Early progression of brain atrophy in patients with anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis responds to immunnotherapy, and approximately 80% of patients with this disorder fully recover or have only minor sequelae. Brain magnetic resonance imaging (MRI) does not show a specific abnormality, but some patients have progressive cerebral atrophy. The cerebral atrophy can become reversible after clinical improvement. METHODS We describe 3 patients with diffuse cerebral atrophy (DCA) on serial brain MRI. RESULTS Two women had the typical spectrum of this disorder, and one man had mainly psychiatric symptoms. In a woman with an ovarian tumor, DCA was reversible and DCA developed within about a half month. In another woman without a tumor, DCA was evident within 19 days and had progressed over the course of 4 years. The titers of anti-NMDAR antibodies in serum and cerebrospinal fluid (CSF) initially decreased, and low titers of the antibodies persisted. In a man without a tumor, DCA progressed within 14 days, and during this short period, he did not receive prolonged treatment with corticosteroids, various antiepileptic agents, or propofol, and he was free of seizures and ventilatory support. CONCLUSION Not only a woman but also a man with anti-NMDAR encephalitis can have DCA in the early phase of this disorder. However, DCA can be reversible after clinical improvements. The early progression of DCA is not necessarily a poor prognostic factor.