Muscle tenderness in tension headache treated with acupuncture or physiotherapy
Jane Carlsson, Astrid Fahlcrantz, Lars-Erik Augustinsson
CEPHALALGIA Carlsson J, Fahlcrantz A, Augustinsson L-E. Muscle tenderness in tension headache treated with acupuncture or physiotherapy. Cephalalgia 1990;10:131-41. Oslo. ISSN 0333-1024 Sixty-two female patients with chronic tension headache were randomized into two treatment groups-acupuncture and physiotherapy. The intensity of headache, muscle tenderness and neck mobility was assessed before and after treatment. Thirty healthy women were used for comparison. Before treatment it was found that muscle tenderness was increased and neck rotation was reduced in the patient group compared with controls. There was a significant correlation between the intensity of headache and muscle tenderness. After treatment, the intensity of headache and muscle tenderness were reduced in both treatment groups. The headache was more improved in the physiotherapy group, and there was a marked reduction in the intake of analgesics. The tenderness was reduced in all muscles tested in the physiotherapy group but only in some of the muscles after acupuncture. The limitation of neck rotation was not influenced by either treatment. • Acupuncture, muscle tenderness, neck mobility, physiotherapy, tension headache Jane Carlsson, Department of Neurology; Astrid Fahlcrantz, Department of Physiotherapy; Lars-Erik Augustinsson, Department of Neurosurgery; all at the University of Göteborg, Sahlgrenska sjukhuset, S-413 45 Göteborg, Sweden; Accepted 17 April 1990 Tension headache has a multifactorial aetiology including both somatic and psychological factors (1). Monotonous work and unsuitable working positions are known causative factors. The headache is usually made worse by anxiety, stress and noise. Most patients are conscious of the fact that they are never really relaxed. According to Lance (2), approximately one-third have symptoms of depression. Muscle contraction can occur as a secondary phenomenon, e.g. in response to pain originating in other head or neck structures (3). Many patients tend to increase their intake of analgesics, which, paradoxically, can increase the pain (4). The pathogenetic mechanisms underlying tension headache are not known. Sustained contraction of the muscles of the neck, head and face is considered a probable cause of pain (5). Frequent involvement of the neck musculature, expressed as limitation of neck movements, is also reported (3). Additional vasoconstriction in the contracted muscles is supposed to cause ischaemia with worsening of the pain (1). Some investigators, however, have not been able to show any significant difference in EMG recordings from the forehead and neck muscles in patients with tension headache and those of normal controls (6). Tenderness of pericranial muscles is present in most headache patients (7). Langemark and Olesen (8) have found a significant correlation between the intensity of tension headache and a total tenderness score. The term "tension headache" used in this article is synonymous with muscle contraction headache as defined by the Ad Hoc Committee of the US National Institute of Health in 1962 (9). The new operational criteria of the International Headache Society in 1988 (10) introduced the term "tension-type headache", which also includes patients with normal levels of muscle tenderness and in whom EMG of pericranial muscles shows normal levels of activity. Medical treatment with analgesics, anti-depressants and relaxants has been and is still frequently used. Acetylsalicylic acid is probably the most widely used drug but, to the best of our knowledge, its efficacy in tension headache has not been evaluated. A variety of non-pharmacological treatments
have been tried, such as behavioural therapy, psychotherapy, hypnosis and feedback techniques (11). General forms of physiotherapy have been tried but more specific programmes have also been presented (12, 13). It has also been suggested that acupuncture may be useful (14). The lack of consistency reported by different authors concerning the relationship between contraction of pericranial muscles, muscle tenderness and tension headache as well as the diversity of the mostly non-evaluated therapies initiated the present study, the aims of which were: 1. to compare the frequency and severity of tenderness in pericranial muscles and the range of neck mobility in patients with tension headache with the same variables in a healthy control group, and 2. to study whether the headache, the tenderness of the pericranial muscles and the limitation of neck movements can be reduced with physiotherapy and acupuncture and if so which treatment is more effective. Patients
Sixty-two consecutive female patients with chronic tension headache were invited to participate in the study. All of them had been examined at the outpatient clinics of the Department of Neurology and Neurosurgery. Sahlgrenska Hospital, Göteborg from March 1984 to November 1987. Only females between 18 and 60 years of age (mean age 34 years) were accepted for the study. Exclusion criteria were: malignant or other serious diseases, headache which had started in close temporal relation to an organic disorder and difficulty in understanding and speaking Swedish. Patients with generalized myalgia and headache as part of a fibromyalgic syndrome were also excluded. Each patient underwent a full neurological examination and at the same time a comprehensive history was taken. There were no neurological or muscular diseases causing disseminated or focal signs in any of the patients. The diagnosis of tension headache was based on the criteria established for muscle contraction headache by the NIH in 1962 (9). This type of headache appears almost daily as a constant tight pressing or bandlike sensation in the occipital, temporal and/or frontal areas. The pain is bilateral but not necessarily symmetrical. Twenty-three patients had a mixed type of headache-a combination of tension headache and migraine with a clear predominance of the tension headache. The migraine component was of a mild form, from three attacks a year up to one attack a month. The low frequency of migraine attacks made a post-treatment evaluation impossible in this communication. Thirty-one patients complained of dizzinesss. The duration of the headache varied between 6 months and 33 years (median duration 7 years). Four patients were receiving a disability pension, five patients were on sick leave and two were unemployed on entering the study. Many of the patients had taken analgesics, most often acetylsalicylic acid (ASA) and paracetamol. When the study started, 16 patients were taking a few tablets a week, 27 patients moderate daily doses and six patients were taking more than 5g (10 tablets) of ASA daily. Ten patients took no analgesics at all. Patients with migraine took various anti-migraine compounds. Five patients took 5-15 mg of diazepam daily on an irregular basis and two patients were on tricyclic antidepressants. The patients were
