Abstract
It has been our observation that in the presence of concave deformity of the skin flap following large decompressive craniectomy, unexpected neurological deterioation would occur independently of the primary disease or natural improvement would be unduly impaired, and that such unfavorable phenomena were reversed by cranioplasty. In order to know the true incidence and the nature of this phenomenon, 33 consecutive cases were analyzed. Nine of 30 patients (30%) with flat or sinking skin flap showed prompt improvement following cranioplasty. The best 'candidates' for maximum benefit of cranioplasty were those with moderate grade neurological deficits in addition to the presence of concave deformity of skin flap (successful rate of 88%; 7 among 8 patients). Other factors influencing the results were primary disease (favorable to meningioma), time elapse from the decompressive craniectomy, presence of shunt system, CSF pressure and EEG changes before and after cranioplasty. EEG changes had well coincided with clinical course.
The characteristic phenomenon would be described as “the syndrome of the sinking skin flap, ” considering that neurological deterioration may be due solely to effect of concave deformity of the skin flap upon the underlying brain tissue.
