Sumatriptan in migraine with unilateral cranial autonomic symptoms: an open study

Pathophysiology of cluster headache: From the trigeminovascular system to the cerebral networks

BACKGROUND

Despite advances in neuroimaging and electrophysiology, cluster headache's pathogenesis remains unclear. This review will examine clinical neurophysiology studies, including electrophysiological and functional neuroimaging, to determine if they might help us construct a neurophysiological model of cluster headache.

RESULTS

Clinical, biochemical, and electrophysiological research have implicated the trigeminal-parasympathetic system in cluster headache pain generation, although the order in which these two systems are activated, which may be somewhat independent, is unknown. Electrophysiology and neuroimaging have found one or more central factors that may cause seasonal and circadian attacks. The well-known posterior hypothalamus, with its primary circadian pacemaker suprachiasmatic nucleus, the brainstem monoaminergic systems, the midbrain, with an emphasis on the dopaminergic system, especially when cluster headache is chronic, and the descending pain control systems appear to be involved. Functional connection investigations have verified electrophysiological evidence of functional changes in distant brain regions connecting to wide cerebral networks other than pain.

CONCLUSION

We propose that under the impact of external time, an inherited misalignment between the primary circadian pacemaker suprachiasmatic nucleus and other secondary extra- suprachiasmatic nucleus clocks may promote disturbance of the body's internal physiological clock, lowering the threshold for bout recurrence.

Predictors of response to anti-CGRP monoclonal antibodies: a 24-week, multicenter, prospective study on 864 migraine patients

Background and objectives

The identification of predictors of response to antiCGRP mAbs could favor tailored therapies and personalized treatment plans. This study is aimed at investigating predictors of ≥ 50%, ≥ 75% and 100% response at 24 weeks in patients with high-frequency episodic (HFEM: 8–14 days/month) or chronic migraine (CM).

Methods

This is a large, multicenter, cohort, real-life study. We considered all consecutive adult patients affected by HFEM or CM who were prescribed antiCGRP mAbs for ≥ 24 weeks in 20 headache centers. Patients were interviewed face-to-face using a shared semi-structured questionnaire carefully exploring socio-demographic and clinical characteristics. Patients received subcutaneous erenumab (70 mg or140 mg, monthly), galcanezumab (120 mg monthly, following a 240 mg loading dose), or fremanezumab (225 mg, monthly or 675 mg, quarterly) according to drug market availability, physician’s choice, or patient’s preference. The primary endpoint of the study was the assessment of ≥ 50% response predictors at 24 weeks. Secondary endpoints included ≥ 75% and 100% response predictors at 24 weeks.

Results

Eight hundred sixty-four migraine patients had been treated with antiCGRP mAbs for ≥ 24 weeks (erenumab: 639 pts; galcanezumab: 173 pts; fremanezumab: 55 pts). The ≥50% response (primary endpoint) in HFEM was positively associated with unilateral pain (UP) + unilateral cranial autonomic symptoms (UAs) (OR:4.23, 95%CI:1.57–11.4; p = 0.004), while in CM was positively associated with UAs (OR:1.49, 95%CI:1.05–2.11; p = 0.026), UP + UAs (OR:1.90, 95%CI:1.15–3.16; p = 0.012), UP + allodynia (OR:1.71, 95%CI:1.04–2.83; p = 0.034), and negatively associated with obesity (OR:0.21, 95%CI:0.07–0.64; p = 0.006). The 75% response (secondary endpoint) was positively associated with UP + UAs in HFEM (OR:3.44, 95%CI:1.42–8.31; p = 0.006) and with UP + UAs (OR:1.78, 95%CI:1.14–2.80; p = 0.012) and UP + allodynia (OR:1.92, 95%CI:1.22–3.06; p = 0.005) in CM. No predictor of 100% response emerged in patients with HFEM or CM.

Conclusions

A critical evaluation of headache characteristics indicating peripheral or central sensitization may help in predicting responsiveness to antiCGRP mAbs in HFEM and CM. A more precise pain profiling may represent a steppingstone for a mechanism-based approach and personalized treatment of migraine with compounds targeting specific molecular mechanisms.

Cranial autonomic symptoms and response to monoclonal antibodies targeting the Calcitonin gene-related peptide pathway: A real-world study

Objective

Cranial autonomic symptoms (CAS), including conjunctival injection, tearing, nasal congestion or rhinorrhea, eyelid edema, miosis or ptosis, and forehead or facial sweating ipsilateral to headache, are often reported by patients with migraine during headache attacks. CAS is a consequence of the activation of the trigeminovascular system, which is the target of monoclonal antibodies acting on the CGRP pathway. Therefore, we hypothesized that patients with CAS might have higher trigeminovascular activation than those without CAS leading to a better response to anti-CGRP treatments.

Methods

We performed a prospective analysis including patients with episodic or chronic migraine treated with anti-CGRP monoclonal antibodies (i.e., erenumab, fremanezumab, and galcanezumab) between 2019 and 2021. The observation period included a 12-week baseline before treatment with anti-CGRP antibodies and a 12-week treatment follow-up. We evaluated the prevalence of CAS in our cohort and compared disease characteristics and treatment response (i.e., 12-week monthly headache days and 0–29, 30–49, 50–74, 75–99, and 100% monthly headache days reduction from baseline) among patients with and without CAS using the χ² test, Kruskal–Wallis test, and Mann–Whitney U-test.

Results

Out of 136 patients, 88 (65%) had CAS. Both patients with and without CAS reported a significant decrease in monthly headache days from baseline. During the 12-week follow-up, the median difference in monthly headache days from baseline was higher in patients with CAS (-10, IQR−15 to−6) than in those without CAS (6, IQR 12 to 3; P = 0.009). However, the proportions of patients with 0 to 29, 30 to 49, 50 to 74, 75 to 99, and 100% response rates did not differ between the two groups.

Conclusions

In our cohort, the presence of CAS was associated with a greater response to monoclonal antibodies targeting the CGRP pathway. CAS could be a clinical marker of trigeminovascular activation and thus be related to a better response to CGRP treatments.

Rapid response to galcanezumab and predictive factors in chronic migraine patients: A 3-month observational, longitudinal, cohort, multicenter, Italian real-life study

BACKGROUND AND PURPOSE

A rapid response to preventive therapy is of pivotal importance in severely disabled patients with chronic migraine (CM) and diverse preventive treatment failures. This prospective, observational, multicenter real-life study aimed at investigating the effectiveness of galcanezumab in the first 3 months of treatment of CM patients at 14 Italian headache centers.

