Thalamic subfield iron accumulation after acute mild traumatic brain injury as a marker of future post-traumatic headache intensity.

OBJECTIVE: To explore alterations in thalamic subfield volume and iron accumulation in individuals with post-traumatic headache (PTH) relative to healthy controls. BACKGROUND: The thalamus plays a pivotal role in the pathomechanism of pain and headache, yet the role of the thalamus in PTH attributed to mild traumatic brain injury (mTBI) remains unclear. METHODS: A total of 107 participants underwent multimodal T1-weighted and T2* brain magnetic resonance imaging. Using a clinic-based observational study, thalamic subfield volume and thalamic iron accumulation were explored in 52 individuals with acute PTH (mean age = 41.3; standard deviation [SD] = 13.5), imaged on average 24 days post mTBI, and compared to 55 healthy controls (mean age = 38.3; SD = 11.7) without history of mTBI or migraine. Symptoms of mTBI and headache characteristics were assessed at baseline (0-59 days post mTBI) (n = 52) and 3 months later (n = 46) using the Symptom Evaluation of the Sports Concussion Assessment Tool (SCAT-5) and a detailed headache history questionnaire. RESULTS: Relative to controls, individuals with acute PTH had significantly less volume in the lateral geniculate nucleus (LGN) (mean volume: PTH = 254.1, SD = 43.4 vs. controls = 278.2, SD = 39.8; p = 0.003) as well as more iron deposition in the left LGN (PTH: T2* signal = 38.6, SD = 6.5 vs. controls: T2* signal = 45.3, SD = 2.3; p = 0.048). Correlations in individuals with PTH revealed a positive relationship between left LGN T2* iron deposition and SCAT-5 symptom severity score at baseline (r = -0.29, p = 0.019) and maximum headache intensity at the 3-month follow-up (r = -0.47, p = 0.002). CONCLUSION: Relative to healthy controls, individuals with acute PTH had less volume and higher iron deposition in the left LGN. Higher iron deposition in the left LGN might reflect mTBI severity and poor headache recovery.

T2* reduction in patients with acute post-traumatic headache.

OBJECTIVES: Although iron accumulation in pain-processing brain regions has been associated with repeated migraine attacks, brain structural changes associated with post-traumatic headache have yet to be elucidated. To determine whether iron accumulation is associated with acute post-traumatic headache, magnetic resonance transverse relaxation rates (T2*) associated with iron accumulation were investigated between individuals with acute post-traumatic headache attributed to mild traumatic brain injury and healthy controls. METHODS: Twenty individuals with acute post-traumatic headache and 20 age-matched healthy controls underwent 3T brain magnetic resonance imaging including quantitative T2* maps. T2* differences between individuals with post-traumatic headache versus healthy controls were compared using age-matched paired t-tests. Associations of T2* values with headache frequency and number of mild traumatic brain injuries were investigated using multiple linear regression in individuals with post-traumatic headache. Significance was determined using uncorrected p-value and cluster size threshold. RESULTS: Individuals with post-traumatic headache had lower T2* values compared to healthy controls in cortical (bilateral frontal, bilateral anterior and posterior cingulate, right postcentral, bilateral temporal, right supramarginal, right rolandic, left insula, left occipital, right parahippocampal), subcortical (left putamen, bilateral hippocampal) and brainstem regions (pons). Within post-traumatic headache subjects, multiple linear regression showed a negative association between T2* in the right inferior parietal/supramarginal regions and number of mild traumatic brain injuries and a negative association between T2* in bilateral cingulate, bilateral precuneus, bilateral supplementary motor areas, bilateral insula, right middle temporal and right lingual areas and headache frequency. CONCLUSIONS: Acute post-traumatic headache is associated with iron accumulation in multiple brain regions. Correlations with headache frequency and number of lifetime mild traumatic brain injuries suggest that iron accumulation is part of the pathophysiology or a marker of mild traumatic brain injury and post-traumatic headache.

CGRP monoclonal antibody prevents the loss of diffuse noxious inhibitory controls (DNIC) in a mouse model of post-traumatic headache.

