Predictors of successful primary care detoxification treatment for medication-overuse headache

OBJECTIVES

To investigate predictors for successful treatment outcome after a brief intervention (BI) for medication-overuse headache (MOH).

MATERIALS AND METHODS

This study evaluated predictors of successful withdrawal among patients initially participating in a pragmatic cluster-randomized controlled trial with single crossover in Norwegian general practice (the BIMOH study). BI (early or after crossover) was compared to business as usual (BAU) for the treatment of MOH. Patients were followed up 3 months after the BI.

RESULTS

In total, 46 patients had the chance to receive the BI (24 early and 22 after crossover) and were included in the predictor analyses. The mean reduction in headache and medication days/month from baseline for the BI was 6.9 (95% CI: 4.8-9.1) and 10.9 (8.1-13.6). The mean percentage reduction in headache and medication days was 30.5% (21.4-39.7) and 50.4% (39.5-61.3). Only five patients started prophylactic medication. Neither age, gender, co-occurrence of migraine, main type of overused drug at baseline nor Severity of Dependence Scale score at baseline predicted successful withdrawal in the prespecified analyses. Headache days/month and medication use at baseline were significant predictors in exploratory analyses with more headache and medication days predicting worse outcome.

CONCLUSIONS

Brief intervention for MOH is a simple and effective intervention in primary care. As the only identified predictors were frequency of headache and medication use, we conclude that treatment for all MOH patients should be attempted in primary care before referral. A raised awareness of MOH is important, as the condition is highly preventable and treatable.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01314768.

Genetics of Migraine without Aura, Migraine with Aura, Migrainous Disorder, Head Trauma Migraine without Aura and Tension-Type Headache

This review is a tribute to Professor Jes Olesen involvement in the genetics of migraine and tension-type headache as it is coming up to his 60th birthday.

Sporadic Hemiplegic Migraine is an Aetiologically Heterogeneous Disorder

In order to better understand sporadic hemiplegic migraine (SHM) and particularly its relation to familial hemiplegic migraine (FHM), migraine without aura (MO) and typical migraine with aura (typical MA), we investigated the occurrence of MO and typical MA among probands with SHM and their first-degree relatives. The pattern of familial aggregation of MO and typical MA was assessed by population relative risk calculations. A total of 105 SHM probands and 483 first-degree relatives were identified in the Danish population. Compared with the general population, SHM probands had no increased risk of MO, but a highly increased risk of typical MA. First-degree relatives of all SHM probands had an increased risk of both MO and typical MA, whereas first-degree relatives of probands with exclusively SHM had no increased risk of MO but an increased risk of typical MA. Our data suggest that SHM is a genetically heterogeneous disorder.

Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial

Background and purpose

To investigate the efficacy of chiropractic spinal manipulative therapy (CSMT) for migraineurs.

Methods

This was a prospective three‐armed, single‐blinded, placebo, randomized controlled trial (RCT) of 17 months duration including 104 migraineurs with at least one migraine attack per month. The RCT was conducted at Akershus University Hospital, Oslo, Norway. Active treatment consisted of CSMT, whereas placebo was a sham push manoeuvre of the lateral edge of the scapula and/or the gluteal region. The control group continued their usual pharmacological management. The RCT consisted of a 1‐month run‐in, 3 months intervention and outcome measures at the end of the intervention and at 3, 6 and 12 months follow‐up. The primary end‐point was the number of migraine days per month, whereas secondary end‐points were migraine duration, migraine intensity and headache index, and medicine consumption.

Results

Migraine days were significantly reduced within all three groups from baseline to post‐treatment (P < 0.001). The effect continued in the CSMT and placebo group at all follow‐up time points, whereas the control group returned to baseline. The reduction in migraine days was not significantly different between the groups (P > 0.025 for interaction). Migraine duration and headache index were reduced significantly more in the CSMT than the control group towards the end of follow‐up (P = 0.02 and P = 0.04 for interaction, respectively). Adverse events were few, mild and transient. Blinding was strongly sustained throughout the RCT.

Conclusions

It is possible to conduct a manual‐therapy RCT with concealed placebo. The effect of CSMT observed in our study is probably due to a placebo response.

Variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A are associated with intermediate Charcot-Marie-Tooth disease in a Norwegian family

Introduction

Charcot–Marie–Tooth disease (CMT) is a heterogeneous inherited neuropathy. The number of known CMT genes is rapidly increasing mainly due to next‐generation sequencing technology, at present more than 70 CMT‐associated genes are known. We investigated whether variants in the DCTN2 could cause CMT.