METHODS

All consecutive adult patients with CM diagnosis with the clinical indication for galcanezumab were considered. We collected patients' baseline characteristics, monthly headache days, monthly painkiller intake, migraine clinical characteristics, and disability scale scores during a 1-month run-in period (baseline) and the first 3 months of therapy. Possible predictive factors of treatment were considered.

RESULTS

A total of 156 patients (82.4% female, aged 47.3 ± 12.3 years) were enrolled. The 65 (41.7%) patients with a consecutive ≥50% response rate (RR) in the 3 months of therapy presented a lower body mass index (p = 0.004) and more frequently presented unilateral migraine pain (p = 0.002) and good response to triptans (p = 0.003). Persistent conversion from CM to episodic migraine was observed in 55.8% (87/156) of patients. They more frequently presented a good response to triptans (p = 0.003) and unilateral pain (p = 0.046). At baseline, 131 of 156 (83.9%) patients presented medication overuse (MO). Of these, 61.8% (81/131) no longer displayed MO consistently during the 3 months. These patients were more frequently responders to triptans (p = 0.002) and less frequently suffered from gastrointestinal comorbidity (p = 0.007).

CONCLUSIONS

Unilateral pain, good response to triptans, and normal weight may be associated with a persistent positive response in the first 3 months of therapy with galcanezumab in CM patients.

Cranial autonomic symptoms in migraine are related to central sensitization: a prospective study of 164 migraine patients at a tertiary headache center

Background

Cranial autonomic symptoms (CASs) during migraine attacks are reported to be quite common regardless of ethnicity. In our previous study investigating 373 migraineurs, we found that 42.4% of them had CASs. The patients with CASs more frequently had cutaneous allodynia than did those without CASs, and we speculated that CASs were associated with central sensitization. The present study searched for substantial evidence on the relationship between CASs and central sensitization in migraine patients.

Methods

This was a prospective cross-sectional study. We studied a new independent cohort of 164 migraineurs who presented to the Tominaga Hospital Headache Center from July 2018 until December 2019. The clinical features of CASs according to the criteria in ICHD-3 (beta) were investigated. We also evaluated central sensitization based on the 25 health-related symptoms utilizing the validated central sensitization inventory (CSI), and each symptom was rated from 0 to 4 resulting a total score of 0–100.

Results

The mean age was 41.8 (range: 20 to 77) years old. One hundred and thirty-one patients (78.9%) were women. Eighty-six of the 164 (52.4%) patients had at least 1 cranial autonomic symptom. The CSI score of the patients with ≥3 CASs reflected a moderate severity and was significantly higher than in those without CASs (41.9 vs. 30.7, p = 0.0005). The score of the patients with ≥1 conspicuous CAS also reflected a moderate severity and was significantly higher than in those without CASs (40.7 vs. 33.2, p = 0.013). The patients in the CSI ≥40 group had lacrimation, aural fullness, nasal blockage, and rhinorrhea, which are cranial autonomic parasympathetic symptoms, significantly more frequently than those in the CSI < 40 group.

Conclusions

Migraine patients with CASs showed significantly greater central sensitization than those without such symptoms. In particular, cranial parasympathetic symptoms were more frequent in centrally sensitized patients than in nonsensitized patients, suggesting that cranial parasympathetic activation may contribute to the maintenance of central sensitization.

Trial registration

This study was retrospectively registered with UMIN-CTR on 29 Aug 2020 (UMIN000041603).

Cranial autonomic symptoms: prevalence, phenotype and laterality in migraine and two potentially new symptoms

Background

Whilst cranial autonomic symptoms (CAS) are typically associated with trigeminal autonomic cephalalgias (TAC’s), they have also been reported in migraine. Identification and understanding of these symptoms in migraine is important to ensure timely diagnosis and effective management.

Methods

Migraineurs seen in a tertiary headache service between 2014 and 2018 (n = 340): cohort one, and a separate cohort of headache patients seen between 2014-May 2021 reporting voice change, or throat swelling, or both, as CAS were selected (n = 64): cohort two. We performed a service evaluation of our records regarding age, sex, diagnosis, headache and CAS frequency and laterality as acquired from the first consultation, during which a detailed headache history is taken by a headache trained physician.

Results

Cohort 1: Mean age 43 (range 14–94, SD 15). The most common diagnosis was chronic migraine (78%). Median monthly headache frequency was 26 days (IQR 15–75). At least one CAS was reported in 74%, with a median of two (IQR 0–3). The most common were nasal congestion (32%), lacrimation (31%) and aural fullness (25%). Most patients reported their most common headache as unilateral (80%) and with it strictly unilateral CAS (64%). There was a positive association between headache and CAS laterality (χ²₁ = 20.7, P < 0.001), with a positive correlation between baseline headache frequency and number of CAS reported (r = 0.11, P = 0.047). Cohort two: mean age 49 (range 23–83, SD 14). Diagnoses were chronic migraine (50%), chronic cluster headache (11%), undifferentiated continuous lateralised headache (9%), SUNCT/SUNA (8%), hemicrania continua (8%), episodic migraine (8%), episodic cluster headache (3%) and trigeminal neuropathies (3%). Most (89%) described trigeminal distribution pain; 25% involving all three divisions. Throat swelling was reported by 54, voice change by 17, and both by 7. The most common CAS reported were lacrimation (n = 47), facial swelling (n = 45) and rhinorrhoea (n = 37). There was significant agreement between the co-reporting of throat swelling (χ²₁ = 7.59, P = 0.013) and voice change (χ²₁ = 6.49, P = 0.02) with aural fullness.

Conclusions

CAS are common in migraine, are associated with increasing headache frequency and tend to lateralise with headache. Voice change and throat swelling should be recognized as possible parasympathetically-mediated CAS. They may be co-associated and associated with aural fullness, suggesting a broadly somatotopic endophenotype.

Cranial autonomic symptoms in episodic and chronic migraine: a cross sectional study in Iran

BACKGROUND

Cranial autonomic symptoms are common in migraine, with eye redness and tearing being the most common ones. Their identification can help to avoid misdiagnosis, predict the disease course, and select the appropriate treatment.

METHODS

This was a cross-sectional study of 904 patients who presented with migraine to a headache referral clinic. The participants filled out a questionnaire about their headache characteristics, as well as the presence of cranial autonomic symptoms. A total of 904 patients, 698 women (77.2%) and 206 men (22.8%), were included in the study, with a mean (SD) age of 38.05 (11.76) years.