AIM: Determine the role of calcitonin-gene related peptide in promoting post-traumatic headache and dysregulation of central pain modulation induced by mild traumatic brain injury in mice. METHODS: Mild traumatic brain injury was induced in lightly anesthetized male C57BL/6J mice by a weight drop onto a closed and unfixed skull, which allowed free head rotation after the impact. We first determined possible alterations in the diffuse noxious inhibitory controls, a measure of net descending pain inhibition called conditioned pain modulation in humans at day 2 following mild traumatic brain injury. Diffuse noxious inhibitory control was assessed as the latency to a thermally induced tail-flick that served as the test stimulus in the presence of right forepaw capsaicin injection that provided the conditioning stimulus. Post-traumatic headache-like behaviors were assessed by the development of cutaneous allodynia in the periorbital and hindpaw regions after mild traumatic brain injury. We then determined if intraperitoneal fremanezumab, an anti-calcitonin-gene related peptide monoclonal antibody or vehicle administered 2 h after sham or mild traumatic brain injury induction could alter cutaneous allodynia or diffuse noxious inhibitory control responses on day 2 post mild traumatic brain injury. RESULTS: In naïve and sham mice, capsaicin injection into the forepaw elevated the latency to tail-flick, reflecting the antinociceptive diffuse noxious inhibitory control response. Periorbital and hindpaw cutaneous allodynia, as well as a loss of diffuse noxious inhibitory control, was observed in mice 2 days after mild traumatic brain injury. Systemic treatment with fremanezumab blocked mild traumatic brain injury-induced cutaneous allodynia and prevented the loss of diffuse noxious inhibitory controls in mice subjected to a mild traumatic brain injury. INTERPRETATION: Sequestration of calcitonin-gene related peptide in the initial stages following mild traumatic brain injury blocked the acute allodynia that may reflect mild traumatic brain injury-related post-traumatic headache and, additionally, prevented the loss of net descending inhibition within central pain modulation pathways. As loss of conditioned pain modulation has been linked to multiple persistent pain conditions, dysregulation of descending modulatory pathways may contribute to the persistence of post-traumatic headache. Additionally, evaluation of the conditioned pain modulation/diffuse noxious inhibitory controls response may serve as a biomarker of vulnerability for chronic/persistent pain. These findings suggest that early anti-calcitonin-gene related peptide intervention has the potential to be effective both for the treatment of mild traumatic brain injury-induced post-traumatic headache, as well as inhibiting mechanisms that may promote post-traumatic headache persistence.

Headache Characteristics and Psychological Factors Associated with Functional Impairment in Individuals with Persistent Posttraumatic Headache.

OBJECTIVE: Persistent posttraumatic headache (PPTH), one of the most common symptoms following mild traumatic brain injury, is often associated with substantial functional disability. The objective of this study was to assess the contribution of demographics, headache characteristics, and psychological symptoms to disability associated with PPTH. METHODS: Participants completed the State-Trait Anxiety Inventory (STAI), the Beck Depression Inventory (BDI), the Pain Catastrophizing Scale (PCS), and the Migraine Disability Assessment (MIDAS) questionnaire. Two linear regression models were formulated to interrogate the relationships between 1) demographics and headache characteristics with the MIDAS questionnaire and 2) demographics, headache characteristics, and psychological symptoms with the MIDAS questionnaire. A two-way stepwise regression using the Akaike information criterion was performed to find a parsimonious model describing the relationships between demographics, headache characteristics, and psychological measures with the MIDAS questionnaire. RESULTS: Participants included 58 patients with PPTH and 39 healthy controls (HCs). The median MIDAS score among those with PPTH was 48.0 (first quartile [1Q] = 20.0, third quartile [3Q] = 92.0), indicative of severe disability. Compared with the HCs, those with PPTH had higher scores on the BDI, STAI, and PCS. Older age predicted lower MIDAS scores (age: B=-0.11, P<0.01), whereas higher headache frequency, greater headache intensity, and higher trait anxiety scores predicted higher MIDAS scores in individuals with PPTH (headache frequency: B=0.07, P<0.001; headache intensity: B=0.51, P=0.04; trait anxiety score: B=1.11, P=0.01). CONCLUSIONS: Individuals with PPTH had substantial psychological symptoms and headache-related disability. Disability was partially explained by age, headache frequency and intensity, and trait anxiety. Holistic management of patients with PPTH to address headaches and psychological symptoms might reduce headache-associated disability.

United States Patients' Perspective of Living With Migraine: Country-Specific Results From the Global "My Migraine Voice" Survey.

