The Relationship Between Cephalic Index and Chronic Subdural Hematoma

Abstract

A low cephalic index, also called “dolichocephaly” has been observed in patients with chronic subdural hematomas. So we paid close attention to the cephalic index in head trauma patients and evaluated its relationship with chronic subdural hematoma. Sixty-five patients with chronic subdural hematomas who were treated between January. 1983, and December, 1987. and 65 patients aged 40 years or older who were treated for head trauma which caused no intracranial hematoma, randomly sampled, as a control group, a total of 130 patients were studied for cephalic index on plain craniogram. The mean cephalic index was smaller in the chronic subdural hematoma group than in the control group for both males(79.0 vs 82.0) and females( 80.8 vs 82.9 ). The percentage of males with dolichocephaly was significantly higher in the chronic subdural hematoma group (15.1% or 8/53 cases) than in the control group ( 1.9% or 1/53 cases )( p = 0.014 ). The smaller the cephalic index, the greater the rotatory moment in the cranial axial direction. This moment may generate angular acceleration and cause a traction of the bridging vein. Thus, resulting in the onset of chronic subdural hematoma. On the other hand, the same endocrine environment may be related to the development of both dolichocephaly and chronic subdural hematoma. Particular attention should be given to chronic subdural hematoma after head trauma in adults with dolichocephaly on plain craniogram.