Background.-Cluster headache (CH), the most common trigeminal autonomic cephalalgia, is an extremely debilitating primary headache disorder that is often not optimally treated. New evidence-based treatment guidelines for CH will assist clinicians with identifying and choosing among current treatment options.Objectives.-In this systematic review we appraise the available evidence for the acute and prophylactic treatment of CH, and provide an update of the 2010 American Academy of Neurology (AAN) endorsed systematic review.Methods.-Medline, PubMed, and EMBASE databases were searched for double-blind, randomized controlled trials that investigated treatments of CH in adults. Exclusion and inclusion criteria were identical to those utilized in the 2010 AAN systematic review.Results and Recommendations.-For acute treatment, sumatriptan subcutaneous, zolmitriptan nasal spray, and high flow oxygen remain the treatments with a Level A recommendation. Since the 2010 review, a study of sphenopalatine ganglion stimulation was added to the current guideline and has been administered a Level B recommendation for acute treatment. For prophylactic therapy, previously there were no treatments that were administered a Level A recommendation. For the current guidelines, suboccipital steroid injections have emerged as the only treatment to receive a Level A recommendation with the addition of a second Class I study. Other newly evaluated treatments since the 2010 guidelines have been given a Level B recommendation (negative study: deep brain stimulation), a Level C recommendation (positive study: warfarin; negative studies: cimetidine/chlorpheniramine, candesartan), or a Level U recommendation (frovatriptan).Conclusions.-This AHS guideline can be utilized for understanding which therapies have superiority to placebo or sham treatment in the management of CH. In clinical practice, these recommendations should be considered in concert with other variables including safety, side effects, patient preferences, clinician experience, cost, and the invasiveness of the intervention. Given the lack of Class I evidence and Level A recommendations, particularly for a number of commonly used preventive therapies, further studies are warranted to demonstrate safety and efficacy for established and emerging therapies.

Background.-Erenumab, a calcitonin gene-related peptide (CGRP) receptor monoclonal antibody, has been well tolerated with good efficacy for the preventive treatment of episodic and chronic migraine in phase 2 and phase 3 clinical trials. Limited post-market observations are available to validate these findings in a real-world tertiary headache clinic population with complex comorbidities and refractory migraine. Objective.-The goal of this study is to demonstrate the real-world performance of erenumab among patients in a tertiary care headache clinic by describing patient selection, experience, and clinical characteristics after 6 months of erenumab therapy. Methods.-A retrospective, exploratory, observational study was conducted on patients receiving at least 1 erenumab injection (70 or 140 mg). Baseline data obtained by chart review and telephone calls were compared to 6-month follow-up telephone calls. The primary outcome was the reduction in self-reported headache days per month at baseline compared to 6 months for those with complete 6-month data. The significance level was set at P < .05. Secondary analyses explored the distribution of headache severity, responder rates, Migraine Disability Assessment scores, adverse effects, ineffective preventives, comorbidities, wearing-off, and discontinuation. Results.-Of the 101 patients who consented to participate, 89.1% (90/101) were women, and the mean age of all patients was 49 years (range, 19-80 years). At baseline, 94.1% (95/101) of patients had chronic migraine, 5.0% (5/101) had episodic migraine, and 18.8% (19/101) had medication overuse headache. The mean (SD) number of baseline headache and migraine days per month for the entire cohort were 24.3 (8.2) and 18.2 (9.3) days, respectively. Participants had numerous comorbidities and had tried a mean of 11.2 unique oral medications and 4.8 unique medication categories before receiving erenumab, including 83.2% (84/101) who had also received onabotulinumtoxinA. Six-month post-erenumab follow-up data were available for 42.6% (43/101) of participants. For these 43 participants, the number of headache days per month decreased significantly by 6.5 days from a baseline mean (SD) of 24.8 (6.47) days to 18.3 (12) days at 6-month follow-up (P < .001); similarly, the monthly migraine days decreased significantly by 8.4 days from a baseline mean of 19.1 (9.3) days to 10.7 days at 6-month follow-up (P < .001). The 50% responder rate was 34.9% (15/43) for monthly headache days and 54.8% (23/43) for monthly migraine days. Of all 101 participants, 28 (27.7%) discontinued erenumab, primarily because it was ineffective (39.3%, 11/28) or because of adverse effects (42.9%, 12/28). Conclusion.-This post-market observational study of patient experience describes response to erenumab in a real-world tertiary headache clinic with a complex patient population. Overall, these complex patients had a significant positive clinical response to erenumab, but with high rates of discontinuation. This study also noted a 1-week wearing-off resp...

