Vertebrobasilar Dissection Research Articles

Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation.

Potential precipitating events and risk factors for vertebrobasilar artery dissection were reviewed in an analysis of the English language literature published before 1993. To assess the literature pertaining to precipitating neck movements and risk factors for vertebrobasilar artery dissection in an attempt to determine whether the incidence of these complications can be minimized. Vertebrobasilar artery dissection and occlusion leading to brain stem and cerebellar ischemia and infarction are rare but often devastating complications of cervical, manipulation and neck trauma. Although various investigators have suggested potential risk factors and precipitating events, the basis for these suggestions remains unclear. A detailed search of the literature using three computerized bibliographic databases was performed to identify English language articles from 1966 to 1993. Literature before 1966 was identified through a hand search of Index Medicus. References of articles obtained by database search were reviewed to identify additional relevant articles. Data presented in all articles meeting the inclusion criteria were summarized. The 367 case reports included in this study describe 160 cases of spontaneous onset, 115 cases of onset after spinal manipulation, 58 cases associated with trivial trauma, and 37 cases caused by major trauma (3 cases were classified in two categories). The nature of the precipitating trauma, neck movement, or type of manipulation that was performed was poorly defined in the literature, and it was not possible to identify a specific neck movement or trauma that would be considered the offending activity in the majority of cases. There were 208 (57%) men and 158 (43%) women (gender data not reported in one case) with an average age of 39.3 +/- 12.9 years. There was an overall prevalence of 13.4% hypertension, 6.5% migraines, 18% use of oral contraception (percent of female patients), and 4.9% smoking. In only isolated cases was specific vascular disease such as fibromuscular hyperplasia noted. The literature does not assist in the identification of the offending mechanical trauma, neck movement, or type of manipulation precipitating vertebrobasilar artery dissection or the identification of the patient at risk. Thus, given the current status of the literature, it is impossible to advise patients or physicians about how to avoid vertebrobasilar artery dissection when considering cervical manipulation or about specific sports or exercises that result in neck movement or trauma.

Clinical characteristics of vertebrobasilar artery dissection.

Sixteen patients with the diagnosis of vertebral or basilar artery dissection who were admitted at the Seoul National University Hospital from 1972 to 1996 are described. During the same period, we encountered 76 patients with posterior circulation aneurysms, so the vertebrobasilar artery dissection was 21% of posterior circulation aneurysms. The mean age was 44 years, and male predominated. Nine patients presented with subarachnoid hemorrhage (SAH) and seven with ischemic symptoms. The characteristic angiographic finding of patients with SAH was aneurysmal dilatation (pseudoaneurysm) in eight of nine cases. In cases of ischemic symptoms, only one case had aneurysmal dilatation. Some other angiographic findings were demonstrated such as string sign, tapered narrowing, complete occlusion, or double lumen. Clinical course of SAH group was much different from that of ischemic group. Rebleeding occurred in three patients of SAH group; immediately after the rebleeding all patients became comatose, but after extraventricular drainage, all patients with rebleeding recovered rapidly. In SAH group, four of nine cases died but there was no mortality in the ischemic group. These four patients showed signs of stem failure, when computed tomography (CT) demonstrated no evidence of additional bleeding and follow-up CT showed the infarction at a part of stem and/or cerebellum. Vasospasm or sudden extensive extension of dissection could be the cause of death. Surgical management was performed in three patients, endovascular intervention in four, and conservative management in two. The patients with incomplete embolization or conservative management had poor outcome. In ischemic group, all underwent conservative management including anticoagulation and/or antiplatelet therapy. On follow-up, most of the patients with ischemic symptoms made complete or very good recoveries.

出血型椎骨脳底動脈系解離性動脈瘤

Fifteen patients of ruptured intracranial vertebrobasilar artery dissection (VBDA) were studied to clarify the clinical problems during treatment. Subsequent rebleeding occurred in 5 of the 15 cases (33.3%) and the mortality rate of patients with rebleeding was 40%. All subsequent rebleeding cases were VBDA of the distal to PICA type. These patients were divided into two groups consisting of a surgical treatment group (chronic stage) with 9 cases and a nonsurgical treatment group with 6 cases. Surgical procedures included proximal occlusion (PO) of the vertebral artery in 7 patients, wrapping in 1 and direct clipping in 1. Postoperative complications occurred in 3 patients by PO. Although proximal occlusion seemed to be a simple and useful method to prevent rebleeding, the occurrence of ischemic complication remains to be solved. Further study is needed to determine the best treatments, including PO for VBDA.

O-22-334 - Unruptured vertebrobasilar dissecting aneurysms. Symptoms and treatment

O-22-334 - Unruptured vertebrobasilar dissecting aneurysms. Symptoms and treatment

Extracranial and intracranial vertebrobasilar dissections: diagnosis and prognosis

OBJECTIVESTo compare the diagnosis and prognosis of extracranial versus intracranial vertebral artery dissections without intracerebral haemorrhage.METHODSTwenty two vertebral artery dissections were defined by intra-arterial angiography and classified in two groups:...