Material and methods

Fifty‐nine Norwegian CMT families from the general population with unknown genotype were tested by targeted next‐generation sequencing (NGS) for variants in DCTN2 along with 32 CMT genes and 19 other genes causing other inherited neuropathies or neuronopathies, due to phenotypic overlap. In the family with the DCTN2 variant, exome sequencing was then carried out on all available eight family members to rule out the presence of more potential variants.

Results

Targeted NGS identified in one family a variant of DCTN2, c.337C>T, segregating with the phenotype in five affected members, while it was not present in the three unaffected members. The DCTN2 variant c.337C>T; p.(His113Tyr) was neither found in in‐house controls nor in SNP databases. Exome sequencing revealed a singular heterozygous shared haplotype containing four genes, DCTN2,DNAH10,LRIG3, and MYO1A, with novel sequence variants. The haplotype was shared by all the affected members, while the unaffected members did not have it.

Conclusions

This is the first time a haplotype on chromosome 12 containing sequence variants in the genes DCTN2,DNAH10,LRIG3, and MYO1A has been linked to an inherited neuropathy in humans.

Familial Cluster Headache. Is Atypical Cluster Headache in Family Members Part of the Clinical Spectrum?

Familial cluster headache (CH) was analysed in 21 Swedish families. Diagnosis was made according to The International Classification of Headache Disorders 2004. We identified 55 affected, of whom 42 had episodic or chronic CH, one had probable CH and 12 had atypical symptoms. The atypical cases did not fulfil the diagnostic criteria for CH, but had clinical symptoms with more resemblance to CH than to migraine or other trigeminal autonomic cephalgia syndromes. The overall male : female ratio was 1.8 : 1. The overall mean age at onset was significantly lower in the second/third generation than in the first generation (mean age at onset 22 vs. 31 years, SD ± 7 vs. 13 years; P < 0.01). This may be anticipation or selection bias, since individuals with late age at onset from the second/third generation may not yet have symptoms. The prevalence of migraine was 24% (13/55), i.e. similar to the prevalence in the general population. The high incidence of atypical CH cases in the Swedish families with other members affected with CH may suggest that the spectrum of CH is broader than previously thought. We suggest that atypical CH in CH families may represent an expanded spectrum of the disease with a common aetiology, i.e. a common genetic background.

Prognosis of Migraine with Aura

The present study is a 16-year follow-up study assessing the long-term outcome of migraine with aura (MA). Additionally possible predictive factors in the prognosis of MA were evaluated. Patients were recruited from the files of Danish headache clinics. A total of 53 patients (11M:42F) with MA (IHS criteria) participated in a follow-up interview. At follow-up attacks had ceased (no MA for 2 years) in 36% of patients. Attacks had ceased in 55% of males and 31% of females ( P = 0.17). Attacks had ceased in 41% of patients with visual aura without other aura symptoms and in 25% of those with sensory or aphasic aura besides their visual aura ( P = 0.36). Among those with attacks of MA at follow-up frequency of attacks and headache intensity was improved in 44% and 41% of the patients, respectively. The results point to a favourable evolution of MA and suggest possible predictive factors.

Disability, anxiety and depression in patients with medication-overuse headache in primary care - the BIMOH study

BACKGROUND AND PURPOSE

Medication-overuse headache (MOH) is common in the general population. Detoxification is the general treatment principle for MOH. The present paper is based on a study of a brief intervention (BI) for MOH in primary care. New data on headache disability and the Hospital Anxiety and Depression Scale (HADS) for MOH patients compared to population controls with and without chronic headache are presented and compared to previously published main outcome data.

METHODS

This was a double-blind pragmatic cluster randomized controlled trial carried out amongst 50 general practitioners in Norway. The BI was compared to business as usual (BAU) and population controls, and patients were followed up after 3 months. Primary outcomes were headache and medication days per month after 3 months. Headache disability and HADS were also measured as secondary outcomes.

RESULTS

Sixty MOH patients and 40 population controls were included. BI was significantly better than BAU after 3 months regarding primary outcomes. Non-intervention population controls did not change. The MOH patients had significantly higher headache disability and anxiety scores than the population controls.

CONCLUSIONS

Patients with MOH are a highly disabled group where anxiety and depression are important comorbidities. Detoxification of MOH by a BI in primary care is effective and has potential for saving resources for more treatment-resistant cases in neurologist care.

