Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendations

Does Calcified Neurocysticercosis Affect Migraine Characteristics and Treatment Responsiveness? A Case-Control Study

Recently, inflammation and free-radical release has been described in the surrounding brain parenchyma of seemingly inert calcified lesions of neurocysticercosis. These free radicals can induce migraine by stimulating calcitonin gene-related peptide release. This stipulated mechanism led us to hypothesize that calcified neurocysticercosis may increase migraine severity. This case-control study included patients (migraine with calcified neurocysticercosis) and control subjects (migraine without calcified neurocysticercosis) in a 1:1 ratio. Headache frequency, visual analog scale (VAS) score, and Migraine Disability Assessment (MIDAS) score were assessed at baseline and at the end of 3 months. To compare treatment responsiveness between patients and control subjects, we treated both groups identically so that difference in treatment would not confound the results. Each group comprised 78 patients. Baseline headache frequency (11.3 ± 3.3 versus 7.9 ± 3.4), VAS score (7.5 ± 1.1 versus 6.0 ± 1.2), and MIDAS score (15 ± 7.6 versus 9.6 ± 4.5) were significantly greater in patients than control subjects. Interestingly, the change from baseline to the end of 3 months in headache frequency (6.0 ± 1.7 versus 2.8 ± 1.4), VAS score (2.6 ± 0.02 versus 1.4 ± 0.01), and MIDAS score (8.3 ± 5.0 versus 3.6 ± 2.0) were significantly greater in patients than control subjects. Our study emphasizes that calcified lesions of neurocysticercosis are not inert, and cause an increase in the frequency and severity of migraine attacks. Interestingly, these patients also showed a better response to treatment with amitriptyline, possibly resulting from its anti-inflammatory action. Further studies are warranted to explore possible inflammatory mechanisms in calcified neurocysticercosis, which influences migraine physiology.

Brain Excitability in Tension-Type Headache: a Separate Entity from Migraine?

PURPOSE OF REVIEW

Tension-type headache is often regarded as the "normal" headache due to its high prevalence and mild disability in contrast with migraine. Clinically, both headaches are common comorbidities to each other. To date there has been many studies linked migraine to a brain excitability disorder. This review summarized earlier studies on brain excitability of TTH and discuss if TTH is a separate clinical entity from migraine as suggested by the diagnostic criteria.

RECENT FINDINGS

A recent magnetoencephalographic study from our group enrolled patients with "strict-criteria" TTH (i.e., absence of any migraine characteristics and associated symptoms) to compare the somatosensory excitability with patients with migraine and controls. This study provided evidence that TTH and migraine differ in excitability profiles and the measurement of preactivation excitability was able to discriminate TTH from migraine. Earlier studies on brain excitability of TTH yielded negative findings or a common change shared with migraine. Future studies using strict diagnostic criteria to avoid the unwanted interference from migraine comorbidity may help decipher the "true" pathophysiology of TTH, which may pave the way to a TTH-specific brain signature and treatment.

Factors Associated with Incidental Neuroimaging Abnormalities in New Primary Headache Patients

Background and Purpose

Deciding whether or not to perform neuroimaging in primary headache is a dilemma for headache physicians. The aim of this study was to identify clinical predictors of incidental neuroimaging abnormalities in new patients with primary headache disorders.

Methods

This cross-sectional study was based on a prospective multicenter headache registry, and it classified 1,627 consecutive first-visit headache patients according to the third edition (beta version) of the International Classification of Headache Disorders (ICHD-3β). Primary headache patients who underwent neuroimaging were finally enrolled in the analysis. Serious intracranial pathology was defined as serious neuroimaging abnormalities with a high degree of medical urgency. Univariable and multivariable logistic regression analyses were conducted to identify factors associated with incidental neuroimaging abnormalities.

Results

Neuroimaging abnormalities were present in 170 (18.3%) of 927 eligible patients. In multivariable analysis, age ≥40 years [multivariable-adjusted odds ratio (aOR)=3.37, 95% CI=2.07–6.83], male sex (aOR=1.61, 95% CI=1.12–2.32), and age ≥50 years at headache onset (aOR=1.86, 95% CI=1.24–2.78) were associated with neuroimaging abnormalities. In univariable analyses, age ≥40 years was the only independent variable associated with serious neuroimaging abnormalities (OR=3.37, 95% CI=1.17–9.66), which were found in 34 patients (3.6%). These associations did not change after further adjustment for neuroimaging modality.

Conclusions

Incidental neuroimaging abnormalities were common and varied in a primary headache diagnosis. A small proportion of the patients incidentally had serious neuroimaging abnormalities, and they were predicted by age ≥40 years. These findings can be used to guide the performing of neuroimaging in primary headache disorders.

Advanced Imaging in the Evaluation of Migraine Headaches

The use of advanced imaging in routine diagnostic practice appears to provide only limited value in patients with migraine who have not experienced recent changes in headache characteristics or symptoms. However, advanced imaging may have potential for studying the biological manifestations and pathophysiology of migraine headaches. Migraine with aura appears to have characteristic spatiotemporal changes in structural anatomy, function, hemodynamics, metabolism, and biochemistry, whereas migraine without aura produces more subtle and complex changes. Large, controlled, multicenter imaging-based observational trials are needed to confirm the anecdotal evidence in the literature and test the scientific hypotheses thought to underscore migraine pathophysiology.

An update on EEG in migraine

Introduction: In the past few years, brain functional analysis has provided scientific evidence supporting the neuronal basis of migraine. The role of electroencephalography (EEG) in detecting subtle dysfunctions in sensory temporal processing has been fully re-evaluated, thanks to advances in methods of quantitative analysis. However, the diagnostic value of EEG in migraine is very low, and migraine diagnosis is completely based on clinical criteria, while the utility of EEG in migraine pathophysiology has only been confirmed in more recent applications. Areas covered: The present review focuses on the few situations in which EEG may provide diagnostic utility, and on the numerous and intriguing applications of novel analysis, based on time-related changes in neuronal network oscillations and functional connectivity. Expert opinion: Although routine EEG is not particularly useful for the clinical assessment of migraine, novel methods of analysis, mostly based on functional connectivity, could improve knowledge of the migraine brain. The application is worthy of promotion and improvement in support of neuroimaging data to shed light on migraine mechanisms and support the rationale for therapeutic approaches.

Unnecessary Neuroimaging for Patients With Primary Headaches

Background - Headache may be due to either a primary or secondary disorder, and neuroimaging assessments can play an important role when differentiating between these types of headache. Although many studies have reported no significant differences between primary headache patients and the general population in terms of abnormal neuroimaging findings, others have shown that neuroimaging may be employed to rule out secondary causes of headache that could impact morbidity and mortality. This issue remains under debate. Thus, the present study compared the neuroimaging findings of headache patients and healthy controls. Methods - This study recruited 1070 healthy controls and 1070 primary headache patients from the Chinese People's Liberation Army General Hospital. The primary headache patients were diagnosed by computerized clinical decision support systems, and re-diagnosed by a specialist. All participants were assessed with either computed tomography or magnetic resonance imaging (MRI) scans. The neuroimaging findings were classified as significant abnormalities, non-significant abnormalities, or normal. Results - All the significant abnormalities were found using MRI scans. Significant abnormalities were identified in 4 primary headache patients (0.58%) and 5 healthy controls (0.73%); the rate of significant abnormalities was not significant different between both groups (P > .05). Conclusions - The present study found that neuroimaging was unnecessary for the primary headache patients.

Insights into radiographic investigations for headaches in general practice

BACKGROUND/OBJECTIVE

Headaches present commonly in general practice, and doctors face uncertainties and pressures in dealing with them. This study identifies key characteristics of headaches investigated through head imaging, in the hope of strengthening existing guidelines.

METHOD

A 7-year retrospective analysis of head imaging scans ordered for investigating headaches among patients aged ≥18 in an Australian general practice setting.

RESULTS

A total of 109 of the 517 (21.1%) patients required head imaging, although 14 (2.7%) of these had repeat scans. Three-quarters were females, and most of the headaches were recurrent (56.9%), severe (62.4%) or had associated red flags (78.0%). Computed tomography (CT) and magnetic resonance imaging (MRI) were the only scans adopted (4:1 and 1:1 for first and repeat scans, respectively). Twelve (11.0%) scans had findings likely to explain the headaches after the initial scans, with no difference in findings between diagnoses from CTs and MRIs (P = 0.41). Repeat scans offered no additional benefits, and roughly one in three patients were referred to third-party carers (mostly neurologists). Females had more recurrent headaches (OR = 2.63; CI = 1.09-6.35; P = 0.03). Patients with psycho-morbidities were less likely to have scan findings that explained their headaches (OR = 0.22; CI = 0.06-0.88; P = 0.03), and, though not quite significant, were also more likely to undergo imaging (OR = 1.47; CI 0.96-2.27; P = 0.08).

CONCLUSION

Significant intracranial findings were uncommon following imaging for headaches, and MRIs offer no advantages over CTs. Repeating head scans within 5 years offers no clear benefits. Psycho-morbidities should be considered when deciding the imaging needs, given the lesser chance of findings. Larger studies will help validate these findings.

