Mechanisms of Autonomic Disturbance in the Face During and Between Attacks of Cluster Headache

The Prevalence and Clinical Phenotypes of Cluster Headache in Relation with Latitude

PURPOSE OF REVIEW

Previous studies have indicated a possible link between the prevalence of cluster headache (CH) and sunlight exposure. However, this theory has yet to be tested systemically. In this article, we aim to examine how latitude affects the prevalence and phenotypes of CH.

RECENT FINDINGS

To our knowledge, there is by far no article describing the effect of latitude on disease phenotype; thus, we performed a literature review. We noted positive effects of latitude on 1-year prevalence, the proportion of chronic CH, and the proportion of miosis and/or ptosis. Latitude may affect the phenotypic presentations of cluster headache, probably partially mediated via temperature and sunlight variations. Still, other factors, such as environmental exposure to smoking and the genetic difference between the Eastern and Western populations, may participate in the pathogenesis and clinical manifestations of CH.

Characterization of trigeminal C-fiber reactivity through capsaicin-induced release of calcitonin gene-related peptide

OBJECTIVE

We hypothesized that the response of trigeminal dermal blood flow (DBF) in the trigeminal system and consecutive expansion of flare response to capsaicin would differ from the somatosensory system (arm). We also investigated whether there are differences between patients with migraine and healthy controls (HC).

BACKGROUND

Functional differences between the trigeminal and extracephalic somatosensory systems may partly explain the susceptibility for headaches in patients with migraine. Capsaicin-induced activation of nociceptive C-fibers in the skin is mainly mediated by calcitonin gene-related peptide (CGRP) and induces cutaneous vessel dilatation and flare response.

METHODS

Female patients with migraine (n = 38) and age-matched HC (n = 35) underwent DBF measurement at baseline and after topical capsaicin administration using laser speckle imaging. DBF before and after capsaicin stimulation was analyzed over ophthalmic nerve/maxillary nerve/mandibular nerve (V1/V2/V3) dermatomes and the forearm as an extracephalic control.

RESULTS

Capsaicin-induced DBF increased more in the trigeminal dermatomes than on the forearm. The V1 dermatome showed a smaller increase of DBF in patients with migraine compared to HC.

CONCLUSION

Our results suggest that the trigeminovascular system reacts differently from extracephalic areas, which may explain the trigeminal susceptibility to CGRP-mediated pain attacks. By demonstrating a different reactivity of the V1 dermatome in patients with migraine, our finding suggests that the first trigeminal branch is functionally different from the second and third branches; however, only in patients with migraine.

Systematic review of hematidrosis: Time for clinicians to recognize this entity

BACKGROUND

Hematidrosis is a sporadic disease, to a point where its existence is still denied up to date. It is also linked to stigmata, psychological roots, and religious beliefs, whih has strengthened clinicians' disbelief in hematidrosis.

AIM

To conduct a thorough review to classify the likelihood of hematidrosis cases.

METHODS

We searched PubMed, Science Direct, Medline, and Google Scholar, as well as four different preprint databases, including Medrxiv, Research Square, SSRN, and Biorxiv. We included studies from 1996 onwards, with no limitation on language. Hematidrosis was classified as "unlikely", "likely", and "highly likely".

RESULTS

There are 74 articles with 106 hematidrosis cases. India (n = 40) and China (n = 11) report the most cases. Patients are mostly female (76.5%) with a median age of 13 years. The head region is the most common bleeding site (n = 168/254). Headaches (26.9%) and abdominal pain (16.4%) are the most common prodromes. Beta-blockers (43%) and anxiolytic (23.2%) are the most commonly prescribed pharmacotherapy. Psychotherapy (37.5%) and counseling (32.5%) are the most utilized non-pharmacotherapy measures. Only 41.1% and 19.8% of all cases reach complete resolution and are highly likely to be hematidrosis, respectively.

