An Uncommon Overlap Syndrome Between Ankylosing Spondylitis and Amyotrophic Lateral Sclerosis—Case Report

This case report describes an uncommon overlap syndrome between ankylosing spondylitis (AS) and amyotrophic lateral sclerosis (ALS). Initially, the patient was diagnosed with AS, for which he received various specific treatments, including TNF-α inhibitors. After five years of treatment with TNF-α inhibitor etanercept, the patient was referred for a full neurological assessment after he reported balance disturbances, postural instability, muscle weakness, and other neurological symptoms that indicated the presence of a neurological disorder. After a thorough investigation, the patient was diagnosed with ALS. This case report aims to contribute to the limited literature by providing a detailed case study regarding the crosstalk between AS and ALS while also exploring the potential underlying mechanisms and the possible link between TNF-α inhibitors therapy and ALS.