Functional Neuroimaging Biomarkers in Migraine: Diagnostic, Prognostic and Therapeutic Implications

BACKGROUND

In current migraine clinical practice, conventional neuroimaging examinations are often sought to exclude possible causes of secondary headaches or migraineassociated disorders. Contrariwise, although advanced Magnetic Resonance Imaging (MRI) has improved tremendously our understanding of human brain processes in migraine patients, to the state of the art they have not superseded the conventional neuroimaging techniques in the migraine clinical setting.

METHODS

A comprehensive review was conducted of PubMed citations by entering the keyword "marker" and/or "biomarker" combined with "migraine" and/or "headache". Other keywords included "imaging" or "neuroimaging", "structural" or "functional". The only restriction was English-language publication. The abstracts of all articles meeting these criteria were reviewed, and the full text was retrieved and examined for relevant references.

RESULTS

Several authors tried to identify imaging biomarkers able to identify different migraine phenotypes or, even better, to follow-up the same migraine patients during the course of the disease, to predict the evolution into more severe phenotypes and, finally, the response to specific treatment.

CONCLUSION

The identification of diagnostic, prognostic and therapeutic advanced neuroimaging biomarkers in the migraine clinical setting, in order to approach to patients in a more and more rational and "tailored" way, is extremely intriguing and futuristic. Unfortunately, reliable and robust neuroimaging biomarkers are still lacking for migraine, probably due to both not completely understood pathogenesis and clinical and neuroimaging heterogeneity. Although further longitudinal advanced neuroimaging studies, aimed to identify effective neuroimaging biomarkers, are needed, this review aims to collect the main and most recent works on this topic.

Neuroimaging utilization and findings in headache outpatients: Significance of red and yellow flags

Background

Neuroimaging for headache commonly exceeds published guideline recommendations and may be overutilized.

Methods

We conducted a retrospective cross-sectional study of all outpatient community patients at Mayo Clinic Rochester who underwent a neuroimaging study for a headache indication in 2015. We assessed the neuroimaging utilization pattern, clinical application of red flags, and concordance with neuroimaging guidelines.

Results

We identified 190 outpatients who underwent 304 neuroimaging studies for headache. The median age was 46.5 years (range 18–91 years), 65% were female, and most reported no prior history of headache (n = 97, 51%). A minority of patients had prior brain imaging studies (n = 44, 23%) and neurological consultations for headache (n = 29, 15%). Few studies were ordered after consultation with a neurologist (n = 14, 7%). Seventy-seven percent of patients were documented to have a “red flag” justifying the imaging study. Abnormal neuroimaging findings were found in 3.1% of patients with warning flags (5/161); carotid dissection (n = 3) and reversible cerebral vasoconstrictive syndrome (n = 2). An estimated 35% of patients were imaged against guidelines.

Conclusions

The prevalence of serious causes of headache in a community practice was low despite the presence of a documented red flag symptom. Inadequate understanding or application of red flags may be contributing to recommendations to image patients against current guidelines. Interventions to reduce unnecessary neuroimaging of patients with headache need to be designed and implemented.

Cognitive and Behavioural Effects of Migraine in Childhood and Adolescence

Since cognitive and behavioural characteristics of paediatric migraineurs have yet to be adequately defined, in this study we assessed the effect of migraine on the interictal functioning of children and adolescents by comparing the performance of two patient groups, 17 migraineurs with aura (MA) and 31 without aura (MoA) and by correlating the duration of the disorder, the frequency of attacks and interictal period with neuropsychological and behavioural findings. Both patient groups had cognitive performance within normal range except for a significant delay in the reaction time (RT) task. Both MA and MoA revealed a behavioural phenotype characterized by internalizing problems on Child Behaviour Check List (CBCL) scales. Slower RT to simple visual stimuli may be an early sign of a subclinical neuropsychological dysfunction, significantly correlated with the frequency of headache attacks and interictal period. The lack of a control group and other methodological limitations, such as patient selection bias and unadjusted P-value for multiple testing, make it difficult to give this finding a clearcut meaning. Further studies are needed on larger samples compared with a control group.

Headache neuroimaging: Routine testing when guidelines recommend against them

AIMS

The aim of this article is to determine the patient-level factors associated with headache neuroimaging in outpatient practice.

METHODS

Using data from the 2007-2010 National Ambulatory Medical Care Surveys (NAMCS), we estimated headache neuroimaging utilization (cross-sectional). Multivariable logistic regression was used to explore associations between patient-level factors and neuroimaging utilization. A Markov model with Monte Carlo simulation was used to estimate neuroimaging utilization over time at the individual patient level.

