Chances and limitations of point of care EEG in the assessment of children with unclear altered mental status in the emergency department

Introduction: Rapid diagnosis and treatment are essential in children with altered mental status (ASM). The most important neurological causes are encephalitis and non-convulsive status epilepticus (NCSE). The EEG is an essential part of the diagnosis. A standard EEG (sEEG) poses logistical problems and is time-consuming. A point of care EEG with two channels (poc-EEG) is easy to install in the emergency department, but there is little literature on its feasibility and benefits. We present the preliminary results of a retrospective and prospective study.

Aim: To test the feasibility and utility of poc-EEG in differentiating NCSE from other causes in children with ASM in the emergency department.

Patients and methods: We recruit all children presenting to the emergency department with unclear ASM. We document the symptoms, the time interval between arrival in the emergency department and installation of the poc-EEG, the bedside poc-EEG findings in the emergency department, the poc-EEG findings by the neuropediatrician on duty on the phone, additional diagnostics performed and the final diagnosis. Case examples are presented.

Results: So far, 30 children have been recruited (20 retrospectively and 10 prospectively). The pocEEG could be installed in 14/30 within a maximum of 20 minutes. The pocEEG was unremarkable in 11/30 cases; 17/30 showed rhythmic spike waves and 2/30 showed focal changes. The final diagnoses were: postictal state (n=7), NCSE (n=17), shunt dysfunction (n=1), encephalitis (n=1), psychogenic (n=1), disturbance of consciousness in hypoglycemia (n=1) and unclear (DD psychogenic, DD confusional migraine) (n=2). In the prospective part (n=10), the emergency physician found the pocEEG helpful for diagnosis and therapy in 9/10 of the cases. The poc-EEG findings of the emergency physician and the neuropaediatrician agreed in 6/10 of the cases.

Conclusion: The pocEEG can be installed quickly and easily. It can help to detect NCSE in children with an unclear ASM and indirectly indicate the presence of encephalitis.