Recurrent, symptomatic, late-onset, contralateral subdural effusion following decompressive craniectomy treated by cranial strapping.

Subdural effusions following decompressive craniotomy for trauma are usually benign, ipsilateral to the craniotomy and resolve spontaneously. Far less common and more dangerous are contralateral subdural effusions causing external cerebral herniation. We report a case of recurrent contralateral effusion and highlight the management dilemmas. Arachnoid tear is probably the cause of these collections. Contralateral subdural effusions should be suspected in patients who have delayed neurological deterioration after an initial improvement particularly in the setting of increased "flap bulge" though they may also be found in patients who remain moribund after initial surgery. There are no clear-cut guidelines on their management due to their rarity. A variety of options like subduro-peritoneal shunt and drainage with simultaneous cranioplasty may be tried. In situations where resources or patient compliance is an issue, tapping the effusion followed by cranial strapping may be tried as was done in our case.