RESULTS

Migraine diagnoses (OR = 0.6, 95% CI 0.4-0.9) and chronic headaches (routine, chronic OR = 0.3, 95% CI 0.2-0.6; flare-up, chronic OR = 0.5, 95% CI 0.3-0.96) were associated with lower utilization, but even in these populations neuroimaging was ordered frequently. Red flags for intracranial pathology did not increase use of neuroimaging studies (OR = 1.4, 95% CI 0.95-2.2). Neurologist visits (OR = 1.7, 95% CI 0.99-2.9) and first visits to a practice (OR = 3.2, 95% CI 1.4-7.4) were associated with increased imaging. A patient with new migraine headaches has a 39% (95% CI 24-54%) chance of receiving a neuroimaging study after five years and a patient with a flare-up of chronic headaches has a 51% (32-68%) chance.

CONCLUSIONS

Neuroimaging is routinely ordered in outpatient headache patients including populations where guidelines specifically recommend against their use (migraines, chronic headaches, no red flags).

Primary headache disorders

Primary headache disorders include migraine, tension-type headaches, and the trigeminal autonomic cephalgias (TACs). "Primary" refers to a lack of clear underlying causative pathology, trauma, or systemic disease. The TACs include cluster headache, paroxysmal hemicrania, and short-lasting neuralgiform headache attacks with conjunctival injection and tearing; hemicrania continua, although classified separately by the International Headache Society, shares many features of both migraine and the TACs. This article describes the features and treatment of these disorders.

Psychophysiological mechanisms underlying spatial attention in children with primary headache

OBJECTIVE

Neurophysiological studies to evaluate spatial attention in children with primary headache are lacking. Tactile spatial attention modulates the N140 somatosensory evoked potential (SEP) amplitude. The aims of the study are: (1) to investigate the effect of spatial attention on the N140 amplitude in children with migraine and tension-type headache (TTH) and in healthy children, and (2) to correlate the neurophysiological results with a neuropsychological test for spatial attention.

METHODS

We studied 16 patients with migraine without aura (MoA), 12 TTH children and 10 healthy subjects. "Deux Barrage" test for spatial attention was administered. SEPs were recorded in a neutral condition (NC) and in a spatial attention condition (SAC).

RESULTS

No significant differences in neuropsychological measures were found between MoA, TTH and healthy subjects. The N140 amplitude increase during SAC, as compared to NC, was significantly higher in patients than in healthy controls. Migraineurs showed a positive correlation between the N140 amplitude increase during SAC and their neuropsychological performance.

CONCLUSIONS

Although spatial attention performances in children with headache are as good as in controls, the N140 amplitude increase during SAC in headache patients suggests that the psychophysiological mechanisms subtending spatial attention are different from those in healthy children.

Why do GPs with a special interest in headache investigate headache presentations with neuroradiology and what do they find?

The general practitioner with a special interest in headache offers an important contribution to the management of headache in primary care where the majority of presentations take place. A number of guidelines have been developed for neuroradiological investigation of headache, but their clinical utility and relevance is not known. Fourteen general practitioners with a special interest in headache recorded consecutive headache consultations over a 3-month period, whether patients were investigated with neuroradiology and if so the reason for investigation and outcome. Reason for investigation was compared to the guidelines published for the use in primary care. 895 patients were seen, of whom 270 (30.1%) were investigated. 47% of indications were outside the guidance framework used, the most common reason for investigation being reassurance. Of those investigated, 5.6% showed positive findings but only 1.9% of findings were felt to be of clinical significance. General practitioners with a special interest investigated with neuroradiology a greater level than general practitioners, but less than neurologists. However, yields of significant findings are broadly comparative across all groups. This report confirms other studies that suggest that even when there is a high level of clinical suspicion, yields of significant findings are very low.

Pressure pain sensitivity of the scalp in patients with nummular headache: a cartographic study

Nummular headache (NH) is characterized by focal pain fixed within a small round or elliptical area of the head surface. Sensory dysfunction is apparently restricted to the symptomatic area, but a thorough analysis of cranial pain sensitivity has not been performed. Pressure pain sensitivity maps were constructed for 21 patients with NH and 21 matched healthy controls. In each subject pressure pain thresholds (PPT) were measured on 21 points distributed over the scalp. In each patient PPT were also measured in the symptomatic area and at a non-symptomatic symmetrical point. In both groups an anterior to posterior gradient was found on each side, with no significant differences of PPT measurements between sides or groups. In patients with NH, only the symptomatic area showed a local decrease of PPT (significant in comparison with the non-symptomatic symmetrical point, P < 0.001). These findings further support that NH is a non-generalized disorder with a peripheral source.

Neurophysiological tests and neuroimaging procedures in non-acute headache (2nd edition)

BACKGROUND AND PURPOSE

A large number of instrumental investigations are used in patients with non-acute headache in both research and clinical fields. Although the literature has shown that most of these tools contributed greatly to increasing understanding of the pathogenesis of primary headache, they are of little or no value in the clinical setting.

