Indomethacin-responsive headaches-A narrative review

Prevalence of primary stabbing headache: A meta-analysis

OBJECTIVES/BACKGROUND

This study was undertaken to assess the prevalence of primary stabbing headache (PSH) among adult patients seeking medical attention for headache in a clinic-based setting. PSH is a primary headache disorder and is one of the representatives of indomethacin-responsive cephalalgias. The epidemiology of PSH in adult patients assessed for headache in a tertiary care setting remains not well established.

METHODS

PubMed, Embase, MEDLINE, and ScienceDirect databases were thoroughly searched for observational studies published between January 1, 1988, and August 9, 2024, that reported the relative frequency of PSH among adult patients evaluated for headache in a clinic-based setting. The Meta-Analysis of Observational Studies in Epidemiology guidelines were strictly followed by the study's design. Risk of bias was assessed using the Joanna Briggs Institute Checklist for Studies Reporting Prevalence Data. The study's protocol was preregistered on PROSPERO (ID: CRD42024573776).

RESULTS

Of the initial 1153 records, 15 articles (n = 35,904 individuals) met all of the eligibility criteria. Most of the studies revealed a low risk of bias. The prevalence of PSH among adult patients evaluated for headache in a tertiary care setting was 1.6% (95% confidence interval [CI] = 0.7-3.4, 95% prediction interval [PI] = 0.00-0.29), with substantial heterogeneity (I2 = 98.42) noted across the studies. PSH was diagnosed more often in females than in males (1.6%, 95% CI = 0.8-3.2, 95% PI = 0.00-0.18 vs. 0.5%, 95% CI = 0.2-1.1, 95% PI = 0.00-0.06). The mean age at onset of PSH was 41.6 years (SD = 13.7), and the mean delay time of diagnosis was 64.6 months (SD = 73.9).

CONCLUSION

Our results showed that PSH is a rare headache disorder among adults evaluated for headache in a clinic-based setting. Moreover, PSH is typically diagnosed in the early fourth decade of life and predominantly in females.

The crucial role of neutrophil extracellular traps and IL-17 signaling in indomethacin-induced gastric injury in mice

The homeostasis of gastric mucosa is extremely delicate. Neutrophils, the most abundant immune cells in human circulation, are regarded crutial in the regulation of gastric mucosal immune response. Non-steroidal anti-inflammatory drugs (NSAIDs) induced gastric injury is the second major reason for gastric ulcers. The relations between neutrophils and Indomethacin-induced gastric injury are not fully understood. A mouse model of gastric injury was established using Indomethacin, followed by proteomic analysis (raw data are available via ProteomeXchange with identifier PXD058482). GO functional annotations and KEGG pathway enrichment analysis were conducted on significant differential proteins. The formation of neutrophil extracellular traps (NETs) was observed using ELISA and immunofluorescence. TEM, Western blot and Real-time PCR were applied to observe programmed death of gastric epithelial cells (GECs), and ELISA was conducted to measure levels of TNF-α and IL-1β in the gastric tissue. Deoxyribonuclease 1 (DNase 1), a NETs inhibitor, was administered intraperitoneally to inhibit NETs formation. In vitro, neutrophils were isolated from peripheral blood of mice and co-cultured with mouse GECs cell line, different dosage of Indomethacin were added to the culture dish, the levels of inflammatory factors, formation of NETs and GECs programmed death were assessed in vitro. Poly morphonuclear neutrophils (PMN) were extracted from mouse peripheral blood and single-cell RNA-sequencing (scRNA-seq) was further applied (raw data are available via Genome Sequence Archive with identifier CRA020950) to explore the intracellular mechanism of NETs formation. ELISA and immunofluorescence were performed to validate expression of IL-17 signaling pathway. After Indomethacin gavage, obvious gastric injury was observed. Proteomic analysis indicated that NETs formation played a crucial role in Indomethacin-induced gastric injury. Compared to control group, Indomethacin treatment resulted in NETs formation, elevated levels of TNF-α and IL-1β and GECs programmed death. Inhibition of NETs significantly reduced inflammatory factor levels and mitigated gastric injury caused by indomethacin. In vitro, 200 µL, 400 µL and 600 µL of Indomethacin caused excessive NETs formation in neutrophils. Besides, Indomethacin-induced NETs formation led to GECs programmed death in vitro. scRNA-seq revealed that neutrophils enrichment in the peripheral blood of Indomethacin-induced gastric injury and IL-17 signaling might be the key intracellular of NETs formation. Expressions of neutrophil IL-17R and concentration of IL-17 were significantly higher in model group. NETs formation is pivotal in Indomethacin-induced gastric injury, contributing to programmed cell death of GECs and inflammation; IL-17 signaling might be the key intracellular mechanism of NETs formation.

