The G1246A Polymorphism in the Hypocretin Receptor 2 Gene is not Associated with Treatment Response in Cluster Headache

The risk of cluster headache (CH) is associated with the G-allele of the G1246A polymorphism in the hypocretin receptor 2 ( HCRTR2) gene. First-line medication is effective in only about 70-80% of CH patients. We hypothesized that the HCRTR2 G1246A polymorphism is also of pharmacogenetic relevance in CH and may affect treatment response. We performed a prospective cohort study among 184 unrelated White CH patients. While the HCRTR2 1246G allele was significantly associated with CH in this group, treatment outcomes with triptans, oxygen, verapamil and corticosteroids remained unaffected. Our results do not support a role of the HCRTR2 G1246A polymorphism in drug responses in CH.

Predictors of Hazardous Alcohol Consumption among Patients with Cluster Headache

The purpose of this study was to identify predictors of hazardous alcohol consumption in patients with cluster headache (CH). We investigated 246 German CH patients with the Alcohol Use Disorders Identification Test (AUDIT). The average daily alcohol consumption was 6.5 g. Predictors for hazardous drinking (AUDIT ≥ 5 points; 21.5% of patients) were male gender [odds ratio (OR) 4.15, 95% confidence interval (CI) 1.35, 12.71], episodic as opposed to chronic CH (OR 4.8, 95% CI 1.38, 16.67) and a low demanding job as opposed to a high demanding job (OR 2.28, 95% CI 1.15, 4.51). Our data indicate that CH patients drink less alcohol compared with the German population and that CH seems to protect against hazardous alcohol consumption. Moreover, predictors for hazardous alcohol consumption in CH patients are not different from the general population.

Telomere length and Parkinson's disease in men: a nested case-control study

BACKGROUND AND PURPOSE

Telomere shortening has been implicated in neurodegenerative disorders. However, available data on the association between telomere length and Parkinson's disease (PD) are inconclusive.

METHODS

A nested case-control design was used amongst men participating in the prospective Physicians' Health Study. A large proportion of participants provided blood samples in 1997 and they were followed through 2010. Men with self-reported PD were age-matched to controls in a 1:2 ratio. Quantitative PCR was used to determine the telomere repeat copy number to single gene copy number ratio (TSR) in genomic DNA extracted from peripheral blood leukocytes. TSR was used as a measure for relative telomere length (RTL) in our analyses. Conditional logistic regression was used to determine the risk of PD associated with RTL.

RESULTS

Data on RTL were available from 408 cases and 809 controls. Median TSR was shorter in controls than in cases (47.7 vs. 50.2; P = 0.02). The age-adjusted odds ratio (OR) for PD was 0.66 [95% confidence interval (CI) 0.46-0.95; Ptrend over quartiles 0.02] comparing the lowest to the highest quartile. The pattern of association was unchanged when comparing RTL below versus above the median (age-adjusted OR 0.75; 95% CI 0.59-0.96). Associations were similar after additional adjustment for many covariates.

CONCLUSION

Contrary to what was expected, in this large nested case-control study amongst men shorter telomeres were associated with reduced PD risk. Future research on the nature of this counterintuitive association is warranted.

Telomere length and ischaemic stroke in women: a nested case-control study

BACKGROUND AND PURPOSE

Telomere shortening has been implicated in cardiovascular disease (CVD). However, prospective data on the association between relative telomere length (RTL) and ischaemic stroke are scarce and inconclusive.

METHODS

We used a nested case-control design among women participating in the prospective Nurses' Health Study. Participants provided blood samples in 1990 and were followed till 2006. Women with confirmed incident ischaemic stroke were matched to controls by age, smoking, postmenopausal status and postmenopausal hormone use. Quantitative polymerase chain reaction was used to determine RTL in genomic DNA extracted from peripheral blood leukocytes. Conditional logistic regression was used to determine the risk of ischaemic stroke associated with RTL, using RTL quartiles and as dichotomous according to the median.