BACKGROUND: Migraine is associated with debilitating symptoms that can affect daily functioning. "My Migraine Voice" was a large, cross-sectional, multi-country online survey aimed at understanding disease burden directly from people with migraine. OBJECTIVE: This study reports on the social and economic impacts of migraine, specifically the impact on activities of daily living and the costs of migraine, from the point of view of people with migraine in the United States. METHODS: The online survey was administered to adults with a self-reported diagnosis of migraine who experienced 4 or more monthly migraine days each month for the previous 3 months. Prespecified screening quotas were used so that 90% of respondents reported current or past use of preventive migraine medication, 80% of whom switched treatment (ie, changed their prescribed preventive medication at least once). The remaining 10% were preventive treatment naïve (ie, never used any prescribed preventive medication). Burden of migraine on activities of daily living and caregivers (eg, functional limitations, fear of next migraine attack, sleep problems) and economic burden (eg, out-of-pocket costs, impact on work productivity using the validated work productivity and activity impairment questionnaire) reported by respondents from the United States are presented. Results are stratified by employment status, migraine frequency (chronic vs episodic migraine), and history of preventive treatment. RESULTS: Thousand hundred and one individuals with migraine from the United States responded to the survey. Respondents reported limitations completing daily activities during all migraine phases, including during the premonitory/aura and postdrome phases. Most (761/1101 (69%)) relied on family, friends, or others for help with daily tasks and reported being helped a median of 9 days (25th percentile 5 days, 75th percentile 15 days) within the last 3 months. Respondents with chronic migraine reported being helped for more days (median 10 days, 25th percentile 5 days, 75th percentile 23 days) in the last 3 months. Almost all (962/1101 (87%)) experienced sleep difficulties and 41% (448/1101) (48% (336/697) of those with 2 or more preventive treatment failures) were very or extremely fearful of a next migraine attack. Median (25th percentile, 75th percentile) monthly out-of-pocket costs of $90.00 ($30.00, $144.00) in doctor's fees (n = 504), $124.00 ($60.00, $234.00) in health insurance (n = 450), $40.00 ($20.00, $100.00) for prescriptions (n = 630), and $50.00 ($0.00, $100.00) for complementary therapies (n = 255) were reported. Those with 2 or more preventive treatment failures reported higher monthly out-of-pocket doctor fees (median $99.00 ($30.00, $150.00), n = 388). Among employed respondents (n = 661), migraine resulted in 22% absenteeism, 60% presenteeism, 65% work productivity loss, and 64% activity impairment. CONCLUSIONS: Migraine impacts individuals' activities of daily living, work-life, and financial status, especially individuals with high needs, namely those with 4 or more monthly migraine days and prior treatment failures. People with migraine are impaired during all migraine phases, experience fear of their next migraine attack and sleep difficulties, and pay substantial monthly out-of-pocket costs for migraine. Burden is even greater among those who have had 2 or more preventive treatment failures. Impacts of migraine extend beyond probands to caregivers who help people with migraine with daily tasks, employers who are affected by employee absenteeism, presenteeism, and reduced productivity, and society which is burdened by lost and reduced economic productivity and healthcare costs.

Altered Hypothalamic Region Covariance in Migraine and Cluster Headache: A Structural MRI Study.

OBJECTIVES: The hypothalamus plays a key role in both migraine and cluster headache (CH). As brain region-to-region structural correlations are believed to reflect structural and functional brain connectivity patterns, we assessed the structural covariance patterns between the volume of the hypothalamic region and vertex-by-vertex measurements of cortical thickness in patients with migraine and in those with CH relative to healthy controls (HC). METHODS: T1-weighted images were acquired on a 3T MRI scanner for a total of 59 subjects including 18 patients with CH (age: mean = 43.8, SD = 12.4), 19 with migraine (age: mean = 40.1, SD = 12.2), and 22 HCs (age: mean = 39.1, SD = 8.2). Imaging was collected between attacks (migraineurs) and during out-of-bout phases (CH). Data were post-processed using FreeSurfer version 6.0 and within-group correlations between hypothalamic region volume with cortical thickness were explored using a whole-brain vertex-wise linear model approach. Between-group differences in correlation slopes between hypothalamic region volume and vertex-by-vertex measurements of cortical thickness were interrogated using post-hoc comparisons. RESULTS: There were no significant between-group differences (migraine vs CH; migraine vs HC; or CH vs HC) for age, sex, total brain volume or volume of the left or right hypothalamic region. For each group, there were significant positive correlations (P < .01) between right and left hypothalamic region volumes with cortical thickness measurements. HC had significant positive correlations between hypothalamic region volume and cortical thickness over large portions of the superior and rostral medial frontal, orbitofrontal cortex and rostral anterior cingulate, and smaller clusters in the superior and middle temporal, posterior cingulate, fusiform, and precentral cortex. Post-hoc analysis showed significant differences in covariance patterns in those with migraine and CH relative to HC, with both migraine patients and CH having weaker structural covariance of hypothalamic region volume with frontal and temporal cortical thickness. CONCLUSION: Recent evidence suggests hypothalamic region connectivity to frontal and temporal areas to be relevant for regulating pain perception. Thus, the diminished structural covariance in migraineurs and CH might suggest abnormal functioning of the pain control circuitry and contribute to mechanisms underlying central sensitization and chronification of pain.