CONCLUSION

Although hematidrosis is rare and the pathophysiology is still largely unknown, that does not mean hematidrosis does not exist. It is important to note that the most frequent trigger factors are either anxiety, fear, or excessive stress. Clinicians need to exclude other diagnoses and search for stressors to alleviate the bleeding.

Headache and Autonomic Dysfunction: a Review

PURPOSE OF REVIEW

We explore the anatomy of the central and peripheral autonomic pathways involved in primary headache as well as the mechanisms for secondary headache associated with disorders of the autonomic nervous system. The prevalence and clinical presentation of cranial and systemic autonomic symptoms in these conditions will be discussed, with a focus on recent studies.

RECENT FINDINGS

Several small studies have utilized the relationship between headache and the autonomic nervous system to identify potential biomarkers to aid in diagnosis of migraine and cluster headache. Headache in postural orthostatic tachycardia syndrome (POTS) has also been further characterized, particularly in its association with orthostatic headache and spontaneous intracranial hypotension (SIH). This review examines the pathophysiology of primary and secondary headache disorders in the context of the autonomic nervous system. Mechanisms of headache associated with systemic autonomic disorders are also reviewed.

Cluster Headache Pathophysiology—A Disorder of Network Excitability?

Patients’ accounts of cluster headache attacks, ictal restlessness, and electrophysiological studies suggest that the pathophysiology involves Aδ-fibre nociceptors and the network processing their input. Continuous activity of the trigeminal autonomic reflex throughout the in-bout period results in central sensitization of these networks in many patients. It is likely that several factors force circadian rhythmicity upon the disease. In addition to sensitization, circadian changes in pain perception and autonomic innervation might influence the excitability of the trigeminal cervical complex. Summation of several factors influencing pain perception might render neurons vulnerable to spontaneous depolarization, particularly at the beginning of rapid drops of the pain threshold (“summation headache”). In light of studies suggesting an impairment of short-term synaptic plasticity in CH patients, we suggest that the physiologic basis of CH attacks might be network overactivity—similarly to epileptic seizures. Case reports documenting cluster-like attacks support the idea of distinct factors being transiently able to induce attacks and being relevant in the pathophysiology of the disorder. A sustained and recurring proneness to attacks likely requires changes in the activity of other structures among which the hypothalamus is the most probable candidate.

Review of the external carotid plexus: anatomy, function, and clinical manifestations

The external carotid plexus is a combination of postganglionic sympathetic fibers derived from the superior cervical ganglion. This plexus travels along the external carotid artery and continues onto the artery’s branches. The external carotid plexus plays an important role in innervating the mid and lower face. Therefore, implications to the plexus may result in facial abnormalities. Herein, we review the anatomy, function, and review its clinical applications.

The biological clock in cluster headache: A review and hypothesis

Objective

To review and discuss the putative role of light, sleep, and the biological clock in cluster headache.

Discussion

Cluster headache attacks are believed to be modulated in the hypothalamus; moreover, the severe pain and typical autonomic cranial features associated with cluster headache are caused by abnormal activity of the trigeminal-autonomic reflex. The temporal pattern of cluster headache attacks suggests involvement of the biological clock, and the seasonal pattern is influenced by the number of daylight hours. Although sleep is often reported as a trigger for cluster headache attacks, to date no clear correlation has been established between these attacks and sleep stage.

Conclusions

We hypothesize that light, sleep, and the biological clock can change the brain’s state, thereby lowering the threshold for activating the trigeminal-autonomic reflex, resulting in a cluster headache attack. Understanding the mechanisms that contribute to the daily and seasonal fluctuations in cluster headache attacks may provide new therapeutic targets.

Chronic persistent Horner's syndrome in trigeminal autonomic cephalalgia subtypes and alleviation with treatment: two case reports

Background

The trigeminal autonomic cephalalgias are a group of primary headache syndromes marked by severe head pain and associated cranial autonomic symptoms which can include a full or partial Horner’s syndrome. Rarely, the eye-related symptoms will become fixed even between headache attacks. There is minimal documentation that the Horner’s syndrome can be reversed if successful treatment of the underlying headache disorder is initiated.