told not to take any analgesics on the day when the tests were performed. All but two of the patients had previously tried some therapy for their headache. Twenty-eight had been taking analgesics exclusively and 20 analgesics and some other therapy such as relaxation programmes, transcutaneous electrical nerve stimulation (TENS), zone therapy, ultrasound or acupuncture. Nine patients had tried more than three different therapies. The previous therapies had no or only temporary effect. The type and severity of the patients' headaches were evaluated in 30 patients before the treatment period started. The headache intensity was assessed on a visual analogue scale on two occasions with an interval of 5-7 weeks. It appeared that the headache intensity did not differ markedly between the two registrations. If an error of ±10 mm on the 100 mm scale is accepted, 24 patients were unchanged, 3 were improved and 3 had become worse. The patients were randomized into two groups. Thirty-one patients had acupuncture and 31 physiotherapy. Two patients did not come to the tests before treatment and one patient did not fulfil the inclusion criteria. All three had been randomized to acupuncture. A further five patients in the acupuncture group and two patients in the physiotherapy group dropped out. Of these, one moved abroad, one was pregnant and therefore not suitable for acupuncture, one could not cope because of abuse of alcohol and four interrupted the study due to lack of time. The drop-outs did not differ from the other patients with respect to the variables studied. This means that 23 patients in the acupuncture group and 29 patients in the physiotherapy group completed the study. The patients' informed consent to participation in the research project was obtained. A control group consisting of 30 healthy women aged from 19 to 56 years (mean age 36 years) selected from a non-clinical population was used for comparison. Methods
All patient tests were performed by one of the authors (AF), who did not take part in the treatment programme. The tests took place 3 to 8 weeks before the start of the treatment and were repeated 4 to 9 weeks after the termination of treatment. Intensity of the headache The patients were asked to rate the intensity of the headache before and after treatment. A five-point scale was used, with the following levels of pain intensity: 1 none or negligible, 2 mild, 3 moderate, 4 severe and 5 incapacitating headache. Muscle tenderness The degree of tenderness was evaluated by palpation of six pericranial muscles on each side of the head. The muscles were selected because they correspond to the location of headache, are superficial and are easy to find. The tenderness was assessed according to a four-point scale which corresponds well with the scale presented by Langemark and Olesen in 1987 (8). The following levels of pain intensity on palpation were used: 0 = no report of pain and no visible reactions, 1 = report of tenderness but no visible reaction, 2 = report of painful tenderness and visible reaction, 3 = report of severe pain and marked visible reaction, "jump sign" (7). The muscle sites chosen for palpation, depicted in Fig. 1, were as follows: 1. The origin of the superficial part of the masseter muscles at the anterior two-thirds of the lower border of the zygomatic arch. 2. The origin of the orbicularis oculi muscles at the medial corner of the eye. 3. The upper anterior part of the origin of the temporalis muscles. 4. The origin of the corrugator muscles at the medial end of the superciliary notch. 5. The insertion of the sternocleidomastoid muscles at the mastoid process. 6. The origin of the trapezius muscles at the external occipital protuberance. The subjects were placed in a relaxed recumbent position. The second and third fingers were used for palpation and the subject's
head was supported with the other hand. The palpation was done with small circulating, mildly pressing movements. The muscles were examined in the order given above. The mean values for each pair of the 12 palpated muscles were calculated. A total tenderness score (8) for each patient was obtained by adding the scores from all palpated sites, the maximum score being 12 x 3 = 36. Cervical spine mobility The neck mobility was measured with an inclinometer ("Myrin") (The Myrin inclinometer is produced by LIC, Svetsarvägen 4, 172 83 Solna, Sweden) (15). All movements, including flexion, extension, side flexion and rotation, were measured with the subject seated. She was instructed to sit straight up, right back into the chair, and to avoid opening her mouth during extension. During flexion/extension movements, a Velcro band was firmly fixed around the head above the eyebrows. The inclinometer was then placed on the band just above the ear, the zero point being lined up with the tragus. During side flexion, the inclinometer was placed, without moving the band, at the front of the head with the zero point lined up with the nose. During rotation, the inclinometer was placed on top of the head with the zero point lined up with the bridge of the nose. For each movement, the subject was instructed to move her head actively as far as she could. Care was taken to make sure that a pure movement of the head took place and movements of the shoulders or the back were minimized. Each movement was repeated twice and the best of the two readings recorded. In the control group, examination of the tenderness of pericranial muscles and the neck mobility was performed by two independently operating investigators in an attempt to assess the reliability of the methods. The two investigators had previously coordinated the techniques. Of 360 palpated sites, the two investigators reported equal values in 306 (85%) and of 180 measurements of neck mobility 163 recordings (91%) were within 15°. Both methods thus showed a high degree of reproducibility. In the patient groups, both tests were performed by one investigator. Statistical methods For comparison before and after treatment between variables measured within a separate treatment group, a linear non-parametric permutation test for paired observations was used. For comparison between the two treatment groups and between the treatment groups and controls, Fischer's non-parametric permutation test was used. For correlations between the different variables measured, Pitman's non-paramagnetic permutation test was used. Pearson product-moment correlation coefficient was used to describe the level of correlation between two variables (16). Treatment
Physiotherapy The therapy was given by a physiotherapist (J. C., one of the authors) who did not take part in the test programme. The treatment programme was specific for each patient. The goal was to teach the patient to handle any situation with as little physical tension as possible. The programme was divided into 10-12 sessions with an overlapping between different sessions. How much and what kind of information given was varied according to the patient's receptibility and motivation. The treatment extended over 2-3 months, with 1-2 sessions per week, each with 30-45 min of individual instruction. Session 1. History-taking including location, frequency, duration and quality of the headache. Possible factors leading to the headache, such as psychosocial stress, unsuitable working positions, monotonous work, craniomandibular disorders, etc., were discussed. The patient was instructed to avoid such causative factors, at least temporarily, in order to break the vicious circle of muscle spasm leading to pain, which in itself may lead to more muscle spasm.
Session 2. Inspection of the patient. This included observation of the patient's facial expression (whether she ground her teeth, wrinkled her forehead and/or narrowed her eyes) and standing position, sitting position and movement, especially the positioning of the head and shoulders. The mobility of the neck and shoulder was examined with the intention of finding tense and shortened muscles. This was the basis for the applied corrections of the patient's position during different activities. Session 3. The patient was told that she could obtain pain relief without analgesics. Massage, cryotherapy and TENS were used and managed by the patient herself. The patient was instructed to use these techniques daily at home in an individually adapted combination and at the same time reduce and eventually withdraw all intake of analgesics. Sessions 4 and 5. Relaxation of the whole body was performed according to a technique presented by Jacobsen (13), including two 10 min sessions of daily training at home. The intention was to make the patient aware of the difference between tense and relaxed muscles by practising contraction and relaxation of different muscles. The patient was instructed to start the training in a comfortable recumbent position in a peaceful environment. Eventually the difficulties in relaxing were increased by performing the training in the sitting position and in a less peaceful environment. Sessions 6 and 7. The contracted and tender muscles were dealt with specially. The muscle was contracted heavily for about 10 sec relaxed for 10 sec, then passively stretched for 20 sec. To help the patient to notice any warning sensation of tension, a piece of tape was placed on the skin over the contracted muscle(s). When the muscle started to contract, the patient felt the movement of the tape and could voluntarily stop the contraction and relax the muscle. Sessions 8 and 9. A final important step was to practise relaxation in everyday life. The patient must be aware of the way she stands, sits, walks and how she lies when sleeping. She must adopt a new and more economic pattern of use of the musculature and check that all muscles which are not essential for the task of the moment are in a state of relaxation. This applies to working situations such as writing, typing or speaking on the telephone as well as leisure activities such as reading, watching TV and sports. Session 10. When the patient had learned how to prevent the headache coming and to eliminate or reduce the headache once it had started, it was time to build up the patient's physical condition, including muscle strength, coordination, litheness and fitness. The training had to be planned according to an individually adapted programme which could be managed by the patient herself. Acupuncture Acupuncture was performed by two physicians using the same technique. One was one of the authors (L-E. A.), who did not take part in the test programme. The acupuncturist asked the patient about the type and site of the headache and examined the patient with respect to tender points in the pericranial musclature. He also explained the supposed physiological background to the effect of acupuncture in easily understandable terms. Standard 1.5 inch stainless steel electrodes were used. The needles were inserted perpendicularly to a depth where the s.c. Te Chi phenomenon occurs. In all patients, local points and one distal point were treated. The points are classical Chinese acupuncture points (17). The local points are the gall bladder (GB) meridian point numbers 20 and 21. Anatomically, GB20 corresponds to the major occipital nerve where it runs just medial to the mastoid process and GB21 to the middle of the upper border of the trapezius muscle. The distal points include the first dorsal interosseus muscle of the hands (LI 4). This point is called Hegu and is commonly used in traditional Chinese acupuncture for headache. Altogether six points were needled on each occasion. In patients
with a probable migrainous component in their tension headache, the following additional points were used: GB14 above the eyebrow, the extra points Tai Yang in the temporal region and Yin Tang between the eyebrows. At the first treatment session, the needles were inserted and twiddled by hand. From the second treatment on, electrical stimulation via the needles was used. The electrical parameters were frequency 1-2 Hz, pulse width 0.5 msec and an intensity high enough to cause comfortable contractions in the muscle-usually in the range of 4-7 volts. The length of each treatment session was at least 20 min. A standard trial period of 2-4 weeks was used. During this period, 4-5 single treatments were performed. If the patients hereafter reported clear pain relief, a further 4-5 treatments were given. The patients were asked to reduce their intake of analgesics as much as they considered possible. In a few patients, a slight vasovagal reaction was seen at the first treatment. Otherwise, no complications were noted. Results
Before treatment the values for muscle tenderness, intensity of headache and neck mobility were evenly distributed between the physiotherapy group and the acupuncture group. In the statistical analysis, the material was therefore considered homogeneous. Headache The location of headache before treatment is depicted in Fig. 2. After treatment, the headache was significantly reduced in both patient groups (Table 1). The headache intensity had become significantly lower in the physiotherapy group compared with the acupuncture group (p < 0.05). Patients who reported reduced intensity of their headache did not differ from those who did not with respect to the pretreatment levels of headache intensity, muscle tenderness or neck mobility.
Muscle tenderness Before treatment, the tenderness of the palpated muscles was significantly higher in the patient group compared with the controls (Table 2). There were no tender points above grade 2 among the controls. All patients had at least five tender points and there was a bilateral distribution of the tenderness in all patients. The tenderness was most pronounced on the right side of the head in the temporal, orbicularis oculi, sternocleidomastoid (p < 0.05) and corrugator (p < 0.01) muscles, while there was no difference between right and left side for the masseter and trapezius muscles. The average score for the controls was 2.4 and for the patients 21.3, representing 6.7% and 59.2% when calculated as a percentage of the maximal total score. A significant correlation was found between the intensity of headache and the tenderness of the temporal, masseter (p < 0.05) and trapezius muscles (p < 0.01). The average tenderness of all palpated
Table 1. Intensity of headache and muscle tenderness before and after treatment with physiotherapy and acupuncture. Physiotherapy Acupuncture Before After Before After treatment treatment Difference treatment treatment Difference Mean SD Mean SD Mean SD p Mean SD Mean SD Mean SD p Intensity of headache score 1-5 Tenderness score 0-3 in m. temporalis m. corrugator
3.72
0.73
2.52
0.80
-1.21
0.90
***
3.78
0.96
3.24
1.04
-0.54
1.01
*
1.36 1.36
0.92 0.75
0.84 0.74
0.81 0.70
-0.52 -0.62
1.0 0.68
** ***
1.75 1.68
0.86 0.78
1.41 1.57
1.00 0.92
-0.34 -0.11
0.76 0.89
N.S.
2.14 1.00
0.77 0.89
2.09 0.91
0.75 0.88
-0.05 -0.09
0.69 0.61
N.S. N.S.
2.23 2.66
0.86 0.54
1.63 0.23
0.95 0.90
-0.59 -0.43
0.78 0.78
**
m. orbicularis oculi 1.69 0.93 1.22 1.00 -0.47 m. masseter 0.91 0.91 0.47 0.81 -0.45 m. sternocleido mastoideus 1.86 0.96 1.24 0.93 -0.62 m. trapezius 2.79 0.37 0.02 0.90 -0.78 N.S. = not significant; * p < 0.05; ** p < 0.01; ** p < 0.001.
