External hydrocephalus: a probable cause for subdural hematoma in infancy

Area of Science:

• Pediatric Neurology
• Neuroradiology
• Child Neurology

Background:

• Subdural hemorrhage is a frequent occurrence in infants, with nonaccidental trauma being the leading cause.
• Accidental injuries are the second most common etiology for infant subdural hemorrhages.

Observation:

• Three healthy infants, aged 4-7 months, presented with macrocephaly and were diagnosed with frontal subdural hematoma.
• These infants had prominent extracerebral cerebrospinal fluid spaces, indicative of external hydrocephalus.
• No history of trauma or risk factors for child abuse were identified; skull surveys and ophthalmologic exams were normal.

Findings:

• The infants were neurologically intact and maintained normal developmental milestones during a one-year follow-up.
• A potential link between external hydrocephalus and subdural hematoma development with minimal trauma is suggested.
• Stretching of bridging veins within widened subarachnoid spaces may increase the risk of subdural bleeding.

Implications:

• External hydrocephalus might represent a risk factor for subdural hematoma in infants, even with minimal or no apparent trauma.
• While child abuse must always be considered and ruled out, it may not be the primary cause in all cases of infant subdural hematoma.
• This finding warrants further investigation into the pathophysiology of subdural hematoma in infants with specific neuroanatomical variations.