RESULTS

Data on RTL were available from 504 case-control pairs. Results did not suggest an association between RTL and ischaemic stroke. The odds ratio (OR) for ischaemic stroke was 0.82 [95% confidence interval (CI) 0.52-1.32] comparing lowest with the highest RTL quartile and 0.90 (95% CI 0.65-1.24) comparing RTL below the median with RTL above the median. Associations were unchanged after additional adjustment for cardiovascular risk factors. Further analyses suggested an association between RTL and fatal ischaemic stroke (54 case-control pairs; lowest versus highest quartile OR = 1.99, 95%CI 0.26-14.9); however, results were statistically insignificant.

CONCLUSION

In this large nested case-control study among women RTL was not associated with ischaemic stroke. In light of the varying study results in the literature on the association between telomere length and stroke, additional research is warranted.

Multiple sclerosis and restless legs syndrome: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) has been reported to occur more frequently in patients with multiple sclerosis (MS) than in people without MS.

METHODS

Systematic review and meta-analysis of studies investigating RLS in patients with MS published through April 2012. We calculated the prevalences and 95% confidence intervals (CIs) of RLS in patients with MS and people without MS as well as odds ratios (ORs) and 95% CIs of the association between MS and RLS based on data from the publications. We then calculated pooled effect estimates for the association between MS and RLS.

RESULTS

We identified 24 studies. RLS prevalence amongst patients with MS ranged from 12.12% to 57.50% and from 2.56% to 18.33% amongst people without MS. Heterogeneity amongst studies was high (RLS prevalence in patients with MS I(2) =94.4%; RLS prevalence amongst people without MS I(2) =82.2%). Hence, we did not pool the prevalence data for meta-analysis. Heterogeneity amongst studies investigating the association between MS and RLS was moderate (I(2) =53.6%). Pooled analysis indicates that MS is associated with a fourfold increased odds for RLS (pooled OR=4.19, 95% CI 3.11-5.66). This association was smaller amongst studies published as full papers (pooled OR=3.94, 95% CI 2.81-5.54) than amongst studies published as abstracts only (pooled OR=6.23, 95% CI 3.25-11.95).

CONCLUSION

This systematic review indicates that RLS prevalence amongst patients with MS ranges from 12.12% to 57.50% in different populations. Pooled analysis further indicates that the odds of RLS amongst patients with MS are fourfold higher compared to people without MS.

MTHFR 677C->T and ACE D/I polymorphisms and migraine attack frequency in women

Data on the association of the MTHFR 677C→T and ACE D/I polymorphisms with migraine severity, measured by attack frequency, are scarce. We performed an association study among 24 961 women participating in the Women's Health Study. Migraine, aura status and attack frequency were self-reported. Multinomial logistic regression was used to investigate the genotype-migraine association. Among the 3186 migraineurs with complete genotype and attack frequency data, 1270 reported migraine with aura (MA) (attack frequency 76 ≥ weekly; 219 monthly; 123 every other month; 852 fewer than six times/year) and 1916 migraine without aura (MoA) (attack frequency: 85 ≥ weekly; 414 monthly; 208 every other month; 1209 fewer than six times/year). The MTHFR 677TT genotype was associated with a reduced risk for MA, which only appeared for attacks fewer than six times/year (age-adjusted odds ratio 0.78; 95% confidence interval 0.61, 0.99). We did not find a specific pattern of association of the ACE D/I polymorphism with attack frequency for MA or MoA.

[What is migraine?]

Migraine is a multifactorial and heterogeneous disorder. Diagnostic criteria have been established by the International Headache Society, however these are only supportive in terms of definition. The pathophysiology involves neuronal and vascular phenomena. The former is supported by the cortical spreading depression being the aura correlate and by brainstem and hypothalamic activation during the pain phase; the latter is suggested by the association between migraine and cardiovascular disease and findings of pathological vasoreactivity and endothelial dysfunction. Triptans and calcitonin gene-related peptide receptor antagonists show only a relative migraine-specific action; up to 30% of patients are nonresponders. Despite a clear genetic component, the discovery of specific genes for common forms of migraine remains elusive. Electrophysiological studies consistently indicate a characteristic "dyshabituation" concurring with clinical features of altered sensory perception. The age- and sex-specific pattern along with the effect of external factors on the course of migraine argue in favor of the involvement of epigenetic mechanisms. Knowledge about migraine is still limited, which hampers a definition.

