Fibromyalgia comorbidity in primary headaches

Fibromyalgia syndrome (FMS) is a chronic pain condition of unknown aetiology characterized by diffuse pain and tenderness at tender points. The aim of the study was to assess the prevalence and clinical features of FMS in the different forms of primary headaches, in a tertiary headache centre. Primary headache patients ( n  = 217) were selected and submitted to the Total Tenderness Score, anxiety and depression scales, Migraine Disability Assessment, allodynia questionnaire, Short Form 36 Health Survey and the Medical Outcomes Study-Sleep Scale. In patients with FMS, the Multidimensional Assessment of Fatigue, the Pain Visual Analog Scale, the Manual Tender Point Survey and the Fibromyalgia Impact Questionnaire were employed. FMS was present in 36.4% of patients and prevailed significantly in tension-type headache and in patients with higher headache frequency. Headache frequency, pericranial muscle tenderness, anxiety and sleep inadequacy were especially associated with FMS comorbidity. In the FMS patients, fatigue and pain at tender points were significantly correlated with headache frequency. FMS seems increasingly prevalent with increased headache frequency, for the facilitation of central sensitization phenomena favoured by anxiety and sleep disturbances.     

Pressure-controlled palpation: a new technique which increases the reliability of manual palpation

The objective of the present study was to investigate whether the reliability of tenderness evaluation can be increased by using a new technique called "pressure-controlled palpation" (pcp). The technique has been made possible by a newly invented piece of equipment called a palpometer, with which a pressure-sensitive plastic film attached to the index finger records the pressure exerted. In 15 patients with chronic tension-type headache and in 15 healthy volunteers, 2 investigators studied myofascial tenderness using conventional palpation and pressure-controlled palpation. Tenderness was scored on a 4-point scale in each of the examined pericranial regions. The sum of tenderness scores recorded by two observers using conventional palpation differed significantly ( p = 0.0003), while results did not differ between observers using pressure-controlled palpation ( p = 0.89). During palpation with seven different pressure intensities a positive and linear relation between pressure and pain intensity was found ( p = 0.00006). Pain intensity reported by the subjects correlated highly with tenderness scored by the observer ( r_s = 0.95, p < 0.0001). These results demonstrate for the first time that tenderness scores can be compared between observers if palpation pressure is controlled. Pressure-controlled palpation represents a major improvement on current palpation techniques and should be standard in future research on myofascial pain disorders.     

Clinical Characterization of Patients with Chronic Tension Headache

SYNOPSIS
One hundred and forty-eight patients with tension headaches at least 10 days per month were studied prospectively with a standardized interview, neurological examination and evaluation of muscle tenderness and jaw movements. Patients with migraine attacks oftener than once per month were excluded. Ninety-three had daily headache. Median age at onset was 23 yrs. (quartiles 15–23 yrs.). Half of the patients had headache predominating in one part of the head. In the other half, headache was diffuse or with changing pattern. Fifty-eight reported migraine attacks 1–12 times per year; twenty-seven of these did not remember onset, 15 initially had migraine later developing into chronic headache, and 16 started with tension headache and developed migraine attacks later in life. Photophobia was reported as frequently associated with tension headache (migraine attacks not included) in 13 percent, infrequently in 38 percent and absent in 49 percent. Corresponding figures for phonophobia were 7, 35 and 57 percent. Characteristics of chronic tension headache were similar in patients with and without migraine attacks. The components included in the usual indices of temporo-mandibular joint dysfunction showed little mutual correlation. Pericranial tenderness scores were elevated compared to previously studied controls. Tenderness in paravertebral muscles was significantly correlated to pericranial tenderness, and patients indicating influence by environmental factors had the highest pericranial tenderness scores. The findings are suggestive of a generalized muscular reaction to environmental stress in the majority of patients.     

Scalp Tenderness and Sensitivity to Pain in Migraine and Tension Headache

SYNOPSIS
Pressure-pain threshold was assessed in the forehead, temples, occiput and neck of 102 patients with migraine or tension headache, and in 35 nonheadache control subjects of similar age and sex distribution. Pain sensitivity to the application of a weighted blade to the fingers was also assessed. Tenderness was greater in patients than in controls, particularly at the site of migraine or tension headache, and to a lesser extent in other areas of the scalp. Scalp tenderness persisted for several days after headache had subsided. The threshold for pain in the fingers was greater during headache than during the headache-free interval but did not differ from pain threshold in control subjects. Pain in the fingers increased more rapidly in patients with episodically-recurring tension headaches than in other patient categories or control subjects. These findings demonstrate that scalp tenderness is not due to a general increase in sensitivity to pain during migraine. In contrast, diffuse disruption of central pain modulating systems may be involved in the pathophysiology of episodically-recurring tension headaches.     

