Appraisal of Subjective Stress in Individuals with Tension-Type Headache: The Influence of Baseline Measures

These studies investigated appraisal and coping strategies of tension-type headache sufferers and headache-free controls. In study 1, 60 women engaged in an interpersonal stressor. They completed measures that assessed subjective stress and coping strategies. Headache sufferers reported greater levels of stress at baseline than did controls but were not more reactive to a stressful interpersonal situation. All participants reported greater use of disengagement coping during the interpersonal interaction, while the amount of engagement coping strategies did not differ. Participants (30 women) in Study 2 engaged in progressive muscle relaxation. Headache participants again reported higher levels of subjective stress at baseline, this difference was nearly gone following relaxation. Together, the results suggest that individuals with tension-type headache report higher levels of subjective stress than headache-free controls when they make baseline ratings of stress and that this elevation cannot be attributed to the anticipation of a future stressful event.     

A naturalistic study of the relationships among electromyographic activity, psychological stress, and pain in ambulatory tension-type headache patients and headache-free controls.

Twelve subjects who met diagnostic criteria for episodic tension-type headache and nine subjects who rarely or never suffered from headaches wore a computer-controlled electromyographic (EMG) activity recorder in their natural environment for 48 to 96 consecutive hours. EMG activity of the posterior neck or frontal muscles was recorded 24 hr per day. During waking hours, subjects rated their perceived levels of stress, pain, and negative affect at 30-min intervals. The EMG activity of headache and control subjects did not differ significantly, and EMG activity did not covary with stress, pain, or negative affect. Cross-correlations among EMG activity, pain, and stress revealed little evidence of leading, contemporaneous, or lagging relationships. Interrupted time series analysis showed no consistent muscle hyperactivity during a headache attack compared to a headache-free baseline period.     

Comparison of Frontal EMG Biofeedback and Several Types of Relaxation Instructions in Reducing Multiple Indices of Arousal

During the training phase, 96 subjects were given one of four types of relaxation instructions (single instructions, repeated instructions, relaxation training, no instructions) and in addition either did or did not receive frontal EMG biofeedback training. Results indicated that each of the instructions and biofeedback procedures were equally effective in reducing frontal EMG, but that none of these procedures had any effect on subjective anxiety or autonomic indices of arousal (pulse rate, skin temperature, and finger pulse volume). During the generalization/stress phase, subjects were threatened with electric shock and were told to apply the relaxation techniques they learned during the training phase even though no additional instructions and/ or biofeedback training would be provided. To assess the effectiveness of the shock manipulation, a no-threat control group was included. Results indicated that: a) the shock manipulation was effective in increasing arousal, b) previous instructions and/or biofeedback were equally effective in reducing frontal EMG levels, but that c) only relaxation training was consistently effective in reducing subjective and autonomic indices of arousal. These findings: a) suggest that in stressful situations, relaxation training may be more effective than either EMG biofeedback or simple relaxation instructions in producing a general relaxation effect as opposed to a specific EMG effect; and b) indicate the importance of assessing the effectiveness of relaxation procedures during stressful situations during which subjects’ levels of arousal are elevated above resting baseline levels.     

The Psychophysiological Assessment of Muscle-Contraction Headache Subjects During Headache and Nonheadache Conditions

This study evaluated multiple psychophysiological variables in muscle-contraction headache subjects during headache and nonheadache states. Nine muscle-contraction headache subjects participated in four sessions: twice when they had a headache and twice when they had no headache. During each session multiple psychophysiological measures (frontal electromyogram (EMG), neck EMG, arm EMG, cephalic blood volume pulse (BVP), and heart rate) were monitored during baseline, a cognitive stressor, a physical stressor, and post-stress adaptation phases. Baseline psychophysiological measures did not discriminate between headache conditions but there were significant differences between conditions on measures of neck and forearm EMG. Analyses of individual subjects revealed that headache states, compared to nonheadache states, were associated with significantly greater neck EMG levels and significantly greater cephalic vasodilation for most subjects. The implications of these studies for the etiology and treatment of muscle-contraction headache are discussed.     