Agreement of self-reported migraine with ICHD-II criteria in the Women's Health Study

Migraine is a common headache disorder that is increasingly being evaluated in population-based studies. The American Migraine Study II and the Women's Health Study (WHS) have successfully used 'modified' International Classification of Headache Disorders, 1st edition (ICHD-I) criteria to classify patients. Investigating agreement of self-reported migraine in large epidemiological studies with the criteria of the revised version [International Classification of Headache Disorders, 2nd edition (ICHD-II)] is sparse. We have investigated 1675 women with self-reported migraine participating in the WHS, who provided additional information on a detailed migraine questionnaire that allowed us to apply all ICHD-II criteria. In this sub-cohort, we confirmed self-reported migraine in > 87% of women when applying the ICHD-II criteria for migraine (71.5%) and probable migraine without aura (16.2%). In conclusion, there is excellent agreement between self-reported migraine and ICHD-II-based migraine classification in the WHS. In addition, questionnaire-based migraine assessment according to full ICHD-II criteria in large population-based studies is feasible.

ACE D/I polymorphism, migraine, and cardiovascular disease in women

BACKGROUND

Interrelationships among the ACE deletion/insertion (D/I) polymorphism (rs1799752), migraine, and cardiovascular disease (CVD) are biologically plausible but remain controversial.

METHODS

Association study among 25,000 white US women, participating in the Women's Health Study, with information on the ACE D/I polymorphism. Migraine and migraine aura status were self-reported. Incident CVD events were confirmed after medical record review. We used logistic regression to investigate the genotype-migraine association and proportional hazards models to evaluate the interrelationship among genotype, migraine, and incident CVD.

RESULTS

At baseline, 4,577 (18.3%) women reported history of migraine; 39.5% of the 3,226 women with active migraine indicated aura. During 11.9 years of follow-up, 625 CVD events occurred. We did not find an association of the ACE D/I polymorphism with migraine or migraine aura status. There was a lack of association between the ACE D/I polymorphism and incident major CVD, ischemic stroke, and myocardial infarction. Migraine with aura doubled the risk for CVD, but only for carriers of the DD (multivariable-adjusted relative risk [RR] = 2.10; 95% CI = 1.22-3.59; p = 0.007) and DI genotype (multivariable-adjusted RR = 2.31; 95% CI = 1.52-3.51; p < 0.0001). The risk was not significant among carriers of the II genotype, a pattern we observed for myocardial infarction and ischemic stroke.

CONCLUSIONS

Data from this large cohort of women do not suggest an association of the ACE deletion/insertion (D/I) polymorphism with migraine, migraine aura status, or cardiovascular disease (CVD). The increased risk for CVD among migraineurs with aura was only apparent for carriers of the DD/DI genotype. Due to limited number of outcome events, however, future studies are warranted to further investigate this association.

Migraine, allodynia, and implications for treatment

Allodynia--perception of pain from non-noxious stimuli--is a common clinical feature in various pain syndromes. The significance for migraine has increasingly been recognized and the pathophysiology has been investigated in detail. Allodynia is a marker for sensitization of central trigeminal neurons. Intensity and persistence of allodynic symptoms are a function of duration of migraine attacks, frequency of attacks, and migraine history. It has been hypothesized that treatment success with triptans may be severely impaired in the presence of allodynia. However, randomized controlled trials did not confirm that. Treatment with cyclooxygenase inhibitors and dihydroergotamine does not seem to be limited by allodynia; these medications may be able to reverse allodynia. Data on the new class of calcitonin-gene related-peptide antagonists are not yet available. Additional and more refined randomized controlled trials, focusing on methodological issues pertaining to the determination of allodynia, are warranted to resolve the true relationship between allodynia and treatment response. Regardless--based on available randomized controlled trials--the recommendation prevails to initiate abortive treatment as soon as possible after attack onset when pain is still mild.

Long-term outcome of Guillain-Barré syndrome

OBJECTIVES

To investigate long-term neurological residua after Guillain-Barré syndrome (GBS) and to evaluate the predictive value of respiratory insufficiency during the acute stage of the disease.