Case reports

Two cases are presented of trigeminal autonomic cephalalgia subtypes with chronic persistent Horner’s syndromes that alleviated with treatment of the underlying primary headache disorder. Patient 1, an 82-year-old Caucasian woman, presented with hemicrania continua with a partial Horner’s syndrome that was present for 2 years. She was unable to take indomethacin as she was on anticoagulation. After a C2–3 diagnostic facet injection, not only did she become pain free but her ptosis completely resolved. She then underwent a radiofrequency facet neurotomy with complete alleviation of head pain and complete resolution of her ptosis. Patient 2, a 21-year-old Caucasian woman, presented with long-lasting autonomic symptoms with hemicrania syndrome and a fixed miosis and ptosis of 6 months’ duration. After achieving 2 months of pain freedom on indomethacin her Horner’s syndrome completely resolved.

Conclusion

A chronic fixed partial or full Horner’s syndrome can occur in trigeminal autonomic cephalalgia subtypes, but it can also be reversed in patients with treatment even after months to years of duration. This would suggest that the sympathetic dysfunction leading to the eye-related symptoms is from irritation of the sympathetic chain rather than permanent injury as the result of vasodilatory trauma after trigeminal autonomic reflex activation.

Cluster Headache: Epidemiology, Pathophysiology, Clinical Features, and Diagnosis

Cluster headache is a primary headache disorder affecting up to 0.1% of the population. Patients suffer from cluster headache attacks lasting from 15 to 180 min up to 8 times a day. The attacks are characterized by the severe unilateral pain mainly in the first division of the trigeminal nerve, with associated prominent unilateral cranial autonomic symptoms and a sense of agitation and restlessness during the attacks. The male-to-female ratio is approximately 2.5:1. Experimental, clinical, and neuroimaging studies have advanced our understanding of the pathogenesis of cluster headache. The pathophysiology involves activation of the trigeminovascular complex and the trigeminal-autonomic reflex and accounts for the unilateral severe headache, the prominent ipsilateral cranial autonomic symptoms. In addition, the circadian and circannual rhythmicity unique to this condition is postulated to involve the hypothalamus and suprachiasmatic nucleus. Although the clinical features are distinct, it may be misdiagnosed, with patients often presenting to the otolaryngologist or dentist with symptoms. The prognosis of cluster headache remains difficult to predict. Patients with episodic cluster headache can shift to chronic cluster headache and vice versa. Longitudinally, cluster headache tends to remit with age with less frequent bouts and more prolonged periods of remission in between bouts.

Carotid dissection presenting as a prolonged cluster-like headache in a patient with episodic cluster headache

We present a patient with known episodic cluster headache, who presented with cluster-like headache in the course of internal carotid artery dissection (ICAD) and discuss possible pathophysiological links between the two diseases. It is well known that cluster-like headache could be the presenting symptom of ICAD. However, ICAD occurring in a patient with a known episodic cluster headache was only once previously described. In the end of the manuscript, we propose red flags to help clinicians differentiate between primary cluster headache and cluster-like attacks masking underlying ICAD. Finally, we raise the question whether at least some proportion of those patients with cluster headache and Horner syndrome previously classified as a primary headache disorder might have been secondary cases to ICAD.

Identifying a gene expression signature of cluster headache in blood

Cluster headache is a relatively rare headache disorder, typically characterized by multiple daily, short-lasting attacks of excruciating, unilateral (peri-)orbital or temporal pain associated with autonomic symptoms and restlessness. To better understand the pathophysiology of cluster headache, we used RNA sequencing to identify differentially expressed genes and pathways in whole blood of patients with episodic (n = 19) or chronic (n = 20) cluster headache in comparison with headache-free controls (n = 20). Gene expression data were analysed by gene and by module of co-expressed genes with particular attention to previously implicated disease pathways including hypocretin dysregulation. Only moderate gene expression differences were identified and no associations were found with previously reported pathogenic mechanisms. At the level of functional gene sets, associations were observed for genes involved in several brain-related mechanisms such as GABA receptor function and voltage-gated channels. In addition, genes and modules of co-expressed genes showed a role for intracellular signalling cascades, mitochondria and inflammation. Although larger study samples may be required to identify the full range of involved pathways, these results indicate a role for mitochondria, intracellular signalling and inflammation in cluster headache.

