Post-traumatic hydrocephalus after decompressive craniectomy.

The diagnosis of hydrocephalus after decompressive craniectomy (DC) for severe traumatic brain injury is exclusively radiological in the first 2–3 weeks. The appearance on CT scan of progressive ventricular enlargement is pathognomonic, sometimes preceded by characteristic interhemispheric cerebrospinal fluid collection. The distance of the medial margin of the craniectomy from the midline in the past has been a significant factor for post-traumatic hydrocephalus. To date the largest post-DC cohort series, now reported by Williams, drives us to consider nonsignificant the medial craniectomy margin distance from midline to favour hydrocephalus after DC.