Midbrain Stroke With Angiogram-Negative Subarachnoid Hemorrhage Mimicking a Perimesencephalic Bleed

Midbrain Stroke With Angiogram-Negative Subarachnoid Hemorrhage Mimicking a Perimesencephalic Bleed

Case Report Midbrain Stroke With Angiogram-Negative Subarachnoid Hemorrhage Mimicking a Perimesencephalic Bleed John P. Ney, MD Angiogram-negative ...

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Case Report

Midbrain Stroke With Angiogram-Negative Subarachnoid Hemorrhage Mimicking a Perimesencephalic Bleed John P. Ney,

MD

Angiogram-negative atraumatic subarachnoid hemorrhage (SAH) in a perimesencephalic pattern on computed tomography (CT) is associated with an almost invariably favorable prognosis with few rebleeds. We report a patient who exhibited a perimesencephalic hemorrhage pattern on CT and negative serial angiograms and who presented with severe neurologic disability from a concurrent midbrain stroke. We contend that both the acute infarction and hemorrhage arose from obliteration of a penetrating end artery. Possible etiologies of angiogramnegative SAH, including perimesencephalic hemorrhage, are discussed. Key Words: Subarachnoid hemorrhage—perimesencephalic hemorrhage—stroke. © 2005 by National Stroke Association

Atraumatic subarachnoid hemorrhage (SAH) is a neurosurgical emergency suggesting ruptured aneurysm. Yet a minority of patients with SAH have no aneurysm and rarely exhibit rebleeding or neurologic deficits. We report a patient with midbrain stroke and angiogramnegative SAH in a perimesencephalic pattern, contrasting with the typical benign course of perimesencephalic hemorrhage (PMH).

Case Summary A 62-year-old man developed headache and bilateral ptosis while at home. A computed tomography (CT) scan of the head obtained at a local emergency department

From the Department of Neurology, Walter Reed Army Medical Center, Washington, DC. Received December 1, 2004; accepted December 6, 2004. The opinions and assertions presented in this article are the private views of the author and should not be construed as the views of the Department of Defense, the U.S. Army, or Walter Reed Army Medical Center. Address reprint requests to John Ney, MD, 6900 Georgia Avenue, NW, Bldg #2, Washington, DC 20307. E-mail: John.Ney@na. amedd.army.mil. 1052-3057/$—see front matter © 2005 by National Stroke Association doi:10.1016/j.jstrokecerebrovasdis.2004.12.007

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revealed subarachnoid blood, prompting transfer to our institution. On examination, the patient responded to commands with no signs of trauma. He had complete opthalmoplegia bilaterally and poorly reactive pupils. His remaining cranial nerve, strength, and sensory tests were normal. He had a coarse kinetic tremor bilaterally and brisk symmetric reflexes and extensor toe signs. Initial and repeat head CT showed subarachnoid blood centered around the brainstem. Brain magnetic resonance imaging (MRI) demonstrated restricted diffusion in the midbrain tegmentum, suggesting infarction. No aneurysm was seen on 2 successive angiograms (Fig 1, A–D). He had no coagulopathy. Two weeks after presentation, his examination findings remained unchanged. The patient required long-term care in a skilled nursing facility.

Discussion PMH represents the majority of angiogram-negative SAHs.1 In PMH, the preponderance of subarachnoid blood is anterior to the brainstem. Blood may extend into the proximal aspects of the anterior and sylvian fissures.2 Presentation typically does not include loss of conciousness or neurologic disability.3 Vasospasm and rebleeding are rare.4 Our patient presented with extensive subarachnoid bleeding, but without ventricular extension or filling of the distal sylvian or anterior fissures.

Journal of Stroke and Cerebrovascular Diseases, Vol. 14, No. 3 (May-June), 2005: pp 136-137

MIDBRAIN STROKE AND ANGIOGRAM-NEGATIVE SUBARACHNOID HEMORRHAGE

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stem infarct has shown a demonstrable intramural hematoma on MRI.9 In our patient, midbrain infarction with SAH makes a venous anomaly less likely. Dissection with normal angiography and no signs of intramural hematoma is dubious. We hold that our patient had obliteration of a midbrain perforating artery, leading to infarction and SAH. Although the pattern of bleeding may mimic PMH, this patient’s course and prognosis were distinctly different from those of a typical PMH.

References

Figure 1. Images taken on day 1 of subarachnoid bleeding. (A) Head CT, noncontrast, shows subarachnoid blood centered around the midbrain without complete filling of the anterior and lateral fissures. (B) Sagittal T1weighted noncontrast MRI shows blood isointense to the brain anterior to the basilar artery flow void. (C) Axial diffusion-weighted MRI shows restricted diffusion in the midbrain, suggesting infarction (D) Anteroposterior view. Right vertebral artery injection does not show aneurysm or dissection.

The etiology of PMH is unknown. A venous bleed has been postulated.5 CT venography of PMH patients had shown an increase in persistent primitive venous drainage patterns.6 Hochberg et al7 reported rupture of a pontine perforating artery found on autopsy in a patient with angiogram-negative SAH complicated by heparin overdosing. Basal ganglia infarctions with angiogramnegative SAH are thought to arise from end-artery obliteration.8 Vertebrobasilar dissection with SAH and brain-

1. van Gijn J, Rinkel GJE. Subarachnoid haemorrhage: Diagnosis, causes, and management. Brain 2001;124:244-278. 2. Rinkel GJ, Wijdicks EF, Vermeulen M, et al. Nonaneurysmal perimesencephalic subarachnoid hemorrhage: CT and MR patterns that differ from aneurysmal rupture. AJNR 1991;12:829-834. 3. van Gijn J, van Dongen KJ, Vermeulen M, et al. Perimesencephalic hemorrhage: A nonaneurysmal and benign form of subarachnoid hemorrhage. Neurology 1985;35: 493-497. 4. Schievink WI, Wijdicks, Spetzler RF. Diffuse vasospasm after pretruncal nonaneurysmal subarachnoid hemorrhage. AJNR 2000;21:521-523. 5. Schievink WI, Wijdicks EF, Piepgras DG, et al. Perimesencephalic subarachnoid hemorrhage: Additional perspectives from four cases. Stroke 1994;25:1507-1511. 6. van der Scaaf IC, Velthuis BK, Gouw A, et al. Venous drainage in perimesencephalic hemorrhage. Stroke 2004; 35:1614-1618. 7. Hochberg FH, Fisher CM, Roberson GH. Subarachnoid hemorrhage caused by rupture of a small superficial artery. Neurology 1974;24:319-321. 8. Tatter SB, Buonanno FS, Ogilvy CS. Acute lacunar stroke in association with angiogram-negative subarachnoid hemorrhage. Stroke 1995;25:891-895. 9. Murakami K, Takahashi N, Matsumura N, et al. Vertebrobasilar artery dissection presenting with simultaneous subarachnoid hemorrhage and brain stem infarction: Case report. Surg Neurol 2003;59:18-22.