Huntington's disease (HD) is characterized by loss of striatal gamma-aminobutyric acid (GABA)ergic medium-sized spiny projection neurons (MSSNs), whereas some classes of striatal interneurons are relatively spared. Striatal interneurons provide most of the inhibitory synaptic input to MSSNs and use GABA as their neurotransmitter. We reported previously alterations in glutamatergic synaptic activity in the R6/2 and R6/1 mouse models of HD. In the present study, we used whole-cell voltage clamp recordings to examine GABAergic synaptic currents in MSSNs from striatal slices in these two mouse models compared to those in age-matched control littermates. The frequency of spontaneous GABAergic synaptic currents was increased significantly in MSSNs from R6/2 transgenics starting around 5-7 weeks (when the overt behavioral phenotype begins) and continuing in 9-14-week-old mice. A similar increase was observed in 12-15-month-old R6/1 transgenics. Bath application of brain-derived neurotrophic factor, which is downregulated in HD, significantly reduced the frequency of spontaneous GABAergic synaptic currents in MSSNs from R6/2 but not control mice at 9-14 weeks. Increased GABA current densities also occurred in acutely isolated MSSNs from R6/2 animals. Immunofluorescence demonstrated increased expression of the ubiquitous alpha1 subunit of GABA(A) receptors in MSSNs from R6/2 animals. These results indicate that increases in spontaneous GABAergic synaptic currents and postsynaptic receptor function occur in parallel to progressive decreases in glutamatergic inputs to MSSNs. In conjunction, both changes will severely alter striatal outputs to target areas involved in the control of movement.

ObjectiveTo evaluate the efficacy and tolerability of single pulse transcranial magnetic stimulation (sTMS) for the preventive treatment of migraine.BackgroundsTMS was originally developed for the acute treatment of migraine with aura. Open label experience has suggested a preventive benefit. The objective of this trial was to evaluate the efficacy and tolerability of sTMS for migraine prevention.MethodsThe eNeura SpringTMS Post-Market Observational U.S. Study of Migraine (ESPOUSE) Study was a multicenter, prospective, open label, observational study. From December 2014 to March 2016, patients with migraine (n = 263) were consented to complete a 1-month baseline headache diary followed by 3 months of treatment. The treatment protocol consisted of preventive (four pulses twice daily) and acute (three pulses repeated up to three times for each attack) treatment. Patients reported daily headache status, medication use, and device use with a monthly headache diary. The primary endpoint, mean reduction of headache days compared to baseline, was measured over the 28-day period during weeks 9 to 12. The primary endpoint was compared to a statistically-derived placebo estimate (performance goal). Secondary endpoints included: 50% responder rate, acute headache medication consumption, HIT-6, and mean reduction in total headache days from baseline of any intensity.ResultsOf a total of 263 consented subjects, 229 completed a baseline diary, and 220 were found to be eligible based on the number of headache days. The device was assigned to 217 subjects (Safety Data Set) and 132 were included in the intention to treat Full Analysis Set. For the primary endpoint, there was a −2.75 ± 0.40 mean reduction of headache days from baseline (9.06 days) compared to the performance goal (−0.63 days) (p < 0.0001). The 50% responder rate of 46% (95% CI 37%, 56%) was also significantly higher (p < 0.0001) than the performance goal (20%). There was a reduction of −2.93 (5.24) days of acute medication use, headache impact measured by HIT-6, −3.1 (6.4) (p < 0.0001), and total headache days of any intensity −3.16 days (5.21) compared to the performance goal (−0.63 days) (p < 0.0001). The most common adverse events were lightheadedness (3.7%), tingling (3.2%), and tinnitus (3.2%). There were no serious adverse events.ConclusionsThis open label study suggests that sTMS may be an effective, well-tolerated treatment option for migraine prevention.Trial registration numberNCT02357381