Spontaneous extracranial hemorrhagic phenomena in primary headache disorders: A systematic review of published cases

Background Head pain is a cardinal feature of primary headache disorders (PHDs) and is often accompanied by autonomic and vasomotor symptoms and/or signs. Spontaneous extracranial hemorrhagic phenomena (SEHP), including epistaxis, ecchymosis, and hematohidrosis (a disorder of bleeding through sweat glands), are poorly characterized features of PHDs. Aim To critically appraise the association between SEHP and PHDs by systematically reviewing and pooling all reports of SEHP associated with headaches. Methods Advanced searches using the PubMed/MEDLINE, Web of Science, Cochrane Library, Google Scholar, and ResearchGate databases were carried out for clinical studies by combining the terms "headache AND ecchymosis", "headache AND epistaxis", and "headache AND hematohidrosis" spanning all medical literature prior to October 10, 2015. Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology guidelines were applied. Results A total of 105 cases of SEHP associated with PHDs (83% migraine and 17% trigeminal autonomic cephalgias) were identified (median age 27 years, male to female ratio 1:2.3); 63% had epistaxis, 33% ecchymosis, and 4% hematohidrosis. Eighty-three percent of studies applied the International Classification of Headache Disorders diagnostic criteria. Eighty percent of the reported headaches were episodic and 20% were chronic. Twenty-four percent of studies reported recurrent episodes of SEHP. Conclusions Our results suggest that SEHP may be rare features of PHDs. Future studies would benefit from the systematic characterization of these phenomena.

The cavernous sinus in cluster headache - a quantitative structural magnetic resonance imaging study

Background It has been hypothesized that a constitutionally narrow cavernous sinus might predispose individuals to cluster headache. Cavernous sinus dimensions, however, have never been assessed. Methods In this case-control study, we measured the dimensions of the cavernous sinus, skull base, internal carotid and pituitary gland with high-resolution T2-weighted magnetic resonance imaging in 25 episodic, 24 chronic and 13 probable cluster headache patients, 8 chronic paroxysmal hemicrania patients and 22 headache-free controls. Dimensions were compared between groups, correcting for age, sex and transcranial diameter. Results On qualitative inspection, no relevant pathology or anatomic variants that were previously associated with cluster headache or chronic paroxysmal hemicranias were observed in the cavernous sinus or paracavernous structures. The left-to-right transcranial diameter at the temporal fossa level (mean ± SD) was larger in the headache groups (episodic cluster headache: 147.5 ± 7.3 mm, p = 0.044; chronic cluster headache: 150.2 ± 7.3 mm, p < 0.001; probable cluster headache: 146.0 ± 5.3 mm, p = 0.012; and chronic paroxysmal hemicrania: 145.2 ± 9.4 mm, p = 0.044) compared with controls (140.2 ± 8.0 mm). After adjusting for transcranial diameter and correcting for multiple comparisons, there were no differences in the dimensions of the cavernous sinus and surrounding structures between headache patients and controls. Conclusion Patients with cluster headache or chronic paroxysmal hemicrania had wider skulls than headache-free controls, but the proportional dimensions of the cavernous sinus were similar.

Evaluation of interictal autonomic function during attack and remission periods in cluster headaches

Objective

To investigate which part of the autonomic system is mainly involved and assess the sensitivity of face sympathetic skin response in cluster headache.

Material and methods

The study sample consisted of 19 drug-free cluster headache patients (16 males, three females) and 19 healthy volunteers. Demographic features and pain characteristics were thoroughly identified. Dysautonomic symptoms were evaluated during attack and remission periods of cluster headache patients. Orthostatic hypotension, R-R interval variation and sympathetic skin responses obtained from the face and four extremities were evaluated and the sensitivity of face sympathetic skin responses was assessed in contrast to extremity sympathetic skin responses.