Indomethacin-responsive refractory headache: Two case reports in children after hemispherectomy for Rasmussen's encephalitis

BACKGROUND

Indomethacin-responsive headaches occur in youth and include primary headache syndromes such as hemicrania continua and paroxysmal hemicrania. Both are trigeminal autonomic cephalalgias (TACs). In pediatrics TACs are rare. Moreover, they may differ in their phenotypes and response to indomethacin compared to adults. Secondary causes for side-locked headaches can have vascular, neoplastic, and inflammatory etiologies, emphasizing the importance of imaging in the evaluation of these headache types. Post-craniotomy indomethacin-responsive headaches have been described in adults, but not in children.

METHODS

Written consent was obtained from the patients' families and written assent from the two children for publication.

RESULTS

We report the course of two children, both with a history of Rasmussen's encephalitis treated with functional hemispherectomies, who subsequently developed debilitating, side-locked, medically refractory headaches several months after surgery. Headaches were on the same side of their encephalitis and surgery. In both instances, the headaches were exquisitely and rapidly responsive to indomethacin. Headache freedom was maintained on low doses of indomethacin (0.14-0.5 mg/kg/day).

CONCLUSION

In cases of refractory side-locked headaches following a craniotomy or neuroinflammatory condition in children, one may consider indomethacin as a treatment option after evaluation for other secondary etiologies.

How can you manage an indomethacin-responsive headache in someone who cannot take indomethacin?

PURPOSE OF REVIEW

Paroxysmal hemicrania and hemicrania continua are rare primary headache disorders which are distinguished by an absolute response to indomethacin. As a matter of importance, no guidelines have been proposed for alternative therapeutic options in case of indomethacin intolerance. The purpose of this review is to provide an update on the current findings, especially focusing on the past 18 months, in the treatment of both paroxysmal hemicrania and hemicrania continua and to provide proposed management recommendations based on summarized evidence.

RECENT FINDINGS

Apart from well recognized gastrolesive effects of indomethacin, a substantial number of patients may suffer from neuropsychiatric adverse reactions. Recent studies demonstrated that melatonin, which has been known for its effectiveness for hemicrania continua, is also useful for paroxysmal hemicrania. Promising nonpharmacological treatment option, which is noninvasive vagus nerve stimulation, has been shown to be beneficial for both indomethacin-responsive headache disorders allowing the reduction of indomethacin dosage. Although the data on substitutive medication choice for indomethacin are currently scarce, the most consistent results have been repeatedly achieved with acemethacin, selective COX-2 inhibitors, and anticonvulsants. However, considering the crucial role of pathophysiology, research investigating the efficacy of drugs targeting the trigemino-vascular system activation, as well as controlled trials assessing the efficacy involving the aforementioned therapeutic options are still vague.

SUMMARY

In spite of numerous reports suggesting reliable alternatives to indomethacin, the consensus on pharmacological therapy guidelines for indomethacin-responsive headache disorders has not yet been reached. Further research and agreement from the experts' standpoint are needed for an establishment of reliable treatment recommendations.

How pharmacology can aid in the diagnosis of mental disorders

The precise diagnosis of mental disorders constitutes a formidable problem. Mental disorders are currently diagnosed based on clinical symptoms, which are often subjective. Various drug classes, traditionally referred to as "antidepressants," "antipsychotics" and "mood stabilizers" are then used empirically to treat affected patients. The previous decade has witnessed an increasing extension of the use of drug classes beyond their traditional indications (e.g., "antidepressants" in the treatment of anxiety disorders). Therefore, we would like to initiate a discussion in the pharmacological and psychiatric research communities on an alternative classification of mental disorders: Instead of using the traditional categorical classification of mental disorders physicians should rather diagnose symptoms (e.g., anhedonia) without bias to a traditional categorization (e.g., depression). The appropriate most effective drugs are then selected based on these symptoms. Depending on the responsiveness of the patient towards a given drug X, the disease should be classified, e.g., as drug X-responsive disease. This approach will also help us elucidate the still poorly understood molecular mechanisms underlying mental disorders, i.e., drugs can also be viewed and used as molecular diagnostic tools. In several fields of medicine, drugs are already used as molecular diagnostic tools. Thus, there is already precedence for the concept proposed here for mental disorders.

Co-morbid Indomethacin-Responsive Headaches in a Woman in Her Late 60s With Paroxysmal Hemicrania and Hypnic Headache: A Case Report

Paroxysmal hemicrania (PH) and hypnic headache (HH) are rare indomethacin-responsive headache syndromes. This case report details the new onset of both disorders in a woman in her late 60s. One headache type presented as severe pain centered on the right eyebrow, lasting 30 minutes, occurring more than 8 times daily, and associated with ipsilateral lacrimation and rhinorrhea. The second type was a right frontal severe pain, with onset at 4 a.m., occurring only during sleep, lasting 30 minutes, and with no associated factors. The patient's response to indomethacin for both headache types was confirmed through an unblinded ABAB study design: complete resolution of headaches during indomethacin use and recurrence upon discontinuation. This case highlights the rarity of co-morbid indomethacin-responsive headaches and underscores the diagnostic and therapeutic challenges associated with these conditions.

Primary Headache Associated with Sexual Activity: A Review of the Literature

PURPOSE OF REVIEW

This review summarizes the evolution in diagnosis, evaluation, and treatment of primary headache associated with sexual activity (PHASA).

RECENT FINDINGS

Despite increased access to patient information and advances in imaging, the pathophysiology of PHASA remains not fully understood. There are many secondary headaches that may present with headache during sexual activity, and a thorough workup is indicated to rule out potentially life-threatening etiologies. Many recent case series discuss the efficacy of known treatments of PHASA, as well as suggest other potential therapies for this condition including the newer CGRP-targeted therapies. Headaches during sexual activity can be worrisome events which necessitate urgent evaluation, particularly when presenting with sudden-onset and severe "thunderclap" headaches. A thorough workup including imaging should be conducted to rule out etiologies such as subarachnoid hemorrhage, reversible cerebral vasoconstrictive syndrome (RCVS), vasospasm, and dissection. PHASA is commonly comorbid with migraine, tension-type headache, exertional headache, and hypertension. PHASA can present as a dull headache that progresses with sexual excitement, or an explosive headache at or around orgasm. Pain is primarily occipital, diffuse, and bilateral. The headaches are discrete, recurrent events with bouts that typically self-resolve, but may also relapse and remit or continue chronically in some patients. PHASA can be treated preemptively with indomethacin and triptans administered prior to sexual activity, or treated prophylactically with beta-blockers, topiramate, and calcium channel blockers. CGRP-targeted therapies may provide relief in PHASA based on a few case reports, but there are no randomized controlled trials looking at specific efficacy for these therapies.

Indomethacin-Responsive Headache Disorders

OBJECTIVE

This article describes the clinical features and treatment of the indomethacin-responsive headache disorders paroxysmal hemicrania and hemicrania continua.

LATEST DEVELOPMENTS

Both paroxysmal hemicrania and hemicrania continua are treated with indomethacin at the lowest clinically useful dose. It has recently become clear that some patients with either condition may respond to treatment with noninvasive vagus nerve stimulation, which can be both indomethacin sparing and, in some cases, headache controlling. Given the lifelong nature of both paroxysmal hemicrania and hemicrania continua, brain imaging with MRI is recommended when the conditions are identified, specifically including pituitary views.

ESSENTIAL POINTS

Paroxysmal hemicrania and hemicrania continua are indomethacin-responsive headache disorders that offer a rewarding and unique opportunity to provide marked clinical improvement when recognized and treated appropriately. These disorders share the final common pathway of the trigeminal-autonomic reflex, with head pain and cranial autonomic features, and are differentiated pathophysiologically by the pattern of brain involvement, which can be seen using functional imaging. They have distinct differential diagnoses to which the clinician needs to remain alert.

Association of atopic dermatitis and headache disorder: a systematic review and meta-analyses

Background

Growing evidence suggests that headache disorders and atopic dermatitis share similar pathological mechanisms and risk factors. The aim of this study was to assess the risk for headache disorders in patients with atopic dermatitis.

Methods

We systematically searched the PubMed and Embase databases from inception to December 1, 2023, for observational studies that examined risk of migraine in subjects with atopic dermatitis. Risk estimates from individual studies were pooled using random-effects models.

Results

Ten studies with 12,717,747 subjects were included in the meta-analysis. Our results showed that patients with atopic dermatitis were associated with a higher risk of headache disorder (OR, 1.46, 95% CI = 1.36-1.56; P < 0.001; I2 = 98%) or migraine (OR, 1.32, 95% CI = 1.18-1.47; P < 0.001; I2 = 98.9%). Most of the results of the subgroup analyses were consistent with the overall results.

Conclusion

The findings of this meta-analysis suggest that atopic dermatitis is a potential risk indicator for headache disorder or migraine. Further studies are still needed to verify our findings due to the substantial heterogeneity in our analyses.

Refractory primary and secondary headache disorders that dramatically responded to combined treatment of ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks and non-invasive vagus nerve stimulation: a case series

In 1981, Devoghel achieved an 85.6% success rate in treating patients with treatment-refractory cluster headaches with alcoholization of the pterygopalatine ganglion (PPG) via the percutaneous suprazygomatic approach. Devoghel's study led to the theory that interrupting the parasympathetic pathway by blocking its transduction at the PPG could prevent or treat symptoms related to primary headache disorders (PHDs). Furthermore, non-invasive vagus nerve stimulation (nVNS) has proven to treat PHDs and has been approved by national regulatory bodies to treat, among others, cluster headaches and migraines.In this case series, nine desperate patients who presented with 11 longstanding treatment-refractory primary headache disorders and epidural blood patch-resistant postdural puncture headache (PDPH) received ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks (PPGB), and seven also received nVNS. The patients were randomly selected and were not part of a research study. They experienced dramatic, immediate, satisfactory, and apparently lasting symptom resolution (at the time of the writing of this report). The report provides the case descriptions, briefly reviews the trigeminovascular and neurogenic inflammatory theories of the pathophysiology, outlines aspects of these PPGB and nVNS interventions, and argues for adopting this treatment regime as a first-line or second-line treatment rather than desperate last-line treatment of PDPH and PHDs.

Epidemiology and clinical features of paroxysmal hemicrania: A systematic review and meta-analysis

OBJECTIVE

To assess the prevalence or relative frequency of paroxysmal hemicrania and its clinical features in the adult general population and among adult patients evaluated for headache in tertiary care.

BACKGROUND

Paroxysmal hemicrania is a rare trigeminal autonomic cephalalgia with characteristic attacks of headache, associated cranial autonomic symptoms and signs, and an absolute response to indomethacin. Its epidemiological burden remains unknown in both the adult general population and among adult patients evaluated for headache in a tertiary care setting. Moreover, the frequencies of the clinical features associated with paroxysmal hemicrania have not been well established.

METHODS

A literature search of PubMed and Embase was conducted from January 1, 1988, to January 20, 2023. Eligible for inclusion were observational studies reporting the point prevalence or relative frequency of paroxysmal hemicrania or its clinical features in the adult general population or among adult patients evaluated for headache in tertiary care. Two independent investigators (M.J.H. and J.G.L.) performed the title, abstract, and full-text article screening. Each included study's risk of bias was critically appraised using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Estimates of prevalence or relative frequency were calculated using a random-effects meta-analysis. The between-study heterogeneity was assessed using the I2 statistic and further explored with meta-regression. This study was pre-registered on PROSPERO (identifier: CRD42023391127).

RESULTS

A total of 17 clinic-based studies and one population-based study met the eligibility criteria. Importantly, an overall high risk of bias was observed across the eligible studies. The relative frequency of paroxysmal hemicrania was estimated to be 0.3% (95% CI, 0.2%-0.5%) among adult patients evaluated for headache in tertiary care with considerable heterogeneity (I2  = 76.4%). No cases with paroxysmal hemicrania were identified among 1,838 participants in a population-based sample. Moreover, the most prevalent cranial autonomic symptoms were lacrimation (77.3% [95% Cl, 62.7%-87.3%]), conjunctival injection (75.0% [95% Cl, 60.3%-85.6%]), and nasal congestion (47.7% [95% Cl, 33.6%-62.3%]).

CONCLUSIONS

Our findings suggest that paroxysmal hemicrania is a rare disorder among adults evaluated for headache in tertiary care, while its prevalence in the general population remains unknown. Further studies focusing on the clinical features of paroxysmal hemicrania are warranted.

The evolutionary meaning of migraine

INTRODUCTION

Migraine's astonishing prevalence and preserved genetic background contrast with the definition of a disease and the biological meaning of experiencing recurrent, severe headache attacks is still puzzling.

METHODS

To provide a comprehensive explanation of the migraine evolutionary meaning, we review (i) the putative role of the autonomic nervous system in migraine attacks, (ii) the inter-ictal autonomic, functional, and metabolic signature of migraine patients, (iii) the bio-behavioral perspective of pain, and (iv) the allostatic perception of migraine chronification.

RESULTS

Migraineurs have inter-ictal cortical hyperexcitability and metabolic dysfunction that predisposes to brain energetic imbalance. Multiple precipitating factors may lead to brain energy consumption over the migraine attack generation threshold. In response, the brain engenders adaptive, evolutionary conserved, autonomic-behavior responses through the antidromic activation of the trigeminovascular system. The sickness behavior and severe pain experienced during migraine attacks result in avoiding mental and physical activity, allowing brain energy restoration. Chronic exposure to stressors may result in an allostatic overload, leading to maladaptive chronic activation of these responses. In this bio-behavioral perspective, the chronification of migraine should be envisioned as a pathological process, whereas the migraine itself should not.

CONCLUSION

Migraine has an evolutionary (Darwinian) meaning.

Paroxysmal hemicrania and hemicrania continua: Review on pathophysiology, clinical features and treatment

BACKGROUND

Paroxysmal hemicrania and hemicrania continua are indometacin-sensitive trigeminal autonomic cephalalgias, a terminology which reflects the predominant distribution of the pain, observable cranial autonomic features and shared pathophysiology. Understanding the latter is limited, both by low prevalence and the intricacies of studying brain function, requiring multimodal techniques to glean insights into such disorders. Similarly obscure is the curious response to indometacin. This review will address what is currently known about pathophysiology, the rationale for the current classification and, features which may confound the diagnosis, such as lack of cranial autonomic symptoms and those which are typically associated with migraine such as nausea, photophobia, phonophobia and aura. Despite these characteristics, a dramatic response to indometacin, which is not seen in migraine nor the other trigeminal autonomic cephalalgias , provides the hallmark of the diagnosis. The main clinical differential for paroxysmal hemicrania is based on temporal pattern and lies between cluster headache and short-lasting-neuralgiform headache attacks with tearing or additional cranial autonomic symptoms. For hemicrania continua it is more challenging as the main differential for which the disorder is often treated is migraine. A prior episodic pattern, often days at a time, and the tendency to exacerbation with analgesics will further deflect from the diagnosis. The relevance of this is that there is little overlap in therapeutics between paroxysmal hemicrania and hemicrania continua and other headache disorders and there are limited effective alternatives to indometacin. The most effective are other non-steroidal anti-inflammatory drugs including the newer COX-II inhibitors. Even though early reports suggest that a higher indometacin dose-requirement may herald a secondary precipitating pathology, this does not seem to be the case, with syndrome and response to treatment being similar with the primary disorder. In this context imaging of new onset paroxysmal hemicrania or hemicrania continua and implication of the results will be discussed as will alternative treatment options.