Monitoring Network Confirms Land Use Change is a Substantial Component of the Forest Carbon Sink in the eastern United States

Quantifying forest carbon (C) stocks and stock change within a matrix of land use (LU) and LU change is a central component of large-scale forest C monitoring and reporting practices prescribed by the Intergovernmental Panel on Climate Change (IPCC). Using a region-wide, repeated forest inventory, forest C stocks and stock change by pool were examined by LU categories. In eastern US forests, LU change is a substantial component of C sink strength (~37% of forest sink strength) only secondary to that of C accumulation in forests remaining forest where their comingling with other LUs does not substantially reduce sink strength. The strongest sinks of forest C were study areas not completely dominated by forests, even when there was some loss of forest to agriculture/settlement/other LUs. Long-term LU planning exercises and policy development that seeks to maintain and/or enhance regional C sinks should explicitly recognize the importance of maximizing non-forest to forest LU changes and not overlook management and conservation of forests located in landscapes not currently dominated by forests.

Aortic root pathology in Marfan syndrome increases the risk of migraine with aura

Aim: To assess the lifetime prevalence of migraine in patients with Marfan syndrome (MFS) and to investigate a history of aortic root replacement (AR) as a possible risk factor.

Methods: In a multicentre study 123 MFS patients ( n = 52 with AR, n = 71 without AR), 82 age- and sex-matched controls and 51 patients with AR but without MFS, were interviewed using a semi-structured headache questionnaire. A multinomial logistic regression model was used to investigate risk factors for migraine with and without aura, adjusting for age and gender.

Results: Lifetime migraine prevalence was increased in female MFS patients (51%) compared to healthy female controls (29%), p = 0.017. In males lifetime migraine prevalence among MFS patients was only numerically increased. Lifetime prevalence of migraine with aura was increased among MFS patients compared to healthy controls both in males (19% vs. 3%, p = 0.048) and females (30% vs. 14%, p = 0.049). A history of AR, independently from MFS, gender and age, increased the lifetime prevalence of migraine with aura (OR 3.1 [1.2–8.0]). In all but one patient migraine started before the AR.

Conclusions: The lifetime prevalence of migraine with aura, but not migraine without aura, is increased in patients with MFS. This association is driven by a history of AR. The replacement procedure itself is unlikely to be causally associated with migraine as in nearly all subjects, migraine started before the procedure. However this study adds to the evidence that underlying vessel wall pathology may be involved in migraine with aura.

Personality traits and psychological distress in persons with chronic tension-type headache. The Akershus study of chronic headache

OBJECTIVES

To explore the relationship between chronic tension-type headache (CTTH) and psychological factors (personality traits and psychological distress) in a population-based sample and to determine the influence of headache frequency and medication days.

METHODS

An age- and sex-stratified random sample of 30,000 persons aged 30-44 years from the general population received a mailed questionnaire. Those with a self-reported chronic headache were interviewed by neurological residents. The questionnaire response rate was 71%, and the rate of participation in the interview was 74%. The International Classification of Headache Disorders was used. Personality traits were assessed by the Eysenck Personality Questionnaire (EPQ), neuroticism and lie scale, and level of psychological distress, by the Hopkins Symptom Checklist-25 (HSCL-25). For comparison, cross-sectional data from the Danish and the Norwegian general population using the same instruments were used.

RESULTS

Persons with CTTH had a significantly higher neuroticism score and a significantly higher level of psychological distress than the general population. Headache- or medication days per month had no significant influence on the neuroticism- and lie scores or the HSCL-25 score.

CONCLUSIONS

Persons with CTTH have a high level of neuroticism and psychological distress. This can be either a primary or a secondary effect related to the premorbid psyche or caused by the chronic pain and is a question that future studies should address.

Reduction in medication-overuse headache after short information. The Akershus study of chronic headache

OBJECTIVE

our aim was to investigate the course of medication-overuse headache in the general population and the effect of simple advice regarding medication overuse.

DESIGN

prospective cohort study. Participants were identified in a cross-sectional epidemiological sample of 30000 persons aged 30-44 from the general Norwegian population. People with chronic headache (≥ 15 days per month for at least 3 months) and medication overuse received short information about the possible role of medication overuse in headache chronification. A cohort was followed up 1½ years later. The diagnostic criteria of the International Classification of Headache Disorders and data splitting methodology were used.

