Case Presentation: Autoimmune encephalitides comprise a rapidly evolving group of immune-mediated disorders characterized by inflammation of the brain parenchyma. Patients with this disorder manifest a wide spectrum of neurological and psychiatric presentations developing over days to months. One sub-type is anti-NMDAR-encephalitis, which is characterized by complex neuropsychiatric features and the presence of IgG antibodies against the NR1 subunit of the NMDA receptors in the CNS. We present an unusual case of anti-NMDAR-encephalitis that involved repetitive focal seizures with profound speech apraxia.An 18-year-old female presented to our ED with increasingly unusual spells and a loss of ability to speak. Three months prior, patient had her first seizure with loss of consciousness. Three weeks earlier, she developed spells of involuntary mouth opening and forced vocalization lasting 10-20 seconds. Three days earlier she had lost her ability to speak. Her family noted decreased appetite and episodes of agitation. 10-days earlier she was admitted to another institution where video EEG monitoring was negative for epileptiform discharges with a final diagnosis of psychogenic nonepileptic attacks. In our emergency department, she was witnessed to have numerous spells of slow mouth opening associated with forced nonverbal vocalization and subtle facial twitching. On exam, she could not vocalize words yet her comprehension and ability to express herself with writing were preserved. The neurology team suspected anti-NMDAR-encephalitis. She was started on high-dose methylprednisolone and IV levetiracetam. Brain MRI showed multiple cortical areas of restricted diffusion involving especially frontal premotor cortices and insula. Video EEG captured many of her clinical events that were not associated with epileptiform discharges. Asymmetric slow activity was noted in the temporal regions. Lacosamide was added on the second day with complete cessation of seizures. A lumbar puncture was performed with CSF analysis showing an elevated WBC count of 15 and positive CSF oligoclonal bands. Despite seizure control, she continued to have significant speech apraxia and recurrent episodes of agitation. She developed subtle orofacial dyskinesia and transient fever. IVIG was initiated with a good response and gradual improvement of speech and behavior. After 2 weeks the patient was discharged home with outpatient follow-up with a neuroimmunologist. One week later, her autoimmune encephalitis panel in the serum and CSF were both positive for NMDA-receptor antibodies.
Discussion: Due to its wide spectrum of neuropsychiatric symptoms, anti-NMDAR-encephalitis is difficult to accurately diagnose and treat. In our case, the patient’s seizure and speech apraxia were atypical, which led to the initial misdiagnosis of psychogenic nonepileptic attacks. Anti-NMDAR-encephalitis should be suspected in patients who present with new-onset seizures and rapidly progressive cognitive decline. Though antibodies against NMDA-receptor would help confirm the diagnosis, results can take several weeks. If left untreated, patients can have severe, progressive neurologic deterioration and possibly death. Patients with suspected anti-NMDAR-encephalitis should immediately start therapy based on clinical presentation.
Conclusions: In conclusion, patients with anti-NMDAR-encephalitis require early recognition and prompt treatment, even prior to confirmatory laboratory results, to result in excellent outcomes.