The Relationship Between Chronic Pain and Cognitive Impairment in the Elderly: A Review of Current Evidence

Abstract

Chronic pain and cognitive impairment are prevalent geriatric syndromes in the population of older adults, and they are the main cause of disability in people over sixty-five years of age. As the global population continues to age, chronic pain and cognitive impairment will affect an increasing number of older adults. While numerous studies in recent years have shown that chronic pain is associated with cognitive decline, the exact mechanisms linking the two remain unclear. In this review, we aim to present the available evidence on the connection between chronic pain and cognitive impairment and to discuss the potential mechanisms by which chronic pain affects cognitive function. In addition, we review potential therapeutic interventions targeting psychological factors, microglia activation, and altered gut flora that may improve and prevent cognitive decline in people with chronic pain.

Keywords:

• chronic pain
• cognitive impairment
• microglia
• psychosocial factors
• gut flora

Abbreviations

Fmri, Functional magnetic resonance imaging; DMN, Default mode network; mPFC, The medial prefrontal cortex; HPA, Hypothalamic-pituitary-adrenal; IL, Interleukin; TNF-α, Tumor necrosis factor-α; iNOS, Inducible nitrous oxide synthase; BBB, Blood-brain barrier; VEGF, Vascular endothelial growth factor; CNS, The central nervous system; CRH, Adrenocorticotropin-releasing hormone; GC, Glucocorticoid; Glu, Glutamate; GABA, Y-aminobutyric acid; LPS, Lipopolysaccharides; SCFAs, Short-chain fatty acids.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, and drawing, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.