SETTING

Akershus University Hospital, Oslo, Norway.

PARTICIPANTS

a total of 109 participants with chronic primary headache and medication overuse were available for follow-up (85% participation rate).

MAIN OUTCOME MEASURE

  Change in medication days and headache days per month.

RESULTS

at baseline chronic tension-type headache was found in 92% of participants; 8% had chronic migraine or new daily persistent headache. Migraine co-occurrence was found in 53%. The mean duration of chronic headaches were 8-18 years, the mean duration of medication overuse between 5 and 10 years prior to intervention. At follow up, the mean medication days were significantly reduced from 22 days to 6 days per month, and 76% no longer had medication overuse. Forty-two percent no longer had chronic headache and the headache index was reduced by 24%.

CONCLUSION

our examination and short information served as a modified brief intervention which can improve chronic headache and medication overuse in the general population.

Genetics of dementia

Dementia is a syndrome and not a single disease. Approximately 0.5% of those with Alzheimer's disease have an autosomal dominant inherited early onset Alzheimer's disease, caused by mutations in the APP, PSEN1 or PSEN2 gene. A large population-based twin study of late onset Alzheimer's disease supports complex inheritance. The APOE epsilon4 allele is a major risk factor for late onset Alzheimer's disease, whereas the epsilon2 allele has a protective effect. Two large size genome-wide association studies from two Internationals study groups recently identified the genes CLU, PICALM and CRI to be important for late onset Alzheimer's disease. Stroke is like dementia a syndrome and not a single disease. CADASIL is the most common autosomal dominant inherited cause of stroke and vascular dementia. CADASIL is caused by mutations in the NOTCH3 gene, which encodes a single-pass transmembrane receptor. Stroke can cause dementia, as it is the stroke itself rather than the underlying vascular risk factors that cause the dementia.

Genetic epidemiology of Charcot-Marie-Tooth in the general population

BACKGROUND AND PURPOSE

the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking.

METHODS

our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically.

RESULTS

two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes.

CONCLUSIONS

CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.

Secondary chronic cluster headache due to trigeminal nerve root compression

A 50-year-old woman had a gradual onset of chronic headache located in the right temporal region and a burning sensation in the root of the tongue which over a year evolved into chronic cluster headache with a milder chronic headache in-between the severe cluster headache attacks. A cerebral magnetic resonance imaging (MRI) showed vascular compression of the trigeminal nerve root on the pain side. Neurosurgery microvascular decompression relieved the patient's chronic cluster headache, the chronic intermittent headache and the burning tongue sensation. The effect was persistent at a 1 year follow-up. Patients with atypical symptoms of cluster headache should be examined with cerebral MRI angiography of arteries and veins to exclude symptomatic causes.

An adapted Severity of Dependence Scale is valid for the detection of medication overuse: the Akershus study of chronic headache

BACKGROUND AND OBJECTIVE

Medication overuse headache is a common subtype of chronic headache involving the overuse of simple analgesics, opioids, ergotamine or triptans or combinations of these medications. Medication overuse may worsen the headache and has been described to have many characteristics similar to addiction. The purpose of this study was to validate and optimize the Severity of Dependence Scale (SDS) for use amongst people with chronic headache.

DESIGN/SETTING

In a cross-sectional epidemiological survey, an age- and gender-stratified sample of 30,000 30- to 44-year-old people were recruited via a posted questionnaire. Those with self-reported chronic headache were interviewed by neurological residents at Akershus University Hospital, Oslo. Headache was classified according to the International Classification of Headache Disorders. Split file methodology was employed for data analysis.

MAIN OUTCOME MEASURE

Severity of Dependence Scale score in those with and without medication overuse.

RESULTS

  Severity of Dependence Scale score was a significant predictor of medication overuse amongst chronic headache patients. Medication overuse could be predicted with sensitivity, specificity, positive and negative predictive values of 0.79, 0.84, 0.84 and 0.79, respectively, in men and 0.76, 0.77, 0.73 and 0.79 in women. Linear regression and factor analysis suggested a redundancy for the SDS question 'Do you think your use of your headache medication was out of control?' Removal of this question improved Chronbach's alpha=0.76.

CONCLUSION

The SDS is valid for detecting medication overuse and dependency like behaviour amongst people with chronic headache. The adapted version may be used to identify chronic headache patients who may benefit from detoxification.

