Posterior cerebral artery involvement in moyamoya disease: initial infarction and angle between PCA and basilar artery

Purpose

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease, and progressive involvement of the posterior cerebral artery (PCA) has been reported. However, majority of MMD articles are presenting classic anterior circulation related issues. This study investigates the preoperative factors related to the long-term outcome of posterior circulation in MMD.

Methods

Retrospective review of 88 MMD patients (166 PCAs in either hemisphere) without symptomatic disease involvement of PCA at initial diagnosis was done. Data at initial diagnosis regarding age, presence of infarction, status of the PCA, type of posterior communicating artery, and the angle between PCA and basilar artery were reviewed. Progressive stenosis of PCA was evaluated by symptom or radiological imaging during follow up.

Results

During an average follow up of 8.3 years, 29 out of 166 (18 %) evaluated PCAs showed progressive disease involvement. The average time of progression from the initial operation was 4.9 years, with the latest onset at 10.8 years. The patients who showed progressive stenosis of the PCA tended to be younger, present with infarction, have smaller angle between PCA and basilar artery, and have asymptomatic stenosis of the PCA at initial presentation. However, multivariate analysis confirmed only the presence of initial infarction and a smaller angle between PCA and basilar artery to be significantly associated with progressive stenosis of PCA.

Conclusions

Involvement of PCA in MMD may occur in a delayed fashion, years after the completion of revascularization of anterior circulation. Persistent long-term follow-up regarding the posterior circulation is recommended.     

Cognitive Decline and Hypersomnolence: Thalamic Manifestations of a Tentorial Dural Arteriovenous Fistula (dAVF)

Background

Intracranial dural arteriovenous fistulas (dAVFs) often present with pulsatile tinnitus, orbital congestion, and headache. Occasionally, they present with focal neurologic deficits, a dementia-like syndrome, hemorrhage, or ischemic infarction.

Methods

This study is based on the case of a 71-year-old gentleman who presented with 6 months of progressive forgetfulness, inattention, and hypersomnolence. Four weeks prior to presentation, he developed symptoms of left-sided pain, numbness, and worsening weakness. Neurologic examination demonstrated hypersomnolence, a score of 30/38 on the Kokmen Short Test of Mental Status, and left hemiparesis. MRI brain revealed bilateral thalamic T2 hyperintensities with associated enhancement. MR venogram (MRV) showed a vascular malformation in the posterior fossa and occlusion of the straight sinus. Conventional cerebral angiogram confirmed a tentorial dAVF. The dAVF was definitively treated with transarterial embolization, followed by clip ligation of the arterialized draining vein. Twelve weeks later, there was clinical resolution of left hemiparesis and improvement in cognitive status. MRI revealed complete resolution of the thalamic hyperintensities. MRV demonstrated recanalization of the straight sinus.

Results

Intracranial dAVFs are uncommon but potentially life-threatening acquired vascular malformations. The initiating factor is venous hypertension, causing retrograde flow, venous congestion, ischemia, and sometimes infarction. The spectrum of clinical manifestations in dAVFs reflects the degree of venous congestion present. If retrograde venous flow is surgically obliterated, then venous hypertension may be reversible. Bilateral thalamic venous congestion can present as a thalamic dementia.

Conclusion

We conclude that intracranial dAVFs with thalamic venous congestion should be considered in the diagnostic differential for patients who present with subacute cognitive decline and T2 hyperintense thalamic signal change.     

Arteriovenous Malformation with an Occlusive Feeding Artery Coexisting with Unilateral Moyamoya Disease

Background

Arteriovenous malformations (AVMs) with vascular abnormalities, including aneurysms, have been reported frequently. However, the coexistence of AVM and unilateral moyamoya disease is rare. We report herein an AVM patient who presented with acute ischemic stroke with unilateral moyamoya disease and occlusion of the feeding artery.

Case Report

A-41-year old man was admitted with sudden dysarthria and facial palsy. Brain computed tomography and magnetic resonance imaging revealed an acute infarction adjacent to a large AVM in the right frontal lobe. Cerebral angiography revealed occlusions of the proximal right middle cerebral and proximal anterior cerebral arteries, which were the main feeders of the AVM. Innumerable telangiectatic moyamoya-type vessels between branches of the anterior cerebral artery and dilated lenticulostriate arteries on the occluded middle cerebral artery were detected. However, a nidus of the AVM was still opacified through the distal right callosomarginal artery, which was supplied by the remaining anterior cerebral artery and leptomeningeal collaterals from the posterior cerebral artery.

