Dodick, David W.

ImportanceExposure to repetitive head impacts (RHI) is associated with increased risk for neurodegeneration. Accumulation of toxic proteins due to impaired brain clearance is suspected to play a role.ObjectiveTo investigate whether perivascular space (PVS) volume is associated with lifetime exposure to RHI in individuals at risk for RHI-associated neurodegeneration.Design, Setting, and ParticipantsThis cross-sectional study was part of the Diagnostics, Imaging, and Genetics Network for the Objective Study and Evaluation of Chronic Traumatic Encephalopathy (DIAGNOSE CTE) Research Project, a 7-year multicenter study consisting of 4 US study sites. Data were collected from September 2016 to February 2020 and analyses were performed between May 2021 and October 2023. After controlling for magnetic resonance image (MRI) and processing quality, former American football players and unexposed asymptomatic control participants were included in analyses.ExposurePrior exposure to RHI while participating in American football was estimated using the 3 cumulative head impact indices (CHII-G, linear acceleration; CHII-R, rotational acceleration; and CHII, number of head impacts).Main Outcomes and MeasuresIndividual PVS volume was calculated in the white matter of structural MRI. Cognitive impairment was based on neuropsychological assessment. Linear regression models were used to assess associations of PVS volume with neuropsychological assessments in former American football players. All analyses were adjusted for confounders associated with PVS volume.ResultsAnalyses included 224 participants (median [IQR] age, 57 [51-65] years), with 170 male former football players (114 former professional athletes, 56 former collegiate athletes) and 54 male unexposed control participants. Former football players had larger PVS volume compared with the unexposed group (mean difference, 0.28 [95% CI, 0.00-0.56]; P = .05). Within the football group, PVS volume was associated with higher CHII-R (β = 2.71 × 10−8 [95% CI, 0.50 × 10−8 to 4.93 × 10−8]; P = .03) and CHII-G (β = 2.24 × 10−6 [95% CI, 0.35 × 10−6 to 4.13 × 10−6]; P = .03). Larger PVS volume was also associated with worse performance on cognitive functioning in former American football players (β = −0.74 [95% CI, −1.35 to −0.13]; P = .04).Conclusions and RelevanceThese findings suggest that impaired perivascular brain clearance, as indicated by larger PVS volume, may contribute to the association observed between RHI exposure and neurodegeneration.

Abstract Objective To identify and disseminate research priorities for the headache field that should be areas of research focus during the next 10 years. Background Establishing research priorities helps focus and synergize the work of headache investigators, allowing them to reach the most important research goals more efficiently and completely. Methods The Headache Research Priorities organizing and executive committees and working group chairs led a multistakeholder and international group of experts to develop headache research priorities. The research priorities were developed and reviewed by clinicians, scientists, people with headache, representatives from headache organizations, health‐care industry representatives, and the public. Priorities were revised and finalized after receiving feedback from members of the research priorities working groups and after a public comment period. Results Twenty‐five research priorities across eight categories were identified: human models, animal models, pathophysiology, diagnosis and management, treatment, inequities and disparities, research workforce development, and quality of life. The priorities address research models and methods, development and optimization of outcome measures and endpoints, pain and non‐pain symptoms of primary and secondary headaches, investigations into mechanisms underlying headache attacks and chronification of headache disorders, treatment optimization, research workforce recruitment, development, expansion, and support, and inequities and disparities in the headache field. The priorities are focused enough that they help to guide headache research and broad enough that they are widely applicable to multiple headache types and various research methods. Conclusions These research priorities serve as guidance for headache investigators when planning their research studies and as benchmarks by which the headache field can measure its progress over time. These priorities will need updating as research goals are met and new priorities arise.

