Hypothalamic involvement and activation in cluster headache

Psilocybin pulse regimen reduces cluster headache attack frequency in the blinded extension phase of a randomized controlled trial

BACKGROUND

In a recent randomized, double-blind, placebo-controlled study, we observed a nonsignificant reduction of attack frequency in cluster headache after pulse administration of psilocybin (10 mg/70 kg, 3 doses, 5 days apart each). We carried out a blinded extension phase to consider the safety and efficacy of repeating the pulse regimen.

METHODS

Eligible participants returned to receive a psilocybin pulse at least 6 months after their first round of study participation. Participants kept headache diaries starting two weeks before and continuing through eight weeks after the first drug session. Ten participants completed the extension phase and all ten were included in the final analysis.

RESULTS

In the three weeks after the start of the pulse, cluster attack frequency was significantly reduced from baseline (18.4 [95% confidence interval 8.4 to 28.4] to 9.8 [4.3 to 15.2] attacks/week; p = 0.013, d' = 0.97). A reduction of approximately 50% was seen regardless of individual response to psilocybin in the first round. Psilocybin was well-tolerated without any unexpected or serious adverse events.

DISCUSSION

This study shows a significant reduction in cluster attack frequency in a repeat round of pulse psilocybin administration and suggests that prior response may not predict the effect of repeated treatment. To gauge the full potential of psilocybin as a viable medicine in cluster headache, future work should investigate the safety and therapeutic efficacy in larger, more representative samples over a longer time period, including repeating the treatment.

CLINICAL TRIALS REGISTRATION

NCT02981173.

Regulation of headache response and transcriptomic network by the trigeminal ganglion clock

OBJECTIVE

To characterize the circadian features of the trigeminal ganglion in a mouse model of headache.

BACKGROUND

Several headache disorders, such as migraine and cluster headache, are known to exhibit distinct circadian rhythms of attacks. The circadian basis for these rhythmic pain responses, however, remains poorly understood.

METHODS

We examined trigeminal ganglion ex vivo and single-cell cultures from Per2::LucSV reporter mice and performed immunohistochemistry. Circadian behavior and transcriptomics were investigated using a novel combination of trigeminovascular and circadian models: a nitroglycerin mouse headache model with mechanical thresholds measured every 6 h, and trigeminal ganglion RNA sequencing measured every 4 h for 24 h. Finally, we performed pharmacogenomic analysis of gene targets for migraine, cluster headache, and trigeminal neuralgia treatments as well as trigeminal ganglion neuropeptides; this information was cross-referenced with our cycling genes from RNA sequencing data to identify potential targets for chronotherapy.

RESULTS

The trigeminal ganglion demonstrates strong circadian rhythms in both ex vivo and single-cell cultures, with core circadian proteins found in both neuronal and non-neuronal cells. Using our novel behavioral model, we showed that nitroglycerin-treated mice display circadian rhythms of pain sensitivity which were abolished in arrhythmic Per1/2 double knockout mice. Furthermore, RNA-sequencing analysis of the trigeminal ganglion revealed 466 genes that displayed circadian oscillations in the control group, including core clock genes and clock-regulated pain neurotransmitters. In the nitroglycerin group, we observed a profound circadian reprogramming of gene expression, as 331 of circadian genes in the control group lost rhythm and another 584 genes gained rhythm. Finally, pharmacogenetics analysis identified 10 genes in our trigeminal ganglion circadian transcriptome that encode target proteins of current medications used to treat migraine, cluster headache, or trigeminal neuralgia.

CONCLUSION

Our study unveiled robust circadian rhythms in the trigeminal ganglion at the behavioral, transcriptomic, and pharmacogenetic levels. These results support a fundamental role of the clock in pain pathophysiology.

PLAIN LANGUAGE SUMMARY

Several headache diseases, such as migraine and cluster headache, have headaches that occur at the same time each day. We learned that the trigeminal ganglion, an important pain structure in several headache diseases, has a 24-hour cycle that might be related to this daily cycle of headaches. Our genetic analysis suggests that some medications may be more effective in treating migraine and cluster headache when taken at specific times of the day.

Case report: Recurrent nocturnal awakenings in cluster headache: a different type of ghost attack

Introduction

Cluster headache (CH) is a trigeminal autonomic cephalalgia characterized by attacks of severe unilateral pain associated with ipsilateral autonomic symptoms. Cluster headache attacks exhibit nocturnal predilection, and sleep disorders could be the first manifestation of an incipient cluster period. Sleep alterations in cluster headache patients may reflect the pivotal role of the hypothalamus, which is crucially involved in the pathophysiology of this primary headache. We describe the case of a patient affected by episodic cluster headache who experienced a sleep disorder after starting therapy with verapamil.

Case presentation

A 47-year-old man was affected by episodic cluster headache, characterized by attacks of excruciating pain in the left orbital and temporal regions, associated with prominent ipsilateral vegetative symptoms. Headaches occurred during the night, with one or two nocturnal attacks appearing at 11.30-12 p.m. and 4-4.30 a.m. Preventive treatment with verapamil was started, with immediate pain relief. Later, he experienced consecutive nocturnal awakenings for a couple of weeks, always at the same time, without any pain or autonomic symptoms. He was not agitated and did not need to get out of bed; after the awakenings, he reported sleep disturbances with vivid dreams.

