Pharmacogenomic study-A pilot study of the effect of pharmacogenomic phenotypes on the adequate dosing of verapamil for migraine prevention.

OBJECTIVE: To investigate factors affecting the efficacy and tolerability of verapamil for migraine prevention using individual pharmacogenomic phenotypes. BACKGROUND: Verapamil has a wide range of dosing in headache disorders without reliable tools to predict the optimal doses for an individual. METHODS: This is a retrospective chart review examining adults with existing pharmacogenomic reports at Mayo Clinic who had used verapamil for migraine. Effects of six cytochrome P450 phenotypes on the doses of verapamil for migraine prevention were assessed. RESULTS: Our final analysis included 33 migraine patients (82% with aura). The mean minimum effective and maximum tolerable doses of verapamil were 178.2(20-320) mg and 227.9(20-480) mg. A variety of CYP2C9, CYP2D6, and CYP3A5 phenotypes were found, without significant association with the verapamil doses after adjusting for age, sex, body mass index, and smoking status. CONCLUSIONS: We demonstrated a wide range of effective and tolerable verapamil doses used for migraine in a cohort with various pharmacogenomic phenotypes.

Visual Snow: Updates and Narrative Review.

PURPOSE OF REVIEW: Visual snow (VS) involves visualization of innumerable dots throughout the visual field, sometimes resembling "TV static." Patients who experience this symptom may also have additional visual symptoms (e.g., photophobia, palinopsia, floaters, and nyctalopia) with a pattern now defined as visual snow syndrome (VSS). This manuscript describes both VS and VSS in detail and provides an updated review on the clinical features, pathophysiology, and optimal management strategies for these symptoms. RECENT FINDINGS: VS/VSS may be primary or secondary to a variety of etiologies, including ophthalmologic or brain disorders, systemic disease, and medication/hallucinogen exposure. Evaluation involves ruling out secondary causes and mimics of VS. Increasing evidence suggests that VSS is a widespread process extending beyond the visual system. Pathophysiology may involve cortical hyperexcitability or dysfunctional connectivity of thalamocortical or attention/salience networks. VSS is typically a benign, non-progressive syndrome and can be managed with non-medicine strategies. Though no medication provides complete relief, some may provide partial improvement in severity of VS.

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management.

PURPOSE OF REVIEW: The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus. RECENT FINDINGS: Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

Lacrimal Neuralgia: A Case Report and Comprehensive Review of the Literature.

PURPOSE OF REVIEW: Lacrimal neuralgia is a rare periorbital neuralgia. To date, only nine cases have been reported in the literature. Herein, we report a case and a comprehensive overview of the entity with a focus on the differential diagnosis of lacrimal neuralgia. Additionally, we propose putative diagnostic criteria for this rare neuralgia based on cases that have been reported. RECENT FINDINGS: Among the ten cases of lacrimal neuralgia reported (including the one in this review), seven out of ten were idiopathic, and the other three were considered secondary. Most patients reported stabbing and shooting pain that was either paroxysmal or continuous. The most effective therapy was nerve block for seven patients and pregabalin for three patients. The most important clues to differentiate lacrimal neuralgia from other causes of periorbital pain include pain topography and pain with features suggestive of neuralgia. The core feature of lacrimal neuralgia is neuralgic pain located in the area supplied by the lacrimal nerve, and the etiology could be primary or secondary. Responsiveness to anesthetic blockade might better serve as a confirmational, rather than mandatory, criterion for diagnosis.

Narrative review of migraine management in patients with renal or hepatic disease.