Prevalence of New Daily Persistent Headache in the General Population. The Akershus Study of Chronic Headache

The aim of the present study was to investigate the prevalence of new daily persistent headache (NDPH) in the general population, and compare the clinical characteristics of NDPH and chronic tension-type headache (CTTH). This is a population-based cross-sectional study. A random sample of 30 000 persons aged 30-44 years was drawn from the population of Akershus County, Norway. A postal questionnaire was screened for chronic headache. Those ( n = 633) with self-reported chronic headache within the last month and/or year were invited to an interview and examination by a neurological resident. A follow-up interview was conducted after 1.5-3 years. The headaches were diagnosed according to the International Classification of Headache Disorders, 2nd edn and relevant revisions. The response rate of the questionnaire was 71% and the participation rate of the interview was 74%. Four persons, three men and one woman, had NDPH. The overall 1-year prevalence of NDPH was 0.03%. The clinical characteristics of NDPH and CTTH were similar, except for the sudden onset in NDPH. Three of the four persons with NDPH had medication overuse. Follow-up disclosed that the symptomatology of NDPH is not unchangeable, since two persons had improvement of their NDPH. NDPH is rare and occurs in one of 3500 persons from the general population of 30-44-year-olds. It is often associated with medication overuse.

What is chronic headache in the general population? The Akershus study of chronic headache

BACKGROUND

Studies of chronic headache including both primary and secondary causes from the general population is lacking.

AIMS

To provide prevalence data on chronic headache.

MATERIALS & METHODS

We studied chronic headaches defined as headache 15 days per month on average for at least 3 months in the general population. An age and gender stratified random sample of 30,000 persons aged 30-44 years received a mailed questionnaire. Those with self-reported headache on 15 days or more within the last month and/or headache on more than 180 days within the last year were invited to an interview and examination by a neurological resident. The criteria of the International Classification of Headache Disorders were applied.

RESULTS

Chronic headache occurred in 3.71% of the general population.Women had chronic headache twice as often as men. About half of those with chronic headache also had medication overuse, irrespectively of the types of chronic headache. Secondary chronic headaches attributed to chronic rhinosinusitis, head injury, whiplash injury and cervicogenic headache were relatively frequent, i.e. from 1 of 300 to 1 of 600 persons from the general population.

DISCUSSION

Primary and secondary chronics headaches should not be ignored.

CONCLUSION

Primary and secondary chronic headaches are common in the general population.

The Severity of Dependence Scale detects people with medication overuse: the Akershus study of chronic headache

OBJECTIVE

To evaluate the Severity of Dependence Scale (SDS) in people with primary chronic headache and analyse the pattern of medication overuse.

DESIGN

Cross sectional epidemiological survey. A posted questionnaire screened for chronic headache. Neurological residents interviewed those with self-reported chronic headache. The International Classification of Headache Disorders was used. Split file methodology was employed for data analysis.

SETTING

Akershus University Hospital, Oslo, Norway.

PARTICIPANTS

A random sample of 30,000 people, aged 30-44 years, from the general population of Akershus County, Norway. 405 people had primary chronic headache.

MAIN OUTCOME MEASURE

SDS score in those with and without medication overuse.

RESULTS

The screening questionnaire response rate was 71% and the participation rate of the interview 74%. Among 405 people with primary chronic headache, 95% had chronic tension-type headache, 4% had chronic migraine and <1% had other primary chronic headaches. Of 386 persons with chronic tension-type headache, 44% had medication overuse and 47% had co-occurrence of migraine. Simple analgesics, combination analgesics, triptans, ergotamine, opioids and a combination of acute medications were overused by 65%, 27%, 4%, <1%, 1% and 2% of people, respectively. The mean SDS score was significantly higher in those with than in those without medication overuse (5.6 vs 2.7; p<0.001).

CONCLUSION

The SDS questionnaire detects medication overuse and dependency-like behaviour in persons with primary chronic headache.

Chronic rhinosinusitis gives a ninefold increased risk of chronic headache. The Akershus study of chronic headache

We studied the association of chronic headache and chronic rhinosinusitis in 30 000 persons aged 30–44 years from the general population. They received a mailed questionnaire. Those with possible chronic headache were interviewed by neurological residents. The criteria of the American Academy of Otolaryngology—Head and Neck Surgery were applied to diagnose headache attributed to chronic rhinosinusitis (HACRS), otherwise the International Classification of Headache Disorders was used. The questionnaire response rate was 71%, and the participation rate of the interview was 74%. Compared with the general population, persons with chronic rhinosinusitis have an at least ninefold increased risk of having chronic headache. A 3-year follow-up showed that HACRS symptoms were significantly improved after treatment with nasal surgery, nasal corticosteroids, discontinuation of overused headache medications and discontinuation of nasal decongestants or unspecified reasons. Chronic rhinosinusitis is significantly associated with chronic headache, and HACRS is likely to be a distinct type of headache.

