Comparison of Contingent Negative Variation Between Migraine Interval and Migraine Attack Before and After Treatment With Sumatriptan

SYNOPSIS
We compared in a placebo controlled, double blind, cross-over within-subject design, the amplitude and area integral of contingent negative variation (CNV) using a 2 second interstimulus interval in migraine patients between attack and interval before and after treatment. The study was conducted on 14 female subjects suffering from migraine without aura. The measurements were performed in a balanced sequence at four different times on each patient, twice during the migraine interval and once in each of two migraine attacks. The CNV in the patients was measured first (baseline), then medication was administered on a double-blind basis with an auto-injector, using either 6 mg sumatriptan or a placebo solution. Thirty minutes after administration the CNV parameters were measured again and the changes between pre-and post-treatment were taken as dependent variables. CNV amplitude baseline readings did not differ significantly between the four conditions, Neither administration of placebo nor sumatriptan led to a significant change in CNV parameters independent of whether significant clinical improvement of migraine headache occurred or not. According to our findings CNV-mechanisms between attack and interval are not subject to short-term changes, even though a small, not significant tendency towards · decrease in CNV amplitude during migraine attacks appears to exist. Therefore, it can be assumed that changes in the systems which are depicted by CNV readings are not involved in initiating and terminating acute migraine attacks.     

Perimenstrual Migraine: Effect of Estraderm TTS(r) and the Value of Contingent Negative Variation and Exteroceptive Temporalis Muscle Suppression Test

SYNOPSIS
In 20 patients with pure menstrual migraine either Estraderm TTS 50° patches (E) or placebo (P) patches were applied during three successive menstrual cycles, randomly allocated to the treatment sequences E-P-E or P-E-P. Clinical neurophysiological tests, contingent negative variation (CNV) and exteroceptive temporalis muscle suppression test (ETST) were performed before treatment. The predictive value of these tests regarding the efficacy of Estraderm TTS was studied.
Neither the number, duration and severity of the migraine attacks, nor the consumption of analgesics and ergotamine differed significantly during Estraderm TTS and placebo treatment.
The ETST was consistent with migraine in 35% (95% confidence interval 15.4 to 59.2) of the patients. The CNV in 55% (31.5 to 76.9), and both tests in 25% (8.7 to 49.1%).
Regarding the prediction of the Estraderm TTS effect on the migraine attacks, the specificity of the ETST, CNV and the combination of ETST with CNV, calculated for the first two cycles, was respectively 81.8% (48.2 to 97.7), 45.5% (16.8 to 76.6) and 80% (28.4 to 99.5). For the last two cycles these values were respectively 75% (42.8 to 94.5), 50.0% (21.1 to 87.9) and 71.4% (29.0 to 96.3). The sensitivity of the tests was respectively 62.5% (24.5 to 91.5), 62.5% (24.5 to 91.5) and 66.7% (22.3 to 95.7) in the first 2 cycles. In the last 2 cycles 50.0% (15.1 to 84.3), 62.5% (24.5 to 91.5) and 60% (14.7 to 94.7).
This study did not demonstrate an effectiveness of Estraderm TTS in perimenstrual migraine, except for the subgroup of perimenstrual migraine patients in whom the ETST test results were consistent with migraine.     

