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Hypothalamus is a crucial deep brain area that is responsible for the integration and coordination of various brain functions. The altered perfusion of hypothalamus during headache caused by medication-overuse headache (MOH) was previously unknown. In the current study, the altered perfusion of hypothalamic subregions in MOH patients was investigated using state-of-the-art 3D pseudo-continuous arterial spin labeling (PCASL) MR imaging. In this study, 29 normal controls subjects (NCs) and 29 MOH patients underwent 3D PCASL and brain structural MR imaging. The hypothalamus was automatically segmented into 10 subunits and the volume of each subunit was automatically determined using Freesurfer software (v7.4.1). All segmented hypothalamic subunits were converted to individual hypothalamic subunit masks. The cerebral blood flow (CBF) images were coregistered with the raw brain structural images and resliced. The CBF value of each hypothalamic subunit was extracted from the warped CBF images. The volume and CBF value of each hypothalamic subunit were analyzed using the independent sample T test and Mann-Whitney U test, receiver operating characteristic (ROC) curve analysis, and Pearson and Spearman correlation analysis. Hypothalamic subunits with significantly decreased perfusion were located in the left posterior, left tubular superior, right anterior-inferior, right tubular inferior, right tubular superior, right posterior subunit and the entire right hypothalamus [CBF value for MOH vs NC (mL/100 g·min): 48.41 ± 6.75 vs 54.08 ± 11.47, 44.44 ± 4.79 vs 48.11 ± 7.73, 41.49 (32.90, 61.46) vs 49.38 ± 10.47, 46.62 ± 7.04 vs 53.90 ± 11.75, 42.12 ± 5.74 vs 47.02 ± 9.99, 42.79 ± 5.15 vs 47.93 ± 10.48 and 43.58 ± 5.06 vs 48.65 ± 9.33, respectively] in MOH compared to NC (P < 0.05). ROC analysis for these positive subunits revealed that area under the curve was 0.658-0.693, and ROC curve for left posterior subunit had the highest specificity of 93.10% while the entire right hypothalamus had the highest sensitivity of 72.41%. Further correlation analysis showed that the CBF value of the left posterior, right anterior-inferior, right tubular superior, whole right hypothalamus presented significantly negative correlation with Hamilton Depression Scale (HAMD) score (P < 0.05). Hypoperfusion of hypothalamic subunits may contribute to the understanding of MOH pathogenesis, and the 3D PCASL could be considered as a potential diagnostic and assessment tool for MOH., (© 2024. The Author(s).)

Medication overuse headache (MOH), the development or worsening of chronic headache resulting from frequent and excessive intake of medications used for acute treatment of headache, is a common secondary headache disorder and is associated with significant personal and societal burdens. The plausible physiologic mechanism is that chronic exposure to acute care migraine treatment leads to suppression of endogenous antinociceptive systems, consequently facilitating the trigeminal nociceptive process via up-regulation of the calcitonin gene-related peptide (CGRP) system. Recognizing and preventing its development is an integral aspect of migraine management, as medication overuse is a modifiable risk factor in the progression from episodic to chronic migraine. Over the years, MOH has been difficult to treat and has generated much controversy. Ongoing debates exist over the diagnostic criteria and treatment strategies, particularly regarding the roles of formal detoxification and preventive treatment. The arrival of the anti-CGRP monoclonal antibodies has also challenged our views of MOH and its treatment. This review outlines the evolution of MOH diagnostic criteria, presents the current understanding of MOH pathogenesis and discusses the debates over its development and treatment. Data on the efficacy of anti-CGRP monoclonal antibodies in the setting of medication overuse is also presented. These results indicate that patients with medication overuse, who are treated with these new medications, may not need to be detoxified in order to treat MOH. In light of these developments, it is likely that in the future MOH will be more readily diagnosed and treatment will result in better outcomes.

Objective: To describe headache characteristics, medication use, disability, and quality of life in a large patient cohort from the United States who have chronic migraine (CM) and medication overuse headache (MOH)., Methods: In all, 610 adult patients were enrolled into the Medication Overuse Treatment Strategy trial from 34 healthcare clinics, including headache specialty, general neurology, and primary care clinics. Descriptive statistics characterize baseline demographics, headache characteristics, medication use, disability (Headache Impact Test 6 [HIT-6] and Migraine Functional Impact Questionnaire [MFIQ]), pain interference (PROMIS Pain Interference), and quality of life (EQ-5D-5L). Relationships with headache frequency were assessed., Results: Mean age was 45 years (SD 13) and 531/608 (87.3%) were females. Mean headache days per 30 was 24.3 (SD 5.5), including 13.6 (SD 7.1) with moderate to severe headache. Daily headaches were reported by 36.1% (219/607) of patients. Acute headache medications were used on 21.5 (SD 7.5) per 30 days. The most commonly overused medications were simple analgesics (378/607, 62% of patients), combination analgesics (246/607, 41%), and triptans (128/607, 21%). HIT-6, MFIQ, PROMIS Pain Interference, and EQ-5D-5L scores demonstrated substantial negative impact from CM with MOH on patient functioning and quality of life. Higher headache frequency was associated with more moderate-severe headache days, more frequent acute headache medication use, greater headache-related disability, and lower quality of life. Only 272/606 (44.9%) were taking migraine preventive medication., Conclusions: CM with MOH is associated with a large burden on patients in the United States. Higher headache frequency is associated with greater impact on functioning, pain interference, and quality of life., (© 2021 American Headache Society.)

Background: Stabbing headache (SH) is considered as a pure primary headache, but according to a few clinical observations it could also be secondary. Over the past decades, we have been observing the complaint of SH in patients with intracranial vascular and neoplastic lesions., Objective: To describe a series of patients with intracranial lesions who experienced SH., Methods: This is a cross-sectional, retrospective study of 34 patients with intracranial lesions associated with SH, admitted at Hospital das Clínicas, Federal University of Pernambuco, Brazil., Results: In this series of 34 patients [29 women, 44 ± 12 years (mean ± SD)] with secondary SH, the causes were intracranial neoplasms (n = 31), cerebral aneurysms (n = 2), or arteriovenous malformation (n = 1). Pituitary tumor (n = 18), meningioma (n = 6), and vestibular schwannomas (n = 4) were the most prevalent types of intracranial neoplasms. All these lesions had intimate contact with the dura mater, including an oligodendroglioma, the only intra-axial tumor in the series. A characteristic in the secondary SH is the crescendo pattern (12/34, 35%), progressing from infrequent attacks to recurrent crises occurring several times a day. The SH lasted from 5 days to 60 months (15 ± 18 months, mean ± SD) until the correct diagnosis [16/34 (47%) of the patients ≤6 months]. The SH was triggered by the movement of the head (5/34, 15%) or Valsalva maneuver (1/34). After surgery, suppression of the SH was observed. In a few of the patients to whom dexamethasone was prescribed, the SH subsided within a few days., Conclusion: This study was able to identify clinical red flags associated with intracranial lesions and secondary SH, for example, recent onset of SH, exclusively unilateral (ipsilateral) at the same location, crescendo pattern, triggered by head movements, or Valsalva maneuver., (© 2021 American Headache Society.)

Objectives: Little evidence is available on the role of transcranial direct current stimulation (tDCS) in patients affected by chronic migraine (CM) and medication overuse headache (MOH). We aim to investigate the effects of tDCS in patients with CM and MOH as well as its role on brain activity., Methods: Twenty patients with CM and MOH were hospitalized for a 7-day detoxification treatment. Upon admission, patients were randomly assigned to anodal tDCS or sham stimulation delivered over the primary motor cortex contralateral to the prevalent migraine pain side every day for 5 days. Clinical data were recorded at baseline (T0), after 1 month (T2) and 6 months (T3). EEG recording was performed at T0, at the end of the tDCS/Sham treatment, and at T2., Results: At T2 and T3, we found a significant reduction in monthly migraine days (p = 0.001), which were more pronounced in the tDCS group when compared to the sham group (p = 0.016). At T2, we found a significant increase of alpha rhythm in occipital leads, which was significantly higher in tDCS group when compared to sham group., Conclusions: tDCS showed adjuvant effects to detoxification in the management of patients with CM and MOH. The EEG recording showed a significant potentiation of alpha rhythm, which may represent a correlate of the underlying changes in cortico-thalamic connections., Significance: This study suggests a possible role for tDCS in the treatment of CM and MOH. The observed clinical improvement is coupled with a potentiation of EEG alpha rhythm., Competing Interests: Declaration of Competing Interest CT received honoraria for the participation in advisory boards or for oral presentations from: Allergan, ElectroCore, Eli-Lilly, Novartis, and Teva. CT has no ownership interest and does not own stocks of any pharmaceutical company. CT serves as Chief Section Editor of Frontiers in Neurology—Section Headache Medicine and Facial Pain and on the editorial board of The Journal of Headache and Pain. GS received honoraria for the participation in advisory boards or for oral presentations from: Eli-Lilly and Novartis. The remaining authors have no conflicts of interest., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: To summarize for the trainee audience the possible mechanisms of headache in patients with COVID-19 as well as to outline the impact of the pandemic on patients with headache disorders and headache medicine in clinical practice., Background: COVID-19 is a global pandemic caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2, of which a large subset of patients features neurological symptoms, commonly headache. The virus is highly contagious and is, therefore, changing clinical practice by forcing limitations on in-person visits and procedural treatments, more quickly shifting toward the widespread adaptation of telemedicine services., Design/results: We review what is currently known about the pathophysiology of COVID-19 and how it relates to possible mechanisms of headache, including indirect, potential direct, and secondary causes. Alternative options for the treatment of patients with headache disorders and the use of telemedicine are also explored., Conclusions: Limited information exists regarding the mechanisms and timing of headache in patients with COVID-19, though causes relate to plausible direct viral invasion of the nervous system as well as the cytokine release syndrome. Though headache care in the COVID-19 era requires alterations, the improved preventive treatment options now available and evidence for feasibility and safety of telemedicine well positions clinicians to take care of such patients, especially in the COVID-19 epicenter of New York City., (© 2020 American Headache Society.)

Multisensory processing can be assessed by measuring susceptibility to crossmodal illusions such as the Sound-Induced Flash Illusion (SIFI). When a single flash is accompanied by 2 or more beeps, it is perceived as multiple flashes (fission illusion); conversely, a fusion illusion is experienced when more flashes are matched with a single beep, leading to the perception of a single flash. Such illusory perceptions are associated to crossmodal changes in visual cortical excitability. Indeed, increasing occipital cortical excitability, by means of transcranial electrical currents, disrupts the SIFI (ie, fission illusion). Similarly, a reduced fission illusion was shown in patients with episodic migraine, especially during the attack, in agreement with the pathophysiological model of cortical hyperexcitability of this disease. If episodic migraine patients present with reduced SIFI especially during the attack, we hypothesize that chronic migraine (CM) patients should consistently report less illusory effects than healthy controls; drugs intake could also affect SIFI. On such a basis, we studied the proneness to SIFI in CM patients (n = 63), including 52 patients with Medication Overuse Headache (MOH), compared to 24 healthy controls. All migraine patients showed reduced fission phenomena than controls (P < .0001). Triptan MOH patients (n = 23) presented significantly less fission effects than other CM groups (P = .008). This exploratory study suggests that CM - both with and without medication overuse - is associated to a higher visual cortical responsiveness which causes deficit of multisensorial processing, as assessed by the SIFI. PERSPECTIVE: This observational study shows reduced susceptibility to the SIFI in CM, confirming and extending previous results in episodic migraine. MOH contributes to this phenomenon, especially in case of triptans., (Copyright © 2020 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: Medication-overuse headache (MOH) is a common debilitating neurological disorder, with a prevalence of 1% to 7% in general population. It affects more than 60 million people worldwide and provokes substantial burden. Despite that, most practitioners don't know MOH. This review aims at presenting MOH clinical features, pathophysiology insights, and recent knowledge and guidance regarding treatments., Areas Covered: A literature search in the major medical databases including the terms 'medication overuse headache,' 'chronic daily headache,' 'chronic migraine,' 'symptomatic medication overuse' and others, published between 1990 and 2020, was carried out., Expert Commentary: Primary headache sufferers such as migraineurs and tension-type headache patients may increase the headache frequency and induce the transition from episodic to chronic forms, as well as develop MOH, in the presence of medication overuse. There is evidence of structural and functional changes in some areas of the brain, which may identify those likely to respond or not to treatments. Despite the geographical differences and lack of consensus regarding approaches, to educate the patients about reducing medication intake, to withdraw overused medications and to start prophylaxis in some sufferers are crucial steps. Emerging treatments as monoclonal antibodies to migraine may result in better adherence and tolerability profiles as well as outcomes.

This article reviews the disorders of thunderclap, cough, exertional and sexual headache. These are a group of paroxysmal and precipitated headaches, which often occur in bouts with prolonged remissions. Indometacin seems to be the most effective preventative. Each can occur in primary and secondary form. Thunderclap headache is the most frequently reported headache syndrome associated with a secondary pathology. Discussed are the complexities of whether all patients with thunderclap headache should have further investigation if timely computerised tomography is normal and, the relevance of abnormal imaging in these disorders, differentiating what is deemed to be secondary and managing the pain.

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., (© 2019 American Headache Society.)

Aim: This basic review is intended to summarize the current knowledge of methemoglobinemia as an important cause of secondary headache with the hope of generating a growing interest in studying this phenomenon., Background: We describe the pathological underpinnings of headaches generated by hypoxia. Possible mechanisms include cerebral vasodilation-associated stretching of the vessel nociceptors, sensitization of perivascular nociceptors mediated by nitric oxide, cerebral calcitonin gene-related peptide, activation of the cyclic adenosine monophosphate pathway, cortical spreading depression, disruption of the blood-brain barrier, and neurogenic inflammation. We review the clinical features, pathophysiology, and management of methemoglobinemia. We conducted a literature review of reports of symptomatic methemoglobinemia with headache. In addition, we describe a case report of a patient who presented with an acute onset of severe holocranial headache associated with rapidly progressive perioral paresthesia, cyanosis in lips and hands, nausea, and mild dyspnea on exertion. These features can be misinterpreted as an acute attack of migraine with pain-related hyperventilation syndrome and anxiety leading to clinically detrimental delay in the management of the progressive hypoxia. Her symptoms resolved following treatment with methylene blue. The complex relationship of migraine and hypoxia-related headaches is also reviewed. We propose that methemoglobinemia-associated headaches are possibly generated by stretching of the nociceptor nerve endings during cerebral vasodilation and hypoxia-mediated oxidative stress., Conclusions: The case highlights the need to broaden the formulated differential diagnosis of an acute onset severe holocranial headache and pay careful attention to other signs and symptoms that may provide hints on potential mechanism(s) for secondary headaches. We provide justification for the need to incorporate "Headache attributed to Methemoglobinemia" as a subtype under the section "Headache attributed to hypoxia and/or hypercapnia" of the International Classification of Headache Disorders to support clinical decision making., (© 2019 American Headache Society.)

Medication overuse headache (MOH), previously known as analgesic abuse headache or medication misuse headaches, is a common form of chronic headache disorder that has a detrimental impact on health and society. Although it has been widely accepted that overusing abortive medications is paradoxically the cause of MOH and drug discontinuation is the treatment of choice, ongoing debates exist as to whether drug consumption per se is the cause or consequence of headache chronification. Certain features in MOH such as their compulsive drug-seeking behavior, withdrawal headaches and high relapse rates share similarities with drug dependence, suggesting that there might be common underlying biological and psychobehavioral mechanisms. In this regard, this article will discuss the updated evidence and current debates on the possible biobehavioral overlap between MOH and drug dependence. To begin with, we will discuss whether MOH has characteristics of substance dependence based on standard psychiatry diagnostic criteria and other widely used dependence scales. Recent epidemiological studies underscoring common psychiatric comorbidities between the two disorders will also be presented. Although both demonstrate seemingly distinct personality traits, recent studies revealed similar decision-making impairment from a cognitive perspective, indicating the presence of a maladaptive reward system in both disorders. In addition, emerging imaging studies also support this notion by showing reversible morphological and functional brain changes related to the mesocorticolimbic reward circuitry in MOH, with a strong resemblance to those in addiction. Finally, an increased familial risk for drug dependence and genetic association with dopaminergic and drug dependence molecular pathways in MOH also support a possible link between MOH and addiction. Understanding the role of dependence in MOH will have a great impact on disease management as this will provide the missing piece of the puzzle in current therapeutic strategies., (© 2020 Elsevier B.V. All rights reserved.)

Background: The pathogenesis of medication overuse headache (MOH) involves hyperexcitability of cortical and trigeminal neurons. Derangement of the brainstem modulating system, especially raphe nuclei may contribute to this hyperexcitability. The present study aimed to investigate the involvement of the nucleus raphe magnus (NRM) in the development of cortical and trigeminal hyperexcitability in a rat model of MOH., Results: Chronic treatment with acetaminophen increased the frequency of cortical spreading depression (CSD) and the number of c-Fos-immunoreactive (Fos-IR) neurons in the trigeminal nucleus caudalis (TNC). In the control group, muscimol microinjected into the NRM increased significantly the frequency of CSD-evoked direct current shift and Fos-IR neurons in the TNC. This facilitating effect was not found in rats with chronic acetaminophen exposure. In a model of migraine induced by intravenous systemic infusion of nitroglycerin (NTG), rats with chronic exposure to acetaminophen exhibited significantly more frequent neuronal firing in the TNC and greater Fos-IR than those without the acetaminophen treatment. Muscimol microinjection increased neuronal firing in the TNC in control rats, but not in acetaminophen-treated rats. The number of Fos-IR cells in TNC was not changed significantly., Conclusion: Chronic exposure to acetaminophen alters the function of the NRM contributing to cortical hyperexcitability and facilitating trigeminal nociception.

Regular or frequent use of analgesics and acute antimigraine drugs can increase the frequency of headache, and induce the transition from episodic to chronic headache or medication overuse headache. The 1-year prevalence of this condition in the general population is between 1% and 2%. Medication overuse headache is more common in women and in people with comorbid depression, anxiety, and other chronic pain conditions. Treatment of medication overuse headache has three components. First, patients need education and counselling to reduce the intake of medication for acute headache attacks. Second, some patients benefit from drug withdrawal (discontinuation of the overused medication). Finally, preventive drug therapy and non-medical prevention might be necessary in patients at onset of treatment or in patients who do not respond to the first two steps. The optimal therapeutic approach requires validation in controlled trials., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: To study the effects of a standard acute medication withdrawal program on short-term cortical plasticity mechanisms in patients with medication overuse headache (MOH)., Methods: Thirteen patients with MOH and 16 healthy volunteers underwent repetitive transcranial magnetic stimulation (rTMS) over the left motor cortex; in patients with MOH, recordings were performed before and after a 3-week medication withdrawal program. Ten trains of 10 stimuli each (120% resting motor threshold) were delivered at 1 Hz or 5 Hz in two separate sessions in a randomised order. Motor evoked potential (MEP) amplitudes were measured from the right first dorsal interosseous muscle and the slope of the linear regression line from the first to the tenth stimuli was calculated for each participant., Results: All subjects exhibited MEP amplitude inhibition in response to 1 Hz rTMS. Alternatively, the 5-Hz trains of rTMS inhibited rather than potentiated MEP amplitudes in patients with MOH. The physiological potentiating effect of 5 Hz rTMS on MEP amplitudes was restored after drug withdrawal and in proportion with the percentage reduction in monthly headache days in patients with MOH., Conclusions: The results suggest that acute medication withdrawal normalises brain responses in patients with MOH. Clinical improvements after medication withdrawal may reflect the reversal of neurophysiological dysfunction. Accordingly, medication withdrawal should be offered to patients with MOH as early as possible in order to prevent the development of more pronounced alterations in brain plasticity.

Background: Loss of conditioned pain modulation/diffuse noxious inhibitory controls has been demonstrated in patients with migraine and medication overuse headache. We hypothesized that exposure to acute migraine medications may lead to dysregulation of central pain modulatory circuits that could be revealed by evaluating diffuse noxious inhibitory controls and that prior noxious stimulus is required for a loss of the diffuse noxious inhibitory control response in rats exposed to these medications., Methods: Rats were "primed" by continuous infusion of morphine or one of two doses of sumatriptan. Diffuse noxious inhibitory control was evaluated at the end of drug-priming (day 7) and again after sensory thresholds returned to baseline (day 21). The Randall-Selitto hindpaw pressure test was used as the test stimulus and forepaw capsaicin injection served as the conditioning stimulus., Results: Morphine-primed rats showed opioid-induced hyperalgesia accompanied by a loss of diffuse noxious inhibitory controls on day 7. Sumatriptan-primed rats did not develop hyperalgesia or loss of diffuse noxious inhibitory controls on day 7. Morphine-primed and high-dose sumatriptan-primed rats only had a loss of diffuse noxious inhibitory control on day 21 if they received a capsaicin injection on day 7., Conclusions: Prolonged exposure to migraine treatments followed by an acute nociceptive stimulation caused long-lasting alterations in descending pain modulation, shown by a loss of diffuse noxious inhibitory controls. Morphine was more detrimental than sumatriptan, consistent with clinical observations of higher medication overuse headache risk with opioids. These data suggest a mechanism of medication overuse headache by which migraine medications combined with repeated episodes of pain may amplify the consequences of nociceptor activation and increase the probability of future migraine attacks as well as risk of medication overuse headache.

Objective: To study the effects of trains of repetitive transcranial magnetic stimulation (rTMS) over the motor cortex in patients with chronic migraine (CM) with or without medication overuse (MOH)., Subjects and Methods: Thirty-two patients (CM [n = 16]; MOH [n = 16]) and 16 healthy volunteers (HVs) underwent rTMS recording. Ten trains of 10 stimuli each (120% resting motor threshold) were applied over the left motor cortex at 1 Hz or 5 Hz in random order. The amplitude of motor evoked potential (MEP) was evaluated from electromyographic recording in the first dorsal interosseous muscle. The slope of the linear regression line for the 10 stimuli for each participant was calculated using normalized data., Results: rTMS-1 Hz had a normal depressive effect on MEP amplitude in all groups. rTMS-5 Hz depressed instead of potentiating MEP amplitudes in MOH patients, with a significantly different response from that in HVs and CM patients. The slope of the linear regression of MEP amplitudes was negatively correlated with pain intensity in CM patients, and with the duration of overuse headache in MOH patients., Conclusions: This different plastic behaviour suggests that MOH and CM, despite exhibiting a similar clinical phenotype, have different neurophysiological learning processes, probably related to different pathophysiological mechanisms of migraine chronification.

We attempted to gather information on the pathogenesis of medication-overuse headache, as well as on the neurochemical mechanisms through which symptomatic medication overuse concurs to headache chronification. Transcriptional profiles were therefore evaluated as an index of the homeostasis of the trigeminovascular system in the trigeminal ganglion of female rats exposed for 1 month to daily oral doses of eletriptan or indomethacin. We report that both drug treatments change trigeminal ganglion gene expression to a similar extend. Of note, qualitative transcriptomic analysis shows that eletriptan and indomethacin prompt nearly identical, increased expression of genes coding for proteins involved in migraine pathogenesis and central pain sensitization such as neuropeptides, their cognate receptors, prostanoid, and nitric oxide-synthesizing enzymes, as well as TRP channels. These genes, however, were not affected in thoracic dorsal root ganglia. Of note, lowering of orofacial nociceptive thresholds, as well as forepaw hyperalgesia occurred in both indomethacin- and eletriptan-treated rats. Our study reveals that chronic rat exposure to 2 acute headache medications with completely different mechanisms of action prompts pain sensitization with highly similar induction of pronociceptive genes selectively within the trigeminal ganglion. Data further our understanding of medication-overuse headache pathogenesis and provide hints for specific mechanism-based treatment options.

Objective To investigate the intranetwork resting state fMRI connectivity within the Salience Network of chronic migraine with and without medication overuse headache. Methods We compared 351 pairs of intranetwork connectivity in chronic migraine (n = 13) and chronic migraine with medication overuse headache (n = 16) compared to matched controls, and between each chronic migraine subgroup. Results Compared to controls, 17 pairs of intranetwork connections in chronic migraine and 27 pairs in chronic migraine with medication overuse headache were decreased. When comparing chronic migraine with medication overuse headache versus chronic migraine, connectivity between bilateral extended amygdala, and between paracingulate to right ventral tegmental area/substantia nigra were decreased in chronic migraine (chronic migraine < chronic migraine with medication overuse headache). Connectivity between left dorsolateral prefrontal cortex to bilateral ventral striatum/pallidum, to bilateral dorsal anterior cingulate cortex; left anterior prefrontal cortex to contralateral orbitofrontal insula; and left ventral striatum/pallidum to ipsilateral supplementary motor area (SMA)/preSMA were decreased in chronic migraine with medication overuse headache (chronic migraine with medication overuse headache < chronic migraine). Conclusion Both chronic migraine subgroups had shared intranetwork connectivity abnormality, however, each subgroup had unique pattern of disruption within the salience network. The results suggest that the aberrant assignment of salience to external and internal stimuli plays an important role in chronic migraine and chronic migraine with medication overuse headache interictally, mostly involving mesolimbic pathways (especially bilateral extended amygdala) in chronic migraine, and prefrontal-subcortical limbic pathways in chronic migraine with medication overuse headache.

Background: Therapeutic management of Chronic Migraine (CM), often associated with Medication Overuse Headache (MOH), is chiefly empirical, as no biomarker predicting or correlating with clinical efficacy is available to address therapeutic choices. The present study searched for neurophysiological correlates of Greater Occipital Nerve Block (GON-B) effects in CM., Methods: We recruited 17 CM women, of whom 12 with MOH, and 19 healthy volunteers (HV). Patients had no preventive treatment since at least 3 months. After a 30-day baseline, they received a bilateral betamethasone-lidocaine GON-B of which the therapeutic effect was assessed 1 month later. Habituation of visual evoked potentials (VEP) and intensity dependence of auditory evoked potentials (IDAP) were recorded before and 1 week after the GON-B., Results: At baseline, CM patients had a VEP habituation not different from HV, but a steeper IDAP value than HV (p = 0.01), suggestive of a lower serotonergic tone. GON-B significantly reduced the number of total headache days per month (- 34.9%; p = 0.003). Eight out 17CM patients reversed to episodic migraine and medication overuse resolved in 11 out of 12 patients. One week after the GON-B VEP habituation became lacking respect to baseline (p = 0.01) and to that of HV (p = 0.02) like in episodic migraine, while the IDAP slope significantly flattened (p < 0.0001). GON-B-induced reduction in headache days positively correlated with IDAP slope decrease (rho = 0.51, p = 0.03)., Conclusions: GON-B may be effective in the treatment of CM, with or without MOH. The pre-treatment IDAP increase is compatible with a weak central serotonergic tone, which is strengthened after GON-B, suggesting that serotonergic mechanisms may play a role in CM and its reversion to episodic migraine. Since the degree of post-treatment IDAP decrease is correlated with clinical improvement, IDAP might be potentially useful as an early predictor of GON-B efficacy.

The potential of [INCREMENT]-tetrahydrocannabinol (THC) as a treatment for migraine depends on antinociceptive efficacy with repeated administration. Although morphine has good antinociceptive efficacy, repeated administration causes medication overuse headache (MOH) - a condition in which the intensity/frequency of migraine increases. The present study compared the effect of repeated morphine or THC administration on the magnitude and duration of migraine-like pain induced by a microinjection of allyl isothiocyanate (AITC) onto the dura mater of female rats. Acute administration of THC or morphine prevented AITC-induced depression of wheel running. This antinociception was maintained in rats treated repeatedly with THC, but not following repeated administration of morphine. Moreover, repeated morphine, but not THC administration, extended the duration of AITC-induced depression of wheel running. These data indicate that tolerance and MOH develop rapidly to morphine administration. The lack of tolerance and MOH to THC indicates that THC may be an especially effective long-term treatment against migraine.

Introduction: Headaches are a common occurrence in childhood and adolescence. Most children presenting with a chief complaint of headache have a self-limited infectious disorder or primary headache syndrome that should not require extensive workup., Purpose of Review: Differentiating these conditions from other more serious causes of headache in children can sometimes be difficult. This article aims to provide information regarding "red flags" that should indicate a need for concern for disorders that require more urgent evaluation., Recent Findings: Long-held beliefs about specific "red flags" that have been analyzed in recent years as to their validity and new criteria for the diagnosis of idiopathic intracranial hypertension have been elaborated based on study. These publications are reviewed in this article. Knowledge of past and current literature on secondary headache in children, combined with thorough history taking and examination, should help determine when there is concern for a serious secondary cause for headache in children and adolescents and direct workup.

