Late Cerebellar Atrophy and Long-Term Outcome in Anti-NMDA Receptor Encephalitis (P4.059)

OBJECTIVE: To report the association between late cerebellar atrophy and poor long-term outcome in anti-NMDA receptor (NMDAR) encephalitis. BACKGROUND: We previously reported reversible brain atrophy in anti-NMDAR encephalitis (J Neurol. 2010); however, little attention has been paid to late cerebellar atrophy. DESIGN/METHODS: We reviewed 14 patients (9 females and 5 males, median age 23 years) with anti-NMDAR encephalitis who were admitted to our hospital during 1999 to 2014. Chronological MRI changes in relation to disease severity, complications, treatment, and long-term outcome were evaluated. RESULTS: The initial MRI was unremarkable in 8 patients and showed transient FLAIR hyperintensities in the other 6. Follow-up MRI showed diffuse brain atrophy in 5 patients (36[percnt]) who had severe neurologic deficits, including prolonged unresponsive state, intractable dyskinesias, multiple seizures, recurrent infections, and hypoventilation requiring long ventilation support (ranging 3 to 10 months). Cerebellar atrophy insidiously developed in 2 patients (14[percnt]) along with diffuse brain atrophy. These 2 patients were initially treated with intravenous corticosteroids, immunoglobulins or plasma exchange during the acute stage but did not receive intravenous cyclophosphamide. In 5 patients, ovarian teratoma was found and removed. In 12 patients, including 3 patients with diffuse brain atrophy, the long-term outcome was good (mRS 0-2). In contrast, the two patients with cerebellar atrophy had marked disability (mRS 5) due to severe cerebellar ataxia at the last follow-up (3-4 years after disease onset). While diffuse brain atrophy was reversible, cerebellar atrophy was irreversible and associated with a poor functional outcome. CONCLUSIONS: In anti-NMDAR encephalitis, diffuse brain atrophy can be reversible; thus the presence of brain atrophy does not imply irreversible brain damage. However, cerebellar atrophy is not reversible and may serve as a poor prognostic marker. These findings suggest that the pathophysiology of diffuse brain atrophy and cerebellar atrophy may be different and deserve further investigations. Disclosure: Dr. Iizuka has nothing to disclose. Dr. Someko has nothing to disclose. Dr. Oonuma has nothing to disclose. Dr. Kubo has nothing to disclose. Dr. Nakamura has nothing to disclose. Dr. Ishima has nothing to disclose. Dr. Kaneko has nothing to disclose. Dr. Kitamura has nothing to disclose. Dr. Masuda has nothing to disclose. Dr. Dalmau has received personal compensation in an editorial capacity for Up To Date. Dr. Dalmau has received royalty payments from Athena Diagnostics. Dr. Dalmau has received research support from Euroimmun. Dr. Nishiyama has received research support from Otsuka Pharmaceutical Company, GlaxoSmithKline, Boehringer Mannheim, and Japan Mesiphisicx.