0.79 0.71 1.03 0.86
** ** ** ***
*
*
Table 2. Muscle tenderness (score 0-3) in patients before treatment and controls. Patients Controls n = 59 n = 30 Muscles Mean SD Mean SD p m. temporalis m. corrugator m. orbicularis m. masseter m. sternocleido mastoideus m. trapezius *** p < 0.001.
1.53 1.50 1.92 0.92 2.01
0.96 0.80 0.89 0.88 0.95
0.05 0.03 0.25 0.08 0.15
0.04 0.13 0.41 0.23 0.30
***
2.69
0.49
0.16
0.72
***
*** *** *** ***
Table 3. Correlation between headache intensity and muscle tenderness studied before treatment. Variables Tenderness of r p m. temporalis 0.29 m. corrugator 0.25 m. orbicularis 0.05 m. masseter 0.28 m. sternocleido mastoideus 0.25 m. trapezius 0.37 average tenderness 0.34 r = Pearson correlation coefficient. N.S. = not significant; * p < 0.05; ** p < 0.01.
*
N.S. N.S. *
N.S. ** **
muscles and the intensity of headache showed a significant correlation (p < 0.01) (Table 3). After treatment, muscle tenderness was significantly reduced for all tested muscles in the physiotherapy group. In the acupuncture group, only the tenderness of the sternocleidomastoid, temporal and trapezius muscles was significantly reduced (Table 1). The physiotherapy group was significantly better than the acupuncture group after treatment with respect to tenderness of the corrugator, orbicularis occuli and masseter muscles (p < 0.05). Table 4. Neck mobility in patients before treatment and controls. Patients Controls n = 59 n = 30 Neck mobility Mean SD Mean SD p Extension 73° 17° 79° 12° N.S. Flexion 58° 11° 60° 9° N.S. Lateral flexion 42° 8° 45° 6° N.S. Rotation 71° 15° N.S. = not significant; ** p < 0.01.
79°
7°
**
Cervical spine mobility Before treatment, rotation was significantly reduced in patients compared with controls while other neck mobilities did not differ (Table 4). The limitation of neck rotation was not influenced by either of the two modes of treatment. Intake of analgesics The intake of analgesics (ASA and paracetamol) was markedly reduced in the physiotherapy group while there was only a slight reduction in the acupuncture group (Fig. 3). Discussion
This study indicated that patients with ten-
sion headache treated with acupuncture or physiotherapy obtained a reduction of headache intensity and a decrease in tender points but no effect on the limited neck mobility. The improvement was most pronounced in the physiotherapy group. The reduction of the intake of analgesics in the physiotherapy group may be an expression of the reduction of pain by the treatment. It is probable, however, that the physiotherapist was more anxious and energetic than the acupuncturists in persuading the patients to reduce their intake of analgesics. Merely reducing analgesics may have reduced the pain (4). One might wonder whether the effects are due to specific neurophysiological mechanisms or unspecific placebo effects. The present study may be influenced by various kinds of bias. The invitation to participate, the professional supervision and, in the case of acupuncture, the mysterious power of an exotic treatment may all have fostered a positive placebo effect. In addition, the observer may have been biased. It is assumed that the placebo effect might explain up to 35% of pain reduction during treatment (18). Muscle stretching, automassage, TENS, acupuncture and placebo may employ a common mechanism since all are probably to some extent mediated by release of endorphine (19). The unspecific placebo effect may therefore act as a synergistic integrated and inseparable component. The patients in the study had a highly significantly increased level of muscle tenderness compared with controls. But tenderness alone cannot establish the diagnosis of tension headache since tenderness of pericranial muscles accompanies most headaches irrespective of the cause, e.g. headache related to sinuses, eyes, ears, teeth, the masticatory system or the neck and also migraine and headache caused by an increased intra-cranial pressure. Especially difficult is the distinction from primary fibromyalgia, in which, however, the tender areas do not only involve the head and neck (20). Surprisingly, not all of the patients and none of the controls were aware of their tender points. A possible explanation is that there are latent tender points which are painful only when they are palpated. An active tender point, on the other hand, produces pain on motion as well as at rest (7). The tenderness, expressed as the average score percentage of the total maximum score, was 6.7% for the controls and 59.2% for the patients. The corresponding values in the study of Langemark and Olesen (8) using the same palpation technique and registration method were 11.7% and 66.7%. The obvious similarity of the results indicates that the reproducibility of the palpation method is high when used by trained investigators. The relationship between muscle tenderness and headache is unclear. The headache evidently covers larger areas than the tender points and sometimes appears at sites remote from the tender areas. The explanation of some authors is that the headache is referred pain from the tender muscles (7).