RESULTS

About 70% of subjects with chronic migraine and 56.2% of those with episodic migraine reported one or more cranial autonomic symptoms. The two most commonly reported autonomic symptoms were eye redness (36.06%) and tearing (21.02%). Chronic migraine (43.4% vs. 29.5%), unilateral headache (56.8% vs. 48.7%), and blurred vision (20% vs. 14.7%) were significantly more frequent in migraineurs with cranial autonomic symptoms. Headache intensity and frequency in subjects with cranial autonomic symptoms were significantly higher than in those without cranial autonomic symptoms.

CONCLUSION

We found higher percentages of cranial autonomic symptoms in patients with unilateral headaches, frequent and severe attacks and blurred vision. A diagnosis of cranial autonomic symptoms accompanying migraine may predict more severe disease and the possibility of evolution into chronic migraine.

Clinical features, disease progression, and use of healthcare resources in a large sample of 866 patients from 24 headache centers: A real-life perspective from the Italian chROnic migraiNe (IRON) project

OBJECTIVE

To develop a dedicated Italian chronic migraine (CM) database (IRON project) to overcome disease misconceptions, improve clinical administration, reduce patients' burden, and rationalize economic resource allotment.

BACKGROUND

Proper CM management requires a comprehensive appraisal of its full clinical, social, and economic complexity.

METHODS

In this cross-sectional study, CM patients were screened in 24 certified headache centers with face-to-face interviews. Information on sociodemographic factors, medical history, characteristics of CM, and of prior episodic migraine (EM), and healthcare resource use was gathered using a semistructured web-based questionnaire.

RESULTS

A total of 866 CM patients were enrolled. CM started ~20 years after EM onset (age at EM onset 17.4 ± 9.1 vs. age at CM onset 35.3 ± 12.5 [mean ± SD]). CM prophylaxis, used by 430/866 (49.6%) of the patients, was often ineffective, not tolerated, and prematurely discontinued. Medications and diagnostic workup, frequently inappropriate, were mostly subsidized by the Italian national health service. CM patients with ≥25 headache days/month revealed substantial clinical differences and heavier disability and economic burden compared with those with <25 headache days/month.

CONCLUSIONS

CM is a heterogeneous headache disorder deserving more in-depth clinical characterization, sharper diagnostic criteria, and tailored treatments. CM registries are expected to improve clinical management, resulting in increased disease awareness, better healthcare resource allocation, and reduced economic burden.

Craniofacial Autonomic Dysfunction in Migraine: Implications for Treatment and Prognosis

BACKGROUND

Craniofacial autonomic signs and symptoms (CASS) are relatively underrecognized in the evaluation of migraine headache. Yet, these features provide insight into diagnostic criterion, therapeutic approaches, and overarching disease burden.

EVIDENCE ACQUISITION

This review aims to summarize relevant literature evaluating autonomic dysfunction, with focus on CASS, in migraine through targeted literature searches in PubMed. Full articles of original data published between 1974 and 2019 were identified using MeSH terms with no search limits.

RESULTS

Although CASS are typically clinically evaluated by subjective patient report, investigational measures of cranial autonomic function have identified marked distinctions between headache attack and attack-free intervals. The presence of CASS during an attack does not differ based on age, sex, or presence of aura. Unilateral CASS may be predictive of longer, more frequent, and/or severe attacks and often co-occur with sensory dysfunction such as allodynia and photophobia. Although limited research has been performed to evaluate targeted therapeutics for migraine with CASS, triptans and onabotulinumtoxinA may demonstrate greater effects in this group.

CONCLUSIONS

Migraine remains a debilitating disorder with significant community-wide impacts, necessitating continued evaluation of contributing features. Consideration of CASS provides important insight into potential treatment approaches and the effectiveness of novel therapeutic interventions aimed at improving overall disease burden. However, further investigation is needed to fully understand primary craniofacial features in migraine, and how these might inform individualized treatment decisions.

Erenumab in the prevention of high-frequency episodic and chronic migraine: Erenumab in Real Life in Italy (EARLY), the first Italian multicenter, prospective real-life study

OBJECTIVE

To assess the effectiveness, safety, and tolerability of erenumab in a real-life migraine population, while trying to identify responsiveness predictors.

BACKGROUND

Erenumab is a fully human Ig-2 monoclonal antibody blocking the calcitonin gene-related peptide receptor, indicated for migraine prophylaxis. Phase II and III trials demonstrated that erenumab is effective, safe, and well tolerated in the prevention of episodic and chronic migraine (CM), showing an early onset of action.

METHODS

This is a multicenter, prospective, cohort, and real-life study. We considered for enrolment all consecutive patients aged 18-65 affected by high-frequency episodic migraine (HFEM) or CM, with or without medication overuse, visited at nine Italian Headache Centers from December 20, 2018 to September 30, 2019. Each patient was treated with erenumab 70 mg, administered subcutaneously every 4 weeks. Treatment duration was planned to last from 6 to 12 months, depending on the patient's response. The primary endpoint was the change in monthly migraine days (MMDs) at weeks 9-12 compared to baseline. Secondary endpoints included changes in monthly analgesics intake, ≥50%, ≥75%, and 100% responder rates and any variation in the Visual Analog Scale (VAS) and Headache Impact Test scores (HIT).

RESULTS

In total, 372 migraine patients were treated with at least one dose of erenumab 70 mg. At weeks 9-12, erenumab decreased MMDs by 4.5 ± 4.1 days (mean ± SD) in patients with HFEM and by 9.3 ± 9.1 (mean ± SD) days in those with CM compared to baseline. At weeks 9-12 VAS score was reduced by 1.9 ± 1.9 (mean ± SD), HIT score by 10.7 ± 8.8 (mean ± SD), and median monthly analgesics intake passed from 12.0 (interquartile range [IQR] 10.0-14.0) to 5.0 (IQR 3.0-7.0) in HFEM. In CM patients, VAS was reduced by 1.7 ± 2.0 (mean ± SD), HIT by 9.7 ± 10.4 (mean ± SD), and median monthly analgesics intake passed from 20.0 (IQR 15.0-30.0) to 8.0 (IQR 5.0-15.0). At week 12, ≥50% responders were 60/101 (59.4%) for HFEM and 146/263 (55.5%) for CM, ≥75% responders were 17/101 (16.8%) and 59/263 (22.4%) and 100% responders 1/101 (1.0%) and 3/263 (1.1%), respectively. Erenumab responsiveness in HFEM was positively associated with unilateral pain localization (OR: 3.03, 95% CI: 1.24-7.40; p = 0.015), whereas in CM responsiveness was positively associated with and baseline migraine frequency (OR: 1.06, 95% CI:1.02-1.11; p = 0.031), dopaminergic symptoms (OR: 2.01, 95% CI: 1.14-3.52; p = 0.015), and negatively associated with psychiatric comorbidities (OR: 0.43, 95% CI: 0.20-0.93; p = 0.003).