Increased prevalence of tension-type headache over a 12-year period is related to increased pain sensitivity. A population study

We recently reported an increase in prevalence and frequency of tension-type headache (TTH) over a 12-year period in the young Danish population. The aim of the present study was to analyse whether this increase was related to increased pain sensitivity. The study was a cross-sectional replicate of a large Danish population study. It compared 113 subjects aged 25-36 years in 2001, with 221 comparable subjects in 1989. Tenderness was considerably higher in 2001 than in 1989. When stratified according to presence of headache, the increase in tenderness was clinically and statistically significant only in women with frequent TTH. The pressure pain threshold was significantly lower in 2001 compared with 1989 in women with frequent TTH. The increase in tenderness in the population may predict an even higher prevalence of TTH in future. The changes support the hypothesis of central sensitization in TTH.     

Heat pain thresholds and cerebral event-related potentials following painful CO2 laser stimulation in chronic tension-type headache

Current opinion concerning the pathophysiology of tension-type headache (TTH) and its related pericranial muscle tenderness proposes a primary role of central sensitization at the level of dorsalhorn/trigeminal nucleus as well as the supraspinal level. Investigation of these phenomena can be conducted using laser-evoked potentials (LEPs), which are objective and quantitative neurophysiological tools for the assessment of pain perception. In the present study we examined features of LEPs, as well as cutaneous heat-pain thresholds to laser stimulation, in relation to the tenderness of pericranial muscles in chronic TTH resulting from pericranial muscle disorder, during a pain-free phase. Twelve patients with TTH and 11 healthy controls were examined using the Total Tenderness Scoring (TTS) system. The stimulus was a laser pulse generated by a CO(2) laser. The dorsum of the hand and the cutaneous zones corresponding to pericranial muscles were stimulated. Subjective perception of stimulus intensity was assessed by a visual analogue scale. Two responses, the earlier named N2a and the last named P2, were considered; the absolute latency was measured at the highest peak of each response. The N2a-P2 components' peak-to-peak amplitude was detected. The heat pain threshold was similar in TTH patients and controls at the level of both the hand and pericranial skin. The TTS scores at almost all pericranial sites were higher in TTH patients than in normal controls. The amplitude of the N2a-P2 complex elicited by stimulation of the pericranial zone was greater in TTH patients than in controls; the amplitude increase was significantly associated with the TTS score. Our findings suggest that pericranial tenderness may be a primary phenomenon that precedes headache, and is mediated by a greater pain-specific hypervigilance at the cortical level.     

Dynamic assessment of abnormalities in central pain transmission and modulation in tension-type headache sufferers

OBJECTIVE: To examine and compare central pain processing and modulation in young tension-type headache sufferers with that of matched healthy controls using an induced headache "challenge" paradigm. BACKGROUND: Recent research has suggested that abnormalities in central pain processing and descending pain modulation may contribute to chronic tension-type headache. These abnormalities, if they contribute to headache pathogenesis, should be present in young adult tension-type headache sufferers. Recent research using static measures of physiological variables, such as muscle tenderness and exteroceptive suppression, has identified chronic muscle tenderness as a characteristic of young tension-type headache sufferers, but other central nervous system functional abnormalities may require a dynamic "challenge" to be observed. METHODS: Twenty-four young women meeting the International Headache Society diagnostic criteria for tension-type headache (headache-prone) and a matched group of 24 healthy women who reported fewer than 10 problem headaches per year (control) participated in a double-blind, placebo-controlled, crossover study. Subjects completed jaw clenching and a placebo condition on different days in counterbalanced order. Pericranial muscle tenderness, pressure-pain thresholds on the temporalis, and exteroceptive suppression periods were assessed before and after each procedure. Head pain was recorded for 12 to16 hours following each condition. RESULTS: Headache-prone subjects were more likely than controls to experience headaches after both the jaw clenching and placebo procedures, but neither group was significantly more likely to experience headaches following jaw clenching than placebo. In pretreatment measurements, headache-prone subjects exhibited greater muscle tenderness than controls, but pressure-pain detection thresholds and exteroceptive suppression periods did not differ in the two groups. Control subjects showed increases in muscle tenderness and exteroceptive suppression periods following both the clenching and placebo procedures, whereas headache-prone subjects exhibited no significant changes in any of the physiological measures following either experimental manipulation. CONCLUSIONS: These results confirm previous findings indicating abnormally high pericranial muscle tenderness in young tension headache sufferers even in the headache-free state. In addition, the results suggest that the development of headaches following noxious stimulation is more strongly related to headache proneness and associated abnormalities in central pain transmission or modulation (indexed by pericranial muscle tenderness and exteroceptive suppression responses) than muscle strain induced by jaw clenching.     

