Can high pain intensity and catastrophizing interfere with the cognitive performance of women with chronic pain related TMD? A cross-sectional study

Abstract Interventions based on pain education and self-management are dependent on factors such as attention, memory, concentration, and executive function. Objective To explore the relationship between cognitive performance and the variables pain intensity, central sensitization, catastrophizing, and hypervigilance in women diagnosed with chronic pain-related TMD. Methodology This is a cross-sectional study. A total of 33 women (mean age: 38±4.6 years; range: 18 to 66 years) with chronic pain-related TMD (myalgia and/or arthralgia) diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Specific questionnaires were used to evaluate cognitive performance, overall pain intensity, central sensitization, hypervigilance, and pain catastrophizing. The data were analyzed using Pearson’s correlation coefficient and backward stepwise multiple linear regression (statistical significance at 5% alpha). Results Approximately 53% of the study sample showed decreased cognitive performance. High central sensitization, hypervigilance, and pain catastrophizing were observed. A significant negative correlation was observed between cognitive performance and hypervigilance (p=.003, r=−.49), cognitive performance and catastrophizing (p<.001, r=−.58), and cognitive performance and pain intensity (p<.001, r=−.58). Regarding the partial regression coefficients, only catastrophizing and pain intensity showed statistical significance (t=−2.12, p=.043; t=−2.64, p=.014, respectively), indicating a significant role in explaining cognitive performance at the sample. Conclusion High pain intensity and the presence of catastrophic thoughts regarding pain can predict impaired cognitive performance in women with chronic pain-related TMD. Management strategies addressing psychosocial dimensions such as reducing catastrophizing and ensuring complete understanding of the condition are important.


Introduction
The high prevalence of chronic pain and the therapeutic difficulties associated with its management makes it a serious public health problem 1,2 with considerable social, familiar, emotional, and cognitive impacts. Therefore, the management of chronic pain must go beyond the individual experience to include a wider approach that takes nociception and other bio-psychosocial aspects into consideration. 3 Both in Brazil and worldwide, chronic pain is more commonly observed in women, and its prevalence rates range from 29% to 73%, 4  Patients with chronic pain typically exhibit impaired outcomes in tests examining cognitive performance and self-perception of their condition in social situations and daily activities. [7][8][9] Previous observational clinical studies found that most patients with chronic pain report loss of memory and concentration, particularly during severe episodes. 8,10,11 Other studies showed that activities related to the executive function may also be mild to moderately impaired in these patients, leading to higher levels of distraction and reduced cognitive abilities. 1, 12,13 The literature also shows the significant role of memory in the relationship between chronic pain and cognitive performance, particularly in older patients, although the specific type of memory (working memory, short and/or long-term memory, or autobiographical memory) involved is still unclear. 1,14 The experience of pain also includes various emotional and behavioral aspects, such as catastrophizing and hypervigilance, which can influence pain modulation and hinder effective management. 15,16 Therefore, this study aimed to explore the relationship between the variables pain intensity, central sensitization, catastrophizing, and hypervigilance with cognitive performance in women diagnosed with chronic pain-related TMD (myalgia and/or arthralgia) to elucidate the influence of those variables on the cognitive performance and to contribute to the development of appropriate strategies that consider these parameters. The hypothesis is that cognitive performance is influenced by these predictor variables.

Statistical analyses
The post-study power test was used to calculate the scope power of the study using the website clincalc. I n a c c o r d a n c e w i t h t h e D C / T M D , 1 7 , 1 8 temporomandibular joint disorders were classified into 12 categories, as follows: local myalgia (7), myofascial pain (7), referred myofascial pain (15), arthralgia (26), TMD attributed headache (14), disc displacement with reduction (11), disc displacement with reduction with intermittent locking (1), degenerative disease (5), and subluxation (1). The duration of pain ranged from 6 to 420 months (mean duration: 80.24±85 months).
After the TMD diagnosis, the sample was distributed in pain-related TMD clusters, as follows: four subjects with arthralgia, seven subjects with myalgia, and 22 subjects with arthralgia and myalgia associated. Table   1 shows descriptive data (mean, standard deviation) by cluster and an analysis of variation (ANOVA 1 criterion) between them for each variable studied.
The results showed no significant differences between clusters (p>.05).    Incomplete high school 2 <12 Complete high school 11 12 Incomplete higher education 6 >12 Complete higher education 4 >12 Note: own elaboration.       Some confounding variables such as the continuous use of medications (antidepressants, anticonvulsants, and muscle relaxants), presence of comorbidities, and specific symptoms related to anxiety and depression, may also influence outcomes. Thus, mental health disorders, which are frequently observed in patients with pain-related TMD and chronic pain, also play a role in impaired cognitive performance, caused by medications use or by the chronic pain condition. 13,32 However, some studies have also shown that patients with chronic severe pain exhibit impaired basic neurocognitive functions, regardless of the presence of depressive symptoms and medication use. 35 The relationship between chronic pain and cognitive performance can affect patient's daily activities, including those related to attention, memory, and Therefore, the findings of this study, as well as with previous evidence, 22,23 highlight the importance of evaluating cognitive impairment in patients with chronic pain-related TMD, based on the understanding that the neural pathways common to these two experiences are focused on pain processing and, therefore, may also impair cognition. Pain catastrophizing and higher pain intensity levels can predict the appearance of cognitive deficits in patients with chronic pain-related TMD and, upon identification of this triad (catastrophizing, high pain level, and impaired cognitive performance), professionals should design strategies that first aim to reduce catastrophic thoughts and ensure complete understanding of the condition of chronic pain and, later, focus on changing behaviors and identifying worsening, predisposing, and/or perpetuating factors to promote pain education. 13,22,23,27,30 Study limitations This was a cross-sectional study that aimed to track relationships between painful and psychological TMD variables and cognitive performance. It was conducted in the dental clinic during the undergraduate students' academic year; thus, the possibilities of rigorous control for a robust study were limited. Future studies should present larger samples, include a control group, observing and controlling other present body pains, as well as considering the duration of pain as a predictor of the analyzed variables to obtain results that can be scientifically extrapolated.

Conclusion
The results show that the high intensity of pain and the presence of catastrophizing can predict impaired cognitive performance in women with chronic painrelated TMD, and with the mental dimensions of memory, attention, and executive/visuospatial function being compromised; therefore, proving to be an important topic to more robust scientific investigations.
Cognitive deficit can influence the patient's response Can high pain intensity and catastrophizing interfere with the cognitive performance of women with chronic pain related TMD? A cross-sectional study 2023;31:e20220384 9/10 to pain education strategies, which depend on the understanding of the condition and actions aimed at behavioral changes. Therefore, patients' refractory to this type of approach may present a cognitive performance lower than expected because of chronic pain experience, and do not respond to pain education, since aspects such as memory and attention are compromised. Therefore, alternative pain education strategies should be identified, delivered objectively, and reinforced frequently in patients with chronic painrelated TMD exhibiting catastrophizing and high pain intensity. Strategies aimed at psychosocial dimensions such as changes in exaggerated negative mental habits should also be included in this process.