OBJECTIVES/BACKGROUND: Treatment of migraine in the setting of either renal or hepatic disease can be daunting for clinicians. Not only does the method of metabolism have to be considered, but also the method of elimination/excretion of the parent drug and any active or toxic metabolites. Furthermore, it is difficult to think about liver or kidney disease in isolation, as liver disease can sometimes contribute to impaired renal function and renal disease can sometimes impair hepatic metabolism, through the cytochrome P450 system. METHODS: A detailed search for terms related to liver disease, renal disease, and migraine management was performed in PubMed, Ovid Medline, Embase, and the Cochrane Library.For each medication, product labels were retrieved and reviewed using the US FDA website, with additional review of IBM Micromedex, LiverTox, and the Renal Drug Handbook. RESULTS: This manuscript provides an overview of migraine drug metabolism and how it can be affected by liver and renal impairment. It reviews the standard terminology recommended by the US Food and Drug Administration for the different stages of hepatic and renal failure. The available evidence regarding the use of abortive and preventative medicines in the setting of organ failure is discussed in detail, including more recent therapies such as lasmiditan, gepants, and calcitonin gene-related peptide antibodies. CONCLUSIONS: For acute therapy, the use of NSAIDS should be limited, as these carry risk for both severe hepatic and renal disease. Triptans can be selectively used, often with dose guideline adjustments. Ubrogepant may be used in severe hepatic disease with dose adjustment and lasmiditan can be used in end stage renal disease. Though non-medicine strategies may be the most reasonable initial approach, many preventative medications can be used in the setting of hepatic and renal disease, often with dose adjustment. This review provides tables of guidelines, including reduced dosing recommendations, for the use of abortive and preventative migraine medications in hepatic and renal failure.

Narrative review of peripheral nerve blocks for the management of headache.

OBJECTIVE: To provide an overview of the current available literature on peripheral nerve blocks for the management of migraine and other headache disorders in adults. BACKGROUND: Peripheral nerve blocks have been commonly performed in the headache practice for migraine, cluster headache, occipital neuralgia, and other headache disorders, despite a paucity of evidence supporting their use historically. In the past decade, there has been an effort to explore the efficacy and safety of peripheral nerve blocks for the management of headache, with the greatest interest centered around greater occipital blocks. DESIGN: We performed a search in PubMed using key words including "occipital nerve blocks," "peripheral nerve blocks," "occipital nerve," "migraine," "cluster headache," and "neuralgia." We reviewed the randomized controlled trials (RCTs), observational studies, and case series, and summarized the anatomy, techniques, and the evidence for the use of peripheral nerve blocks in different headache disorders, with particular focus on available RCTs. Case reports were included for a detail review of adverse events. RESULTS: Of 12 RCTs examining the use of greater occipital nerve blocks for migraine, all but one demonstrate efficacy with reduction in headache frequency, intensity, and/or duration compared to placebo. Studies have not demonstrated a difference in clinical outcomes with the use of corticosteroids for nerve blocks compared to blocks with local anesthetic in the treatment of migraine. There are two RCTs supporting the use of greater occipital blockade for cluster headache, both showing benefit of suboccipitally injected corticosteroid. One RCT suggests benefit of greater occipital nerve blocks for cervicogenic headache. Observational studies and case series/reports show that greater occipital nerve block may be effective in prolonged migraine aura, status migrainosus, post-dural puncture headache, and occipital neuralgia. Overall, peripheral nerve blocks are well tolerated. Serious side effects are rare but have been reported, including acute cerebellar syndrome and infection. CONCLUSIONS: Peripheral nerve blocks, especially occipital nerve blocks, are a viable treatment option for migraine and may be helpful in cluster headache as a transitional therapy or rescue therapy. Additional prospective studies are needed to investigate the efficacy and safety of occipital nerve blocks for long-term migraine prevention, as well as for other headache disorders, such as occipital neuralgia.

Real-World Patient Experience of CGRP-Targeting Therapy for Migraine: a Narrative Review.

PURPOSE OF REVIEW: To summarize available calcitonin gene-related peptide (CGRP)-targeting therapies for migraine and discuss their use in real-world populations. BACKGROUND: CGRP has long been a topic of interest in migraine pathophysiology, with new therapies targeting CGRP since 2018 for both the preventive and acute treatment of migraine. METHODS: We searched PubMed using keywords including "migraine," "CGRP," "real-world," "erenumab," "galcanezumab," "fremanezumab," "eptinezumab," "ubrogepant," "rimegepant," and "atogepant." We reviewed all pertinent studies and summarized main findings. We also compiled detailed patient characteristics (e.g., migraine diagnoses, medication overuse, prior treatment failures) and treatment outcome measures, such as 50% responder rates, reduction in migraine days, and adverse event rates in several tables. Overall, studies reporting real-world patient experiences of CGRP-targeting therapies suggested meaningful effectiveness for migraine treatment with response rates comparable to the numbers reported in clinical trials. Furthermore, studies suggested benefit in patients with multiple prior unsuccessful treatment trials, medication overuse, and complex medical comorbidities. In some studies, adverse event rates have been notably higher than reported in clinical trials. Additional long-term data is needed to further evaluate sustained efficacy, predictors of treatment response, and adverse events.