Discussion and conclusion

This case represents the first description of recurrent cyclic nocturnal awakenings, without pain and autonomic symptoms, in a patient with episodic cluster headache during the active phase of a cluster bout. Nocturnal awakenings, started after the introduction of effective preventive therapy, might be an unusual form of "ghost attacks." After the beginning of prophylactic therapy, patients often describe mild pain or localized pressure in the same localization of CH attack. Similarly, the appearance of sleep disturbances, without any pain or vegetative symptoms, should be regarded as a warning sign of a still active cluster bout. Since these manifestations may influence therapeutic management, they should be carefully investigated.

Adapting psychedelic medicine for headache and chronic pain disorders

INTRODUCTION

While the majority of current research and development surrounds depression, demoralization, and substance use disorders, there are numerous reports of psychedelics having beneficial effects in other branches of medicine, including for headache disorders and chronic pain.

AREAS COVERED

This perspective reviews conventional forms of treatment for headache and other chronic pain disorders and describes historical, recent, and ongoing investigations of the therapeutic effects of psychedelics in these disorders. The first two clinical trials of psilocybin in headache disorders and recent case reports of psilocybin mushroom self-administration in chronic pain patients are described. This perspective highlights several factors related to the application of psychedelics in chronic pain disorders, comparing this with the standard psychedelic-assisted psychotherapy model of treatment.

EXPERT OPINION

When faced with a more constricted view of psychedelic medicine that features larger doses, underscores subjective effects in the mediation of therapeutic outcomes, and requires adjunctive psychotherapy to ensure safety and efficacy, the application of psychedelics in headache and chronic pain disorders may face challenges. It will be important to allow for flexibility and adaptation in protocols to evaluate different treatment paradigms, mechanisms of action, and the range of pharmacologic and extra-pharmacologic factors that affect psychedelic treatment outcomes.

Exploratory investigation of a patient-informed low-dose psilocybin pulse regimen in the suppression of cluster headache: Results from a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Using a patient-informed regimen, we conducted an exploratory randomized, double-blind, placebo-controlled study to systematically investigate the effects of psilocybin in cluster headache.

BACKGROUND

Sustained reductions in cluster headache burden after limited quantities of psilocybin-containing mushrooms are anecdotally reported, although to date there are no controlled studies investigating these effects.

METHODS

Participants were randomized to receive psilocybin (0.143 mg/kg) or placebo (microcrystalline cellulose) in a pulse of three doses, each ~5 days apart. Participants maintained headache diaries starting 2 weeks before and continuing through 8 weeks after the first drug session. A total of 16 participants were randomized to receive experimental drug and 14 were included in the final analysis.

RESULTS

In the 3 weeks after the start of the pulse regimen, the change in cluster attack frequency was 0.03 (95% confidence interval [CI] -2.6 to 2.6) attacks/week with placebo (baseline 8.9 [95% CI 3.8 to 14.0]) and -3.2 (95% CI -8.3 to 1.9) attacks/week with psilocybin (baseline 9.6 [95% CI 5.6 to 13.6]; p = 0.251). Group difference in change from baseline had a moderate effect size (d = 0.69). The effect size was small in episodic participants (d = 0.35) but large in chronic participants (d = 1.25), which remained over the entire 8-week period measured (d = 0.81). Changes in cluster attack frequency were not correlated with the intensity of acute psychotropic effects during psilocybin administration. Psilocybin was well-tolerated without any unexpected or serious adverse events.

CONCLUSIONS

Findings from this initial, exploratory study provide valuable information for the development of larger, more definitive studies. Efficacy outcomes were negative, owing in part to the small number of participants. The separation of acute psychotropic effects and lasting therapeutic effects underscores the need for further investigation into the mechanism(s) of action of psilocybin in headache disorders.

Brain regions involved in fractional amplitude of low-frequency fluctuation in cluster headache patients: a resting-state functional MRI study

BACKGROUND

We used resting-state functional magnetic resonance imaging (RS-fMRI) to assess the possible pathogenic role of fALFF in CH. A limited number of studies have reported on fractional amplitude of low-frequency fluctuation (fALFF) in cluster headache (CH).

METHODS

RS-fMRI scans of 23 patients with CH were obtained (11with left-sided headache and 12 with right-sided headache), along with scans of 23 age- and sex-matched normal controls. The RS-fMRI data were analyzed to explore abnormal brain activity in the left CH and right CH patients during the non-painful state in one cluster period. fALFF was compared between patients and controls, and correlation analysis between the regional mean fALFF values and clinical characteristics was performed.

RESULTS

A decrease in fALFF was detected in the left cerebellum, left lentiform nucleus, left frontal lobe, left anterior cingulate, and right postcentral gyrus in the left CH group compared to the controls, while a decrease of fALFF was detected in the right cerebellum, right cingulate gyrus, right superior parietal lobule, right inferior parietal lobule, right postcentral gyrus, and left precuneus in the right CH group. No patient had a region with increased fALFF. A moderate correlation was observed between some regional mean fALFF values and the clinical characteristics.

CONCLUSIONS

We deduced that dysfunction in multiple brain areas is involved in the non-painful state of CH during a cluster period.

Sex-related differences in cluster headache: A hospital-based study in Taiwan

OBJECTIVES

To compare the clinical profiles between male and female cluster headache patients from a large cohort.

METHODS

This hospital-based study enrolled patients diagnosed with cluster headache between 1997 to 2021. Participants completed structured questionnaires collecting information on demographics, clinical profiles, and quality of life. Treatment regimens and effectiveness were determined through medical chart review. All variables were compared between the sexes.

