Pure subdural hematomas: a postmortem analysis of their form and bleeding points.

OBJECTIVE: Although the literature concerning subdural hematomas (SDHs) is vast, few data are available as to the sources and related clinical differences of SDHs. Pure SDHs of arterial versus venous origin should be compared in terms of cause, size, space-occupying effect, and form.

METHODS: We analyzed data from 46 patients who died as a result of pure SDHs. Twenty-three SDHs resulted from bridging vein ruptures and 23 from torn cortical arteries. We performed a morphometric analysis of the intracranial situation on the horizontal plane at the level of the greatest fronto-occipital diameter. We included in our analysis the clinical one-dimensional parameters (e.g., hematoma thickness, midline shift); the areas of the hemispheres, the SDHs, and their displacement; and the hematoma volume.

RESULTS: Most of the investigated postmortem characteristics of both types of hematomas were similar, with the exception of the form and the midline shift. SDHs resulting from arterial ruptures (which are generally located in the temporoparietal region) differ in form from those caused by bridging vein ruptures (which typically rupture in the frontoparietal parasagittal region).

CONCLUSION: The form difference allows the probable rupture site to be estimated; this observation might prove useful for clinical purposes.