Vertebrobasilar Dissection in a Duplicated Cervical Vertebral Artery: A Possible Pathoetiologic Association?

A thirty-eight-year-old man with extensive spontaneous vertebrobasilar dissection in asso ciation with duplication of the ipsilateral proximal vertebral artery is described. He had no relevant medical history. The development of a spontaneous arterial dissection in a duplicated arterial system suggests a pathoetiologic association that may further expand the list of cerebrovascular pathology occurring with fenestration/duplications.

Recurrent subarachnoid hemorrhage from untreated ruptured vertebrobasilar dissecting aneurysms.

The clinical characteristics of vertebrobasilar dissecting aneurysms occurring with subarachnoid hemorrhage (SAH) were reviewed in 42 patients, with particular focus on the time, incidence, and outcome in association with subsequent rupture. Twenty-nine patients underwent 31 surgical procedures, and the remaining 13 patients were managed without surgery. Surgical details included 19 proximal vertebral artery obliterations (including 1 case of endovascular surgery using balloon occlusion), 9 trappings, 1 wrapping, 1 bleb clipping, and 1 bleb clipping combined with wrapping. Surprisingly, subsequent rupture occurred in 30 (71.4%) of the 42 patients. Excluding one patient with postoperative rupture, 29 patients suffered a subsequent rupture in the unsecured stage. Of these 29 patients, 19 were operated on after the subsequent rupture and 10 were not operated on because of deteriorated clinical condition (9 patients) or anatomic considerations (1 patient). Of the 30 patients that suffered a subsequent rupture, 14 died. Twelve of the deaths were directly related to the second episode of rupture. Of the 12 patients who did not suffer a subsequent rupture, 10 underwent operations and there were no operative deaths. Only one patient died as the result of the initial critical SAH. The mortality (46.7%) of the patients with subsequent rupture was significantly higher (P < 0.05) than that (8.3%) of the patients without subsequent rupture. Seventeen (56.7%) of the 30 subsequent ruptures occurred within 24 hours after the first SAH, and 24 (80%) occurred within the first week. Six (66.7%) of the 9 patients operated on within 24 hours after the first SAH and 11 (68.8%) of the 16 patients operated on within a week suffered preoperative subsequent ruptures.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging study of intracranial vertebrobasilar artery dissections.

The purpose of this study is to demonstrate the magnetic resonance features of intracranial vertebrobasilar artery dissections and to determine the potential and limitations of magnetic resonance imaging in their diagnosis. We studied five consecutive patients with angiographically verified intracranial vertebrobasilar artery dissection with magnetic resonance imaging (0.5 T) in regard to the shapes of the intramural hematoma and the chronological change of its signal intensity. We also estimated the sensitivity of magnetic resonance imaging for diagnosing dissection. We observed intramural hematoma in four patients on the first magnetic resonance scan and in all five patients during the course of the study. The shapes of the intramural hematomas were curvilinear, crescentic, "bamboo-cut," "band-like," and spotty. The intensity of the intramural hematoma varied according to its age. On the T1-weighted and the proton images, the intramural hematomas appeared isointense to slightly hyperintense in the first few days and became hyperintense thereafter. The intramural hematomas became isointense or unrecognizable 2 months after onset. The T1-weighted image and the proton images were superior to the T2-weighted image in demonstrating the intramural hematomas. Magnetic resonance imaging is a sensitive tool for diagnosing intracranial vertebrobasilar artery dissection, particularly in the subacute to early chronic stage. Magnetic resonance imaging is complementary to angiography in that it can directly visualize intramural hematomas.

Migraine and vertebrobasilar dissection: Case reports

We report two patients with chronic migraine headaches who developed vertebrobasilar arterial dissections. In both cases, there was a change in both the character and location of the headaches, which prompted further evaluation with magnetic resonance imaging and angiography, which led to the diagnosis. Other possible risk factors for dissection in these patients included hypertension, exercise, and chiropractic manipulation. Both patients were treated with anticoagulation and recovered with little to no neurologic deficit. A review of the literature relating migraine and arterial dissection suggests that there may be an association. Although more extensive controlled studies are needed to demonstrate the significance of this association, we suggest that the diagnosis of cervicocranial arterial dissection be strongly considered in migraine patients who develop an abrupt change in the nature of their headaches.

椎骨脳底動脈解離の6例

Six adults with spontaneous dissection of the vertebrobasilar system are reported. Clinically, 2 patients presented with subarachnoid hemorrhage and 4 with brain-stem ischemia. In all patients, angiography demonstrated fusiform dilatation and constrictions of the involved vessel, which were called “pearl and string”sign. Among these, 2 patients of subarachnoid hemorrhage and one patient with definite dissecting aneurysm that did not improve in spite of angiographic monitoring were surgically treated. Three other patients were treated conservatively with rather good clinical results. Ischemic type of vertebrobasilar dissection must be angiographically monitored, because of spontaneous healing of dissection. In dealing with dissection of vertebrobasilar arteries, because only severe headache develops before ischemic symptoms appear, great care must be taken for these patients. MRI is one of the most reliable neuroimaging methods for detecting dissection.

