Josué Fernández-Carnero

Bilateral Widespread Mechanical Pain Sensitivity in Women With Myofascial Temporomandibular Disorder: Evidence of Impairment in Central Nociceptive Processing

UNLABELLED Our aim was to investigate bilateral, widespread pressure-pain hypersensitivity in nerve, muscle, and joint tissues in women with myofascial temporomandibular disorders (TMD) without concomitant comorbid conditions. Twenty women with myofascial TMD (aged 20 to 28 years old), and 20 healthy matched women (aged 20 to 29 years), were recruited. Pressure-pain thresholds (PPT) were bilaterally assessed over supra-orbital (V1), infra-orbital (V2), mental (V3) nerves, median (C5), radial (C6) and ulnar (C7) nerve trunks, the C5-C6 zygapophyseal joint, the lateral pole of the temporo mandibular joint (TMJ), and the tibialis anterior muscle in a blinded design. The results showed that PPTs were significantly decreased bilaterally over the supra-orbital, infra-orbital, and mental nerves, median, ulnar, and radial nerve trunks, the lateral pole of the TMJ, the C5-C6 zygapophyseal joint, and the tibialis anterior muscle in patients with myofascial TMD as compared to healthy controls (all sites: P < .001). There were no significant differences in the magnitude of PPT decreases between the trigeminal and extratrigeminal test sites. PPT over the mental nerve, the TMJ, C5-C6 zygapophyseal joint and tibialis anterior muscle were negatively correlated to both duration of pain symptoms and TMD pain intensity (P < .05). Our findings revealed bilateral, widespread pressure hypersensitivity in women presenting with myofascial TMD, suggesting that widespread central sensitization is involved in myofascial TMD women. PERSPECTIVE This article reveals the presence of bilateral and widespread pressure-pain hypersensitivity in women with myofascial TMD, suggesting that widespread central sensitization is involved in myofascial TMD. This finding has implications for development of management strategies.

Widespread mechanical pain hypersensitivity as sign of central sensitization in unilateral epicondylalgia: a blinded, controlled study

ObjectiveThe aim of this study was to investigate whether generalized deep tissue hyperalgesia exists in patients with chronic unilateral lateral epicondylalgia (LE). MethodsA total of 26 LE patients (10 males and 16 females, aged 25 to 63 y) and 20 healthy comparable matched controls (aged 26 to 61 y) were recruited and pressure pain threshold (PPT) was assessed bilaterally over the median, ulnar, and radial nerve trunks, the lateral epicondyle, C5-C6 zygapophyseal joint, and the tibialis anterior muscle in a blind design. ResultsPPT was significantly decreased bilaterally over the median, ulnar, and radial nerve trunks, the lateral epicondyle, the C5-C6 zygapophyseal joint, and tibialis anterior muscle in patients with LE than healthy controls (all P<0.001). PPTs over those measured points was negatively related to current elbow pain intensity (all P<0.05). A more significant decrease in PPTs were present in females (all P<0.05). ConclusionsThis revealed a widespread mechanical hypersensitivity in patients with LE, which suggest that central sensitization mechanisms are involved in patients with unilateral LE. The generalized decrease in PPT levels was associated with elbow pain intensity, supporting a role of peripheral sensitization mechanisms in the initiation or maintenance of central sensitization mechanisms. In addition, females may be more prone to the development of generalized mechanical hypersensitivity.

Bilateral widespread mechanical pain sensitivity in carpal tunnel syndrome: evidence of central processing in unilateral neuropathy

The aim of this study was to investigate whether bilateral widespread pressure hypersensitivity exists in patients with unilateral carpal tunnel syndrome. A total of 20 females with carpal tunnel syndrome (aged 22-60 years), and 20 healthy matched females (aged 21-60 years old) were recruited. Pressure pain thresholds were assessed bilaterally over median, ulnar, and radial nerve trunks, the C5-C6 zygapophyseal joint, the carpal tunnel and the tibialis anterior muscle in a blinded design. The results showed that pressure pain threshold levels were significantly decreased bilaterally over the median, ulnar, and radial nerve trunks, the carpal tunnel, the C5-C6 zygapophyseal joint, and the tibialis anterior muscle in patients with unilateral carpal tunnel syndrome as compared to healthy controls (all, P < 0.001). Pressure pain threshold was negatively correlated to both hand pain intensity and duration of symptoms (all, P < 0.001). Our findings revealed bilateral widespread pressure hypersensitivity in subjects with carpal tunnel syndrome, which suggest that widespread central sensitization is involved in patients with unilateral carpal tunnel syndrome. The generalized decrease in pressure pain thresholds associated with pain intensity and duration of symptoms supports a role of the peripheral drive to initiate and maintain central sensitization. Nevertheless, both central and peripheral sensitization mechanisms are probably involved at the same time in carpal tunnel syndrome.