Two hundred and forty-eight cases of visual snow: A review of potential inciting events and contributing comorbidities.

OBJECTIVE: To review characteristics and outcomes of all cases of visual snow seen at our institution, with attention to possible triggering events or comorbidities. METHODS: This is a retrospective case series of patients seen at our tertiary care center from January 1994 to January 2020. Charts were reviewed if they contained the term "visual snow". RESULTS: Of the 449 charts reviewed, 248 patients described seeing visual snow in part or all of their vision. Thirty-eight reported transient visual snow as their typical migraine aura. Of the remaining 210 patients, 89 were reported to have either an inciting event or contributing comorbidity for their visual snow symptoms, including: Post-concussion (n = 15), dramatic change in migraine or aura (n = 14), post-infection (n = 13), hallucinogen persisting perception disorder (n = 10), ocular abnormalities (n = 7), idiopathic intracranial hypertension (n = 4), neoplastic (n = 1), and posterior cortical atrophy (n = 1). Some patients had partial improvement with benzodiazepines (n = 6), lamotrigine (n = 5), topiramate (n = 3) and acetazolamide (n = 3). Presenting characteristics were similar, but patients with visual snow attributed to an inciting event or contributing comorbidity were more likely to have some improvement in their symptoms by last follow-up compared to spontaneous visual snow (p < .001). CONCLUSIONS: Though most cases of visual snow are spontaneous, potential secondary causes should be recognized by clinicians. Patients who develop visual snow after an inciting event or related to an underlying comorbidity may have a better prognosis than those in whom it develops spontaneously. In select cases, treatment of the suspected underlying cause may significantly alleviate the otherwise typical intractable visual disturbances associated with visual snow.

Current Understanding of the Pathophysiology and Approach to Tension-Type Headache.

PURPOSE OF REVIEW: Description of headache dates back thousands of years, and to date, tension-type headache (TTH) remains the most common form of headache. We will review the history and current understanding of the pathophysiology of TTH and discuss the recommended clinical evaluation and management for this syndrome. RECENT FINDINGS: Despite being the most prevalent headache disorder, TTH pathophysiology remains poorly understood. Patients with TTH tend to have muscles that are harder, more tender to palpation, and may have more frequent trigger points of tenderness than patients without headache. However, cause and effect of these muscular findings are unclear. Studies support both peripheral and central mechanisms contributing to the pain of TTH. Diagnosis is based on clinical presentation, while the focus of evaluation is to rule out possible secondary causes of headache. Treatment options have remained similar over the course of the past decade, with some additional studies supportive of both pharmacological and non-pharmacological options. An approach to TTH has been outlined including historical context, evolution over time, and the best evidence regarding our current understanding of the complex pathophysiology and treatment of this disease.

First Bite Syndrome: What Neurologists Need to Know.

PURPOSE OF REVIEW: Though first bite syndrome is well known in surgical settings, it is not commonly included in the differential for sharp paroxysmal facial pain in the neurology literature. This paper will highlight the clinical features and relevant anatomy of first bite syndrome, with the goal of helping clinicians differentiate this from other similar facial pain disorders. RECENT FINDINGS: First bite syndrome is severe sharp or cramping pain in the parotid region occurring with the first bite of each meal and improving with subsequent bites. Pathophysiology has been attributed to imbalanced sympathetic/parasympathetic innervation of the parotid gland. This is seen most typically in the post-surgical setting following surgery in the parotid or parapharyngeal region, but neoplastic etiologies have also been reported. It is common for patients to present with concurrent great auricular neuropathy and/or Horner's syndrome. Evidence regarding treatment is limited to case reports/series, however, botulinum toxin injections and neuropathic medicines have been helpful in select cases. It is critical for clinicians to be able to differentiate first bite syndrome from other paroxysmal facial pain. To help with this, we have proposed diagnostic criteria for clinical assessment. Patients often improve gradually over time, but symptomatic treatment with botulinum toxin or neuropathic medicine may be required.

