Focal headache during balloon inflation in the internal carotid and middle cerebral arteries

Association of preoperative aneurysmal wall enhancement with relief of chronic headache after surgical clipping of unruptured intracranial aneurysms

OBJECTIVE

To investigate the association between chronic headache outcome and aneurysmal wall enhancement (AWE) on high-resolution vessel wall imaging (HR-VWI) in patients with unruptured intracranial aneurysms (UIAs) who underwent microsurgical clipping.

METHODS

Two hundred seventy-four UIA patients were retrospectively analyzed. Patients were grouped according to presence of AWE. AWE was subclassified as focal or uniform. Clinical and imaging data were recorded. Headache was evaluated using the 10-point numerical rating scale and Headache Impact Test-6 before and 6 months after surgery.

RESULTS

The proportions of patients reporting chronic headache in the no AWE, focal wall enhancement (FWE), and uniform wall enhancement (UWE) groups were 5.7%, 24.8%, and 41.8%, respectively. All patients in the UWE group who reported headache before surgery experienced headache improvement after surgery. Decrease in headache severity was greater in the UWE group than in the FWE group. Multivariate binary logistic regression showed that FWE (odds ratio (OR) 0.490; 95% confidence interval (CI), 0.262-0.917; p = 0.026) and small intraluminal thrombus (OR 0.336; 95% CI, 0.142-0.795; p = 0.013) were independent factors protective against preoperative headache. FWE (OR 0.377; 95% CI, 0.195-0.728; p = 0.004) and small intraluminal thrombus (OR 0.235; 95% CI, 0.088-0.630; p = 0.004) were independent predictors of no headache relief after surgery.

CONCLUSIONS

AWE on HR-VWI is associated with relief of chronic headache after surgical clipping in patients with UIAs. Incidence of chronic headache was highest in patients exhibiting UWE. These patients also experienced the greatest improvement in headache after surgical clipping.

CLINICAL RELEVANCE STATEMENT

This study revealed that high-resolution vessel wall imaging can demonstrate aneurysmal wall plaque and intraluminal thrombus, which may be prognostic imaging markers for chronic headache in patients with unruptured intracranial aneurysms.

KEY POINTS

• Aneurysmal wall enhancement may be associated with chronic headache. • Incidence of chronic headache was highest in patients with aneurysms exhibiting uniform wall enhancement. • Patients with aneurysms exhibiting uniform wall enhancement experienced the greatest improvement in headache after clipping.

Effects of PDE-3 inhibition in persistent post-traumatic headache: evidence of cAMP-dependent signaling

BACKGROUND

Phosphodiesterase 3 (PDE-3) inhibition have been implicated in the neurobiologic underpinnings of migraine. Considering the clinical similarities between migraine and persistent post-traumatic headache (PPTH), we aimed to ascertain whether PDE-3 inhibition can elicit migraine-like headache in persons with PPTH.

METHODS

We tested cilostazol, which inhibits PDE-3, in a randomized, double-blind, placebo-controlled, two-way crossover study involving persons with PPTH attributed to mild traumatic brain injury. The randomized participants were allocated to receive oral administration of either 200-mg cilostazol or placebo (calcium tablet) on two separate experiment days. The primary end point was the incidence of migraine-like headache during a 12-hour observation window post-ingestion. The secondary endpoint was the area under the curve (AUC) for reported headache intensity scores during the same observation window.

RESULTS

Twenty-one persons underwent randomization and completed both experiment days. The mean participants' age was 41.4 years, and most (n = 17) were females. During the 12-hour observation window, 14 (67%) of 21 participants developed migraine-like headache post-cilostazol, in contrast to three (14%) participants after placebo (P =.003). The headache intensity scores were higher post-cilostazol than after placebo (P <.001).

CONCLUSIONS

Our results provide novel evidence showing that PDE-3 inhibition can elicit migraine-like headache in persons with PPTH. Given that PDE-3 inhibition increases intracellular cAMP levels, our findings allude to the potential therapeutic value of targeting cAMP-dependent signaling pathways in the management of PPTH. Further investigations are imperative to substantiate these insights and delineate the importance of cAMP-dependent signaling pathways in the neurobiologic mechanisms underlying PPTH.

CLINICALTRIALS

GOV IDENTIFIER

NCT05595993.

The anatomy of head pain

Pain-sensitive structures in the head and neck, including the scalp, periosteum, meninges, and blood vessels, are innervated predominantly by the trigeminal and upper cervical nerves. The trigeminal nerve supplies most of the sensation to the head and face, with the ophthalmic division (V1) providing innervation to much of the supratentorial dura mater and vessels. This creates referral patterns for pain that may be misleading to clinicians and patients, as described by studies involving awake craniotomies and stimulation with electrical and mechanical stimuli. Most brain parenchyma and supratentorial vessels refer pain to the ipsilateral V1 territory, and less commonly the V2 or V3 region. The upper cervical nerves provide innervation to the posterior scalp, while the periauricular region and posterior fossa are territories with shared innervation. Afferent fibers that innervate the head and neck send nociceptive input to the trigeminocervical complex, which then projects to additional pain processing areas in the brainstem, thalamus, hypothalamus, and cortex. This chapter discusses the pain-sensitive structures in the head and neck, including pain referral patterns for many of these structures. It also provides an overview of peripheral and central nervous system structures responsible for transmitting and interpreting these nociceptive signals.

De novo headache in ischemic stroke patients treated with thrombectomy: a prospective study

Background and aim

Headache attributed to intracranial endovascular procedures is described in the ICHD-3. Our aim was to study the frequency and characteristics of headache specifically related to thrombectomy in patients with ischemic stroke.

