Recently, Massand et al¹ reported 4 more patients with ruptured isolated spinal artery aneurysms successfully treated by surgery. Subarachnoid hemorrhage (SAH) due to isolated spinal aneurysms without associated arteriovenous malformation (AVM) or other entities such as aortic coarctation or vasculitides is very rare. Only approximately 20 cases of spinal SAH due to rupture of isolated spinal aneurysms have been reported until now. The clinical hallmarks of spinal SAH are back pain and, later, cranial and meningeal symptoms. The angiographic appearance of the spinal aneurysms tends to be fusiform along the course of the artery.¹, ² An inflammatory process, dissecting aneurysms, and no evident cause are discussed as the underlying etiology.

Perhaps spinal artery aneurysms are more frequent than we believe and should, accordingly, be diagnosed more often by MR imaging and MR angiography in cases of spinal SAH. Recently, we detected our fourth patient within 3 years with isolated spinal aneurysm at the descending anterior spinal artery at level T12. At the time of admission, our patient had paraplegia and symptomatic cerebral vasospasms, which had already induced large bilateral hemispheric infarcts. Therefore, the prognosis was judged unfavorable. There were no signs for rerupture of the aneurysm. Palliative treatment was performed until the death of the patient 23 days after admission due to a pneumogenic sepsis.

Histopathologic analysis showed no dissection and most notably did not show the anticipated inflammatory process.

There is still controversy about the treatment strategy. Whereas in the article of Massand et al¹ all 4 patients were treated surgically, we preferred a wait and see strategy with conservative treatment. Spontaneous aneurysm occlusion occurred in all of our 3 published cases.²

Comparing the 2 groups, we found that all these patients showed favorable outcome with no or only minor neurologic deficits. The main reason for the fatal outcome of our last patient was the fact that spinal MR imaging was not performed and an SAH was not well recognized before admission. Because of the small number of case reports, there is no clear indication for treatment. At first, angiography is necessary to detect the source of the spinal SAH. A mass effect compressing the spinal cord seems to be perhaps the only indication for treatment. The mass effect can result from a blood clot or the aneurysm size, though most reported aneurysms were small. Transcranial Doppler sonography controls are also necessary to detect cerebral vasospasm, and CSF drainage might prevent arachnoiditis. Aneurysms involving the artery of Adamkiewicz as well as the anterior spinal artery have a risk of spinal infarct if the aneurysm is occluded.

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