Background: Although risk factors for medication-overuse headache have been identified within the general population, most studies have neglected clinical samples. The present study examined the relative and combined associations of these factors with medication-overuse headache in a sample of US adults seeking treatment for primary headache disorders., Methods: Treatment-seeking headache patients provided data on demographics, headache variables, psychiatric variables, use of headache medications, and use of other prescription medications and substances. A classification tree selection strategy was utilized within this cross-sectional study to differentiate between those with and without medication-overuse headache, and a final multivariable model assessed their combined utility., Results: Forty-three of 164 participants (26.2%) met diagnostic criteria for medication-overuse headache. Relative to non-medication-overuse headache participants, participants with medication-overuse headache reported greater headache-related disability (odds ratio = 1.09, 95% confidence interval = 1.01-1.18), escape and avoidance responses indicative of fear of pain (odds ratio = 1.07, 95% confidence interval = 1.00-1.15), and use of combination medications for headache (odds ratio = 3.10, 95% confidence interval = 1.51-6.36). The final multivariable model differentiated well between the 2 groups (area under the receiver operating characteristic curve = .78; 95% confidence interval = .71-.86)., Conclusions: Items that assess headache-related disability, use of combination medications, and fear of pain help identify patients who are currently overusing acute headache medications and may serve as indicators of treatment progress. Future studies should apply similar analytic approaches longitudinally to identify headache sufferers at risk for medication-overuse headache prior to headache progression., (© 2018 American Headache Society.)

Background This study investigated the effects of medication overuse and withdrawal on modulation of pain processing in women with migraine. Temporal summation of laser-evoked thermal pain was used to measure the effects of conditioned pain modulation. Methods 36 female participants (12 healthy volunteers, 12 with episodic migraine and 12 with medication overuse headache) were included in a two session protocol. Medication overuse headache subjects were also tested three weeks after medication overuse headache withdrawal. Mechanical and laser-evoked thermal pain thresholds were measured on the back of the non-dominant hand where, later, temporal summation of laser-evoked thermal pain to repetitive thermal stimuli was elicited for 30 min, at an intensity producing moderate pain. Between the 10 th and 20 th minutes, the contralateral foot was immersed into a water bath at a not painful (30℃) or painfully cold (8℃; conditioned pain modulation) temperature. Results Episodic migraine, medication overuse headache and medication overuse headache withdrawal were associated with an increase in extracephalic temporal summation of laser-evoked thermal pain as compared to healthy volunteer subjects, while there was no alteration of laser-evoked thermal and mechanical extracephalic pain thresholds in these subjects. Conditioned pain modulation was highly efficient in temporal summation of laser-evoked thermal pain in healthy volunteer subjects, with a solid post-effect (reduction of pain). Conditioned pain modulation was still present, but reduced, in episodic migraine. By contrast, conditioned pain modulation was normal in medication overuse headache and strongly reduced in medication overuse headache withdrawal. Furthermore, in medication overuse headache withdrawal, the post-effect was no longer a decrease, but a facilitation of pain. Conclusions These data show that a decrease in conditioned pain modulation does not underlie medication overuse headache in women. On the contrary, medication overuse reinstated conditioned pain modulation in female migraine patients. They also identify different phenotypes of pain modulation in migraine patients. Registration number N° 2008-A00471-54.

Objective: In this pilot study, the purpose is to investigate if a series of sphenopalatine ganglion (SPG) blockade treatments modulate the functional connectivity within the salience and central executive network (CEN) in chronic migraine with medication overuse headaches (CM w/MOH )., Background: Using intranasal local anesthesia to block the SPG for the treatment of various headache disorders has been employed in clinical practice since the early 1900s. However, the exact mechanism of how SPG modulate resting state intrinsic functional brain networks connectivity remains to be elucidated. This pilot study seeks to understand the resting state connectivity changes in salience and CENs, with emphasis on the mesocorticolimbic systems, before and after a series of SPG block treatments., Methods: Using fMRI, resting state connectivity was derived from predefined networks of nodes (regions of interests) for the salience (27 nodes, 351 connections) and CENs (17 nodes, 136 connections). After treatments, a paired samples t-test (with 10,000 permutations to correct for multiple comparison) was used to evaluate changes in the intranetwork resting state functional connectivity within the salience and executive networks, as well as the overall network connectivity strength., Results: When comparing connectivity strength at baseline to that at the end of treatment in our cohort of 10 CM w/MOH participants, there were several connections within the salience (n = 9) and executive (n = 8) networks that were significantly improved. Within the salience network, improved connectivity was observed between the prefrontal cortex and various regions of the insula, basal ganglia, motor, and frontal cortex. Additionally, changes in connectivity were observed between regions of the temporal cortex with the basal ganglia and supramarginal gyrus. Within the CEN, improved connectivity was observed between the prefrontal cortex and regions of the anterior thalamus, caudate, and frontal cortex. After treatment, the overall CEN connectivity was significantly improved (Baseline 0.00 ± 0.08; 6 weeks 0.03 ± 0.09, P = .01); however, the overall salience network connectivity was not significantly improved (Baseline -0.01 ± 0.10; 6 weeks 0.01 ± 0.12, P = .26). Additionally, after treatment, there was a significant reduction in the number of moderate/severe headache days per month (Baseline 21.1 ± 6.6; 6 weeks 11.2 ± 6.5, P < .001), HIT-6 (Baseline 66.1 ± 2.6; 6 weeks 60.2 ± 3.6, P < .001), and PHQ-9 (Baseline 12.4 ± 5.7; 6 weeks 6.1 ± 3.6, P = .008) scores., Conclusion: In this longitudinal fMRI study, we observed improved functional connectivity within both networks, primarily involving connectivity between regions of the prefrontal cortex and limbic (cortical-limbic) structures, and between different cortical (cortical-cortical) regions after a series of repetitive SPG blockades. The overall CEN strength was also improved. Our results suggest that recurrent parasympathetic inhibition via SPG is associated with improved functional connectivity in brain regions critical to pain processing in CM w/MOH ., (© 2018 American Headache Society.)

Objective: To investigate the headache characteristics and clinical features of elderly migraine patients at a tertiary headache center., Methods: We retrospectively reviewed 239 records of migraine patients, over the age of 64 at the first visit, who had migraine as defined by the International Classification of Headache Disorders 3rd edition (beta version) from 2006 to 2015 based on the Marseille registry at Timone Hospital., Results: 13.8% (33/239) patients had migraine with aura only, 13.0% (31/239) had both diagnoses. Of the patients who presented with migraine with aura, 13.4% (32/239) presented with aura without headache. Unilateral pain location was reported by 58.6% (140/239) of patients and the throbbing type of pain was present in 50.2% (120/239) of our study group. Photo- and phonophobia were observed in 77.4% (185/239) and 79.5% (190/239) of patients. Seventy-nine out of 239 (30.1%) patients were found to have probable medication overuse. Within this group, 31.65% (25/79) overused triptan and 70.9% (56/79) overused combination analgesics. We found higher frequencies of migraine for patients whose age at onset of migraine was younger than 18 years, and low frequency migraine was reported more frequently in the later onset group (P = .0357)., Discussion: We assess the headache characteristics of elderly migraine patients who were seen at our tertiary headache center and report the high frequency of probable medication overuse headache in this study group. Finally, we suggest that age of onset is an important factor in the clinical profile of these patients., (© 2017 American Headache Society.)

Competing Interests: Competing interests: None declared.

- Medication-overuse headache is a highly prevalent disorder with a major impact on the quality of life.- Medication-overuse headache is defined as headache on ≥ 15 days per month with overuse of acute headache medication for ≥ 3 months. We talk about overuse in case of intake of simple analgesics on ≥ 15 days per month or triptans or combinations of analgesics on ≥ 10 days per month.- The underlying type of headache is usually migraine or tension-type headache.- One of the possible underlying mechanisms of medication-overuse headache is changed sensitivity as a consequence of central sensitisation.- The initial treatment is detoxification of the headache medication. The preferred detoxification method is outpatient, abrupt withdrawal of all acute-headache medication and caffeine-containing products. Essential for successful detoxification is education about the reasons for detoxification, the expected course and the subsequent treatment.

Background: Acute headache is one of the most frequent neurological symptoms in pregnant women. The early diagnosis of underlying secondary conditions has a major influence on patient outcome, especially in emergency settings. However, at the time being no well-established guideline for diagnostic evaluation of acute headache during pregnancy exists. In this study, we aimed to characterize acute headache in pregnant women concerning demographic, clinical, and diagnostic features, and to determine predictors of secondary headache., Methods: We analysed retrospectively the data of 151 pregnant women receiving neurological consultation due to acute headache at the Charité Berlin between 2010 and 2016. To assess risk factors for secondary headache in these patients we compared multiple anamnestic and clinical features of the primary and secondary headache group., Results: 57.6% of the patients were diagnosed with primary headache, most common migraine and tension type headache. Concerning secondary headaches, the most common aetiologies were infections (29.7%) and hypertensive disorders (22.0%). The primary and secondary headache group were similar in most anamnestic and clinical features. In multivariate logistic regression analysis, secondary headache history [OR 6.6; 95% CI 1.3-33.1], elevated blood pressure [OR 7.2; 95% CI 2.3-22.6], fever [OR 12.1; 95% CI 1.3-111.0] and abnormal neurological examination [OR 9.9; 95% CI 2.7-36.3] represented independent predictors for secondary headache. Regarding additional diagnostic procedures, abnormal thrombocytes, GOT, GPT and CRP, proteinuria, pathologic results of lumbar puncture and neuroimaging were associated with secondary headache., Conclusions: Secondary headache disorders are common during pregnancy, occurring in over one third of acute headache cases receiving neurological consultation. Most anamnestic and clinical features may not allow a clear distinction between primary and secondary headaches. Clinicians should pay attention to the presence of secondary headache history, elevated blood pressure, fever and abnormal findings in the neurological examination. Additional investigations, including laboratory tests and neuroimaging, are essential for the diagnostic process.

Background: Functional connectivity density (FCD) could identify the abnormal intrinsic and spontaneous activity over the whole brain, and a seed-based resting-state functional connectivity (RSFC) could further reveal the altered functional network with the identified brain regions. This may be an effective assessment strategy for headache research. This study is to investigate the RSFC architecture changes of the brain in the patients with medication overuse headache (MOH) using FCD and RSFC methods., Methods: 3D structure images and resting-state functional MRI data were obtained from 37 MOH patients, 18 episodic migraine (EM) patients and 32 normal controls (NCs). FCD was calculated to detect the brain regions with abnormal functional activity over the whole brain, and the seed-based RSFC was performed to explore the functional network changes in MOH and EM., Results: The decreased FCD located in right parahippocampal gyrus, and the increased FCD located in left inferior parietal gyrus and right supramarginal gyrus in MOH compared with NC, and in right caudate and left insula in MOH compared with EM. RSFC revealed that decreased functional connectivity of the brain regions with decreased FCD anchored in the right dorsal-lateral prefrontal cortex, right frontopolar cortex in MOH, and in left temporopolar cortex and bilateral visual cortices in EM compared with NC, and in frontal-temporal-parietal pattern in MOH compared with EM., Conclusions: These results provided evidence that MOH and EM suffered from altered intrinsic functional connectivity architecture, and the current study presented a new perspective for understanding the neuromechanism of MOH and EM pathogenesis.

In Part 2 of Primary Headache disorders, we discuss the fourth Primary Headache Disorder, Tension-Type Headache (TTHA). We are again using the ICHD-III (Beta) definitions of such headaches, taking into consideration episodic and chronic TTHA, as well as the presence or absence of pericranial muscle tenderness. We discuss the pathophysiology and pharmacotherapeutic treatment of TTHA, and the aspects of the Myofascial Pain Syndrome that enhance and help the development of TTHA. We then discuss Medication Overuse Headache (MOH), itself a Secondary headache disorder, but one that is extremely important as it assists with the chronification of both migraine and TTHA. Finally we discuss how to manage and treat those patients with MOH. Chronic migraine, which is TTHA, Migraine as well as, in many patients, MOH, is discussed along with the treatment of this multifaceted disorder., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Little is known about the long-term course of headache in patients with moderate-to-severe headache due to traumatic brain injury (TBI). We evaluated the course of headache in patients with moderate-to-severe headache due to mild TBI., Methods: Since September 2009, patients with TBI prospectively rated their headache using a numeric rating scale (NRS). From the database containing 935 patients with TBI between September 2009 and December 2013, 259 patients were included according to following criteria: (1) newly onset moderate-to-severe headache (NRS ≥ 4) due to head trauma; (2) age ≥ 15 years; (3) Glasgow Coma Scale ≥ 13; (4) transient loss of consciousness ≤ 30 min; and (5) radiographic evaluation, such as computed tomography or magnetic resonance image. We evaluated initial and follow-up NRS scores to determine the significance of NRS changes and identified risk factors for moderate-to-severe headache at 36-month follow-up., Results: At 36-month follow-up, 225 patients (86.9%) reported improved headache (NRS ≤ 3) while 34 (13.1%) reported no improvement. The NRS scores were significantly decreased within a month (P < 0.001). The follow-up NRS scores at 12-, 24-, and 36-months were lower than those at one month (P < 0.001). Multiple logistic regression analysis showed that post-traumatic seizure (odds ratio, 2.162; 95% CI, 1.095-6.542; P = 0.041) and traumatic intracranial hemorrhage (odds ratio, 2.854; 95% CI, 1.241-10.372; P = 0.024) were independent risk factors for moderate-to-severe headache at 36-month follow-up., Conclusions: The course of headache in patients with mild TBI continuously improved until 36-month follow-up. However, 13.1% of patients still suffered from moderate-to-severe headache at 36-month follow-up, for whom post-traumatic seizure and traumatic intracranial hemorrhage might be risk factors.

Objective: To evaluate the intrinsic resting functional connectivity of the default mode network (DMN), salience network (SN), and central executive network (CEN) network in women with chronic migraine (CM), and whether clinical features are associated with such abnormalities., Methods: We analyzed resting-state connectivity in 29 women with CM as compared to age- and sex-matched controls. Relationships between clinical characteristics and changes in targeted networks connectivity were evaluated using a multivariate linear regression model., Results: All 3 major intrinsic brain networks were less coherent in CM (DMN: p = 0.030, SN: p = 0.007, CEN: p = 0.002) as compared to controls. When stratified based on medication overuse headache (MOH) status, CM without MOH (DMN: p = 0.029, SN: p = 0.023, CEN: p = 0.003) and CM with MOH (DMN: p = 0.016, SN: p = 0.016, CEN: p = 0.015) were also less coherent as compared to controls. There was no difference in CM with MOH as compared to CM without MOH (DMN: p = 0.382, SN: p = 0.408, CEN: p = 0.419). The frequency of moderate and severe headache days was associated with decreased connectivity in SN ( p = 0.003) and CEN ( p = 0.015), while cutaneous allodynia was associated with increased connectivity in SN ( p = 0.011)., Conclusions: Our results demonstrated decreased overall resting-state functional connectivity of the 3 major intrinsic brain networks in women with CM, and these patterns were associated with frequency of moderate to severe headache and cutaneous allodynia., (© 2017 American Academy of Neurology.)

