Evidence for Cognitive Decline in Chronic Pain: A Systematic Review and Meta-Analysis

Abstract

Background: People with chronic pain (CP) sometimes report impaired cognitive function, including a deficit of attention, memory, executive planning, and information processing. However, the association between CP and cognitive decline was still not clear. Our study aimed to assess the association of CP as a risk factor with cognitive decline among adults.Methods: We included data from clinical studies. Publications were identified using a systematic search strategy from PubMed, Embase, and Cochrane Library databases from inception to October 10, 2020. We used the mean cognitive outcome data and the standard deviations from each group. The standardized mean difference (SMD) or odds ratio (OR), and 95% confidence intervals (CI) were performed for each cognitive decline outcome. I2-values were assessed to quantify the heterogeneities.Results: We included 37 studies with a total of 52,373 patients with CP and 80,434 healthy control participants. Because these studies used different evaluative methods, we analyzed these studies. The results showed CP was associated with cognitive decline when the short-form 36 health survey questionnaire (SF-36) mental component summary (SMD = −1.50, 95% CI = −2.19 to −0.81), the Montreal cognitive assessment (SMD = −1.11, 95% CI = −1.60 to −0.61), performance validity testing (SMD = 3.05, 95% CI = 1.74 to 4.37), or operation span (SMD = −1.83, 95% CI = −2.98 to −0.68) were used. However, we got opposite results when the studies using International Classification of Diseases and Related Health Problems classification (OR = 1.58, 95% CI = 0.97 to 2.56), the Mini-Mental State Examination (SMD = −0.42, 95% CI = −0.94 to 0.10; OR = 1.14, 95% CI = 0.91 to 1.42), and Repeatable Battery for the Assessment of Neuropsychological Status memory component (SMD = −0.06, 95% CI = −0.37 to 0.25).Conclusion: There may be an association between CP and the incidence of cognitive decline when some cognitive, evaluative methods were used, such as short-form 36 health survey questionnaire, Montreal cognitive assessment, performance validity testing, and operation span.

Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre

“…1A), as memory impairment, foggy brain and problems with attention, are recognized consequences of depressive and/or anxious states 37 and chronic pain. 38 The impact of baseline characteristics, including age and CFS, and the persistence of long-COVID-19 on HR-QoL, was also investigated. Righi et al 21 reported that a status of excellent physical health, present in 90% of patients prior to SARS-CoV-2 infection declined to 24% at disease onset and then increased to 82% at nine-months of follow-up.…”

Association of Chronic Pain with Biomarkers of Neurodegeneration, Microglial Activation, and Inflammation in Cerebrospinal Fluid and Impaired Cognitive Function

“…These results are in line with two recent meta-analyses, which failed to show a clear association between chronic pain and cognitive decline and advocated for further investigations. 5,6 Our findings are strengthened in that we adjusted for important confounders known to influence cognitive function, such as APOE ε4 carrier status, depressive symptoms, and intake of analgesics. 47 Moreover, our outcomes consisted of composite scores of memory and executive function, validated in ADNI, a well-established cohort specifically designed to investigate questions pertaining to AD.…”

“…Large longitudinal studies suggest that chronic pain is associated with cognitive decline and incident dementia 3,4 . However, two recent systematic reviews and meta‐analyses failed to show an unequivocal link between the two conditions, highlighting the heterogeneity among the included studies in terms of pain definition and assessment, follow‐up time, neuropsychological testing, and definitions of cognitive decline and dementia 5,6 . Furthermore, analyses were not always adjusted for risk factors known to alter cognitive function such as analgesic intake and depression, highly prevalent in chronic pain 7 .…”

Cognitive function in individuals with and without painful and painless diabetic polyneuropathy—A cross‐sectional study in type 1 diabetes

“…11 Another factor associated with cognitive impairment is chronic pain conditions, where problems with concentration, memory, processing and attention are prevalent. 12,13 A common cause of chronic pain is peripheral neuropathic pain, a condition that has shown changes in the neural pathways involved in cognition. 9,14 Peripheral neuropathic pain is experienced by 15-25% of individuals with diabetes and DPN in their lower extremities and is known as painful DPN.…”