The exact mechanism for referred pain is far from resolved. The convergence projection mechanism (21) is the one usually cited and can occur when cutaneous afferents and muscle afferents converge on the same central neuron. It is then assumed that the sensory cortex misinterprets the nociceptor responses from the muscles as coming from cutaneous structures. It is notable that only 15 of 43 patients with temporal headache in the present study had tender points above grade 2 in the temporal area but all had severe tender points (above grade 2) in the trapezius or sternocleidomastoid muscles (Fig. 2). Headache originating in the neck was first described by Barrè (22) in 1925. He introduced the term "syndrome cervical sympathique posterieur", thereby linking headache with a presumed deficiency of sympathetic activity in the neck region. Sjaastad (23) introduced the term "cervicogenic headache" without specifying a certain anatomical structure as the source of the pain. The symptoms are very close to those of tension headache but patients with cervicogenic headache can provoke their headache by head movements and there is a painful limitation of their neck mobility. The patients in this study could not provoke their headaches in any obvious way by head movements but there was a slight reduction of their neck mobility compared with controls. In this study, it was not possible to predict whether a patient would improve with the treatment from the intensity of the headache, the muscle tenderness or the neck mobility. It is possible that psychological tests and a long-term follow-up might disclose such predictive factors (24). The clinical conclusion of the study so far is that both acupuncture and physiotherapy could be used with a high degree of success in patients with tension headache. The somewhat better effect of physiotherapy might be due to the fact that the physiotherapy programme not only aims to give symptomatic pain relief but also includes measures to eliminate or reduce causative factors. Acknowledgements.-The study was supported by grants from Renee Eanders Hjälpfond and the Swedish Fund for Scientific Research Without Animal Experiments. References
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Jane Carlsson, Astrid Fahlcrantz, Lars-Erik Augustinsson
CEPHALALGIA Carlsson J, Fahlcrantz A, Augustinsson L-E. Muscle tenderness in tension headache treated with acupuncture or physiotherapy. Cephalalgia 1990;10:131-41. Oslo. ISSN 0333-1024 Sixty-two female patients with chronic tension headache were randomized into two treatment groups-acupuncture and physiotherapy. The intensity of headache, muscle tenderness and neck mobility was assessed before and after treatment. Thirty healthy women were used for comparison. Before treatment it was found that muscle tenderness was increased and neck rotation was reduced in the patient group compared with controls. There was a significant correlation between the intensity of headache and muscle tenderness. After treatment, the intensity of headache and muscle tenderness were reduced in both treatment groups. The headache was more improved in the physiotherapy group, and there was a marked reduction in the intake of analgesics. The tenderness was reduced in all muscles tested in the physiotherapy group but only in some of the muscles after acupuncture. The limitation of neck rotation was not influenced by either treatment. • Acupuncture, muscle tenderness, neck mobility, physiotherapy, tension headache Jane Carlsson, Department of Neurology; Astrid Fahlcrantz, Department of Physiotherapy; Lars-Erik Augustinsson, Department of Neurosurgery; all at the University of Göteborg, Sahlgrenska sjukhuset, S-413 45 Göteborg, Sweden; Accepted 17 April 1990 Tension headache has a multifactorial aetiology including both somatic and psychological factors (1). Monotonous work and unsuitable working positions are known causative factors. The headache is usually made worse by anxiety, stress and noise. Most patients are conscious of the fact that they are never really relaxed. According to Lance (2), approximately one-third have symptoms of depression. Muscle contraction can occur as a secondary phenomenon, e.g. in response to pain originating in other head or neck structures (3). Many patients tend to increase their intake of analgesics, which, paradoxically, can increase the pain (4). The pathogenetic mechanisms underlying tension headache are not known. Sustained contraction of the muscles of the neck, head and face is considered a probable cause of pain (5). Frequent involvement of the neck musculature, expressed as limitation of neck movements, is also reported (3). Additional vasoconstriction in the contracted muscles is supposed to cause ischaemia with worsening of the pain (1). Some investigators, however, have not been able to show any significant difference in EMG recordings from the forehead and neck muscles in patients with tension headache and those of normal controls (6). Tenderness of pericranial muscles is present in most headache patients (7). Langemark and Olesen (8) have found a significant correlation between the intensity of tension headache and a total tenderness score. The term "tension headache" used in this article is synonymous with muscle contraction headache as defined by the Ad Hoc Committee of the US National Institute of Health in 1962 (9). The new operational criteria of the International Headache Society in 1988 (10) introduced the term "tension-type headache", which also includes patients with normal levels of muscle tenderness and in whom EMG of pericranial muscles shows normal levels of activity. Medical treatment with analgesics, anti-depressants and relaxants has been and is still frequently used. Acetylsalicylic acid is probably the most widely used drug but, to the best of our knowledge, its efficacy in tension headache has not been evaluated. A variety of non-pharmacological treatments
have been tried, such as behavioural therapy, psychotherapy, hypnosis and feedback techniques (11). General forms of physiotherapy have been tried but more specific programmes have also been presented (12, 13). It has also been suggested that acupuncture may be useful (14). The lack of consistency reported by different authors concerning the relationship between contraction of pericranial muscles, muscle tenderness and tension headache as well as the diversity of the mostly non-evaluated therapies initiated the present study, the aims of which were: 1. to compare the frequency and severity of tenderness in pericranial muscles and the range of neck mobility in patients with tension headache with the same variables in a healthy control group, and 2. to study whether the headache, the tenderness of the pericranial muscles and the limitation of neck movements can be reduced with physiotherapy and acupuncture and if so which treatment is more effective. Patients
Sixty-two consecutive female patients with chronic tension headache were invited to participate in the study. All of them had been examined at the outpatient clinics of the Department of Neurology and Neurosurgery. Sahlgrenska Hospital, Göteborg from March 1984 to November 1987. Only females between 18 and 60 years of age (mean age 34 years) were accepted for the study. Exclusion criteria were: malignant or other serious diseases, headache which had started in close temporal relation to an organic disorder and difficulty in understanding and speaking Swedish. Patients with generalized myalgia and headache as part of a fibromyalgic syndrome were also excluded. Each patient underwent a full neurological examination and at the same time a comprehensive history was taken. There were no neurological or muscular diseases causing disseminated or focal signs in any of the patients. The diagnosis of tension headache was based on the criteria established for muscle contraction headache by the NIH in 1962 (9). This type of headache appears almost daily as a constant tight pressing or bandlike sensation in the occipital, temporal and/or frontal areas. The pain is bilateral but not necessarily symmetrical. Twenty-three patients had a mixed type of headache-a combination of tension headache and migraine with a clear predominance of the tension headache. The migraine component was of a mild form, from three attacks a year up to one attack a month. The low frequency of migraine attacks made a post-treatment evaluation impossible in this communication. Thirty-one patients complained of dizzinesss. The duration of the headache varied between 6 months and 33 years (median duration 7 years). Four patients were receiving a disability pension, five patients were on sick leave and two were unemployed on entering the study. Many of the patients had taken analgesics, most often acetylsalicylic acid (ASA) and paracetamol. When the study started, 16 patients were taking a few tablets a week, 27 patients moderate daily doses and six patients were taking more than 5g (10 tablets) of ASA daily. Ten patients took no analgesics at all. Patients with migraine took various anti-migraine compounds. Five patients took 5-15 mg of diazepam daily on an irregular basis and two patients were on tricyclic antidepressants. The patients were
