Vitamin B6 prevents Isocarbophos-induced posterior cerebral artery injury in offspring rats through up-regulating S1P receptor expression

We have previously reported that the long-term exposure of Isocarbophos, a kind of organophosphorus compounds, induces vascular dementia (VD) in rats. Studies have also shown that organophosphorus compounds have adverse effects on offsprings. Vitamin B6 is a coenzyme mainly involved in the regulation of metabolism and has been demonstrated to ameliorate VD. Sphingosine-1-phosphate (S1P), a biologically active lipid, plays a vital role in the cardiovascular system. However, whether S1P is involved in the therapeutic effects of Vitamin B6 on posterior cerebral artery injury has yet to be further answered. In the present study, we aimed to explore the potential influence of Vitamin B6 on Isocarbophos-induced posterior cerebral artery injury in offspring rats and the role of the S1P receptor in this process. We found that Vitamin B6 significantly improves the vasoconstriction function of the posterior cerebral artery in rats induced by Isocarbophos by the blood gas analysis and endothelium-dependent relaxation function assay. We further demonstrated that Vitamin B6 alleviates the Isocarbophos-induced elevation of ICAM-1, VCAM-1, IL-1, and IL-6 by using the enzyme-linked immunosorbent assay kits. By performing immunofluorescence and the western blot assay, we revealed that Vitamin B6 prevents the down-regulation of S1P in posterior cerebral artery injury. It is worth noting that Fingolimod, the S1P inhibitor, significantly inhibits the Vitamin B6-induced up-regulation of S1P in posterior cerebral artery injury. Collectively, our data indicate that Vitamin B6 may be a novel drug for the treatment of posterior cerebral artery injury and that S1P may be a drug target for its treatment.

To what degree is late life cognitive decline driven by age-related neuropathologies?

The ageing brain is vulnerable to a wide array of neuropathologies. Prior work estimated that the three most studied of these, Alzheimer's disease, infarcts, and Lewy bodies, account for ∼40% of the variation in late life cognitive decline. However, that estimate did not incorporate many other diseases that are now recognized as potent drivers of cognitive decline [e.g. limbic predominant age-related TDP-43 encephalopathy (LATE-NC), hippocampal sclerosis, other cerebrovascular conditions]. We examined the degree to which person-specific cognitive decline in old age is driven by a wide array of neuropathologies. Deceased participants (n = 1164) from two longitudinal clinical-pathological studies, the Rush Memory and Aging Project and Religious Orders Study, completed up to 24 annual evaluations including 17 cognitive performance tests and underwent brain autopsy. Neuropathological examinations provided 11 pathological indices, including markers of Alzheimer's disease, non- Alzheimer's disease neurodegenerative diseases (i.e. LATE-NC, hippocampal sclerosis, Lewy bodies), and cerebrovascular conditions (i.e. macroscopic infarcts, microinfarcts, cerebral amyloid angiopathy, atherosclerosis, and arteriolosclerosis). Mixed effects models examined the linear relation of pathological indices with global cognitive decline, and random change point models examined the relation of the pathological indices with the onset of terminal decline and rates of preterminal and terminal decline. Cognition declined an average of about 0.10 unit per year (estimate = -0.101, SE = 0.003, P < 0.001) with considerable heterogeneity in rates of decline (variance estimate for the person-specific slope of decline was 0.0094, P < 0.001). When considered separately, 10 of 11 pathological indices were associated with faster decline and accounted for between 2% and 34% of the variation in decline, respectively. When considered simultaneously, the 11 pathological indices together accounted for 43% of the variation in decline; Alzheimer's disease-related indices accounted for 30-36% of the variation, non-Alzheimer's disease neurodegenerative indices 4-10%, and cerebrovascular indices 3-8%. Finally, the 11 pathological indices combined accounted for less than a third of the variation in the onset of terminal decline (28%) and rates of preterminal (32%) and terminal decline (19%). Although age-related neuropathologies account for a large proportion of the variation in late life cognitive decline, considerable variation remains unexplained even after considering a wide array of neuropathologies. These findings highlight the complexity of cognitive ageing and have important implications for the ongoing effort to develop effective therapeutics and identify novel treatment targets.

