Ondine's curse in association with diabetes insipidus following transient vertebrobasilar ischemia.

Ischemic lesions of the brainstem can lead to complex neurologic deficits. Failure of the automatic control of ventilation (Ondine's curse syndrome) is a possible but rare syndrome following localized brainstem dysfunction. We report on a 49-year-old man with intermittent bradycardia, cranial nerves' dysfunctions and a slight right-sided hemiparesis. An acute brainstem ischemia was diagnosed and treated immediately with high-dose heparin. Cerebral angiography revealed a proximal occlusion of the left vertebral artery but a normal right vertebral artery and a hyperplastic right posterior inferior cerebellar artery. Cranial Computed Tomography and MRI scan demonstrated multiple ischemic lesions in the posterior circulation. During a 4-week treatment course the patient underwent six episodes of acute severe hypoxia and hypercapnia requiring orotracheal intubation twice and manual ventilation by air mask over a few minutes for four times after a tracheostomy had been performed. Twice a short-term episode of hypothalamic Diabetes insipidus was observed following hypoventilation. We conclude that both Ondine's curse syndrome and diabetes insipidus were due to transient vertebrobasilar ischemia.     

Rotational vertebral artery syndrome

Whether the rotational vertebral artery syndrome (RVAS), consisting of attacks of vertigo, nystagmus and tinnitus elicited by head-rotation induced compression of the dominant vertebral artery (VA), reflects ischemic dysfunction of uni- or bilateral peripheral or central vestibular structures, is still debated. We report on a patient with bilateral high-grade carotid stenoses, in whom rightward headrotation led to RVAS symptoms including a prominent nystagmus. Three-dimensional kinematic analysis of the nystagmus pattern, recorded with search coils, revealed major downbeat nystagmus with minor horizontal and torsional components. Magnetic resonance angiography demonstrated a hypoplastic right VA terminating in the posterior inferior cerebellar artery, a dominant left VA, and a hypoplastic P1-segment of the left posterior cerebral artery (PCA) that was supplied by the left posterior communicating artery (PCoA). The right PCA and both anterior inferior cerebellar arteries were supplied by the basilar artery. The right PCoA originated from the right internal carotid artery. Color duplex sonography showed severe reduction of diastolic blood flow velocities in the left VA during RVAS attacks. The nystagmus pattern can be best explained by vectorial addition of 3D sensitivity vectors of stimulated right and left anterior and horizontal semicircular canals with slightly stronger stimulation on the left side. We hypothesize that in RVAS, compression of dominant VA leads to acute vertebrobasilar insufficiency with bilateral, but asymmetric ischemia of the superior labyrinth. With regard to RVAS etiology, our case illustrates a type of pure vascular RVAS. Severity of attacks markedly decreased after successful bilateral carotid endarterectomy.     

椎-基底动脉夹层的临床特点

目的 分析椎-基底动脉夹层所致后循环缺血的临床特点。方法 对7例经磁共振血管造影（MRA）或全脑数字减影血管造影（DSA）证实的椎-基底动脉夹层患者的临床资料进行分析。结果 7例患者均表现为后循环缺血症状。其中1例患者经MRA诊断为椎动脉夹层，1例患者为尸检后确诊为椎-基底动脉夹层，另5例患者经DSA诊断。1例患者进行尿激酶溶栓治疗，3例进行抗血小板聚集治疗，3例进行支架成形术合并抗血小板聚集治疗。除1例溶栓治疗的患者死亡外，其余6例患者随访3～24个月均未发生缺血性卒中。结论 椎-基底动脉夹层是引起后循环缺血的原因之一，正确识别椎-基底动脉夹层对于患者预后至关重要。抗血小板聚集治疗和血管内治疗可能为椎-基底动脉夹层的有效治疗方法。     