A vertical VAS is a valid instrument for monitoring headache pain intensity

Visual analogue scales (VAS) are well-validated instruments for assessing pain intensity, but have an impractical format. The aim of the study was to validate a vertical against a horizontal VAS for pain intensity registration. Out-patients with headache or non-headache pain were included. Participants completed a horizontal and a vertical VAS. Both were completed twice for test-retest. Headache was diagnosed according to the International Classification of Headache Disorders, 2nd edition. The results on vertical and horizontal VAS did not differ significantly in the different headache or chronic pain groups. For test-retest evaluation, effect sizes and Cohen's delta values were < 0.029 with < 1.5% change from test to retest (P < 0.01). Correlation coefficients were > 0.95. Bland-Altman analysis showed good agreement between vertical and horizontal scores with correlation coefficients > 0.84. A vertical VAS is equally valid as a horizontal VAS for registration of pain intensity in headache and non-headache patients.

Interrelation of Chronic Tension-Type Headache With and Without Medication Overuse and Migraine in the General Population: The Akershus Study of Chronic Headache

We studied the interrelation of chronic tension-type headache with and without medication overuse (CTTH) and migraine in a random sample of 30 000 persons aged 30–44 years. They received a mailed questionnaire. Those with a possible chronic headache were interviewed by neurological residents. The International Classification of Headache Disorders was used. A total of 386 persons had CTTH. Compared with the general population, men had a 2.8-fold and women a 2.4-fold significantly increased risk of migraine without aura (MO). The risk of migraine with aura (MA) was not increased. The mean age at onset of CTTH was significantly higher in those with than in those without co-occurrence of MO. Bilateral MO attacks were significantly more frequent in those with age at onset of CTTH prior to age at onset of MO compared with those with age at onset in reverse order. CTTH and MO are interrelated, possibly in a complex matter. In contrast, CTTH and MA are not interrelated.

Prevalence of secondary chronic headaches in a population-based sample of 30-44-year-old persons. The Akershus study of chronic headache

We studied secondary chronic headaches (> or = 15 days/month for at least 3 months) in a random sample of 30 000 persons aged 30-44 years. They received a mailed questionnaire. Those with self-reported chronic headache within the last month and/or year were invited to an interview and examination by a neurological resident. The criteria of the International Classification of Headache Disorders (ICHD-II) were applied. The questionnaire response rate was 71%, and the participation rate of the interview was 74%. Of the 633 participants, 298 had a secondary chronic headache. The 1-year prevalence of secondary chronic headache was 2.14%, i.e. chronic posttraumatic headache 0.21%, chronic headache attributed to whiplash injury 0.17%, post-craniotomy headache 0.02%, medication-overuse headache (MOH) 1.72%, cervicogenic headache 0.17%, headache attributed to chronic rhinosinusitis 0.33% and miscellaneous headaches 0.04%. The majority of those with ICHD-II-defined secondary chronic headache had MOH, while about one-third had other secondary headaches often in combination with MOH.

Which strategy should be applied? Design of a Norwegian epidemiological survey on chronic headache

BACKGROUND

Large-scale population-based epidemiological surveys on chronic headache based on clinical interview by a physician are lacking.

AIMS OF THE STUDY

To describe a method that aims to provide valid information on chronic headache.

METHOD

A self-administered questionnaire including two questions about headache frequency within the last month and within the last year was used to screen for possible chronic headache. Respondents with self-reported headache more than half of the days were interviewed by neurological residents with experience in headache diagnostics.

DISCUSSION

Previous studies have shown that a single question from a self-administered questionnaire can be used to screen for chronic headache. However, a precise headache diagnosis requires an interview by a physician experienced in headache diagnostics, as diagnoses extracted from questionnaires or provided by lay interviewers are not sufficiently precise.

CONCLUSIONS

A combination of a screening questionnaire and a clinical interview by a physician is likely to be a cost-effective method to conduct an epidemiological survey on chronic headache.

