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Parental migraine in relation to migraine in offspring: Family linkage analyses from the HUNT Study.
Migraine is known to run in families. While some clinical studies have indicated that migraine is disproportionally transmitted through the maternal line, this has not been examined in a population-based setting.
Learn More >In this report we describe a series of patients with a previously undescribed headache.
Learn More >Carbonic anhydrase-8 (CA8) is an intracellular protein that functions as an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1) critical to intracellular Ca++ release, synaptic functions and neuronal excitability. We showed previously that murine nociception and analgesic responses are regulated by the expression of this gene in dorsal root ganglion (DRG) associated with a cis-eQTL. In this report, we identify an exon-level cis-eQTL (rs6471859) that regulates human DRG CA8 alternative splicing, producing a truncated 1,697bp transcript (e.g., CA8-204). Our functional genomic studies show the "G" allele at rs6471859 produces a cryptic 3'UTR splice site regulating expression of CA8-204. We developed constructs to study the expression and function of the naturally occurring CA8-204G transcript (G allele at rs6471859), CA8-204C (C allele at rs6471859 reversion mutation) and CA8-201 (full length transcript). CA8-204G transcript expression occurred predominantly in non-neuronal cells (HEK293), while CA8-204C expression was restricted to neuronal derived cells (NBL) in vitro. CA8-204G produced a stable truncated transcript in HEK293 cells that was barely detectable in NBL cells. We also show CA8-204 produces a stable peptide that inhibits pITPR1 and Ca++ release in HEK293 cells. These results imply homozygous G/G individuals at rs6471859, which are common in the general population, produce exclusively CA8-204G that is barely detectable in neuronal cells. CA8 null mutations that greatly impact neuronal functions are associated with severe forms of spinal cerebellar ataxia, and our data suggest G/G homozygotes should display a similar phenotype. To address this question, we show in vivo using AAV8-FLAG-CA8-204G and AAV8-V5-CA8-201 gene transfer delivered via intra-neural sciatic nerve injection (SN), that these viral constructs are able to transduce DRG cells and produce similar analgesic and anti-hyperalgesic responses to inflammatory pain. Immunohistochemistry (IHC) examinations of DRG tissues further show CA8-204G peptide is expressed in advillin expressing neuronal cells, but to a lesser extent compared to glial cells. These findings explain why G/G homozygotes that exclusively produce this truncated functional peptide in DRG evade a severe phenotype. These genomic studies significantly advance the literature regarding structure-function studies on CA8-ITPR1 critical to calcium signaling pathways, synaptic functioning, neuronal excitability and analgesic responses.
Learn More >Prevalence of migraine is high during the reproductive age. Although migraine often improves during pregnancy, the risk of adverse pregnancy, birth, neonatal, and neurological outcomes in mother and offspring remains poorly understood.
Learn More >To examine the longitudinal course of vasomotor symptoms (VMS) in women with a history of migraine, in comparison to women without a history of migraine disease.
Learn More >Investigation of pain requires measurements of nociceptive sensitivity and other pain-related behaviors. Recent studies have indicated the superiority of gait analysis over traditional evaluations (e.g., skin sensitivity and sciatic function index [SFI]) in detecting subtle improvements and deteriorations in animal models. Here, pain-related gait parameters, whose criteria include (1) alteration in pain models, (2) correlation with nociceptive threshold, and (3) normalization by analgesics, were identified in representative models of neuropathic pain (spared nerve injury: coordination data) and inflammatory pain (intraplantar complete Freund's adjuvant: both coordination and intensity data) in the DigiGait™ and CatWalk™ systems. DigiGait™ had advantages in fixed speed (controlled by treadmill) and dynamic SFI, while CatWalk™ excelled in intrinsic velocity, intensity data, and high-quality 3D images. Insights into the applicability of each system may provide guidance for selecting the appropriate gait imaging system for different animal models and optimization for future pain research.
Learn More >This controlled trial examined the benefit of a high-frequency transcutaneous electrical nerve stimulation (hfTENS) device (Quell ) for chronic low back pain (CLBP) patients. Thirty-five (N=35) participants were randomly assigned to use the device each day for 3 months (Experimental) and were compared with 33 subjects without the device (treatment-as-usual Control). All patients were instructed to complete baseline questionnaires and were assessed on thresholds of pressure pain and mechanical temporal summation as part of a standardized quantitative sensory test (QST) assessment. The subjects also uploaded smartphone applications (apps) for tracking use of the hfTENS and for daily pain assessment. Each participant completed weekly phone interviews, was prompted to complete daily pain app assessments, and was asked to repeat the baseline questionnaires again after 6 weeks and 3 months. Sixty percent of the subjects were female, 77.9% were Caucasian, and the average age was 46.2. Significant reductions in pain intensity (p<0.01) and activity interference (p<0.025) and significant improvements in pain catastrophizing (p<0.025) were noted in the Experimental subjects compared with the Controls. No group differences were found on depression, anxiety, or pain-related disability. Older subjects with a longer duration of pain tended to use the hfTENS more often. Subjects who showed greater sensitivity based on QST results revealed increased use of the hfTENS (p<0.025) and tended to believe that the hfTENS was more helpful in reducing their back pain, but these findings did not reach significance (p=0.09). Further trials designed to determine the mechanism of action of the hfTENS are needed. This article is protected by copyright. All rights reserved.
Learn More >No consensus exists for defining chronic preoperative opioid use. Most spine studies rely solely on opioid duration to stratify patients into preoperative risk categories.
Learn More >The phase III research evaluating migraine prophylaxis therapy (PREEMPT) protocol was developed in low-risk migraine patients. We studied longitudinal response to treatment in a sequential retrospective observational cohort to evaluate predictors of effectiveness in patients with multiple overlapping pain syndromes treated in a quaternary pain management clinic.
Learn More >Erenumab was effective and well tolerated in a pivotal clinical trial of episodic migraine that included subjects both naïve to, and those who had failed, previous preventives. Here we evaluated the efficacy and safety of erenumab (70 mg or 140 mg) versus placebo in the subgroup of patients who had previously failed preventive treatment(s): ≥1 or ≥2 prior failed migraine preventive categories, and in patients who had never failed.
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