Great Auricular Neuralgia: Case Series.

BACKGROUND/OBJECTIVE: The great auricular nerve (GAN) arises from C2-C3 and provides innervation over the skin in the pre-auricular region, jaw angle, posteroinferior pinna, and mastoid. Although damage to the GAN has been reported following trauma or procedures nearby this nerve course, neuralgia of this nerve is uncommon with knowledge based on a handful of case reports in literature. The objective of this study is to describe the presentation, treatment, and outcome of 13 cases of GAN neuralgia. METHODS: Case series. Retrospecive review of charts from 1994 to 2018 with diagnoses: "auricular neuralgia," "auricular neuritis," or "auricular neuropathy." We included subjects with neuralgic pain within the distribution of the GAN, and excluded patients with atypical facial pain, GAN neuropathy, or unclear etiology. RESULTS: Of 79 charts, 13 patients met criteria (age at onset 11-59; 11 women, 2 men). Pain was most often described as paroxysmal stabbing provoked by: turning the head (n = 7), touching the neck (n = 5), neck position during sleep (n = 2), jaw movement (n = 2), and other (n = 2). Seven patients received GAN blocks: all noted dramatic improvement in pain, including 3 who continued to receive serial blocks at our institution successfully for the next 2 to 5 years. Two patients successfully transitioned from GAN blocks to GAN stimulators. One patient with GAN lymphoma had resolution of pain following GAN resection. CONCLUSION: GAN neuralgia should be considered in the differential for periauricular pain. GAN blocks or stimulators may be helpful for pain management.

COVID-19 and Headache Medicine: A Narrative Review of Non-Steroidal Anti-Inflammatory Drug (NSAID) and Corticosteroid Use.

OBJECTIVE: To summarize the current literature on non-steroidal anti-inflammatory drug and corticosteroid use during the coronavirus disease 2019 (COVID-19) pandemic, recognizing that these are commonly used treatments in the field of headache medicine. BACKGROUND: The use of non-steroidal anti-inflammatory drugs and corticosteroids in patients during the COVID-19 pandemic has been a controversial topic within the medical community and international and national health organizations. Lay press and social media outlets have circulated opinions on this topic despite the fact that the evidence for or against the use of these medications is sparse. In the field of headache medicine, these medications are used commonly and both patients and clinicians may have questions or hesitations pertaining to their use during the COVID-19 pandemic. METHODS: A detailed search of the scientific and popular literature was performed. RESULTS: There is limited literature pertaining to the safety of non-steroidal anti-inflammatory drugs and corticosteroids during the COVID-19 pandemic. To date, there are no clear scientific data that preclude the use of non-steroidal anti-inflammatory drugs in the general population who may acquire COVID-19 or in those acutely infected with the virus. Several health organizations have concluded that treatment with corticosteroids during active infection should be avoided due to concerns of prolonged viral shedding in the respiratory tract and the lack of survival benefit based on the data from past coronaviruses and influenza virus; specific exceptions exist including treatment for underlying asthma or chronic obstructive pulmonary disease, septic shock, and acute respiratory distress syndrome. CONCLUSION: Scientific information regarding the COVID-19 pandemic is constantly evolving, and limited or contradictory information can lead to confusion for both patients and clinicians. It is recommended that prior to prescribing non-steroidal anti-inflammatory drugs and steroids for the treatment of headache, clinicians have open discussions with their patients about the potential risks and benefits of using these medications during the COVID-19 pandemic. This manuscript summarizes the currently available evidence and understanding about these risks and benefits to help clinicians navigate such discussions.

Headache due to spontaneous spinal cerebrospinal fluid leak secondary to cerebrospinal fluid-venous fistula: Case series.

