Perimesencephalic nonaneurysmal hemorrhage associated with vein of Galen stenosis

Abstract

First described in 1985, perimesencephalic nonaneurysmal hemorrhage (PMH) is an accumulation of blood in the subarachnoid space surrounding the midbrain that occurs in the absence of an aneurysm or other source of bleeding on angiography.1 While the exact cause of the hemorrhage has been debated, a venous source is likely due to its limited extension, mild clinical course, and good prognosis, all of which point toward a local leakage of venous blood rather than a high pressure arterial source.2 In this article we present two cases of PMH associated with venous hypertension from vein of Galen stenosis. ### Case reports. #### Case 1. A 91-year-old man with a past medical history of ischemic cardiomyopathy, COPD, and recent weight loss presented to the emergency department following acute onset headache and loss of consciousness, leading to fall. There was no history of smoking, hypertension, or anticoagulant use. Neurologically, he showed no focal abnormalities, and had grade 5/5 strength in all extremities across all joints, and had no sensory deficits. A noncontrast head CT scan showed acute blood in the perimesencephalic subarachnoid space and adjacent right parasagittal areas. A catheter angiogram was then carried out which showed stenosis at the vein of Galen junction with the straight …