CONCLUSIONS

Erenumab 70 mg is effective, safe, and well tolerated in real life. Easily obtainable clinical features might be of help in predicting patient's responsiveness.

Predicting the response to a triptan in migraine using deep attack phenotyping: A feasibility study

Background

Triptans, specific symptomatic medications for migraine, are not effective in a proportion of patients, or in all attacks, hence the importance of identifying predictors of response. Our aim was to investigate the association between the efficacy of oral frovatriptan 2.5 mg and clinical characteristics of migraine attacks.

Methods

We enrolled 29 consecutive patients affected by migraine without aura at the Headache Center of “Mondino” Institute of Pavia. Each patient was given a diary and asked to record prospectively the features of three consecutive migraine attacks while using frovatriptan. A generalized estimating equations approach was used to determine phenotypic features associated with the pain free response at 2 hours.

Results

Participants provided complete data for 85 attacks. Thirty of these (34%) patients reported being pain free 2 hours after taking frovatriptan 2.5 mg intake. Unilateral pain, presence of phonophobia, presence of one or more cranial autonomic symptoms and presence of one or more premonitory symptom were each associated with being pain free at 2 hours.

Conclusions

The response to frovatriptan was associated with particular features of the migraine attack, either before or during the pain phase of attacks. The data support larger studies to explore detailed attack phenotyping, with particular attention to early signs, to enable individualized treatment in migraine.

Circulating Biomarkers in Migraine: New Opportunities for Precision Medicine

Background:

Migraine is the most common neurological disorder and the second most disabling human condition, whose pathogenesis is favored by a combination of genetic, epigenetic, and environmental factors. In recent years, several efforts have been made to identify reliable biomarker(s) useful to monitor disease activity and/or ascertain the response to a specific treatment.

Objective:

To review the current evidence on the potential biological markers associated with migraine.

Methods:

A structured search of peer-reviewed research literature was performed by searching major publications databases up to December 2017.

Results:

Several circulating biomarkers have been proposed as diagnostic or therapeutic tools in migraine, mostly related to migraine’s inflammatory pathophysiological aspects. Nonetheless, their detection is still a challenge for the scientific community, reflecting, at least in part, disease complexity and clinical diagnostic limitations. At the present time, calcitonin generelated peptide (CGRP) represents probably the most promising candidate as a diagnostic and/or therapeutic biomarker, as its plasma levels are elevated during migraine attack and decrease during successful treatment. Other molecules (including some neuropeptides, cytokines, adipokines, or vascular activation markers) despite promising, do not possess the sufficient prerequisites to be considered as migraine biomarkers.

Conclusion:

The characterization of migraine-specific biomarkers would be fundamental in a perspective of precision medicine, enabling risk assessment and tailored treatments. However, speculating on the clinical validity of migraine biomarkers may be premature and controlled clinical trials are presently needed to investigate both the diagnostic and therapeutic value of these biomarkers in migraine.

Pupil Cycle Time Distinguishes Migraineurs From Subjects Without Headache

Migraine is a neurological disorder characterized by paroxysms of head pain accompanied by trigeminovascular system activation and autonomic dysfunction. Diagnosis is currently based on clinical diagnostic criteria. Though physiological differences exist between migraineurs and non-headache controls, true physiological biomarkers have been elusive, especially for the full clinical spectrum of migraine, inclusive of chronic, episodic, and probable migraine. We used edge-light pupil cycle time (PCT) as a probe of the pupillary light circuit in migraine, paired with clinical assessment of migraine characteristics, and compared these to non-headache controls. We found significantly increased PCT in probable, episodic, and chronic migraine, compared to controls. Additionally, increased PCT correlated with the presence of craniofacial autonomic symptoms, linking pupillary circuit dysfunction to peripheral trigeminal sensitization. The sensitivity of PCT, especially for all severities of disease, distinguishes it from other physiological phenotypes, which may make it useful as a potential biomarker.

Recent Advances in Pharmacotherapy for Migraine Prevention: From Pathophysiology to New Drugs

Migraine is a common and disabling neurological disorder, with a significant socioeconomic burden. Its pathophysiology involves abnormalities in complex neuronal networks, interacting at different levels of the central and peripheral nervous system, resulting in the constellation of symptoms characteristic of a migraine attack. Management of migraine is individualised and often necessitates the commencement of preventive medication. Recent advancements in the understanding of the neurobiology of migraine have begun to account for some parts of the symptomatology, which has led to the development of novel target-based therapies that may revolutionise how migraine is treated in the future. This review will explore recent advances in the understanding of migraine pathophysiology, and pharmacotherapeutic developments for migraine prevention, with particular emphasis on novel treatments targeted at the calcitonin gene-related peptide (CGRP) pathway.

Redox Mechanisms in Migraine: Novel Therapeutics and Dietary Interventions

SIGNIFICANCE

Migraine represents the third most prevalent and the seventh most disabling human disorder. Approximately 30% of migraine patients experience transient, fully reversible, focal neurological symptoms (aura) preceding the attack. Recent Advances: Awareness of the hypothesis that migraine actually embodies a spectrum of illnesses-ranging from episodic to chronic forms-is progressively increasing and poses novel challenges for clarifying the underlying pathophysiological mechanisms of migraine as well as for the development of novel therapeutic interventions. Several theories have evolved to the current concept that a combination of genetic, epigenetic, and environmental factors may play a role in migraine pathogenesis, although their relative importance is still being debated.

CRITICAL ISSUES

One critical issue that deserves a particular attention is the role of oxidative stress in migraine. Indeed, potentially harmful oxidative events occur during the migraine attack and long-lasting or frequent migraine episodes may increase brain exposure to oxidative events that can lead to chronic transformation. Moreover, a wide variety of dietary, environmental, physiological, behavioral, and pharmacological migraine triggers may act through oxidative stress, with clear implications for migraine treatment and prophylaxis. Interestingly, almost all current prophylactic migraine agents exert antioxidant effects.

