Pain linked to anti-CASPR2 antibodies

Autoantibodies to contactin-associated protein 2 (anti-CASPR2) cause pain and limbic autoimmune encephalitis. In this study, German researchers analyzed clinical pain data from a large cohort of patients investigating autoimmune encephalitis. Of the 102 patients in the cohort, 36% described frequent pain, 63.6% severe pain and 55.6% pain as their major symptom. Pain phenotypes varied from patient to patient, but the analyses identified two major phenotypes: symmetrical distal burning pain and generalized pain with myalgia and cramps. Certain pre-existing risk factors for chronic pain (diabetes mellitus, peripheral neuropathy, chronic back pain) reinforced the pain picture.