Results

All sympathetic skin responses of face and extremities could be obtained during attack and remission periods. On the symptomatic side, mean latency of face sympathetic skin responses was longer compared to the asymptomatic side and controls (p = 0.02, p = 0.004). There were no differences in latency or amplitude of extremity sympathetic skin responses between symptomatic and asymptomatic sides and controls. No significant relationship was determined between sympathetic skin responses, R-R interval variation, orthostatic hypotension and cluster headache clinical features.

Conclusion

Sympathetic hypoactivity of the face seems to predominate the pathophysiology of cluster headache. Face sympathetic skin responses might be more sensitive compared to extremity sympathetic skin response in demonstrating dysautonomic symptoms in cluster headache patients.

Posterior hypothalamic modulation of ocular-responsive trigeminal subnucleus caudalis neurons is mediated by Orexin-A and Orexin1 receptors

Orexin-A (OxA) is synthesized in posterior and lateral regions of the hypothalamus and contributes to homeostatic regulation of body functions including pain modulation. To determine if orexinergic mechanisms contribute to posterior hypothalamus (PH)-induced modulation of ocular input to subnucleus caudalis/upper cervical (Vc/C1) neurons, the orexin-1 receptor antagonist SB334867 was applied to the dorsal brainstem surface prior to PH disinhibition, by bicuculline methiodide, in male rats under isoflurane anesthesia. Ocular input to Vc/C1 units by bright light or hypertonic saline was markedly reduced by PH disinhibition and reversed completely by local Vc/C1 application of SB334867. OxA applied to the Vc/C1 surface mimicked the effects of PH disinhibition in a dose-dependent manner. OxA-induced inhibition was prevented by co-application of SB334867, but not by the orexin-2 receptor antagonist TCS Ox2 29. PH disinhibition and local OxA application also reduced the high threshold convergent cutaneous receptive field area of ocular units, suggesting widespread effects on somatic input to Vc/C1 ocular units. Vc/C1 application of OxA or SB334867 alone did not affect the background discharge of ocular units and suggested that the PH-OxA influence on ocular unit activity was not tonically active. Vc/C1 application of OxA or SB334867 alone also did not alter mean arterial pressure, whereas PH disinhibition evoked prompt and sustained increases. These results suggest that stimulus-evoked increases in PH outflow acts through OxA and orexin-1 receptors to alter the encoding properties of trigeminal brainstem neurons responsive to input from the ocular surface and deep tissues of the eye.

Headache plus: trigeminal and autonomic features in a case of cervicogenic headache responsive to third occipital nerve radiofrequency ablation

OBJECTIVE

To describe a case of cervicogenic headache with associated autonomic features and pain in a trigeminal distribution, all of which responded to third occipital nerve radiofrequency ablation.

DESIGN

Single case report.

SETTING

Massachusetts General Hospital Center for Pain Medicine.

PATIENTS

A 38-year-old woman with history of migraines and motor vehicle accident.

INTERVENTIONS

Right third occipital nerve diagnostic blocks and radiofrequency lesioning.

OUTCOME MEASURES

Pain reduction; physical findings, including periorbital and mandibular facial swelling, tearing, conjunctival injection, and allodynia; and use of opioid and non-opioid pain medicines.

RESULTS

The patient had complete relief of her pain and autonomic symptoms, and was able to stop all pain medications following a dedicated third occipital nerve lesioning.

CONCLUSIONS

This case illustrates the diagnostic and therapeutic complexity of cervicogenic headache and the overlap with other headache types, including trigeminal autonomic cephalgias and migraine. It represents a unique proof of principle in that not only trigeminal nerve pain but also presumed neurogenic inflammation can be relieved by blockade of cervical nociceptive inputs. Further investigation into shared mechanisms of headache pathogenesis is warranted.