Symptomatic Charcot-Marie-Tooth? A pair of concordant monozygotic twins

BACKGROUND

A pair of monozygotic twin brothers were referred due to hereditary peripheral neuropathy resembling late onset Charcot-Marie-Tooth (CMT).

AIM OF THE STUDY

Diagnostic classification of the twin pair.

METHOD

Clinical, neurological, genetical and neurophysiological examination, and molecular genetic testing.

RESULTS

The clinic and neurophysiology was compatible with CMT disease with late onset. Molecular genetic analysis excluded mutations in PMP22, connexin32, MPZ, LITAF and MFNZ genes, as well as duplication and deletion of PMP22.

CONCLUSIONS

The twins were employed in PVC production and developed symptoms after 14 years of massive exposure. We think that the heavy exposure to various neurotoxic compounds caused symptoms that mimic late-onset CMT. However, the twins had distal dysesthesia which is unusual in inherited neuropathies. This illustrates the importance of an occupational history even in the molecular genetic era.

Increased risk of migraine in Marfan's syndrome?

OBJECTIVE

To study the prevalence of migraine in Marfan's syndrome.

MATERIAL AND METHODS

Patients were recruited from Landsforeningen (a patient organization) for Marfan's syndrome. A total of 46 persons were eligible for a validated semi-structured telephone interview by a physician trained in headache diagnostics.

RESULTS

The prevalence of migraine without aura was 13% among men and 40% among women. The prevalence of migraine with aura was 44% among men and 37% among women. The overall prevalence of migraine was 63% with an equal sex ratio. This corresponds to a 3.6- and 2.0-fold significant increased risk among men and women, respectively, compared with the general population.

CONCLUSION

The high prevalence and equal sex ratio of migraine is puzzling and likely to be secondary to Marfan's syndrome. It might be associated with dural ectasia, as the prevalence of dural ectasia is similar to that of migraine in Marfan's syndrome.

A genome-wide scan and HCRTR2 candidate gene analysis in a European cluster headache cohort

OBJECTIVE

To investigate the molecular genetic basis of cluster headache (CH), using a genome-wide scan and candidate gene strategy.

METHODS

Northern European CH families and a case-control cohort of Danish, Swedish, and British origin (total n = 259 sporadic CH patients), including 267 control subjects matched for ancestry, participated in the study. A genome-wide genetic screen using approximately 400 microsatellite markers was performed for five informative Danish CH families. Additional markers were typed for those loci generating statistical evidence suggestive of linkage, together with genotypes for 111 individuals from further Danish and Italian kindreds. Sporadic CH patients and controls were investigated by association analysis for variation in the candidate gene, HCRTR2. Finally, complete HCRTR2 sequencing was undertaken for eight independent probands.

RESULTS

Potential linkage was identified at four possible disease loci in Danish kindreds, yet no single chromosome location generated a lod or NPL score of recognized significance. No deleterious sequence variants of the HCRTR2 gene were detected by comparison to wild-type sequence. Association of the HCRTR2 gene was not replicated in this large dataset, even when the data were stratified into distinct populations.

CONCLUSIONS

Cluster headache is a complex genetic disorder, with possible phenotypic and genetic heterogeneity compounding attempts at gene identification.

Increased risk of migraine with typical aura in probands with familial hemiplegic migraine and their relatives

We investigated the occurrence of migraine without aura (MO) and migraine with typical aura (MA) amongst probands with familial hemiplegic migraine (FHM) and their first degree relatives in order to evaluate the relations between these syndromes. A total of 44 FHM probands and 240 first degree relatives were identified in the Danish population. The pattern of familial aggregation was assessed by population relative risk (PRR) calculations. Amongst FHM probands the PRR of MO was 1.5 (95% CI: 0.8-2.2), whereas the PRR of MA was 7.1 (95% CI: 5.0-9.2). Thus, compared with the general population, FHM probands had no increased risk of MO but a significantly increased risk of MA. A similar pattern was seen amongst their first degree relatives, who had no increased risk of MO, whereas the risk of MA was significantly increased; 7.6 times in FHM-affected first degree relatives and 2.4-times in non-FHM-affected first degree relatives. These results are contrary to a sharing of genetic mechanisms between FHM and MO. Furthermore, they suggest that the genetic abnormality causing FHM may also cause attacks with the symptomatology of MA.

