Peter Mattsson

Placebo Response in Clinical Randomized Trials of Analgesics in Migraine

The objective was to assess the placebo response in randomized clinical trials of analgesics in the treatment of migraine attacks. We included placebo-controlled studies that used the criteria of the International Headache Society for the diagnosis of migraine and headache response as the primary efficacy parameter. In the 11 studies that qualified for inclusion, headache response occurred after placebo treatment in 7-50% of the migraineurs with an average placebo response rate of 30% (95% confidence interval (CI) 23-36). Two hours after treatment with placebo an average of 9% (95% CI 7-12, range 7-17%) of the patients were found to be pain free. In conclusion, the average headache response rate to placebo was 30% in randomized clinical trials of analgesics in migraine with a tremendous variation among studies. Placebo response rates vary with the choice of primary efficacy measure as well as patient characteristics and study design.

Migraine headache and obesity in women aged 40–74 years: a population‐based study

This study investigates the associations between obesity and migraine. A neurologist clinically assessed 684 women aged 40–74 years attending a population-based mammography screening programme. Body height and weight were measured and body mass index (BMI) calculated. Obesity was defined as a BMI ≥ 30 kg/m2. The proportion of obesity did not differ between women with active migraine, women with inactive migraine or women who had never experienced migraine (P = 0.96). The distribution of frequency, intensity, duration or severity of attacks did not differ between obese and non-obese women with migraine. In this study there were no significant associations between migraine or migraine characteristics on the one hand and obesity on the other.

The prevalence of migraine in women aged 40–74 years: a population‐based study

The objective of this study was to investigate the age-dependence of the prevalence and characteristics of migraine headache and migraine visual aura. A neurologist interviewed 728 women attending a mammography screening programme. International Headache Society (IHS) criteria were used. The lifetime prevalence of migraine headache was 31.5% and the 1-year prevalence 18.0%. The magnitude of the decline of the prevalence of active (one or more attacks in the previous year) migraine headache was estimated to 50% per decade. The prevalence of active migraine visual aura was 3.8%. This did not vary by age. Except for the pain intensity and the presence of nausea, other characteristics and concomitant symptoms did not change with age. Active migraine headache and migraine visual aura in middle-aged and older women are common and modified differently by age. We suggest that the decline of prevalence of active migraine headache with age is caused by a decrease in pain intensity.

Physical fitness, but not muscle strength, is a risk factor for death in amyotrophic lateral sclerosis at an early age

Background Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disorder mainly characterised by motor symptoms. Extensive physical activity has been implicated in the aetiology of ALS. Differences in anthropometrics, physical fitness and isometric strength measured at 18–19 years were assessed to determine if they are associated with subsequent death in ALS. Method Data on body weight and height, physical fitness, resting heart rate and isometric strength measured at conscription were linked with data on death certificates in men born in 1951–1965 in Sweden (n=809 789). Physical fitness was assessed as a maximal test on an electrically braked bicycle ergometer. Muscle strength was measured as the maximal isometric strength in handgrip, elbow flexion and knee extension in standardised positions, using a dynamometer. Analyses were based on 684 459 (84.5%) men because of missing data. A matched case control study within this sample was performed. The population was followed until 31 December 2006, and 85 men died from ALS during this period. Results Weight adjusted physical fitness (W/kg), but not physical fitness per se, was a risk factor for ALS (OR 1.98, 95% CI 1.32 to 2.97), whereas resting pulse rate, muscle strength and other variables were not. Conclusions Physical fitness, but not muscle strength, is a risk factor for death at early age in ALS. This may indicate that a common factor underlies both fitness (W/kg) and risk of ALS.

Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time 1H magnetic resonance spectroscopy (MRS) study

Background: Age- and sex-related changes of metabolites in healthy adult brains have been examined with different 1H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T1 and T2 relaxation effects and makes it possible to measure metabolites with short T2 relaxation times. Purpose: To examine the effect of age on the metabolite concentrations measured by 1H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE). Material and Methods: Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification. Results: Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations. Conclusion: The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on 1H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each 1H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people.

A 3-year follow-up of headache diagnoses and symptoms in Swedish schoolchildren

Information is sparse concerning the incidence and prognosis of headache in children from the general population, especially of tension-type headache. In this study, headache diagnoses and symptoms were reassessed in 122 out of 130 schoolchildren after 3 years. Nearly 80± of those with headache at first evaluation still reported headache at follow-up. Although the likelihood of experiencing the same headache diagnosis and symptoms was high, about one-fifth of children with tension-type headache developed migraine and vice versa. Female gender predicted migraine and frequent headache episodes predicted overall headache at follow-up. The estimated average annual incidence was 81 and 65 per 1000 children, for tension-type headache and migraine, respectively. We conclude that there is a considerable risk of developing and maintaining headache during childhood. Headache diagnoses should be reassessed regularly and treatment adjusted. Girls and children with frequent headache have a poorer prognosis and therefore intervention is particularly important in these groups.