支架成形术治疗后循环缺血86例疗效观察

目的 评价支架成形术治疗因大血管病变引起的后循环缺血的疗效及安全性。方法 回顾分析我科2003年3月以来开展的支架成形术治疗因大血管病变引起的后循环缺血患者的疗效及随访结果。86例患者进入研究,其中男性58例,女性28例,平均年龄61±5岁。结果 86例患者中2例为左椎动脉V3段夹层动脉瘤所致,1例为左椎动脉开口处夹层所致的狭窄,其余83例患者为动脉粥样硬化血管狭窄所致;2例手术失败,手术成功率97.7％。平均随访22.5±10.5个月。随访期间发生前循环脑梗死4例;后循环脑梗死3例,TIA2例,后循环缺血性卒中发生率为5.95%;脑出血2例。随访期间死亡3例,占3.57%。结论 支架成形术可有效治疗椎-基底动脉狭窄与夹层动脉瘤,预防缺血性脑血管疾病的发生。     

Bilateral Superior Cerebellar Artery Infarction after Stent-Angioplasty for Internal Carotid Artery Stenosis

Spontaneous bilateral cerebellar infarction in the territory of the superior cerebellar arteries is extremely rare. Occasionally there have been reports of bilateral cerebellar infarction due to vertebrobasilar atherosclerotic occlusion or stenosis, whereas no report of bilateral cerebellar infarction due to complicated hemodynamic changes. In this report, we present a patient with bilateral cerebral infarctions related to stenoses of bilateral internal carotid arteries, in whom vertebrobasilar system was supplied by multiple collaterals from both posterior communicating arteries and right external carotid artery. We performed stent-angioplasty of bilateral internal cerebral arterial stenosis, and then acute infarction developed on bilateral superior cerebellar artery territories. The authors assumed that the infarction occurred due to hemodynamic change between internal carotid artery and external carotid artery after stent-angioplasty for stenosis of right internal carotid artery.     

A case of severe stenosis of bilateral distal vertebral artery successfully treated with anastomosis operation]

A 65-year-old male complained of loss of consciousness for several minutes, transient diplopia and dizziness. He had no neurological deficits nor abnormalities in MR imaging. However, flow velocity of bilateral vertebral artery on ultrasonography indicated severe stenosis of bilateral distal vertebral artery. Brain angiography revealed severe stenosis of bilateral distal vertebral artery as well as occlusion of right middle cerebral artery (MCA). Single photon emission CT (SPECT: ECD-RVR method with acetazolamide loading) showed decreased cerebral blood flow and poor perfusion reserve in bilateral cerebellar hemisphere and right MCA territory. Superficial temporal artery-superior cerebellar artery (STA-SCA) anastomosis was performed. The patient turned out to have no episodes of unconsciousness attack, transient diplopia and dizziness after operation. Cerebral blood flow (CBF) in the posterior circulation was also improved. Evaluating quantitative CBF measurement by means of ECD-RVR method was useful for evaluating CBF. In cases who have severe stenosis of bilateral distal vertebral artery with complaints of vertebrobasilar insufficiency, STA-SCA anastomosis may be one of the most effective treatments.     

Cerebral autoregulation in middle cerebral artery territory precedes that of posterior cerebral artery in human cortex.

OBJECTIVE: Cerebral autoregulation tends to compensate changes in arterial blood pressure. This mechanism of cerebral blood flow regulation appears to be insufficient in orthostatic dysregulation in which mainly vertebrobasilar symptoms occur. To investigate this hypothesis, we compared cerebral autoregulation in the vascular territory of the carotic and vertebrobasilar vessel system using a leg cuff test to induce a drop in cerebral perfusion pressure. METHODS: We measured blood flow velocity in 10 healthy young volunteers (aged 26.7 +/- 0.3 years, 7 male) simultaneously in the middle and posterior cerebral artery with transcranial Doppler sonography. A leg cuff test was used to induce a sudden decrease in arterial blood pressure. Arterial blood pressure was measured with a non-invasive photoplethysmographic method. The averaged relative blood flow velocity changes due to the pressure step were compared between both vessel territories. RESULTS: After cuff release systolic (diastolic) blood flow velocity increased with a latency of 1.1 +/- 0.3 s (1.8 +/- 0.4 s). Due to a smaller decrease and identical time courses cerebral blood flow velocity recovery in the posterior cerebral artery precedes blood flow recovery in the middle cerebral artery by 0.9 +/- 0.3 s. DISCUSSION: Cerebral autoregulation in the carotid and vertebrobasilar system does not differ in the time course of the blood flow velocity recovery. Due to a smaller decrease in blood flow velocity recovery in the posterior cerebral artery precedes recovery in the middle cerebral artery by nearly 1 s.     

