Pure subdural haematomas of arteriolar origin.

Fifteen consecutive cases of subdural haematomas (SDHs) of arteriolar origin operated on during the last twenty years in the Neurosurgical Clinic of the University of Genoa are reported. These SDHs are rare and form as a result of a rupture of a cortical arteriolar branch typically on the vicinity of the Sylvian fissure. They are always in a pure form and never associated with parenchymal lesions. Their aetiology is spontaneous, as in the 40% of our series, or more frequently related to minor traumas. These SDHs are often encountered in elderly patients generally presenting with severe clinical conditions (in the 60% of our patients GCS on admission was < 8). Prompt surgical treatment is required in all cases before further worsening of their neurological condition, even if CT scanning does not reveal parenchymal lesions. The mortality rate is over 50% and mainly relates to the pre-operative GC score. Clinical features, neuroradiological aspects and treatment are discussed and literature reviewed.