Primary Cough Headache

PURPOSE OF REVIEW

In this review article, we summarize the most recent findings and observations in patients experiencing primary cough headache.

RECENT FINDINGS

Recent studies draw attention to further characterization of patients with primary cough headache in a pulmonology clinic. There have also been recent case studies describing new therapy considerations, including noninvasive vagus nerve stimulation and lumbar punctures. Primary cough headache has been a recognized entity since as early as 1932. Patients generally report a sudden onset, sharp headache lasting a few hours that is precipitated by Valsalva maneuver or coughing. It remains an uncommon diagnosis, and secondary causes are crucial to rule out with imaging studies. Additionally, there can be an overlap with other primary headache disorders such as primary exercise headache and headache associated with sexual activity, thus requiring a detailed history. Many hypotheses exist regarding the pathophysiology including relative pressure gradients and a crowded posterior fossa. Generally, patients are responsive to indomethacin, but more recent case reports have suggested benefits of other medications and procedures that may offer patients an alternative option, including vagus nerve stimulation, lumbar punctures, and beta blockers. Future case series and studies should focus on management of these patients, with a specific focus on individuals who do not tolerate indomethacin.

Hemicrania Continua: An Update

PURPOSE OF REVIEW

Hemicrania Continua (HC) is a rare and disabling primary headache disorder that is characterized by persistent, unilateral headache with ipsilateral, cranial autonomic symptoms and restlessness or agitation. The diagnosis requires patients to experience an absolute response to therapeutic doses of indomethacin.

RECENT FINDINGS

HC is diagnosed in in about 1.8% of adult patients who were evaluated for headache in tertiary care services, albeit this estimate should be interpreted with caution. The most prevalent accompanying symptoms appear to be lacrimation, conjunctival injection and restlessness or agitation. However, the available literature is limited by methodologic issues, and the current diagnostic criteria lack clarity on what defines absolute response to indomethacin. More rigorous studies are thus needed to improve our understanding of HC which, in turn, will facilitate better disease management in clinical practice. Here, we provide a comprehensive overview of HC, including its epidemiology, clinical presentation, diagnostic evaluation, and management.

Hydrogen Sulfide-Releasing Indomethacin-Derivative (ATB-344) Prevents the Development of Oxidative Gastric Mucosal Injuries

