Objective:

We report four cases of NMDA receptor (NMDAR) encephalitis with variable manifestations of catatonia. Despite prolonged illness and associated psychological abnormalities, patients exhibited diverse clinical findings, with catatonia being dominant psychiatric feature.

Background:

Catatonia is well-described, but its recognition is often missed due to unclear clinical understanding, leading to inappropriate treatment. Catatonia typically presents as stupor, mutism, and posturing, with features like waxy flexibility, echophenomena, stereotypy, and cataplexy being pathognomonic. It has been reported in patients with NMDAR encephalitis, where electroconvulsive therapy has shown good clinical response in a case series. However, whether a consistent pattern of catatonic behavior exists in NMDAR encephalitis remains unclear. Whether the manifestations are episodic or associated with epileptogenic EEG activity is undetermined.

Design/Methods:

We reviewed the charts of four patients diagnosed with NMDAR encephalitis who exhibited catatonic features.

Results:

The first case showed altered behavior, forgetfulness of a recently acquired language, intermittent stupor, and frequent echolalia. Patient had no electrographic or clinical seizures despite NMDAR positivity. The second case had catatonia with stupor, staring, and agitation. Patient experienced generalized tonic clonic seizures with left frontal sharp waves. The third case demonstrated episodic catatonia with waxy flexibility, staring, and negativism. EEG revealed right temporal slowing without epileptiform discharges during these episodes. Although the patient experienced religious thoughts in one episode, no EEG correlate was found to suggest Geschwind phenomenon. The fourth case had no behavioral abnormalities but developed focal seizures with secondary generalization, and catatonic features of agitation, negativism, and waxy flexibility.

Conclusions:

Recognizing catatonia in NMDAR encephalitis is crucial, as it may present independently of seizures with or without behavioral disturbances. In our cohort, catatonia appeared as an isolated predominant psychiatric feature with or without seizures. Two patients exhibited catatonia and behavioral changes without seizures. Therapeutic strategies would change if episodes were deemed catatonic rather than epileptic.