Delta brush variant: A novel ictal EEG pattern in anti-NMDAR encephalitis

Challenges to associate early onset epilepsy with COVID-19 autoimmune encephalitis: A case report

BACKGROUND

Diagnosis of coronavirus disease 2019 (COVID-19)-related neurological events in the pediatric population is challenging. Overlapping clinical picture of children with altered neurological state and inborn errors of metabolism, in addition to the frequency of asymptomatic COVID-19 cases, pose the main challenges for diagnosis. Diagnostic approaches to the onset post-COVID 19 subacute encephalopathy are still troublesome as seronegative autoimmune encephalitis (AIE) is reported.

CASE SUMMARY

A 27-mo-old boy was admitted for stormy refractory seizure of polymorphic semiology and altered mental status followed by various neuropsychiatric features that were suggestive of AIE. Brain magnetic resonance imaging and cerebrospinal fluid analysis were normal. Neither the immunological assessment, including viral serologies, antinuclear antibodies, autoimmune antibodies (NMDA, AMPA, CASPR2, LG11, GABARB, Hu, Yo, Ri, CV2, PNMA2, SOX1, Titin, amphiphysin, Recoverin), nor the metabolic assessment for lactate and pyruvate showed significant anomaly. Both positive history of COVID-19 infection and the findings of characteristic repetitive extreme delta brush played a key role in the diagnosis of COVID-19-related AIE. A remarkable improvement in the state of the child was noted after two pulse doses of intravenous Veino-globulin and high dose of intravenous Corticosteroid.

CONCLUSION

Diagnostic biomarkers for AIE might aid effective treatment.

Delta brush on EEG: a characteristic EEG finding in autoimmune encephalitis

A woman in her late 20s was admitted via the emergency department in the psychiatric ward with acute-onset behavioural changes and suicidal thoughts in the past 2 weeks. Workup revealed positive N-methyl-D-aspartate (NMDA) receptor antibodies in cerebrospinal fluid and electroencephalogram (EEG) showing a specific pattern of delta brush on bilateral frontal regions. Other investigations were unremarkable. The patient was started on intravenous methylprednisolone 1000 mg for 5 days with oral steroids. She responded on steroids. She has been recommended for workup for teratoma/mediastinal tumours with NMDA receptor encephalitis is an autoimmune disorder predominantly affecting women of childbearing age. Delta brush pattern on EEG is specific for NMDA receptor encephalitis hence can be used as a diagnostic tool. It is advisable to investigate any patient with the presentation of mental deterioration for pathological causes. However, treatment with immunotherapy increases the chance of survival and may prevent cognitive impairment.