(Stroke. 1998;29:2514-2516.)
© 1998 American Heart Association, Inc.
Original Contributions |
From the Departments of Neurology (E.F.M.W.), Neurosurgery (W.I.S.), and Diagnostic Radiology (G.M.M.), Mayo Clinic, Rochester, Minn.
Correspondence to E.F.M.Wijdicks, MD, Department of Neurology, W8A, Mayo Clinic, 200 First St SW, Rochester, MN 55905. E-mail wijde{at}mayo.edu
| Abstract |
|---|
|
|
|---|
MethodsWe used MR imaging of the brain with routine sequences, gadolinium enhancement, and additional thin T1-weighted axial sections following a triple dose of contrast.
ResultsWe performed MR imaging of the brain in 18 patients with a pretruncal nonaneurysmal subarachnoid hemorrhage. The focal nature of the subarachnoid hemorrhage exclusively in front of the brain stem was confirmed in 14 patients studied within 7 days of the ictus. No vascular abnormalities were found in 17 cases, including 14 patients with gadolinium enhancement. An incidental capillary telangiectasia was found in 1 patient. Fluid-attenuated inverse recovery MR additionally documented blood in the sulci due to cerebrospinal fluid recirculation of blood. Five patients underwent MR imaging of the spine, and no arteriovenous malformations were found.
ConclusionsMR imaging did not reveal a source of pretruncal subarachnoid hemorrhage. The cost of MR imaging probably outweighs the benefit in the evaluation of this variant of subarachnoid hemorrhage.
Key Words: subarachnoid hemorrhage angiography magnetic resonance imaging
| Introduction |
|---|
|
|
|---|
After the initial cerebral angiogram is performed, it is common practice to exclude an arteriovenous malformation or venous angioma in the brain stem or cervical spine by MR imaging. No large series of MR imaging in this subset of subarachnoid hemorrhage have been reported since a preliminary study with 4 normal MRIs involving only axial images.3 We report a review of MR imaging in pretruncal subarachnoid hemorrhage. Our study indicates that MR imaging probably is not a cost-effective diagnostic test in the evaluation of this benign clinical entity.
| Subjects and Methods |
|---|
|
|
|---|
| Results |
|---|
|
|
|---|
|
|
| Discussion |
|---|
|
|
|---|
Our series is the first large study of MR imaging in pretruncal nonaneurysmal subarachnoid hemorrhage. Axial and sagittal views demonstrated the extension of the hemorrhage in the cisterns exclusively in front of the brain stem but failed to show a vascular lesion in 17 of 18 patients. Our previous finding of a capillary telangiectasia on MRI in 1 case suggested a venous etiology of this disorder.4 However, we were unable to confirm this finding, which strongly suggests that this abnormality has been incidental. FLAIR images additionally showed recirculation of subarachnoid blood over the sulci. To our knowledge, this is a new observation in this subset of subarachnoid hemorrhage, but it should not be mistaken for a more diffuse pattern of subarachnoid hemorrhage indicating a possible aneurysmal source. Small lesions were found in the cerebellum and thalamus, likely representing emboli associated with repeated vertebral angiograms.
Our study sample consisted of only 18 MR brain scans. Thus, the 95% confidence interval by the binomial distribution for 1 of 18 (5.6%) is relatively wide (0.1% to 27.3%). Nonetheless, we believe that routine MRI of the brain and spine unnecessarily adds to the cost of evaluation. Perhaps MRI of the spine should be performed only in patients with clinical leads of a ruptured spinal arteriovenous malformation. MRI of the brain may also be useful only to confirm subarachnoid hemorrhage in patients with ambiguous CT scans, such as blood predominantly in the prepontine cisterns, but in all our patients imaged with high-resolution CT scans, the subarachnoid hemorrhage was clearly identified. Nonetheless, over time, newer technologies of MRI will be developed; therefore, MRI as a research tool to investigate the cause of this puzzling but benign variant of subarachnoid hemorrhage may remain useful.
Received July 13, 1998; revision received August 17, 1998; accepted September 9, 1998.
| References |
|---|
|
|
|---|
2. Schievink WI, Wijdicks EFM. Pretruncal subarachnoid hemorrhage: an anatomically correct term for perimesencephalic hemorrhage. Stroke.. 1997;28:2572. Letter.
3. Rinkel GJ, Wijdicks EFM, Vermeulen M, Ramos LMP, Fanghe HJG, Hasan D, Meivers LC, van Gijn J. Nonaneurysmal perimesencephalic subarachnoid hemorrhage: CT and MR patterns that differ from aneurysmal rupture. AJNR Am J Neuroradiol.. 1991;12:829934.[Abstract]
4.
Wijdicks EFM, Schievink WI. Perimesencephalic
nonaneurysmal subarachnoid hemorrhage:
first hint of a cause? Neurology.. 1997;49:634636.
5.
Du Mesnil de, Rochemont R, Heindel W, Wesselman C,
Kruger K, Lanfermann H, Ernestus RI, Neveling M, Lackner K.
Nontraumatic subarachnoid hemorrhage value of repeat
angiography. Radiology.. 1997;202:798800.
6. Schievink WI, Wijdicks EFM, Ebersold M, Nichols DA, Piepgras DG. Perimesencephalic subarachnoid hemorrhage: additional perspectives from four cases. Stroke.. 1994;25:15071511.[Abstract]
7. Deveikis JP, Allen RB, Dickinson LD, Ross DA. Cervical medullary arterial venous fistulae: a frequently unrecognized etiology of subarachnoid hemorrhage. Paper presented at: 31st Annual Meeting of the American Society of Neuroradiology; June 2327, 1996; Seattle, Wash.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Stroke Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1998 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |