Comparative study with EMG, pressure algometry and manual palpation in tension-type headache and migraine

According to International Headache Society classification criteria, the presence of pericranial muscle disorder in tension-type headache should be evaluated using one of the following methods: EMG, pressure algometry or manual palpation. The purpose of this study was to compare the results of these three methods in 15 patients with episodic tension-type headache, 29 with chronic tension-type headache and 22 presenting migraine without aura compared to those obtained in healthy individuals. Algometric and EMG recordings at the frontalis muscle during mental arithmetic were more impaired in episodic and chronic tension headache patients than in controls and migraine patients. Chronic tension headache patients were significantly impaired at the trapezius muscle in all three tests compared to controls. Our data indicate that when two or three tests were carried out the diagnostic capacity was significantly improved in comparison to only one test. Moreover, since a different pattern could be seen with pain and without pain, the existence of headache at the time of testing should be taken into consideration.     

Stress-induced pain and muscle activity in patients with migraine and tension-type headache

We recorded deep pain and surface electromyographic (EMG) responses to stress in 22 migraineurs during headache-free periods, 18 patients with tension-type headache (TTH), and 44 healthy controls. Sixty minutes of cognitive stress was followed by 30 min relaxation. EMG and pain (visual analogue scale) in the trapezius, neck (splenius), temporalis and frontalis areas were recorded. TTH patients had higher pain responses in temporalis and frontalis (with similar trends for trapezius and splenius) and more potentiation of pain during the test than controls. Migraine patients developed more pain in the splenius and temporalis than controls. Muscle pain responses were more regional (more pain in the neck and trapezius compared with the temporalis and frontalis) in migraine than in TTH patients. TTH patients had delayed pain recovery in all muscle regions compared with controls, while migraine patients had delayed pain recovery in a more restricted area (trapezius and temporalis). EMG responses were not different from controls in headache patients, and EMG responses did not correlate with pain responses. TTH patients had delayed EMG recovery in the trapezius compared with controls and migraine patients. These results support the concept that (probably central) sensitization of pain pathways and the motor system is important in TTH. Less pronounced and more regional (either peripheral or central) trigeminocervical sensitization seems to be important in migraine. Surface-detectable muscular activation does not seem to be causal for pain during cognitive stress either in migraine or in TTH.     

Cross-correlation between stress, pain, physical activity, and temporalis muscle EMG in tension-type headache

Thirty-six tension-type headache subjects and 36 non-headache matched controls recorded their temporalis muscle electromyographic (EMG) activity and their pain intensity, stress and physical activity levels in a daily diary. Measurements were performed every 30 min for 6 days (EMG 3 days only). A time-lagged cross-correlational analysis between pain, stress, physical activity, and EMG shows that the highest correlation coefficient values occurred between pain and stress at the same ( r =0.33) and at the two preceding 0.5 h time points ( r =0.21 and r =0.26) in the headache group. Virtually no correlation was found between pain, stress, or physical activity with EMG for either group. These data show that temporalis muscle activity levels were not related to the rise and fall of the subjects' pain or stress levels. Conversely, elevated stress appeared to be highly related to pain; it occurs as both an antecedent and simultaneous event with elevated headache pain.     

Oxidative stress and platelet responsiveness in migraine

The aim of this study is to investigate whether oxidative stress may represent a pivotal determinant of the altered functional features of platelets in migraineurs during the headache-free period. Twenty-three patients with migraine with aura, free of attack, and 23 healthy volunteers were enrolled for the study. The involvement of an oxidative condition appears confirmed by the statistically significant increase (p<0.001) of plasma levels of thiobarbiturie acid-reactive substances which may be considered a marker for oxidative stress and themselves strong pro-oxidants. Such oxidative status seems to induce in platelets of migraineurs increased membrane rigidity (p<0.001), reduced cytosolic calcium in the resting condition and after thrombin stimulation (p<0.001), and decreased aggregatory responses to ADP and collagen. These findings indicate that the "in vitro" anomalous platelet behavior in migraineurs, observed in headache-free periods, may be considered as the transient expression of the exhausted platelets to "in vivo" stimulation and probably related to an increased vulnerability to oxidative stress.     