Methods

Prospective evaluation of clinical features of headache after thrombectomy using an ad hoc questionnaire.

Results

One hundred seventeen patients were included (52.1% females). Most had an anterior circulation artery occlusion (91.5%). 93 (79.5%) received general anaesthesia. 111 (94.9%) required stent retriever, 21 (24.4%) angioplasty and 19 (16.2%) aspiration thrombectomy. 31 (26.5%; 95% CI 18.8–35.5%) had headache related to thrombectomy, and it was associated with a history of primary headache (p = 0.004). No differences about sex, initial NIHSS score, or the type or complexity of the procedure were observed. Headache was usually moderate and oppressive, ipsilateral to the artery occlusion and usually lasted less than 48 hours.

Conclusions

Almost one-third of patients with ischemic stroke who undergo endovascular thrombectomy experience headache in the first 24 hours, occurring more frequently in patients who had a previous history of headaches regardless of the procedure complexity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01455-3.

- About one third of the patients who undergo a thrombectomy for acute stroke experience headache directly related to the procedure.

- Having a previous history of primary headache is associated with the presence of headache after thrombectomy.

- Headache related to thrombectomy usually coincides with the distribution of the affected artery, although it is bilateral in 45% of the cases, mostly oppressive, of an average duration between 1 and 2 days and of a moderate intensity.

The applicability research of the diagnostic criteria for 6.7.2 angiography headache in the international classification of headache disorders-3rd edition

Background

Angiography headache (AH) is common but not negligible, and the criteria for AH have been based on only a few studies. The purpose of this study was to investigate the incidence, risk factors and possible mechanism of AH and reappraise the diagnostic criteria for AH in the International Classification of Headache Disorders 3 (ICHD-3).

Methods

Two hundred and seventy-nine patients completed this prospective, non-randomized study, including 107 patients who underwent cerebral angiography, 101 patients who underwent coronary intervention and 71 patients who underwent extremities arterial intervention. Patients were followed up with questionnaires immediately after the procedure and 24 h, 72 h, 1 week and 2 weeks after the procedure.

Results

The incidence of headache was 22.4% (24/107) in cerebral angiography group, 23.8% (24/101) in coronary intervention group, and 16.9% (12/71) in extremities arterial intervention group. Headache still occurred in 12.1% (13/107), 14.9% (15/101) and 11.3% (8/71) of patients 24 h after the procedure in the three groups, respectively. Two types of headache were observed in cerebral angiography group and coronary intervention group, one during and one after the procedure, while only postoperative headache was observed in extremities arterial intervention group. Previous headache history was a risk factor for headache in the three groups (p = 0.003 in cerebral angiography group, p = 0.006 in coronary intervention group, and p = 0.016 in extremities arterial intervention group). In addition, female (p = 0.008) was a risk factor for cerebral angiography group. Headache characteristics were described in detail.

Conclusions

The diagnostic criteria for 6.7.2 angiography headache in ICHD-3 may miss a number of cerebral AH with onset later than 24 h after the procedure. Therefore, it is recommended to revise it according to the literature and further studies. The incidence of headache was high during and after angiography and interventional procedure. It was suggested that the definition of headache due to coronary intervention and headache due to extremities arterial intervention should be added in ICHD.

Mechanisms of migraine as a chronic evolutive condition

Understanding the mechanisms of migraine remains challenging as migraine is not a static disorder, and even in its episodic form migraine remains an "evolutive" chronic condition. Considerable progress has been made in elucidating the pathophysiological mechanisms of migraine, associated genetic factors that may influence susceptibility to the disease, and functional and anatomical changes during the progression of a migraine attack or the transformation of episodic to chronic migraine. Migraine is a life span neurological disorder that follows an evolutive age-dependent change in its prevalence and even clinical presentations. As a disorder, migraine involves recurrent intense head pain and associated unpleasant symptoms. Migraine attacks evolve over different phases with specific neural mechanisms and symptoms being involved during each phase. In some patients, migraine can be transformed into a chronic form with daily or almost daily headaches. The mechanisms behind this evolutive process remain unknown, but genetic and epigenetic factors, inflammatory processes and central sensitization may play an important role.

Headache Outcomes After Coil Embolization in Patients with Unruptured Intracranial Aneurysms: Do They Get Better or Worse? A Prospective Analysis

BACKGROUND

To investigate the association between headache outcomes and coil embolization and to identify potential factors associated with different headache outcomes in patients with unruptured intracranial aneurysms (UIAs) after treatment with coil embolization.

METHODS

A prospective study of patients with planned coil embolization for UIAs was conducted. The changes in headache patterns, headache-related disability, and depression were assessed before coil embolization and at 3 days and 2 and 6 weeks after coil embolization. All variables were analyzed to identify factors associated with different headache outcomes.

RESULTS

Fifty-nine (72%) of 82 patients reported headaches before coil embolization. Of these, improvements in the severity of headaches were reported by 42 patients (71%). In addition to a significant reduction in headache severity, significant reductions in headache-related disability and depression scores also were observed. Demographic factors, aneurysmal characteristics, or procedural factors were not found to be significantly associated with improvement in the severity of headaches after coil embolization. In addition, the number of microemboli on diffusion-weighted imaging was not significantly associated with improvement of headaches after coil embolization. Twenty-three patients reported no headaches before coil embolization, and 3 (13%) patients reported new-onset headaches after coil embolization. All new-onset headaches were mild and dull in nature without combined symptoms in the temporal area.