Muscular disorders in tension-type headache

In order to evaluate the diagnostic criteria for muscular disorders in tension-type headache, pericranial muscle tenderness and pressure pain thresholds were studied in a random sample population of 735 adults aged 25–64. In addition, quantitative EMGs were recorded in 547 of these subjects. The correlation between the three diagnostic tests was assessed and the discriminality and cut-off points were analysed using Receiver Operating Characteristics analysis. Local tenderness from the temporal muscles was closely related to the total tenderness scores from 14 pairs of muscles. In chronic tension-type headache, tenderness was positively related to EMG and inversely related to pain thresholds. In the episodic form the total tenderness score was inversely related to pain thresholds, whereas no significant relation to EMG was noted. The Receiver Operating Characteristics curves indicated that tenderness recorded by manual palpation was the most specific and sensitive test, whereas EMG and pain thresholds were of limited diagnostic value. Eighty-seven percent of subjects with the chronic, and 66% of subjects with the episodic form were found to have a "muscular disorder" defined as increased tenderness recorded by either manual palpation or pressure algometry and/or increased EMG levels. However, muscle tenderness increased significantly during pain, so the headache state should be considered in future studies. Suggestions for revision of the present diagnostic criteria for muscular disorders are given.     

Head pain referral during examination of the neck in migraine and tension-type headache

Objective.— To investigate if and to what extent typical head pain can be reproduced in tension‐type headache (TTH), migraine without aura sufferers, and controls when sustained pressure was applied to the lateral posterior arch of C1 and the articular pillar of C2, stressing the atlantooccipital and C2‐3 segments respectively. Background.— Occipital and neck symptoms often accompany primary headache, suggesting involvement of cervical afferents in central pain processing mechanisms in these disorders. Referral of head pain from upper cervical structures is made possible by convergence of cervical and trigeminal nociceptive afferent information in the trigemino‐cervical nucleus. Upper cervical segmental and C2‐3 zygapophysial joint dysfunction is recognized as a potential source of noxious afferent information and is present in primary headache sufferers. Furthermore, referral of head pain has been demonstrated from symptomatic upper cervical segments and the C2‐3 zygapophysial joints, suggesting that head pain referral may be a characteristic of cervical afferent involvement in headache. Methods.— Thirty‐four headache sufferers and 14 controls were examined interictally. Headache patients were diagnosed according the criteria of the International Headache Society and comprised 20 migraine without aura (females n = 18; males n = 2; average age 35.3 years) and 14 TTH sufferers (females n = 11; males n = 3; average age 30.7 years). Two techniques were used specifically to stress the atlantooccipital segments (Technique 1 – C1) and C2‐3 zygapophysial joints (Technique 2 – C2). Two techniques were also applied to the arm – the common extensor origin and the mid belly of the biceps brachii. Participants reported reproduction of head pain with “yes” or “no” and rated the intensity of head pain and local pressure of application on a scale of 0 ‐10, where 0 = no pain and 10 = intolerable pain. Results.— None of the subjects reported head pain during application of techniques on the arm. Head pain referral during the cervical examination was reported by 8 of 14 (57%) control participants, all TTH patients and all but 1 migraineur (P < .002). In each case, participants reported that the referred head pain was similar to the pain they usually experienced during TTH or migraine. The frequency of head pain referral was identical for Techniques 1 and 2. The intensity of referral did not differ between Technique 1 and Technique 2 or between groups. Tenderness ratings to thumb pressure were comparable between the Techniques 1 and 2 when pressure was applied to C1 and C2 respectively and across groups. Similarly, there were no significant differences for tenderness ratings to thumb pressure between Technique 1 and Technique 2 on the arm or between groups. While tenderness ratings to thumb pressure for Technique 2 were similar for both referral (n = 41) and non‐referral (n = 7) groups, tenderness ratings for Technique 1 in the referral group were significantly greater when compared with the non‐referral group (P = .01). Conclusions.— Our data support the continuum concept of headache, one in which noxious cervical afferent information may well be significantly underestimated. The high incidence of reproduction of headache supports the evaluation of musculoskeletal features in patients presenting with migrainous and TTH symptoms. This, in turn, may have important implications for understanding the pathophysiology of headache and developing alternative treatment options.     

The Comparison of Patients Suffering from Temporo-mandibular Disorders and a General Headache Population

SYNOPSIS
The purpose of this study was to examine the possible association of signs and symptoms of temporomandibular disorders relative to headache. Fifty-six sequential patients referred to the Headache Institute of Minnesota for evaluation and treatment of migraine and tension headaches were examined for signs and symptoms of temporomandibular disorders. The results of the examination of headache patients were compared to patients suffering from myofascial pain dysfunction and/or TMJ internal derangements from the TMJ and Craniofacial Pain Clinic at the University of Minnesota. Finally the migraine and tension headache patients were compared to each other and an asymptomatic population.
Results indicate that patients with temporomandibular disorders exhibit significantly more jaw dysfunction and pericranial muscle tenderness than migraine and tension headache patients. ^Migraine and tension headache patients were found to have similar amounts of pericranial muscle tenderness. Migraine and tension headache patients exhibited significantly more pericranial and neck muscle tenderness than a general population.