told not to take any analgesics on the day when the tests were performed. All but two of the patients had previously tried some therapy for their headache. Twenty-eight had been taking analgesics exclusively and 20 analgesics and some other therapy such as relaxation programmes, transcutaneous electrical nerve stimulation (TENS), zone therapy, ultrasound or acupuncture. Nine patients had tried more than three different therapies. The previous therapies had no or only temporary effect. The type and severity of the patients' headaches were evaluated in 30 patients before the treatment period started. The headache intensity was assessed on a visual analogue scale on two occasions with an interval of 5-7 weeks. It appeared that the headache intensity did not differ markedly between the two registrations. If an error of ±10 mm on the 100 mm scale is accepted, 24 patients were unchanged, 3 were improved and 3 had become worse. The patients were randomized into two groups. Thirty-one patients had acupuncture and 31 physiotherapy. Two patients did not come to the tests before treatment and one patient did not fulfil the inclusion criteria. All three had been randomized to acupuncture. A further five patients in the acupuncture group and two patients in the physiotherapy group dropped out. Of these, one moved abroad, one was pregnant and therefore not suitable for acupuncture, one could not cope because of abuse of alcohol and four interrupted the study due to lack of time. The drop-outs did not differ from the other patients with respect to the variables studied. This means that 23 patients in the acupuncture group and 29 patients in the physiotherapy group completed the study. The patients' informed consent to participation in the research project was obtained. A control group consisting of 30 healthy women aged from 19 to 56 years (mean age 36 years) selected from a non-clinical population was used for comparison. Methods
All patient tests were performed by one of the authors (AF), who did not take part in the treatment programme. The tests took place 3 to 8 weeks before the start of the treatment and were repeated 4 to 9 weeks after the termination of treatment. Intensity of the headache The patients were asked to rate the intensity of the headache before and after treatment. A five-point scale was used, with the following levels of pain intensity: 1 none or negligible, 2 mild, 3 moderate, 4 severe and 5 incapacitating headache. Muscle tenderness The degree of tenderness was evaluated by palpation of six pericranial muscles on each side of the head. The muscles were selected because they correspond to the location of headache, are superficial and are easy to find. The tenderness was assessed according to a four-point scale which corresponds well with the scale presented by Langemark and Olesen in 1987 (8). The following levels of pain intensity on palpation were used: 0 = no report of pain and no visible reactions, 1 = report of tenderness but no visible reaction, 2 = report of painful tenderness and visible reaction, 3 = report of severe pain and marked visible reaction, "jump sign" (7). The muscle sites chosen for palpation, depicted in Fig. 1, were as follows: 1. The origin of the superficial part of the masseter muscles at the anterior two-thirds of the lower border of the zygomatic arch. 2. The origin of the orbicularis oculi muscles at the medial corner of the eye. 3. The upper anterior part of the origin of the temporalis muscles. 4. The origin of the corrugator muscles at the medial end of the superciliary notch. 5. The insertion of the sternocleidomastoid muscles at the mastoid process. 6. The origin of the trapezius muscles at the external occipital protuberance. The subjects were placed in a relaxed recumbent position. The second and third fingers were used for palpation and the subject's
head was supported with the other hand. The palpation was done with small circulating, mildly pressing movements. The muscles were examined in the order given above. The mean values for each pair of the 12 palpated muscles were calculated. A total tenderness score (8) for each patient was obtained by adding the scores from all palpated sites, the maximum score being 12 x 3 = 36. Cervical spine mobility The neck mobility was measured with an inclinometer ("Myrin") (The Myrin inclinometer is produced by LIC, Svetsarvägen 4, 172 83 Solna, Sweden) (15). All movements, including flexion, extension, side flexion and rotation, were measured with the subject seated. She was instructed to sit straight up, right back into the chair, and to avoid opening her mouth during extension. During flexion/extension movements, a Velcro band was firmly fixed around the head above the eyebrows. The inclinometer was then placed on the band just above the ear, the zero point being lined up with the tragus. During side flexion, the inclinometer was placed, without moving the band, at the front of the head with the zero point lined up with the nose. During rotation, the inclinometer was placed on top of the head with the zero point lined up with the bridge of the nose. For each movement, the subject was instructed to move her head actively as far as she could. Care was taken to make sure that a pure movement of the head took place and movements of the shoulders or the back were minimized. Each movement was repeated twice and the best of the two readings recorded. In the control group, examination of the tenderness of pericranial muscles and the neck mobility was performed by two independently operating investigators in an attempt to assess the reliability of the methods. The two investigators had previously coordinated the techniques. Of 360 palpated sites, the two investigators reported equal values in 306 (85%) and of 180 measurements of neck mobility 163 recordings (91%) were within 15°. Both methods thus showed a high degree of reproducibility. In the patient groups, both tests were performed by one investigator. Statistical methods For comparison before and after treatment between variables measured within a separate treatment group, a linear non-parametric permutation test for paired observations was used. For comparison between the two treatment groups and between the treatment groups and controls, Fischer's non-parametric permutation test was used. For correlations between the different variables measured, Pitman's non-paramagnetic permutation test was used. Pearson product-moment correlation coefficient was used to describe the level of correlation between two variables (16). Treatment
Physiotherapy The therapy was given by a physiotherapist (J. C., one of the authors) who did not take part in the test programme. The treatment programme was specific for each patient. The goal was to teach the patient to handle any situation with as little physical tension as possible. The programme was divided into 10-12 sessions with an overlapping between different sessions. How much and what kind of information given was varied according to the patient's receptibility and motivation. The treatment extended over 2-3 months, with 1-2 sessions per week, each with 30-45 min of individual instruction. Session 1. History-taking including location, frequency, duration and quality of the headache. Possible factors leading to the headache, such as psychosocial stress, unsuitable working positions, monotonous work, craniomandibular disorders, etc., were discussed. The patient was instructed to avoid such causative factors, at least temporarily, in order to break the vicious circle of muscle spasm leading to pain, which in itself may lead to more muscle spasm.
