Use of quantitative magnetic resonance angiography to stratify stroke risk in symptomatic vertebrobasilar disease.
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BACKGROUND AND PURPOSE: Symptomatic vertebrobasilar disease (VBD) carries a high risk of recurrent stroke. We sought to determine whether a management algorithm consisting of quantitative hemodynamic assessment could stratify stroke risk and guide the need for intervention. METHODS: All patients with symptomatic VBD at our institution are evaluated by a standard protocol including quantitative magnetic resonance angiography (QMRA). Patients are stratified on the basis of the presence or absence of distal flow compromise. Those with low distal flow are offered intervention (surgical or endovascular); all patients receive standard medical therapy. We reviewed the clinical outcome of patients managed with this protocol from 1998 to 2003. RESULTS: Follow-up was available for 47 of 50 patients over a mean interval of 28 months. Stroke and combined stroke/transient ischemic attack free survival at 2 years was calculated using the Kaplan-Meier curve. Patients with normal distal flow (n=31) had an event-free survival of 100% and 96%, respectively. Comparatively, patients with low distal flow (n=16) experienced a 71% and 53% event-free survival, demonstrating a significantly higher risk of recurrent ischemia (P=0.003). Patients with low flow who subsequently underwent treatment (n=12) had an 82% event-free survival. Cox proportional hazards analysis demonstrated that flow status affected event-free survival regardless of covariates. CONCLUSIONS: Patients with symptomatic VBD demonstrating low distal flow on QMRA appear to have a high risk of stroke; conversely, those with normal flow seem to have a benign course and may be optimally managed with medical therapy alone. (+info)
Therapeutic advances in interventional neurology.
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Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in a great expansion of potential therapeutic applications. We discuss therapeutic interventional neurology as applied in clinical practice in one of the two possible ways: 1) embolization leading to occlusion of blood vessels; and 2) revascularization leading to reopening of blood vessels. These procedures can be applied to a broad range of cerebrovascular diseases. In the first section of this review, we will explore the evolution of these interventions to occlude aneurysms, arteriovenous malformations, neurovascular tumors, and injuries. In the second section, revascularization in acute ischemic stroke, stenosis, and dural venous thrombosis will be discussed. (+info)
Rescue revascularization therapy with a stent-in-stent technique for acute intracranial internal carotid artery occlusion.
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A 45-year-old woman presented with progressive stroke due to occlusion of the left internal carotid artery at the level of the cavernous portion (C3/C4). Revascularization was achieved by stent deployment following percutaneous transluminal angioplasty. Stent thrombosis occurred 7 days after primary stenting; it was successfully treated with the stent-in-stent technique. The patient was able to return to her independent life with no sequelae except for slight hemiparesis. In combination with appropriate antiplatelet treatment, the stent-in-stent technique should be considered as a rescue option in patients with re-occlusion of an intracranial stent. (+info)
Multiple spontaneous dissecting aneurysms of the anterior cerebral and vertebral arteries.
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A 50-year-old woman presented with rare multiple dissecting aneurysms that appeared first in the anterior cerebral artery (ACA) and shortly afterwards in the vertebral artery (VA). She initially suffered sudden motor weakness in the left lower limb due to acute brain infarction. Angiography revealed diffuse string sign in the right ACA. Conservative treatment resulted in resolution of the deficits. Follow-up angiography performed 1 year later revealed recovery of the ACA stenosis. Fourteen days later, she complained of sudden headache and became comatose. Computed tomography showed diffuse subarachnoid hemorrhage. Angiography revealed a new right VA dissecting aneurysm involving the posterior inferior cerebellar artery (PICA). The orifice of the dissection was not apparent in the operative field and the dissection extended to the median. The patient underwent extracranial right VA ligation, clipping of the proximal PICA, and revascularization between the right occipital artery and distal PICA. Her postoperative course was uneventful and she was discharged without neurological deficits. VA dissecting aneurysms involving the PICA without evident orifice or extending over the median can be treated by extracranial ligation with clipping of the PICA, followed by revascularization. (+info)
Prediction of the clinical outcome of pediatric moyamoya disease with postoperative basal/acetazolamide stress brain perfusion SPECT after revascularization surgery.
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BACKGROUND AND PURPOSE: We evaluated whether basal/acetazolamide stress brain perfusion SPECT performed after revascularization surgery can predict the further clinical outcome of patients with pediatric moyamoya disease. METHODS: A total of 77 (31 males, 46 females, age 6.6+/-3.2 years) patients with postoperative pediatric moyamoya disease who underwent basal/acetazolamide stress brain perfusion SPECT 6 to 12 months after revascularization surgery and who were followed-up >12 months after SPECT were included. Mean follow-up period after SPECT was 36+/-19 months. Sixty-two patients underwent bilateral ribbon encephaloduroarteriosynangiosis (EDAS), 14 bilateral EDAS, and 1 unilateral EDAS. Ordinal logistic regression analysis using 5 independent variables (infarction on preoperative MRI, age at the first operation, highest Suzuki stage on cerebral angiography, and regional cerebrovascular reserve on postoperative SPECT) against postoperative clinical outcomes was performed. RESULTS: Fifty-one patients had preserved reserve on postoperative SPECT and their clinical outcomes were excellent (30), good (15), fair (4), and poor (2); 26 patients had decreased reserve (excellent, 1; good, 7; fair, 14; poor, 4). On ordinal logistic regression analysis, age at the first operation (P=0.033) and reserve on postoperative SPECT (P<0.001) were statistically significant. CONCLUSIONS: Basal/acetazolamide stress brain perfusion SPECT performed at 6 to 12 months after the indirect bypass operation could predict the further clinical outcome of pediatric patients with moyamoya disease. Patients with decreased cerebrovascular reserve will have remaining neurological deficit and ischemic attacks on follow-up. (+info)
Evaluation of vasomotor reactivity by transcranial Doppler and acetazolamide test before and after extracranial-intracranial bypass in patients with internal carotid artery occlusion.
