Neuroimaging patterns of brain injury in children following near-drowning

Near-drowning is a prevalent cause of hypoxic ischemic injury in children and young adults. Despite its clinical significance, there is a lack of studies examining the brain magnetic resonance imaging (MRI) findings associated with near-drowning incidents.

The aim of this study is to identify patterns of imaging findings on brain MRI scans of children who have experienced near-drowning.

This retrospective study included children who experienced near-drowning incidents and had brain MRI scans available for review between November 2000 and September 2023. Abnormal MRI findings were categorized into three patterns: (1) gray matter injury, (2) white matter injury, and (3) combined gray matter and white matter injury. For each category, we distinguished those with MRI scans obtained in the acute setting and those with MRI studies performed in the non-acute setting. When available in the electronic medical records (EMR), collected parameters for patients with acute MRI scans included: sex, age, best estimate of the water temperature, water type, duration of submersion, and whether cardio pulmonary resuscitation (CPR) was performed.

The study included 50 patients (32 males, 18 females) with a median age of 32.9 (interquartile range, 19.9-69.2) months. Of these patients, 28 had acute MRI scans available, while 22 had only non-acute MR imaging. Among the 28 patients with acute MRI, 12 (42%) had primarily cortical and/or deep gray matter injury without visible white matter injury, 8 (29%) had both cortical and/or deep gray and white matter injury, and 8 (29%) were normal. The median age was 26.7 (interquartile range, 16.6-43.6) months in the acute MRI group and 42.9 (interquartile range, 27-130.3) months in the non-acute MRI group. Water temperature information was available in 25/50 cases, all occurring in warm water (9 in a bathtub and 16 in a pool). In patients with isolated gray matter injury, the submersion duration was < 3 min in 7/12 patients, while 5/12 did not have data on submersion duration. CPR was performed in 8 patients, with data unavailable for 4 cases. In patients with gray and white matter injury, submersion duration was < 3 min in 1/8 cases, with data not available for 7 patients. CPR was performed in 5 patients, with data unavailable for 3 cases. In patients with normal findings the submersion duration was < 3 min in 2/8 patients, and CPR was performed in all 8 patients.

Our study suggests that children who suffer near-drowning are likely to have gray matter injury on MRI obtained within the first 7 days after injury. In contrast, delayed white matter lesions, may develop weeks after the initial hypoxic-ischemic event and may be observed in chronic imaging either alone or in combination with gray matter lesions. These imaging patterns appear to resemble those described in neonatal hypoxic-ischemic injuries, although further studies are needed to confirm these associations.