RESULTS

In total, 798 patients (M/F:659/139) were enrolled. The male-to-female ratio was 4.7:1 for the full study period, but it declined from 5.2:1 to 4.3:1 for patients enrolled before and after 2010, respectively. The frequencies of chronic cluster headache (M:1.2%, F:1.4%) and aura (M:0.3%, F:0.7%) were low but similar between the sexes. Most headache features showed no difference between men and women. Female patients had significantly longer attack duration, shorter inter-bout duration, higher frequencies for eyelid edema, nausea and vomiting and lower frequencies for conjunctival injection and pacing. Sex difference did not influence headache-associated disability, anxiety, or depression, but poor sleep quality was significantly more common in women. Among menstruating women, 22/122 (18.0%) reported worsening headaches during menses. The effectiveness of treatment was similar between the sexes.

CONCLUSIONS

Despite a decline of male-to-female ratio in the past two decades, most clinical profiles were similar between the sexes.

Circadian rhythmicity on red ear syndrome in a patient with migraine: A case report

BACKGROUND

Red ear syndrome (RES) was first described by Lance in 1994. It is characterized by recurrent attacks of redness of the ear, accompanied by burning pain, increased temperature, dysesthesia, and nosological relationship with headache.

CASE

We report the case of a 43-year-old woman with migraine who developed RES. Redness episodes occurred at the same time of the day. She had a good therapeutic response to gabapentin.

CONCLUSIONS

To the best of our knowledge, this is the first case of RES in which redness episodes occurred at the same time of the day.

Noninvasive Neuromodulation in Headache: An Update

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.

Alterations of the structural covariance network in the hypothalamus of patients with cluster headache

OBJECTIVE

The hypothalamus is one of the key structures involved in the pathophysiology of cluster headaches. This study aimed to analyze the volume of hypothalamic subunits and structural covariance networks in the hypothalamus of patients with cluster headache.

METHODS

We retrospectively enrolled 18 patients with episodic cluster headache and 18 age- and sex-matched healthy controls. We calculated individual structural volumes in ten hypothalamic subunits using three-dimensional T1-weighted imaging and the FreeSurfer program, which conducted an automated segmentation based on deep convolutional neural networks. We also performed an analysis of the structural covariance network in the hypothalamus using graph theory and the BRAPH program. We compared the volumes of hypothalamic subunits and structural covariance networks in the hypothalamus of patients with cluster headache versus those of healthy controls.

RESULTS

There were no significant differences in the structural volumes of the whole hypothalamus and hypothalamic subunits between patients with cluster headache and healthy controls. However, patients with cluster headache had significant alterations of the structural covariance network in the hypothalamus compared to that of healthy controls. The network measure of small-worldness index in patients with cluster headache was lower than that in healthy controls (0.844 vs. 0.955, p = 0.004).

CONCLUSION

We demonstrated a significant difference in the structural covariance network in the hypothalamus of patients with cluster headache versus those of healthy controls. These findings could be related to the pathogenesis of cluster headache.

New insights in post-traumatic headache with cluster headache phenotype: a cohort study

OBJECTIVES

To define the characteristics of post-traumatic headache with cluster headache phenotype (PTH-CH) and to compare these characteristics with primary CH.

METHODS

A retrospective study was conducted of patients seen between 2007 and 2017 in a headache centre and diagnosed with PTH-CH that developed within 7 days of head trauma. A control cohort included 553 patients with primary CH without any history of trauma who attended the headache clinic during the same period. Data including demographics, attack characteristics and response to treatments were recorded.

RESULTS

Twenty-six patients with PTH-CH were identified. Multivariate analysis revealed significant associations between PTH-CH and family history of CH (OR 3.32, 95% CI 1.31 to 8.63), chronic form (OR 3.29, 95% CI 1.70 to 6.49), parietal (OR 14.82, 95% CI 6.32 to 37.39) or temporal (OR 2.04, 95% CI 1.10 to 3.84) location of pain, and presence of prominent cranial autonomic features during attacks (miosis OR 11.24, 95% CI 3.21 to 41.34; eyelid oedema OR 5.79, 95% CI 2.57 to 13.82; rhinorrhoea OR 2.65, 95% CI 1.26 to 5.86; facial sweating OR 2.53, 95% CI 1.33 to 4.93). Patients with PTH-CH were at a higher risk of being intractable to acute (OR 12.34, 95% CI 2.51 to 64.73) and preventive (OR 16.98, 95% CI 6.88 to 45.52) treatments and of suffering from associated chronic migraine (OR 10.35, 95% CI 3.96 to 28.82).

CONCLUSION

This largest series of PTH-CH defines it as a unique entity with specific evolutive profile. Patients with PTH-CH are more likely to suffer from the chronic variant, have marked autonomic features, be intractable to treatment and have associated chronic migraine compared with primary CH.