“Dolichoectatic” Intracranial Vertebrobasilar Dissecting Aneurysm

We report five patients with intracranial vertebrobasilar dissecting aneurysms, all of whom had ischemic symptoms. Angiographically, four of the five cases revealed distention and elongation of the vertebrobasilar artery like dolichoectasia and one irregular stenosis, the so-called "string sign". Magnetic resonance imaging disclosed all dolichoectatic dissecting lesions by demonstrating intimal flaps, double lumen, or subacute clot in the false lumen. We also present a successful demonstration of slow flow in the false lumen by gradient refocused magnetic resonance imaging scan with partial flip angle by the cardiac gating method. It is suggested that many of the classical "dolichoectasia" may include dissecting lesions.

Contrasting effects of enalapril and metoprolol on proteinuria in diabetic nephropathy.

To assess whether angiotensin converting enzyme inhibition reduces proteinuria in diabetic nephropathy more than blood pressure reduction with other antihypertensive treatment. Prospective, open randomised study lasting eight weeks in patients with diabetic nephropathy. Outpatient nephrology clinics. 40 Patients with type I diabetes and diabetic nephropathy with reduced renal function. Antihypertensive treatment with enalapril or metoprolol, usually combined with frusemide. Arterial blood pressure and urinary excretion of albumin and protein. Arterial blood pressure after eight weeks was 135/82 (SD 13/7) mm Hg in the group given enalapril and 136/86 (16/12) mm Hg in the group given metoprolol. Proteinuria and albuminuria were similar in both groups before randomisation. After eight weeks' treatment, the geometric mean albumin excretion was 0.7 (95% confidence interval 0.5 to 1.2) g/24 h in the patients given enalapril and 1.6 (1.1 to 2.5) g/24 h in the patients given metoprolol (p less than 0.02). The proteinuria was 1.1 (0.7 to 1.7) and 2.4 (1.6 to 3.6) g/24 h respectively (p less than 0.02). Antihypertensive treatment with enalapril reduced proteinuria in patients with diabetic nephropathy more than an equally effective antihypertensive treatment with metoprolol. This points to a specific antiproteinuric effect of the angiotensin converting enzyme inhibitor independent of the effect on systemic blood pressure.

Proximal clipping of dissecting intracranial vertebral aneurysm — effect of balloon Matas test with neurophysiological monitoring

A case of repeated subarachnoid haemorrhage (SAH) caused by rupture of a dissecting intracranial vertebral aneurysm is reported. The clinical manifestations, angiographic findings, pre-operative assessment with neurophysiological monitoring, and surgery are presented. A review of the literature suggests that this type of intracranial aneurysm is being recognized with increasing frequency in SAH and fatality, and therefore exploration and treatment of vertebrobasilar (V-B) dissecting aneurysms is necessary. We emphasize that a balloon Matas test with monitoring of somatosensory evoked potentials (SEP), auditory brain stem responses (ABR), and its wedge pressure in occluding the vertebral artery before operation are objective assessments of treatment for dissecting intracranial vertebral aneurysm.

Dissecting and fusiform aneurysms of vertebro-basilar systems

The magnetic resonance (MR) findings of three cases with vertebro-basilar dissecting aneurysms (DA) were compared with those of two cases with vertebro-basilar fusiform aneurysms (FA). No abnormal findings, excepting a dilatation of a signal-void area corresponding to the arterial blood flow, were shown on the MR images in the patients with a FA. In contrast to the FA cases, various abnormalities were detected by the MR studies in all three DA cases. An intimal flap and a double lumen were demonstrated in one case. An intra-mural hematoma was shown in one case. A hematoma neighboring the parent artery was demonstrated in two cases. MR imaging was thought to be useful for detecting intracranial vascular lesions, such as a DA, and for discriminating between a DA and a FA.

Vertebral Dissecting Aneurysm associated with Medial Mucoid Degeneration

An autopsy case of intracranial vertebral dissecting aneurysm associated with medial mucoid degeneration is reported and 54 cases of vertebro-basilar dissecting aneurysm in the literature are reviewed. A 37-year-old man with history of hypertension was admitted in a semicomatose state. Computed tomographic scan showed severe subarachnoid hemorrhage (SAH), especially in the posterior fossa with ventricular reflux, and vertebral angiography disclosed a fusiform dilatation with proximal narrowing of the left vertebral artery and narrowing in the midportion of the basilar artery. Continuous ventricular drainage was performed, but the patient died from rebleeding on the 14th hospital day. Autopsy revealed massive SAH around the brain stem and a fusiform aneurysm of the left vertebral artery. Microscopic examination demonstrated a local thickening of the wall with tearing of the intima and the media. A hematoma between the media and the adventitia communicated with the true lumen of the artery. The muscular layer was replaced by myxomatous connective tissue. The basilar artery had mild fibrous thickening of the intima and duplication of the internal elastica. The medial mucoid degeneration was discovered by iron-colloid stain in the intracranial arteries, especially in the vertebro-basilar system. However, arteriosclerotic change was minimal. The authors emphasize that SAH as initial symptom and hypertension as predisposition occur more frequently in vertebro-basilar dissecting aneurysms than previously described.