Tools used for the identification, evaluation, and monitoring of concussion have not been sufficiently studied in youth or real-world settings. Normative and reliability data on sideline concussion assessment measures in the youth athlete population is needed. Pre-season normative data for 515 athletes (93.5% male) aged 5 to 16 on the Standardized Assessment of Concussion (SAC/SAC-Child), modified Balance Errors Scoring System (mBESS), Timed Tandem Gait (TTG), and the King–Devick Test (KDT) are provided. A total of 212 non-injured athletes repeated the measures post-season to assess test–retest reliability. Mean performance on the SAC-C, mBESS, TTG, and KDT tended to improve with age. KDT was the only measure that demonstrated good to excellent stability across age ranges (ICC = 0.758 to 0.941). Concentration was the only SAC/SAC-C subtest to demonstrate moderate test–retest stability (ICC = 0.503 to 0.706). TTG demonstrated moderate to good (ICC = 0.666 to 0.811) reliability. mBESS demonstrated poor to moderate reliability (ICC = −0.309 to 0.651). Commonly used measures of concussion vary regarding test–retest reliability in youth. The data support the use of at least annual sport concussion baseline assessments in the pediatric population to account for the evolution in performance as the child ages. Understanding the variation in the stability and the evolution of baseline performance will enable improved identification of possible injury.

Abstract The small molecule calcitonin gene–related peptide receptor antagonists (gepants) are the only drug class with medicines indicated for both the acute and preventive treatment of migraine. Given this dual capacity to both treat and prevent, along with their favorable tolerability profiles and lack of an association with medication‐overuse headache, headache specialists have begun to use gepants in ways that transcend the traditional categories of acute and preventive treatment. One approach, called situational prevention , directs patients to treat during the interictal phase, before symptoms develop, in situations of increased risk for migraine attacks. Herein, we present three patients to illustrate scenarios of gepant use for situational prevention. In each case, a gepant was started in anticipation of a period of increased headache probability (vulnerability) and continued for a duration of 1 day to 5 consecutive days. Although this approach may expose patients to medication when headache may not have developed, the tolerability and safety profile and preventive effect of gepants may represent a feasible approach for some patients. Situational prevention is an emerging strategy for managing migraine before symptoms develop in individuals who can identify periods when the probability of headache is high. This paper is intended to increase awareness of this strategy and stimulate future randomized, placebo‐controlled trials to rigorously assess this strategy.

Abstract Objective To characterize the long‐term (56‐week) benefits of continuous onabotulinumtoxinA treatment response in individuals with chronic migraine (CM) who achieved reduction to <15 headache days/month with treatment. Background There are limited data exploring reductions in monthly headache days to levels consistent with episodic migraine among those experiencing CM. Understanding the impact of sustained preventive treatment response in CM can provide important information about the impact of successful therapy. Methods The two Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy trials of onabotulinumtoxinA in adults included a 24‐week, randomized, double‐blind, placebo‐controlled phase and a 32‐week open‐label phase. Data were pooled to determine proportions of individuals with <15 headache days/month while on treatment during several time periods in the double‐blind phase (Weeks 21–24; any 12 consecutive weeks; Weeks 13–24) and the entire study (Weeks 53–56; any 12 consecutive weeks; any 4‐week period). We assessed the long‐term impact on mean monthly headache days and changes from baseline on the six‐item Headache Impact Test (HIT‐6) and Migraine‐Specific Quality of Life questionnaire version 2.1 (MSQv2.1). Results We analyzed 1384 participants with chronic migraine (double‐blind: onabotulinumtoxinA, n = 688; placebo, n = 696; open‐label: n = 688 [onabotulinumtoxinA]). The discontinuation rates prior to the completion of the full 56‐week treatment period for onabotulinumtoxinA and placebo were 25.4% ( n = 175) and 29.3% ( n = 204), respectively. During Weeks 13–24 of the double‐blind phase, significantly more onabotulinumtoxinA‐treated (386/688 [56.1%]) than placebo‐treated (342/696 [49.1%]) individuals had <15 headache days/month ( p = 0.010), with fewer monthly headache days for onabotulinumtoxinA versus placebo responders. The proportions of participants achieving <15 monthly headache days with onabotulinumtoxinA were 60.9% (419/688) at Weeks 25–56, 81.1% (558/688) at Weeks 53–56, and 79.4% (546/688) during any consecutive 12‐week period. Mean changes from baseline on the HIT‐6 and MSQv2.1 questionnaire surpassed within‐group minimal important difference thresholds in all periods. At Week 24, onabotulinumtoxinA‐treated participants who achieved <15 monthly headache days during Weeks 21–24 had a greater mean HIT‐6 score reduction (−6.5 vs. −1.4) and greater mean MSQv2.1 Role‐Function Restrictive score improvements (21.3 vs. 6.4) than those who did not achieve <15 monthly headache days during the same period. Conclusions Participants who achieved <15 monthly headache days with onabotulinumtoxinA treatment achieved meaningful benefits in headache‐related disability and migraine‐specific quality of life compared with those who remained at or above the 15–monthly headache days threshold. Sustained benefits observed over 56 weeks support long‐term onabotulinumtoxinA use for the prevention of CM.

