Catechol-O-Methyltransferase (COMT) rs4680 Val158Met Polymorphism is Associated With Widespread Pressure Pain Sensitivity and Depression in Women With Chronic, but not Episodic, Tension-Type Headache.

OBJECTIVES: The aims of this study were: (1) to investigate the association between the rs4680 Val158Met polymorphism in frequent episodic tension-type headache (FETTH) and chronic tension-type headache (CTTH); and (2) to analyze the association between the rs4680 Val158Met polymorphism with clinical, psychological, or psychophysical variables. METHODS: In total, 50 women with FETTH, 50 with CTTH, and 50 matched headache-free women participated. After amplifying Val158Met polymorphism by polymerase chain reaction, the genotype frequencies and allele distributions based on restriction fragment length polymorphism were assessed. Participants were classified according to the Val158Met polymorphism rs4680 genotype (Val/Val, Val/Met, or Met/Met). A headache diary collected clinical features. Disability (Headache Disability Inventory), sleep quality (Pittsburgh Sleep Quality Index), and depression/anxiety levels (Hospital Anxiety and Depression Scale) were also assessed. Pressure pain thresholds were assessed bilaterally over the temporalis, upper trapezius, second metacarpal, and tibialis anterior by a blinded assessor. RESULTS: The distribution of rs4680 Val158Met genotype was not significantly different between women with/without headache (P=0.796). No differences in headache features, disability, anxiety, or sleep quality were observed depending on the rs4680 Val158Met genotype. Women with CTTH, but not FETTH, carrying the Met/Met genotype had lower widespread pressure pain thresholds and higher depressive symptoms than those with Val/Val or Val/Met genotype (P<0.05). CONCLUSIONS: The Val158Met polymorphism (rs4680) does not appear to be involved in predisposition to tension-type headache; however, this genetic factor may be involved in the pathogenesis expression of CTTH, as greater pressure pain sensitivity and higher depressive levels were found in CTTH carrying the Met/Met genotype.

Trigger points are associated with widespread pressure pain sensitivity in people with tension-type headache.

Objective To investigate the association between trigger points (TrPs) and widespread pressure pain sensitivity in people with tension-type headache (TTH) and to determine if this association is different between frequent episodic (FETTH) or chronic (CTTH) headache. Design A cross-sectional study. Methods One hundred and fifty-seven individuals (29% male) with TTH participated. Clinical features of headache, i.e., intensity, duration, and frequency, were recorded in a headache diary. Active and latent TrPs were bilaterally explored in the temporalis, masseter, suboccipital, upper trapezius, sternocleidomastoid, and splenius capitis muscles. Pressure pain thresholds (PPT) were assessed over the trigeminal area (i.e., temporalis muscle), extra-trigeminal (i.e., C5/C6 zygapophyseal joint), and two distant pain-free points (i.e., second metacarpal and tibialis anterior muscle). Results Eighty (51%) patients were classified as FETTH, whereas 77 (49%) were classified as CTTH. No differences in the number of either active or latent TrPs (all p > 0.171) or widespread pressure pain sensitivity (all p > 0.351) were observed between FETTH and CTTH groups. The number of active and latent TrPs was significantly and negatively associated with PPTs: The higher the number of active or latent TrPs, the lower the widespread PPT, and the more generalized sensitization. This association was stronger within the FETTH group than the CTTH group. Conclusions This study found that the number of TrPs in head and neck/shoulder muscles was associated with widespread pressure hypersensitivity independently of the frequency of headache.

Development of a clinical prediction rule for identifying women with tension-type headache who are likely to achieve short-term success with joint mobilization and muscle trigger point therapy.

OBJECTIVE: To identify prognostic factors from the history and physical examination in women with tension-type headache (TTH) who are likely to experience self-perceived clinical improvement following a multimodal physical therapy session including joint mobilization and muscle trigger point (TrP) therapies. BACKGROUND: No definitive therapeutic intervention is available for TTH. It would be useful for clinicians to have a clinical prediction rule for selecting which TTH patients may experience improved outcomes following a multimodal physical therapy program. METHODS: Women diagnosed with pure TTH by 3 experienced neurologists according to the International Headache Society criteria from different neurology departments were included. They underwent a standardized examination (neck mobility, pressure pain thresholds, total tenderness score, presence of muscle TrPs, Medical Outcomes Study 36-Item Short Form, the Neck Disability Index [NDI], the Beck Depression Inventory, and the Headache Disability Inventory) and then a multimodal physical therapy session including joint mobilization and TrP therapies. The treatment session included a 30-second grade III or IV central posterior-anterior nonthrust mobilization applied from T4 to T1 thoracic vertebrae, at C7-T1 cervico-thoracic junction and C1-C2 vertebrae for an overall intervention time of 5 minutes Different TrP techniques, particularly soft tissue stroke, pressure release, or muscle energy were applied to head and neck-shoulder muscles (temporalis, suboccipital, upper trapezius, splenius capitis, semispinalis capitis, sternocleidomastoid) to inactivate active muscle TrPs. Participants were classified as having achieved a successful outcome 1 week after the session based on their self-perceived recovery. Potential prognostic variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for prediction of success. RESULTS: Data for 76 subjects were included in the analysis, of which 36 experienced a successful outcome (48%). Eight prognostic variables were retained in the regression model: mean age <44.5 years, presence of left sternocleidomastoid TrP, presence of suboccipital TrP, presence of left superior oblique muscle TrP, cervical rotation to the left > 69°, total tenderness score <20.5, NDI <18.5, referred pain area of right upper trapezius muscle TrP >42.23. CONCLUSIONS: The current clinical prediction rule may allow clinicians to make an a priori identification of women with TTH who are likely to experience short-term self-report improvement with a multimodal session including joint mobilizations and TrP therapies. Future studies are necessary to validate these findings.

Multiple active myofascial trigger points and pressure pain sensitivity maps in the temporalis muscle are related in women with chronic tension type headache.

OBJECTIVE: To describe the common locations of active trigger points (TrPs) in the temporalis muscle and their referred pain patterns in chronic tension type headache (CTTH), and to determine if pressure sensitivity maps of this muscle can be used to describe the spatial distribution of active TrPs. METHODS: Forty women with CTTH were included. An electronic pressure algometer was used to assess pressure pain thresholds (PPT) from 9 points over each temporalis muscle: 3 points in the anterior, medial and posterior part, respectively. Both muscles were examined for the presence of active TrPs over each of the 9 points. The referred pain pattern of each active TrP was assessed. RESULTS: Two-way analysis of variance detected significant differences in mean PPT levels between the measurement points (F=30.3; P<0.001), but not between sides (F=2.1; P=0.2). PPT scores decreased from the posterior to the anterior column (P<0.001). No differences were found in the number of active TrPs (F=0.3; P=0.9) between the dominant side the nondominant side. Significant differences were found in the distribution of the active TrPs (chi2=12.2; P<0.001): active TrPs were mostly found in the anterior column and in the middle of the muscle belly. The analysis of variance did not detect significant differences in the referred pain pattern between active TrPs (F=1.1, P=0.4). The topographical pressure pain sensitivity maps showed the distinct distribution of the TrPs indicated by locations with low PPTs. CONCLUSIONS: Multiple active TrPs in the temporalis muscle were found, particularly in the anterior column and in the middle of the muscle belly. Bilateral posterior to anterior decreased distribution of PPTs in the temporalis muscle in women with CTTH was found. The locations of active TrPs in the temporalis muscle corresponded well to the muscle areas with lower PPT, supporting the relationship between multiple active muscle TrPs and topographical pressure sensitivity maps in the temporalis muscle in women with CTTH.