CONCLUSIONS

Our study suggested that regardless of headache characteristics, the aneurysm size (even those <5 mm in diameter), technique used (stent-assisted or not stent-assisted), and coil embolization of UIAs resulted in headache improvement in most patients with pretreatment headaches.

Characteristics of Headache After an Intracranial Endovascular Procedure: A Prospective Observational Study

BACKGROUND

Two editions of the International Classification of Headache Disorders (ICHD) diagnostic criteria for "Headache attributed to an intracranial endovascular procedure" have been published, in 2004 and 2013.^1,2 Despite studies that have suggested that the former is not very practical, the ICHD-3 beta did not contain major changes. Moreover, so far no consensus exists regarding characteristics of headache after intracranial endovascular procedure. Thus, there is a need for sound suggestions to improve the ICHD-3 beta diagnostic criteria.

METHODS

Using a prospective design, we identified consecutive patients with unruptured intracranial aneurysms (UIAs) with neuroendovascular treatment from January 2014 to December 2014.

RESULTS

In total, 73 patients were enrolled, and 58 patients ultimately completed the 6-month follow-up. After the procedure, five of the 29 patients (17.2%) with pre-existing headache experienced marked worsening after the procedure, while seven of the 29 patients without prior headache developed new-onset headache post-procedurally. The headaches started within 24 hours, with a mean duration of 24-72 hours. The headaches were moderate to severe. The eligibility of these events to be considered headaches caused by neuroendovascular procedures according to the ICHD-3 beta diagnostic criteria for designation was far from ideal.

CONCLUSIONS

Most cases of markedly worsening headaches and new-onset headaches started within 24 hours and persisted longer than that specified in the ICHD-3 beta diagnostic criteria. Moreover, considering that some items are not very practical, the ICHD-3 beta diagnostic criteria should be revised in the light of recent literature reports.

Vasoactive Intestinal Polypeptide Evokes Only a Minimal Headache in Healthy Volunteers

The role of the parasympathetic nervous system in the pathogenesis of migraine is disputed. The headache-eliciting effect of the parasympathetic neurotransmitter, vasoactive intestinal polypeptide (VIP), and its effect on cerebral arteries and brain haemodynamics has not been systematically studied in man. We hypothesized that infusion of VIP might induce headache in healthy subjects and cause changes in cerebral haemodynamics. VIP (8 pmol/kg per min) or placebo (0.9± saline) was infused for 25 min into 12 healthy young volunteers in a crossover, double-blind design. Headache was scored on a verbal rating scale from 0 to 10, regional cerebral blood flow (rCBF) was measured with single-photon emission computed tomography and 133Xe inhalation and mean flow velocity in the middle cerebral artery (VmeanMCA) was measured with transcranial Doppler ultrasonography. The headache was very mild with a maximum score of 2 and described as a pressing or throbbing sensation. Five participants developed headache during VIP and one during placebo. During the infusion, a significant drop in VmeanMCA was seen for VIP compared with placebo ( P < 0.001), but the effect quickly waned and no difference was found when comparing the time between 30 and 120 min. In addition, no significant difference in the diameter of the MCA could be found during the infusion. No significant differences in rCBF ( P = 0.10) were found between VIP and placebo. A marked dilation of the superficial temporal artery was seen ( P = 0.04) after VIP in the first 30 min but no difference was found when comparing the time between 30 and 120 min. We found no difference in mean arterial blood pressure between VIP and placebo days but the heart rate increased significantly on a VIP day compared with a placebo day (AUC0–30min, P < 0.001). Plasma VIP was significantly higher on a VIP day compared with placebo (AUC0–80min, P < 0.001). These results show that VIP causes a decrease in VmeanMCA without affecting rCBF. In spite of a marked vasodilator effect in the extracranial vessels and increased plasma VIP, healthy subjects developed only a very mild headache.

Headache in subarachnoid hemorrhage and headache attributed to intracranial endovascular procedures

Headache is a critical problem in the emergency setting. In this paper we briefly review the epidemiological data regarding headache in Subarachnoid Hemorrhage (SAH), considering the role of headache as a warning symptom and the other clinical manifestation of SAH. We have also introduced a recent clinical entity, represented by headache associated to intracranial endovascular procedures (IEPs).

Headache, cerebral aneurysms, and the use of triptans and ergot derivatives

BACKGROUND

Uncertainty exists regarding the correlation between unruptured cerebral aneurysms and their role in headache etiology. It is also unclear whether surgical endovascular treatment may improve or worsen the headache, and if there are predictable factors for headache outcome such as pre-existing headache features, aneurysm characteristics, or other medical history. There is debate regarding safe treatment of migraine in patients with aneurysms, both before and after endovascular treatments. Particularly, there is hesitancy to use the triptans and ergot derivatives such as dihydroergotamine because of their vasoconstrictive effects and concern for adverse events related to the aneurysm such as aneurysmal instability and rupture.

OBJECTIVE

To review the literature regarding the anatomy, pathophysiology, and association between headache, untreated vs surgically treated aneurysms, and the use of triptans and ergot derivatives for migraine treatment in this setting.

CONCLUSION

Associations between some headaches and aneurysms may exist. Some chronic headaches may respond to surgical aneurysm repair while others may worsen. These associations are undefined by current literature because of variable results, study methods, and limited data. Prospective studies are needed which incorporate pre- and post-procedure headache character and diagnosis, aneurysm characteristics, type of aneurysm repair, associated risk factors for worsening post-procedure headache, and ultimately combining all of these data to better predict headache outcome following surgical aneurysm treatment. Lastly, the caution and avoidance of triptan and ergot derivative use for migraine in the setting of aneurysm is not supported by the current evidence, and much of this concern may be excessive and unwarranted, although more evidence confirming safety is needed.