Masseter muscle hyperactivity and myofascial pain dysfunction syndrome: A relationship under stress

Myofascial pain dysfunction syndrome (MPD) of the temporomandibular joint (TMJ) is a psychophysiological disorder that develops because of hyperactive muscles of mastication. Ten women meeting criteria for MPD and 12 symptom-free women participated in the study. The rationale for this study was to observe cardiovascular and masseter muscle changes during four contiguous experimental periods: baseline/adaptation, reaction time, recovery, and relaxation. MPD patients showed less masseter muscle activity and higher heart rates at baseline than controls. Controls had significantly higher masseter EMG activity during reaction time. Both groups showed significant elevation in masseter muscle activity and heart rate over the 14-min reaction period. MPD patients' recovery from stress was equivalent to controls' for both heart rate and masseter muscle activity. MPD patients exhibited significantly slower reaction times than controls. The results suggest that masseter muscle hyperactivity may not account for the development and maintenance of MPD.     

Alterations in cervical muscle activity in functional and stressful tasks in female office workers with neck pain

This study determined differences between computer workers with varying levels of neck pain in terms of work stressors, employee strain, electromyography (EMG) amplitude and heart rate response to various tasks. Participants included 85 workers (33, no pain; 38, mild pain; 14, moderate pain) and 22 non-working controls. Work stressors evaluated were job demands, decision authority, and social support. Heart rate was recorded during three tasks: copy-typing, typing with superimposed stress and a colour word task. Measures included electromyography signals from the sternocleidomastoid (SCM), anterior scalene (AS), cervical extensor (CE) and upper trapezius (UT) muscles bilaterally. Results showed no difference between groups in work stressors or employee strain measures. Workers with and without pain had higher measured levels of EMG amplitude in SCM, AS and CE muscles during the tasks than controls (all P < 0.02). In workers with neck pain, the UT had difficulty in switching off on completion of tasks compared with controls and workers without pain. There was an increase in heart rate, perceived tension and pain and decrease in accuracy for all groups during the stressful tasks with symptomatic workers producing more typing errors than controls and workers without pain. These findings suggest an altered muscle recruitment pattern in the neck flexor and extensor muscles. Whether this is a consequence or source of the musculoskeletal disorder cannot be determined from this study. It is possible that workers currently without symptoms may be at risk of developing a musculoskeletal disorder.     

Results of a controlled,experimental, outcome study of nondrug treatments for the control of migraine headaches

Headache variables were examined for 136 subjects who participated for 36 weeks in one of four groups-No Treatment, Autogenic Phrases, Electromyographic (EMG) Biofeedback, and Thermal Biofeedback. All subjects kept daily records of headache activity and medication usage and participated in 22 laboratory sessions during which frontalis electromyographic and handtemperature measurements were taken; those in the three treatment groups practiced at home. There was a substantial reduction in headache variables in all groups. The No-Treatment Group differed significantly from the treatment groups combined, with the least reduction in headache variables. The Thermal Biofeedback Group vs. EMG Biofeedback and Autogenic Phrases Groups showed a suggestive trend toward improvement in the frequency and intensity of total headache.This work was supported by Grant MH26026 from the National Institute of Mental Health and by grants from the National Migraine Foundation and the P. W. Skogmo Foundation.     

Lack of Correlation Between Frontalis EMG and Either Neck EMG or Verbal Ratings of Tension

Eight normal subjects were trained with the aid of EMG feedback to successively increase and decrease the activity of the frontalis muscle on 5 consecutive days. Along with the activity of the frontalis, sternomastoid EMG was recorded from 4 subjects and EMG from both the semispinalis and splenius capitus was recorded from the other 4 subjects. Estimates of the degree of subjective tension or relaxation were obtained following Baseline, Increase Frontalis, and Decrease Frontalis periods on each treatment day. Frontalis EMG activity showed significant increases and decreases relative to baseline levels during appropriate periods. Sternomastoid EMG did not change significantly during either Increase Frontalis or Decrease Frontalis periods. Semispinalis/splenius EMG activity also did not change during Increase Frontalis periods, but increased significantly during Decrease Frontalis periods. Subjects’estimates of subjective tension increased above baseline during increases in frontalis EMG activity, but did not change significantly during decreases in frontalis EMG. These data support the findings of Alexander that changes in frontalis EMG neither generalize to other somatic muscles nor correlate with verbal reports of cognitive tension or relaxation.     

