Comparison of arterial spin labeling registration strategies in the multi-center GENetic frontotemporal dementia initiative (GENFI)

Neuro Imaging Researc

Event-related alpha and theta responses in a visuo-spatial working memory task

Objective: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. Methods: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4 s retention interval. The target either remained visible throughout the entire interval (sensory trials) or disappeared after 150 ms (memory trials). Changes in induced band power (IBP) in the electroencephalogram (EEG) were analyzed in 4 narrow, individually adjusted frequency bands between 4 and 12 Hz. Results: After presentation of the target stimulus, a phasic power increase was found, irrespective of condition and delay interval, in the lower (roughly, 4–8 Hz) frequency bands, with a posterior maximum. During the retention interval, sustained occipital–parietal alpha power increase and frontal theta power decrease were found. Most importantly, the memory trials showed larger IBP decreases in the theta band over frontal electrodes than the sensory trials. Conclusions: The phasic power increase following target onset is interpreted to reflect encoding of the target location. The sustained theta decrease, which is larger for memory trials, is tentatively interpreted to reflect visuo-spatial working memory processes

Neural response to alcohol taste cues in youth: effects of the OPRM1 gene

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Hippocampal avoidance prophylactic cranial irradiation (HA-PCI) for small cell lung cancer reduces hippocampal atrophy compared to conventional PCI

Background Reducing radiation dose to the hippocampus with hippocampal avoidance prophylactic cranial irradiation (HA-PCI) is proposed to prevent cognitive decline. It has, however, not been investigated whether hippocampal atrophy is actually mitigated by this approach. Here, we determined whether HA-PCI reduces hippocampal atrophy. Additionally, we evaluated neurotoxicity of (HA-)PCI to other brain regions. Finally, we evaluated associations of hippocampal atrophy and brain neurotoxicity with memory decline. Methods High-quality research MRI scans were acquired in the multicenter, randomized phase 3 trial NCT01780675. Hippocampal atrophy was evaluated for 4 months (57 HA-PCI patients and 46 PCI patients) and 12 months (28 HA-PCI patients and 27 PCI patients) after (HA-)PCI. We additionally studied multimodal indices of brain injury. Memory was assessed with the Hopkins Verbal Learning Test–Revised (HVLT-R). Results HA-PCI reduced hippocampal atrophy at 4 months (1.8% for HA-PCI and 3.0% for PCI) and at 12 months (3.0% for HA-PCI and 5.8% for PCI). Both HA-PCI and PCI were associated with considerable reductions in gray matter and normal-appearing white matter, increases in white matter hyperintensities, and brain aging. There were no significant associations between hippocampal atrophy and memory. Conclusions HA-PCI reduces hippocampal atrophy at 4 and 12 months compared to regular PCI. Both types of radiotherapy are associated with considerable brain injury. We did not find evidence for excessive brain injury after HA-PCI relative to PCI. Hippocampal atrophy was not associated with memory decline in this population as measured with HVLT-R. The usefulness of HA-PCI is still subject to debate

Alger socialiste : organe officiel de la Fédération socialiste d'Alger

08 novembre 19241924/11/08 (A6,N165)-1924/11/08