[A causative role of vasodilation in migraine? Yes]

The role of vasodilatation in migraine pathophysiology is still debated with three hypotheses. The first is that vasodilatation of meningeal or intracranial arteries are the primary cause of pain. The second is that vasodilatation is secondary to neuronal activation, but can sustain or increase pain through sensitized perivascular nociceptors. The third is that vasodilatation is an epiphenomenon neither sufficient nor necessary for pain. We review in this part the arguments in favor of the old hypothesis that vasodilation is the primary cause of pain. Finally we show that there is a mild vasodilation during the attacks provoked by CGRP infusion.

A nitric oxide donor (nitroglycerin) triggers genuine migraine attacks

Supersensitivity to induction of headache and arterial dilatation by a donor of nitric oxide (nitroglycerin) has recently been demonstrated in migraine sufferers. The aims of the present study were to examine whether the nitric oxide donor nitroglycerin may induce a typical migraine attack, to exclude placebo-related effects and to describe the relation between middle cerebral artery dilatation and provoked migraine. Nitroglycerin (0.5 μg/kg/min for 20 min) or placebo was infused into 12 migraine patients in a double-blind cross-over trial. Blood velocity in the middle cerebral artery was measured with transcranial Doppler and characteristics of headache and accompanying symptoms were recorded frequently. Headache occurred during the nitroglycerin infusion as previously described but peak headache intensity did first occur 5.5 h after infusion. At this time the induced headaches in 8 of 10 completing patients fulfilled the diagnostic criteria for migraine without aura of the International Headache Society. Furthermore, all patients who normally had unilateral spontaneous migraine attacks also had unilateral headaches after nitroglycerin. Only one subject developed migraine after placebo (p < 0.03). The time pattern of headache and estimated middle cerebral artery dilatation corresponded well. The study therefore demonstrates that activation of the nitric oxide cGMP pathway may cause typical migraine attacks.

Temporary is not always benign: similarities and differences between transient ischemic attack and angina

The introduction of the tissue-based definition of transient ischemic attack (TIA), according to which TIA may be diagnosed only in the absence of an infarction on brain neuroimaging, prompts reflections about similarities and differences between TIA and angina. Both share transitory symptoms in the absence of tissue damage, whereas stroke and myocardial infarction are associated with tissue necrosis. Apart from this, TIA and angina are widely different with respect to pathophysiology, natural history, prognosis, and response to specific medical treatments. In general terms, it could be argued that TIA differs from angina as the brain differs from the heart in structure, physiology, metabolism, and performance. Most importantly, in TIA and angina, the reversible nature of symptoms cannot be assumed as a favorable prognostic indicator. In fact, reversibility of stable angina denotes a low-risk condition, whereas in TIA and unstable angina reversibility may suggest plaque instability and relevant risk of ischemic recurrences.

Pearls and pitfalls in human pharmacological models of migraine: 30 years' experience

In vitro studies have contributed to the characterization of receptors in cranial blood vessels and the identification of new possible anti-migraine agents. In vivo animal models enable the study of vascular responses, neurogenic inflammation, peptide release and genetic predisposition and thus have provided leads in the search for migraine mechanisms. All animal-based results must, however, be validated in human studies because so far no animal models can predict the efficacy of new therapies for migraine.

Given the nature of migraine attacks, fully reversible and treatable, the headache- or migraine-provoking property of naturally occurring signaling molecules can be tested in a human model. If such an endogenous substance can provoke migraine in human patients, then it is likely, although not certain, that blocking its effect will be effective in the treatment of acute migraine attacks.

To this end, a human in vivo model of experimental headache and migraine in humans has been developed. Human models of migraine offer unique possibilities to study mechanisms responsible for migraine and to explore the mechanisms of action of existing and future anti-migraine drugs. The human model has played an important role in translational migraine research leading to the identification of three new principally different targets in the treatment of acute migraine attacks and has been used to examine other endogenous signaling molecules as well as genetic susceptibility factors. New additions to the model, such as advanced neuroimaging, may lead to a better understanding of the complex events that constitute a migraine attack, and better and more targeted ways of intervention.

Spontaneous cervicocephalic arterial dissection with headache and neck pain as the only symptom

BACKGROUND AND OBJECTIVE

Cervicocephalic arterial dissection can cause both ischemic stroke and hemorrhagic stroke. However, spontaneous cervicocephalic arterial dissection presenting only with headache and neck pain has rarely been reported. The clinical features of patients with spontaneous cervicocephalic arterial dissection presenting only with headache and neck pain were investigated.

METHODS

The subjects were seven patients with spontaneous cervicocephalic arterial dissection with headache and neck pain alone who were admitted to our hospital during the past 3 years. The clinical features of these patients were investigated. The diagnosis of arterial dissection was based on the criteria of the Strategies Against Stroke Study for Young Adults in Japan.

RESULTS

The age of the patients (3 males, 4 females) ranged from 35 to 79 (mean, 51.0 ± 16.2) years. Six patients had vertebral artery dissection, one had internal carotid artery dissection, and one had an association of vertebral and internal carotid artery dissection. With the exception of one patient, the headache and neck pain were unilateral. All patients with vertebral artery dissection complained of posterior cervical or occipital pain. In the cases of internal carotid artery dissection, one patient complained of temporal pain, and one patient with co-existing vertebral artery dissection complained of posterior cervical pain. The mode of onset was acute in five patients, thunderclap in one, and gradual and progressive in one. The pain was severe in all cases. Five patients complained of continuous pain, while two had intermittent pain. The quality of the pain was described as throbbing by five patients and constrictive by two. The headache and neck pain persisted for 1 week or longer in six of the seven patients.

