Headache disorders, characterized by recurrent headache, are among the most common disorders of the nervous system. The aim of this study was to document epidemiological and economic burden due to headache globally and in India and suggest a public health approach to address headache disorders for India. We reviewed the available literature on burden due to headache, its management using a primary health care approach and health system barriers, with special emphasis on India. Globally, it has been estimated that prevalence of current headache disorder (symptomatic within last year) among adults is about 50%, around 30% report migraine and headache on 15 or more days every month affects 1.7–4% people. The Global Burden of Disease Study 2016 estimated that migraine caused 45·1 million (95% UI 29·0–62·8) and tension-type headache 7·2 million (95% UI 4·6–10·5) years of life lived with disability. Limited data available in India support such high burden. These studies also indicate high diagnostic and treatment gaps for headache disorders in India. Major challenges in addressing headache disorders effectively in India are low perceived severity, absence of burden data, lack of standard treatment protocols for headache disorders and primary care models for neurological disorders in developing country context. There needs to be a better appreciation of the burden and a public health approach among all stakeholders, if burden of headache disorders is to be addressed effectively in India.

Background: Key structures for the pathophysiology of primary headache disorders such as migraine, cluster headache, and other trigeminal autonomic cephalalgias were identified by imaging in the past years. Objective: Available data on functional imaging in primary headache disorders are summarized in this review. Material and Methods: We performed a MEDLINE search on December 27^th, 2020 using the search terms “primary headache” AND “imaging” that returned 453 results in English, out of which 137 were labeled reviews. All articles were evaluated for content and relevance for this narrative review. Results: The structure depicted most consistently using functional imaging in different states of primary headaches (without and with pain) was the posterior hypothalamus. Whole-brain imaging techniques such as resting-state functional resonance imaging showed a wide-ranging association of cortical and subcortical areas with human nociceptive processing in the pathophysiological mechanisms underlying the different TACs. Similarities of distinct groups of primary headache disorders, as well as their differences in brain activation across these disorders, were highlighted. Conclusion: The importance of neuroimaging research from clinical practice point of view remains the reliable and objective distinction of each individual pain syndrome from one another. This will help to make the correct clinical diagnosis and pave the way for better and effective treatment in the future. More research will be necessary to fulfill this unmet need.

Background: Disability from migraine has a profound impact on the world's economy. Research has been ongoing to identify biomarkers to aid in diagnosis and treatment. Objective: The aim of this study was to highlight the purported diagnostic and therapeutic migraine biomarkers and their role in precision medicine. Methods: A comprehensive literature search was conducted using PubMed, Google Scholar, and clinicaltrials.gov using keywords: “migraine” OR “headache” combined with “biomarkers” OR “marker.” Other keywords included “serum,” “cerebral spinal fluid,” “inflammatory,” and “neuroimaging.” Results: After a review of 88 papers, we find the literature supports numerous biomarkers in the diagnosis of migraine. Therapeutic biomarkers, while not as extensively published, highlight calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide-38 (PACAP-38) as biomarkers with the most substantiated clinical relevance. Genetic markers mainly focusing on gene mutations with resultant biochemical alterations continue to be studied and show promise. Conclusion: Although there are several proposed biomarkers for migraine, continued research is needed to substantiate their role in clinical practice.

Background: Migraine is the most prevalent neurological disorder and the leading cause of disability in individuals under 50 years of age. Two types of migraine therapies have been defined: acute therapy (abortive or symptomatic treatment), the purpose of which is to interrupt migraine attacks, and preventive treatment (prophylactic treatment), the purpose of which is to reduce the frequency and severity of migraine attacks. Objective: This paper reviews research advances in new agents for acute therapy of migraine. Material and Methods: This review provides an overview of emerging new drugs for acute treatment of migraine based on clinical evidence and summarizes the milestones of different stages of clinical development. Results: Two new formulations of sumatriptan, DFN-11 (3 mg doses of subcutaneous sumatriptan) and DFN-02 (a nasal spray of sumatriptan 10 mg and a permeation-enhancing excipient), have been developed, and both of them showed a fast-onset action with efficacy for acute treatment of migraine with fewer adverse events. New drug discovery programs shifted the focus to the development of ditans, a group of antimigraine drugs targeting 5-HT_1F receptors. Only lasmiditan has progressed to phase III clinical trials and was finally approved by the Food and Drug Administration (FDA) for acute migraine treatment. The other target for acute therapy is CGRP receptor antagonists, namely, gepants. Ubrogepant and rimegepant demonstrated statistically significant efficacy, and both were recently approved by the FDA. These 5-HT_1F receptor agonists and CGRP receptor antagonists did not cause vasoconstriction, offering advantages over the current mainstay of specific acute migraine treatment. Conclusions: Overall, these new agents have expanded the available acute therapies for migraine treatment and will likely change the strategy with which we treat patients with migraine in the future.