Hydrogen sulfide (H2S) emerged recently as an anti-oxidative signaling molecule that contributes to gastrointestinal (GI) mucosal defense and repair. Indomethacin belongs to the class of non-steroidal anti-inflammatory drugs (NSAIDs) and is used as an effective intervention in the treatment of gout- or osteoarthritis-related inflammation. However, its clinical use is strongly limited since indomethacin inhibits gastric mucosal prostaglandin (PG) biosynthesis, predisposing to or even inducing ulcerogenesis. The H2S moiety was shown to decrease the GI toxicity of some NSAIDs. However, the GI safety and anti-oxidative effect of a novel H2S-releasing indomethacin derivative (ATB-344) remain unexplored. Thus, we aimed here to compare the impact of ATB-344 and classic indomethacin on gastric mucosal integrity and their ability to counteract the development of oxidative gastric mucosal injuries. Wistar rats were pretreated intragastrically (i.g.) with vehicle, ATB-344 (7-28 mg/kg i.g.), or indomethacin (5-20 mg/kg i.g.). Next, animals were exposed to microsurgical gastric ischemia-reperfusion (I/R). Gastric damage was assessed micro- and macroscopically. The volatile H2S level was assessed in the gastric mucosa using the modified methylene blue method. Serum and gastric mucosal PGE2 and 8-hydroxyguanozine (8-OHG) concentrations were evaluated by ELISA. Molecular alterations for gastric mucosal barrier-specific targets such as cyclooxygenase-1 (COX)-1, COX-2, heme oxygenase-1 (HMOX)-1, HMOX-2, superoxide dismutase-1 (SOD)-1, SOD-2, hypoxia inducible factor (HIF)-1α, xanthine oxidase (XDH), suppressor of cytokine signaling 3 (SOCS3), CCAAT enhancer binding protein (C/EBP), annexin A1 (ANXA1), interleukin 1 beta (IL-1β), interleukin 1 receptor type I (IL-1R1), interleukin 1 receptor type II (IL-1R2), inducible nitric oxide synthase (iNOS), tumor necrosis factor receptor 2 (TNFR2), or H2S-producing enzymes, cystathionine γ-lyase (CTH), cystathionine β-synthase (CBS), or 3-mercaptopyruvate sulfur transferase (MPST), were assessed at the mRNA level by real-time PCR. ATB-344 (7 mg/kg i.g.) reduced the area of gastric I/R injuries in contrast to an equimolar dose of indomethacin. ATB-344 increased gastric H2S production, did not affect gastric mucosal PGE2 content, prevented RNA oxidation, and maintained or enhanced the expression of oxidation-sensitive HMOX-1 and SOD-2 in line with decreased IL-1β and XDH. We conclude that due to the H2S-releasing ability, i.g., treatment with ATB-344 not only exerts dose-dependent GI safety but even enhances gastric mucosal barrier capacity to counteract acute oxidative injury development when applied at a low dose of 7 mg/kg, in contrast to classic indomethacin. ATB-344 (7 mg/kg) inhibited COX activity on a systemic level but did not affect cytoprotective PGE2 content in the gastric mucosa and, as a result, evoked gastroprotection against oxidative damage.

Non-invasive neuromodulation of the cervical vagus nerve in rare primary headaches

Primary headache disorders can be remarkably disabling and the therapeutic options available are usually limited to medication with a high rate of adverse events. Here, we discuss the mechanism of action of non-invasive vagal nerve stimulation, as well as the findings of the main studies involving patients with primary headaches other than migraine or cluster headache, such as hemicrania continua, paroxysmal hemicrania, cough headache, or short-lasting neuralgiform headache attacks (SUNCT/SUNA), in a narrative analysis. A bibliographical search of low-prevalence disorders such as rare primary headaches retrieves a moderate number of studies, usually underpowered. Headache intensity, severity, and duration showed a clinically significant reduction in the majority, especially those involving indomethacin-responsive headaches. The lack of response of some patients with a similar diagnosis could be due to a different stimulation pattern, technique, or total dose. The use of non-invasive vagal nerve stimulation for the treatment of primary headache disorders represents an excellent option for patients with these debilitating and otherwise refractory conditions, or that cannot tolerate several lines of preventive medication, and should always be considered before contemplating invasive, non-reversible stimulation techniques.

Evaluation of Biological Activity Exerted by Dibenzo[b,e]Thiophene-11(6H)-One on Left Ventricular Pressure Using an Isolated Rat Heart Model

BACKGROUND

Some studies show that some Dibenzo derivatives can produce changes in the cardiovascular system; however, its molecular mechanism is not very clear.

OBJECTIVE

The objective of this investigation was to evaluate the inotropic activity of ten Dibenzo derivatives (compounds 1 to 10) on either perfusion pressure or left ventricular pressure.

METHODS

Biological activity produced by the Dibenzo derivatives on either perfusion pressure or coronary resistance was evaluated using an isolated rat heart. In addition, the molecular mechanism of biological activity produced by compound 4 (Dibenzo[b,e]thiophene-11(6H)-one) on left ventricular pressure was determined using both Bay-k8644 and nifedipine as pharmacological tools in an isolated rat heart model.

