Perimesencephalic Nonaneurysmal Subarachnoid Hemorrhage: Review of the Literature

To the Editor: We read with great interest the article by Schwartz and Solomon (1). We present a recent case treated at our institution, which emphasizes the significance of their review and observation that this is an infrequently reported entity in the North American neurosurgical literature. A 62-year-old woman developed a severe headache and neck stiffness approximately 10 days before her hospitalization. She did not report any unusual neurological symptoms and denied recent trauma. Her neurological findings were normal, except for a subtle dysmetria and dysdiadochokinesia of the left upper extremity. A computed tomographic scan of the brain(Fig. 1) revealed a subarachnoid hemorrhage (SAH) in the prepontine region. The patient underwent cerebral angiography, which demonstrated no vascular anomaly or vasospasm. Subsequent management included magnetic resonance imaging (MRI) of the brain (Figs. 2 and 3) and spinal axis. The images revealed nothing abnormal, except for the prepontine hemorrhage, and subsequent cerebral angiography was performed approximately 1 week after the initial angiography. The patient was eventually discharged and was instructed to follow-up with a neurosurgical group at a university medical center for a second opinion. She obtained a third cerebral angiogram, which revealed nothing abnormal.FIGURE 1: Computed tomographic scan of the brain, demonstrating prepontine SAH (arrow).FIGURE 2: T1-weighted (TR, 500 ms; TE, 18 ms) magnetic resonance image of the brain. No evidence of occult vascular anomaly was observed. The arrow indicates prepontine SAH.FIGURE 3: T2-weighted (TR, 4000 ms; TE, 17 ms) magnetic resonance image of the brain, demonstrating prepontine SAH(arrow).That neurosurgeons at two different institutions were unfamiliar with this particular type of SAH emphasizes the significance of the article by Schwartz and Solomon (1). We wish that the article had been published 6 months sooner. Thomas R. Hurley Jorge Balandrin Oak Lawn, Illinois