Characteristics and prognostic factors of cognitive impairment in autoimmune glial fibrillary acidic protein astrocytopathy.

BACKGROUND: Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) is a condition that can occasionally cause cognitive impairment (CI). This study aimed to clarify the characteristics of CI in patients with GFAP-A expression and its associated prognostic factors. METHODS: This retrospective cohort study included patients diagnosed with GFAP-A at Gifu University, Japan. The prevalence and types of CI and the course of their development was investigated. Furthermore, the odds ratio (OR) of the associated factors of concomitant CI and prognostic factors of persistent CI were investigated using binary logistic regression. RESULTS: CI was observed in 120 of the 291 patients (41.2%). The types of CI varied, and the initial symptoms were rarely CI. Factors associated with the development of CI were age (OR 1.03, 95% CI 1.01-1.05, p=0.02) and lymphocyte count in cerebrospinal fluid (OR 0.99, 95% CI 0.98-0.999, p<0.01). 37 of 198 patients (18.6%) had cognitive impairment at the last follow-up (≥ 6 months). Factors associated with CI at the final follow-up were age (OR 1.07, 95% CI 1.03-1.11, p<0.01) and the interval from onset to treatment initiation (OR 1.01, 95% CI 1.002-1.01, p=0.013). The modified Rankin Scale score at 6 months after treatment (OR 2.102, 95% CI 1.404-3.380, p<0.01) was associated with the transition of CI to sequelae. CONCLUSION: 41.2% of patients with GFAP-A developed CI, with 18.6% having persistent deficits at the last follow-up. Older age and delayed treatment were risk factors, and the affected patients showed less acute inflammation.