Acute-phase electroencephalography for an infantile atypical teratoid/rhabdoid tumor

Background: Primary brain tumor is a leading cause of death in cancer-bearing children. Acutely progressive patterns of electroencephalography (EEG) remain to be investigated for children with rapidly growing brain tumors. Case report: A 14-month-old boy was transferred to our department for prolonged seizures and unrecovered consciousness on his fifth day of illness. The EEG recording on admission showed highly disorganized background activity with high-voltage rhythmic delta waves. Serial EEG monitoring revealed a rapid transition of the background activity to the suppression-burst pattern, and then to generalized suppression of cortical activity within a few hours after admission. Magnetic resonance imaging detected a midline tumor at the pineal gland extending to the midbrain and pons. The tumor was pathologically confirmed as atypical teratoid/rhabdoid tumor (AT/RT) with absent expression of SMARCB1. He died of tumor progression on the 20th day after admission. Conclusion: AT/RT is an additional category of brain tumors that cause the clinically and electro-physiologically critical condition in a few days after the onset.