Background  Osteogenesis imperfecta is associated with susceptibility to connective tissue damage, including intracranial but usually extra-axial hemorrhage. Plasminogen activator inhibitor-1 deficiency is a rare fibrinolytic cause of systemic bleeding diathesis.

Objective  To describe a case of a brainstem intraparenchymal hemorrhage associated with connective tissue and coagulation disorders.

Design  Case report.

Setting  Academic medical center.

Patient  A 36-year-old woman with a history of osteogenesis imperfecta presented to the emergency department after an argument, during which she developed left ear pain and right eye esotropia followed by quadriparesis and somnolence. Neuroimaging showed a tegmental mesencephalic hemorrhage.

Main Outcome Measures  Results of computerized tomography, magnetic resonance angiography, and parenchymal imaging; and serum hematologic markers.

Results  No underlying vascular abnormality or mass lesion was found. Among coagulopathic serum markers, only plasminogen activator inhibitor-1 activity level was abnormally low.

Conclusion  Intraparenchymal hemorrhage may occur in the setting of a fibrinolytic inhibitory deficiency and osteogenesis imperfecta.