A Case of Posterior Circulation Embolism Due to a Subtype of Bow Hunter's Syndrome Diagnosed by Non-Invasive Examination

Bow hunter's syndrome is the mechanical compression of the vertebral artery due to cervical rotation, resulting in ischemic symptoms in the vertebrobasilar artery territory. However, some cases present without typical symptoms and exhibit compression of the non-dominant side of the vertebral artery. We encountered a case of posterior circulation embolism due to a subtype of bow hunter's syndrome in a 74-year-old man. Although the right vertebral artery was not visualized on time-of-flight magnetic resonance angiography in the neutral position, duplex ultrasonography and time-of-flight magnetic resonance angiography in the left cervical rotation position showed blood flow in the right vertebral artery. In this case, blood flow in the contralateral vertebral artery was normal, and typical bow hunter's syndrome symptoms did not occur. In a case of posterior circulation embolism with undetermined etiology, wherein the routine duplex ultrasonography and time-of-flight magnetic resonance angiography results were inconclusive, additional testing with head positioning led to the diagnosis of a subtype of bow hunter's syndrome.     

Microsurgical anatomy of the intracranial part of the vertebral artery

Abstract

We studied the intracranial portion of the vertebral artery and its branches in 11 cadaveric specimens. We evaluated the course of vessels and their dimensions (external diameter and length), as well as relationships between each of them. The vertebral artery was larger on the ? left side in two cases, on the right in five cases, and equal on both sides in four cases. The right and left vertebral arteries joined each other forming the basilar artery at the level of the pontomedullary junction in four cases, 2 mm below it in one case, and 1 to 7 mm above it in six cases. We divided all branches of the intracranial vertebral artery into two groups: the medial branches and the lateral branches. Two major types of medial branches were observed: the anterior spinal artery and the branches of the foramen caecum. The origin of the anterior spinal artery was located 6.5 mm (5-11 mm) proximal to vertebrobasilar junction on the right and 8.5 mm (6-17 mm) on the left. The anterior spinal artery was absent on the right in two cases and on the left in one. Branches arising from the vertebral artery to the foremen caecum were found in four brains. Lateral branches originated from the posterolateral or lateral aspect of vertebral artery. The posterior inferior cerebellar artery, the largest branch of the vertebral artery, was included in this group. Other branches were mostly located between the origin of the posterior inferior cerebellar artery and the vertebrobasilar junction. Forty-six lateral branches originating from the vertebral artery were found in 11 brains (26 on the right and 20 on the left). Lateral branches widely anastomosed with perforators from the basilar arteryposterior inferior cerebral artery; and the anterior inferior cerebellar artery. [Neurol Res 1994; 16:171–180]     

后循环缺血与椎-基底动脉病变的关系

目的探讨后循环缺血(PCI)与椎-基底动脉病变的关系。方法对57例PCI患者(PCI组)进行颅颈部动态增强磁共振血管成像(DCE-MRA)检查,并与同期住院的非PCI脑卒中患者(NPCI组)进行比较。结果与NPCI组相比,PCI组椎-基底动脉异常率显著增高(50.7%vs 70.2%;P<0.05),病变多在椎动脉起始部和颅内段;椎-基底动脉多发性病变的发生率显著增高(P<0.05);椎动脉一侧优势、椎动脉颈段、基底动脉及前循环病变情况与NPCI组比较差异无统计学意义。结论PCI患者最常见的血管病变部位为椎动脉起始部和颅内段,并且椎-基底动脉病变呈多发性。     

Imaging of the intracranial vertebrobasilar system using color-coded ultrasound.