IMMEDIATE HYPOALGESIC AND MOTOR EFFECTS AFTER A SINGLE CERVICAL SPINE MANIPULATION IN SUBJECTS WITH LATERAL EPICONDYLALGIA

OBJECTIVE The purpose of this study is to investigate the immediate effects of a single cervical spine manipulation and a manual contact intervention (MCI) on pressure pain thresholds (PPTs) and thermal pain thresholds over the elbow region and pain-free grip (PFG) force in patients with lateral epicondylalgia (LE). METHODS A repeated measures, crossover, single-blinded randomized study was done. Ten patients with LE (5 female) aged from 30 to 49 years (mean, 42; SD, 6 years) participated in this study. Subjects attended 2 experimental sessions on 2 separate days at least 48 hours apart. At each session, participants received either a manipulative intervention or MCI assigned in a random fashion. Pressure pain threshold and hot and cold pain thresholds (HPT and CPT, respectively) over the lateral epicondyle of both elbows was assessed preintervention and 5 minutes postintervention by an examiner blinded to the treatment allocation of the patients. In addition, PFG on the affected arm and maximum grip force on the unaffected side were also assessed. A 3-way analysis of variance (ANOVA) with time (pre-post) and side (ipsilateral, contralateral to the intervention) as within-subjects variable and intervention (manipulation or MCI) as between-subjects variable was used to evaluate changes in PPT, HPT, CPT, or PFG. RESULTS The ANOVA detected a significant effect for time (F = 37.2, P < .001) and a significant interaction between intervention and time (F = 25.1, P < .001) for PPT levels. Post hoc revealed that the manipulative intervention produced a greater increase of PPT in both sides when compared with MCI (P < .001). The ANOVA did not detect significant effects for time (F = 2.7, P > .2), intervention (F = 2.8, P > .2), or side (F = 0.9, P > .4) for HPT. Again, no significant effects for time (F = 0.8, P > .4), side (F = 0.6, P > .4), or intervention (F = 0.8, P > .5) was found for CPT. Finally, a significant interaction between intervention and time (F = 9.4, P = .004) and between time * side * intervention (F = 18.2, P < .001) was found for grip force. Post hoc analysis revealed that the cervical manipulation produced an increase of PFG on the affected side as compared with the MCI (P < .001). CONCLUSIONS The application of a manipulation at the cervical spine produced an immediate bilateral increase in PPT in patients with LE. No significant changes for HPT and CPT were found. Finally, cervical manipulation increased PFG on the affected side, but not the maximum grip force on the unaffected arm. Future studies with larger sample sizes are required to examine the effects of thrust manipulation on PPT, HPT, CPT, or PFG.

The effects of manual therapy and exercise directed at the cervical spine on pain and pressure pain sensitivity in patients with myofascial temporomandibular disorders

No studies have investigated the effects of the treatments directed at the cervical spine in patients with temporomandibular disorders (TMD). Our aim was to investigate the effects of joint mobilization and exercise directed at the cervical spine on pain intensity and pressure pain sensitivity in the muscles of mastication in patients with TMD. Nineteen patients (14 females), aged 19-57 years, with myofascial TMD were included. All patients received a total of 10 treatment session over a 5-week period (twice per week). Treatment included manual therapy techniques and exercise directed at the cervical spine. Outcome measures included bilateral pressure pain threshold (PPT) levels over the masseter and temporalis muscles, active pain-free mouth opening (mm) and pain (Visual Analogue Scale) and were all assessed pre-intervention, 48 h after the last treatment (post-intervention) and at 12-week follow-up period. Mixed-model anovas were used to examine the effects of the intervention on each outcome measure. Within-group effect sizes were calculated in order to assess clinical effect. The 2 x 3 mixed model anova revealed significant effect for time (F = 77.8; P < 0.001) but not for side (F = 0.2; P = 0.7) for changes in PPT over the masseter muscle and over the temporalis muscle (time: F = 66.8; P < 0.001; side: F = 0.07; P = 0.8). Post hoc revealed significant differences between pre-intervention and both post-intervention and follow-up periods (P < 0.001) but not between post-intervention and follow-up period (P = 0.9) for both muscles. Within-group effect sizes were large (d > 1.0) for both follow-up periods in both muscles. The anova found a significant effect for time (F = 78.6; P < 0.001) for changes in pain intensity and active pain-free mouth opening (F = 17.1; P < 0.001). Significant differences were found between pre-intervention and both post-intervention and follow-up periods (P < 0.001) but not between the post-intervention and follow-up period (P > 0.7). Within-group effect sizes were large (d > 0.8) for both post-intervention and follow-up periods. The application of treatment directed at the cervical spine may be beneficial in decreasing pain intensity, increasing PPTs over the masticatory muscles and an increasing pain-free mouth opening in patients with myofascial TMD.