RESULTS

The results showed that Dibenzo[b,e]thiophene-11(6H)-one increases perfusion pressure and coronary resistance at a dose of 0.001 nM. Besides, other data display that Dibenzo[b,e]thiophene-11(6H)-one increases left ventricular pressure in a dose-dependent manner (0.001 to 100 nM) and this effect was similar to biological activity produced by Bay-k8644 drug on left ventricular pressure. However, the effect exerted by Dibenzo[b,e]thiophene-11(6H)-one was inhibited in the presence of nifedipine at a dose of 1 nM.

CONCLUSIONS

All these data suggest that Dibenzo[b,e]thiophene-11(6H)-one increase left ventricular pressure through calcium channel activation. In this way, Dibenzo[b,e]thiophene-11(6H)-one could be a good candidate as positive inotropic agent to heart failure.

Prevalence and clinical features of hemicrania continua in clinic-based studies: A systematic review and meta-analysis

OBJECTIVE

To estimate the relative frequencies of hemicrania continua and its clinical features in adult patients who were evaluated for headache in a clinic-based setting.

METHODS

PubMed and Embase were searched for observational, clinic-based studies published between 1 January 2004 and 1 February 2022, that reported on the relative frequencies of hemicrania continua and its clinical features. Two independent investigators (HMA and SA-K) screened titles, abstracts, and full text-articles. A random-effects meta-analysis was conducted to estimate pooled relative frequencies of hemicrania continua and its clinical features across clinic-based studies.

RESULTS

Eleven clinic-based studies were deemed eligible for inclusion. Of these, eight studies reported on the relative frequency of hemicrania continua among adult patients (n = 9854) who were evaluated for headache in a tertiary care unit. The pooled relative frequency of hemicrania continua was found to be 1.8% (95% CI; 1.0-3.3). Considerable heterogeneity was noted across studies (I² = 89.8%). The three most common symptoms associated with hemicrania continua were lacrimation (72.3%), conjunctival injection (69.8%), and restlessness/agitation (60.2%).

CONCLUSION

The findings of this meta-analysis suggest that there is limited epidemiologic data on the relative frequencies of hemicrania continua and its clinical features. Standardized data acquisition and reporting are needed to estimate prevalence rates more accurately and to better understand epidemiologic patterns. This, in turn, should increase awareness of the impact that hemicrania continua has in clinical practice.

Recent Advances and Updates in Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgias (TACs) are discrete primary headache disorders, characterized by severe unilateral head pain, typically trigeminal distribution, with ipsilateral cranial autonomic symptoms. The conditions within this group are hemicrania continua, cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache with autonomic symptoms. Several advances have been made in understanding the pathogenesis and evolving treatment options in TACs. This review will outline the advances and updates in each TAC.

Hemicrania continua secondary to neurogenic paravertebral tumor- a case report

OBJECTIVES

Hemicrania continua (HC) is one of the trigeminal autonomic cephalalgias (TAC), where sympathetic dysfunction and autonomic dysfunction resulting in parasympathetic over activation with some evidence of sympathetic inhibition have been suggested as probable causes. However, cases of hemicrania continua secondary to sympathetic dysfunction due to neurogenic paravertebral tumor impinging on the sympathetic chain has not been previously reported. In this case, the probability of the sympathetic dysfunction was more likely based on the clinical features and management.

CASE PRESENTATION

A 23-year-old female presented with a chief complaint of right unilateral pain in the retro-bulbar, head and facial region for the past three years. An initial MRI of the brain was negative, whereas an MRI of the spine was advised to rule out a cervicogenic origin of the pain. The MRI revealed a well-defined mass lesion within right paravertebral region at T3 indicative of a neurogenic tumor. The patient was diagnosed with probable hemicrania continua secondary to neurogenic tumor impinging on adjacent sympathetic chain. A trial of indomethacin 75 mg/day was advised, which provided complete relief of the headache. The patient was referred to a neurologist for management of the neurogenic tumor.

CONCLUSIONS

Headache disorders may be secondary to pathologies and comprehensive evaluation and accurate diagnosis are essential. Knowledge of neuroanatomy is paramount to understand and explain underlying pathophysiological mechanisms. Multidisciplinary management is essential in complex orofacial cases.