Chest muscle activity and panic anxiety: a preliminary investigation

This report represents a pilot investigation of the role of chest muscle electromyographic (EMG) activity in developing panic episodes. Chest EMG activity was obtained as part of a larger study examining ventilatory differences between panic sufferers and normal controls. Frontalis EMG, heart rate, and minute ventilation (breathing rate and tidal volume) were also obtained during the study. The ventilatory procedure involved exposing the subjects to three periods of carbon dioxide gas inhalations (1%, 3%, 5%; balance oxygen). Subjective measures of frightening cognitions and body sensations were obtained across the inhalation phases as well. The panic disorder subjects were divided, on the basis of subjective anxiety ratings obtained throughout the study, into high anxious (HA) and low anxious (LA) panic disorder groups. The HA panic disorder patients exhibited significantly higher chest EMG activity than the LA panic disorder patients and controls across all phases of the experiment. In addition, the chest EMG predicted, better than the other physiologic measures, the number of frightening cognitions and sensations reported by the subjects during the baseline and 5% CO2 inhalation phases. Overall, the results were supportive of the further study of chest wall EMG activity in the pathogenesis of panic attacks.     

Erector spinae SEMG activity during forward flexion and re-extension in ankylosing spondylitis patients

Objective: To compare erector spinae muscle (ESM) activity as measured by surface electromyography (SEMG) in lumbar flexion from the upright position in men with ankylosing spondylitis (AS) and healthy males, and to study associations between pain, lumbar mobility and ESM activity. Methods: Surface EMG was undertaken at the L1-2 and L4-5 levels in 11 men with AS taking part in a rehabilitation course at the Rheumatism Foundation Hospital, and in 10 pain-free male controls, while the subjects were bending forward. Results: During full flexion ESM SEMG activity was significantly greater in patients with AS than in the controls. Relaxation was evident during flexion in all of the controls but in only some patients with AS. Lumbar mobility correlated negatively with ESM activities. No relationship between pain and ESM activity was evident. Some AS patients reported pain while ESM activity was being measured. Conclusion: Decreased lumbar mobility rather than pain explains ESM activity during full flexion in patients with AS.     

Symptom-Specific Psychophysiological Responses in Chronic Pain Patients.

Symptom-specific psychophysiological responding was assessed in 20 chronic back pain patients, 20 patients suffering from temporomandibular pain and dysfunction, and 20 matched healthy controls. Surface EMG from the lower and upper back, the masseter, and the biceps muscles, and heart rate and skin conductance level were continuously recorded during adaptation, resting baseline, and stressful and neutral imagery phases. Univariate and multivariate analyses of variance were performed on raw data as well as data corrected for autocorrelation. The results showed significantly higher EMG reactivity which was lateralized to the left side at the patients' site of pain but not distal sites. This hyperreactivity was observed only during stressful imagery. The healthy controls displayed a significantly higher response in heart rate, but skin conductance level was not significantly different. The results are interpreted as indicative of idiosyncratic muscular response patterns to personally relevant situations at the site of pain in patients suffering from chronic muscular pain.     

Hysteresis in corticospinal excitability during gradual muscle contraction and relaxation in humans