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BACKGROUND AND PURPOSE: The aim of this trial was to evaluate the effectiveness of extracranial-intracranial bypass with respect to vasomotor reactivity in patients with internal carotid artery occlusions and absent vasomotor reactivity, comparing them with a control group treated conservatively. METHODS: To test vasomotor reactivity in 104 patients with unilateral occlusion of the internal carotid artery, we measured blood flow velocity in the middle cerebral artery by transcranial Doppler sonography both at rest and after injection of acetazolamide. Among the 39 patients who failed to show increased mean blood flow velocity after the acetazolamide test distal to an occluded internal carotid artery by greater than or equal to 10%, 14 subjects subsequently underwent extracranial-intracranial bypass surgery (group A) and 14 age- and sex-matched subjects in whom no such procedure was done composed the control group (group B). Follow-up examinations were performed 3-6 months postoperatively and in the control group 3-6 months after initial examination. RESULTS: Baseline values of the mean blood flow velocity at rest on the affected side were reduced in both groups compared with the contralateral healthy side (group A, 46.0 +/- 15.1 cm/sec; group B, 48.1 +/- 16.7 cm/sec) and revealed only a marginal increase after acetazolamide. The contralateral side showed a normal blood flow velocity at rest and an adequate response to acetazolamide in both groups. On the follow-up examination group A demonstrated a normalized vasodilatory capacity. Blood flow velocity increased significantly after acetazolamide from 41.9 +/- 13.1 cm/sec to 53.5 +/- 16.0 cm/sec (p less than 0.002). In group B, the compromised vasomotor reactivity remained unchanged. CONCLUSIONS: Our results demonstrate that transcranial Doppler sonography together with the acetazolamide test can identify subjects with reduced vasomotor reactivity distal to an occluded internal carotid artery, who may improve hemodynamically by an extracranial-intracranial bypass. (+info)
Early revascularization in a patient with perfusion computed tomography/diffusion-weighted magnetic resonance imaging mismatch secondary to acute vertebral artery occlusion. Case report.
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A 67-year-old woman with a recent history of recurrent ischemic stroke secondary to right vertebral artery stenosis suffered acute onset of left homonymous hemianopsia and the medial longitudinal fasciculus syndrome, which resolved with hyperdynamic therapy. However, consciousness deteriorated 6 hours later. Perfusion computed tomography (CT) revealed regions of prolonged mean transit time in the bilateral cerebellar hemispheres, vermis, brainstem, and right occipital lobe, which were more extensive than the ischemic lesions demonstrated by diffusion-weighted magnetic resonance (MR) imaging. Subsequent cerebral angiography showed occlusion of the right vertebral artery. The patient underwent emergent left superficial temporal artery to left superior cerebellar artery bypass. Postoperatively she demonstrated resolution of the preoperative perfusion CT/diffusion-weighted MR imaging mismatch and improved neurological deficits. Early revascularization in a patient with perfusion CT/diffusion-weighted MR imaging mismatch following acute vertebrobasilar stroke can lead to improvement in cerebral perfusion and neurological function. (+info)
Moyamoya syndrome in an adolescent with essential thrombocythemia: successful intracranial carotid stent placement.
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BACKGROUND: Essential thrombocythemia (ET) is a chronic myeloproliferative disorder with increased frequency of thrombotic events, including transient ischemic attacks (TIAs) and stroke. Moyamoya syndrome is a rare cerebrovascular disease characterized by progressive occlusion of intracerebral arteries with a typical "puff of smoke" angiographic pattern. We report the development of moyamoya syndrome in a patient with ET. CASE DESCRIPTION: The patient is an 18-year-old female who presented at age 13 with recurrent TIAs. Persistent thrombocytosis was found, a diagnosis of ET was made, and treatment with anagrelide was started. Despite normal platelet counts, she experienced recurrent TIAs and stroke. Severe stenosis of the supraclinoid segment of the left internal carotid artery (LICA) and abnormal collateral vessels were found, and moyamoya syndrome was diagnosed on the basis of the characteristic angiographic appearance. An intracranial stent was placed in the LICA, and since then, she has had an uneventful outcome after a 46-month follow-up. CONCLUSIONS: To our knowledge, the development of moyamoya phenomenon has not been reported in ET, and the relationship between these 2 disorders remains unclear. Besides, this is the first intracranial carotid stent implanted successfully in a patient with moyamoya. (+info)