“…Also, decompressive craniectomy [ 13 , 17 ] and the presence of subdural hygroma after craniectomy [ 29 ] seem to increase the risk for PTH. In craniectomy, the proximity of the craniotomy to the skull midline [ 4 , 43 ] might increase the risk as well. Other possible risk factors for PTH increased age, cerebrospinal fluid infection, and intraventricular hemorrhage [ 4 , 13 ].…”