METHODS

Thirty-four patients with GBS including 5 patients with Miller-Fisher syndrome admitted to a university hospital between 1994 and 2002 underwent a neurological and electrophysiological follow-up examination 7 - 86 months after onset of GBS.

RESULTS

Of the 34 patients, 5 patients had completely recovered, 11 patients demonstrated mild residual symptoms and/or signs, and 18 patients presented with functionally relevant neurological deficits predominantly in the lower extremity, although all patients could walk without assistance and none showed respiratory failure. Nerve conduction studies revealed abnormal findings in 30 patients. Autonomic function testing of the cardiovascular system showed a pathological blood pressure response to standing in 27 of 33 patients. No association was found between the course of the disease and sleep-disordered breathing at follow-up. Age at onset, need for mechanical ventilation, and duration of the plateau phase correlated with severity of neurological residua at follow-up.

CONCLUSIONS

There was a high persistence of residual sensorimotor signs and symptoms after GBS in our cohort. In addition, abnormal blood pressure declines not associated with clinically overt orthostatic dysregulation were detected in the majority of our patients at follow-up. This is in contrast to previous reports describing a gradual improvement of autonomic dysfunction after 2 - 18 months. A combined prognostic score based on patient age, duration of the plateau phase, and ventilatory failure in the acute stage of GBS might predict the long-term outcome.

G Protein β3 Polymorphism and Triptan Response in Cluster Headache

Only about 70% of migraine and cluster headache (CH) patients report significant treatment responses to triptans, which are agonists at 5-HT(1B/D) receptors belonging to the family of G protein-coupled receptors. We analyzed whether a common polymorphism in the gene for the G protein beta3 subunit (GNB3 C825T) modulates responder rates to triptans among a cohort of 231 unrelated Caucasian CH patients. A total of 180 CH patients used triptans, of whom 71.1% reported treatment success. The adjusted odds ratio for treatment response to triptans for heterozygous carriers of the GNB3 825T allele was 2.96 (95% confidence interval 1.34-6.56; P=0.0074) vs carriers of the 825CC genotype. The GNB3 genotype status did not affect responses to other acute and preventive therapeutic regimes including oxygen, verapamil, and corticosteroids, i.e., drugs not directly affecting G proteins. We conclude that pain relief by triptans is significantly modulated by a common genetic GNB3 variant.

Cluster headache is associated with the G1246A polymorphism in the hypocretin receptor 2 gene

The G1246A polymorphism in the gene of the hypocretin receptor 2 (HCRTR2) has been linked to the risk for cluster headache (CH). The authors examined this association in a large sample of 226 patients with CH and 266 controls from Germany. The genotype and allele distribution varied significantly between patients and controls. Homozygous carriers of the G-allele had a twofold increase in risk for CH (OR 1.97; 95% CI 1.32 to 2.92; p = 0.0007).

Naltrexone Treatment of Combined Alcohol and Opioid Dependence: Deterioration of Co-morbid Major Depression

Naltrexone is frequently used for the treatment of opioid or alcohol dependence. However, the reports on its potential to worsen affective disorders are contradicting. Here we report on a patient with combined alcohol and opioid dependence whose co-morbid major depression deteriorated reversibly and repeatedly under naltrexone. By exchanging buprenorphine for naltrexone, his depression and craving for alcohol and opioids disappeared. This underlines the close interaction between depression, substance dependence and the opioid system.

Development and applications of 4-D ultrasound (dynamic 3-D) in neurosonology

The development and application of color-coded data in three-dimensional (3-D) reconstruction or four-dimensional (4-D) imaging (equal to dynamic 3-D) are demonstrated. In 4-D imaging, electrocardiography-triggered data acquisition of consecutive phases during the heart cycle are stored to form a multiphase 3-D data set. The option of color-coded data gives a new insight into such hemodynamic information. In the past, 3-D reconstructions were simple unicolor images, as in power mode, and the color-coded hemodynamic information was lost. These new options are presented here, along with color-coded data in examples of angiographically controlled pathologic results in extracranial and intracranial vessels.