Background: An acute attack of migraine, incapacitates the migraineurs, and is widely prevalent. And to warden off its symptoms, recently two groups of drugs have been approved and launched. Objective: The aim of this systematic review and indirect meta-analysis is to evaluate and summarize the effectiveness of these pharmacological interventions in managing the aforesaid disease. Material and Methods: An extensive literature search was done through Cochrane library, Pub Med, clincialtrials.gov, for a period of 5 years (2015–2020), using key words: lasmiditan; ubrogepant; rimegepant; and acute migraine. Randomized double-blind phase III clinical trials, published in English language, were included which explored the efficacy and safety of these drugs. The outcomes of this meta-analysis included proportion of patients' headache, most bothersome symptoms free, and no disability at all at 2 h post-dose, with sustained pain freedom 2-24 h, and experiencing any adverse event. An indirect network meta-analysis was also conducted to determine the comparative effectiveness of these drugs. Results: A total of seven RCTs involving 7266 patients were included. In general, the new drugs demonstrated better result in all the efficacy parameters. The adverse events were observed in treatment group compared to placebo. While in the indirect comparison, lasmiditan emerged to be superior in all the outcomes, except for sustained pain freedom 2-24 h (rimegepant was better). The adverse events were more with lasmiditan. Conclusion: All the newer drugs have shown significant improvement in the outcomes analyzed. Lasmiditan appears to be superior among the newer drugs in efficacy; however it has more adverse effects.

Background: Migraine is a common primary headache disorder and Episodic migraine is characterized by the occurrence of up to 14 headache days in a month. The preventive treatment of migraine is useful in patients with frequent migraine attacks, impaired activities of daily living, failure of acute pain management, disabling aura and limitations in the use of acute treatment. It is aimed at reducing headache frequency and intensity, improve response to acute treatment of migraine and improve the quality of life. Aim: To analyze the evidence for the efficacy and tolerability of preventive oral drugs used in the management of episodic migraine. Methods: A narrative review of the references were reviewed by searching the literature for the articles published in PubMed in English language using all the following MeSH keywords “preventive treatment”, “preventive oral treatment”, AND “episodic migraine”, “migraine”. Results: Out of articles identified in the search, 38 articles were reviewed for evidence and summarized. The various oral drugs used in the prevention of episodic migraine are antihypertensives (beta-blockers, calcium channel blockers and Angiotensin-converting enzyme inhibitors/Angiotensin receptor blockers), antidepressants (tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors), antiepileptic drugs (valproic acid, topiramate, lamotrigine) and other miscellaneous agents. HURT questionnaire and HALT 30 index are useful in assessing response to treatment in the follow up of migraine patients. Conclusion: An appropriately chosen oral drug is useful in the preventive treatment of episodic migraine. In patients, who fail to respond to the preventive treatment, it is essential to review the diagnosis of migraine, titrate the dosage and duration of preventive treatment and ensure patient compliance. In those patients who fail to respond to monotherapy, polytherapy is a useful option to be considered.

Background: Medications targeting the calcitonin gene-related peptide (CGRP) pathway are exciting and novel therapeutic options in the treatment of migraine. Objective: In this article, we have reviewed the role of these CGRP monoclonal antibodies in patients with episodic migraine. Materials and Methods: We did an extensive literature search for all phase 2 and 3 studies involving CGRP monoclonal antibodies in episodic migraine. Results: Erenumab, fremanezumab, galcanezumab, and eptinezumab have all undergone phase 3 trials and have been found to be effective for episodic and chronic migraine. They have the advantage of being targeted therapies for migraine with very favorable adverse effect profiles comparable to placebo. Importantly, they are effective in subgroups of patients who have failed previous preventive therapies. Conclusion: Increasing use of these medications will certainly revolutionize the treatment and outlook for patients with migraine all over the world.

Background: Chronic migraine is an under-recognized and under-treated disorder. A greater understanding of the pathophysiology of migraine and transformation to chronic migraine has led to the first targeted treatments for chronic migraine. In this review, we review current approaches to the diagnosis and management of chronic migraine and discuss recent and emerging novel therapies. Objective: The aim of this study was to provide an update on the diagnosis and management of chronic migraine. Methods and Material: The PubMed database was searched for relevant articles published on or before October 2020. Results and Conclusions: Chronic migraine is an under-recognized and under-treated disorder. Prompt diagnosis and appropriate management can lead to a significant improvement in the quality of life with subsequent socioeconomic benefits.

Background: Medication overuse headache (MOH) is one of the highly disabling headache disorder and affects about 1% of the population of the world. It is associated with the development of headache for 15 days or more, with consumption of acute symptomatic medications for 10–15 days (depending on the class of drug, like, simple analgesics, triptans, and opioids) in a month, used for relief of headache for three or more months, in a known patient of primary headache disorder. Objective: The aim of this study was to review the topic of MOH and present the details of this disorder with an emphasis on recent updates in the field of pathophysiology and treatment. Material and Methods: Literature search was performed in the PubMed/MEDLINE and Cochrane database with appropriate keywords and relevant full-text articles were reviewed for writing this article. Results: Over the years, the concept of MOH has evolved, although the exact pathophysiology is still being explored. In a susceptible individual interplay of genetics, change in pain pathways, changes in areas of the brain associated with the perception of pain, and changes in the neurotransmitters have been implicated. It has to be differentiated from other secondary chronic daily headache disorders, by a careful history, targeted examination, details of intake of medications. Treatment predominantly involves patient education, removal of the offending agent, and initiation of prophylactic medications for primary headache disorder in the outpatient or inpatient services. Conclusions: MOH is a secondary headache disorder, which should be considered in any chronic headache patient. There are various pathophysiological mechanisms attributed to its development. Management includes educating the patients about the disorder, detoxification, and prophylactic therapy.

Background: Migraine is a common neurological disorder with significant morbidity and disability. There is growing evidence that migraine is associated with cardiovascular diseases and stroke. Objective: The aim of this study was to provide an update on the association of migraine with some common vascular diseases in persons suffering from the disease and discuss the clinical implications. Methods and Materials: We searched PUBMED database using the MeSH terms “Stroke”, “Coronary Artery Disease”, “Myocardial Ischemia”, “Atrial Fibrillation”, “White Matter” and “Dementia, Vascular”, in combination with “Migraine Disorders”, “Migraine with Aura” and “Migraine without Aura” and reviewed the relevant studies. We studied articles mostly in English for the past 10 years, without excluding older articles that were relevant to this review. We also searched the reference lists of articles obtained and included some insightful reviews on 'Migraine and Vascular Risk'. Results: The association between migraine and vascular diseases is strong and consistent for ischemic stroke and migraine with aura especially in young women, with oral contraceptive use and smoking. Although literature reports a higher prevalence of obesity, dyslipidemia, and family history of cardiovascular diseases in migraineurs, the 'migraine-vascular' connection persists in models where the traditional vascular risk factors are adjusted, implicating a migraine-specific pathophysiology at work. There is some evidence linking an adverse vascular risk factor profile to incident myocardial infarction in people with migraine. The association with hemorrhagic stroke is more variable. Conclusion: Although the absolute effect of migraine on 'vascular risks' is small, good practice parameters dwell on treating and reducing existing cardiovascular risk factors through lifestyle modification, encouraging smoking cessation, and advocating the wise use of agents like ergot alkaloids and oral contraceptives, after a risk-benefit analysis.

Background: The complex relationship between migraine and epilepsy has frequently been described to represent a clinical and electrographic “borderland.” These two conditions share clinical expressions such as paroxysmal and chronic nature, as well as semiology, particularly visual phenomenon. Objective: We aimed to review the current literature on the overlapping phenomena of migraine and epilepsy. Materials and Methods: We searched the PubMed for relevant literature and conducted a narrative review on migraine and epilepsy. Results: Migraine and epilepsy share a complex and pathophysiologically intriguing relationship. The International Classification of Headache Disorders, 3^rd edition (ICHD-3) makes diagnostic provisions for migraine aura–triggered seizures (Subchapter 1.4.4) and headache attributed to epileptic seizure (Subchapter 7.6), the latter being further categorized as 7.6.1 Ictal epileptic headache, and 7.6.2  post-ictal headache. Neurological conditions such as certain channelopathies and epilepsy syndromes exhibit both conditions within their phenotypic spectrum, suggesting shared genetic and molecular underpinnings. Diagnostic confusion may arise, particularly between occipital epilepsy and the visual aura of migraine. Antiseizure medications may be effective for the treatment of migraines that occur in concert with epilepsy. Conclusions: Migraine and epilepsy share several clinical features and have intertwined genetic and molecular underpinnings, which may contribute to common pathogenesis. Electroencephalography may be useful as a diagnostic tool in selected cases.

Background: While understanding the pathophysiology of migraine has led to CGRP-based treatments, other potential targets have also been implicated in migraine. Objectives: To catalog new promising targets for the treatment of migraine. Methods: We completed a literature review focusing on 5HT_1F, PACAP, melatonin, and orexins. Results: The 5HT_1F receptor agonist lasmiditan, following two positive randomized placebo-controlled trials, was FDA-approved for the acute treatment of migraine. PACAP-38 has shown analogous evidence to what was obtained for CGRP with its localization in key structures, provocation tests, and positive studies when antagonizing its receptor in animal models, although a PAC-1 receptor monoclonal antibody study was negative. Melatonin has undergone several randomized controlled trials showing a positive trend. Filorexant is the only dual orexin receptor antagonist, which was tested in humans with negative results. Conclusions: Further and ongoing studies will determine the utility of these new therapies with lasmiditan and melatonin having demonstrated efficacy for the treatment of migraine.

Objective: The goal of this manuscript was to provide a comprehensive review of the surgical treatment for migraine headaches with a focus on trigger points and their clinical presentations, and to emphasize the importance of appropriate patient selection. Background: Migraine is a prevalent neurological disease with headache being a disabling component of it. Surgical treatment for migraine headache became available two decades ago, which is based on proper identification and the deactivation of the specific trigger sites in the head and neck area. Design: This manuscript reviews the discovery and evolution of migraine surgery with changes in patients' selection throughout the years. Conclusion: Patients with migraine headaches who do not respond or cannot tolerate the medical treatment might benefit from trigger site deactivation surgery. The success of the surgery is closely related to proper identification of trigger point (s) and close collaboration with a neurologist or a headache specialist. This collaboration would enhance patients' positive outcomes and help to rule out other causes of the headache.

Background: Migraine is a common form of primary neurologic headache. Many patients are chronic migraineurs and suffer from a significant disability and adverse effects of drugs. There are various surgical options available to treat migraines, including peripheral neurectomies. Objective: To study the surgical and functional outcomes of migraine surgeries using peripheral neurectomies and compare them with conservatively treated patients. Materials and Methods: Migraine patients who had a unilateral onset pain were given local bupivacaine block at the suspected trigger site, and those who were relieved were given the option for surgery. In the operative group, the peripheral nerve of the trigger site was lysed under local anesthesia. The conservative group was continued with the standard treatment. Evaluations with a baseline and 6 months visual analog score (VAS), migraine headache index (MHI), migraine disability assessment test (MIDAS), and pain self-efficacy questionnaire (PSEQ) scores were done. Results: A total of 26 patients got benefitted with the local bupivacaine block, out of which 13 underwent surgery. At baseline, the VAS, MHI, MIDAS, and PSEQ scores were similar in both the groups. The operative group had significant (P < 0.001) improvement in all these parameters 6 months after the surgery. All patients of the operative group got free from prophylactic migraine treatment; however, 11 out of 13 patients still needed occasional  use of analgesics. There was one complication of transient temporal numbness. Conclusion: Migraine surgery using peripheral neurectomies was more effective than chronic drug treatment in appropriately selected patients.

Background: Tension-type headache (TTH) is the most common form of primary headache. Objective: The aim of this study was to document and summarize the advances in the understanding of TTH in terms of pathogenesis and management. Material and Methods: We reviewed the available literature on the pathogenesis and management of TTH by searches of PubMed between 1969 and October 2020, and references from relevant articles. The search terms “tension-type headache”, “episodic tension-type headache”, chronic tension-type headache, “pathophysiology”, and “treatment” were used. Results: TTH occurs in two forms: episodic TTH (ETTH) and chronic TTH (CTTH). Unlike chronic migraine, CTTH has been less thoroughly studied and is a more difficult headache to treat. Frequent ETTH and CTTH are associated with significant disability. The pathogenesis of TTH is multifactorial and varies between the subtypes. Peripheral mechanism (myofascial nociception) and environmental factors are possibly more important in ETTH, whereas genetic and central factors (sensitization and inadequate endogenous pain control) may play a significant role in the chronic variety. The treatment of TTH consists of pharmacologic and non-pharmacologic approaches. Simple analgesics like NSAIDs are the mainstays for acute management of ETTH. CTTH requires a multimodal approach. Preventive drugs like amitriptyline or mirtazapine and non-pharmacologic measures like relaxation and stress management techniques and physical therapies are often combined. Despite these measures, the outcome remains unsatisfactory in many patients. Conclusion: There is clearly an urgent need to understand the pathophysiology and improve the management of TTH patients, especially the chronic form.

Background: Cluster headache is a highly disabling primary headache disorder which is widely described as the most painful condition a human can experience. Aim: To provide an overview of the clinical characteristics, epidemiology, risk factors, differential diagnosis, pathophysiology and treatment options of cluster headache, with a focus on recent developments in the field. Methods: Structured review of the literature on cluster headache. Results: Cluster headache affects approximately one in 1000 of the population. It is characterised by attacks of severe unilateral head pain associated with ipsilateral cranial autonomic symptoms, and the tendency for attacks to occur with circadian and circannual periodicity. The pathophysiology of cluster headache and other primary headache disorders has recently become better understood and is thought to involve the hypothalamus and trigeminovascular system. There is good quality evidence for acute treatment of attacks with parenteral triptans and high flow oxygen; preventive treatment with verapamil; and transitional treatment with oral corticosteroids or greater occipital nerve injection. New pharmacological and neuromodulation therapies have recently been developed. Conclusion: Cluster headache causes distinctive symptoms, which once they are recognised can usually be managed with a variety of established treatments. Recent pathophysiological understanding has led to the development of newer pharmacological and neuromodulation therapies, which may soon become established in clinical practice.

Paroxysmal Hemicrania (PH) is classified under trigeminal autonomic cephalalgia (TAC) as per the International Classification of Headache Disorders (ICHD). Since the first description by 0ttar Sjaastad and Inge Dale in 1974, PH has been reported by many authors. A greater understanding of PH phenotype and pathophysiology has resulted in the evolution of its diagnostic criteria, and management. We tabulated major case series of PH to describe the epidemiology, clinical features and recent updates of PH. PH is a rare headache characterized by daily, multiple paroxysms of unilateral, short-lasting (mean duration <20 minutes), side-locked headache in the distribution of ophthalmic division of trigeminal nerve with associated profound cranial autonomic symptoms. Recent ICHD classification added “restlessness” to the criteria for PH. Pain should completely respond to indomethacin to fulfil the diagnostic criteria of PH. PH should be differentiated from cluster headache, SUNCT/SUNA, and other short-lasting side-locked headaches. Trigeminal afferents possibly produce pain in PH and trigeminal-autonomic reflex explains the occurrence of autonomic features. Recently, a “permissive” central role of the hypothalamus is unveiled based on functional imaging studies. Other Cox-2 inhibitors, topiramate, calcium-channel blockers, epicranial nerve blocks have been shown to improve headache in some patients of PH who cannot tolerate indomethacin. Hypothalamic deep brain stimulation has been used in treatment-refractory cases.

Background: Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) are rare and disabling primary headache disorders that are subtypes of Short-lasting unilateral neuralgiform headache attacks (SUNHA). Aim: The aim of this narrative review was to provide a comprehensive update on headache phenotype, pathophysiology, and various treatment options available for SUNCT and SUNA. Methods: References for this review were identified by searches of articles published in the English language in PubMed between 1978 and October 2020 using “short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)”, “short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA)”, “short-lasting unilateral neuralgiform headache attacks (SUNHA)”, “trigeminal autonomic cephalalgias” as keywords in various combinations. Results: Of a potential 1103 articles, seven case series describing clinical characteristics of SUNCT/SUNA patients were identified for this review. For symptomatic/secondary SUNCT/SUNA, 53 individual case reports, and one case series were reviewed. One placebo-controlled trial and 11 open-label case series that evaluated various medical and surgical treatments in SUNCT/SUNA were also reviewed. Available literature suggests that SUNCT and SUNA are subtypes of the same disorder characterized by severe side locked short duration headache with ipsilateral prominent cranial autonomic symptoms and signs. Pathophysiology may involve both peripheral and central mechanisms. Lamotrigine is the most effective preventive therapy while intravenous lidocaine is the most efficacious drug as transitional therapy for severe disabling attacks. Surgical options including microvascular decompression in those having neurovascular conflict, occipital nerve stimulation, and hypothalamic deep brain stimulation can be alternative treatment options for medically refractory patients.