OBJECTIVE: Cerebrospinal fluid-venous fistula is an uncommon cause of spontaneous spinal cerebrospinal fluid leak (SSCSFL). We aim to describe the clinical presentation, imaging evaluation, treatment and outcome of SSCSFL secondary to cerebrospinal fluid-venous fistula. METHODS: A retrospective review was undertaken of SSCSFL cases secondary to cerebrospinal fluid-venous fistula confirmed radiologically or intraoperatively, seen at our institution from January 1994 to March 2019. Cases with undetermined SSCSFL etiology, alternative etiology or unconfirmed fistula were excluded. RESULTS: Forty-four of 156 patients met the inclusion criteria (31 women, 13 men). Mean age of symptom onset was 52.6 years (SD 8.7, range 33-71 years). Headache was the presenting symptom in almost all, typically daily (69%), and most often in occipital/suboccipital regions. Headache character was most commonly pressure (38%), followed by throbbing/pulsing (21.4%). Orthostatic headache worsening occurred in 69% and an even greater percentage of patients (88%) reported Valsalva-induced headache exacerbation or precipitation. Headache occurred in isolation to Valsalva maneuvers in 12%. Of 37 patients with documented cerebrospinal fluid opening pressure, 13% were <6 cmH2O; 84%, 7-20 cmH2O; and one, 25 cmH2O. Fistulas were almost exclusively thoracic (95.5%). Only one patient responded definitively to epidural blood patch (EBP). Forty-two patients underwent surgery. Most improved following surgery; 48.7% were completely headache free and 26.8% had at least 50% improvement. CONCLUSION: In our series, cerebrospinal fluid-venous fistula was associated with a greater occurrence of Valsalva-induced headache exacerbation or precipitation than orthostatic headache and did not respond to EBP. Surgery provided significant improvement. Cerebrospinal fluid-venous fistula should be considered early in the differential diagnosis of Valsalva-induced ("cough") headache.

Headache Attributed to Autonomic Dysreflexia: Clinical Presentation, Pathophysiology, and Treatment.

A patient presenting with marked elevation in blood pressure and concurrent headache often presents a diagnostic challenge for even the most seasoned clinician. When marked hypertension and headache occur in a patient with a history of upper spinal cord injury, the patient should be presumed to have autonomic dysreflexia until proven otherwise. Autonomic dysreflexia can at times trigger headaches, hypertension, and variations in pulse, as well other autonomic signs and symptoms. Autonomic dysreflexia is a medical emergency for which appropriate treatment may be life-saving. In this review, we address the historical origins, risk factors, pathophysiology, diagnostic criteria, clinical presentation, differential diagnosis, and treatment of headache attributed to autonomic dysreflexia. Included are two case presentations from the authors' clinic, which illustrate the diagnosis and treatment of headache attributed to autonomic dysreflexia.

The Effect of OnabotulinumtoxinA on Aura Frequency and Severity in Patients With Hemiplegic Migraine: Case Series of 11 Patients.

BACKGROUND: OnabotulinumtoxinA has been demonstrated to be effective for the preventive treatment of headache in individuals with chronic migraine and has been approved and recommended for this patient population. While the therapeutic effect of onabotulinumtoxinA on migraine headache is well documented, there is limited information on the effect of onabotulinumtoxinA on migraine aura. OBJECTIVE: Given the prolonged and often debilitating nature of aura in patients with hemiplegic migraine, our group sought to examine the effect of onabotulinumtoxinA on aura frequency and severity in this specific subset of migraine patients. METHODS: All clinical notes from July 1, 1994 to December 1, 2017 at our institution were retrospectively reviewed to identify patients diagnosed with hemiplegic migraine who received at least one set of onabotulinumtoxinA injections. Thirty-four patients were identified; and of those, 23 were excluded due to incomplete documentation regarding aura symptoms at follow-up visits. The clinical notes of the remaining 11 patients (4 with familial hemiplegic migraine [FHM] and 7 with sporadic hemiplegic migraine [SHM]) were reviewed, and the frequency and description of their headaches and aura before and after receiving onabotulinumtoxinA were recorded. RESULTS: Nine of the 11 patients in our series noted a decrease in the frequency, severity, and/or duration of their aura after receiving onabotulinumtoxinA. Of the 2 non-responders, one was FHM and one was SHM. Of the 9 that noticed improved aura symptoms, 6 described a "wearing off" effect of onabotulinumtoxinA around week 9 or 10 of the 12-week cycle, with subsequent improvement after the next round. CONCLUSION: For 9 of 11 patients with hemiplegic migraine, onabotulinumtoxinA was helpful not only in reducing the frequency and severity of headaches but also in reducing the frequency and severity of the aura. In this manuscript, we speculate on potential pathophysiologic mechanisms that could have contributed to this effect.