Conclusions

While AVM accompanied by unilateral moyamoya disease is rare, our case suggests an association between these two dissimilar vascular diseases.     

Thalamic tumors in children

Introduction

Thalamic tumors are rare tumors which are usually diagnosed in the pediatric age group. Although recent developments in neurosurgical practice allow more radical treatments, information about outcome is scarce for these deep-seated challenging tumors.

Methods

Medical records of 45 pediatric patients who presented with thalamic tumors between 1999 and 2012 were reviewed.

Discussion

Prognostic implication of tumor characteristics and patient variables are discussed. Although challenging, recent innovations in the field of neurosurgery and refinements in technique may prolong survival in some cases.     

Hypoplastic vertebral artery: frequency and associations with ischaemic stroke territory

Background

In patients with posterior inferior cerebellar artery infarction (PICAI) or lateral medullary infarction (LMI), the ipsilateral vertebral artery is often hypoplastic and therefore at an increased risk of ischaemic stroke.

Objective

To investigate the frequency and clinical relevance of hypoplastic vertebral artery (HVA) in patients with ischaemic stroke with or without vertebral artery territory and in normal healthy people.

Methods

529 patients with ischaemic stroke, including vertebral artery territory infarction (LMI or PICAI), were classified according to their stroke location (303 anterior circulation strokes (ACS) and 226 posterior circulation strokes (PCS)) by MRI. The frequency of HVA, defined as a diameter of ⩽2 mm by magnetic resonance angiography, was measured in comparison with 306 normal healthy people.

Results

185 patients (35.2%) from the cohort had HVA (3.4%, bilaterally). Patients with PCS showed a higher rate of HVA than those with ACS (45.6% vs 27.1%, p<0.001). The HVA frequency of those with ACS was similar to that of the normal group (26.5%). Of the 112 patients with vertebral artery territory stroke, 58 (51.8%) had HVA (bilateral HVA in 10), and all of 48 showed ipsilateral HVA territory stroke. In 102 patients with vertebral artery territory stroke, classification of the ipsilateral vertebral artery as hypoplastic (vs dominant or symmetric) tended to predict the involvement of multiple and extensive lesions, and a higher incidence of steno‐occlusion (p<0.001).

Conclusion

HVA is not rare in the normal population, and is frequent in patients with PCS. People with HVA may have a high probability of PCS, with atherosclerotic susceptibility and ipsilateral lesions in the vertebral artery territory.Congenital variations in the arrangement and size of the vertebral arteries are frequently recognised, ranging from asymmetry of both vertebral arteries to severe hypoplasia of one vertebral artery on cerebral angiography. In a pathoanatomical study, hypoplastic vertebral artery (HVA) was defined as a lumen diameter of ⩽2 mm,¹ but there is no consensus on this value.The absence of vertebrobasilar insufficiency symptoms among people with HVA indicates that even marked vertebral artery asymmetry is a normal variation,^2,3,4 and has led to an underestimation of the incidence and clinical relevance of HVA. However, ipsilateral HVA is common in patients with posterior inferior cerebellar artery infarction (PICAI) or lateral medullary infarction (LMI), suggesting that HVA confers an increased probability of ischaemic stroke. Although the relationship between hypoplasia of the vertebral artery or the basilar artery and the risk of posterior circulation ischaemia has been examined,⁵ there have been few reports on the relationship between HVA and territorial ischaemic stroke, to our knowledge.The objectives of this study were to determine the frequency of HVA in normal healthy people and in patients with stroke, and the clinical relevance of HVA in patients with ischaemic stroke with vertebral artery territory.     

Intra-arterial Dantrolene for Refractory Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Background

Intravenous dantrolene has been used to prevent and treat cerebral vasospasm. We report a case of refractory cerebral vasospasm treated with intra-arterial dantrolene after aneurysmal subarachnoid hemorrhage.

Methods

A 56-year-old woman suffered a diffuse subarachnoid hemorrhage from a ruptured anterior communicating artery aneurysm which was successfully treated with coil embolization. She subsequently developed bilateral severe angiographic vasospasm which was treated with intra-arterial vasodilators. However, owing to the recurrence of vasospasm, intra-arterial dantrolene followed by balloon angioplasty was used.

Results

There was moderate improvement of the severe vasospasm in bilateral A1 segments of the anterior cerebral arteries after microcatheter-based intra-arterial infusion of 30?ml (1?mg/ml) dantrolene. Patient??s hemodynamic parameters were monitored during and after the procedure and no significant changes were seen after dantrolene infusion. A follow up cerebral angiogram after 1?day demonstrated the persistence of therapeutic effect.