The American Registry for Migraine Research: Research Methods and Baseline Data for an Initial Patient Cohort.

BACKGROUND: The American Registry for Migraine Research (ARMR) is a multicenter, prospective, longitudinal patient registry, biorepository, and neuroimaging repository that collects clinical data, electronic health record (EHR) data, blood samples, and brain imaging data from individuals with migraine or other headache types. In this manuscript, we outline ARMR research methods and report baseline data describing an initial cohort of ARMR participants. METHODS: Adults with any International Classification of Headache Disorders (ICHD) diagnosis were prospectively enrolled from one of the 8 participating headache specialty centers. At baseline, ARMR participants complete web-based questionnaires, clinicians enter the participant's ICHD diagnoses, an optional blood specimen is collected, and neuroimaging data are uploaded to the ARMR neuroimaging repository. Participants maintain the ARMR daily headache diary longitudinally and follow-up questionnaires are completed by participants every 3 months. EHR data are integrated into the ARMR database from a subset of ARMR sites. Herein, we describe the ARMR methodology and report the summary data from ARMR participants who had, from February 2016 to May 2019, completed at least 1 baseline questionnaire from which data are reported in this manuscript. Descriptive statistics are used to provide an overview of patient's sociodemographics, headache diagnoses, headache characteristics, most bothersome symptoms other than headache, headache-related disability, comorbidities, and treatments. RESULTS: Data were available from 996 ARMR participants, enrolled from Mayo Clinic Arizona, Dartmouth-Hitchcock Medical Center, University of Utah, University of Colorado, Thomas Jefferson University, University of Texas Health Science Center at Houston, Georgetown University Medical Center, and DENT Neurological Institute. Among ARMR participants, 86.7% (n = 864) were female and the mean age at the time of enrollment was 48.6 years (±13.9; range 18-84). The most common provider-reported diagnosis was chronic migraine (n = 622), followed by migraine without aura (n = 327), migraine with aura (n = 196), and medication overuse headache (n = 65). Average headache frequency was 19.1 ± 9.2 days per month (n = 751), with 68% reporting at least 15 headache days per month. Sensitivity to light was the most frequent (n = 222) most bothersome symptom overall, other than headache, but when present, cognitive dysfunction was most frequently (n = 157) the most bothersome symptom other than headache. Average migraine disability assessment (MIDAS) score was 52 ± 49 (n = 760), (very severe headache-related disability); however, 17% of the ARMR population had MIDAS scores suggesting "no" or "mild" disability. The most common non-headache health issues were allergies (n = 364), back pain (n = 296), neck pain (n = 296), depression (n = 292), and anxiety (n = 278). Nearly 85% (n = 695) of patients were using preventive medications and 24.7% were using non-medication preventive therapy (eg, vitamins and neuromodulation). The most common preventive medication classes were neurotoxins, anticonvulsants, antidepressants, vitamins/supplements, and anticalcitonin gene-related peptide ligand or receptor-targeted monoclonal antibodies. Nearly 90% (n = 734) of ARMR participants was taking medications to treat migraine attacks, with the most common classes being triptans, non-steroidal anti-inflammatory drugs, antiemetics, acetaminophen, and combination analgesics. CONCLUSIONS: ARMR is a source of real-world patient data, biospecimens, and brain neuroimaging data that provides comprehensive insight into patients with migraine and other headache types being seen in headache specialty clinics in the United States. ARMR data will allow for longitudinal and advanced analytics that are expected to lead to a better characterization of patient heterogeneity, healthcare resource utilization, identification of endophenotypes, factors that predict treatment outcomes and clinical course, and ultimately advance the field toward precision headache medicine.

Preventive Therapy of Migraine.