Migraine, major depression, panic disorder, and personality traits in women aged 40–74 years: a population‐based study

This study investigates the associations between migraine on the one hand and lifetime major depression, lifetime panic disorder, and neuroticism evaluated using the Swedish universities Scales of Personality on the other. A neurologist clinically assessed 728 women aged 40-74 years attending a population-based mammography screening programme. The associations between lifetime migraine and personality traits and psychiatric disorders were insignificant in multivariable analysis. However, in old women (60-74 years) the risk for active migraine was strongly associated with a history of major depression and high levels of stress susceptibility and somatic trait anxiety. Furthermore, in old women, high levels of stress susceptibility and somatic trait anxiety were associated with low ratings of migraine pain intensity and lower levels of these traits with high ratings after controlling for disability during migraines, whereas there were only small differences in middle-aged women. The results suggest that certain aspects of neuroticism are important mental correlates of the ability of old women to endure migraine pain.

Incomplete hippocampal inversion-is there a relation to epilepsy?

Incomplete hippocampal inversion (IHI) has been described in patients with epilepsy or severe midline malformations but also in nonepileptic subjects without obvious developmental anomalies. We studied the frequency of IHI in different epilepsy syndromes to evaluate their relationship. Three hundred patients were drawn from the regional epilepsy register. Of these, 99 were excluded because of a disease or condition affecting the temporal lobes or incomplete data. Controls were 150 subjects without epilepsy or obvious intracranial developmental anomalies. The coronal MR images were analysed without knowledge of the clinical data. Among epilepsy patients, 30% had IHI (40 left-sided, 4 right-sided, 16 bilateral). Of controls, 18% had IHI (20 left-sided, 8 bilateral). The difference was statistically significant (P < 0.05). Of temporal lobe epilepsy (TLE) patients, 25% had IHI, which was not a significantly higher frequency than in controls (P = 0.34). There was no correlation between EEG and IHI laterality. A total of 44% of Rolandic epilepsy patients and 57% of cryptogenic generalised epilepsy patients had IHI. The IHI frequency was very high in some epileptic syndromes, but not significantly higher in TLE compared to controls. No causality between TLE and IHI could be found. IHI can be a sign of disturbed cerebral development affecting other parts of the brain, maybe leading to epilepsy.

Incomplete inversion of the hippocampus— a common developmental anomaly

Incomplete inversion of the hippocampus, an imperfect fetal development, has been described in patients with epilepsy or severe midline malformations. We studied this condition in a nonepileptic population without obvious developmental anomalies. We analyzed the coronal MR images of 50 women and 50 men who did not have epilepsy. Twenty of them were healthy volunteers and 80 were patients without obvious intracranial developmental anomalies, intracranial masses, hydrocephalus or any condition affecting the temporal lobes. If the entire hippocampus (the head could not be evaluated) were affected, the incomplete inversion was classified as total, otherwise as partial. Incomplete inversion of the hippocampus was found in 19/100 subjects (9 women, 10 men). It was unilateral, always on the left side, in 13 subjects (4 women, 9 men): 9 were of the total type, 4 were partial. It was bilateral in six subjects (five women, one man): four subjects had total types bilaterally, two had a combination of total and partial types. The collateral sulcus was vertically oriented in all subjects with a deviating hippocampal shape. We conclude that incomplete inversion of the hippocampus is not an unusual morphologic variety in a nonepileptic population without other obvious intracranial developmental anomalies.

Headache caused by drinking cold water is common and related to active migraine

The primary aim of this study was to estimate the prevalence of cold-induced headache and to test if it is associated with migraine. Women attending a population-based mammography screening programme were asked to participate in the study. Fifty-one of 669 women (7.6%) experienced a headache after ingesting 150 ml of ice-cold water through a straw. Women who had experienced one or more migraine attacks in the last year (active migraine) were twice as likely to experience a headache from ingesting the cold water as women who had never suffered from migraine. Ninety-five women who had experienced their most recent migraine attack more than 1 year ago (inactive migraine) were not at increased risk. The prevalence of active and inactive migraine was 19.4 and 14.2%, respectively. Headache caused by drinking cold water is common in women. The results indicate that active migraine facilitates the perception of forehead pain induced by a cold palatal stimulus.