Seasonal Variation of Migraine in an Arctic Population

Objectives.— To investigate seasonal variation of migraine headache in a population residing in an extreme Arctic locale.
Background.— Exposure to light may trigger migraine attacks and patients may also be hypersensitive to light between the attacks. In previous studies of migraine in Northern latitudes we have demonstrated that patients with migraine experience more attacks in the summer. In order to confirm this finding and gain more insight into a possible north-south effect of seasonal migraine variation, we performed a population-based study in Svalbard, which is one of the northernmost populated areas of the world.
Method.— A postal questionnaire was mailed to all inhabitants aged 12 years or older living in Svalbard and the migraine diagnosis made by a structured telephone interview.
Results.— Of a total of 1569, 1029 (66%) returned the questionnaire. Of them, 184 (18%) experienced headache within the recent year prior to the study that could not be explained by alcohol, trauma, or viral infections. Eighty-eight individuals had migraine according to the revised criteria set by the International Headache Society. Nineteen (22%) reported seasonal variation of migraine. Ten (12%) experienced more migraine in the light season, while 9 (10%) got worse in the dark season. No differences in proportions of migraine with aura (MA) and migraine without aura (MO) could be detected. Also, the frequency of MA patients who used sunglasses to avoid migraine headache was nonstatistically increased compared with MO.
Conclusion.— There was no indication of more seasonal variation of headache in a population of otherwise healthy people with migraine living in an extreme Arctic area with long periods of midnight sun and polar nights with complete darkness. The strength of conclusion, however, is significantly limited by a low response rate and small sample size.     

Sustained Visual Aura: A Totally New Variation of Migraine

An unusual case of an abnormally long-lasting (over 12 months) visual migraine aura is reported. The absence of signs of a structural lesion, as shown by neuro-imaging and clinical investigations, make difficult the differential diagnosis between a new variation and a complication of migraine.     

Variation of Plasma Free Tryptophan and CSF 5-HIAA During Migraine

SYNOPSIS
Simultaneous plasma free and total tryptophan and CSF 5-HIAA concentrations were determined in 18 migraine patients during headache-free intervals, four hours and 24 hours after onset of headache. A statistically significant (p<0.05) positive correlation was found between CSF 5-HIAA and plasma free tryptophan 4 hours after onset of headache. No other statistically significant correlations were noted. Increased catecholamines resulting from stress (of migraine attack) can cause elevation of unesterified fatty acids which displace tryptophan from its binding to plasma albumin, making free tryptophan available to the brain for serotonin metabolism. The increased CSF 5-HIAA during the attack of migraine is related to stress, rather than to pathogenetic factors in the disorder.     

Relationship of Intersession Variation in Negative Pain-Related Affect and Responses to Thermally-Evoked Pain

The purpose of this study was to determine whether session-specific measures of negative pain-related affect would account for longitudinal variability in the ratings of the evoked thermal pain. Pain-free subjects rated pain evoked on the posterior leg using thermal stimuli of 45°, 47°, 49°, and 51°C on 3 occasions, each separated by 2 weeks. Session-specific negative pain-related affect measures were also collected. Ratings of pain decreased significantly with repeated testing, demonstrating a systematic change in rating from the first to second sessions that ranged from a mean of 5.3 at 47°C to 9.1 at 49°C. In addition, large random variation occurred across all sessions, resulting in minimal detectable change ranging from 14 to 27. The least variability occurred when a mean rating of the 4 temperatures was used. Session-specific measures of pain-related affect decreased with repeated testing; however, the significant between-subject variability in both rating of pain and pain-related affect were not related to each other. No associations were identified between psychological measures and variability in rating of evoked pain. Future studies of the variability in ratings should consider other factors such as attentional focus.PerspectiveThe individual variability in thermal rating was not explained by individual variation in session-specific measures of negative pain-related affect. The results of this study support the use of repeated baseline measures of thermal stimuli when feasible. When this is not possible, the variability in ratings of thermal stimuli over multiple sessions is reduced when the mean of multiple temperatures is used.     

Migraine in women

Estradiol is an important headache modulator. After menarche, cycling estradiol significantly influences headache activity, with risk of headache decreasing as estradiol levels rise and increasing when estradiol levels fall. This study follows the life a young woman, from the onset of migraine in adolescence through menopause. This case illustrates the difficulties of correctly diagnosing migraine during childhood and adolescence, variable changes that can occur with headache during pregnancies, and the frequent exacerbation of stable headaches during the perimenopausal period when estradiol levels fluctuate. The case presentation illustrates many of the common challenges faced in caring for migraine in women.