FUTURE DIRECTIONS

Increasing awareness of the role of oxidative stress and/or decreased antioxidant defenses in migraine pathogenesis and progression to a chronic condition lays the foundations for the design of novel prophylactic approaches, which, by reducing brain oxidative phenomena, could favorably modify the clinical course of migraine. Antioxid. Redox Signal. 28, 1144-1183.

Onabotulinum toxin A in the treatment of chronic migraine: patient selection and special considerations

Discovered by serendipity, onabotulinum toxin A (BoNT-A) is the only US Food and Drug Administration-approved treatment for the prevention of chronic migraine (CM), one of the most disabling and burdensome human conditions. Its efficacy, safety and tolerability, proved by the largest and longest migraine therapeutic trial (the Phase III Research Evaluating Migraine Prophylaxis Therapy program [PREEMPT]), have been replicated by various real-life studies also in the presence of medication overuse. The benefit of BoNT-A prophylaxis is likely due to its ability to counteract peripheral and central nociceptive sensitization through reversible chemical denervation of pericranial sensitive afferents. Its efficacy increases considerably over time during long-term treatments, significantly varying among patients. The present review focuses on the state-of-the art of current knowledge on putative instrumental, biochemical and clinical predictors of BoNT-A responsiveness, outlining the need for a thorough characterization of the full phenotypic migraine picture when trying to predict good responders. Available evidence suggests that disentangling the BoNT-A responsiveness puzzle requires 1) a reappraisal of easy-obtainable clinical details (eg, site and quality of pain, presence of cranial autonomic symptoms), 2) a proper stratification of patients with CM according to their headache frequency, 3) the evaluation of potential synergistic effects of concomitant prophylaxis/treatment and 4) a detailed assessment of modifiable risk factors evolution during treatment.

Clinical-Biochemical Correlates of Migraine Attacks in Rizatriptan Responders and Non-Responders

The present study was aimed at verifying the clinical characteristics of a typical attack in 20 migraine patients, 10 responders and 10 non-responders to rizatriptan, and at investigating any differences in the levels of neuropeptides of the trigeminovascular or parasympathetic systems [calcitonin gene-related peptide (CGRP), neurokinin A (NKA) and vasoactive intestinal peptide (VIP) measured by radio-immunoassay methods in external jugular blood] between responders and nonresponders. In all responders to rizatriptan, pain was unilateral, severe, and pulsating, and in five of them at least one sign suggestive of parasympathetic system activation was recorded. Five patients who were non-responders to rizatriptan referred bilateral and non-pulsating pain, even though severe in most of them. CGRP and NKA levels measured before rizatriptan administration were significantly higher in responders than in non-responders ( P < 0.0001 and P < 0.002, respectively). In the five patients with autonomic signs among rizatriptan responders, detectable VIP levels were found at baseline. One hour after rizatriptan administration, a decrease in CGRP and NKA levels was evident in the external jugular venous blood of rizatriptan responders, and this corresponded to a significant pain relief and alleviation of accompanying symptoms. VIP levels were also significantly reduced at the same time in the five patients with autonomic signs. After rizatriptan administration, CGRP and NKA levels in non-responder patients showed less significant variations at all time points after rizatriptan administration compared with rizatriptan responders. The present study, although carried out on a limited number of patients, supports recent clinical evidence of increased trigeminal activation associated with a better triptan response in migraine patients accompanied by parasympathetic activation in a subgroup of patients with autonomic signs. In contrast, the poor response seems to be correlated with a lesser degree of trigeminal activation, lower variations of trigeminal neuropeptides after triptan administration, and no evidence of parasympathetic activation at baseline.

Predictors of Triptan Response in Pediatric Migraine

BACKGROUND

Migraine is common in children and adolescents and can be disabling. Being able to predict which patients will respond to triptans based on their clinical phenotype would be helpful. Adult data suggest cranial autonomic symptoms and aura predict triptan response. This study examined clinical predictors of triptan response in pediatric migraineurs.

METHODS

This chart review study included all patients less than 18 years old with migraine who were seen at the University of California, San Francisco Headache Center in 2014. Univariate χ(2) analyses were performed, followed by multivariate logistic regression modeling.

RESULTS

Of 127 pediatric migraineurs, 70 (55%) had chronic migraine and 24 (19%) had aura. The majority (55%) had at least one cranial autonomic symptom. Of 65 with triptan outcome data, 47 (73%) benefitted from a triptan. In univariate analyses, triptan benefit was seen in 65% with chronic migraine versus 88% with episodic migraine (P = 0.048), 67% with aura versus 74% without (P = 0.66), and 70% with cranial autonomic symptom versus 74% without (P = 0.76). In a multivariate logistic regression model, chronic migraine, aura, and cranial autonomic symptom were not statistically significant predictors of triptan benefit: chronic migraine: 0.25 (0.06-1.04); aura: 0.65 (0.09-4.45); cranial autonomic symptom: 0.75 (0.22-2.52).

CONCLUSIONS

In univariate analysis, individuals with chronic migraine were less likely to benefit from triptans. In contrast to what has been documented in adults, cranial autonomic symptoms and aura did not predict triptan response, although our small sample size limited the study's power. Larger pediatric studies are needed, and future pediatric triptan trials should provide response rates stratified by clinical variables such as aura.

The phenotype of migraine with unilateral cranial autonomic symptoms documents increased peripheral and central trigeminal sensitization. A case series of 757 patients

BACKGROUND

Migraine with unilateral cranial autonomic symptoms (UAS) is a putative migraine endophenotype with convincing response to trigeminal-targeted treatments that still needs a thorough characterization.

OBJECTIVE

The objective of this article is to carefully investigate the clinical phenotype of migraine with UAS in a large group of patients for more accurate migraine diagnoses, improved clinical management, and better outcome prediction.

METHODS

We studied 757 consecutive episodic and chronic migraineurs in a tertiary headache clinic with face-to-face interviews, detailing in depth their lifestyle, sociodemographic and headache characteristics.

RESULTS

Migraineurs with UAS (37.4%) differed from the general migraine population with respect to longer attack duration (OR = 2.47, p < 0.02, having >72-hour long attacks), more strictly unilateral (OR = 3.18, p < 0.001) and severe headache (OR = 1.72, p = 0.011), more frequent allodynia (OR = 3.03, p < 0.001) and photophobia (OR = 1.87, p = 0.019).