Post-traumatic stress disorder in episodic and chronic migraine

OBJECTIVE: To assess and contrast the relative frequency of self-reported post-traumatic stress disorder (PTSD) in patients with episodic migraine and chronic/ transformed migraine. BACKGROUND: Several risk factors have been identified as risk factors for chronification of headache disorders. Childhood abuse has been suggested as a risk factor for chronic pain in adulthood. In addition depression, as well as several other psychiatric disorders, are co-morbid with migraine. Recent data suggest that PTSD may be more common in headache sufferers than in the general population. METHODS: This was a prospective, pilot study conducted at a headache center. Adult subjects with episodic, chronic, or transformed migraine were included. Demographic information, depression history, body mass index (BMI), and headache characteristics were obtained. PTSD was assessed using the life events checklist (LEC) and the PTSD checklist, civilian version (PCL-C). We contrasted the data from episodicmigraineurs and chronic/transformed migraine participants (CM) and conducted multivariate analyses, adjusting for covariates. RESULTS: Of the 60 participants included, 91.7% were female with a mean age of 41.4+/-12.5 years old. EM was diagnosed in 53.3% and CM in 46.7%. The mean BMI was not significantly different between groups. In contrast, the relative frequency of depression was significantly greater in subjects with CM (55.2%) than EM (21.9%, P=.016). There was no significant difference in the percentage of participants reporting at least 1 significant traumatic life event (LE) or in the mean number of traumatic LEs between EM and CM participants. However, the relative frequency of PTSD reported on the PCL in CM (42.9%) was significantly greater as compared to EM (9.4%, P=.0059. After adjusting for depression and other potential confounders, the difference remained significant P=.023). CONCLUSION: PTSD is more common in CM than in episodic migraineurs. This suggests that PTSD may be a risk factor for headache chronification, pending longitudinal studies to test this hypothesis.     

Cardiovascular responses to pain and stress in migraine

OBJECTIVE: The purpose of this study was to investigate how migrainous subjects and controls differ in their cardiovascular reactivity and recovery to a cognitive and an acute pain laboratory stressor. BACKGROUND: Prior research suggests that individuals subject to migraine may respond physiologically to pain and stress differently than controls. METHODS: Fifty-two women (26 with migraine and 26 controls) participated in a single laboratory session. Multiple cardiovascular responses to a cognitive (mental arithmetic) and an acute pain (cold pressor task) stressor were recorded with cardiac impedance methods. The cardiovascular responses measured included systolic and diastolic blood pressure, heart rate, cardiac output, stroke volume, and total peripheral resistance. RESULTS: Results indicated that the migrainous participants displayed different cardiovascular recovery patterns for total peripheral resistance, cardiac output, and stroke volume following the termination of the mental arithmetic task. CONCLUSIONS: These results support the hypothesis that individuals with migraine respond physiologically to stress differently than control individuals.     

Work stress and new-onset migraine in a female employee population

Mäki K, Vahtera J, Virtanen M, Elovainio M, Keltikangas-Järvinen L & Kivimäki M. Work stress and new onset migraine in a female employee population. Cephalalgia 2008; 28:18–25. London. ISSN 0333-1024
This prospective cohort study examined whether work stress, as indicated by the job strain model and the effort–reward imbalance model, predicts new-onset migraine among 19 469 female employees with no history of migraine at study entry. A baseline survey between 2000 and 2002 assessed work stress and demographic factors. Self-reported newly diagnosed migraine was measured at follow-up between 2004 and 2005 and 1281 new cases of migraine were detected. In logistic regression analysis adjusted for age, socioeconomic position and depression at baseline, no association between job strain and migraine was found. In contrast, high effort–reward imbalance was associated with slightly increased risk of migraine at follow-up, odds ratio 1.23 (95% confidence interval 1.04, 1.45). The proportion of new migraine cases attributable to high effort–reward imbalance was 6.2%. If the observed association is causal, our findings suggest that high effort–reward imbalance might function as a modifiable risk factor for new-onset migraine.     

血清瘦素在手术创伤后应激反应中的变化

目的观察手术创伤应激反应后血清瘦素（Leptin）的变化，探讨Leptin在其中的作用。方法选择不同手术方式（开腹或微创腹腔镜）切除部分肝和胆囊肿瘤患者，采用放射免疫分析法和酶联免疫吸附法（ELISA）测定两组患者不同时间血清Leptin、粒细胞集落刺激因子（G—CSF）、C-反应蛋白（CRP）和促肾上腺皮质激素（ACTH）水平变化。结果同术前相比，开腹组血清Leptin水平在术后即刻（T0）略下降，术后1d（T1）达最高峰，术后2d（T2）、4d（T4）开始低于高峰水平，但仍较术前有显著增高；而腹腔镜组血清Leptin水平变化同开腹组差异无显著性。两组患者G—CSF的变化在术后均显著下降，T1～T4仍未恢复到术前水平。两组患者血清CRP在T0略下降，但在T1～T4均明显高于术前水平。开腹组ACTH水平在T0、T1明显下降，T2开始恢复；但腹腔镜组ACTH水平术前和术后差异并无显著性。结论手术创伤应激导致患者血清Leptin浓度持续增高，但与CRP、G—CSF和ACTH水平的变化不存在相关性。     

Increased asymmetric dimethylarginine and nitric oxide levels in patients with migraine