Background: Hemicrania continua (HC) is not uncommon in clinical practice, and several large case series have been published in the recent past. Objectives: This review provides an overview of the recent advancement in different aspects of HC. Methods: We reviewed the articles published on HC in the last 2 decades. Results: HC constitutes 1.7% of patients with headache in the clinics. It presents with unilateral continuous background pain with periodic exacerbations, usually accompanied by cranial autonomic features and restlessness. The continuous background headache is the most consistent and central feature of HC. Although the duration of exacerbations varies from a few seconds to a few weeks, the frequency ranges from >20 attacks/day to one attack in several months. The background pain is mild to moderate in intensity and does not hamper routine activity. Patients and physicians frequently ignore the basal pain, and a case of HC is misdiagnosed as other headaches, depending on the pattern of exacerbations. The exacerbation mimics several primary headaches and neuralgias. There are about 75 cases of secondary HC, due to 29 different pathologies. Although an absolute response to indomethacin is part of the diagnostic criteria, a subset of patients may respond to several other drugs. Headache reappears immediately on skipping a single dose of effective drug. Several surgical procedures have been tried in patients who are intolerant to indomethacin. Conclusion: Misdiagnosis of HC is common. Continuous background pain and response to indomethacin are two essential features for the diagnosis of HC.

Background: Other primary headaches make up group 4.0 of the International Classification of Headache Disorders third edition (ICHD-3). This group includes a clinically varied group of headache entities whose pathophysiology is not well understood and whose treatments are based on open-label reports. Objective: To review and update the uncommon primary headaches included under group 4.0 in ICHD-3. Methods: We reviewed the headache disorders listed under group 4.0 of ICHD-3 for the clinical features, diagnostic criteria, and management, and described recent updates of these relatively rare disorders. Results: The entities included in this group have a characteristic presentation in practice. Some of them are activity-related and can be provoked by Valsalva maneuver (primary cough headache), some by prolonged exercise (primary exercise headache), and some by sexual excitation (primary headache associated with sexual activity); primary thunderclap headache has also been included here because all the above-listed entities can sometimes present in thunderclap fashion too. Two of the entities in this group 4.0 are linked to direct physical stimuli viz. cold stimulus headache and external pressure headache. Also included in this group are primary stabbing headaches and nummular headaches that are presumed to be due to the involvement of the terminal branches of the sensory nerves supplying the scalp and are, therefore, termed “epicranial headaches.” Hypnic headache syndrome and new daily persistent headache are included here as “miscellaneous headaches” because we still do not know enough about their causation. Conclusion: The headache disorders included under group 4.0 in ICHD-3 are uncommon, heterogeneous entities, which may pose diagnostic and management challenges to the physicians. The diagnosis may be missed owing to a lack of familiarity.

Background: Headache accounts for a significant number of cases presenting to the Emergency Department (ED) and has a high societal cost, contributed by recurrent ED and clinic visits, and unnecessary diagnostic tests. Objective: This review article covers the important clinical tools needed to evaluate headaches in both adults and children in the ED. Methods: Medline/PubMed was searched using the keywords “Emergency department”, “headache”, “adult”, “pediatric”, “clinical assessment”, “diagnosis” and “treatment”, in the title or abstract. The search covers the period from 1 January 1990 to 31 December 2019. Results: The articles selected were based on their relevancy to the objective of this review article. Additional relevant publications were identified from article references lists. Conclusion: The emergency physician plays a key role in differentiating between primary and secondary headaches. Within the limited ED resources, appropriate diagnostic testing should be used to identify the life-threatening headaches. This will ensure patients are given the appropriate evidence-based pharmacological therapy and holistic management.