Many studies have demonstrated that the firing behavior of single motor units varies in a nonlinear manner to the exerted torque during gradual muscle contraction and relaxation. However, it is unclear whether corticospinal excitability has such a hysteresis-like feature. In this study, we examined corticospinal excitability using transcranial magnetic stimulation (TMS) during gradual muscle contraction and relaxation for torque regulation in elbow flexor muscles. Eight healthy male subjects performed two different isometric elbow flexion tasks, namely, sinusoidal and tonic torque exertion tasks. In the sinusoidal task, the subjects sinusoidally increased and decreased the isometric elbow flexion torque (range of 0–15% of maximum voluntary contraction) at three different frequencies (0.33, 0.17, and 0.08 Hz). For each ascending (contraction: CON) and descending (relaxation: REL) period of the exerted torque, a single TMS was applied at 5 phases. In the tonic task, the elbow flexion torque was tonically exerted at 7 levels in a similar range as that in the sinusoidal task. EMG activities were recorded from the agonists, the biceps brachii (BB) and brachioradialis (BRD) muscles, and an antagonist, the triceps brachii (TB) muscle. The results demonstrated that the EMG activities of both the agonists and antagonist were larger in the CON period than the REL period, even when the exerted torque was the same. However, there were no significant differences in EMG activation profiles among the different frequencies of contraction. In BB and BRD, the motor-evoked potential (MEP) elicited by the TMS was also greater in the CON period than in the REL period. This CON-REL difference of MEP amplitudes was still observed when corrections were made for the increased EMG activities; that is, the MEP amplitudes to the identical EMG activities were greater in the CON period than in the REL period, and this phenomenon was more pronounced at higher frequencies. In addition, the degree to which sinusoidal MEPs exceeded tonic MEPs in the CON period and were smaller than tonic MEPs in the REL period became more pronounced at higher frequencies. On the other hand, there were significant correlations between the BB and BRD MEP amplitudes and the rate of change of elbow flexion/extension torque. These results indicate that corticospinal excitability during muscle contraction and relaxation has a neural hysteresis to the muscle activity, i.e., spinal motoneuronal activity, according to the rate of change of the exerted torque, i.e., muscle tension. This suggests that corticospinal excitability modulation depends not only on concurrent spinal motoneuronal activity and muscle tension but also on the time-series pattern of their changes during muscle contraction and relaxation.     

Physiological responses of type A and type B men during cognitive performance

Twenty male medical students classified as Type A or Type B solved a Concept Identification (CI) problem while measurements were taken on cardiovascular and somatic activity. The As produced significantly more overall electromyogram (EMG) activity and greater vasomotor activity than the Bs at baseline and during the task. Both Type As and Bs showed significantly higher levels of Heart Rate (HR), systolic and diastolic blood pressures, skin conductance, frontal EMG, and lower levels of vasomotor activity during work on the problem than during pre- and post-problem baselines. Type As showed significant negative correlations between total errors during CI and level of vasomotor activity, and between postsolution response latency and skin conductance. Type Bs showed a strong positive association between presolution response time and heart rate that did not hold for the As. The As appear to have shown sympathetic activation associated with quality of problem-solving performance, while the B's showed a relationship that suggested an impaired efficiency of performance associated with cardiac activation.     

Headache versus nonheadache state: a study of electrophysiological and affective changes during muscle contraction headaches

Seventeen carefully screened muscle contraction headache sufferers were tested in both the headache and the nonheadache state. At baseline, forehead and trapezius EMG were higher, whereas finger temperature and finger blood volume were lower in the headache than the nonheadache state. At a borderline level, physiological reactivity was greater during the headache than the nonheadache state in response to a reaction-time stressor. During the headache state, subjects also reported themselves to be more anxious, depressed, and angry than they were in the nonheadache state and said they felt themselves to be more hassled by external stressors and less able to cope with, prevent, and control their headaches. The findings are consistent with the notion that shoulder/neck tension and emotional arousal contribute to tension headaches. Evidence is less clear for the contribution of vasomotor factors and general physiological reactivity.     

The Effects of Psychological and Environmental Stressors on Peristaltic Esophageal Contractions in Healthy Volunteers

The relationship between various stressful stimulus conditions, measures of anxiety, and altered esophageal motility was investigated in mo experiments employing normal adult volunteers. In Experiment 1, subjects were administered separately I00dB continuous white noise and a cold pressor task. In Experiment 2. subjects were administered in a counterbalanced order intermittent and unpredictable bursts of 100dB white noise and a cognitive task consisting of solvable and unsolvable discrimination problems. Results of both experiments showed that the amplitudes of peristaltic esophageal contractions and levels of state anxiety self-reports were significantly higher during periods of stress than during preceding baseline periods. Furthermore, in Experiment 2, esophageal contraction velocities and anxiety-related behaviors were significantly greater during stress periods than during baselines. Contrary' to previous studies, few abnormal tertiary esophageal contractions were elicited by stress. The present results identify increased amplitude of the peristaltic contractions as the primary esophageal response to stress. Technological and methodological differences between this study and previous Investigations of affective disturbance among patients with chronic esophageal chest pain also are examined.     