Asymmetric dimethylarginine (ADMA) has been found as correlated with endothelial dysfunction and oxidative stress. There are few studies regarding ADMA and nitric oxide (NO) levels in patients with migraine and alterations of ADMA and NO levels during migraine attack are not well-known. Therefore, in present study, we aimed to measure NO and ADMA levels in patients with migraine and compare them with the control group to investigate the correlation between migraine, oxidative stress and endothelial dysfunction. The migraine group consisted of 59 patients, including 22 suffering from migraine with aura and 37 suffering from migraine without aura. The control group consisted of 31 healthy volunteers without headache. The patients in migraine group were divided into subgroups based on whether attack period was present or not and whether it was migraine with or without aura. Plasma ADMA levels were measured using an enzyme-linked immunosorbent assay method. Migraine patients had higher concentrations of NO (35.6±7.7, 31.0±6.2 μmol/L, respectively, p=0.005) and ADMA (0.409±0.028, 0.381±0.044 μmol/L, respectively, p = 0.001) levels when compared with the healthy controls. During migraine attack, NO and ADMA levels were found to be significantly higher in migraine group as compared to control group (respectively, p=0.015, p=0.014). Similarly, NO and ADMA levels in the patients with migraine in the interictal period were found to be significantly higher as compared to control group (p=0.011, p=0.003). In conclusion, higher ADMA and NO levels of patients with migraine supported that oxidative stress and endothelial dysfunction may have a role in migraine pathogenesis.     

Association of the Bedside Shivering Assessment Scale and derived EMG power during therapeutic hypothermia in survivors of cardiac arrest

Introduction

Shivering during therapeutic hypothermia (TH) after cardiac arrest (CA) is common, but the optimal means of detection and appropriate threshold for treatment are not established. In an effort to develop a quantitative, continuous tool to measure shivering, we hypothesized that continuous derived electromyography (dEMG) power detected by the Aspect A2000 or VISTA monitor would correlate with the intermittent Bedside Shivering Assessment Scale (BSAS) performed by nurses.

Methods

Among 38 patients treated with TH after CA, 853 hourly BSAS measurements were compared to dEMG power measured every minute by a frontal surface electrode. Patients received intermittent vecuronium by protocol to treat clinically recognized shivering (BSAS > 0). Mean dEMG power in decibels (dB) was determined for the hour preceding each BSAS measurement. dEMG and BSAS were compared using ANOVA.

Results

The median dEMG power for a BSAS score of 0 (no shivering) was 27 dB (IQR 26-31 dB), BSAS 1 was 30.5 dB (IQR 28-35 dB), BSAS 2 was 34 dB (IQR 30-38 dB), and BSAS 3 was 34.5 dB (IQR 32-44.25). The dEMG for BSAS ≥ 1 (shivering) was statistically different from BSAS 0 (p < 0.0001). dEMG and BSAS correlated moderately (r = 0.66, p < 0.001).

Conclusion

dEMG power measured from the forehead with the Aspect A2000 or VISTA monitor during therapeutic hypothermia correlated with the Bedside Shivering Assessment Scale. Given its continuous trending of dEMG power, the A2000 or VISTA may be a useful research and clinical tool for objectively monitoring shivering.     

基于肌电和惯性传感器数据融合的脑卒中患者上肢够物运动定量评估

目的:探讨融合肌电和惯性传感数据的定量化脑卒中患者上肢运动评估方法的有效性.方法:实验联合使用微型惯性传感器和多通道肌电传感器,同步采集了20例脑卒中患者(患者组)和年龄匹配的10名老年人(健康组)的肌电及运动数据,融合这两种数据分别进行了分组统计学分析和典型个例分析.结果:患者组的运动学参数与健康组比较差异有显著性意义,并且运动学参数与肌电参数之间有着较高的相关性.运动参数所反映出的异常运动模式与肌电所反映出的情况相一致,肌电数据能用于解释异常运动模式的原因.结论:本定量化康复评估方法可以实时、定量和可视化地进行临床分析和诊断治疗.     

The prophylactic effect of timolol versus propranolol and placebo in common migraine: beta-blockers in migraine

A multicentre double-blind, cross-over trial was planned to evaluate the prophylactic effect of timolol in migraine. The effectiveness of the drug was compared to propranolol and placebo. In the Norwegian part of the trial described in this paper, 18 patients completed the study. The data suggest that timolol is equivalent in effectiveness to propranolol in migraine prophylaxis. Firm conclusions should not be drawn until the results from the multicentre trial are available.     

Neuroexcitatory amino acid levels in plasma and cerebrospinal fluid during migraine attacks

A current hypothesis for migraine suggests that neuroexcitatory amino acids may participate in the triggering of attacks. To investigate this possibility we measured glutamic and aspartic acid level in plasma and cerebrospinal fluid (CSF) of patients with common and classic migraine during attacks, making comparisons with controls suffering from stress. Plasma levels of amino acids in migraine patients were lower than in controls. CSF concentrations of glutamic acid were higher in migraineurs than in controls. Our results suggest an excess of neuroexcitatory amino acids in the CNS of migraine patients during attacks, possibly favoring a state of neuronal hyperexcitability.     