METHODS

This paper provides an update of the 2004 EFNS guidelines and recommendations for the use of neurophysiological tools and neuroimaging procedures in non-acute headache (first edition). Even though the period since the publication of the first edition has seen an increase in the number of published papers dealing with this topic, the updated guidelines contain only minimal changes in the levels of evidence and grades of recommendation.

RESULTS

(i) Interictal EEG is not routinely indicated in the diagnostic evaluation of patients with headache. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic or basilar migraine. (ii) Recording evoked potentials is not recommended for the diagnosis of headache disorders. (iii) There is no evidence warranting recommendation of reflex responses or autonomic tests for the routine clinical examination of patients with headache. (iv) Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pain threshold measurements and EMG are not recommended as clinical diagnostic tests. (v) In adult and pediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological symptoms or signs, the routine use of neuroimaging is not warranted. In patients with trigeminal autonomic cephalalgia, neuroimaging should be carefully considered and may necessitate additional scanning of intracranial/cervical vasculature and/or the sellar/orbital/(para)nasal region. In patients with atypical headache patterns, a history of seizures and/or focal neurological symptoms or signs, MRI may be indicated. (vi) If attacks can be fully accounted for by the standard headache classification (IHS), a PET or SPECT scan will normally be of no further diagnostic value. Nuclear medical examinations of the cerebral circulation and metabolism can be carried out in subgroups of patients with headache for the diagnosis and evaluation of complications, when patients experience unusually severe attacks or when the quality or severity of attacks has changed. (vii) Transcranial Doppler examination is not helpful in headache diagnosis.

CONCLUSION

Although many of the examinations described in the present guidelines are of little or no value in the clinical setting, most of the tools, including thermal pain thresholds and transcranial magnetic stimulation, have considerable potential for differential diagnostic evaluation as well as for the further exploration of headache pathophysiology and the effects of pharmacological treatment.

Neuroimaging in chronic migraine

In chronic migraine, many neuroimaging studies with advanced techniques showed abnormalities in several brain areas involved in pain processing. The structural and functional dysfunctions are reported in cerebral areas localized in the brainstem and in the lateral and medial pain pathways. Using the advanced technique of volumetric MRI (voxel-based morphometry), reduction in the grey and white matter in brain areas of the pain network and increased density of the structures of the brainstem were observed in patients with episodic or chronic migraine. Most of the studies of functional anatomy in chronic migraine uses positron emission tomography (PET) and functional RM. These techniques could detect cerebral areas with regional cerebral blood flow and blood level oxygenation-dependent (BOLD) signal changes. Several PET and functional MRI experiments in patients with chronic migraine and drugs overuse before and after the withdrawal showed hypometabolism and hypoactivation in cortical areas involved in pain processing. These areas normalize their activity after detoxification, indicating reversible metabolic changes and BOLD signal changes as observed in other chronic pain. Functional and structural alterations observed in the cerebral areas of the pain network could be a result of a selective dysfunction of these regions due to cortical overstimulation associated with chronic pain. Advanced neuroimaging techniques have revolutionized the knowledge on chronic migraine, determining specific cortical substrate that could explain different forms of chronic migraine and perhaps the predisposition of patients to different therapeutic responses and to possible relapse in drug abuse.

The role of computed tomography in the diagnostic work-up of headache patients in Nigeria

OBJECTIVE

To determine the yield of computed tomography (CT) scan of the brain in the evaluation of patients presenting with headache at the University of Port Harcourt Teaching Hospital (UPTH).

BACKGROUND

Headache is a pain in the head or upper neck. It is one of the most common locations of pain in the body that leads patients to see a physician. CT scan is invaluable as an imaging tool in assessment of intracranial lesions that may present with headache.

METHODS

The records of all the patients referred from a variety of inpatient and outpatient settings to the radiology department of UPTH with the main complaint of headache for brain (CT) scan were identified. Data extracted include referral source, indication for CT, age, sex, presenting complaint, duration of headache, and CT findings. The data were analyzed using SPSS 14.0 statistical package.

RESULTS

A total of 80 patients with chronic or recurrent headache met the selection criteria. The age range was 16 to 85 years with a mean of 39.8 ± 14.62 years. There were 36 males and 44 females with male to female ratio of 1 :1.2. About half of the patients were ≤ 45 years. Of the total number, 72 (90%) patients had normal CT findings, 2 (2.5%) had cerebral atrophy, 2 (2.5%) had cerebral edema, 2 (2.5%) had intracerebral hematoma while 1 (1.25%) patient each had cerebral infarction and subdural hematoma, respectively. There was no case of brain tumor.

CONCLUSIONS

The yield of correctable abnormalities from routine CT scan of the brain in headache patients with normal neurologic findings is low and does not justify its use in a resource poor country. (Headache 2010;50:1346-1352).

