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M B Russell

Publications and source records attributed to M B Russell.

At least 19 recordsLinked to original sources
PubMed2006

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.

Adolescent↗
PubMed2006

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.

Adolescent↗
PubMed2006

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.

Charcot-Marie-Tooth Disease↗
PubMed2005

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.

Adult↗
PubMed2004

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.

Adolescent↗
PubMed2003

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.

Adolescent↗
PubMed2003

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.

Adolescent↗
PubMed2002

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.

Advertising↗
PubMed2002

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.

Adolescent↗
PubMed2001

[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.

Calcium Channels↗
PubMed2001

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.

Adult↗
PubMed2001

Is the genetic liability in multifactorial disorders higher in concordant than discordant monozygotic twin pairs? A population-based family twin study of migraine without aura.

Migraine without aura (MO) is a multifactorial disorder. Expression of a disorder with multifactorial inheritance depends on the genetic liability and on environmental factors. A high liability is reflected by a high frequency of affected relatives. We have previously shown that monozygotic (MZ) twin pairs have a significant higher concordance of MO than dizygotic twin pairs. The incomplete concordance among MZ twin pairs may be due to a lower genetic liability among discordant than concordant MZ twin pairs. The present study analysed the genetic liability in MZ twin pairs concordant and discordant for MO by the population-relative risk of MO among parents and siblings. The twin pairs were from the population-based Danish Twin Register. First-degree relatives of 29 concordant and 34 discordant MZ twin pairs were blindly telephone interviewed by a physician. The participation rate of the eligible first-degree relatives was 96%. The population-relative risk of MO among parents and siblings was 2.73 (2.39-3.06) in concordant and 2.37 (2.03-2.71) in discordant MZ twin pairs. The relative risk of MO was significantly higher in female first-degree relatives of concordant than of discordant MZ male and female twin pairs. An opposite effect was observed in male first-degree relatives, although this was not significant for male first-degree relatives of female MZ twin pairs. The present study found no statistically significant difference in genetic liability to MO among concordant and discordant MZ twin pairs. However, a difference in genetic liability among MZ and DZ twin pairs is anticipated to be small. Thus, it may be possible to show the effect in a larger study population or by investigating a more frequent trait than MO.

Adolescent↗