In the last decade, a new surgical treatment modality was developed for frontal secondary headache, based on the assumption that the trigger of this pain entity is the entrapment of peripheral sensory nerves. The surgery entails a procedure, where an endoscopic approach is used to decompress the supraorbital and supratrochlear nerve branches, which are entrapped by the periosteum in the region of the corrugator supercilii muscle. Candidates for the surgery define their headache as moderate to severe persistent daily pressure or tension, localized in the frontal area, sometimes accompanied by symptoms of nausea and photophobia mimicking a primary headache-migraine. We created a step-by-step screening algorithm which is used to differentiate patients that have the highest chance for a successful surgical decompression. Up to now, published data regarding this type of surgery demonstrate long-lasting successful outcomes while adverse effects are minor. This article reviews and discusses from a surgeon's perspective decompression surgery for secondary headache attributed to supraorbital and supratrochlear nerve entrapment.

Background: Patients with medication-overuse headache suffer not only from chronic headache, but often from psychiatric comorbidities, such as anxiety and depression. The mechanisms underlying these comorbidities are unclear, but the amygdala is likely to be involved in their pathogenesis. To investigate the mechanisms underlying the comorbidities we used elevated plus maze and open field tests to assess anxiety-like behavior in rats chronically treated with analgesics. We measured the electrical properties of neurons in the amygdala, and examined the cortical spreading depression (CSD)-evoked expression of Fos in the trigeminal nucleus caudalis (TNC) and amygdala of rats chronically treated with analgesics. CSD, an analog of aura, evokes Fos expression in the TNC of rodents suggesting trigeminal nociception, considered to be a model of migraine., Results: Increased anxiety-like behavior was seen both in elevated plus maze and open field tests in a model of medication overuse produced in male rats by chronic treatment with aspirin or acetaminophen. The time spent in the open arms of the maze by aspirin- or acetaminophen-treated rats (53 ± 36.1 and 37 ± 29.5 s, respectively) was significantly shorter than that spent by saline-treated vehicle control rats (138 ± 22.6 s, P < 0.001). Chronic treatment with the analgesics increased the excitability of neurons in the central nucleus of the amygdala as indicated by their more negative threshold for action potential generation (-54.6 ± 5.01 mV for aspirin-treated, -55.2 ± 0.97 mV for acetaminophen-treated, and -31.50 ± 5.34 mV for saline-treated rats, P < 0.001). Chronic treatment with analgesics increased the CSD-evoked expression of Fos in the TNC and amygdala [18 ± 10.2 Fos-immunoreactive (IR) neurons per slide in the amygdala of rats treated with aspirin, 11 ± 5.4 IR neurons per slide in rats treated with acetaminophen, and 4 ± 3.7 IR neurons per slide in saline-treated control rats, P < 0.001]., Conclusions: Chronic treatment with analgesics can increase the excitability of neurons in the amygdala, which could underlie the anxiety seen in patients with medication-overuse headache.

Background: The marginal division of neostriatum (MrD) is a flat, pan-shaped zone between the neostriatum and the globus pallidus, and previous documents demonstrated that it was involved in the modulation of pain. The aim of this study is to investigate the roles of the MrD of the human brain in the chronicization migraine using resting state functional magnetic resonance imaging (rs-fMRI)., Methods: Conventional MRI, 3D structure images, and rs-fMRI were performed in 18 patients with episodic migraines (EM), 16 patients with chronic migraine (CM), 44 patients with medication overuse headache plus chronic migraine (MOH + CM), and 32 normal controls (NC). MrD was defined using manual delineation on structural images, and was selected as the seed to calculate the functional connectivity (FC)., Results: Compared with the NC group, the decreased FC of MrD was observed in the EM and CM groups, and increased FC of MrD was demonstrated in all patient groups. Compared with the EM group, the decreased FC of MrD was revealed in the CM and MOH + CM groups, and the increased FC occurred only in the CM group. Increased FC of MrD alone was observed in the MOH + CM group compared with that in the CM group., Conclusion: This study confirmed the double neuromodulation network of MrD in pain modulation and migraine chronicization; however, the mechanism requires further investigation.

A 73-year-old man presented with a 6-month history of exertional headaches. Exercise tolerance test demonstrated progressive ischaemic changes concomitant with worsening headache. Cardiac cephalgia was diagnosed and his symptoms resolved after coronary artery bypass surgery. Cardiac cephalgia may occasionally present as exertional headache without chest symptoms., (© 2016 Royal Australasian College of Physicians.)

Medication-overuse headache (MOH) is defined by the International Classification of Headache Disorders as a headache in patients with a pre-existing primary headache disorder that occurs on ≥15 days per month for >3 months, and is caused by overuse of medication intended for acute or symptomatic headache treatment. The prevalence of MOH in the general population is around 1%, but the condition is much more common in people with headache, in particular chronic migraine. The phenotype of the headache in MOH depends on the initial primary headache and the type of overused acute medication. In this Review, we will discuss the epidemiology, risk factors, pathophysiology, prevention and treatment of MOH. Treatment of MOH is performed in three steps: educating patients about the relationship between frequent intake of acute headache medication and MOH with the aim to reduce intake of acute medication; initiation of migraine prevention (such as topiramate or onabotulinumtoxin A in migraine) in patients who fail step 1; detoxification on an outpatient basis or in a day hospital or inpatient setting, depending on severity and comorbidities. The success rate of treatment is around 50-70%, although patients whose MOH is associated with opioid overuse have higher relapse rates. In all patients with MOH, relapse rates can be reduced by patient education and care in the follow-up period.

Primary and secondary headache disorders have established diagnostic criteria in the International Classification of Headache Disorders IIIb, as well as classic findings, which although not part of the formal criteria are often suggestive of a particular diagnosis. At times, headache disorders can involve unusual symptoms that lack an identifiable secondary cause. This review will discuss some of these unusual symptoms, including headache associated auditory and olfactory symptoms, as well as two case reports involving gelastic migraine and migrainous thoracalgia.

Children and adolescents with sickle cell disease (SCD) have a high prevalence of recurrent headaches (24.0-43.9 %). Acute presentation with headache can be diagnostically challenging, as the clinician must consider evaluation of several potentially devastating conditions including vascular diseases (stroke, hemorrhage, venous sinus thrombosis, moyamoya, posterior reversible encephalopathy syndrome), facial and orbital bone infarcts, dental pain, and osteomyelitis. Patients with SCD and primary headache disorders may benefit from comprehensive headache treatment plans that include abortive therapy, prophylactic therapy, and non-pharmacological modalities. Although there is limited data in adults, those with SCD are at risk for medication overuse headache secondary to frequent opioid use. Addressing headache in patients with SCD may help to reduce their use of opioids and disability and improve pain and quality of life.