Conclusion

Intra-arterial dantrolene induced a sustained improvement in cerebral vasospasm secondary to ruptured aneurysm. No significant side effects were observed during or after the infusion of the drug.     

Bedside Diagnosis of Mitochondrial Dysfunction After Malignant Middle Cerebral Artery Infarction

Background

The study explores whether the cerebral biochemical pattern in patients treated with hemicraniectomy after large middle cerebral artery infarcts reflects ongoing ischemia or non-ischemic mitochondrial dysfunction.

Methods

The study includes 44 patients treated with decompressive hemicraniectomy (DCH) due to malignant middle cerebral artery infarctions. Chemical variables related to energy metabolism obtained by microdialysis were analyzed in the infarcted tissue and in the contralateral hemisphere from the time of DCH until 96 h after DCH.

Results

Reperfusion of the infarcted tissue was documented in a previous report. Cerebral lactate/pyruvate ratio (L/P) and lactate were significantly elevated in the infarcted tissue compared to the non-infarcted hemisphere (p < 0.05). From 12 to 96 h after DCH the pyruvate level was significantly higher in the infarcted tissue than in the non-infarcted hemisphere (p < 0.05).

Conclusion

After a prolonged period of ischemia and subsequent reperfusion, cerebral tissue shows signs of protracted mitochondrial dysfunction, characterized by a marked increase in cerebral lactate level with a normal or increased cerebral pyruvate level resulting in an increased LP-ratio. This biochemical pattern contrasts to cerebral ischemia, which is characterized by a marked decrease in cerebral pyruvate. The study supports the hypothesis that it is possible to diagnose cerebral mitochondrial dysfunction and to separate it from cerebral ischemia by microdialysis and bed-side biochemical analysis.     

Percheron动脉梗死临床分析

Percheron动脉（AOP）是丘脑旁正中动脉的一种解剖变异形式,随着影像技术的发展,AOP受到越来越多的关注。现报道1例AOP闭塞所致双侧丘脑梗死的病例,其特点是双侧丘脑梗死呈进展性,但早期弥散加权成像未随卒中进展而出现相应弥散受限信号,多次复查后方出现与症状相符的影像学表现。通过本例患者并回顾相关文献资料,探讨AOP梗死可能的发病机制、临床表现和影像学特征,以期提高对此类疾病的诊治水平。     

Multiple encephalogaleoperiosteal synangiosis for bilateral carotid artery stenosis in a 13-year-old girl: a case report

Introduction

Encephalogaleoperiosteal synangiosis (EGS) has been widely used to treat children with moyamoya disease (MMD). We present the first case of successful multiple EGS in a patient with brain ischemic disease who presented with different cerebrovascular findings from MMD.

Methods

A 13-year-old girl had an increased frequency of transient ischemic attacks that affected her right extremities. Digital subtraction angiography showed tapering of the internal carotid artery (ICA). The anterior cerebral artery (ACA) and middle cerebral artery (MCA) were visible on vertebral angiogram, but not on carotid angiogram. The intact circle of Willis and lack of hypervascularity of the lenticulostriate arteries were observed. Decreased regional cerebral blood flow (CBF) in the bilateral ACA and MCA territories quantified by ¹²³I-N-isopropyl-p-iodoamphetamine-single photon emission computed tomography indicated the need for extracranial-intracranial bypass surgery. Multiple EGS procedures were performed instead of direct anastomosis, which is the standard procedure for intracranial ICA stenosis, because the space for the craniotomy was limited by transdural anastomosis.

Results

Despite the fact that the diagnosis of MMD was questionable, the hemispheres were well vascularized, and the neurology and CBF improved postoperatively.

Conclusion

The preserved circle of Willis and lack of moyamoya vessels were inconsistent with the features of MMD. However, childhood onset, bilateralness, chronic intracranial ICA stenosis, and transdural anastomosis indicated the same underling pathogenicity as MMD. It is hypothesized that ICA stenosis occurred immediately proximal to the posterior communicating artery in this case. This would have produced the atypical finding of the remaining circle of Willis without growth of the basal moyamoya vessels.

     

Second-order projection from the posterior lateral line in the early zebrafish brain

Background

Mechanosensory information gathered by hair cells of the fish lateral-line system is collected by sensory neurons and sent to the ipsilateral hindbrain. The information is then conveyed to other brain structures through a second-order projection. In the adult, part of the second-order projection extends to the contralateral hindbrain, while another part connects to a midbrain structure, the torus semicircularis.