The clinical neurophysiology of tension-type headache

Despite being widely investigated, the pathogenesis of tension-type headache (TTH) continues to be debated. Among the different approaches used to explore the mechanisms underlying TTH, clinical neurophysiology plays an important role. Studies to date have focused mainly on two areas: (1) evaluation of peripheral factors (i.e., by electromyography (EMG)); and (2) exploration of the role of the pain control system. In the second of these areas, a large number of studies have explored trigeminal pathways, in particular using reflexes (e.g., the trigeminofacial reflex, trigeminotrigeminal reflexes). More recently, the descending inhibitory system, known to modulate both the trigeminal and the spinal system, has also been investigated. In addition, several studies have sought to establish whether there are neurophysiological parameters that could be markers of this condition, but the results of these were inconclusive, since some abnormalities could frequently be observed in migraine too. This chapter critically reviews the clinical neurophysiology of TTH. It concludes that the majority of neurophysiological studies on TTH present serious methodological flaws that will have to be overcome to allow further understanding of the mechanisms of TTH.

Neuroimaging and clinical neurophysiology in cluster headache and trigeminal autonomic cephalalgias

Clinical neurophysiology and neuroimaging are two non-invasive approaches used to investigate the pathophysiological basis of primary headaches, including cluster headache (CH) and other trigeminal autonomic cephalalgias (TACs). Modern neuroimaging has revolutionized our understanding of the pathophysiology of primary headaches, and of TACs in particular, focusing on a cerebrovascular dysfunction hypothesis toward a central triggering cause. The introduction of single-photon emission computed tomography (SPECT), positron emission tomography (PET), and voxel-based morphometry has allowed us new insights into mechanisms underlying TACs and occurring during peripheral and/or central neuromodulation. The specific activation of neural structures that is observed exclusively in migraine and in TACs supports the hypothesis that primary headaches are driven predominantly by central nervous system dysfunction, and this has important implications from a therapeutic perspective. Neurophysiological examinations are of little value in the clinical setting; however, most of these tools offer vast potential for exploring further the pathophysiology of primary headaches and the effects of pharmacological treatments Trigeminofacial reflexes, the nociceptive flexion reflex, and evoked potentials have been used in TACs to explore the functional state of brainstem and spinal structures involved in pain processing, contributing to our understanding of the pathophysiology of these primary headaches.

Headache and cognitive profile in children: a cross-sectional controlled study

We investigated whether children affected by tension-type headache and migraine without aura, compared with a healthy control group that was matched by age, culturally and socioeconomically display a diverse intellectual functioning and have a separate “cognitive profile”. A cross-sectional study was conducted from January 2006 to November 2008 at “Sapienza University” in Rome. A total of 134 children were diagnosed as being affected by either migraine without aura (93) or tension-type headache (41). On the basis of our exclusion/inclusion criteria, we enrolled 82 of these 134 children, 63 of whom were affected by migraine without aura and 19 by tension-type headache. On entry, cognitive functions were assessed in both the affected subjects and the control group by the Wechsler Intelligence Scale for Children-revised. Significant differences were found between the headache and control groups in the mean total intelligence quotient and verbal intelligence quotient scores (p < 0.001). Significant negative correlations were found between the total intelligence quotient, verbal intelligence quotient, performance intelligence quotient and the frequency of attacks (r = −0.55 and p < 0.001, r = −0.61 and p < 0.001, r = −0.29 and p < 0.01, respectively), as well as between the total intelligence quotient score and the age at headache onset (r = 0.234, p < 0.05). Our results suggest that the cognitive profile of children affected by headache should be assessed at the first child neurology outpatient observation. From a therapeutic point of view, although within a normal range, the abilities most likely to be less brilliant in such children are verbal skills.

Implementation and evaluation of existing guidelines on the use of neurophysiological tests in non-acute migraine patients: a questionnaire survey of neurologists and primary care physicians

BACKGROUND AND PURPOSE

The main aims of this study were to evaluate: the diffusion, use and perception of the usefulness of the 2004 EFNS guidelines on neurophysiological testing in non-acute headache patients; the frequency with which the different neurophysiological tests were recommended in non-acute migraine patients by physicians aware or unaware of the guidelines; and the appropriateness of the reasons given for recommending neurophysiological tests.

METHODS

One hundred and fifty physicians selected amongst the members of the Italian societies of general practitioner (GPs), neurologists and headache specialists were contacted via e-mail and invited to fill in a questionnaire specially created for the study.

RESULTS

Ninety-two percent of the headache specialists, 8.6% of the neurologists and 0% of the GPs were already aware of the EFNS guidelines. A significantly higher proportion of headache specialists had not recommended any neurophysiological tests to the migraine patients they had seen in the previous 3 months, whereas these tests had frequently been prescribed by the GPs and neurologists. Overall, 80%, 42% and 42.6% of the reasons given by headache specialists, neurologists and GPs, respectively, for recommending neurophysiological testing in their migraine patients were appropriate (P < 0.01).