Pharmacotherapy for Cluster Headache

Cluster headache is characterised by attacks of excruciating unilateral headache or facial pain lasting 15 min to 3 h and is seen as one of the most intense forms of pain. Cluster headache attacks are accompanied by ipsilateral autonomic symptoms such as ptosis, miosis, redness or flushing of the face, nasal congestion, rhinorrhoea, peri-orbital swelling and/or restlessness or agitation. Cluster headache treatment entails fast-acting abortive treatment, transitional treatment and preventive treatment. The primary goal of prophylactic and transitional treatment is to achieve attack freedom, although this is not always possible. Subcutaneous sumatriptan and high-flow oxygen are the most proven abortive treatments for cluster headache attacks, but other treatment options such as intranasal triptans may be effective. Verapamil and lithium are the preventive drugs of first choice and the most widely used in first-line preventive treatment. Given its possible cardiac side effects, electrocardiogram (ECG) is recommended before treating with verapamil. Liver and kidney functioning should be evaluated before and during treatment with lithium. If verapamil and lithium are ineffective, contraindicated or discontinued because of side effects, the second choice is topiramate. If all these drugs fail, other options with lower levels of evidence are available (e.g. melatonin, clomiphene, dihydroergotamine, pizotifen). However, since the evidence level is low, we also recommend considering one of several neuromodulatory options in patients with refractory chronic cluster headache. A new addition to the preventive treatment options in episodic cluster headache is galcanezumab, although the long-term effects remain unknown. Since effective preventive treatment can take several weeks to titrate, transitional treatment can be of great importance in the treatment of cluster headache. At present, greater occipital nerve injection is the most proven transitional treatment. Other options are high-dose prednisone or frovatriptan.

Alterations of structural connectivity in episodic cluster headache: A graph theoretical analysis

We evaluated structural volumes and connectivity using graph theoretical analysis in patients with cluster headache. Ten patients with episodic cluster headache were recruited, who had a normal brain MRI on visual inspection. We also enrolled a control group of 20 healthy volunteers. All of the participants underwent 3-D volumetric T1-weighted imaging. We obtained the structural volumes using FreeSurfer image analysis and performed structural global and local connectivity analysis using BRAPH. The volumes of the left caudal anterior cingulate and postcentral gyrus were decreased in the patients with cluster headache compared to healthy individuals. In addition, in the measures of local structural connectivity, there was significant hub re-organization in the patients with cluster headache; the strength of the right frontopolar, left pericalcarine, and left posterior cingulate gyrus, the betweenness centrality of the right precentral and left pericalcarine gyrus, and the closeness centrality of the left pericalcarine and left posterior cingulate gyrus were decreased. Whereas the betweenness centrality of the right rostral middle frontal and left inferior temporal gyrus were increased in the patients with cluster headache. However, the measures of global structural connectivity were not different between the patients with cluster headache and healthy individuals. We demonstrate that the structural volumes and connectivity in patients with cluster headache are significantly different from those in healthy controls, especially revealing hub re-organization. These alterations are implicated in the pathogenesis of cluster headache and suggest that cluster headache is a network disease.

Location and Volume of MRI Artifacts in Patients With Implanted Sphenopalatine Ganglion Neurostimulators for Treatment of Chronic Cluster Headache

INTRODUCTION

Sphenopalatine ganglion stimulation (SPG-S) is an invasive form of neuromodulation by which a neurostimulator is implanted into the pterygopalatine fossa to treat refractory chronic cluster headache. The implant is MRI conditional, up to 3 T, however there is no clinical data on the shape, size, and location of the artifact produced by the implant.

MATERIALS AND METHODS

Records of patients with SPG-S were analyzed for postoperative cranial MRI scans. MRI and intraoperative CT scans for visualization of the implant were fused and volumetry was performed for both the implant and the MRI artifact in different MRI sequences.

RESULTS

In total, n = 3 patients with postoperative MRI scans were identified. The mean CT artifact volume was 0.73 cm³ (±0.15 cm³ ). MRI artifact volume differed between sequences (range: 25.2-220.7 cm³ ). The intracranial space was largely unaffected besides the pole of the ipsilateral temporal lobe and the basal frontal gyrus. MRI artifacts affected the extracranial space (orbit, maxillary and ethmoid sinuses, and parts of the parotid gland). No adverse events occurred during or after MRI scans.

CONCLUSIONS

Cranial MRI scans with SPG-S implants were safely performed in three patients following the manufacturer's MRI conditions. MRI artifacts were mostly located in the extracranial space. Brain MRI imaging is largely unaffected.

CONFLICT OF INTEREST

The authors declare no potential conflicts of interest with respect to research, authorship, and/or publication of this article.

A new era in headache treatment

Primary headache disorders, such as migraine and cluster headache, are common and often debilitating. When preventive therapy is needed, several oral medications are used. Patients tend to have poor adherence and persistence on their preventive therapy. The introduction of treatments blocking calcitonin gene-related peptide (CGRP) is anticipated to begin a new era in migraine preventive treatment. In addition, non-triptan serotonin receptor agonists, newer delivery systems for older therapies, and innovative devices represent other exciting advances in acute and preventive migraine and cluster treatment and shall also be discussed in this review.

Neuroendocrine Associations Underlying the Persistent Therapeutic Effects of Classic Serotonergic Psychedelics

Recent reports on the effects of psychedelic-assisted therapies for mood disorders and addiction, as well as the effects of psychedelics in the treatment of cluster headache, have demonstrated promising therapeutic results. In addition, the beneficial effects appear to persist well after limited exposure to the drugs, making them particularly appealing as treatments for chronic neuropsychiatric and headache disorders. Understanding the basis of the long-lasting effects, however, will be critical for the continued use and development of this drug class. Several mechanisms, including biological and psychological ones, have been suggested to explain the long-lasting effects of psychedelics. Actions on the neuroendocrine system are some such mechanisms that warrant further investigation in the study of persisting psychedelic effects. In this report, we review certain structural and functional neuroendocrinological pathologies associated with neuropsychiatric disorders and cluster headache. We then review the effects that psychedelic drugs have on those systems and provide preliminary support for potential long-term effects. The circadian biology of cluster headache is of particular relevance in this area. We also discuss methodologic considerations for future investigations of neuroendocrine system involvement in the therapeutic benefits of psychedelic drugs.

