Frontiers in neurology
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Frontiers in neurology · Jan 2018
Responsivity of Periaqueductal Gray Connectivity Is Related to Headache Frequency in Episodic Migraine.
Migraineurs show hypersensitivity to sensory stimuli at various stages throughout the migraine cycle. A number of putative processes have been implicated including a dysfunction in the descending pain modulatory system in which the periaqueductal gray (PAG) is considered to play a crucial role. Recurring migraine attacks could progressively perturb this system, lowering the threshold for future attacks, and contribute to disease chronification. ⋯ PAG connectivity with regions involved with the descending pain modulatory system (i.e., prefrontal cortex) was decreased in the migraineurs versus healthy individuals. Our results suggest that high frequency migraineurs may have diminished resistance to cephalic pain and a less efficient inhibitory pain modulatory response to external stressor (i.e., noxious heat). The findings support the notion that in migraine there is less effective pain modulation (viz., decreased pain inhibition or increased pain facilitation), potentially contributing to increased occurrence of attacks/chronification of migraine.
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Frontiers in neurology · Jan 2018
CSF Neurofilament Light Chain Levels in Primary Progressive MS: Signs of Axonal Neurodegeneration.
Objectives: Elevated neurofilament light chain (NFL) levels within the cerebrospinal fluid (CSF) are a biomarker representing axonal neurodegeneration in rapid progressive neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). It is unclear to what extent the levels of NFL increase in the CSF (CSF-NFL) in a chronic neuroinflammatory process with axonal neurodegeneration, as found in primary progressive multiple sclerosis (PPMS). Methods: We used a multicenter approach to statistically compare CSF-NFL levels between PPMS patients (n = 50), ALS patients (n = 50), and healthy controls (n = 50). ⋯ Results: Median [range] CSF-NFL concentrations in PPMS patients were significantly higher than in the controls [1724 (799-4275) pg/ml vs. 1202 (612-2934) pg/ml, p = 0.015], and significantly lower compared to ALS patients [1724 (799-4275) pg/ml vs. 10238 (2610-35138) pg/ml, p < 0.001]. There was no correlation between CSF-NFL and disease duration (p = 0.5), EDSS (p = 0.2) or treatment (p = 0.3). Conclusion: We conclude that CSF-NFL may mirror the proposed slow axonal degeneration in PPMS, but does not reflect the disease severity.
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Frontiers in neurology · Jan 2018
Detecting Cortical Spreading Depolarization with Full Band Scalp Electroencephalography: An Illusion?
There is strong evidence suggesting detrimental effects of cortical spreading depolarization (CSD) in patients with acute ischemic stroke and severe traumatic brain injury. Previous studies implicated scalp electroencephalography (EEG) features to be correlates of CSD based on retrospective analysis of EEG epochs after having detected "CSD" in time aligned electrocorticography. We studied the feasibility of CSD detection in a prospective cohort study with continuous EEG in 18 patients with acute ischemic stroke and 18 with acute severe traumatic brain injury. ⋯ With full band scalp EEG in patients with cortical ischemic stroke or traumatic brain injury, we observed various ISA, probably modulating cortical excitability. However, we were unable to identify unambiguous characteristics of CSD.