CONCLUSION

Cervicocephalic arterial dissection should be suspected when patients complain of intense unilateral posterior cervical and occipital pain or temporal pain.

Headache following intracranial neuroendovascular procedures

AIMS

Predicting who will develop post-procedure headache (PPH) following intracranial endovascular procedures (IEPs) would be clinically useful and potentially could assist in reducing the excessive diagnostic testing so often obtained in these patients. Although limited safety data exist, the use of triptans or dihydroergotamine (DHE) often raise concern when used with pre/post-coiled aneurysms. We sought to determine risk factors for PPH following IEP, to evaluate the utility of diagnostic testing in patients with post-coil acute headache (HA), and to record whether triptans and DHE have been used safely in this clinical setting.

METHODS

We conducted a retrospective chart review of adult patients undergoing IEPs. Bivariate analyses were conducted to compare patients who did and did not develop PPH.

RESULTS

We reviewed records pertaining to 372 patients, of whom 263 underwent intracranial coil embolizations, 21 acrylic glue embolizations, and 88 stent placements. PPH occurred in 72% of coil patients, 33% of glue patients, and 14% of stent patients. Significant risk factors for post-coil HA were female gender, any pre-coil HA history, smoking, and anxiety/depression. A pre-stent history of HA exceeding 1 year's duration, and smoking were risk factors for post-stent HA. A pre-glue history of HA exceeding 1 year was the only risk factor for post-glue HA. In the small subgroup available for study, treatment with triptans or DHE was not associated with adverse events in pre/post-coiled aneurysms. Diagnostic testing was low yield.

CONCLUSIONS

Occurrence of PPH was common after IEPs and especially so with coiling and in women, smokers, and those with anxiety/depression, and was often of longer duration than allowed by current International Classification of Headache Disorders-II criteria. The yield of diagnostic testing was low, and in a small subgroup treatment with triptans or DHE did not cause adverse events in pre/post-coiled aneurysms. Prospective studies are needed to confirm these findings.

The lack of peripheral pathology in migraine headache

This article reviews the baffling problem of the pathophysiology behind a peripheral genesis of migraine pain--or more particularly the baffling problem of its absence. I examine a number of pathophysiological states and the effector mechanisms for these states and find most of them very plausible and that they are all supported by abundant evidence. However, this evidence is mostly indirect; to date the occurrence of any of the presumed pathological states has not been convincingly demonstrated. Furthermore, there is little evidence of increased trigeminal sensory traffic into the central nervous system during a migraine attack. The article also examines a number of observations and experimental programs used to bolster a theory of peripheral pathology and suggests reasons why they may in fact not bolster it. I suggest that a pathology, if one exists, may be in the brain and even that it may not be a pathology at all. Migraine headache might just happen because of random noise in an exquisitely sensitive and complex network. The article suggests an experimental program to resolve these issues.

Lack of correlation between vasodilatation and pharmacologically induced immediate headache in healthy subjects

BACKGROUND

The causal relationship between experimental headache and vasodilatation has not been fully clarified. In the present study, we combined headache and vascular data from eight experimental studies and conducted detailed statistical analyses. Given that substances used in all these experiments were vasodilators we examined a possible correlation between headache scores and increases in arterial diameter.

METHODS

We identified nine studies and retrieved raw data in 89 healthy subjects (46 females, 43 males), mean age 27 years (range 18-59 years). The following variables were collected: maximal median headache intensity scores on a verbal rating scale (VRS) during immediate headache (0-120 minutes); the mean velocity of blood flow in the middle cerebral artery (V(meanMCA)); and the diameter of the frontal branch of the superficial temporal artery (STA) during the maximal median headache intensity.

RESULTS

The scatter plots show no relationship between maximal headache score and the relative changes in V(meanMCA) and diameter of the STA. The main analyses of covariance showed a significant effect only of heart rate on headache (p = .014). The interaction tests were insignificant for all variables.

CONCLUSIONS

The major outcome is a finding of no linear relationship between experimental immediate headache and dilatation of the MCA or STA.

Discrepancy between strong cephalic arterial dilatation and mild headache caused by prostaglandin D2 (PGD2)

Introduction: Prostaglandins (PGs) are involved in nociception and mast cell degranulation. Prostaglandin D2 (PGD2) is a vasodilatator released during mast cell degranulation. The headache-eliciting effect of PGD2 has not been studied in man.

Subjects and methods: Twelve healthy volunteers were randomly allocated to receive intravenous infusion of 384 ng/kg/min PGD2 over 25 min in a placebo-controlled, double-blind cross-over study. We recorded headache intensity and associated symptoms, velocity in the middle cerebral artery (VMCA) and diameter of the superficial temporal artery (STA) and radial artery (RA) using ultrasonography.

Results: In the period 0–14 h, 11 subjects reported headache on PGD2 compared to one subject on placebo ( P = 0.002). During the in-hospital phase (0–120 min), the area under the headache curve was larger on PGD2 compared to placebo ( P < 0.05). Median peak headache, 1 (0–1), occurred 10 min after start of PGD2 infusion. There was no difference in incidence of headache in the post-hospital phase between PGD2 ( n = 3) and placebo ( n = 1). There was a decrease in VMCA ( P < 0.001), increase in STA ( P < 0.001) and RA ( P < 0.006) diameter during PGD2 infusion compared to placebo. Peak decrease in VMCA was 28.3% after 10 min and peak increase in STA was 55.7% after 20 min on the PGD2 day. Conclusions: The present study shows that PGD2 is a very strong vasodilator of MCA, STA and RA, but causes only mild headache.