BACKGROUND: Anatomic variety and difficult accessibility of the vertebrobasilar arteries pose considerable problems to conventional ultrasound. We evaluated the diagnostic potential of transcranial color-coded sonography in the distal part of this system. METHODS: We insonated the intracranial section of the vertebrobasilar arteries through the foramen magnum window in 24 healthy individuals using a Doppler color flow imaging system in connection with a 2.5-MHz sector transducer. Magnetic resonance images in special inclination planes were performed and compared with the color-coded duplex images in five cases. RESULTS: The B-mode image of the craniocervical junction and the intracranial parenchymal structures in addition to the color-coded blood flow allowed an unambiguous identification of the vertebrobasilar arteries (vertebral artery, 96%; basilar artery, 79%; and posterior inferior cerebellar artery, 50%). Blood flow velocities were measured considering the insonation angles: vertebral arteries, 50/24 cm/sec (30 degrees); basilar artery, 59/28 cm/sec (4 degrees); and posterior inferior cerebellar artery, 56/30 cm/sec (20 degrees) [peak systolic/end diastolic blood flow velocity (mean angle correction)]. CONCLUSIONS: Transcranial color-coded sonography enables accurate identification and differentiation of the intracranial vertebrobasilar arteries and improves accuracy of Doppler measurements. It may prove useful for evaluation of tortuosity and for hemodynamic studies in this vascular territory.     

Study on the vertebro-basilar system in "moyamoya" disease

Posterior circulation in 82 children of "moyamoya" disease are studied. Two aspects of "moyamoya" disease, (ie; occlusive lesion of cerebral vessels and the development of abnormal vascular network as collateral channel,) are also detected in the vertebrobasilar system. Among 82 cases, 49 cases showed the occlusion of posterior cerebral artery at their quadrigeminal segment. Twenty-three showed the more proximal occlusive lesions. Vertebral artery occlusion were found in 3 cases. As the occlusive lesion progresses, abnormal vascular network at the posterior portion of skull base developed. This network consists mainly of thalamogeniculate artery, posterior choroidal artery, and also of other thalamoperforators. Visual field defect as an ischemic symptom of occipital lobe was detected in 9 cases (11%). Superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis (temporal muscle graft), which were not considered to be so effective to the ischemia of the posterior circulation, were shown to exert indirect redistribution effect upon the vertebrobasilar system. However, this effect is such an indirect one that these surgical treatments cannot prevent the occurrence of ischemic stroke in the vertebrobasilar system. For this purpose, omentum transplantation to the occipital lobe may be needed as a method of direct revascularization.     

Persistent primitive trigeminal artery presenting with Weber's syndrome: report of a case with three-dimensional CT angiographic evaluations]

We report a rare case of persistent primitive trigeminal artery(PPTA) presenting with brain stem infarction known as Weber's syndrome, and document its unique findings of three-dimensional CT angiography(3 D-CTA). A 69-year-old woman was admitted to our hospital because of gait disturbance and blepharoptosis on the right eye. Neurological examination on admission revealed the right oculomotor nerve palsy, left hemiparesis and dysarthria, all of which indicated the signs and symptoms of Weber's syndrome. Initial CT scan revealed no abnormality, but a subsequent 3 D-CTA demonstrated the PPTA originating from the right internal carotid artery penetrate into the clivus directly to the distal basilar artery, on top of which a small saccular aneurysm was incidentally visualized. Right internal carotid angiograms showed the PPTA run between the cavernous segment of the internal carotid artery and the distal portion of the basilar artery with the filling of both the posterior cerebral and superior cerebellar arteries. However, the proximal portion of the basilar artery was visualized through the right vertebral artery and there was no blood flow to its distal portion. Evidence of infarction was finally confirmed at the right midbrain and thalamus by the MRI performed 5 days after the onset. With a conservative treatment including physical therapy, the patient recovered well from the deficits and could walk by herself with a cane. With regard to the pathogenesis of vertebrobasilar insufficiency in a patient with PPTA, it is generally considered that microembolus from an atherosclerotic carotid artery may be its cause because of the presence of direct communication between the anterior and posterior circulations. In the present case, however, this mechanism may not be applied since there was no evidence of atherosclerotic plaque or stenotic lesions on the carotid arteries. Alternatively, an embolic occlusion may have occurred in the paramedian branches of the posterior cerebral artery since a dilated PPTA itself, which resembled fusiform-aneurysm in appearance, may become the origin of microembolus.     