Macro- and microstructural alterations of the subcortical structures in episodic cluster headache

Background Previous functional and structural imaging studies have revealed that subcortical structures play a key a role in pain processing. The recurring painful episodes might trigger maladaptive plasticity or alternatively degenerative processes that might be detected by MRI as changes in size or microstructure. In the current investigation, we aimed to identify the macro- and microstructural alterations of the subcortical structures in episodic cluster headache. Methods High-resolution T1-weighted and diffusion-weighted MRI images with 60 gradient directions were acquired from 22 patients with cluster headache and 94 healthy controls. Surface-based segmentation analysis was used to measure the volume of the subcortical nuclei, and mean diffusion parameters (fractional anisotropy, mean, radial and axial diffusivity) were determined for these structures. In order to understand whether the size and diffusion parameters could be investigated in a headache lateralised manner, first the asymmetry of the size and diffusion parameters of the subcortical structures was analysed. Volumes and diffusion parameters were compared between groups and correlated with the cumulative number of headache days. To account for the different size of the patient and control group, a bootstrap approach was used to investigate the stability of the findings. Results A significant lateralisation of the size (caudate, putamen and thalamus) and the diffusion parameters of the subcortical structures were found in normal controls. In cluster headache patients, the mean fractional anisotropy of the right amygdalae, the mean axial and mean diffusivity of the right caudate nucleus and the radial diffusivity of the right pallidum were higher. The mean anisotropy of the right pallidum was lower in patients. Conclusion The analysis of the pathology in the subcortical structures in episodic cluster headache reveals important features of the disease, which might allow a deeper insight into the pathomechanism of the pain processing in this headache condition.

A Report of Cranial Autonomic Symptoms in Migraineurs

The presence of cranial autonomic symptoms in migraine is well known and thought to represent activation of the trigeminal parasympathetic reflex pathway similar to trigeminal autonomic cephalalgias. However, studies regarding the prevalence of these symptoms are few. The characteristics of migraineurs with cranial autonomic symptoms and the association of cranial autonomic symptoms with laterality of headache have never been studied in a clinic population. Seventy-eight consecutive subjects with migraine were recruited from the Headache Clinic of the Department of Psychiatry after exclusion of subjects with secondary headache. Their demographic data and detailed history of headache were noted and leading questions were asked regarding cranial autonomic symptoms. χ2 test and Fisher's exact test was used for categorical variables, whereas an independent sample t-test was applied on numerical data. Spearman's correlation was used for correlational analysis of categorical variables. Female subjects (78.2%) outnumbered males and the average duration of illness in the whole sample was 3.81 years. Migraine without aura (53.8%) was the commonest diagnosis, followed by migraine with aura (24.4%). Cranial autonomic symptoms were present in 73.1% of subjects and, commonly, they were ipsilateral to headache. Moreover, strictly unilateral cranial autonomic symptoms were reported by only 32% of patients. The anatomical side of headache did not affect the presence of autonomic symptoms. Those with or without autonomic symptoms did not differ with respect to gender, diagnosis, laterality of headache or associated symptoms except phonophobia, which was more common in subjects with autonomic symptoms ( P = 0.05). Those with autonomic symptoms had longer duration of illness ( P = 0.03) and longer headache episodes ( P = 0.04). In addition, sleep was ineffective in relieving their headache ( P = 0.02). Cranial autonomic symptoms are frequent in migraineurs and are common in subjects with long duration of illness and longer headache episodes. Clinical evidence in the present study suggests that subjects with cranial autonomic symptoms have a hyperactive efferent arm of trigeminal autonomic reflex. The connections of trigeminal nucleus with the locus coeruleus and dorsal raphe nucleus may account for the observed phenotypic differences between the two groups. Further research, however, is required to elucidate the underlying neural mechanisms of cranial autonomic symptoms in migraine.

Comprehensive Review of Medicinal Marijuana, Cannabinoids, and Therapeutic Implications in Medicine and Headache: What a Long Strange Trip It's Been …

BACKGROUND

The use of cannabis, or marijuana, for medicinal purposes is deeply rooted though history, dating back to ancient times. It once held a prominent position in the history of medicine, recommended by many eminent physicians for numerous diseases, particularly headache and migraine. Through the decades, this plant has taken a fascinating journey from a legal and frequently prescribed status to illegal, driven by political and social factors rather than by science. However, with an abundance of growing support for its multitude of medicinal uses, the misguided stigma of cannabis is fading, and there has been a dramatic push for legalizing medicinal cannabis and research. Almost half of the United States has now legalized medicinal cannabis, several states have legalized recreational use, and others have legalized cannabidiol-only use, which is one of many therapeutic cannabinoids extracted from cannabis. Physicians need to be educated on the history, pharmacology, clinical indications, and proper clinical use of cannabis, as patients will inevitably inquire about it for many diseases, including chronic pain and headache disorders for which there is some intriguing supportive evidence.