Differential diagnosis of orofacial pain and temporomandibular disorder

When a patient complains of orofacial pain, health care providers must make a correct diagnosis. Doing this can be difficult, since various signs and symptoms may not be specific for 1 particular problem or disorder. One initially should formulate a broad differential diagnosis that can be narrowed after analysis of the history and examination. In this article, orofacial pain is categorized as being caused by: intracranial pain, headaches, neuropathic pain, intraoral pain, temporomandibular disorder, cervical pain, pain related to anatomically associated structures, referred pain, or mental illness.

SUNA and red ear syndrome: a new association and pathophysiological considerations

Red ear syndrome (RES) is characterised by attacks of unilateral or bilateral burning ear pain associated with erythema. Primary and secondary forms have been described. Primary RES appears to have a frequent association with primary headaches especially migraine. Here, we describe the case of a woman with short-lasting unilateral neuralgiform attacks with cranial autonomic symptoms (SUNA) and recurrent episodes of ipsilateral red ear triggerable by cutaneous stimulation. Lamotrigine was beneficial for her SUNA but not for the RES. Both these disorders are extremely rare therefore their coexistence in the same individual may suggest similar pathophysiological mechanisms rather than a chance association.

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

BACKGROUND

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

METHODS

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

CONCLUSION

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

Bilateral paroxysmal cephalalgia: a novel indomethacin-responsive primary headache syndrome?

INTRODUCTION

Paroxysmal hemicrania (PH) is a primary headache disorder characterised by frequent, short-lasting, very severe, strictly unilateral attacks occurring in association with cranial autonomic features. A striking feature of this disorder is its clear response to indomethacin.

CASE REPORT

In contrast to this stereotypic presentation, we describe a man with indomethacin-responsive headaches that have a temporal profile similar to that of PH but whose attacks have a bilateral distribution without associated cranial autonomic features.

DISCUSSION

There have been several case reports of patients presenting with short-lasting, frequent, bilateral headaches responding to indomethacin, without cranial autonomic features. These cases have been described as representing bilateral PH although strict unilaterality of pain and cranial autonomic phenomena are cardinal features of PH. These cases may represent a novel indomethacin-responsive syndrome and therefore, for now, should be studied separately from PH until their pathophysiological basis is better understood.

Headache in pregnancy: a nuisance or a new sense?

Headache is a very commonly encountered symptom in pregnancy and is usually due to primary headache disorders which are benign in nature. It can however be quite debilitating for some women who may need therapeutic treatment of which there are several options safe to use in pregnancy. It is equally important though to recognise that headache may be a sign of serious underlying pathology. This paper aims to provide a clinically useful guidance for differentiation between primary and secondary headaches in pregnancy. The primary headache disorders and their management in pregnancy are explored in depth with brief overviews of the causes for secondary headaches and their further investigation and management.

Primary headache syndromes in systemic mastocytosis

Aim: To investigate the relationship between clinical mast cell activity and primary headache syndromes.

Methods: We surveyed individuals with systemic mastocytosis, an uncommon disorder associated with increased mast cell activity. Diagnoses of primary headache syndromes in addition to the relationship of headache and symptoms of mastocytosis were ascertained.

Results: A response rate of 64/148 (43.2%) was achieved. Headache diagnoses in our respondents (n = 64) were largely migraine (37.5%) and tension-type headaches (17.2%). Typical aura with and without migraine headache was highly represented in our patient population (n = 25, 39%). Three individuals met criteria for primary cough headache (4.7%). Symptoms reflective of mast cell activity were significantly greater in individuals reporting headaches. Patients experiencing headache concurrently with mastocytosis flairs were more likely to be male (p = 0.002), have histaminergic symptoms, such as itching (p = 0.02) and runny nose (p = 0.03), and have unilateral cranial autonomic features (p = 0.04). However, using standardized International Headache Society criteria, we did not identify individuals with cluster headache or other trigeminal autonomic cephalalgias in this population.

Conclusions: Our observational survey-based data supports a clinical relationship between mast cell activity and primary headache syndromes. Generalizability of our results is limited by the low response rate and possible tertiary referral bias.