Background: Migraine is a common disabling primary headache condition. Although strives have been made in treatment, there remains an unmet need for safe, effective acute, and preventative treatments. The promising concept of neuromodulation of relevant neuronal targets in a noninvasive fashion for the treatment of primary headache disorders has led to the trial of numerous devices over the years. Objective: We aimed to review the evidence on current neuromodulation treatments available for the management of primary headache disorders. Methods: Randomized controlled trial as well as open-label and real-world studies on central and peripheral cephalic and noncephalic neuromodulation modalities in primary headaches were critically reviewed. Results: The current evidence suggests a role of single-pulse transcranial magnetic stimulation, supraorbital nerve stimulation, and remote noncephalic electrical stimulation as migraine abortive treatments, with stronger evidence in episodic rather than in chronic migraine. Single-pulse transcranial magnetic stimulation and supraorbital nerve stimulation also hold promising evidence in episodic migraine prevention and initial positive evidence in chronic migraine prevention. More evidence should clarify the therapeutic role of the external vagus nerve stimulation and transcranial direct current stimulation in migraine. However, external vagus nerve stimulation may be effective in the acute treatment of episodic but not chronic cluster headache, in the prevention of hemicrania continua and paroxysmal hemicrania but not of short-lasting neuralgiform headache attacks. The difficulty in setting up sham-controlled studies has thus far prevented the publication of robust trials. This limitation along with the cost of these therapies has meant that their use is limited in most countries. Conclusion: Neuromodulation is a promising nonpharmacological treatment approach for primary headaches. More studies with appropriate blinding strategies and reduction of device cost may allow more widespread approval of these treatments and in turn increase clinician's experience in neuromodulation.

Background: Cervicogenic headache is a distinct type of headache described in 1980s by Sjaastad, a Norwegian neurologist. It is a not so uncommon headache, which is usually under-diagnosed resulting in suboptimal quality-of-life. Objective: The aim of this study was to review the current recommendations on diagnosis and management of cervicogenic headache. Methods and Material: A PubMed search was done for the recent articles on 'cervicogenic headache' published in English literature with the aim of recognizing the current perspectives on cervicogenic headache. Results: The diagnosis of cervicogenic headache is based on clinical criteria mentioned by the International Headache Society (IHS) and Cervicogenic Headache International Study Group (CHISG). Cervical nerve block may confirm the nociceptive source in majority of cases and is included in CHISG criteria. Non-invasive diagnostic methods like echogenicity of muscles, diffusion tensor imaging (DTI) and single-photon emission tomography (SPECT) are proposed by some authors for avoiding complications associated with blocks. Mainstay of management is physical therapy. Surgical interventions for cervical degenerative disease may relief an associated headache but such interventions are not performed solely for cervicogenic headache. Conclusion: Headaches with a cervical spine nociceptive source are increasingly being recognized. Current diagnostic criteria and management options are reviewed here.

Background: Trigeminal neuralgia (TN) is a painful condition, often leading to poor quality of life. Objective: The aim of this review was to discuss the various treatment modalities for the medical management of TN. Materials and Methods: We reviewed the available literature on TN in clinical databases including PubMed, Google Scholar, and the Cochrane Database of Systematic Reviews, with a specific focus on the pharmacological treatment and newer drugs under development for the treatment of TN. Results: Carbamazepine (CBZ) is the gold standard of treatment for TN. The first-line drugs for the treatment of TN are CBZ and oxcarbazepine (OXC). A proportion of cases (30%) are initially resistant to the first-line drugs. Alternative drugs need to be considered if the first-line drugs are not well tolerated or become ineffective with prolonged therapy. The second-line drugs comprise lamotrigine, baclofen, gabapentin, and pregabalin used as monotherapy or in combination with CBZ/OXC. Botulinum toxin A may be a promising presurgical option. Newer drug like vixotrigine has shown good results in phase two randomized control trials. About 50% of cases develop treatment resistance to oral drugs over the subsequent years of therapy and require surgical options. Conclusion: The first-line drugs for the treatment of TN (irrespective of the age group or type) are CBZ and OXC. Combination therapy with second-line or other drugs may become necessary with poor response to CBZ/OXC, or if adverse events occur. Patients should be offered surgical options if there is poor response or tolerance to the medical therapy.

