EEG and seizures of pertussis encephalopathy in infants

Objective There are fewer reports on the electroencephalogram(EEG) and seizures of infants with pertussis encephalopathy. Our study retrospectively analyzed the EEG and seizures to raise awareness of pertussis encephalopathy. Methods A total of six cases of infants with pertussis encephalopathy were identified, including 31 consecutive EEG monitoring data sets. Results All infants with pertussis encephalopathy were age of onset ranging from 1 month and 16 days to 3 months and 13 days. Generalized Rhythmic Delta Activity (GRDA) was seen in 5 cases. Multifocal sharp waves and sharp-slow waves were observed in 6 cases, with triphasic sharp waves or sharp-slow waves in the temporal region in 4 cases. Theta rhythms were observed in 4 cases, showing temporal or temporally prominent activity. Four cases exhibited both electroclinical and electrographic seizures(ESzs), while two cases exhibited only electroclinical seizures (ECSzs). Seizure onset involved 3 or more regions in 3 cases, including the frontal, central, parietal, and temporal regions. Seizures were migratory in 4 out of 6 cases. ECSzs included focal clonic, behavioral arrest, and automatism in 2 cases, behavioral arrest in 2 cases, focal clonic in 1 cases, and focal clonic with behavioral arrest in 1 case. Seizures lasting more than 5 min were observed in 5 cases during serial EEG monitoring. When the white blood cell count dropped significantly or approached normal levels, seven or more ECSzs and ESzs were still recorded in 4 cases during four 2–4 h of EEG monitoring. Over a follow-up of 9 months to 2 years 5 months, no seizures recurred. Neurodevelopmental outcomes spanned a spectrum from normal (4 cases) to isolated slightly motor delay (Case 5) to significant global delay (Case 6). Conclusion Infantile pertussis encephalopathy was characterized by ESzs and ECSzs, and notably, the severity of the seizure burden may not correlate with fluctuations in WBC count. These seizures were focal and may have a multifocal or migratory onset, manifesting as focal clonic seizures, behavioral arrest, or automatisms, with some seizures lasting more than 5 min. EEG abnormalities may included GRDA, multifocal (sometimes triphasic) sharp/sharp-slow waves, and theta rhythms that were prominent in the temporal regions. Aggressive treatment may achieve seizure freedom, but long-term neurodevelopmental outcomes remained heterogeneous.