CONCLUSIONS

Migraine patients with UAS are characterized not only by symptoms due to intense peripheral trigeminal activation but also to central sensitization. Our study broadens the knowledge on the clinical and phenotypic characteristics of migraine with UAS, suggests pathophysiological implications, and supports the need for future prospective clinical studies.

Pharmacological trials in migraine: it's time to reappraise where the headache is and what the pain is like

Most pharmacological trials deal with migraine as if it were a clinically homogeneous disease, and when detailing its characteristics, they usually report only the presence, or absence, of aura and attack frequency but provide no information on pain location, a non-trivial clinical detail. The past decade has witnessed growing emerging evidence suggesting that individuals with unilateral pain, especially those with associated unilateral cranial autonomic symptoms, are more responsive than others to trigeminal-targeted symptomatic and preventive therapy with drugs such as triptans or botulinum toxin. A simple way for migraine research treatment to take a step forward might be to step back, reappraise, and critically evaluate easily obtainable patient-reported clinical findings along with current knowledge on pain features.

Sumatriptan fast-disintegrating/rapid-release tablets in the acute treatment of migraine

Sumatriptan is the first serotonin (5-hydroxytryptamine [5-HT](1B/1D)) receptor agonist specifically designed for the acute treatment of migraine. A new sumatriptan fast disintegrating/rapid release tablet (FDT/RRT) using RT technology has been developed to enhance tablet disintegration and dispersion in the stomach with the intention of speeding absorption and onset of effect, hence mitigating the effects on the gastrointestinal dysmotility that typically accompanies the attack. Sumatriptan FDT/RRT is bioequivalent to conventional tablets, although it provides slightly faster absorption during early post-dose interval. Clinical trials indicate that sumatriptan FDT/RRT is rapidly effective in terms of freedom from pain and return to normal activities, both with early and late treatment. The drug is well tolerated. In an oral formulation, which is the patients' preferred dosing route, sumatriptan FDT/RRT may therefore constitute an advance in the management of acute migraine attacks.

Unilateral cranial autonomic symptoms in patients with migraine

The aim of this study is to investigate the frequency of unilateral cranial autonomic symptoms during migraine attacks, and to compare the clinical characteristics of migraine patients with and without unilateral cranial autonomic symptoms. One hundred and eighty-six consecutive patients with episodic migraine attacks were prospectively included. Cranial autonomic symptoms of the patients occurred during headache, frequency, duration, severity and character of headache, disease duration, presence of aura, laterality of headache, accompanying symptoms, relation of migraine attacks with menstruation, lesions detected on magnetic resonance images, and family history of migraine were recorded. The patients with and without unilateral cranial autonomic symptoms during headache were compared in terms of above-mentioned parameters. Seventy-seven (41.4 %) patients were observed to develop unilateral cranial autonomic symptoms during migraine attack. Disease duration was longer in the patients with unilateral cranial autonomic symptoms than in those without (p = 0.045). Headache was unilateral in 83.1 % of the patients with unilateral cranial autonomic symptoms (p = 0.001). Pure menstrual or menstrually related migraine attacks were more common in the patients with unilateral cranial autonomic symptoms (p = 0.043) and is thought that menstruation-related hormonal factors might have a triggering role on the trigeminal-autonomic reflex pathway. The longer disease duration in patients with unilateral cranial autonomic symptoms might be associated with the activation of pathophysiological mechanisms that cause cranial autonomic symptoms in time. Frequent unilateral pain in migraine patients with unilateral cranial autonomic symptoms is likely to indicate that the development of autonomic symptoms may share common mechanisms with the pathogenesis of trigeminal autonomic cephalalgias.

Intranasal contact points as a cause of facial pain or headache: a systematic review

BACKGROUND

There is a body of opinion in the clinical literature advocating the removal of intranasal contact points to treat facial pain.

OBJECTIVES

To review the evidence that intranasal mucosal contact points cause facial pain or headache and their removal is therapeutic.

TYPE OF REVIEW

Systematic review.

SEARCH STRATEGY

A systematic search of the available literature was performed using MEDLINE, EMBASE, Cochrane library and NHS Evidence from inception to September 2011. Terms used include facial pain and contact point (3628), rhinologic headache (6) contact point and surgery/endoscopy (38).

EVALUATION METHOD

Inclusion criteria applied. Assessment of papers were undertaken by one reviewer and checked by the second. A narrative review of each study was performed and results recorded in tables.

RESULTS

In one study, 973 consecutive patients with a provisional diagnosis of rhinosinusitis were divided into groups with (42%) and without facial pain. There was a 4% prevalence of nasal contact in both groups, which was unrelated to the presence of facial pain. In another study of 100 patient's coronal paranasal sinus CT scans, 29% had headache and 55% had a contact point but their presence was inversely related to the presence of pain.(1) In a further study, ten healthy volunteers had palpation, adrenaline, substance P and placebo applied to different areas throughout the nasal cavity and none of these stimuli caused facial pain. Nineteen studies were identified where nasal mucosal contact points had been removed surgically for the treatment of facial pain. They were small case series, not randomised and subject to selection bias, had no control group, a limited follow-up and were open to observer bias with level IV evidence. Seven studies had a statistically significant improvement in pain postoperatively compared with preoperative questionnaire results but the majority had residual facial pain.

CONCLUSION

The majority of people with contact points experience no facial pain. The presence of a contact point is not a good predictor of facial pain. The removal of a contact point rarely results in the total elimination of facial pain making the theory that a contact point is responsible unlikely. The improvement in postoperative symptoms following the removal of contact points in some patients may be explained by cognitive dissonance or neuroplasticity. A randomised, controlled and blinded trial with a followed up period of over 12 months is needed to assess the place of surgery in the removal of a contact point for the treatment of facial pain.

Triptan nonresponders: do they exist and who are they?

BACKGROUND

Triptans represent the best treatment option for most migraine attacks, although this is not as well studied as it might be in controlled trials. Their efficacy and tolerability vary, both between agents, and from patient to patient, with about 30%-40% of patients not responding adequately to therapy. As yet unexplained, the failure of one triptan does not predict failure with another, and therefore triptan nonresponders cannot be defined as individuals who have failed a single triptan. Five clinical studies provide evidence that switching from a triptan that is ineffective to a second one can result in effective treatment in a proportion of patients. Systematic studies investigating whether there are patients who do not respond to all triptans in all formulations are lacking.

METHODS

Here we discuss the importance of identifying triptan nonresponders, the literature supporting their existence, and the issues to be resolved to design trials to investigate this.

