Successful Use of tPA for Saddle Pulmonary Embolism in Perimesencephalic Non-aneurysmal Subarachnoid Hemorrhage: Case Report

Background: Perimesencephalic non-aneurysmal subarachnoid hemorrhage (PNSH) is characterized by a typical pattern of localized pretruncal hemorrhage on head computed tomography (CT). PNSH is usually associated with a benign clinical course and a lower incidence of complications. The etiology is unknown but has many proposed explanations, including venous injury or rupture followed by thrombosis of a ruptured microaneurysm.

Case description: We present a previously unreported case of a 48-year-old man on apixaban for multiple venous thromboembolisms who presented with the worst headache of his life associated with blurry vision, nausea, and neck stiffness. CT demonstrated a perimesencephalic pattern of blood (Hunt-Hess grade 2, Fisher grade 3). CT angiogram and 6-vessel digital subtraction angiography (DSA) demonstrated no precipitating cause. Systemic tissue plasminogen activator (tPA) was administered on post-bleed day 8 due to obstructive shock from saddle pulmonary embolism and pulseless electrical activity. He was safely discharged to rehabilitation with moderate neurological deficits attributed to ischemic effects of his cardiac arrest.

Conclusions: Symptomatic saddle pulmonary embolism in the setting of intracranial hemorrhage creates conflicting risks of medical intervention. There are no case reports or evidence of the use of systemic thrombolysis in the setting of SAH. Due to the benign natural history of PNSH, tPA may be a safe intervention. Neurointensivists and neurosurgeons should be aware that intravenous tPA was used safely for life-threatening pulmonary embolism in the setting of PNSH. Additionally, the use of tPA without resultant re-bleeding in this case opposes the theory of the presence of a thrombosed ruptured microaneurysm.

Keywords: Angiography; Computed tomography angiography; Perimesencephalic hemorrhage; Pulmonary Embolism; Saddle Embolism; Subarachnoid hemorrhage; tPA.