Results

In this paper we examine the second-order projection from the posterior lateral-line system in late embryonic/early larval zebrafish. At four days after fertilization the synaptic field of the sensory neurons can be accurately targeted, allowing a very reproducible labeling of second-order neurons. We show that second-order projections are highly stereotyped, that they vary according to rhombomeric identity, and that they are almost completely lateralized. We also show that the projections extend not only to the contralateral hindbrain and torus semicircularis but to many other brain centers as well, including gaze- and posture-controlling nuclei in the midbrain, and presumptive thalamic nuclei.

Conclusion

We propose that the extensive connectivity observed in early brain development reveals a basic scaffold common to most vertebrates, from which different subsets are later reinforced in various vertebrate groups. The large repertoire of projection targets provides a promising system to study the genetic encoding of this differential projection capacity.     

Pediatric thalamic tumors in the MRI era: a Canadian perspective

Background

Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system.

Methods

We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989–2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed.

Results

Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53 % of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61?±?13 % for unithalamic tumors compared to 37?±?32 % for bithalamic tumors (p?=?0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive.

Conclusion

Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

     

Medial posterior choroidal artery territory infarction associated with tumor removal in the pineal/tectum/thalamus region through the occipital transtentorial approach

Object

Damage to the deep venous system, occipital lobe, and/or corpus callosum is well known to cause complications associated with the occipital transtentorial approach (OTA), but ischemic complications are not well documented. The authors investigated the high incidences of ischemic complications associated with removal of pineal/tectal/thalamic tumors through the OTA.

Methods

Clinical records of 29 patients who underwent 31 surgeries using the OTA from December 2001 to May 2011 were retrospectively studied. Tumor locations were the pineal/tectal/thalamic region for 19, cerebellum for 7, and medial temporal lobe for 3.

Results

Postoperative diffusion-weighted magnetic resonance images obtained within 72 h after surgery detected infarction in the tectal/splenial/thalamic region, presumably representing the medial posterior choroidal artery (MPChA) territory, in 10 patients. All these patients had tumor in the pineal/tectal/thalamic region. Deteriorated or newly developed eye symptoms including vertical gaze palsy tended to persist in these patients compared to those without ischemic complications.

Conclusions

A relatively high incidence of MPChA territory infarction was associated with removal of tumors in the pineal/tectal/thalamic region through the OTA. Eye symptoms often occurred post-surgery and tended to persist in these patients. Neurosurgeons must be aware of the possibility of MPChA territory infarction to further increase the safety of the OTA.     

Acute Ischemic Injury on Diffusion-Weighted Magnetic Resonance Imaging after Poor Grade Subarachnoid Hemorrhage

Background

Poor clinical condition is the most important predictor of neurological outcome and mortality after subarachnoid hemorrhage (SAH). Rupture of an intracranial aneurysm was shown to be associated with acute ischemic brain injury in poor grade patients in autopsy studies and small magnetic resonance imaging series.

Methods

We performed diffusion-weighted magnetic resonance imaging (DWI) within 96 h of onset in 21 SAH patients with Hunt–Hess grade 4 or 5 enrolled in the Columbia University SAH Outcomes Project between July 2004 and February 2007. We analyzed demographic, radiological, clinical data, and 3 months outcome.

Results

Of the 21 patients 13 were Hunt–Hess grade 5, and eight were grade 4. Eighteen patients (86%) displayed bilateral and symmetric abnormalities on DWI, but not on computed tomography (CT). Involved regions included both anterior cerebral artery territories (16 patients), and less often the thalamus and basal ganglia (4 patients), middle (6 patients) or posterior cerebral artery territories (2 patients), or cerebellum (2 patients). At 1-year, 15 patients were dead (life support had been withdrawn in 6), 2 were moderately to severely disabled (modified Rankin Scale [mRS] = 4–5), and 4 had moderate-to-no disability (mRS = 1–3).

Conclusions

Admission DWI demonstrates multifocal areas of acute ischemic injury in poor grade SAH patients. These ischemic lesions may be related to transient intracranial circulatory arrest, acute vasoconstriction, microcirculatory disturbances, or decreased cerebral perfusion from neurogenic cardiac dysfunction. Ischemic brain injury in poor grade SAH may be a feasible target for acute resuscitation strategies.     

A modified method to enhance the safety of endoscopic third ventriculostomy (ETV)—transendoscopic pulse-waved microvascular Doppler-assisted ETV,technical note

Introduction

Endoscopic third ventriculostomy (ETV) is a simplified treatment relative to shunting for several types of hydrocephalus. The fatal complication of ETV is intraoperative hemorrhage due to arterial injury of the basilar artery, posterior cerebral arteries, and their perforators.