Headache attributed to carotid or vertebral artery pain

Headache or pain in the face or neck attributed to the carotid or vertebral artery was not recognized as a special type of pain until the concept of carotidynia occurred in the 1960s. Carotidynia has long been assumed as an entity until modern imaging techniques showed that pain localized in the carotid region could most often be related to injury of the artery or other symptomatic causes. These causes include headache due to arterial dissection, which has been described as a true pain originating from the vessel structure itself and which has also been attributed to a comorbidity of migraine and cervical artery dissection. Furthermore, headache starting after endarterectomy, carotid angioplasty headache, headache attributed to intracranial endovascular procedures, and angiography headache have been listed among the headache and pain syndromes due to changes of the cervical arteries. It is still not clarified whether carotidynia is a specific idiopathic disease or whether the previous descriptions of carotidynia just resembled symptomatic causes of carotid pain.

Delayed Migraine-Like Headache in Healthy Volunteers After a Combination of Acetazolamide and Glyceryl Trinitrate

Glyceryl trinitrate (GTN) is a pro-drug dissociating nitric oxide throughout the body. It dilates cephalic arteries without increasing cerebral blood flow (CBF). GTN induces headache in healthy volunteers and migraine attacks in migraineurs. Acetazolamide (Az) increases CBF but does not dilate cerebral arteries. The hypothesis tested here was that Az, by dilating cerebral arterioles but not arteries and thereby decreasing pulsatile stretching of the wall of the large arteries and their perivascular sensory nerves, would reduce or prevent the GTN-induced headache We tested this hypothesis in 14 healthy volunteers. In a randomized, double-blind, cross-over study, they were pretreated with Az or placebo followed on both study days by a GTN infusion of 0.5 μg kg-1 min-1 for 20 min. Headache was scored on a verbal rating scale and a headache diary was kept for 12 h. Mean blood velocity of the middle cerebral artery was measured (transcranial Doppler). Our hypothesis was disproved, as Az did not decrease GTN-induced headache. Unexpectedly but interestingly, GTN combined with Az induced more delayed headache than GTN alone. Furthermore, a migraine-like headache was observed in three volunteers, who did not develop migraine after GTN alone. The fact that a suitable pharmacological intervention may trigger migraine in individuals with no prior migraine may suggest that the ability to develop migraine without aura is a quantitative genetic trait.

Origin of pain in migraine: evidence for peripheral sensitisation

Migraine is the most common neurological disorder, and much has been learned about its mechanisms in recent years. However, the origin of painful impulses in the trigeminal nerve is still uncertain. Despite the attention paid recently to the role of central sensitisation in migraine pathophysiology, in our view, neuronal hyperexcitability depends on activation of peripheral nociceptors. Although the onset of a migraine attack might take place in deep-brain structures, some evidence indicates that the headache phase depends on nociceptive input from perivascular sensory nerve terminals. The input from arteries is probably more important than the input from veins. Several studies provide evidence for input from extracranial, dural, and pial arteries but, likewise, there is also evidence against all three of these locations. On balance, afferents are most probably excited in all three territories or the importance of individual territories varies from patient to patient. We suggest that migraine can be explained to patients as a disorder of the brain, and that the headache originates in the sensory fibres that convey pain signals from intracranial and extracranial blood vessels.

Prostaglandin I2 (epoprostenol) triggers migraine-like attacks in migraineurs

Prostacyclin [prostaglandin I2 (PGI2)] activates and sensitizes meningeal sensory afferents. In healthy subjects PGI2 triggers headache in healthy subjects. However, the migraine-eliciting effect of PGI2 has not been systematically studied in patients with migraine. We hypothesized that intravenous infusion of the stable prostacyclin analogue epoprostenol would trigger migraine-like attacks in migraineurs. We infused 10 ng kg−1 min−1 PGI2 or placebo over 25 min in 12 migraineurs without aura in a controlled, double-blind, cross-over study and recorded headache intensity and associated symptons, velocity in the middle cerebral artery (VMCA) and diameter in the superficial temporal artery. In the period 0–14 h, 12 subjects reported headache on PGI2 day compared with three subjects on placebo day ( P = 0.004), and six subjects fulfilled the criteria for an experimentally induced migraine-like attack compared with two subjects on placebo ( P = 0.219). During infusion and post-infusion phases the AUC under the headache curve on PGI2 was significantly larger than on placebo ( P < 0.05). There was a significant VMCA decrease ( P = 0.015) and superficial temporal artery diameter increase ( P < 0.001) on PGI2 compared with placebo. In conclusion, PGI2 may trigger a migraine-like attack in migraine sufferers. We suggest sensitization of perivascular nociceptors and arterial dilation as the mode of action of PGI2-induced headache and migraine-like attacks.

Examining the essence of migraine--is it the blood vessel or the brain? A debate

A debate is presented that examines whether it is the blood vessel or the brain that determines the essence of migraine.

