Objective:

Describe the utility of neuroimaging and EEG in children who present to a pediatric emergency department (PED) with altered mental status (AMS).

Background:

The differential diagnosis of AMS is wide and ancillary testing is often required to make a definitive diagnosis. The utility of neuroimaging and EEG has not been well studied in AMS.

Design/Methods:

A retrospective chart review of children aged 0-18 years who presented to a PED from 1/1/2018 to 12/31/2021 with AMS. We abstracted patient demographics, presence of comorbidities, laboratory and imaging data, disposition from the PED, and final diagnosis. Neuroimaging (CT and MRI) studies and EEG were classified as normal or abnormal. Abnormal results were further categorized as contributory to the current diagnosis, clinically important but not contributory to the current diagnosis, and incidental. 

Results:

We analyzed the charts of 371 patients. The most common etiology of AMS was accidental ingestion (188, 51%). Structural/anatomical neurologic conditions, and seizures as potential etiology were noted in one-tenth (51;13.8%). A conclusive diagnosis could not be reached in 58 patients (16%).   

Neuroimaging was performed in 159 (43%). The most common was CT (150, 40%) followed by MRI (18, 5%) and 10 patients had both. The breakdown of neuroimaging abnormalities was as follows: contributed to the final diagnosis 18 (4.8%), clinically important but did not contribute to the diagnosis 22 (5.9%), and incidental findings 3 (0.8%). EEG was performed in 65 patients (17.5%) of which 23% had findings that contributed to the final diagnosis.

Conclusions:

Neuroimaging contributed to a definitive diagnosis in a minority of patients, whereas EEG contributed to diagnosis in about one fourth of the patients. Further studies are required to identify subsets of children with AMS who will benefit from directed neurological investigations.