Neuropathic Pain in Critical Covid-19 illness Survivors: A Narrative Review

Abstract

Introduction: The COVID-19 pandemic has resulted in a significant number of cases worldwide, leading to a substantial increase in Intensive care unit (ICU) admissions. Survivors of critical illness are known to experience long-term physical, cognitive, and psychological impairments. Chronic pain is also a prevalent complication, and specifically, neuropathic pain (NP) is strongly linked to a diminished quality of life. This narrative review aims to investigate the incidence, causes and manifestations of NP in critical illness COVID survivors. Methods: A comprehensive search of the Pubmed database was conducted on May 31, 2023, using the keywords "Covid-19" OR "Sars-cov-2" combined with "neuropathic pain" and "critical care" OR "intensive care unit" to identify relevant publications in English or Spanish pertaining to adult human subjects. The search process adhered to the recommended flowchart format outlined in the PRISMA 2020 statement. Results: The primary search yielded 26 results. Eight results were excluded as they did not pertain to COVID-19 pain. Discussion: Intensive care survivors can develop new onset pain and chronic pain though various mechanisms. In the case of critical illness COVID-19 survivors, pain may arise due to viral neurotropic potential, immune-mediated reactions, and microvascular complications. Studies have reported new-onset upper extremity NP, with ulnar neuropathy being the most prevalent, followed by brachial plexus, axillary, and median neuropathies. Lower limb NP particularly sciatic neuropathy has also been documented, along with peroneal nerve, meralgia paresthetica, and femoral neuropathy. Cranial neuropathies, such as facial palsy and trigeminal neuralgia, have been observed in case series. Additionally, widespread pain frequently associated with critical illness neuromyopathy may be present. Notably, COVID-19 survivors with critical illness may experience nociplastic pain and conditions related to central sensitization, posing challenges in distinguishing them from those with Long-COVID syndrome. Conclusion: Further research is crucial to gain a comprehensive understanding of the neurological consequences arising from critical COVID-19 illness. Healthcare professionals should maintain a high suspicion index for NP in this population. Advancing our knowledge of NP in COVID-19 survivors can help develop effective strategies to enhance overall patient outcomes.