A population-based study of familial hemiplegic migraine suggests revised diagnostic criteria

Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine with aura. The clinical characteristics of FHM have been described previously in selected materials or case studies, but population-based studies are important in order to analyse the full spectrum of the disorder. The aim of the present study was to perform a systematic search for familial cases of migraine with an aura that included motor weakness in order to generate non-selected material of as many FHM cases as possible in the Danish population of 5.2 million inhabitants, and to compare this material with already available population-based clinical descriptions of migraine with typical aura (MA). Due to the rarity of FHM, traditional population-based methods were not feasible. Therefore, the search strategy employed a computer search of the National Patient Register, screening >27 000 case records from headache clinics and private neurologists, and advertisements. A total of 147 affected FHM patients from 44 families were identified. FHM patients most often had all four 'typical' aura symptoms (visual, sensory, aphasic and motor symptoms) and all had at least two of these aura symptoms during FHM attacks. The motor, sensory and visual aura symptoms were all similar in type to the motor, sensory and visual aura symptoms in MA, but FHM had a statistically significantly longer duration of the visual and sensory aura symptoms, and these and other aura symptoms often fulfilled the criteria of the International Headache Society for prolonged aura. In addition, 69% had basilar migraine (BM) symptoms during FHM attacks. The order of the aura symptoms was usually visual, followed by sensory, aphasic, motor and, lastly, basilar-type migraine symptoms. Headache was present in 99% of FHM patients during FHM attacks, whereas the aura symptoms more often occurred without headache in MA. Headache duration was significantly longer in FHM compared with MA. Based on these data, we suggest more precise diagnostic criteria for FHM and a more clear clinical distinction between FHM and BM. Our results have significant implications for case finding in genetic studies and for clinical migraine differential diagnosis.

An epidemiological survey of hemiplegic migraine

The objective of the present study was to use systematic nation-wide case-finding methods to establish the prevalence and sex ratio of hemiplegic migraine (HM) in the entire Danish population of 5.2 million inhabitants. Affected patients were identified from three different recruitment sources: the National Patient Register, case records from private practising neurologists and advertisements. Based on the observed number of affected patients from each case-finding method, it was attempted to estimate the total number of affected patients by means of the statistical method known as capture-recapture. Two hundred and ninety-one affected patients were identified; 147 were familial HM from 44 different families, 105 were sporadic HM and 39 were unclassifiable HM. The HM sex ratio (M:F) was 1:3. Based on the identified number of affected patients the prevalence of HM at the end of 1999 was estimated to be 0.01% in Denmark, where the familial and sporadic form were equally frequent.

[Molecular genetic findings in migraine]

This review focuses on the different molecular genetic findings in migraine. Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura, which is inherited as an autosomal dominant. Half the cases of FHM are caused by point mutations in the CACNA1A gene on the short arm of chromosome 19 (19p). The gene encodes a calcium ion channel. Other mutation types cause episodic ataxia 2 (EA-2). Expansions of the CAG repeat in the 3' end bring about spinocerebellar ataxia 6 (SCA 6). Some families with FHM link to loci on the long arm of chromosome 1 (1q). The genes have not yet been identified. Some families neither link to 1q nor to 19p. Population-based family and twin studies have shown that migraine both with and without aura have a multifactorial inheritance. The CACNA1A gene may be of importance for ordinary forms of migraine in a few families. Mutations in genes on the X chromosome, dopamine receptor genes, and the ACE gene appear to be involved in migraine in a few families, whereas genes for nitric oxide synthase, serotonin receptors, and mitochondrial DNA do not seem to be involved. The positive associations have not been reproduced in other studies and therefore they should be interpreted with care. It is to be hoped that in the next few years much more will be known about the molecular genetic mechanisms of migraine with and without aura. FHM is an ion channel disorder, and many factors suggest that migraine is also an ion channel disorder, which is consistent with the paroxysmal nature of the illness.

Genetics of migraine without aura, migraine with aura, migrainous disorder, head trauma migraine without aura and tension-type headache

This review is a tribute to Professor Jes Olesen involvement in the genetics of migraine and tension-type headache as it is coming up to his 60th birthday.

Increased familial risk of cluster headache

The authors studied the occurrence of cluster headache in the families of 220 Italian patients with cluster headache. A positive family history was found in 20% (44/220) of the families. Compared with the general population, first-degree relatives had a 39-fold significantly increased risk of cluster headache. Second-degree relatives had an eightfold significantly increased risk. The increased familial risk strongly supports the hypothesis that cluster headache has a genetic component in some families.