Bilateral Mechanical-Pain Sensitivity Over the Trigeminal Region in Patients With Chronic Mechanical Neck Pain

UNLABELLED The aim of this study was to investigate bilateral pressure-pain sensitivity over the trigeminal region, the cervical spine, and the tibialis anterior muscle in patients with mechanical chronic neck pain. Twenty-three patients with neck pain (56% women), aged 20 to 37 years old, and 23 matched controls (aged 20 to 38 years) were included. Pressure pain thresholds (PPTs) were bilaterally assessed over masseter, temporalis, and upper trapezius muscles, the C5-C6 zygapophyseal joint, and the tibialis anterior muscle in a blinded design. The results showed that PPT levels were significantly decreased bilaterally over the masseter, temporalis, and upper trapezius muscles, and also the C5-C6 zygapophyseal joint (P < .001), but not over the tibialis anterior muscle (P = .4) in patients with mechanical chronic neck pain when compared to controls. The magnitude of PPT decreases was greater in the cervical region as compared to the trigeminal region (P < .01). PPTs over the masseter muscles were negatively correlated to both duration of pain symptoms and neck-pain intensity (P < .001). Our findings revealed pressure-pain hyperalgesia in the trigeminal region in patients with mechanical chronic neck pain, suggesting spreading of sensitization to the trigeminal region in this patient population. PERSPECTIVE This article reveals the presence of bilateral pressure-pain hypersensitivity in the trigeminal region in patients with idiopathic neck pain, suggesting a sensitization process of the trigemino-cervical nucleus caudalis in this population. This finding has implications for development of management strategies.

Exploration of the Extent of Somato-Sensory Impairment in Patients with Unilateral Lateral Epicondylalgia

UNLABELLED There is evidence suggesting an important role of nociceptive sensitization in lateral epicondylalgia (LE). Our aim was to explore somato-sensory changes in patients with unilateral LE to better understand this musculoskeletal condition. Twelve patients (6 female) with LE with a mean (SD) age 47 (10) years, and 16 controls (7 female), aged 41 (9) years were tested. The following somato-sensory parameters were assessed: pressure-pain threshold (PPT), heat- and cold-pain thresholds, thermal, cold- and vibration-detection thresholds. All these tests were bilaterally assessed over the lateral epicondyle (affected/unaffected in patients; dominant/nondominant in controls) and at the dorsal-lateral surface of the wrist in all patients and controls. The results showed that patients with unilateral LE not only exhibited substantial reductions in PPT on the affected side compared to the unaffected side (mean difference and 95% confidence intervals: 219 kPa [136.8 to 301.1 kPa] but also when compared to controls (581.1 kPa [340.5 to 821.7 kPa]), showing bilateral pressure-pain hyperalgesia. These differences represented an effect size (ie, standardized mean difference) of 1.23 and .94, respectively. In the same cohort, there were no such deficits in cold and heat pain, cold- and warm-detection thresholds, and vibration-detection thresholds, either between affected and unaffected sides in patients with LE or between patients and controls. Effect sizes for the sensory-detection tests were small, which were generally less than the pain tests. Our data imply that LE is largely characterized by peripheral and central mechanical pain hyperalgesia. PERSPECTIVE This article reveals the presence of bilateral pressure-pain hypersensitivity in patients with unilateral LE. On the contrary, thermal and vibration tests were not significantly different from controls.

Bilateral myofascial trigger points in the forearm muscles in patients with chronic unilateral lateral epicondylalgia: a blinded, controlled study.

ObjectiveThe aim of the present study was to investigate the presence of active and latent muscle trigger points (TrPs) in the forearm musculature on both affected and unaffected sides in patients with lateral epicondylalgia (LE) and healthy controls. MethodsTwenty-five patients with LE and 20 healthy matched controls participated. Both groups were examined for the presence of TrPs in the extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum communis, and brachioradialis muscles in a blinded fashion. TrPs were identified in both affected and unaffected sides within the patient group. In the control group, TrPs were explored around the dominant side. Pressure pain thresholds (PPTs) were assessed on both affected and unaffected arms. ResultsIn the patient group, the number of active muscle TrPs in the affected side was 3.1 [95% confidence interval (CI): 2.8-3.4], whereas in the unaffected arm, only latent TrPs were found (mean: 2.2; 95% CI: 1.8-2.6). Active TrPs were only located on the affected side (P<0.001). Within the control group, the number of latent TrPs in the dominant arm was 0.4 (95% CI: 0.0-0.7), which was significantly lower than the number of latent TrPs in the unaffected arm (P<0.001) in patients. Therefore, latent muscle TrPs in the forearm musculature were associated with the unaffected side in the patient group as compared with the dominant arm in healthy controls: extensor carpi radialis brevis [odds ratio (OR)=66 (95% CI: 9.9-48.8)], extensor carpi radialis longus [OR=16 (95% CI: 3.7-29.6)], brachioradialis [OR=2.6 (95% CI: 0.3-27.1)], and extensor digitorum communis [OR=0.5 (95% CI: 0.4-0.8)]. PPTs were lower around the affected side than around the unaffected arm in patients (mean±SD: 274.5±90.4 KPa vs. 465.4±140.7 KPa; P<0.001) in the patient group. Finally, PPT from the extensor digitorum muscle in those patients with active TrPs (mean±SD: 244±70.4 KPa) was significantly lower (P<0.001) than PPT levels of patients with no TrP in the same muscle (mean±SD: 370±83.4 KPa). ConclusionsLatent TrPs are present in forearm muscles on the unaffected side in patients with LE where active TrPs contribute to the pain on the affected arm. The presence of latent TrPs on the unaffected side in unilateral LE may be related to central sensitization and be a mechanism explaining bilateral pain in some patients with unilateral pathologies.

Examination of Motor and Hypoalgesic Effects of Cervical vs Thoracic Spine Manipulation in Patients With Lateral Epicondylalgia: A Clinical Trial

OBJECTIVES The purpose of this study was to compare the effects of a cervical vs thoracic spine manipulation on pressure pain threshold (PPT) and pain-free grip strength in patients with lateral epicondylalgia (LE). METHODS A single-blind randomized clinical trial was completed with 18 participants with LE. Each subject attended 1 experimental session. Participants were randomized to receive either a cervical or thoracic spine manipulation. Pressure pain threshold over the lateral epicondyle of both elbows pain-free grip strength on the affected arm and maximum grip force on the unaffected side were assessed preintervention and 5 minutes postintervention by an examiner blind to group assignment. A 3-way analysis of variance with time and side as within-subject variable and intervention as between-subject variable was used to evaluate changes in PPT and pain-free grip. RESULTS The analysis of variance detected a significant interaction between group and time (F = 31.7, P < .000) for PPT levels. Post hoc testing revealed that the cervical spine manipulation produced a greater increase of PPT in both sides compared with thoracic spine manipulation (P < .001). For pain-free grip strength, no interaction between group and time (F = .66, P = .42) existed. CONCLUSIONS Cervical spine manipulation produced greater changes in PPT than thoracic spine manipulation in patients with LE. No differences between groups were identified for pain-free grip. Future studies with larger sample sizes are required to further examine the effects of manipulation on mechanisms of pain and motor control in upper extremity conditions.

Radial Nerve Mobilization Decreases Pain Sensitivity and Improves Motor Performance in Patients With Thumb Carpometacarpal Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE To examine the effects of radial nerve mobilization on pain sensitivity and motor performance in subjects with secondary thumb carpometacarpal osteoarthritis. DESIGN Randomized controlled trial. Treatment and placebo were given for 4 weeks. Measurements were taken before intervention, after 1 month (first follow-up), and after 2 months (second follow-up). SETTING Patients from the Department of Physical Therapy, Azienda Sanitaria Locale 3, Collegno (Italy). PARTICIPANTS Participants (N=60; age range, 70-90y) with right-dominant hand secondary thumb carpometacarpal osteoarthritis without other motor-related pathology. All patients completed the study. No patients were withdrawn from the study. INTERVENTIONS Sliding mobilization of the proximal-distal radial nerve or intermittent ultrasound therapy, used as placebo. MAIN OUTCOME MEASURES We hypothesized that radial nerve mobilization induces hypoalgesia and increases strength in secondary thumb carpometacarpal osteoarthritis. We measured pressure pain threshold (PPT) at the trapeziometacarpal joint, the tubercle of the scaphoid bone, and the unciform apophysis of the hamate bone by algometry. Tip pinch strength and tripod pinch strength were measured by a mechanical pinch gauge. RESULTS Treatment increased PPT by 3.33±.24 kg/cm(2) (P<.001) in the trapeziometacarpal joint and was maintained until first follow-up and second follow-up. Also, PPT in the scaphoid bone and hamate bone was increased (P<.001 and P<.02, respectively). Variables in the placebo group remained unchanged. Tip pinch strength increased by 2.22±.22 kg (P<.04) and tripod pinch strength by 2.83±.24 kg (P<.019). CONCLUSIONS Radial nerve mobilization decreases pain sensitivity in the trapeziometacarpal joint and increases tip pinch strength.