ObjectiveTo determine the potential impact of erenumab, a human anti‐calcitonin gene‐related peptide (CGRP) receptor monoclonal antibody, on total exercise time (TET), time to exercise‐induced angina, and ST depression in a double‐blind, placebo‐controlled study in patients with stable angina due to documented coronary artery disease.BackgroundThe relative importance of the CGRP receptor pathway during myocardial ischemia has not been established.MethodsAn exercise treadmill test was conducted following a single IV infusion of erenumab 140 mg or placebo. The primary endpoint was the change from baseline in exercise duration as measured by TET with a noninferiority margin of −90 seconds. Safety follow‐up visits occurred through week 12. Eighty‐eight participants were included in the analysis.ResultsLS mean (SE) change in TET was −2.9 [14.8] seconds in the erenumab group and 8.1 [14.4] seconds in placebo; adjusted mean (90% CI) treatment difference was −11.0 (–44.9, 22.9) seconds. The CI lower bound (–44.9 sec) did not reach pre‐defined non‐inferiority margin of −90 seconds, demonstrating that TET change from baseline in the erenumab group was non‐inferior to placebo. There was no difference in time to exercise‐induced angina in erenumab and placebo groups (median [90% CI] time of 500 [420, 540] vs 508 [405, 572] seconds; hazard ratio [90% CI]: 1.11 [0.73, 1.69], P = .69) or time to onset of ≥1 mm ST‐segment depression (median [90% CI] time of 407 [380, 443] vs 420 [409,480] seconds; hazard ratio [95% CI]: 1.14 [0.76, 1.69], P = .59). Adverse events were reported by 27% and 32% of patients in erenumab and placebo groups.ConclusionsErenumab did not adversely affect exercise time in a high cardiovascular risk population of patients, supporting that inhibition of the canonical CGRP receptor does not worsen myocardial ischemia.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that affects primarily the striatum and cerebral cortex. A search for the factors that increase the vulnerability of striatal neurons will lead to a better understanding of the pathological cascades of this disease. A current hypothesis for neurodegeneration of striatal medium-sized spiny neurons in HD is an alteration in N-methyl-D-aspartate (NMDA) receptor function. In the present study we examined electrophysiological properties of NMDA receptors in the R6/2 transgenic mouse model. These animals express exon 1 of the human HD gene and present an overt behavioral phenotype at about 5 weeks of age. Whole-cell voltage clamp recordings from acutely dissociated striatal neurons were obtained from three different age groups of transgenic mice (15, 21, and 40 days old) and their littermate controls (WT). In transgenic animals, two groups of neurons were found with respect to NMDA and Mg2+ sensitivity. One group of R6/2 cells displayed responses similar to those of WT, whereas the other showed increased responses to NMDA and decreased Mg2+ sensitivity. These cells were encountered in all age groups. The abnormal sensitivity to NMDA and Mg2+ indicates that NMDA receptor alterations occur very early in development and suggest the presence of constitutively abnormal NMDA receptors. These alterations may contribute to an enhancement of NMDA responses at hyperpolarized membrane potentials that may be a key factor in striatal neuronal dysfunction.

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The subunit composition of glutamate receptors affects their functional properties, and could contribute to abnormal electrophysiology in pediatric cortical dysplasia (CD). We examined electrophysiological responses and subunit assembly of N-methyl-D-aspartate (NMDA) receptors in acutely dissociated normal-appearing pyramidal and cytomegalic neurons from CD tissue and normal-appearing pyramidal neurons from non-CD tissue. In most cytomegalic and approximately 30% of normal-appearing pyramidal neurons from CD tissue, NMDA currents showed decreased Mg(2+) sensitivity compared with neurons from non-CD tissue. Ifenprodil had less effect in CD compared with non-CD neurons, indicating a functional loss of NR2B subunits. NMDA-evoked current density was decreased in cytomegalic compared with normal-appearing neurons. Single-cell reverse transcriptase polymerase chain reaction showed that all non-CD neurons expressed NR2B subunit mRNA. By comparison, 22% of pyramidal neurons in CD tissue lacked NR2B mRNA. Immunofluorescence showed a decrease in NR2B subunit expression in cytomegalic neurons and a subset of normal-appearing pyramidal neurons from CD tissue. Taken together, these results demonstrate the presence of NMDA receptors with altered subunit composition and Mg(2+) sensitivity that could contribute to functional abnormalities in CD.