Vessel Wall Enhancement and Focal Cerebral Arteriopathy in a Pediatric Patient with Acute Infarct and COVID-19 Infection

Herein, we report the findings of intracranial arterial wall enhancement, consistent with focal cerebral arteriopathy-inflammatory type, in a child presenting with acute infarct in the setting of coronavirus disease 2019 (COVID-19) infection. To our knowledge, this report provides the first description of vessel wall imaging findings in COVID-19-associated acute stroke.

A lower baseline glomerular filtration rate predicts high mortality and newly cerebrovascular accidents in acute ischemic stroke patients

Chronic kidney disease (CKD) is gradually recognized as an independent risk factor for cardiovascular and cardio-/cerebrovascular disease. This study aimed to examine the association of the estimated glomerular filtration rate (eGFR) and clinical outcomes at 3 months after the onset of ischemic stroke in a hospitalized Chinese population.Totally, 972 patients with acute ischemic stroke were enrolled into this study. Modified of Diet in Renal Disease (MDRD) equations were used to calculate eGFR and define CKD. The site and degree of the stenosis were examined. Patients were followed-up for 3 months. Endpoint events included all-cause death and newly ischemic events. The multivariate logistic model was used to determine the association between renal dysfunction and patients' outcomes.Of all patients, 130 patients (13.4%) had reduced eGFR (<60 mL/min/1.73 m), and 556 patients had a normal eGFR (≥90 mL/min/1.73 m). A total of 694 patients suffered from cerebral artery stenosis, in which 293 patients only had intracranial artery stenosis (ICAS), 110 only with extracranial carotid atherosclerotic stenosis (ECAS), and 301 with both ICAS and ECAS. The patients with eGFR <60 mL/min/1.73m had a higher proportion of death and newly ischemic events compared with those with a relatively normal eGFR. Multivariate analysis revealed that a baseline eGFR <60 mL/min/1.73 m increased the risk of mortality by 3.089-fold and newly ischemic events by 4.067-fold. In further analysis, a reduced eGFR was associated with increased rates of mortality and newly events both in ICAS patients and ECAS patients. However, only an increased risk of newly events was found as the degree of renal function deteriorated in ICAS patients (odds ratio = 8.169, 95% confidence interval = 2.445-14.127).A low baseline eGFR predicted a high mortality and newly ischemic events at 3 months in ischemic stroke patients. A low baseline eGFR was also a strong independent predictor for newly ischemic events in ICAS patients.

Angiographic Structural Differentiation between Native Arteriogenesis and Therapeutic Synangiosis in Intracranial Arterial Steno-Occlusive Disease

BACKGROUND AND PURPOSE

Encephaloduroarteriosynangiosis has been shown to generate collateral vessels from the extracranial-to-intracranial circulation in patients with Moyamoya disease and intracranial arterial steno-occlusive disease. The mechanisms involved are not well-understood. We hypothesized that angiogenesis is the leading mechanism forming collaterals after encephaloduroarteriosynangiosis because there are no pre-existing connections. Angiogenesis-generated collaterals should exhibit higher architectural complexity compared with innate collaterals.

MATERIALS AND METHODS

Pre- and postoperative digital subtraction angiograms were analyzed in patients enrolled in a prospective trial of encephaloduroarteriosynangiosis surgery. Branching angioscore, tortuosity index, and local connected fractal dimension were compared between innate and postoperative collaterals.

RESULTS

One hundred one angiograms (50 preoperative, 51 postoperative) were analyzed from 44 patients (22 with intracranial atherosclerosis and 22 with Moyamoya disease). There was a significantly higher median branching angioscore (13 versus 4, P < .001) and a lower median tortuosity index (1.08 versus 1.76, P < .001) in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals. Higher mean local fractal dimension peaks (1.28 ± 0.1 versus 1.16 ± 0.11, P < .001) were observed in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals for both intracranial atherosclerosis (P < .001) and Moyamoya disease (P < .001) groups. The observed increase in high connectivity was greater in the intracranial atherosclerosis group compared with patients with Moyamoya disease (P = .01).

CONCLUSIONS

The higher median branching angioscore and local connected fractal dimension, along with the lower median tortuosity index of encephaloduroarteriosynangiosis collaterals, are consistent with the greater complexity observed in the process of sprouting and splitting associated with angiogenesis.