CONCLUSION

So far, no scientific data about the presence of a triptan nonresponder population are available. We propose a pragmatic study design to assess the existence of this subpopulation, recognizing the complexity of the question and the likelihood that more than one issue is at play in nonresponders.

Migraine-like accompanying features in patients with cluster headache. How important are they?

BACKGROUND

According to the International Classification of Headache Disorders diagnostic criteria, the differences between migraine and cluster headache (CH) are clear. In addition to headache attack duration and pain characteristics, the symptoms accompanying headache represent the key features in a differential diagnosis of these 2 primary headache disorders. Just a few studies of patients with CH exist examining the presence of nausea, vomiting, photophobia, phonophobia, and aura, the features commonly accompanying migraine headache. The aim of this study was to determine the presence of migraine-like features (MF) in patients with CH and establish the significance of these phenomena related to other clinical features and response to treatment.

METHODS

One hundred and fifty-five patients with CH were studied, and 24.5% of them experienced at least one of MF during every CH attack. Nausea and vomiting were the most frequently reported MF. The clinical presentation between CH patients with and without MF was not significantly different with the exception of aggravation of pain by effort (20.6% vs 4.1%) and facial sweating (13.2% vs 0.85%), both more frequent in CH patients with MF.

CONCLUSION

Inferred from the results of our study, the presence of MF in CH patients had no important influence on the diagnosis and treatment of CH patients. The major differences of these 2 primary headache disorders, attack duration, lateralization, and the nature of associated symptoms, as delineated in the International Classification of Headache Disorders, are still useful tools for effective diagnosis.

Rizatriptan in migraineurs with unilateral cranial autonomic symptoms: a double-blind trial

The objective and background is to confirm in a double-blind, placebo-controlled study the high triptan response rates we had previously reported in an open study in migraine patients with unilateral cranial autonomic symptoms. In this randomized, double-blind, placebo-controlled study 80 migraineurs with unilateral cranial autonomic symptoms were assigned to receive rizatriptan 10 mg wafer or placebo (ratio 1:1) and treated for a single moderate or severe migraine attack. The primary endpoints were pain freedom at 2 h and total migraine freedom at 2 h. Secondary endpoints included pain relief, no associated symptoms and sustained pain freedom or relief. Significantly more patients reported pain freedom at 2 h after taking rizatriptan (54 %) than after placebo (8 %) (therapeutic gain 46 % [28 %; 64 %]; P < 0.001). Similarly, significantly more patients reported total migraine freedom at 2 h after rizatriptan (51 %) than after placebo (8 %) (therapeutic gain 43 % [26 %; 61 %]; P < 0.001). Rizatriptan was also more effective than placebo on most secondary endpoints. We confirm in a placebo-controlled study our previous data suggesting that the presence of unilateral cranial autonomic symptoms in migraineurs predicts a positive response to triptans, probably owing to intense trigeminal peripheral afferent activation which strongly recruits peripheral neurovascular 5-HT1B/1D receptors. Acute and preventive pharmacological trials in migraine should focus also on this subset of migraine patients.

Where does a migraine attack originate? In the brainstem

Migraine is a common, paroxysmal, highly disabling primary headache disorder. The origin of migraine attacks is enigmatic. Numerous clinical and experimental results suggest that the activation of distinct brainstem nuclei is crucial in its pathogenesis, but the primary cause of this activation is not fully understood. We conclude that the initialization of a migraine attack can be explained as an altered function of the neuronal elements of the brainstem nuclei. In light of our findings and the literature data, we can assume that migraine is a subcortical disorder of a specific brainstem area.

Nasal reflexes: implications for exercise, breathing, and sex

Nasal patency, with both congestion and decongestion, is affected in a wide variety of reflexes. Stimuli leading to nasal reflexes include exercise; alterations of body position, pressure, and temperature; neurologic syndromes; and dentistry. As anticipated, the vagal and trigeminal systems are closely integrated through nasobronchial and bronchonasal reflexes. However, perhaps of greater pathophysiologic importance are the naso-hypopharyngeal-laryngeal reflexes that become aggravated during sinusitis. None other than Sigmund Freud saw deeply beyond the facial adornment and recognized the deeper sexual tensions that can regulate nasal functions and psychoanalytical status. Wine, women, and song are linked with airflow through the nose-the nose, which by any other name would still smell as sweetly.

Efficacy of sumatriptan tablets in migraineurs self-described or physician-diagnosed as having sinus headache: a randomized, double-blind, placebo-controlled study

BACKGROUND

Many patients and physicians interpret episodic headache in the presence or absence of nasal symptoms as "sinus' headache, while ignoring the possible diagnosis of migraine.

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of sumatriptan succinate 50-mg tablets in patients with migraine presenting with "sinus" headache.

METHODS

A randomized, double-blind, placebo-controlled, multicenter study was conducted in adult (aged 18-65 years) migraine patients presenting with self-described or physician-diagnosed "sinus" headache. From November 2001 to March 2002, patients meeting International Headache Society criteria for migraine (with > or =2 of the following: unilateral location, pulsating quality, moderate or severe intensity, aggravation by moderate physical activity; and > or =1 of: phonophobia and phonophobia, nausea and/or vomiting) and with no evidence of bacterial rhinosinusitis were enrolled and randomized in a 1:1 ratio via computer-generated randomization schedule to receive either 1 sumatriptan 50-mg tablet or matching placebo tablet. The primary efficacy end point was headache response (moderate or severe headache pain reduced to mild or no headache pain) at 2 hours after administration. The presence or absence of migraine-associated symptoms and sinus and nasal symptoms was also measured. Tolerability was assessed through patient-reported adverse events (AEs).

RESULTS

Two hundred sixteen patients with self-described or physician-diagnosed "sinus" headache received a migraine diagnosis and treated 1 migraine attack with sumatriptan 50 mg. The efficacy (intent-to-treat) analysis included 215 patients treated with sumatriptan 50 mg (n = 108; mean [SD] age, 39.6 [12.3] years; mean [SD] weight, 77.7 [17.7] kg; sex, 71% female; race, 69% white) or placebo (n = 107; mean [SD] age, 41.0 [11.3] years; mean [SD] weight 80.7 [20.9] kg; sex, 69% female; race, 64% white). Significantly more patients treated with sumatriptan 50 mg achieved a positive headache response at 2 and 4 hours after administration compared with those treated with placebo (69% vs 43% at 2 hours and 76% vs 49% at 4 hours, respectively; both, P < 0.001). Significantly more sumatriptan-treated patients were free from sinus pain compared with placebo recipients at 2 hours (63% vs 49% placebo, P = 0.049) and 4 hours (77% vs 55%, P = 0.001). All treatments were generally well tolerated. The most common drug-related AEs reported in the sumatriptan and placebo groups, respectively, were dizziness (5% vs < 1%), nausea (3% vs 2%), other pressure/tightness (defined as sense of heaviness; heaviness of upper body, upper extremities; jaw tension; neck tension) (4% vs 0%), and temperature sensations (defined as warm feeling of back of neck, or flushing) (2% vs 0%). No patients experienced any serious AEs.