OBJECTIVE

To review the history of medicinal cannabis use, discuss the pharmacology and physiology of the endocannabinoid system and cannabis-derived cannabinoids, perform a comprehensive literature review of the clinical uses of medicinal cannabis and cannabinoids with a focus on migraine and other headache disorders, and outline general clinical practice guidelines.

CONCLUSION

The literature suggests that the medicinal use of cannabis may have a therapeutic role for a multitude of diseases, particularly chronic pain disorders including headache. Supporting literature suggests a role for medicinal cannabis and cannabinoids in several types of headache disorders including migraine and cluster headache, although it is primarily limited to case based, anecdotal, or laboratory-based scientific research. Cannabis contains an extensive number of pharmacological and biochemical compounds, of which only a minority are understood, so many potential therapeutic uses likely remain undiscovered. Cannabinoids appear to modulate and interact at many pathways inherent to migraine, triptan mechanisms ofaction, and opiate pathways, suggesting potential synergistic or similar benefits. Modulation of the endocannabinoid system through agonism or antagonism of its receptors, targeting its metabolic pathways, or combining cannabinoids with other analgesics for synergistic effects, may provide the foundation for many new classes of medications. Despite the limited evidence and research suggesting a role for cannabis and cannabinoids in some headache disorders, randomized clinical trials are lacking and necessary for confirmation and further evaluation.

Concomitant occurrence of different trigeminal autonomic cephalalgias: A case series and review of the literature

Introduction

The trigeminal autonomic cephalalgias (TACs) subsume four primary headache disorders. Hemicrania continua is increasingly regarded as an additional TAC. In rare cases patients may present with two different TACs or a TAC and hemicrania continua.

Cases

We report four patients with two different TACs or one TAC and hemicrania continua. Two patients presented with cluster headache and paroxysmal hemicrania, one patient with cluster headache and hemicrania continua, and one patient suffered from cluster headache and SUNCT.

Discussion

While the International Classification of Headache Disorders (ICHD-II) proposes specific diagnostic criteria, the variability of clinical presentation may make clear diagnosis difficult. All patients fulfilled the ICHD-II criteria. The manifestation of two different TACs or hemicrania continua in one patient is uncommon but possible and should be taken into account especially when chronic headache patients present with changing headache symptoms.

Selective decreased grey matter volume of the pain-matrix network in cluster headache

AIM

We assessed the pattern of regional white matter and grey matter abnormalities in patients with cluster headache (CH), using tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM).

METHODS

Using a 3.0 Tesla scanner, dual-echo, diffusion tensor and 3D T1-weighted scan were acquired from 15 patients with episodic CH and 19 healthy controls. TBSS analysis was performed using the FMRIB's Diffusion Toolbox. VBM was performed on the 3D T1-weighted images using SPM8.

RESULTS

No diffusivity and volumetry abnormalities of brain white matter were detected in CH patients. Compared with controls, CH patients showed decreased grey matter volume in the right thalamus, head of the right caudate nucleus, right precentral gyrus, right posterior cingulate cortex, bilateral middle frontal gyrus, right middle temporal gyrus, left inferior parietal lobule and left insula (p < 0.001). They also had increased grey matter volume of the right cuneus. The results did not change after hemisphere mirroring in the five patients with left lateralized attacks. The decreased left middle frontal gyrus volume was significantly correlated with disease duration (r = -0.79, p < 0.001).

CONCLUSION

CH patients experience tissue abnormalities of grey matter regions that are part of the antinociceptive system, which is shared with other chronic pain conditions.

Dynamic mechanical (brush) allodynia in cluster headache: a prevalence study in a tertiary headache clinic

Cutaneous allodynia (CA) has been described in migraine and has been related to treatment failure. There are little data about the incidence of CA in other primary headache syndromes such as cluster headache (CH). The objectives of this study are to evaluate the prevalence of dynamic mechanical (brush) allodynia (BA) in CH patients attending a tertiary headache clinic, and to assess its relation to disease characteristics. Adult patients with episodic or chronic CH were recruited. We obtained demographic data and data on disease characteristics through a structured questionnaire, and tested the patients for brush allodynia BA by applying a 4 x 4 gauze pad over the V1, C2/C3 and C8 skin areas bilaterally. The prevalence of allodynia in the entire study population and in the different sub-groups was calculated. We also examined the association between CA and demographic parameters, and its association with disease characteristics. Forty-one patients were recruited (22 men, 19 women; mean age 44.9 years). Twenty-two had chronic CH (CCH) and 19 had episodic CH (ECH). Mean disease duration was 14.1 years (12.3 the CCH group and 15.7 in the ECH group). Overall, 20 (49%) patients were allodynic. There was no statistically significant association between the presence of allodynia and age, gender, diagnosis (episodic vs. chronic CH), disease duration or disease severity. In conclusion, BA was common in this CH patient sample. The therapeutic implications of the presence of BA in CH need to be further studied.

