Development of carpal tunnel syndrome in association with checkpoint inhibitors.

Introduction: The incidence of neuropathy with checkpoint inhibitors is 0.3-1%, typically occurring 2-12 weeks after treatment initiation. Common neuropathy phenotypes include inflammatory myopathies, myasthenia gravis, acute and chronic demyelinating polyradiculopathies, vasculitic neuropathies, isolated cranial neuropathies, aseptic meningitis, autoimmune encephalitis, multiple sclerosis and hypophysitis. Carpal tunnel syndrome is the most common entrapment neuropathy in the general population; however, the association of carpal tunnel syndrome with checkpoint inhibitors is exceedingly rare.

Case Report: We report two cases of patients with no prior history of carpal tunnel syndrome treated with checkpoint inhibitors that developed de novo bilateral carpal tunnel syndrome. For both patients, the neurologic symptoms improved with cessation of the checkpoint inhibitor and initiation of corticosteroids.

Discussion: Given the prevalence of carpal tunnel syndrome in the general population, a high index of suspicion for carpal tunnel in patients receiving checkpoint inhibitors and prompt treatment with corticosteroids is essential.