gms | German Medical Science

Objective: Vascular malformations within the foramen magnum and upper cervical canal are rare. Diagnosis is cumbersome and neurosurgical treatment is hazardous. We report on 6 cases.

Methods: Age ranged from 37 to 77 years, 4 male and 2 female patients. Diagnosis at the time of referral included “normal pressure hydrocephalus”( one case), “subarachnoid haemorrhage” (two cases), “spinal stenosis”(two cases) or “myelitis”. Imaging techniques included magnetic resonance (MR) imaging, MR angiography and highly selective segmental cervical angiography with microcatheters. Surgery was performed with electroneurophysiological monitoring. .

Results: Angiography revealed three arteriovenous fistulae within the foramen magnum, a giant vertebral artery aneurysm within the foramen magnum and two patients with an intradural arteriovenous malformation at the C2 level. The fistulae and the aneurysm were occluded using microclips. The edema of the cervical myelon of the patients with the fistulae resolved with marked recovery of gait. The hydrocephalus of the patient with the giant vertebral aneurysm also resolved with good recovery.The arteriovenous malformations at the C2 level were coagulated. One of these patients subsequently needed a ventriculoperitoneal shunt. The other suffered some transient weakness of the ipsilateral arm.

Conclusion: In all patients suspicion of a vascular malformation was raised after an initially misleading diagnosis. The decisive hint came from scrupulous evaluation of MR imaging data but diagnosis was only confirmed with selective arteriography. For proper identification of the malformation and planning of the surgical procedure a highly selective segmental spinal arteriography appears mandatory.