Sinus headaches: avoiding over- and mis-diagnosis

'Sinus headache' is a term used by many patients and primary-care physicians and, contrary to popular belief, sinus headaches are uncommon. Headaches that are due to sinusitis are confined to a minority of patients who have acute frontal sinusitis or sphenoiditis. The International Headache Society classification is robust in qualifying the term sinus headache and says that "chronic sinusitis is not validated as a cause of headache and facial pain unless relapsing into an acute stage". The vast majority of people who present with a symmetrical frontal or temporal headache, sometimes with an occipital component, have tension-type headache. Unilateral, episodic headaches are often vascular in origin. The idea that sinusitis can trigger migraine is misplaced, as the whole symptom complex is vascular and coexisting nasal congestion is due to vasodilation of the nasal mucosa that is sometimes part of the vascular event. The use of nasal endoscopy and imaging of the paranasal sinuses have advanced our appreciation that these patients are suffering from a vascular event. When these patients are asked to attend a clinic when they are symptomatic, the vast majority are found not to have a sinus infection. Sinusitis rarely causes headache, let alone facial pain, except when there is an acute bacterial infection when the sinus in question cannot drain, and it is usually unilateral due to increased pressure and inflammation caused by pus trapped within the sinus cavity. These patients usually have a history of a viral upper respiratory infection immediately before this and they have pyrexia with unilateral nasal obstruction. The vast majority of patients with acute sinusitis respond to antibiotics. Recurrent bacterial sinusitis is rare and anyone with more than two episodes of genuine bacterial sinusitis in 1 year should be investigated for evidence of poor immunity. Patients with chronic bacterial sinusitis rarely have any pain unless the sinus ostia are blocked and their symptoms are then the same as in acute sinusitis. Within the medical literature, there are texts that report that sphenoid sinusitis can cause headaches and, as with other acute sinus infections, intracranial or ophthalmolgical complications can occur. First, acute sphenoid sinusitis is rare and second, most of these patients respond to antibiotics. Batotrauma can cause short-lived pain in the sinus involved but there is always a clear history associated with diving or flying and, as the pressure within the sinus equalizes, the pain resolves within a few hours. Headaches are rarely due to sinusitis.

Does sphenopalatine endoscopic ganglion block have an effect in paroxysmal hemicrania? A case report

The authors report the case of a 69-year-old woman suffering from paroxysmal hemicrania (PH), intolerant to indomethacin and resistant to multiple therapies, in which sphenopalatine endoscopic ganglion block (SPG) dramatically modified the clinical outcome. SPG blockade could be considered a reasonable alternative in drug-resistant PH cases where indomethacin is contraindicated.

Cluster headache attacks in a woman previously struck by lightning: pathophysiology of the latent period

BACKGROUND

Cases of patients who developed cluster headache-like symptoms after different putative causes have been reported, indicating a direct relationship between brain lesion and this particular type of headache. Long term, delayed, neurological sequelae after lightning have also been described.

CASE REPORT

We describe the case of a woman who, at the age of 10, was struck by lightning. Six years later she developed cluster headache-like attacks.

CONCLUSION

We hypothesize that a relationship between the lightning and the cluster headache-like episodes observed in our patient. This case study may have helped throw some light into the still unknown pathophysiology of this particular type of primary headache.

Cluster headache and intracranial aneurysm

In the present study we describe the cases of two patients with cluster-like headache related to intracranial carotid artery aneurysm. One of these patients responded to verapamil prescription with headache resolution. In both cases the surgical clipping of the aneurysm resolved the cluster pain. These findings strongly suggest a pathophysiological link between the two conditions. The authors discuss the potential pathophysiological mechanisms underlying cluster-like headache due to intracranial carotid artery aneurysm.

Hemicrania Continua Secondary to an Ipsilateral Brainstem Lesion

We describe a 47-year-old woman with a 3-year history of a continuum mild-moderate right-side headache, with exacerbations, associated with stabbing volleys of pain on right orbit-temporal region (10/10) and right eye ptosis and lacrimation with conjunctival injection. The pain was completely abolished with indomethacin (100 mg per day). The diagnosis of hemicrania continua was made according to the International Headache Society (IHS) criteria. The headache presentation was precipitated by a stroke and a right-side brainstem lesion was present at magnetic resonance imaging. This case report shows anatomoclinical evidence of the involvement of brainstem structures on the pathophysiology of hemicrania continua.

Diagnosis and management of cervicogenic headache

Upper cervical pain and/or headaches originating from the C0 to C3 segments are pain-states that are commonly encountered in the clinic. The upper cervical spine anatomically and biomechanically differs from the lower cervical spine. Patients with upper cervical disorders fall into two clinical groups: (1) local cervical syndrome; and (2) cervicocephalic syndrome. Symptoms associated with various forms of both disorders often overlap, making diagnosis a great challenge. The recognition and categorization of specific provocation and limitation patterns lend to effective and accurate diagnosis of local cervical and cervicocephalic conditions.

Brain gray matter changes in migraine patients with T2-visible lesions: a 3-T MRI study

BACKGROUND AND PURPOSE

In migraine patients, functional imaging studies have shown changes in several brain gray matter (GM) regions. However, 1.5-T MRI has failed to detect any structural abnormality of these regions. We used a 3-T MRI scanner and voxel-based morphometry (VBM) to assess whether GM density abnormalities can be seen in patients with migraine with T2-visible abnormalities and to grade their extent.

METHODS

In 16 migraine patients with T2-visible abnormalities and 15 matched controls, we acquired a T2-weighted and a high-resolution T1-weighted sequence. Lesion loads were measured on T2-weighted images. An optimized version of VBM analysis was used to assess regional differences in GM densities on T1-weighted scans of patients versus controls. Statistical parametric maps were thresholded at P<0.001, uncorrected for multiple comparisons.