Rotational vertebrobasilar insufficiency due to dynamic compression of the dominant vertebral artery by the thyroid cartilage and occlusion of the contralateral vertebral artery at C1-2 level.

BACKGROUND: Vertebrobasilar insufficiency caused by head rotation is an uncommon event. The mechanism is obstruction of the vertebral artery resulting in flow limitation or, less frequently, thromboembolism. CASE DESCRIPTION: A 41-year-old male developed dizziness and light-headedness during chiropractic manipulation when his head was turned to the extreme right position. Computed tomography angiography (CTA) of the neck and selective digital subtraction angiography (DSA) of the vertebral arteries revealed that when the patient turned his head to the extreme right position the dominant right vertebral artery was compressed between the posterior aspect of the thyroid cartilage and anterior aspect of the right transverse process of C6 resulting in focal stenosis, while the left vertebral artery is severely compressed with significant flow limitation at the level of C1-2. Because the patient was healthy and asymptomatic, conservative management was adopted. At the 9-month follow-up visit the patient was asymptomatic and able to compensate for his problem avoiding turning his head to the extreme right position. CONCLUSIONS: We present an uncommon case of rotational vertebrobasilar insufficiency (VBI) where the dominant vertebral artery has an anomalous course compressed by the thyroid cartilage at C6 level, associated with contralateral vertebral artery rotational stenosis at C1-2. The patient was successfully managed conservatively.     

Provokable bilateral vertebral artery compression diagnosed with transcranial Doppler.

BACKGROUND: Head and neck movements may cause vascular compression that produces a syndrome of vertebrobasilar insufficiency. Vertebrobasilar circulation was examined noninvasively in two patients who were able to provoke these symptoms repeatedly on demand. CASE DESCRIPTIONS: Blood flow velocities in the basilar artery (case 1) and both posterior cerebral arteries (both cases) were measured continuously by transcranial Doppler sonography while the patients voluntarily performed the offending maneuvers and reproduced their symptoms. The provocative maneuvers evoked an immediate and precipitous drop in blood flow velocity, producing symptoms within seconds. Upon relief, the blood flow velocities showed a transient overshoot before returning to baseline values. CONCLUSIONS: These observations indicate that the symptoms of vertebrobasilar insufficiency were due to real reductions in blood flow and demonstrate the usefulness of transcranial Doppler sonography to diagnose bilateral extracranial vertebral artery compression.     

Posterior circulation ischemia in patients with fetal-type circle of Willis and hypoplastic vertebrobasilar system

Little attention has been given to the fetal-type posterior circle of Willis (FTP) in the literature; also symptomatic basilar artery (BA) hypoplasia has been rarely reported. We aimed to illustrate that the association of a hypoplastic vertebrobasilar system (VBS) with the FTP may lead to posterior circulation ischemia. Magnetic resonance imaging and three-dimensional time-of-flight magnetic resonance angiography were performed in 88 consecutive patients with ischemic stroke or TIA in the VBS. Thirteen patients were identified with either stroke or TIA in the context of a hypoplastic VBS and a fetal origin of the posterior cerebral arteries. All patients had unilateral or bilateral FTP, hypoplastic BA and at least one hypoplastic vertebral artery. Transcranial color-coded duplex revealed decreased flow velocity and increased pulsatility index along the BA. A hypoplastic VBS may be accompanied by the FTP and its simultaneous occurrence can predispose to ischemic events in the posterior circulation.     

