Disease progression and brain atrophy in NMDAR encephalitis: Associated factor & clinical implication

Area of Science:

• Neurology
• Neuroimmunology
• Neuroradiology

Background:

• N-methyl d-aspartate receptor-antibody (NMDAR) encephalitis is a severe autoimmune neurological disorder.
• Brain volume changes, particularly in the cerebellum, are increasingly recognized in NMDAR encephalitis.
• Understanding the longitudinal patterns and clinical implications of these changes is crucial for patient management.

Purpose of the Study:

• To investigate the longitudinal pattern of brain volume changes in NMDAR encephalitis.
• To identify factors determining these brain volume changes.
• To explore the clinical implications of cerebellar volume reduction in NMDAR encephalitis.

Main Methods:

• Serial MRI scans were used to measure normalized brain region volumes in 36 NMDAR encephalitis patients over a median follow-up of 28.5 months.
• Clinical data, including the Clinical Assessment Scale in Autoimmune Encephalitis (CASE) and modified Rankin scale (mRS), were collected.
• Cumulative disease burden and duration of status epilepticus were evaluated at each MRI time point.

Main Results:

• The cerebellum showed the most significant volume reduction (94.4% of baseline volume at last MRI, p < 0.001).
• Cerebellar volume reduction followed a progressive course for up to 2 years post-disease onset.
• Reduced cerebellar volume correlated positively with mRS, total CASE scores, and specific functional deficits (memory, language, psychiatric, gait, weakness), and was associated with cumulative disease burden, status epilepticus duration, and delayed teratoma removal.

Conclusions:

• Cerebellar volume reduction in NMDAR encephalitis is a progressive process once initiated.
• The degree of cerebellar atrophy reflects the cumulative disease burden and extent of disease progression.
• Cerebellar volume reduction is associated with poorer outcomes across multiple functional domains.