CONCLUSIONS

Sumatriptan 50-mg tablets were effective and generally well tolerated in the treatment of these patients presenting with migraine headaches that were self-described or physician-diagnosed as sinus headaches.

Prevalence of trigeminal autonomic symptoms in migraine: a population-based study

Epidemiological data on trigeminal unilateral autonomic symptoms in patients with migraine are scarce. The authors wanted to provide a population-based evaluation of the prevalence of unilateral autonomic features in migraine patients and an assessment of the expression of unilaterality of autonomic symptoms and head pain in patients with UAs compared to other migraine patients. A population based sample of 6000 inhabitants of the city of Essen in Germany was screened using a previously validated standard questionnaire. Three thousand three hundred and sixty subjects (56% of a total 6000) responded. 841 subjects had migraine, out of which 226 reported accompanying unilatral auetonomic symptoms (26.9%, CI 95% [23.9-30%]). Unilateral autonomic symptoms in patients with migraine are common and have been widely underestimated in the past. One out of four migraine patients regularly experiences one or more unilateral autonomic symptoms during their attack. Migraine patients with accompanying autonomic symptoms seem to experience their pain more unilateral and more severe than non-UA patients.

Profil autonomique des patients migraineux

OBJECT

Dysfunction of autonomic nervous system (ANS) is implicated in the genesis and persistence of migraine. The objective of this study was to compare autonomic nervous system (ANS) profile of migraineurs during headache-free periods to a group of normal subjects based on cardio-vascular reactivity.

METHODS

Patients with migraine according to the criteria of IHS 2004 were selected for the study. After a 30 min resting blood pressure (BP), the following standard tests were performed: deep-breathing (DB), hand grip (HG) of 15 s and 3 min, valsalva maneuver, echo stress, (ES) and tilt test (TT). Results were compared to 44 normal subjects, age similar, 37 female, (84.1%) using the Student test, with P < 0.005 as significant.

RESULTS

Thirty-two patients (27 female (84.38%), 16-51 years, mean 40.41 +/- 7.8) were studied. Twenty-two patients (69%) had systolic blood pressure below 94 mmHg and 25 patients (78%) had diastolic blood pressure below 60 mmHg. Compared to normal, migraineurs exhibited a significantly higher vagal response (P < 0.001) and a significantly lower alpha sympathetic response, central by using ES as well as peripheral by using HG of 3 min (P < 0.001).

CONCLUSIONS

Autonomic cardiovascular reactivity of patients with migraine showed a vagal hyperactivity and a deficiency of the alpha sympathetic system. This leads to further studies with new therapeutical approaches.

Calcitonin gene-related peptide and its role in migraine pathophysiology

Migraine is a common neurological disorder that is associated with an increase in plasma calcitonin gene-related peptide (CGRP) levels. CGRP, a neuropeptide released from activated trigeminal sensory nerves, dilates intracranial blood vessels and transmits vascular nociception. Therefore, it is propounded that: (i) CGRP may have an important role in migraine pathophysiology, and (ii) inhibition of trigeminal CGRP release or CGRP-induced cranial vasodilatation may abort migraine. In this regard, triptans ameliorate migraine headache primarily by constricting the dilated cranial blood vessels and by inhibiting the trigeminal CGRP release. In order to explore the potential role of CGRP in migraine pathophysiology, the advent of a selective CGRP receptor antagonist was obligatory. The introduction of di-peptide CGRP receptor antagonists, namely BIBN4096BS (1-piperidinecarboxamide, N-[2-[[5-amino-1-[[4-(4-pyridinyl)-1-piperazinyl]carbonyl] pentyl] amino]-1-[(3,5-dibromo-4-hydroxyphenyl) methyl]-2-oxoethyl]-4-(1,4-dihydro-2-oxo-3(2H)-quinazolinyl)-, [R-(R*,S*)]-), is a breakthrough in CGRP receptor pharmacology and can be used as a tool to investigate the role of CGRP in migraine headaches. Preclinical investigations in established migraine models that are predictive of antimigraine activity have shown that BIBN4096BS is a potent CGRP receptor antagonist and that it has antimigraine potential. Indeed, a recently published clinical study has reported that BIBN409BS is effective in treating acute migraine attacks without significant side effects. The present review will discuss mainly the potential role of CGRP in the pathophysiology of migraine and the various treatment modalities that are currently available to target this neuropeptide.

Subcutaneous Sumatriptan Induces Changes in Frequency Pattern in Cluster Headache Patients

OBJECTIVES

To document the relationship between the use of subcutaneous (SQ) sumatriptan (sum) and a change in frequency pattern of cluster headache (CH) in six patients. To discuss the clinical and pathophysiological implications of this observation in the context of available literature.

BACKGROUND

Treatment with SQ sum may cause an increase in attack frequency of CH but data from literature are scant and controversial.

METHODS

Six CH sum-naïve patients (three episodic and three chronic according to the International Headache Society (IHS) criteria) are described.

RESULTS

All six patients had very fast relief from pain and accompanying symptoms from the drug but they developed an increase in attack frequency soon after using SQ sum. In all patients, the CH returned to its usual frequency within a few days after SQ sum was withdrawn or replaced with other drugs. Five patients were not taking any prophylactic treatment and SQ sum was the only drug prescribed to treat their headache.

CONCLUSIONS

Physicians should recognize the possibility that treatment of CH with SQ sum may be associated with an increased frequency of headache attacks.

The pathophysiology of primary headache

Headache research has been a productive area, and understanding of primary headache pathophysiology has increased greatly. There are many more questions that need to be answered to gain a better understanding of the primary headache process. For the clinician,there is value in understanding the pathophysiology of primary headache, because this understanding can help improve diagnostic acumen and shape treatment plans to provide patients with more effective treatment.