症状性椎基底动脉狭窄的血管内治疗(附95例报告)

目的 总结椎基底动脉系统症状性血管狭窄的血管内治疗的策略、方法 、术中风险及术后疗效.方法 回顾性分析2004年1月至2008年7月治疗的95例采用支架置入治疗的症状性椎基底动脉狭窄患者的临床资料.结果 采用支架置入治疗的患者中,椎动脉起始部狭窄者21例,椎动脉颈段狭窄者3例,椎动脉颅内段狭窄者16例,椎基底动脉交界处狭窄者15例,基底动脉段狭窄者36例,大脑后动脉P2段狭窄者4例.所有狭窄均>50%.手术的技术成功率为97%(92/95).术后平均狭窄率从76.1%(50%～95%)下降到9.2%(0～20%).所有患者均在术后6个月-2年内随访,其中88例患者效果良好.结论 脑血管狭窄处支架置入术是目前治疗该类疾病的有效方法 ,其长期疗效还有待进一步观察.     

Vertebrobasilar insufficiency revealed by xenon-133 inhalation SPECT

A study of cerebral and cerebellar blood flow reactivity to acetazolamide by xenon-133-inhalation single photon emission computed tomography (133Xe SPECT) was carried out in a patient with bouts of transient basilar ischemia, whose neurological examination, computed tomographic scan, and auditory evoked potentials were normal. Though the patient was symptom-free at the time of the study, 133Xe SPECT demonstrated vertebrobasilar insufficiency by showing an impaired vasodilatory response in both the occipital lobes and the right cerebellar hemisphere. Three weeks later, the patient suffered an extensive stroke in these same areas. We therefore suggest that this method could be of great value in the assessment of vertebrobasilar insufficiency.     

Infarcts presenting with a combination of medial medullary and posterior inferior cerebellar artery syndromes

Cerebellar and medial medullary infarctions are well-known vertebrobasilar stroke syndromes. However, their development in a patient with distal vertebral artery occlusion has not been previously reported. A 49-year-old man with longstanding hypertension suddenly developed vertigo, right-sided Horner syndrome, and left-sided weakness. An MRI of the brain showed acute infarcts in the right inferior cerebellum (posterior inferior cerebellar artery territory) and the right upper medial medulla (direct penetrating branches of vertebral artery). Magnetic resonance angiogram showed occlusion of the distal vertebral artery on the right side. Atherothrombotic occlusion of the distal vertebral artery may cause this unusual combination of vertebrobasilar stroke.     

Reference values for vertebral artery flow volume by duplex sonography in young and elderly adults

BACKGROUND AND PURPOSE: Vertebrobasilar ischemia has been attributed to a reduction of net vertebral artery flow volume, the product of mean flow velocity and the cross-sectional area of the vessel. It can be determined by duplex sonography. There are no reference values for vertebral artery flow volume in an age group representative of patients with cerebrovascular disease. METHODS: We examined 50 nonvascular neurological patients (age 55.8+/-14.0 years). Flow velocities and vessel diameters were recorded in the intertransverse (V2) segments bilaterally, and the flow volume was calculated according to the following equations: (1) Q1=time-averaged mean velocity times area and (2) Q2=(time-averaged maximum velocity/2)times area. RESULTS: Flow velocities and vessel diameters tended to be lower on the right side, resulting in a lower flow volume. Flow volumes (according to Equation 1) were 77.2+/-29.8 mL/min on the right side, 105.3+/-46.4 mL/min on the left side, and 182.0+/-56.0 mL/min net. Side-to-side differences were not significant. Flow volumes calculated with the 2 equations did not differ significantly. An age dependence could not be shown, but vessel diameters and net vertebral artery flow volumes were significantly lower in women than in men. The normal range for net vertebral artery flow volume defined by the 5th to 95th percentiles is between 102.4 and 301.0 mL/min. This wide range is due to the high interindividual variability of the parameters. CONCLUSIONS: On the basis of the reference values presented here, the association of decreased vertebral artery flow volume and vertebrobasilar ischemia should be reevaluated. Additional areas for investigation include the quantification of collateral flow in the vertebral arteries in carotid artery occlusive disease and their contribution to overall cerebral blood flow volume.