CONCLUSIONS

The diffusion of the EFNS guidelines on neurophysiological tests and neuroimaging procedures was found to be very limited amongst neurologists and GPs. The physicians aware of the EFNS guidelines recommended neurophysiological tests to migraine patients less frequently and more appropriately than physicians who were not aware of them. The most frequent misconceptions regarding neurophysiological tests concerned their perceived capacity to discriminate between migraine and secondary headaches or between migraine and other primary headaches.

Imaging patients with suspected brain tumour: guidance for primary care

The number of referrals by primary care practitioners to secondary care neurology services, particularly for headache, may be difficult to justify. Access to imaging by primary care practitioners could avoid referral without compromising patient outcomes, but the decision to refer is based on a number of complex factors. Due to the paucity of rigorous evidence in this area, available data are combined with expert opinion to offer support for GPs. The study suggests management for three levels of risk of tumour: red flags>1%; orange flags 0.1-1%; and yellow flags<0.1% but above the background population rate of 0.01%. Clinical presentations are stratified into these three groups. Important secondary causes of headache where imaging is normal should not be overlooked, and normal investigation does not eliminate the need for follow-up or appropriate management of headache.

Managing headache during pregnancy and lactation

Headache patterns for both primary and secondary headaches are often modified in women during pregnancy. Although approximately two thirds of women with migraines experience headache improvement during pregnancy; women who continue to suffer from migraine or other headaches during pregnancy need effective clinical care to include appropriate diagnostic studies, counseling about expectations during pregnancy and lactation, and modifications in therapeutic regimens to minimize risk to the fetus and nursing baby. This review describes the epidemiology of headache during pregnancy and lactation, to include both effects of these conditions on headache activity and possible concerns about how a maternal headache diagnosis may influence the course and outcome of pregnancy. Although restrictions in diagnostic testing and medication interventions are often necessary during pregnancy and breastfeeding, this review describes evaluation and management strategies that provide effective clinical care while minimizing risk to the developing baby.

Evaluation and proposal for optimalization of neurophysiological tests in migraine: part 1--electrophysiological tests

Neurophysiological testing has become a valuable tool for investigating brain excitability and nociceptive systems in headache disorders. Previous reviews have suggested that most neurophysiological tests have limited value for headache diagnosis, but a vast potential for exploring the pathophysiology of headaches, the central effects of certain pharmacological treatments and phenotype-genotype correlations. Many protocols, however, lack standardization. This meta-analytical review of neurophysiological methods in migraine was initiated by a task force within the EUROHEAD project (EU Strep LSHM-CT-2004-5044837-Workpackage 9). Most of the neurophysiological approaches that have been used in headache patients are reviewed, i.e. evoked potentials, nociception-specific blink reflex, single-fibre electromyography, neuroimaging methods (functional MRI, PET, and voxel-based morphometry) and the nitroglycerin attack-provoking test. For each of them, we summarize the results, analyse the methodological limitations and propose recommendations for improved methodology and standardization of research protocols. The first part is devoted to electrophysiological methods, the second to neuroimaging techniques and the NTG test.

Kopfschmerzpatienten im klinischen Alltag

In routine clinical practice, the question whether instrumental examinations of patients with headaches should be carried out, is not always easy. If secondary headaches are suspected, with atypical presentation and focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. In primary headaches, such as migraine, tension headache or trigemino-autonomic headaches, no further diagnostic procedures are warranted, as long as the clinical presentation is typical (i.e. corresponds to the International Headache Society guidelines) and neurological examination is normal. This article reviews the evidence from the literature and recommendations of European and American task forces regarding the use of instrumental examinations in case of non-acute primary headache.

Trigeminal-autonomic headaches in daily clinical practice

Following the revised International Headache Society criteria, a group of short-lasting headaches associated with autonomic symptoms, the so called trigeminal autonomic cephalgias, were newly recognized. The trigeminal autonomic cephalgias include cluster headache, paroxysmal hemicranias and a syndrome involving short-lasting unilateral neuralform cephalgias with conjunctival injection and tearing (SUNCT) syndrome. In all of these syndromes, the half-sided head pain and cranial autonomic symptoms are prominent. All of the trigeminal autonomic cephalgias differ in duration, frequency and rhythmicity of the attacks, the intensity of pain and autonomic symptoms, as well as treatment options. This review gives a brief clinical description of the headache disorders and recent pathophysiological findings, as well as an overview of the treatment of cluster headache, paroxysmal hemicranias and SUNCT syndrome.