Objective: The aim of this study was to estimate the prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients with primary headaches attended in a tertiary neurology ambulatory., Method: Authorized by the Ethics Committee, the present cross-sectional study was conducted with a random sample of patients screened for orofacial pain and primary headaches at a tertiary hospital in Northeast of Brazil., Results: The sample consisted in 42 patients with primary headache, 59.5% male. The prevalence of > 6 TMD signs and symptoms was 54.8%. In those patients with migraine TMD was present in 71.4% and in tension-type headache in 38.1% (p = 0.030; OR = 4.1). TMD was related to the clinical status of headache associated or attributed to medication overuse (p = 0.001)., Conclusion: TMD has a high prevalence in patients with primary headaches (54.8%). Special attention must be given to patients with migraine and headache associated or attributed to medication overuse.

Headaches from vascular causes need to be differentiated from primary headaches because a misdiagnosis may lead to dire consequences for the patient. Neuroimaging is critical in identifying patients with vascular headaches and identifying the nature of the pathologic disorder causing these headaches. In addition, the imaging findings guide the physician regarding the optimal treatment modality for these lesions. This review summarizes the nuances of differentiating patients with secondary headaches related to vascular disease and discusses pertinent neuroimaging studies.

"Cardiac cephalgia" is a type of secondary headache disorder, usually initiated by exertion that is related to myocardial ischemia. Primary exertional headaches such as sex-, cough-, or exercise-induced headaches are typically benign. Cardiac cephalgia, on the other hand, can have life-threatening complications. Due to overlapping features and similarities in presentation, cardiac cephalgia can be misdiagnosed as a primary headache disorder such as migraine. However, the management of these conditions is unique, and treatment of cardiac cephalgia with vasoconstrictors intended for migraine can potentially worsen myocardial ischemia. Thus, it is important to make the correct diagnosis by evaluating cardiac function with an electrocardiogram and/or stress testing. In this review, we examine reported cases of cardiac cephalgia from the past 5 years to highlight the importance of this condition in the differential diagnosis of a headache in a patient with a history of cardiovascular risk factors, as well as to discuss the appropriate approach to diagnosis and the proposed pathogenic mechanisms of this condition.

Pediatric and adolescence headache is one of the most common causes of access in emergency departments (ED). Primary headache and headache secondary to self-limited conditions are the majority of cases. Secondary life-threatening headaches are less frequent and may be recognized by a careful history and physical examination. The primary objective for ED physicians is to recognize the serious life-threatening conditions requiring immediate medical care among the wide spectrum of headache diagnoses.

Medication overuse headache (MOH) is a common and disabling headache disorder. It has a prevalence of about 1-2 % in the general population. The International Classification of Headache Disorders 3rd edition (beta version) has defined MOH as a chronic headache disorder in which the headache occurs on 15 or more days per month due to regular overuse of medication. These headaches must have been present for more than 3 months. The pathophysiology is complex and not completely known. It involves genetic and behavioural factors. There is evidence that cortical spreading depression, trigeminovascular system and neurotransmitters contribute to the pain pathway of MOH. The treatment of MOH includes patient education, stopping the offending drug(s), rescue therapy for withdrawal symptoms and preventative therapy. Relapse rates for MOH are high at 41 %. MOH can severely impact quality of life, so it is important to identify patients who are at risk of analgesic overuse.

Sports- and exercise-related headaches are not unusual. Despite their frequent occurrence in this context, there are little epidemiologic data concerning sports-related headache. The recent attention of concussive injuries and associated post-traumatic headache has renewed interest in the study of those headaches occurring after head trauma; however, any primary headache type can also occur in the setting of contact and/or collision sports. The nonspecific nature of headaches provides unique challenges to clinicians encountering this complaint. It is, therefore, imperative that physicians treating athletes are able to distinguish the various headache types and presentations often seen in this population.

Background: Several imaging studies have identified localized anatomical and functional brain changes in medication-overuse headache (MOH)., Objective: The objective of this article is to evaluate whole-brain functional connectivity at rest together with voxel-based morphometry in MOH patients, in comparison with episodic migraine (EM) patients and healthy controls (HCs)., Methods: Anatomical MRI and resting-state functional MRI scans were obtained in MOH patients (n = 17 and 9, respectively), EM patients (n = 18 and 15, respectively) and HCs (n = 17 and 17). SPM8 was used to analyze voxel-based morphometry and seed (left precuneus) to voxel connectivity data in the whole brain., Results: Functional connectivity at rest was altered in MOH patients. Connectivity was decreased between precuneus and regions of the default-mode network (frontal and parietal cortices), but increased between precuneus and hippocampal/temporal areas. These functional modifications were not accompanied by significant gross morphological changes. Furthermore, connectivity between precuneus and frontal areas in MOH was negatively correlated with migraine duration and positively correlated with self-evaluation of medication dependence. Gray matter volumes of frontal regions, precuneus and hippocampus were also negatively related to migraine duration. Functional connectivity within the default-mode network appeared to predict anxiety scores of MOH patients while gray matter volumes in this network predicted their depression scores., Conclusions: Our data suggest that MOH is associated with functional alterations within intrinsic brain networks rather than with macrostructural changes. They also support the view that dependence-related processes might play a prominent role in its development and maintenance., (© International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Objective: The objective of this article is to evaluate electrically evoked thresholds for cortical spreading depression (CSD) and stress-induced activation of trigeminal afferents in a rat model of medication-overuse headache (MOH)., Methods: Sumatriptan or saline was delivered subcutaneously by osmotic minipump for six days to Sprague-Dawley rats. Two weeks after pump removal, animals were anesthetized and recording/stimulating electrodes implanted. The animals were pretreated with vehicle or topiramate followed by graded electrical stimulation within the visual cortex. CSD events were identified by decreased EEG amplitude and DC potential shift. Additional unanesthetized sumatriptan or saline-pretreated rats were exposed to bright light environmental stress and periorbital and hindpaw withdrawal thresholds were measured. Following CSD stimulation or environmental stress, immunohistochemical staining for Fos in the trigeminal nucleus caudalis (TNC) was performed., Results: Sumatriptan pre-exposure significantly decreased electrical stimulation threshold to generate a CSD event. Topiramate normalized the decreased CSD threshold as well as stress-induced behavioral withdrawal thresholds in sumatriptan-treated rats compared to saline-treated animals. Moreover, CSD and environmental stress increased Fos expression in the TNC of sumatriptan-treated rats, and these effects were blocked by topiramate. Environmental stress did not elicit cutaneous allodynia or elevate TNC Fos expression in saline-treated rats., Conclusions: A previous period of sumatriptan exposure produced long-lasting increased susceptibility to evoked CSD and environmental stress-induced activation of the TNC that was prevented by topiramate. Lowered CSD threshold, and enhanced consequences of CSD events (increased activation of TNC), may represent an underlying biological mechanism of MOH related to triptans., (© International Headache Society 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Intractable chronic headaches are a major challenge for both patients and healthcare professionals. Over the last two decades, implantable electrical neuromodulators, previously established to manage other forms of chronic pain, have been used increasingly for intractable primary and secondary headache disorders. We review the current approaches to the management of refractory headaches using neuromodulation. Indications, operative considerations and complications are discussed based on our experience and a review of the literature. The field of neuromodulation has been rapidly advancing, with many new targets being discovered and novel devices being developed for treating craniofacial pain. We discuss some of these targets, detailing the latest advances in the area of neuromodulation for intractable headaches.