Background: Trigeminal neuralgia (TN) is a devastating condition causing significant patient discomfort and morbidity hampering quality of life. Of the many treatment options available, microvascular decompression (MVD) of the trigeminal nerve is widely performed. However, the procedure is not risk-free. Objective: The study aimed to describe our experience of treating TN via MVD and long-term follow-up of the patients treated by this modality. Materials and Methods: It is a 5-year retrospective analysis of the database of patients with idiopathic TN treated with MVD at our institute. A total of 106 patients fulfilling the criteria of idiopathic TN by International Classification of Headache Disorders, 3^rd ed.ition and available for follow-up for at least 1-year post-procedure were included in the study. Results: Of the 106 patients, 58 (54.7%) were female and 48 (45.3%) were male with a mean age of 55 years (range 22–75 years). Vascular compression of the trigeminal nerve was seen in all cases; arterial compression in 82%, both artery and vein 14.5% while unidentified vessels were the culprit in 3.8% of the patients. There were no intra- or post-operative deaths. The best response was achieved at 1 month following the procedure where 85% of the patients achieved excellent outcomes. Conclusion: In experienced hands, MVD is still a safe and cost-effective modality over a myriad of treatment options available for TN in patients of all ages. The absence of adhesions, indentations, and distortion of the trigeminal nerve are positive predictors of excellent outcomes in the long run.

Background: Greater and lesser occipital neuralgias are primary neuralgias that are relatively uncommon, where the pain is felt in the distribution of these nerves. Objective: This review paper was intended to describe the features and management of occipital neuralgia in the context of a challenging case. Material and Methods: We looked at succinct literature from the past 30 years. We compared the features of our challenging case given in the current literature. In addition, an overview of the current literature is provided. Results: The case, although proved to be a diagnostic challenge, we were able to reach a conclusion and render the patient almost complete pain relief by conservative management modalities. It proved to be a rare presentation of occipital neuralgia with unusual pain distribution, and we are able to describe a literature-based explanation for this entity to be a diagnostic and management challenge. Conclusion: Primary headaches, i'n general, are a group of headache disorders that require exquisite diagnostic skills. The clinical history is a key factor when making an accurate diagnosis, and to establish an appropriate management plan.

Background: Occipital neuralgia (ON) is a primary headache disorder characterized by sharp, shooting, or electric shock-like pain in the distribution of the greater, lesser, or third occipital nerves. Aim: To review the existing literature on the management of ON and to describe our technique of an endoscopic-assisted approach to decompress the GON proximally in areas of fibrous and muscular compression, as well as distally by thorough decompression of the occipital artery from the nerve. Methods: Relevant literature on the medical and surgical management of ON was reviewed. Literature on the anatomical relationships of occipital nerves and their clinical relevance were also reviewed. Results: While initial treatment of ON is conservative, peripheral nerve blocks and many surgical management approaches are available for patients with pain refractory to the medical treatment. These include greater occipital nerve blocks, occipital nerve stimulation, Botulinum toxin injections locally, pulsed radiofrequency ablation, cryoneuroablation, C-2 ganglionectomy, and endoscopic-assisted ON decompression. Conclusion: Patients of ON refractory to medical management can be benefitted by surgical approaches and occipital nerve blocks. Endoscopic-assisted ON decompression provides one such approach for the patients with vascular, fibrous or muscular compressions of occipital nerves resulting in intractable ON.

Background: The proximity of sensory neurons in the upper cervical spinal cord to the trigeminal nucleus caudalis (TNC) neurons and the convergence of sensory input to TNC neurons from both cervical and trigeminal fibers underscore the rationale of using greater occipital nerve block (GON-block) for acute and preventive treatment in various headache disorders. Objective: The aim of this study was to critically review the existing literature regarding the safety and efficacy of GON-block in various headache disorders. Methods: We searched the eligible studies in English by searching in PubMed till December 31, 2020 for randomized controlled trials (RCTs), observational studies, open-label studies, case series, and case reports on the efficacy and the safety of GON-block for the treatment of headache disorders using the keywords “greater occipital nerve block”, “headache” and “treatment”. Studies using combination of GON-block and other peripheral nerve blocks (PNBs) and C2/C3 blocks were excluded. Results: Seventy-two eligible studies were reviewed. Based on RCTs and open-label studies, good evidence of the efficacy of GON-block was found for migraine, cluster headache (CH), post-dural puncture headache (PDPH), cervicogenic headache (CGH), and occipital neuralgia (ON). The analgesic effect of GON-block outlasted its anesthetic effect by days to weeks. Evidence for acute and short-term (transitional) treatment was more robust than for long-term prevention. GON-block was found to be safe and the treatment-emergent adverse effects (TEAEs) were generally mild and transient. Conclusion: GON-block is a useful modality of treatment in various headache disorders because of many attractive features such as its early effect in reducing the severity of pain, sustained effect following a single injection, easy technique, minimum invasiveness, minimum TEAE, no drug-to-drug interactions, and negligible cost.