Familial hemiplegic migraine type 1 shows no hypersensitivity to nitric oxide

Familial hemiplegic migraine type 1 (FHM-1) is a dominantly inherited subtype of migraine with aura and transient hemiplegia associated with mutations in the CACNA1A gene. FHM-1 shares many phenotypical similarities with common types of migraine, indicating common neurobiological pathways. Experimental studies have established that activation of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway plays a crucial role in migraine pathophysiology. Therefore, we tested the hypothesis that CACNA1A mutations in patients with FHM-1 are associated with hypersensitivity to NO-cGMP pathway. We included eight FHM-1 patients with R583Q and C1369Y mutations and nine healthy controls, who received intravenous infusions of 0.5 microg kg(-1) min(-1) glyceryl trinitrate (GTN) over 20 min. We recorded: headache intensity on a verbal rating scale; mean flow velocity in the middle cerebral artery (V(meanMCA)) by transcranial Doppler; diameter of the superficial temporal artery (STA) by Dermascan. One patient reported migraine without aura 5 h after start of the GTN infusion. No aura was reported. The AUC(headache) in the immediate phase was more pronounced in patients than in controls (P = 0.01). In the 14 h following GTN infusion, there was no difference in the AUC(headache) between patients and controls (P = 0.17). We found no difference in the AUC(VmeanMCA) (P = 0.12) or AUC(STA) (P = 0.71) between FHM-1 patients and controls. None of the control persons reported migraine-like headache. FHM-1 patients do not show hypersensitivity of the NO-cGMP pathway, as characteristically seen in migraine patients with and without aura. This indicates that the pathophysiological pathways underlying migraine headache in FHM-1 may be different from the common types of migraine.

Headaches during angiography and endovascular procedures

BACKGROUND

The occurrence of headaches during cerebral angiography or endovascular procedures is an ill-defined issue, as limited information is available to define its frequency, risk factors, pathogenesis and implications for future pain management.

PURPOSE

To determine the frequency of headaches during endovascular procedures (HdEVP) and to define their characteristics and risk factors for their occurrence.

METHODS

Prospective cross-sectional observational study of adult patients undertaking cerebral angiography or endovascular procedures, recording HdEVP clinical features, previous headache history and procedural variables.

RESULTS

One hundred and twenty two procedures were evaluated. HdEVP occurred in 13 patients, both in diagnostic and therapeutic procedures. Pain was described as brief, stabbing or localized pressure of mild to moderate intensity, felt ipsilaterally to the manipulated vessel. Its occurrence was associated with therapeutic interventions (p = 0.007), female gender (p = 0.015) and previous history of more than 4 headache episodes per month (p = 0.018).

CONCLUSION

HdEVP is an uncommon brief headache that should be further evaluated in the future. Its pathogenesis is probably related to mechanical vessel distension, which activates the trigeminovascular nociceptive system in susceptible individuals.

The Discovery of a New Drug Class for the Acute Treatment of Migraine

The history of the scientific ideas and events that led to the discovery of sumatriptan is outlined with personal reminiscences about individuals who influenced the approach. The development of sumatriptan revolutionized the acute treatment of migraine and led to the availability of a number of other triptans. The anti-migraine effects of all the triptans are mediated via 5-HT(1B), and possibly 5-HT(1D) receptors, which transduce their effects via G; proteins. This suggests that agonists at other G(i) protein-coupled receptor types appropriately located (eg, somatostatin sst(2), adenosine A(1)) should be examined for their effects on the trigeminovascular system, Studies on such receptor targets may provide insight into a novel approach towards the design of new anti-migraine drugs.

The headache-inducing effect of cilostazol in human volunteers

We have previously shown that nitric oxide (NO) and cyclic guanosine monophosphate (GMP) may cause headache and migraine. However, not all findings in previous studies can be explained by an activation of the NO-cGMP pathway. Calcitonin gene-related peptide (CGRP) causes headache and migraine in migraine patients, but CGRP receptor activation causes an increase in cyclic adenosine monophosphate (cAMP). In order to investigate the role of cAMP in vascular headache pathogenesis, we studied the effect of cilostazol, an inhibitor of cAMP degradation, in our human experimental headache model. Twelve healthy volunteers were included in a double-blind, randomized, crossover study. Placebo or cilostazol (200 mg p.o.) was administered on two separate study days. Headache was scored on a verbal rating scale (0-10) and mechanical pain thresholds were measured with von Frey hairs. The median peak headache score 0-16 h postdose was 0 (range 0-2) after placebo and 3.5 (range 0-7) after cilostazol (P = 0.003). The median headache curve peaked at 6-9 h postdose. The headaches induced were usually bilateral and pulsating. Nausea occurred in two volunteers, photo- and phonophobia were not seen. Two volunteers had a headache that fulfilled International Headache Society criteria for migraine without aura after cilostazol. No change in mechanical pain thresholds in the forehead was seen (P = 0.25). The headache after cilostazol was equal to or more severe than headache induced by glyceryl trinitrate in previous experiments. The present study thus indicates that increased levels of cAMP may play a role in headache and migraine pathogenesis.

Migraine: a review and future directions for treatment

Migraine is a chronic, neurological disorder generally manifesting itself in attacks with severe headache, nausea and an increased reactivity to sensory stimuli. A low migraine threshold is set by genetic factors, although the phenotype also modulates the manifestations. The 1-year prevalence is approximately 13% and is higher among women. Patients usually experience neuropsychological dysfunction, and sometimes also reversible focal neurological symptoms. The trajectories of the characteristic symptoms of acute migraine usually follow a similar time course, indicating a reciprocal underlying mechanism. A central nervous system hyperexcitability has been demonstrated in neurophysiological studies. The dibilitating effects of migraine are not confined to the attacks per se. Many individuals do not recover completely between the attacks and most report a negative impact on the most important life domains, and an interest in testing other treatments. Young persons have a higher frequency of attacks. Acute treatment should routinely be initiated with an analgesic plus a prokinetic anti-emetic. Triptans must not be provided early during the attack to ensure their efficacy. The natural course of attacks is commonly only temporarily altered by acute treatment. Non-pharmacological treatment and drugs may be equally viable in prophylaxis for migraine. In more complicated cases, conjoint therapy should be considered. New strategies to improve adherence with existing therapeutic regimens might yield greater benefits than will new pharmacological agents.

