Cognitive and Patient‐Reported Outcome Measures in LGI‐1‐IgG Autoimmune Encephalitis

OBJECTIVE: Clinical outcome measures for autoimmune encephalitis (AE) are not yet well defined. Cognitive outcome measures (CogOs) and patient-reported outcomes (PROs) may capture the symptoms of AE, beyond clinician-reported outcomes (ClinROs) (the Modified Rankin Scale mRS and Clinical Assessment Scale in Autoimmune Encephalitis CASE). METHODS: This retrospective cohort study examined LGI-1-IgG AE patients at Cleveland Clinic. CogOs included the Rey Auditory Verbal Learning Test (RAVLT) and Brief Visuospatial Memory Test (BVMT). PROs included Neuro-QoL, PROMIS Global Physical (GPH) and Mental Health (GMH). Abnormal RAVLT, BVMT (≤ -1.5 SD), Neuro-QoL, and PROMIS (≥ 10 T-scores) proportions were analyzed. CogOs and PROs were correlated with ClinROs using Spearman's rank correlation. RESULTS: Forty-four patients (64% male, mean age 68 SD = 11, median follow-up 19 months) were included. ClinROs improved, with median mRS decreasing from 2.5 (IQR = 2-3) to 2 (IQR = 1-2), and CASE from 5 (IQR = 3-6) to 3 (IQR = 2-3) (all p 12 months from diagnosis, cognition was impaired on BVMT (56%) and RAVLT (20%). PROs showed impairments in Neuro-QoL lower (38%) and upper (27%) extremity function, cognition (31%), and PROMIS-GPH (25%). RAVLT correlated with Neuro-QoL cognition, depression, and stigma, while BVMT correlated with PROMIS-GMH (all unadjusted p < 0.05). Neither RAVLT nor BVMT correlated with ClinROs. ClinROs correlated with Neuro-QoL lower extremity function, cognition, and social roles (all p < 0.05). INTERPRETATION: LGI-1-IgG AE patients have long-term impairments in cognition, physical health, and social roles, which can be objectively measured using CogOs and PROs and are not captured by ClinROs.