大鼠应激性溃疡发病机制及其防治方法的研究

为进一步了解应激性溃疡的发病机制，寻找更有效的治疗方法。以冷束缚法制成大鼠应激性溃疡动物模型。将其分成对照组、治疗Ａ组（西米替丁组）、治疗Ｂ组（东莨菪碱组）和治疗Ｃ组（西米替丁＋东莨菪碱组），通过溃疡指教、光镜与电镜观察各组病理组织学变化。结果：治疗Ｃ组防治效果优于治疗Ａ组及Ｂ组。作者认为：在应激状态下，胃粘膜局部血循环障碍与胃内ｐＨ过低是导致损伤的重要始动因素；综合使用抑酸与促进血循环的防治方法，其效果明显优于单纯抑酸方法。     

Platelet membrane fluidity and peroxynitrite levels in migraine patients during headache-free periods

Previous investigations have suggested that changes in platelet activity may play a key role in the pathophysiology of migraine via mechanisms involving the nitric oxide (NO) pathway. Changes in platelet response and nitrite levels have recently been demonstrated during migraine attacks, while there is considerable uncertainty about NO activity in headache-free periods. A reactive oxidant produced from NO and superoxide anion at the site of inflammation, peroxynitrite (ONOO-) has effects including changes in membrane activity and fluidity. The aim of the present study was to determine ONOO- levels in the platelets of patients suffering from migraine during the headache-free period. Nitric oxide synthase (eNOS and iNOS) expression in platelets and the effects of ONOO- on membrane Na+/K+-ATPase activity and membrane fluidity were also evaluated. Subjects were 57 patients suffering from migraine without aura and 35 controls. Blood samples were collected in the headache-free period. Platelet ONOO- levels were determined using dichlorofluorescein acetate with steady-state fluorescence. Platelets were then probed for induction of eNOS and iNOS expression by western immunoblotting. Membrane Na+/K+-ATPase activity and fluidity were determined with the fluorescent probes TMA-DPH and DPH. In the presence of extracellular l-arginine(100 micromol/l), ONOO- production was significantly greater in patients' platelets than in those of controls (P < 0.001). Western immunoblotting of platelet proteins evidenced higher iNOS expression in patients than in controls. In addition, platelet membrane Na+/K+-ATPase activity and membrane fluidity evaluated by TMA-DPH were significantly lower in patients (P < 0.001). In conclusion, migraine patients show intercritic changes in platelet membrane fluidity and activity that may be related to the oxidative stress caused by increased ONOO- levels.     

β-endorphin and ACTH in plasma during attacks of common and classic migraine

Plasma levels of beta-endorphin and ACTH were measured during and outside migraine attacks in 17 patients with common migraine and 11 patients with classic migraine. Specific radioimmunoassays for beta-endorphin and ACTH were used. The beta-endorphin assay did not cross-react with beta-lipotropin. In common migraine, median plasma beta-endorphin was 3.3 pmol/l (95% confidence limits: 2.5-4.0 pmol/l) during attacks and 2.9 (2.4-3.2) pmol/l in the headache-free period. In classic migraine, plasma beta-endorphin was 3.2 (1.4-4.3) pmol/l during attacks and 2.4 (1.1-3.6) pmol/l outside attacks. ACTH plasma levels were 15 (10.5-20) pmol/l during and 15.7 (13.4-17) pmol/l outside attacks in common migraine. In classic migraine, plasma ACTH was 16 (7-36) pmol/l and 12.3 (8-28) pmol/l respectively. No significant differences were found between attacks and headache-free periods in common or classic migraine. Accordingly, we could not add evidence to the theory of a dysfunction of the endogenous opioid system in migraine.     

Post-traumatic stress disorder and migraine: epidemiology, sex differences, and potential mechanisms

Migraine is a common, often disabling disorder associated with a significant personal and societal burden. The presence of post-traumatic stress disorder (PTSD) may increase this disability substantially. Migraine and PTSD are both up to 3 times more common in women than in men. The divergence in prevalence rates of migraine and PTSD that occurs between the sexes after puberty suggests that gonadal hormones play an important role. In addition, the preponderance of PTSD in women may be related to their higher rates of interpersonal trauma, the most common cause of PTSD. However, recent data suggest that although the odds of PTSD are increased in both women and men with episodic migraine, this association is stronger in men than women. In this paper, we examine the epidemiology of PTSD and migraine, with an emphasis on the known sex differences. We then discuss the neurobiological changes associated with PTSD, the current hypotheses for the mechanisms relating PTSD and migraine, and the treatment implications of these findings.