Subdural Hematoma Over the Convexity
Subdural hematomas are due to rupture of the superficial cortical veins that bridge through the dura mater. Patients with subdural hematomas over the convexity present with focal seizures, hemiparesis, and gaze preference. These findings may be followed by the development of a unilateral third cranial nerve deficit (ptosis and poorly reactive pupil) if herniation occurs. The diagnosis is established by CT or MRI of the brain. Treatment, if necessary, is surgical either by subdural taps or direct surgical intervention. Subdural hematoma should be drained if seizures persist despite administration of phenobarbital, if the subdural collection is large, or if there is evidence of midline shift or impending transtentorial herniation. More about... 250, 286

Subarachnoid Hemorrhage
Subarachnoid hemorrhage may be primary or secondary. Primary subarachnoid hemorrhage results from bleeding directly into the subarachnoid space due to structural vascular accidents (rupture of an aneurysm and an arteriovenous malformation), a coagulopathy, or an unknown cause. More about... 251