Session 2. Inspection of the patient. This included observation of the patient's facial expression (whether she ground her teeth, wrinkled her forehead and/or narrowed her eyes) and standing position, sitting position and movement, especially the positioning of the head and shoulders. The mobility of the neck and shoulder was examined with the intention of finding tense and shortened muscles. This was the basis for the applied corrections of the patient's position during different activities. Session 3. The patient was told that she could obtain pain relief without analgesics. Massage, cryotherapy and TENS were used and managed by the patient herself. The patient was instructed to use these techniques daily at home in an individually adapted combination and at the same time reduce and eventually withdraw all intake of analgesics. Sessions 4 and 5. Relaxation of the whole body was performed according to a technique presented by Jacobsen (13), including two 10 min sessions of daily training at home. The intention was to make the patient aware of the difference between tense and relaxed muscles by practising contraction and relaxation of different muscles. The patient was instructed to start the training in a comfortable recumbent position in a peaceful environment. Eventually the difficulties in relaxing were increased by performing the training in the sitting position and in a less peaceful environment. Sessions 6 and 7. The contracted and tender muscles were dealt with specially. The muscle was contracted heavily for about 10 sec relaxed for 10 sec, then passively stretched for 20 sec. To help the patient to notice any warning sensation of tension, a piece of tape was placed on the skin over the contracted muscle(s). When the muscle started to contract, the patient felt the movement of the tape and could voluntarily stop the contraction and relax the muscle. Sessions 8 and 9. A final important step was to practise relaxation in everyday life. The patient must be aware of the way she stands, sits, walks and how she lies when sleeping. She must adopt a new and more economic pattern of use of the musculature and check that all muscles which are not essential for the task of the moment are in a state of relaxation. This applies to working situations such as writing, typing or speaking on the telephone as well as leisure activities such as reading, watching TV and sports. Session 10. When the patient had learned how to prevent the headache coming and to eliminate or reduce the headache once it had started, it was time to build up the patient's physical condition, including muscle strength, coordination, litheness and fitness. The training had to be planned according to an individually adapted programme which could be managed by the patient herself. Acupuncture Acupuncture was performed by two physicians using the same technique. One was one of the authors (L-E. A.), who did not take part in the test programme. The acupuncturist asked the patient about the type and site of the headache and examined the patient with respect to tender points in the pericranial musclature. He also explained the supposed physiological background to the effect of acupuncture in easily understandable terms. Standard 1.5 inch stainless steel electrodes were used. The needles were inserted perpendicularly to a depth where the s.c. Te Chi phenomenon occurs. In all patients, local points and one distal point were treated. The points are classical Chinese acupuncture points (17). The local points are the gall bladder (GB) meridian point numbers 20 and 21. Anatomically, GB20 corresponds to the major occipital nerve where it runs just medial to the mastoid process and GB21 to the middle of the upper border of the trapezius muscle. The distal points include the first dorsal interosseus muscle of the hands (LI 4). This point is called Hegu and is commonly used in traditional Chinese acupuncture for headache. Altogether six points were needled on each occasion. In patients
with a probable migrainous component in their tension headache, the following additional points were used: GB14 above the eyebrow, the extra points Tai Yang in the temporal region and Yin Tang between the eyebrows. At the first treatment session, the needles were inserted and twiddled by hand. From the second treatment on, electrical stimulation via the needles was used. The electrical parameters were frequency 1-2 Hz, pulse width 0.5 msec and an intensity high enough to cause comfortable contractions in the muscle-usually in the range of 4-7 volts. The length of each treatment session was at least 20 min. A standard trial period of 2-4 weeks was used. During this period, 4-5 single treatments were performed. If the patients hereafter reported clear pain relief, a further 4-5 treatments were given. The patients were asked to reduce their intake of analgesics as much as they considered possible. In a few patients, a slight vasovagal reaction was seen at the first treatment. Otherwise, no complications were noted. Results
Before treatment the values for muscle tenderness, intensity of headache and neck mobility were evenly distributed between the physiotherapy group and the acupuncture group. In the statistical analysis, the material was therefore considered homogeneous. Headache The location of headache before treatment is depicted in Fig. 2. After treatment, the headache was significantly reduced in both patient groups (Table 1). The headache intensity had become significantly lower in the physiotherapy group compared with the acupuncture group (p < 0.05). Patients who reported reduced intensity of their headache did not differ from those who did not with respect to the pretreatment levels of headache intensity, muscle tenderness or neck mobility.
Muscle tenderness Before treatment, the tenderness of the palpated muscles was significantly higher in the patient group compared with the controls (Table 2). There were no tender points above grade 2 among the controls. All patients had at least five tender points and there was a bilateral distribution of the tenderness in all patients. The tenderness was most pronounced on the right side of the head in the temporal, orbicularis oculi, sternocleidomastoid (p < 0.05) and corrugator (p < 0.01) muscles, while there was no difference between right and left side for the masseter and trapezius muscles. The average score for the controls was 2.4 and for the patients 21.3, representing 6.7% and 59.2% when calculated as a percentage of the maximal total score. A significant correlation was found between the intensity of headache and the tenderness of the temporal, masseter (p < 0.05) and trapezius muscles (p < 0.01). The average tenderness of all palpated
Table 1. Intensity of headache and muscle tenderness before and after treatment with physiotherapy and acupuncture. Physiotherapy Acupuncture Before After Before After treatment treatment Difference treatment treatment Difference Mean SD Mean SD Mean SD p Mean SD Mean SD Mean SD p Intensity of headache score 1-5 Tenderness score 0-3 in m. temporalis m. corrugator
3.72
0.73
2.52
0.80
-1.21
0.90
***
3.78
0.96
3.24
1.04
-0.54
1.01
*
1.36 1.36
0.92 0.75
0.84 0.74
0.81 0.70
-0.52 -0.62
1.0 0.68
** ***
1.75 1.68
0.86 0.78
1.41 1.57
1.00 0.92
-0.34 -0.11
0.76 0.89
N.S.
2.14 1.00
0.77 0.89
2.09 0.91
0.75 0.88
-0.05 -0.09
0.69 0.61
N.S. N.S.
2.23 2.66
0.86 0.54
1.63 0.23
0.95 0.90
-0.59 -0.43
0.78 0.78
**
m. orbicularis oculi 1.69 0.93 1.22 1.00 -0.47 m. masseter 0.91 0.91 0.47 0.81 -0.45 m. sternocleido mastoideus 1.86 0.96 1.24 0.93 -0.62 m. trapezius 2.79 0.37 0.02 0.90 -0.78 N.S. = not significant; * p < 0.05; ** p < 0.01; ** p < 0.001.
