1,720,968 research outputs found
Functional MRI of sleep spindles and K-complexes
Objective: Sleep spindles and K-complexes are EEG hallmarks of non-REM sleep. However, the brain regions generating these discharges and the functional connections of their generators to other regions are not fully known. We investigated the neuroanatomical correlates of spindles and K-complexes using simultaneous EEG and fMRI. Methods: EEGs recorded during EEG-fMRI studies of 7 individuals were used for fMRI analysis. Higher-level group analyses were performed, and images were thresholded at Z >= 2.3. Results: fMRI of 106 spindles and 60 K-complexes was analyzed. Spindles corresponded to increased signal in thalami and posterior cingulate, and right precuneus, putamen, paracentral cortex, and temporal lobe. K-complexes corresponded to increased signal in thalami, superior temporal lobes, paracentral gyri, and medial regions of the occipital, parietal and frontal lobes. Neither corresponded to regions of decreased signal. Conclusions: fMRI of both spindles and K-complexes depicts signal subjacent to the vertex, which likely indicates each discharges' source. The thalamic signal is consistent with thalamic involvement in sleep homeostasis. The limbic region's signal is consistent with roles in memory consolidation. Unlike the spindle, the K-complex corresponds to extensive signal in primary sensory cortices. Significance: Identification of these active regions contributes to the understanding of sleep networks and the physiology of awareness and memory during sleep. (C) 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved
Natalizumab in spinal multiple sclerosis in a daily clinical setting
Objective: We aimed to investigate the influence of natalizumab (NTZ) treatment on multiple sclerosis course in patients with and without spinal involvement.Methods: Annualized relapse rate (ARR), disability progression and occurrence of new brain and spinal T2 lesions (N2TL) in 68 spinal (S-P) versus 68 non-spinal matched patients (NS-P) were retrospectively collected and compared between before (2 years) and after NTZ treatment using multivariate regression models.Results: Mean duration of NTZ treatment was 31.3 ± 16.3 months in S-P and 32.1 ± 15.1 months in N-SP (p = 0.56). The mean ARR after NTZ treatment was similarly reduced in both S-P (0.07 ± 0.19) and N-SP (0.07 ± 0.16) (p < 0.001 for both). Disability progression after NTZ start was similarly low in S-P and NS-P. However, when compared to before NTZ start, disability progression was significantly reduced in S-P (p = 0.017), but not in NS-P (p = 0.68). This was largely mediated by a higher disability progression before NTZ start in S-P than N-SP. The risk of developing N2TL during NTZ was not different between S-P and NS-P (p = 0.10).Conclusions: NTZ similarly reduced the occurrence of relapses and NT2L in S-P and NS-P, whereas the effect on disability progression was particularly evident in the presence of spinal involvement. NTZ appears to be a treatment of high efficacy in both S-P and NS-P
Fotosensibilità in una ragazza con S. di Hallermann-Streiff: associazione casuale o causale?
Sensitivity to intermittent photic stimulation in photosensitive patients: is there a circadian rhythm?
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