Presenting and residual movement disorders in all-cause autoimmune encephalitis

Movement disorders are among the most common autoimmune encephalitis (AE) symptoms, yet their detailed phenomenology and impact remain underexplored.

We evaluated the prevalence, characteristics, and impact of movement disorders at presentation and latest follow-up in all-cause AE.

We retrospectively reviewed AE patients from a tertiary neuroimmunology clinic. Movement disorders were characterized at presentation and latest follow-up and compared between antibody-positive and antibody-negative disease. Outcomes were assessed using the Modified Rankin Scale (mRS) and the Clinical Assessment Scale in Autoimmune Encephalitis (CASE).

Sixty-eight patients were included (53% female, average age 54 years, SD 20.1, 50% antibody-positive). Thirty-seven (52%) patients had movement disorders at presentation, of whom 23 (34%) had residual movement disorders at latest follow-up. The most common movement disorders at presentation included dystonia, ataxia, stereotypies, and catatonia. The most common residual movement disorders included ataxia, dystonia and parkinsonism. Antibody-negative patients were less likely to present with movement disorders (p = 0.02). Patients with movement disorders at presentation were more likely to be women (p = 0.04), had longer time to first outpatient visit (p = 0.04), and had higher mRS score and CASE Score at presentation (mRS 3.32 vs 2.52, p = 0.015, CASE 6.27 vs 4.39, p = 0.094) and at follow-up (mRS 2.19 vs 1.25, p = 0.017, CASE 2.53 vs 1.28, p = 0.029).

More than half the patients with movement disorders had residual symptoms. Antibody-negative patients were less likely to present with movement disorders. Presence of movement disorders at presentation was associated with poorer overall outcomes.