Computed tomographic evolution of post-traumatic subdural hygroma in young adults.

The authors report on two cases of post-traumatic subdural hygroma that were encountered in young adults. Serial computed tomograms were taken immediately following trauma and for more than 4 weeks thereafter. In the case of a 28-year-old man with a skull fracture, an initial CT scan revealed a thin crescentic subdural collection in the right frontal area. A successive CT scan on the 36th postoperative day revealed developed subdural hygroma, and the CSF-like fluid was surgically evacuated. In the second case, involving an 18-year-old man, a very thin bifrontal subdural collection was found on the initial CT scan, and on the 15th post-traumatic day CT scan demonstrated a bifrontal subdural hygroma. No surgical treatment was carried out, and the follow-up CT scan on the 29th post-traumatic day demonstrated no change in size. The two young patients were slightly symptomatic during the period involved, and the repeat unenhanced CT scans showed subdural lesions of less than brain density, even in the chronic stage.