High-resolution MRI vessel wall imaging in varicella zoster virus vasculopathy

Contrast-enhanced vessel wall imaging high-resolution MRI (HRMR) has revealed vessel wall thickening and enhancement in multiple intracranial vasculopathies, including varicella zoster virus (VZV) vasculopathy. We retrospectively reviewed a database of patients with virologically-verified VZV vasculopathy, who underwent initial and follow-up HRMR between April 2011 and May 2014. Six patients were identified. Baseline demographic and clinical characteristics were collected, including stroke risk factors, history of VZV-related disorders, neurological presentation, course and antiviral treatment. Initial HRMR in patients with VZV vasculopathy demonstrated various patterns of stenosis, vessel wall thickening and enhancement, predominantly in terminal internal carotid artery segments and the M1 segment of the middle cerebral arteries. Follow-up HRMR showed improvement of stenosis, with reduced vessel wall thickening and enhancement at multiple times after treatment. HRMR has the potential to assist in diagnosis and treatment of VZV vasculopathy.

Cytoskeletal reorganization evoked by Rho-associated kinase- and protein kinase C-catalyzed phosphorylation of cofilin and heat shock protein 27, respectively, contributes to myogenic constriction of rat cerebral arteries

Our understanding of the molecular events contributing to myogenic control of diameter in cerebral resistance arteries in response to changes in intravascular pressure, a fundamental mechanism regulating blood flow to the brain, is incomplete. Myosin light chain kinase and phosphatase activities are known to be increased and decreased, respectively, to augment phosphorylation of the 20-kDa regulatory light chain subunits (LC20) of myosin II, which permits cross-bridge cycling and force development. Here, we assessed the contribution of dynamic reorganization of the actin cytoskeleton and thin filament regulation to the myogenic response and serotonin-evoked constriction of pressurized rat middle cerebral arteries. Arterial diameter and the levels of phosphorylated LC(20), calponin, caldesmon, cofilin, and HSP27, as well as G-actin content, were determined. A decline in G-actin content was observed following pressurization from 10 mm Hg to between 40 and 120 mm Hg and in three conditions in which myogenic or agonist-evoked constriction occurred in the absence of a detectable change in LC20 phosphorylation. No changes in thin filament protein phosphorylation were evident. Pressurization reduced G-actin content and elevated the levels of cofilin and HSP27 phosphorylation. Inhibitors of Rho-associated kinase and PKC prevented the decline in G-actin; reduced cofilin and HSP27 phosphoprotein content, respectively; and blocked the myogenic response. Furthermore, phosphorylation modulators of HSP27 and cofilin induced significant changes in arterial diameter and G-actin content of myogenically active arteries. Taken together, our findings suggest that dynamic reorganization of the cytoskeleton involving increased actin polymerization in response to Rho-associated kinase and PKC signaling contributes significantly to force generation in myogenic constriction of cerebral resistance arteries.

Stenotic transverse sinus predisposes to poststenting hyperperfusion syndrome as evidenced by quantitative analysis of peritherapeutic cerebral circulation time

BACKGROUND AND PURPOSE

Hyperperfusion syndrome is a devastating complication of carotid stent placement. The shortening of cerebral circulation time after stent placement is seen as a good indicator of the development of hyperperfusion syndrome. The purpose of our study was to evaluate whether patients with ipsilateral transverse sinus stenosis are prone to having shortened cerebral circulation time after stent placement, subsequently leading to the possible development of hyperperfusion syndrome.

MATERIALS AND METHODS

Forty-nine patients with >70% unilateral carotid stenosis undergoing stent placement were recruited for analysis. Group A consisted of patients with a stenotic ipsilateral transverse sinus >50% greater than the diameter of the contralateral transverse sinus; the remaining patients were in group B. Quantitative DSA was used to calculate cerebral circulation time. Cerebral circulation time was defined as the time difference between the relative time to maximal intensity of ROIs in the proximal internal carotid artery and the internal jugular vein. ΔCCT was defined as cerebral circulation time before stent placement minus cerebral circulation time after stent placement. ΔCCT, white matter hyperintensity signals, and sulcal effacement in MR imaging were compared between the 2 groups.

RESULTS

ΔCCT was significantly shorter in group A (0.65 ± 1.3) than in group B (-0.12 ± 1.4). Three patients had white matter hyperintensity signals in group A, and 1 developed hyperperfusion syndrome. Group B showed no MR imaging signs of hyperperfusion syndrome.

CONCLUSIONS

Ipsilateral hypoplastic transverse sinus was associated with prolonged cerebral circulation time before stent placement and greatly shortened cerebral circulation time after stent placement. Inadequate venous drainage might play a role in impaired cerebral autoregulation and might influence the development of poststenting hyperperfusion syndrome.

