Insomnia is associated with symptoms of central sensitization in patients with painful temporomandibular disorders.

BACKGROUND: Central sensitization (CS) and temporomandibular disorder (TMD) are both associated with insomnia. Therefore, the authors aimed to investigate whether insomnia was associated with more symptoms of CS in patients with TMD. METHODS: In 82 volunteers with TMD, insomnia was clinically assessed, allowing sample stratification according to its presence. The Central Sensitization Inventory questionnaire was self-applied to assess the clinical symptoms of CS. RESULTS: Participants with insomnia had significantly higher mean (SD) scores of CS according to the Central Sensitization Inventory than participants without insomnia (43.10 [12.57] vs 26.59 [13.66]; P = < .001). CONCLUSIONS: Insomnia was associated with higher scores of CS symptoms in patients with TMD. PRACTICAL IMPLICATIONS: Insomnia influences TMD as well as its relationship with CS, and, therefore, it is critical to the clinical management of TMD.

Are central sensitization symptoms and psychosocial alterations interfering in the association between painful TMD, migraine, and headache attributed to TMD?

OBJECTIVE: To determine if somatosensory function and symptoms related to central sensitization (CS) differed in individuals with painful temporomandibular disorders (TMD) according to the presence of migraine (MIG) or MIG + headache attributed to TMD (HAT). MATERIALS AND METHODS: This study evaluated 92 adults (20-65 years), presenting painful TMD. Standard diagnostic criteria were applied to classification of painful TMD, MIG, and HAT. CS was assessed through the central sensitization inventory (CSI), wind-up ratio (WUR), pressure pain thresholds (PPT), and the conditioned pain modulation test (CPM). Psychosocial factors were evaluated by validated instruments. RESULTS: There was a significant difference regarding gender, with more women in the group TMD + MIG + HAT (p = 0.028). TMD + MIG and TMD + MIG + HAT had significantly lower PPTs than the TMD group. No group differences were found for the WUR, CPM, or CSI. TMD + MIG + HAT had higher chronic pain intensity (p = 0.001), disability points (p = 0.045), graded chronic pain scale (p = 0.007), and higher somatization (NSPS) scores (p = 0.012), compared to the other groups. CONCLUSION: Mechanical hyperalgesia was more pronounced in the group with the highest pain and somatization scores, while CPM and WUR did not differ between groups. Altered somatosensory function and CS may partially underlie the pathophysiology of overlapping TMD pain conditions, pointing towards additive effects of comorbid head pains. CLINICAL RELEVANCE: Our results demonstrate the importance of considering the association of primary and secondary headaches during TMD assessment and its implications for maintaining the signs and symptoms of CS. This can influence the conduct of treatment, which must be multidisciplinary, and must include management of mechanisms related to CS.

Lack of correlation between central sensitization inventory and psychophysical measures of central sensitization in individuals with painful temporomandibular disorder.

OBJECTIVE: To assess the correlation between the Central Sensitization Inventory (CSI) scores and the results of psychophysical tests and psychosocial questionnaires according to the presence of painful temporomandibular disorder (TMD). DESIGN: It was a cross-sectional study involving 146 participants, aged 20-65 years. Painful TMD was classified using the Research Diagnostic Criteria for Temporomandibular Disorders. CSI was applied to assess "central sensitization-related symptoms", as has been suggested. Wind-up ratio, pressure pain threshold and conditioned pain modulation were used as psychophysical tests to evaluate signs and symptoms of central sensitization. Psychosocial factors were assessed by the presence of non-specific physical symptoms, depressive and anxiety symptoms. The sample was divided into two groups: Control (n = 31); Painful TMD (n = 115). Descriptive statistics characterized the sample. Correlation analysis were performed using Pearson's and Spearman's correlation coefficients (α = 5%). RESULTS: Of the total sample, 78.8 % presented painful TMD, and the mean (standard deviation) age was 37.4 (±11.5) years. Anxiety symptoms (p = 0.028) and non-specific physical symptoms (p < 0.001) were more frequent in the painful TMD group than in controls. Painful TMD patients presented higher scores of the CSI (p < 0.001) and lower pressure pain thresholds (p ≤ 0.020) compared to controls. CSI scores were significantly correlated with psychosocial measures (p < 0.001) but not with psychophysical tests (p ≥ 0.089). CONCLUSION: The CSI scores did not correlate with psychophysical measures of central sensitization but were positively correlated with the results of psychosocial questionnaires.