EFNS guidelines on the treatment of cluster headache and other trigeminal-autonomic cephalalgias

Cluster headache and the other trigeminal-autonomic cephalalgias [paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome] are rare but very disabling conditions with a major impact on the patient's quality of life. The objective of this study was to give evidence-based recommendations for the treatment of these headache disorders based on a literature search and consensus amongst a panel of experts. All available medical reference systems were screened for any kind of studies on cluster headache, paroxysmal hemicrania and SUNCT syndrome. The findings in these studies were evaluated according to the recommendations of the European Federation of Neurological Societies resulting in level A, B or C recommendations and good practice points. For the acute treatment of cluster headache attacks, oxygen (100%) with a flow of at least 7 l/min over 15 min and 6 mg subcutaneous sumatriptan are drugs of first choice. Prophylaxis of cluster headache should be performed with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy or tolerability). Although no class I or II trials are available, steroids are clearly effective in cluster headache. Therefore, the use of at least 100 mg methylprednisone (or equivalent corticosteroid) given orally or at up to 500 mg i.v. per day over 5 days (then tapering down) is recommended. Methysergide, lithium and topiramate are recommended as alternative treatments. Surgical procedures, although in part promising, require further scientific evaluation. For paroxysmal hemicranias, indomethacin at a daily dose of up to 225 mg is the drug of choice. For treatment of SUNCT syndrome, large series suggest that lamotrigine is the most effective preventive agent, with topiramate and gabapentin also being useful. Intravenous lidocaine may also be helpful as an acute therapy when patients are extremely distressed and disabled by frequent attacks.

A review of diagnostic and functional imaging in headache

The neuroimaging of headache patients has revolutionised our understanding of the pathophysiology of primary headaches and provided unique insights into these syndromes. Modern imaging studies point, together with the clinical picture, towards a central triggering cause. The early functional imaging work using positron emission tomography shed light on the genesis of some syndromes, and has recently been refined, implying that the observed activation in migraine (brainstem) and in several trigeminal-autonomic headaches (hypothalamic grey) is involved in the pain process in either a permissive or triggering manner rather than simply as a response to first-division nociception per se. Using the advanced method of voxel-based morphometry, it has been suggested that there is a correlation between the brain area activated specifically in acute cluster headache--the posterior hypothalamic grey matter--and an increase in grey matter in the same region. No structural changes have been found for migraine and medication overuse headache, whereas patients with chronic tension-type headache demonstrated a significant grey matter decrease in regions known to be involved in pain processing. Modern neuroimaging thus clearly suggests that most primary headache syndromes are predominantly driven from the brain, activating the trigeminovascular reflex and needing therapeutics that act on both sides: centrally and peripherally.

Trigeminal sensory pathway function in patients with SUNCT

OBJECTIVE

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is a rare primary headache whose origins are unclear. To seek information on its pathophysiology, we studied the trigeminal Abeta and Adelta pathways by recording trigeminal reflexes and laser evoked potentials (LEPs) in patients with SUNCT.

METHODS

Trigeminal reflexes and LEPs were recorded in 11 consecutive patients. Ten patients had neuroimaging evidence documenting idiopathic SUNCT and one had a posterior fossa tumour that compressed the trigeminal nerve thus causing symptomatic SUNCT.

RESULTS

Whereas the patients with idiopathic SUNCT had normal trigeminal reflex and LEP responses, the patient with symptomatic SUNCT had abnormal responses.

CONCLUSIONS

Our neurophysiological findings show that idiopathic SUNCT spares the trigeminal sensory pathways whereas symptomatic SUNCT does not.

SIGNIFICANCE

Neurophysiological testing can easily differentiate the idiopathic and symptomatic forms of SUNCT. It also suggests that the two forms are pathophysiologically distinct entities.

Local Decrease of Pressure Pain Threshold in Nummular Headache

BACKGROUND

Nummular headache (NH) is a primary disorder presenting with localized pain that is circumscribed to a coin-shaped area of the head surface.

METHODS

In 12 patients with NH (3 men and 9 women, 21 to 67 years old), we measured the pressure pain threshold (PPT) in several points while they were headache-free. The following cephalic and extracephalic points were explored: the symptomatic cranial area, a symmetrical point on the nonsymptomatic side, and 3 standardized pairs of symmetrical points (anterior part of the temporal muscle, upper trapezius muscle, and distal dorsal part of the second finger). Three consecutive PPT readings were obtained with an algometer on each point, and the repeatability of these measurements was always high (ICC: 0.93 to 0.97).

RESULTS

Mean PPT was lower in the symptomatic cranial area than in the contra-lateral symmetrical point (1.8 +/- 0.6 kg/cm(2) vs 2.4 +/- 0.6 kg/cm(2); P < .001), whereas in the remaining reference points PPT was almost equal on both sides.

CONCLUSIONS

According to these data, NH seems to be associated with a local increase of pain sensitivity to mechanical stimulation.