Intracerebral hemorrhage: non-hypertensive causes.

SPONTANEOUS, non-traumatic intracerebral hemorrhage (ICH) in the adult is most commonly secondary to hypertensive cerebrovascular disease. In 70-90% of cases of spontaneous ICH, arterial hypertension is the presumed cause. 1 These hypertensive hemorrhages show a predilection for certain anatomic locations: the basal ganglia (the putamen in particular), the subcortical white matter, and the thalamus account for 35%, 25%, and 20% of ICHs, respectively, whereas the posterior fossa locations, the cerebellum and pons, are responsible for only 10% and 5% of the cases. 2 Irrespective of their anatomic locations, the common pathogenesis in these hemorrhages involves the hypertension-induced degeneration of the media of small (50-200 micra) arteries called "lypo-hyalinosis," 3 and/ or the formation of "microaneurysms", both of which occur preferentially in perforating or small sub-cortical arteries, thus resulting in the characteristic anatomic distribution of hypertensive ICH.