Visual Snow Syndrome: Proposed Criteria, Clinical Implications, and Pathophysiology.

PURPOSE OF REVIEW: In this article, we review illustrative case descriptions of both primary and secondary visual snow from our clinic. We discuss recently proposed criteria for visual snow syndrome and offer a slight modification of these criteria. We also discuss the theories on the pathophysiological mechanisms of visual snow, as well as the current approach to treatment. RECENT FINDINGS: Visual snow is a condition where patients see constant, innumerable flickering dots throughout the visual field, similar to "TV static." Though visual snow was originally described in 1995, there were still fewer than 10 cases in the literature prior to 2014. In the last 4 years, this has grown to approximately 200 cases and there has been a concentrated effort to better understand and characterize this condition. It has become apparent that patients who see visual snow frequently have additional visual and non-visual symptoms, and the consistency of these symptoms has led to proposed criteria for visual snow syndrome. When seeing a patient with visual snow, it is important to rule out a possible underlying secondary etiology. Patients with visual snow syndrome frequently have comorbid migraine, but visual snow appears to be a separate entity from persistent migraine aura. The pathophysiology of this syndrome is not clear, but recent neurophysiologic and neuroimaging studies have helped advance our understanding.

Procedural Headache Medicine in Neurology Residency Training: A Survey of US Program Directors.

OBJECTIVE: To survey neurology residency program directors (PDs) on trainee exposure, supervision, and credentialing in procedures widely utilized in headache medicine. BACKGROUND: Clinic-based procedures have assumed a prominent role in headache therapy. Headache fellows obtain procedural competence, but reliance on fellowship-trained neurologists cannot match the population eligible for treatments. The inclusion of educational modules and mechanisms for credentialing trainees pursuing procedural competence in residency curricula at individual programs is not known. METHODS: A web-based survey of US neurology residency PDs was designed by the American Headache Society (AHS) procedural special interest section in collaboration with AHS and American Academy of Neurology's Headache and Facial Pain section leadership. The survey addressed exposure, training, and credentialing in: (1) onabotulinumtoxinA (onabotA) injections, (2) extracranial peripheral nerve blocks (PNBs), and (3) trigger point injections (TPIs). RESULTS: Fifty-five PDs (42.6%) completed the survey. Compared to noncompleters, survey completers were more likely to feature headache fellowships at their institutions (38.2% vs 10.8%, P=0.0002). High exposure (onabotA=90.9%, PNBs=80.0%, TPIs=70.9%) usually featured hands-on patient instruction (66.2%) and lectures (55.7%). Supervised performance rates were high (onabotA=65.5%, PNBs=60.0%, TPIs=52.7%), usually in continuity clinic (60.0%) or headache elective (50.9%). Headache specialists (69.1%) or general neurology (32.7%) faculty most commonly trained residents. Formal credentialing was uncommon (16.4-18.2%), mostly by documenting supervised procedures (25.5%). Only 27.3% of programs permitted trainees to perform procedures independently. Most PDs felt procedural exposure (80.0-90.9%) and competence (50.9-56.4%) by all trainees was important. CONCLUSIONS: Resident exposure to procedures for headache is high, but credentialing mechanisms, while desired by most PDs, are not generally in place. Implementation of a credentialing process may ensure trainees enter practice with the ability to perform procedures safely and effectively.

The Sphenopalatine Ganglion: Anatomy, Pathophysiology, and Therapeutic Targeting in Headache.

The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino-autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures.

No Laughing Matter: Gelastic Migraine and Other Unusual Headache Syndromes.

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