superior temporal gyrus) in patients compared with controls. T2 and T3 follow-ups revealed a cortical
activation increase, with significantly greater activation in the left hemisphere areas in rehabilitated patients at T2 and T3,
and a timeĂ—treatment effect at T2 in the left inferior Broca area after rehabilitation. Left inferior frontal gyrus activation
at T2 significantly correlated with naming improvement.
Conclusions—Early poststroke aphasia treatment is useful, has durable effects, and may lead to early enhanced recruitment
of brain areas, particularly the left inferior frontal gyrus, which persists in the chronic phase
Impact of Physical Exercise Alone or in Combination with Cognitive Remediation on Cognitive Functions in People with Schizophrenia: A Qualitative Critical Review
: Physical exercise and cognitive remediation represent the psychosocial interventions with the largest basis of evidence attesting their effectiveness in improving cognitive performance in people living with schizophrenia according to recent international guidance. The aims of this review are to provide an overview of the literature on physical exercise as a treatment for cognitive impairment in schizophrenia and of the studies that have combined physical exercise and cognitive remediation as an integrated rehabilitation intervention. Nine meta-analyses and systematic reviews on physical exercise alone and seven studies on interventions combining physical exercise and cognitive remediation are discussed. The efficacy of physical exercise in improving cognitive performance in people living with schizophrenia is well documented, but more research focused on identifying moderators of participants response and optimal modalities of delivery is required. Studies investigating the effectiveness of integrated interventions report that combining physical exercise and cognitive remediation provides superior benefits and quicker improvements compared to cognitive remediation alone, but most studies included small samples and did not explore long-term effects. While physical exercise and its combination with cognitive remediation appear to represent effective treatments for cognitive impairment in people living with schizophrenia, more evidence is currently needed to better understand how to implement these treatments in psychiatric rehabilitation practice
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