Incidence and causes of intracranial hemorrhage in infancy: a prospective surveillance study after vitamin K prophylaxis.

In order to evaluate the effect of vitamin K prophylaxis on the incidence of intracranial hemorrhage (ICH) in infants aged from 1 week to 12 months, a prospective surveillance study, from 1974 to 1988, was performed on the well-defined population of Nagasaki Prefecture, Japan. The incidence of ICH in infancy markedly decreased, from 34.3/100,000 to 10.1/100,000 live births, with the oral administration of vitamin K2 at both birth and 1 week, or with additional supplementation at 1 month of age. The diminished incidence was attributed to the decreased occurrence of acute ICH due to late hemorrhagic disease (LHD), a late onset form of vitamin K deficiency, and chronic subdural hematoma. On comparing the possible etiological factors, and clinical and laboratory findings between these 2 groups, it became apparent that chronic subdural hematoma shared some etiological factors (such as breast-feeding, liver dysfunction and no supplementation of vitamin K) with LHD. Furthermore, chronic subdural hematoma developed in some patients who had previously had acute ICH due to LHD. These findings suggest that coagulopathy due to vitamin K deficiency, including LHD, is causally related in the majority of, if not all, cases of chronic subdural hematoma without any history of trauma or central nervous system infections.