Abstract Background Chronic migraine exerts substantial negative impacts on daily functioning. Efforts to manage impaired functioning may result in medication overuse, which contributes to the worsening profile and chronification of migraine. The Migraine Functional Impact Questionnaire (MFIQ) is a recently developed measure assessing the impact of migraine on physical, social, and emotional function. Objective The objective of this analysis was to assess changes in MFIQ scores following initiation or modification of migraine preventive medication and determine if changes in function are associated with changes in other aspects of migraine burden, such as headache frequency, headache intensity, and symptoms of anxiety and depression. Methods This is a secondary analysis of data from the Medication Overuse Treatment Strategy (MOTS) trial, a prospective pragmatic clinical trial that investigated two treatment strategies for those with chronic migraine and medication overuse. Data from both treatment arms were pooled and analyzed using a pre–post design. Prior to and 12 weeks following initiation or modification of migraine preventive medication, participants completed a series of questionnaires that captured migraine characteristics, medication use, migraine‐related physical impairment (MFIQ), anxiety (Generalized Anxiety Disorder‐7), and depression (Patient Health Questionnaire 9 [PHQ‐9]) symptoms. Changes from baseline in all measures were assessed using the paired t ‐test. Relationships between changes in MFIQ scores and other measures were assessed using linear regression. Multivariable modeling was performed to determine which additional variables contributed to the change in MFIQ beyond that already explained by an individual variable. Model terms were selected by using elastic net regularization. Only those participants who completed the baseline and 12‐week MFIQ were included in this analysis. Results Of the 537 patients, 88.2% were female, and the average age was 45 years (standard deviation 13). The mean frequency of days with moderate‐to‐severe headache improved 39.2% from 13.5 per 30 days at baseline to 8.1 per 30 days at week 12. The mean MFIQ Usual Activities Global score improved by 15.0 points (on a 100‐point scale). All five domains (Usual Activities Global, Usual Activities, Social Function, Emotional Function, Physical Function) of the MFIQ improved by a mean of at least 13.0 points. Changes in PHQ‐9 score, followed by changes in headache frequency, had the strongest associations with change in all domains of the MFIQ. Conclusions The negative impact of chronic migraine with medication overuse on physical, social, and emotional functioning substantially lessened following initiation or modification of migraine preventive medication. Improved functioning, as measured by the MFIQ, was most strongly associated with reductions in depression scores and headache frequency, highlighting the importance of recognizing and monitoring changes in depressive symptoms, in addition to headache frequency and functional impairment, when evaluating response to preventive medications.

Objective While a substantial body of research describes the disabling impacts of migraine attacks, less research has described the impacts of migraine on physical functioning between migraine attacks. The objective of this study is to describe physical impairment during and between migraine attacks as a dimension of burden experienced by people living with chronic migraine. Methods The physical impairment domain of the Migraine Physical Function Impact Diary was recorded in headache diaries from the Medication Overuse Treatment Strategy trial. Days with moderate to severe headache were used to approximate migraine attacks. Factor analysis and regression analysis were used to describe associations between migraine and physical impairment. Results 77,662 headache diary entries from 720 participants were analyzed, including 25,414 days with moderate to severe headache, 19,149 days with mild headache, and 33,099 days with no headache. Mean physical impairment score was 41.5 (SD = 26.1) on days with moderate to severe headache, 12.8 (SD = 15.0) on days with mild headache, and 5.2 (SD = 13.1) on days with no headache. Physical impairment on days with mild headache and days with no headache was significantly associated with days since last moderate to severe headache, physical impairment with last moderate to severe headache, mild headache (compared to no headache), depression, hypersensitivities and cranial autonomic symptoms. Conclusions Physical impairment occurs on migraine and non-migraine days. Study participants with frequent headaches, symptoms of depression, hypersensitivities and cranial autonomic symptoms experience physical impairment at a higher rate on days with no headache and days with mild headache. Clinical Trial Registration: ClinicalTrials.gov (NCT02764320)