Ear abnormalities in chronic fatigue syndrome (CFS), fibromyalgia (FM), Coronavirus-19 infectious disease (COVID) and long-COVID syndrome (PCS), sick-building syndrome (SBS), post-orthostatic tachycardia syndrome (PoTS), and autoimmune/inflammatory syndrome induced by adjuvants (ASIA): A systematic review

Chronic fatigue syndrome (CFS), fibromyalgia (FM), silicone breast implants (SBI), Coronavirus-19 infectious disease (COVID), COVID-19 vaccination (post-COVIDvac-syndrome), Long-COVID syndrome (PCS), sick-building syndrome (SBS), post-orthostatic tachycardia syndrome (PoTS), and autoimmune/ inflammatory syndrome induced by adjuvants (ASIA) are a cluster of poorly understood medical conditions that have in common a group of ill-defined symptoms and dysautonomic features. Most of the clinical findings of this group of diseases are unspecific, such as fatigue, diffuse pain, cognitive impairment, paresthesia, tachycardia, anxiety, and depression. Hearing disturbances and vertigo have also been described in this context, the underlying pathophysiologic process for these conditions might rely on autonomic autoimmune dysbalance. The authors procced a literature review regarding to hearing and labyrinthic disturbances in CSF, FM, SBI, COVID, post-COVIDvac-syndrome, PCS, SBS, POTS, and ASIA. The PRISMA guidelines were followed, and the literature reviewed encompassed papers from January 1990 to January 2024. After the initial evaluation of the articles found in the search through Pubmed, Scielo and Embase, a total of 172 articles were read and included in this review. The prevalence of hearing loss, dizziness, vertigo and tinnitus was described and correlated with the diseases investigated in this study. There are great variability in the frequencies of symptoms found, but cochlear complaints are the most frequent in most studies. Vestibular symptoms are less reported. The main pathophysiological mechanisms are discussed. Direct effects of the virus in the inner ear or nervous pathways, impaired vascular perfusion, cross-reaction or autoimmune immunoreactivity, oxidative stress, DNA methylation, epigenetic modifications and gene activation were implicated in the generation of the investigated symptoms. In clinical practice, all patients with these autoimmune conditions who have any audiological complaint an ENT consultation followed by an audiometry are needed.