[Effective thrombolytic therapy for calcified cerebral embolism originating from a calcified plaque in the internal carotid artery]

A 72-year-old man was transported to our emergency department after rear-ending another vehicle. He presented with acute left hemispatial neglect, left hemianopsia, and mild left hemiparesis. Computed tomography (CT) on admission showed a calcified embolus in the right middle cerebral artery. After intravenous thrombolytic therapy, the patient showed drastic improvement of neurological deficits. Follow-up CT showed disappearance of embolus, but distal migration of emboli to the downstream of the right middle cerebral artery was seen, sparing the massive territory of the right middle cerebral artery. Carotid duplex sonography and 3-dimensional CT angiography showed a calcified plaque with ulceration at the origin of the right internal carotid artery, representing the presumptive origin of the emboli. We report a rare case of effective intravenous thrombolysis for calcified cerebral embolism from the carotid artery. Further consideration of the mechanism, efficacy, and indication of intravenous thrombolysis for calcified cerebral emboli is needed.

Magnetic resonance angiography and vascular corrosion casting as tools in biomedical research: application to transgenic mice modeling Alzheimer's disease

In vivo imaging technologies are presently receiving considerable attention in the biomedical and pharmaceutical research areas. One of the principal imaging modalities is magnetic resonance imaging (MRI). The multiparametric nature of MRI enables anatomical, functional and even molecular information to be obtained non-invasively from intact organisms at high spatial resolution. Here we describe the use of one MRI modality, namely angiography (MRA), to non-invasively study the arterial vascular architecture of APP23 transgenic mice modeling Alzheimer's disease. Because the spatial resolution of the technique is limited, the in vivo studies are complemented by a powerful analysis of the vasculature using vascular corrosion casting. Both techniques revealed age-dependent blood flow alterations and cerebrovascular abnormalities in these mice. Our experience suggests that MRA complemented by cast analysis are important tools to describe vascular alterations and test new therapy concepts in animal models of AD. Furthermore, being non-invasive, MRA can also be applied to studies in patients suffering from this disease.

Saccular intracranial aneurysm: pathology and mechanisms

Saccular intracranial aneurysms (sIA) are pouch-like pathological dilatations of intracranial arteries that develop when the cerebral artery wall becomes too weak to resist hemodynamic pressure and distends. Some sIAs remain stable over time, but in others mural cells die, the matrix degenerates, and eventually the wall ruptures, causing life-threatening hemorrhage. The wall of unruptured sIAs is characterized by myointimal hyperplasia and organizing thrombus, whereas that of ruptured sIAs is characterized by a decellularized, degenerated matrix and a poorly organized luminal thrombus. Cell-mediated and humoral inflammatory reaction is seen in both, but inflammation is clearly associated with degenerated and ruptured walls. Inflammation, however, seems to be a reaction to the ongoing degenerative processes, rather than the cause. Current data suggest that the loss of mural cells and wall degeneration are related to impaired endothelial function and high oxidative stress, caused in part by luminal thrombosis. The aberrant flow conditions caused by sIA geometry are the likely cause of the endothelial dysfunction, which results in accumulation of cytotoxic and pro-inflammatory substances into the sIA wall, as well as thrombus formation. This may start the processes that eventually can lead to the decellularized and degenerated sIA wall that is prone to rupture.

[Mitochondrial arteriopathy as a cause of spontaneous dissection of cerebral arteries]

The vascular wall weakness caused by dysplastic alterations predisposes to the spontaneous dissection of cerebral arteries. The authors hypothesized for the first time that dysplasia might be the result of mitochondrial cytopathy. To test this hypothesis, the muscle biopsy was conducted in 3 male patients, aged 30-38 years, with the spontaneous dissection of the internal carotid (2) and posterior cerebral (1) arteries. Clinically dissections manifested by ischemic stroke (2) or the peripheral paresis of the hypoglossal nerve (1). The morphological study of fresh frozen sections of muscle by modified Gomori trichrome method revealed ragged-red fibers The histochemical study showed the severe decrease of the stain on succinate dehydrogenase and cytochrome-c-oxidase as well as the focal intensive staining of peripheral regions of muscle fibers. The complex of found changes is characteristic for a mitochondrial pathology. No patients had A3243G tRNA gene mutation, the most common mutation for MELAS. The serum lactate level was elevated only in one patient. We suggest that the mitochondrial disorder occurs not only in muscle, but also in cerebral artery wall--mitochondrial arteriopathy, which predisposes to spontaneous cerebral artery dissection.