0.79 0.71 1.03 0.86
** ** ** ***
*
*
Table 2. Muscle tenderness (score 0-3) in patients before treatment and controls. Patients Controls n = 59 n = 30 Muscles Mean SD Mean SD p m. temporalis m. corrugator m. orbicularis m. masseter m. sternocleido mastoideus m. trapezius *** p < 0.001.
1.53 1.50 1.92 0.92 2.01
0.96 0.80 0.89 0.88 0.95
0.05 0.03 0.25 0.08 0.15
0.04 0.13 0.41 0.23 0.30
***
2.69
0.49
0.16
0.72
***
*** *** *** ***
Table 3. Correlation between headache intensity and muscle tenderness studied before treatment. Variables Tenderness of r p m. temporalis 0.29 m. corrugator 0.25 m. orbicularis 0.05 m. masseter 0.28 m. sternocleido mastoideus 0.25 m. trapezius 0.37 average tenderness 0.34 r = Pearson correlation coefficient. N.S. = not significant; * p < 0.05; ** p < 0.01.
*
N.S. N.S. *
N.S. ** **
muscles and the intensity of headache showed a significant correlation (p < 0.01) (Table 3). After treatment, muscle tenderness was significantly reduced for all tested muscles in the physiotherapy group. In the acupuncture group, only the tenderness of the sternocleidomastoid, temporal and trapezius muscles was significantly reduced (Table 1). The physiotherapy group was significantly better than the acupuncture group after treatment with respect to tenderness of the corrugator, orbicularis occuli and masseter muscles (p < 0.05). Table 4. Neck mobility in patients before treatment and controls. Patients Controls n = 59 n = 30 Neck mobility Mean SD Mean SD p Extension 73° 17° 79° 12° N.S. Flexion 58° 11° 60° 9° N.S. Lateral flexion 42° 8° 45° 6° N.S. Rotation 71° 15° N.S. = not significant; ** p < 0.01.
79°
7°
**
Cervical spine mobility Before treatment, rotation was significantly reduced in patients compared with controls while other neck mobilities did not differ (Table 4). The limitation of neck rotation was not influenced by either of the two modes of treatment. Intake of analgesics The intake of analgesics (ASA and paracetamol) was markedly reduced in the physiotherapy group while there was only a slight reduction in the acupuncture group (Fig. 3). Discussion
This study indicated that patients with ten-
sion headache treated with acupuncture or physiotherapy obtained a reduction of headache intensity and a decrease in tender points but no effect on the limited neck mobility. The improvement was most pronounced in the physiotherapy group. The reduction of the intake of analgesics in the physiotherapy group may be an expression of the reduction of pain by the treatment. It is probable, however, that the physiotherapist was more anxious and energetic than the acupuncturists in persuading the patients to reduce their intake of analgesics. Merely reducing analgesics may have reduced the pain (4). One might wonder whether the effects are due to specific neurophysiological mechanisms or unspecific placebo effects. The present study may be influenced by various kinds of bias. The invitation to participate, the professional supervision and, in the case of acupuncture, the mysterious power of an exotic treatment may all have fostered a positive placebo effect. In addition, the observer may have been biased. It is assumed that the placebo effect might explain up to 35% of pain reduction during treatment (18). Muscle stretching, automassage, TENS, acupuncture and placebo may employ a common mechanism since all are probably to some extent mediated by release of endorphine (19). The unspecific placebo effect may therefore act as a synergistic integrated and inseparable component. The patients in the study had a highly significantly increased level of muscle tenderness compared with controls. But tenderness alone cannot establish the diagnosis of tension headache since tenderness of pericranial muscles accompanies most headaches irrespective of the cause, e.g. headache related to sinuses, eyes, ears, teeth, the masticatory system or the neck and also migraine and headache caused by an increased intra-cranial pressure. Especially difficult is the distinction from primary fibromyalgia, in which, however, the tender areas do not only involve the head and neck (20). Surprisingly, not all of the patients and none of the controls were aware of their tender points. A possible explanation is that there are latent tender points which are painful only when they are palpated. An active tender point, on the other hand, produces pain on motion as well as at rest (7). The tenderness, expressed as the average score percentage of the total maximum score, was 6.7% for the controls and 59.2% for the patients. The corresponding values in the study of Langemark and Olesen (8) using the same palpation technique and registration method were 11.7% and 66.7%. The obvious similarity of the results indicates that the reproducibility of the palpation method is high when used by trained investigators. The relationship between muscle tenderness and headache is unclear. The headache evidently covers larger areas than the tender points and sometimes appears at sites remote from the tender areas. The explanation of some authors is that the headache is referred pain from the tender muscles (7).
The exact mechanism for referred pain is far from resolved. The convergence projection mechanism (21) is the one usually cited and can occur when cutaneous afferents and muscle afferents converge on the same central neuron. It is then assumed that the sensory cortex misinterprets the nociceptor responses from the muscles as coming from cutaneous structures. It is notable that only 15 of 43 patients with temporal headache in the present study had tender points above grade 2 in the temporal area but all had severe tender points (above grade 2) in the trapezius or sternocleidomastoid muscles (Fig. 2). Headache originating in the neck was first described by Barrè (22) in 1925. He introduced the term "syndrome cervical sympathique posterieur", thereby linking headache with a presumed deficiency of sympathetic activity in the neck region. Sjaastad (23) introduced the term "cervicogenic headache" without specifying a certain anatomical structure as the source of the pain. The symptoms are very close to those of tension headache but patients with cervicogenic headache can provoke their headache by head movements and there is a painful limitation of their neck mobility. The patients in this study could not provoke their headaches in any obvious way by head movements but there was a slight reduction of their neck mobility compared with controls. In this study, it was not possible to predict whether a patient would improve with the treatment from the intensity of the headache, the muscle tenderness or the neck mobility. It is possible that psychological tests and a long-term follow-up might disclose such predictive factors (24). The clinical conclusion of the study so far is that both acupuncture and physiotherapy could be used with a high degree of success in patients with tension headache. The somewhat better effect of physiotherapy might be due to the fact that the physiotherapy programme not only aims to give symptomatic pain relief but also includes measures to eliminate or reduce causative factors. Acknowledgements.-The study was supported by grants from Renee Eanders Hjälpfond and the Swedish Fund for Scientific Research Without Animal Experiments. References
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