JAMA neurology
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Randomized Controlled Trial
Growth hormone-releasing hormone effects on brain γ-aminobutyric acid levels in mild cognitive impairment and healthy aging.
Growth hormone-releasing hormone (GHRH) has been previously shown to have cognition-enhancing effects. The role of neurotransmitter changes, measured by proton magnetic resonance spectroscopy, may inform the mechanisms for this response. ⋯ Twenty weeks of GHRH administration increased GABA levels in all 3 brain regions, increased NAAG levels in the frontal cortex, and decreased MI levels in the posterior cingulate. To our knowledge, this is the first evidence that 20 weeks of somatotropic supplementation modulates inhibitory neurotransmitter and brain metabolite levels in a clinical trial, and it provides preliminary support for one possible mechanism to explain favorable GHRH effects on cognition in adults with MCI and in healthy older adults. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00257712.
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β-amyloid (Aβ) deposition is one of the hallmarks of Alzheimer disease. Aβ deposition accelerates gray matter atrophy at early stages of the disease even before objective cognitive impairment is manifested. Identification of at-risk individuals at the presymptomatic stage has become a major research interest because it will allow early therapeutic interventions before irreversible synaptic and neuronal loss occur. We aimed to further characterize the cross-sectional and longitudinal relationship between Aβ deposition, gray matter atrophy, and cognitive impairment. ⋯ In asymptomatic individuals, Aβ deposition is associated with GM atrophy and memory impairment. The earliest signs of GM atrophy were detected in the hippocampus and the posterior cingulate and precuneus regions, and with disease progression, atrophy became more extensive in the temporal lobes. These findings support the notion that Aβ deposition is not a benign process and that interventions with anti-Aβ therapy at these early stages have a higher chance to be effective.
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The study of brain activity and connectivity at rest provides a unique opportunity for the investigation of the brain substrates of cognitive outcome after traumatic axonal injury. This knowledge may contribute to improve clinical management and rehabilitation programs. ⋯ Increased ALFF is related to better cognitive performance in chronic TBI. The loss of structural connectivity produced by damage to the cingulum tract explained the compensatory increases in functional connectivity within the frontal node of the DMN.
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Comparative Study
Microcystic inner nuclear layer abnormalities and neuromyelitis optica.
Microcystic abnormalities involving the inner nuclear layer of the retina occurs in a subset of patients with multiple sclerosis, most commonly in eyes previously affected by symptomatic optic neuritis. Acute optic neuritis is a cardinal manifestation of neuromyelitis optica (NMO). To our knowledge, microcystic inner nuclear layer abnormalities have not been investigated in NMO. ⋯ Microcystic inner nuclear layer pathology occurs in a proportion of patients with NMO in eyes previously affected by acute optic neuritis. Additional research is needed to understand the cause of this retinal pathology and determine whether it contributes to persistent visual disability in patients with NMO following optic neuritis.
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Randomized Controlled Trial Multicenter Study Comparative Study
Randomized controlled clinical trial of "virtual house calls" for Parkinson disease.
The burden of neurological disorders is increasing, but access to care is limited. Providing specialty care to patients via telemedicine could help alleviate this growing problem. ⋯ Using web-based videoconferencing to provide specialty care at home is feasible, provides value to patients, and may offer similar clinical benefit to that of in-person care. Larger studies are needed to determine whether the clinical benefits are indeed comparable to those of in-person care and whether the results observed are generalizable.