Dual-energy CTA with bone removal for transcranial arteries: intraindividual comparison with standard CTA without bone removal and TOF-MRA

RATIONALE AND OBJECTIVES

Dual-source computed tomography enables bone removal on computed tomographic angiographic data on the basis of simultaneous dual-energy (DE) acquisition. The aim of this study was to evaluate the impact of this technique for the assessment of transcranial arteries. Therefore, the degree of stenosis of the transcranial arteries on DE computed tomographic angiography (CTA) with bone removal was compared to those on standard CTA and time-of-flight (TOF) magnetic resonance angiography (MRA).

MATERIALS AND METHODS

DE-CTA was performed using a dual-source computed tomographic scanner in 50 patients with suspected cerebrovascular disease. From the source images on DE-CTA, data sets with and without bone removal were reconstructed. TOF-MRA was performed on a 1.5-T scanner. Two blinded radiologists evaluated the segments of the internal carotid artery (C2-C7), the vertebral artery (V4), and the basilar artery for degree of stenosis. A five-step scale (0%-49%, 50%-69%, 70%-89%, 90%-99%, and 100% [occlusion]) for degree of stenosis was applied. Wilcoxon's signed-rank test was used for statistical analysis.

RESULTS

The degrees of stenosis on standard CTA were consistent with those on TOF-MRA in all segments. In contrast, DE-CTA showed significantly higher degrees of stenosis compared to standard CTA and TOF-MRA in both C2 segments (P < .001). In addition, DE-CTA revealed a significantly higher degree of stenosis compared to standard CTA and TOF-MRA in the left C4 segment (P < .01 and P < .005, respectively). All other segments showed no significant differences of stenosis among TOF-MRA, DE-CTA, and standard CTA.

CONCLUSIONS

Compared to TOF-MRA, standard CTA showed similar results. In contrast, DE-CTA revealed significant overestimation of stenosis for segments with close relations to bony structures as well as in calcified stenosis. Consequently, such findings on DE-CTA require confirmation with standard CTA or MRA to eliminate false-positive results.

Association of HTRA1 mutations and familial ischemic cerebral small-vessel disease

BACKGROUND

The genetic cause of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), which is characterized by ischemic, nonhypertensive, cerebral small-vessel disease with associated alopecia and spondylosis, is unclear.

METHODS

In five families with CARASIL, we carried out linkage analysis, fine mapping of the region implicated in the disease, and sequence analysis of a candidate gene. We also conducted functional analysis of wild-type and mutant gene products and measured the signaling by members of the transforming growth factor beta (TGF-beta) family and gene and protein expression in the small arteries in the cerebrum of two patients with CARASIL.

RESULTS

We found linkage of the disease to the 2.4-Mb region on chromosome 10q, which contains the HtrA serine protease 1 (HTRA1) gene. HTRA1 is a serine protease that represses signaling by TGF-beta family members. Sequence analysis revealed two nonsense mutations and two missense mutations in HTRA1. The missense mutations and one of the nonsense mutations resulted in protein products that had comparatively low levels of protease activity and did not repress signaling by the TGF-beta family. The other nonsense mutation resulted in the loss of HTRA1 protein by nonsense-mediated decay of messenger RNA. Immunohistochemical analysis of the cerebral small arteries in affected persons showed increased expression of the extra domain-A region of fibronectin and versican in the thickened tunica intima and of TGF-beta1 in the tunica media.

CONCLUSIONS

CARASIL is associated with mutations in the HTRA1 gene. Our findings indicate a link between repressed inhibition of signaling by the TGF-beta family and ischemic cerebral small-vessel disease, alopecia, and spondylosis.

[Clinical application of the three-dimensional CT of the flat-panel digital subtraction angiography system]

OBJECTIVE

To evaluate the clinical value of the three-dimensional (3D) CT module of the flat-panel digital subtraction angiography (DSA) system.

METHODS

A retrospective analysis was conducted among 278 patients receiving examination with rotational 3D-CT of INNOVA 3100 flat-panel DSA system. AW4.3-04 workstation was used to perform the 3D reconstruction and INNOVA CT reconstruction, and the imaging data were analyzed in comparison with the clinical results.

