Aspirin is associated with an increased risk of subdural hematoma in normal-pressure hydrocephalus patients following shunt implantation

OBJECT: In this paper the authors investigate whether shunt-treated patients with normal-pressure hydrocephalus receiving aspirin therapy are at increased risk of developing subdural hematoma (SDH). METHODS: Records from 80 consecutive patients who had undergone implantation of a cerebrospinal fluid shunt for the treatment of normal-pressure hydrocephalus were retrospectively reviewed. RESULTS: Eleven cases of symptomatic SDH occurred, all among patients receiving aspirin or clopidogrel. The 5-year survival estimate was 0.3 (p < 0.0001) for users of aspirin and the hazard ratio was 12.8 (95% CI 3.1-53). CONCLUSIONS: Patients on an aspirin therapy regimen have a markedly increased risk of SDH after a shunt has been implanted for the treatment of normal-pressure hydrocephalus. Users of clopidogrel may have an even greater risk.