Immersing the foot in painfully-cold water evokes ipsilateral extracranial vasodilatation

Temporal pulse amplitude was recorded bilaterally in 56 participants before, during and after three ice-water immersions of the foot. Half of the participants were told that prolonged exposure to freezing temperatures could cause frostbite. Increases in pulse amplitude were greater in the ipsilateral than contralateral temple during and after the three foot-immersions. Although pulse amplitude decreased after threatening instructions and repeated immersion of the foot, the vasodilator response persisted during all three immersions. These findings suggest that nociceptive stimulation of the foot evokes an ipsilateral supra-spinal extracranial vasodilator response, possibly as part of a broader defense response.

The importance of autonomic symptoms in trigeminal neuralgia

Object

Autonomic symptoms can occur in association with the facial pain of trigeminal neuralgia (TN). The distinction between first division (V1) TN and trigeminal autonomic cephalgias, particularly short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), can be difficult. The goal in this study was to investigate the frequency of autonomic symptoms with TN and to determine their effect on surgical outcome.

Methods

The authors sent questionnaires and reviewed the records of 92 patients who underwent surgical procedures for TN to obtain visual analog scale scores for pain before and after surgery and to determine the location of the pain and the presence of autonomic symptoms.

Results

Sixty-seven percent of patients had at least 1 autonomic symptom, and 14% had 4 or more autonomic symptoms associated with their pain. With V1 pain, the most common autonomic symptoms were conjunctival injection, ptosis, and excessive tearing. With pain involving the second division (V2), facial swelling was the most common autonomic symptom. Excessive salivation occurred most often when the pain involved the third division (V3). In patients who underwent microvascular decompression (MVD), visual analog scores for pain showed significantly greater improvement postoperatively in those who had no preoperative autonomic symptoms than in those who reported autonomic symptoms. There was also a significantly greater number of patients who were pain free postoperatively in the group without autonomic symptoms. There were 3 patients with V1 facial pain associated with conjunctival injection and tearing who, in retrospect, fulfilled all the current diagnostic criteria for SUNCT. These patients underwent MVD, during which a vessel was found to compress the trigeminal nerve. Postoperatively, the 3 patients experienced complete and long-lasting pain relief.

Conclusions

The presence of autonomic symptoms in TN correlated with a worse prognosis for pain relief after MVD. First division TN with autonomic symptoms can present identically to SUNCT but can respond to MVD if there is a compressive vessel. Neurosurgeons should be aware of SUNCT, especially in patients with V1 TN and autonomic symptoms, to ensure that all potential medical therapies have been tried prior to surgical treatment.

Voluntarily produced increases in heart rate variability modulate autonomic effects of endotoxin induced systemic inflammation: an exploratory study

Exposure of healthy people to lipopolysaccharide (LPS; endotoxin) produces a pro-inflammatory response, subjective symptoms, and decreased heart rate variability (HRV). Given the efficacy of HRV biofeedback (BF) for treating asthma, the large autonomic effects of HRV BF, and the link between vagus nerve activity and inflammation, we hypothesized that HRV BF would dampen the acute manifestations of systemic inflammation induced by LPS challenge. Healthy participants age 18-40 were randomly assigned to four-one-hour training sessions of either HRV BF (n = 6) or a control 15/min paced breathing condition (n = 5) prior to acute experimentally induced LPS exposure. Participants were coached to do the procedures for 10 min each at five hourly time points after LPS injection, and then 2 h later. Subjective symptoms, HRV parameters, and plasma cytokine levels were measured at each time point, 2 h afterward, and the following morning. Participants were able to perform the procedures both during four pre-exposure training sessions and while experiencing LPS-induced symptoms. The HRV BF group showed significant attenuation of the LPS-induced decline in HRV for the 6 h following LPS exposure, suggesting that HRV BF decreased autonomic dysfunction produced by LPS-induced inflammation. HRV BF also reduced symptoms of headache and eye sensitivity to light, but did not affect LPS-induced levels of pro-inflammatory cytokines or symptoms of nausea, muscle aches, or feverishness. Further evaluation of HRV BF appears to be warranted among patients with inflammatory conditions.