PURPOSE OF REVIEW: This article reviews the preventive therapy of migraine, including indications, strategies for use, and available treatments. RECENT FINDINGS: Lifestyle modifications and migraine trigger avoidance are recommended as preventive measures for all individuals with migraine. The decision to recommend additional migraine preventive therapy should consider the frequency of migraine attacks and headaches, extent of migraine-associated disability, frequency of using acute migraine treatments and the responsiveness to such treatments, and patient preferences. Additional therapies include prescription medications, nutraceuticals, neurostimulation, and behavioral therapy. Considering evidence for efficacy and the risk of potential side effects and adverse events, treatments with the most favorable profiles include (in alphabetical order): amitriptyline, beta-blockers (several), biofeedback, candesartan, coenzyme Q10, cognitive-behavioral therapy, magnesium citrate, onabotulinumtoxinA (for chronic migraine only), relaxation therapy, riboflavin, and topiramate. In addition, erenumab, a calcitonin gene-related peptide (CGRP) receptor monoclonal antibody, received approval from the US Food and Drug Administration (FDA) for the prevention of migraine in May 2018. SUMMARY: Successful migraine preventive therapy reduces the frequency and burden of attacks while causing limited side effects. Individual treatment recommendations are determined based upon evidence for efficacy, side effect and adverse event profiles, medication interactions, patient comorbidity, costs, and patient preferences. Patients must be counseled on reasonable expectations for their preventive therapy and the importance of adhering to the recommended treatment plan for a period of time that is sufficient to determine outcomes.

Cluster headache.

Cluster headache is an excruciating, strictly one-sided pain syndrome with attacks that last between 15 minutes and 180 minutes and that are accompanied by marked ipsilateral cranial autonomic symptoms, such as lacrimation and conjunctival injection. The pain is so severe that female patients describe each attack as worse than childbirth. The past decade has seen remarkable progress in the understanding of the pathophysiological background of cluster headache and has implicated the brain, particularly the hypothalamus, as the generator of both the pain and the autonomic symptoms. Anatomical connections between the hypothalamus and the trigeminovascular system, as well as the parasympathetic nervous system, have also been implicated in cluster headache pathophysiology. The diagnosis of cluster headache involves excluding other primary headaches and secondary headaches and is based primarily on the patient's symptoms. Remarkable progress has been achieved in developing effective treatment options for single cluster attacks and in developing preventive measures, which include pharmacological therapies and neuromodulation.

Occipital Nerve Stimulation for Migraine: Update from Recent Multicenter Trials.

Occipital nerve stimulation (ONS) continues to be investigated for the treatment of refractory chronic migraine. Results from case series and from prospective, sham-controlled clinical trials remain inconclusive regarding the efficacy of ONS for migraine treatment. Safety and implantation techniques require improvements since rates of lead migration, infection, and persistent stimulator-related pain continue to be high. Existing data justify further ONS trials with carefully chosen primary outcome(s), adequate statistical power, and improved surgical techniques.

Neurostimulation for Treatment of Migraine and Cluster Headache.

OBJECTIVE: The objective of this narrative review is to summarize the current state of neurostimulation therapies for the treatment of migraine and/or cluster. METHODS: For this narrative review, publications were identified by searching PubMed using the search terms "migraine" or "cluster" combined with "vagal nerve stimulation," "transcranial magnetic stimulation," "supraorbital nerve stimulation," "sphenopalatine ganglion stimulation," "occipital nerve stimulation," "deep brain stimulation," "neurostimulation," or "neuromodulation." Publications were chosen based on the quality of data that were provided and their relevance to the chosen topics of interest for this review. Reference lists of chosen articles and the authors' own files were used to identify additional publications. Current clinical trials were identified by searching clinicaltrials.org. RESULTS AND CONCLUSIONS: Neurostimulation of the vagal nerve, supraorbital nerve, occipital nerve and sphenopalatine ganglion, transcranial magnetic stimulation (TMS), and deep brain stimulation have been investigated for the treatment of migraine and/or cluster. Whereas invasive methods of neurostimulation would be reserved for patients with very severe and treatment refractory migraine or cluster, noninvasive methods of stimulation might serve as useful adjuncts to more conventional therapies. Currently, transcutaneous supraorbital nerve stimulation is FDA approved and commercially available for migraine prevention and TMS is FDA approved for the treatment of migraine with aura. The potential utility of each type of neurostimulation has yet to be completely defined.

Cluster headache--acute and prophylactic therapy.