RESULTS

The 3D-CT of the flat panel DSA system displayed the conditions of cerebral aneurysms in 54 cases, cerebral arteriovenous malformation in 25 cases, and the intracranial conditions in 24 cases. The blood supply and tumor vessels were clearly displayed in 57 cases, and the effects of embolization and endovascular stenting were evaluated in 27 and 21 cases, respectively. The rotational 3D-CT was used to evaluate complete embolization in 24 cases, and failed to display the feeding arteries of small tumors in 11 cases. The vascular lesions, biliary tract lesions, and the occurrence of hemorrhage during interventional therapy were observed in 58, 5 and 25 cases, respectively.

CONCLUSION

The 3D-CT module of the flat-panel DSA system can easily display abnormal vascular lesions and provide comprehensive anatomical information to facilitate interventional therapies and complication monitoring.

Poststroke depression in patients with small subcortical infarcts

OBJECTIVES

Small subcortical infarcts (SSIs) can result from small vessel disease (SVD) and intracranial and extracranial large artery disease (LAD). No study has explored poststroke depression (PSD) in different etiological types of SSIs.

METHODS

Patients with SSIs resulting from LAD and SVD were included in the study. Poststroke depression was evaluated with the 15-item version of the geriatric depression scale (GDS) 3 months after stroke.

RESULTS

Of the 127 patients with SSIs, 44 had LAD and 83 had SVD. The LAD group had a significantly higher mean GDS score and higher frequency of PSD (p<0.05). The etiological type LAD was a significant independent risk factor for PSD.

CONCLUSION

PSD is more common in patients with SSIs resulting from LAD. This suggests that cerebral blood perfusion may play an important role in the development of PSD.

Endovascular management of subclavian artery injury due to Hickman line insertion in a patient with coagulopathy

Vascular injuries after insertion of a Hickman line in neck are not uncommon. We present a case report of a patient of acute myeloid leukaemia with coagulopathy, who underwent right Hickman line insertion by a radiologist. She sustained a life threatening right subclavian artery injury which was managed by deploying endovascular covered stent. We recommend open surgical technique for Hickman line insertion under these circumstances after correction of coagulopathy.

Hereditary systemic angiopathy (HSA) with cerebral calcifications, retinopathy, progressive nephropathy, and hepatopathy

Several hereditary conditions affecting cerebral, retinal and systemic microvessels have recently been described. They include CADASIL, CRV, and HERNS. We here report on a variant form of a hereditary systemic angiopathy (HSA) affecting two generations of a Caucasian family. Clinical symptoms of HSA appear in the mid-forties and are characterized by visual impairment, migraine-like headache, skin rash, epileptic seizures, progressive motor paresis and cognitive decline. Late symptoms include hepatic and renal failure. Retinal capillary microaneurysms and arteriolar tortuosity are associated with marked optic disc atrophy. Radiological hallmarks consist of multiple cerebral calcifications and tumor-like subcortical white matter lesions. Brain, peripheral nerve, muscle, kidney and colon biopsies have revealed a multi organ small vessel involvement with partly altered endothelium, perivascular inflammation and thrombotic microangiopathy. No curative therapeutic options are known for hereditary cerebral vasculopathies. The use of cyclophosphamide, azathioprine and methotrexate was of no benefit in our cases of HSA. Early diagnosis of hereditary systemic angiopathies is important in order to prevent patients from repetitive invasive diagnostic measures and to avoid the use of inappropriate and potentially harmful drugs.

Changes in brain volume after EC-IC bypass surgery

We studied changes in brain volume on magnetic resonance imaging in 10 patients with and without EC-IC bypass surgery who met the inclusion criteria for the Japanese EC-IC bypass trial, a multicenter, randomized, double-blind, prospective study of patients with hemodynamic brain ischemia due to cerebral artery occlusive disease. We also examined the association of cerebral hemodynamics on single photon emission computed tomography with the changes in brain volume. As a result, the affected/unaffected ratio of the % brain volume declined in patients without EC-IC bypass surgery (p < 0.02, n = 4), and the affected/unaffected % rCBF ratio increased in patients with the surgery (p < 0.03, n = 6). Acetazolamide reactivity increased in the affected hemisphere of patients with surgery (p < 0.01). And also two-year increase (decrease) in acetazolamide reactivity of the affected hemisphere showed a significant positive correlation with 2-year changes in the affected/unaffected % brain volume ratio (R2 = 0.737, p = 0.0007). Change in acetazolamide reactivity might be a good predictor for brain atrophy in cerebral artery occlusive disease.