Hypothalamic activation after stimulation of the superior sagittal sinus in the cat: a Fos study

Clinical observations, particularly of the premonitory phase of migraine, suggest the involvement of the hypothalamus in the earliest phases of an attack. Stimulation of the superior sagittal sinus (SSS) in humans produces head pain and permits study of the activated trigeminovascular system in experimental settings. The distribution of neurons expressing the protein product (Fos) of the c-fos immediate early gene was examined in the hypothalamus of anaesthetised (alpha-chloralose) cats. Animals were studied after either 2-h stimulation of the SSS or sham stimulation. Fos protein was detected using immunohistochemistry, and positive neurons were plotted onto standardised templates and counted by a blinded observer. In response to electrical stimulation of the superior sagittal sinus, we found significant activation of the supra-optic nucleus (SON) rising from 3 (0-13) (median, 95% confidence interval) to 53 (31-78; P = 0.005) fos-positive cells. In the posterior hypothalamic area (Hp), fos-positive cells rose from 4 (0-14) to 35 (17-45; P = 0.015) Taken together with other physiological studies, the data are consistent with a role for hypothalamic structures in the modulation of trigeminovascular nociceptive afferent information, and thus for a role in headache.

Effect of Endovascular Treatment on Headaches in Patients With Unruptured Intracranial Aneurysms

BACKGROUND

Patients with unruptured intracranial aneurysms often present with headaches.

OBJECTIVE

To determine the effect of endovascular treatment on the character and frequency of headaches in patients with unruptured intracranial aneurysms.

METHODS

We reviewed the medical records of all patients who underwent endovascular treatment for unruptured intracranial aneurysms within a 9.5-year period. These patients were mailed a standard questionnaire in which they were asked about the frequency and character of any headache experienced before or after (or both) endovascular treatment. They were also asked to grade improvement or worsening of headaches after the procedure as mild (activities of daily living were not affected), moderate (activities of daily living were affected), or significant (the change resulted in an ability to perform new activities of daily living or an inability to perform previous activities of daily living).

RESULTS

Forty-seven patients with unruptured aneurysms who underwent Guglielmi detachable coil embolization responded to the questionnaire. Of these, 32 patients (mean age, 52.7 years [SD, 13.4]; 22 were women) had experienced headaches before the procedure. Nineteen patients (59%) reported improvement in severity of headaches after embolization. Improvement was graded as significant by 7 patients, moderate by 8, and mild by 4. Two patients (6%) reported worsening severity of headaches graded as moderate. Five of 15 patients without headaches before embolization reported onset of mild (n = 4) or severe (n = 1) headaches after treatment.

CONCLUSION

Guglielmi detachable coil embolization of unruptured intracranial aneurysms was associated with reduction in severity of headaches in the majority of patients who had experienced preprocedural headaches.

Headaches in cervical artery dissections

Internal carotid artery (ICA) and vertebral artery (VA) dissections are among the common causes of stroke in middle-aged and young adults. The spectrum of clinical presentations of these dissections is broad. Many patients, especially those with ICA dissections, may never develop a stroke.

Headache as a surrogate marker of the molecular mechanisms implicated in progressing stroke

The mechanism for headache in patients with acute ischaemic stroke are not completely understood. We analysed the relationship between headache and the early worsening of neurological symptoms in patients with acute ischaemic stroke, and we studied the possible biochemical mechanisms implicated. Headache at the onset of ischaemic stroke predicted progression with a sensitivity, specificity, and positive predictive value of 56%, 99%, and 98%, respectively. CSF concentrations of glutamate, Interleukin-6, and NO-m were significantly greater in patients with progressing stroke than in patients with nonprogressing stroke, and these biochemical markers were also significantly higher in patients with headache than in those without headache. Results of this study suggest that headache at the onset of ischaemic stroke is an independent predictor of neurological worsening and we hypothesize that headache might be a surrogate marker of the molecular mechanisms involved in neurological worsening after acute stroke.

Is the 5-HT(7) receptor involved in the pathogenesis and prophylactic treatment of migraine?

The mechanisms underlying the pathogenesis of migraine and their possible association with serotonin (5-hydroxytryptamine; 5-HT) have not yet been elucidated. One of the major obstacles in achieving this goal is the lack of information on the mechanisms by which the monoamine could possibly trigger and/or modulate the basic pathophysiological features of the condition, that is, cranial vasodilatation and neurogenic inflammation. This information should provide a useful theoretical framework to insight the nature of the postulated fundamental triggering mechanism in the brain that ultimately results in head pain. Novel avenues for research and drug development may be envisaged upon the recent observations showing that 5-HT is actually able to produce vasodilatation of intra- and extra-cranial blood vessels through a mechanism pharmacologically resembling the 5-HT(7) receptor type, and that the messenger RNA (mRNA) encoding for this receptor is highly expressed in cranial vessels. Other lines of evidence have suggested that the 5-HT(7) receptor may play an excitatory role in neuronal systems and that it may be involved in hyperalgesic pain and neurogenic inflammation. On the basis of these observations, it is proposed that the 5-HT(7) receptor may well represent a link between the abnormal phenomena of 5-HT processing and neurotransmission that are observed in migraine patients, and the vascular and neurogenic alterations that account for migraine headache. This view is supported by the fact that most of the migraine prophylactic 5-HT receptor antagonists display relatively high affinity for the 5-HT(7) receptor, which significantly correlates with their pharmaceutically active oral doses.