Cluster headache (CH) pain is the most severe of the primary headache syndromes. It is characterized by periodic attacks of strictly unilateral pain associated with ipsilateral cranial autonomic symptoms. The majority of patients have episodic CH, with cluster periods that typically occur in a circannual rhythm, while 10% suffer from the chronic form, with no significant remissions between cluster periods. Sumatriptan injection or oxygen inhalation is the first-line therapy for acute CH attacks, with the majority of patients responding to either treatment. The calcium channel blocker verapamil is the drug of choice for CH prevention. Other drugs that may be used for this purpose include lithium carbonate, topiramate, valproic acid, gabapentin, and baclofen. Transitional prophylaxis, most commonly using corticosteroids, helps to control the attacks at the beginning of a cluster period. Peripheral neural blockade is effective for short-term pain control. Recently, the therapeutic options for refractory CH patients have expanded with the emergence of both peripheral (mostly occipital nerve) and central (hypothalamic) neurostimulation. With the emergence of these novel treatments, the role of ablative surgery in CH has declined.

14th International Headache Congress: clinical highlights.

The 14th International Headache Congress was held in Philadelphia in September 2009. During the Congress, many important basic, translational, and patient-oriented research studies were presented. In this and an accompanying manuscript, the work that has been deemed to be among the most innovative and significant is summarized. This manuscript discusses the best clinical research, while the accompanying manuscript summarizes the top basic science research. Here, we provide background and summarize Congress presentations on novel agents for migraine treatment, botulinum toxin therapy for chronic migraine, new methods for administration of headache medications, and nerve stimulation for the treatment of medically refractory headaches.

Greater occipital nerve stimulation via the Bion microstimulator: implantation technique and stimulation parameters. Clinical trial: NCT00205894.

BACKGROUND: Millions of patients suffer from medically refractory and disabling primary headache disorders. This problem has led to a search for new and innovative treatment modalities, including neuromodulation of the occipital nerves. OBJECTIVES: The primary aim of this study is to describe an implantation technique for the Bion microstimulator and document stimulation parameters and stimulation maps after Bion placement adjacent to the greater occipital nerve. The secondary aim is to document outcome measures one year post-implant. DESIGN: Prospective, observational feasibility study. METHODS: Nine patients with medically refractory primary headache disorders participated in this study. Approximately 6 months after Bion insertion, stimulation parameters and maps were documented for all patients. At one year, outcome measures were collected including the Migraine Disability Assessment Score. RESULTS: At 6 months, the mean perception threshold was 0.47 mA, while the mean discomfort threshold was 6.8 mA (stimulation range 0.47-6.8 mA). The mean paresthesia threshold was 1.64 mA and the mean usage range was 16.0. There were no major complications reported such as device migration, infection, or erosion. One patient stopped using her Bion before the 12-month follow-up visit. At one year, 7 of the 8 patients were judged as having obtained fair or better results in terms of reduction of disability; 5 patients had greater than a 90% reduction in disability. LIMITATIONS: Small, heterogeneous patient population without control group. Not blinded or randomized. CONCLUSION: The Bion can be successfully inserted adjacent to the greater occipital nerve in an effort to treat refractory primary headache disorders. This microstimulator may provide effective occipital stimulation and headache control while minimizing the risks associated with percutaneous or paddle leads implanted subcutaneously in the occipital region.

Neurostimulation for primary headache disorders.

Neurostimulation has emerged as a potential treatment option for patients with chronic, disabling, intractable primary headache disorders. Although safety and efficacy data are limited in quantity, there is accumulating experience with the use of peripheral nerve stimulation for the treatment of intractable occipital neuralgia, cluster headache, migraine, and less common headache disorders. Deep brain stimulation has been used to treat intractable chronic cluster headache and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing. This article discusses the theorized mechanisms of action of these novel treatment modalities and summarizes current knowledge regarding safety and efficacy of neurostimulation for the treatment of headache.

Occipital nerve stimulation for medically intractable headache.

There is an unmet need, and thus a continued search, for effective treatments for patients with chronic daily headache who do not respond to or tolerate conventional therapies. Recent interest has focused on the use of occipital nerve stimulation (ONS) to treat patients with chronic, disabling headaches who are not adequately controlled by usual therapies. A small but growing body of evidence supports the use of ONS for the treatment of intractable headache. Electrical stimulation of the occipital nerve has both peripheral and central nervous system effects that modulate nociception. The exact role for ONS will evolve as our understandings of its physiologic effects, efficacy, and safety grow.