To describe the impact of non-diagnostic head CT in the evaluation of acute childhood stroke.

Diagnosis of childhood arterial ischemic stroke is often delayed.  Head MRI is recommended to evaluate the stable child with acute neurologic deficit due to the high frequency of stroke mimics.  However, head CT is often pursued first as it is easily available and routinely used in adult stroke codes.

We performed a retrospective single institution study of children age 1 month to 18 years seen between 2009 and 2021 who were diagnosed with stroke within 72 hours of symptom onset. Patients were identified using diagnostic codes for AIS were reviewed to confirm diagnosis and chart review was used to extract data about clinical presentation and neuroimaging.

110 children (mean 9.9 years, 52% male) were diagnosed at a mean of 19.7 (median 14.3) hours. Mean time to diagnosis was 19.7 (median 13.6) hours in 34 patients diagnosed on initial head CT, 19.9 hours (med 15.3) in 50 patients with an initial non-diagnostic head CT followed by diagnostic head MRI, and 19.2 hours (median 13.5) in 26 patients patients diagnosed on head MRI alone. In the 24 patients with a diagnostic CT followed by confirmatory MRI, mean time from CT to MRI was 18.5 (median 12.3) hours. In the 50 patients with non-diagnostic CT followed by diagnostic MRI, the mean time from non-diagnostic CT to diagnostic MRI was 11.9 hours (median 8.1) hours. This difference in medians of 4.2 hours (95%CI: -3.4, 12.2), while not statistically significant, suggests clinically significant ordering patterns with room for improvement.

Time to MRI following CT was not significantly different between children with and without diagnostic CT, suggesting that that in patients being evaluated for a suspected acute neurologic process, a negative head CT may be falsely reassuring and delay to diagnosis.