RESULTS

Compared with controls, migraine patients had areas of reduced GM density, mainly located in the frontal and temporal lobes. Conversely, patients showed increased periacqueductal GM (PAG) density. Compared with patients without aura, migraine patients with aura had increased density of the PAG and of the dorsolateral pons. In migraine patients, reduced GM density was strongly related to age, disease duration, and T2-visible lesion load (r ranging from -0.84 to -0.73).

CONCLUSIONS

Structural GM abnormalities can be detected in migraine patients with brain T2-visible lesions using VBM and a high-field MRI scanner. Such GM changes comprise areas with reduced and increased density and are likely related to the pathological substrates associated with this disease.

Cluster headache

Cluster headache is a relatively rare episodic headache disorder.Although traditionally it is believed to be a male-related disorder,the sex ratios are changing toward a more even balance. The disorder is characterized by bouts of daily headaches with pain-free remissions for extended times. Though attacks are brief, they are severe and typically are associated with autonomic symptoms. Medical therapies are the mainstay of treatment, with the goal being prevention of headaches in a cycle. Acute therapies, although effective, may be limited in usefulness because of attack frequency. Intractable cases may benefit from histamine desensitization and surgical treatments.

Facial migraine in a rhinological setting

This study aims to investigate the incidence of migraine involving the face in a rhinology clinic and to describe its characteristics. It is a study of a cohort of 973 patients consecutively presenting to the outpatient clinic with symptoms of facial pain and/or rhinosinusitis. The study subgroup consisted of patients with facial pain and migraine excluding cluster headache and paroxysmal hemicrania. We studied the features of 51 patients who had facial pain with migraine. The diagnosis was based on the criteria used by the International Headache Society and was also supported by the outcome and response to treatment after a mean of 2 years and 2 months. Of the 973 consecutive patients, 409 (42%) had symptoms of facial pain and/or head pain or pressure. Fifty-one (12%) had migraine. Of these, 39 (76%) had unilateral pain and, in 12 (24%), it was bilateral. The distribution affected the forehead and/or eye or cheek in 32 (63%) patients. Twenty-four (47%) had migraine isolated to the second division of the trigeminal nerve. Twelve per cent of patients attending a rhinology clinic with facial pain had migraine. Of particular interest were the 6% of patients with facial pain who had migraine confined to the second division of the trigeminal nerve. This entity is not widely recognized and has rarely been described in the literature.

Paroxysmal hemicrania and cluster headache: two discrete entities or is there an overlap?

Paroxysmal hemicrania has been described as an excruciating unilateral pain, which is usually ocular and frontotemporal with short-lasting (2-45 min), frequent attacks (usually more than five per day); with marked autonomic features (rhinorrhoea, nasal congestion, conjunctival injection, lacrimation) and unilateral to the pain. A response to indomethacin is essential using the current criteria for the diagnosis. It is a rare condition but when it occurs it is misdiagnosed as being due to sinusitis. A retrospective analysis of 11 patients seen in the period 1995-2001 suggests that there is an overlap between paroxysmal hemicrania and cluster headache. Four patients had all the characteristics of paroxysmal hemicrania and responded to indomethacin. Four other patients fulfilled the criteria except for the frequency and length of the attacks. They only had one attack per day and these lasted more than 2 h. Another patient had all the symptoms of paroxysmal hemicrania and did not respond to indomethacin, but responded to triptans and pizotifen. Patients with cluster headache typically respond to these. Two patients were unable to continue taking indomethacin owing to severe gastrointestinal upset. In the same period, we also had 30 patients with cluster headaches. There is increasing evidence that paroxysmal hemicrania and cluster headache share a similar pathogenesis and that they may not always be so discrete in either their response to indomethacin or their periodicity.

The medial pain system: neural representations of the motivational aspect of pain

In this article, we propose that the pathways mediating the motivational aspect of pain originate in laminae VII and VIII of the spinal cord, and in the deep layers of the spinal trigeminal complex, and projections from these areas reach three central structures where pain motivation is represented, the ventrolateral quadrant of the periaqueductal gray, posterior hypothalamic nucleus, and intralaminar thalamic nuclei. A final representation of the motivational aspect of pain is located within the anterior cingulate cortex, and this representation receives inputs from the intralaminar nuclei. Outputs from these representations reach premotor structures located in the medulla, striatum, and cingulate premotor cortex. We discuss pathways and structures that provide inputs to these representations, including those involved in producing involuntary (innate) and instrumental responses which occur in response to the recognition of stimuli associated with footshock and other nociceptive stimuli.

Two cases of medically and surgically intractable SUNCT: a reason for caution and an argument for a central mechanism

We report two cases of SUNCT that demonstrate the medically and surgically refractory nature of this disorder and support the hypothesis that the causative 'lesion' lies within the central nervous system. After both patients had failed medical therapies, the first underwent a glycerol rhizotomy, gammaknife radiosurgery and microvascular decompression of the trigeminal nerve. The second patient underwent gammaknife radiosurgery of the trigeminal root exit zone and two microvascular decompression surgeries. Neither patient benefited from these procedures. Currently, the first patient suffers from anaesthesia dolorosa and the second patient from unilateral deafness, chronic vertigo and dysequilibrium as a result of surgical trauma. These cases of SUNCT highlight the uncertainty regarding the role of surgery given the potential for significant morbidity. These cases also suggest that SUNCT originates and may be maintained from within the CNS and this central locus explains why SUNCT is not typically amenable to interventions aimed at the peripheral portion of the trigeminal nerve.