Acute chest pain without obvious organic cause before the age of 40. Respiratory and circulatory response to mental stress

Reactivity to mental stress and relaxation was studied in 63 consecutive patients below the age of 40 attending the emergency care unit because of chest pain without obvious organic cause. The results were compared with a control group (n = 32). Of the patients, 41% reported chest pain or oppression in the chest during mental stress compared to 10% of the control subjects (p less than 0.01). During relaxation the subjects in the female patient group reported significantly less ability to relax and had significantly higher respiration rate as compared to the female control group. There were no significant differences between the groups regarding heart rate, blood pressure or end-tidal PCO2 and there was no evidence of hyperventilation, neither during relaxation nor during mental stress. In combination with our earlier findings of high scores for "type A behaviour", "neuroticism", "vital exhaustion" and "stressful life events" these findings indicate that psychosomatic mechanisms may be of great importance for the development of chest pain in this group of patients.     

Muscle tension in generalized anxiety disorder: Elevated muscle tonus or agitated movement?

The purpose of this study was to investigate the amplitude characteristics of frontalis and gastrocnemius electro-myographic (EMG) activity in clinically anxious and nonanxious populations. Eighteen women with generalized anxiety disorder (GAD) and 19 nonanxious women were compared during baseline, laboratory stressor, and recovery conditions. EMG mean levels were greater for the GAD group, but there were no group differences in EMG skewness. During the stressor the GAD group had a significant reduction in frontalis EMG variability. Gastrocnemius muscle activity for both groups during the stressor condition increased in mean levels and variability while decreasing in skewness. These results indicate that clinically anxious individuals have elevated muscular tonus and have reduced variability in frontalis activity during stressful tasks. Also, the gastrocnemius muscle exhibited a stressor reactivity, whereas the frontalis did not. This study presents an approach to EMG analysis that could be useful in distinguishing unique features of anxiety as well as other emotional disorders.     

Association of Aerobic Fitness with Pulse Rate and Subjective Responses to Psychological Stress

Ten high fit and 10 low fit subjects first sat quietly during a baseline period and then participated in a mildly stressful task (recall of digits backwards). Pulse rates and levels of subjective arousal were assessed during the baseline period and during the task performance period. Initial analyses indicated that task performance resulted in general increases in pulse rates, subjective cognitive arousal, and subjective somatic arousal. More importantly, it was found that high fit subjects evinced a smaller pulse rate increase in response to stress than did low fit subjects, but the high and low fit subjects did not differ in their subjective responses to stress. These results are consistent with a growing body of research which indicates that a high level of aerobic fitness is associated with reduced physiological reactivity to psychological stress.     

Psychophysiological responses to stress in patients with myofascial pain-dysfunction syndrome

The hypothesis was tested that patients diagnosed with myofascial pain-dysfunction (MPD) syndrome display a Stereotypic response to stress via increased activity in the facial muscles. Twenty MPD patients and 20 matched control subjects were seated and exposed to affectively neutral, then stressful, then affectively neutral film clips. During film viewing, heart rates and skin-conductance levels were recorded along with bilateral EMG activity from the frontalis, temporalis, and masseter muscles and unilateral EMG activity from the forearm extensor. While both groups showed facial EMG responses to the stressor, MPD patients showed lower heart-rate and skin-conductance responses to experimental stress than did normals and a differentially higher frontalis EMG response. MPD patients also showed higher resting EMG levels than did normals at four of six facial muscle sites.     

Personality traits and stress sensitivity in migraine patients

A review of the literature on migraine and personality yielded strong evidence for secondary neuroticism and increased sensitivity to stress in patients with migraine. This study focused on the identification of specific stressful situations and coping strategies in such patients. We conducted a psychodiagnostic study of 30 migraine patients in accordance with the criteria of the Headache Classification Committee of the International Headache Society and 30 healthy control subjects matched for age, sex, and social status. All participants completed the Minnesota Multiphasic Personality Inventory (MMPI) and special questionnaires on stressful situations and coping strategies. The migraine patients had higher neuroticism and introversion scores on the MMPI than the healthy subjects. There was a positive correlation between the neuroticism score and headache duration (number of hours per week). The patients used coping strategies characterized by the development of physical symptoms, social isolation, and preoccupation with stress. They rated themselves as less calm, less capable of relaxing, and more irritable than did the healthy controls subjects, and they responded more often with internal tension, especially in work and other achievement situations. Questionnaires that measure constructs dealing with stress yield information that is more relevant for the treatment of migraines than do global personality tests.