Cluster headache associated with a sixth nerve palsy: a case report

BACKGROUND

Cluster headache is a rare primary headache disorder characterized by recurrent, stereotyped short-lasting attacks of severe, unilateral head pain accompanied by autonomic symptoms.

METHODS/RESULTS

Ophthalmic features such as conjunctival injection, lacrimation, ptosis and miosis occur in the vast majority of patients with cluster headache, whereas co-existent ocular movement disorders are rare.

CONCLUSIONS

To the best of our knowledge, only two documented cases of cluster headache with external ocular movement disorders have been reported. We describe herein an additional case with this unusual finding and discuss the putative pathophysiology of cluster headache associated with ophthalmoparesis.

Trigeminal autonomic cephalalgias: a review and implications for dentistry

BACKGROUND

The authors review the epidemiology, clinical features, pathophysiology, diagnosis, treatment, orofacial presentations and dental implications of trigeminal autonomic cephalalgias (TACs): cluster headache (CH), paroxysmal hemicrania (PH) and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT).

TYPES OF STUDIES REVIEWED

The authors conducted PUBMED searches for the period from 1968 through 2007 using the terms "trigeminal autonomic cephalalgias," "cluster headache," "paroxysmal hemicrania," "short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing," "epidemiology," "pathophysiology," "treatment," "oral," "facial" and "dentistry." They gave preference to articles reporting randomized, controlled trials and those published in English-language peer-reviewed journals.

RESULTS

TACs refers to a group of headaches characterized by unilateral head pain, facial pain or both with accompanying autonomic features. Although their pathophysiologies are unclear, CH, PH and SUNCT may be differentiated according to their clinical characteristics. Current treatments for each of the TACs are useful in alleviating the pain, with few refractory cases requiring surgical intervention. Patients with TACs often visit dental offices seeking relief for their pain.

CLINICAL IMPLICATIONS

Although the prevalence of TACs is small, it is important for dentists to recognize the disorder and refer patients to a neurologist. This will avoid the pitfall of administering unnecessary and inappropriate traditional dental treatments in an attempt to alleviate the neurovascular pain.

Headache and pregnancy

BACKGROUND

Many women who suffer from migraine and tension-type headaches (TTHs) have an improvement in the frequency of these headaches during pregnancy. At the same time pregnancy predisposes women to a number of potentially life-threatening conditions which can present with headache. Accurate diagnosis and treatment of headache during pregnancy is essential.

REVIEW SUMMARY

The primary objectives of this review are to: (1) Summarize the natural history of primary headache disorders, including migraine, tension-type, and cluster headaches during pregnancy, as well as the impact of migraine on pregnancy outcomes and complications.(2) Summarize the therapeutic options and strategies for managing headaches in pregnancy and (3) Discuss the causes of secondary headaches and the diagnostic evaluation for new onset headache during pregnancy.

CONCLUSION

Primary headache disorders, in particular TTHs and migraines, generally improve during pregnancy. However the frequency of improvement varies greatly. Because the pathophysiology of both migraines and TTHs is poorly understood, this limits our ability to predict improvement. Future research should be focused on headache pathophysiology and the effect of ovarian hormones and the pregnant state on headache pathogenesis.

Two cases of symptomatic cluster-like headache suggest the importance of sympathetic/parasympathetic balance

Despite several reports on symptomatic cluster-like headache, there is no clear explanation of how different lesions thought to be causative are related to cluster-like headache. On the basis of two additional cases of symptomatic cluster headache, we discuss the possibility that an acute imbalance of the autonomic nervous system, namely a net overactivity of the parasympathetic system, may be able to trigger these headache attacks in patients who probably have an additional individual predisposition to react with a cluster-like headache. Such an imbalance can be due to an increase in parasympathetic tone (e.g. stimulation of parasympathetic fibres) or to a reduction of the sympathetic tone (e.g. a lesion of the sympathetic fibres).