Material and methods

Here, we present a modified technique of ETV by using a transendoscopic pulse-waved microvascular Doppler probe and videoscope head to avoid vascular injury behind the tuber cinereum (TC). The microvascular Doppler probe can detect the basilar artery complex through the TC.

Conclusion

Ventriculostomy with the probe head helps prevent vascular injury by informing the presence of invisible vessels under endoscopic view during perforation, and the method introduced here is certain to prove invaluable for enhancing the safety of ETV.     

Angiographic features help predict outcome after stereotactic radiosurgery for the treatment of pediatric arteriovenous malformations

Purpose

Arteriovenous malformations (AVMs) are a frequent cause of hemorrhagic stroke in children. Stereotactic radiosurgery (SRS) is an established treatment for these lesions, particularly those that are surgically inaccessible. Because only complete AVM obliteration is believed to protect against the future risk of hemorrhage, identifying lesion characteristics that predict response to therapy is an important objective. The goal of this study is to evaluate the influence of angiographic features of AVMs on the rate of obliteration following treatment with SRS.

Methods

This is a retrospective cohort study of pediatric patients (age ≤18 years) treated with Gamma Knife SRS for cerebral AVMs between 2000 and 2012. Detailed angiographic data at the time of initial angiographic evaluation were prospectively recorded by experienced neurointerventional radiologists. The primary outcome was the rate of obliteration on a 3-year follow-up angiogram.

Results

We identified 42 pediatric patients treated with SRS for cerebral AVMs. Twenty-seven patients completed 3-year angiographic follow-ups. Complete obliteration was seen in 30 %, partial response in 67 %, and no response in 4 %. Higher SRS dose was associated with complete obliteration. Larger AVM diameter, presence of multiple draining veins, and presence of multiple draining veins reaching a sinus were associated with partial response. In this small cohort, diffuse AVM borders, presence of aneurysm, and pre-SRS embolization were not associated with obliteration.

Conclusions

Our study identifies AVMs in the pediatric population with a nidus diameter of <2.5 cm and a solitary draining vein as the most likely to undergo complete obliteration after SRS treatment.     

Arterial vascularization of the pineal gland

Purpose

The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG.

Methods

Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated.

Results

The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature.

Conclusions

This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults.     

Symptomatic Cerebral Vasospasm Following Resection of a Medulloblastoma in a Child

Background

Vasospasm may occur following intracranial tumor resection but is uncommon following resection of tumors in the posterior fossa.

Methods

Case report.

Results

Here, we report an unusual pediatric case of symptomatic cerebral vasospasm following resection of a posterior fossa medulloblastoma in a 10-year-old child. CT angiogram and serial Transcranial Doppler (TCD) studies confirmed the presence of vasospasm and response to hemodynamic augmentation therapy, resulting in favorable outcome.

Conclusion

This case illustrates an unusual complication of posterior fossa tumor resection, and the potential utility of TCD studies in the detection and management of vasospasm in pediatric neurocritical care.     

Diffuse Cerebral Intravascular Coagulation and Cerebral Infarction in Pneumococcal Meningitis

Background

There is a widely held belief that cerebral infarction after bacterial meningitis is always caused by vasculitis; however, evidence is weak. We hypothesized that diffuse cerebral intravascular coagulation is an additional explanation of cerebral infarction in patients with pneumococcal meningitis.

Methods

Sixteen brains of adults who died from pneumococcal meningitis were investigated. Clinical data were collected, and brain sections were scored for signs of inflammation and activation of coagulation. Patients with and without cerebral infarction on autopsy were compared.

Results

In total, 38% of patients had focal neurological deficits. Patients died at a median of 7 days (range, 0–32 days) after admission. On autopsy, the nine patients (56%) with cerebral infarctions more often had arterial thrombosis (p = 0.04) than patients without infarction. Patients with infarction tended to have more inflammatory infiltrations of brain parenchyma, microvascular proliferation, small vessel vasculitis/endarteritis obliterans, blood clotting/vessel clogging, and venous thrombosis. None of the patients had large vessel vasculitis. Five patients had cerebral infarctions without vasculitis or endarteritis obliterans. Although four patients with cerebral infarctions had small vessel vasculitis or endarteritis obliterans, areas of infarction could not be localized to the blood flow distribution of these vessels. Blood clotting/vessel clogging was seen in all four patients with vasculitis or endarteritis obliterans, but this was also observed in 10 patients without vasculitis or endarteritis obliterans. None of the patients developed disseminated intravascular coagulation.

Conclusions

Our results suggest that diffuse cerebral intravascular coagulation is an additional explanation of cerebral infarction complicating pneumococcal meningitis.