Noninvasive detection of diffuse intracranial disease

BACKGROUND AND PURPOSE

Intracranial arterial stenosis increases flow velocities on the upslope of the Spencer's curve of cerebral hemodynamics. However, the velocity can decrease with long and severely narrowed vessels. We assessed the frequency and accuracy for detection of focal and diffuse intracranial stenoses using novel diagnostic criteria that take into account increased resistance to flow with widespread lesions.

METHODS

We evaluated consecutive patients referred to a neurovascular ultrasound laboratory with symptoms of cerebral ischemia. Transcranial Doppler mean flow velocities were classified as normal (30 to 99 cm/s), high and low. Pulsatility index >or=1.2 was considered high. Focal intracranial disease was defined as >or=50% diameter reduction by the Warfarin Aspirin in Symptomatic Intracranial Disease criteria. Diffuse disease was defined as stenoses in multiple intracranial arteries, multiple segments of one artery, or a long (>1 cm) stenosis in one major artery on contrast angiography (CT angiography or digital subtraction angiography) as the gold standard.

RESULTS

One hundred fifty-three patients (96 men, 76% white, age 62+/-15 years) had previous strokes (n=135) or transient ischemic attack (n=18). Transcranial Doppler detection of focal and diffuse intracranial disease had sensitivity 79.4% (95% CI: 65.8% to 93%), specificity 92.4% (95% CI: 87.7% to 97.2%), positive predictive value 75.0% (95% CI: 60.9% to 89.2%), negative predictive value 94.0% (95% CI: 89.7% to 98.3%), and overall accuracy 89.5% (95% CI: 84.5% to 94.4%). After adjustment for stroke risk factors, transcranial Doppler findings of low mean flow velocities and high pulsatility index in a single vessel were independently associated with angiographically demonstrated diffuse single vessel intracranial disease, whereas low mean flow velocities/high pulsatility index in multiple vessels were related to multivessel intracranial disease (OR: 19.7, 95% CI: 4.8 to 81.2, P<0.001).

CONCLUSIONS

Diffuse intracranial disease may have a higher than expected frequency in a select stroke population and can be detected with noninvasive screening.

Connective tissue and vascular phenotype in patients with cervical artery dissection

BACKGROUND

Clinical observations and electron microscopic investigation of skin biopsies demonstrated connective tissue abnormalities in a sizeable proportion of patients with spontaneous cervical artery dissection (sCAD), suggesting an unknown connective tissue disorder as a risk factor for sCAD.

OBJECTIVE

To evaluate in a case-control setting if patients with sCAD exhibit clinical signs indicative of a connective tissue disorder or show a vascular phenotype.

METHODS

We investigated 43 consecutive patients with sCAD and 43 consecutive patients of similar age with ischemic stroke of other etiology. All patients underwent standardized MRI of the head and neck. The clinical investigation contained 25 items characteristic for connective tissue diseases such as hyperextensible skin, articular hypermobility, capillary fragility, and facial stigmata. A sum score counting all positive items was calculated. Additionally, the diameter of the common carotid artery (CCA) and vertebral artery (VA) and heart valve pathologies were assessed.

RESULTS

Connective tissue sum scores did not differ between the sCAD group (mean 2.37 +/- 2.1, median 2) and the control group (mean 1.95 +/- 1.9, median 2, p = 0.34). One sCAD patient had osteogenesis imperfecta (2.3%) and exhibited the highest sum score of 8. The diameter of the CCA and VA and the prevalence of heart valve pathologies did not show any significant differences between groups.

CONCLUSION

The connective tissue and vascular phenotype did not differ significantly between patients with spontaneous cervical artery dissection (sCAD) and control subjects with ischemic stroke of other etiology. These findings argue against a clinically apparent connective tissue disorder underlying sCAD. The prevalence of known connective tissue diseases in sCAD patients is low.

Alien limb following posterior cerebral artery stroke: Failure to recognize internally generated movements?

We describe two rare cases of alien limb syndrome following right posterior cerebral artery (PCA) stroke. Both patients present with left hemianopia, visual neglect and proprioceptive loss in addition to their alien limb symptoms. Lesion subtraction from seven control PCA patients revealed that medial parietal-occipital and thalamic areas were selectively damaged in the alien limb patients. We propose that loss of the sense of motor intention and internal model of the current state of the arm, combined with deficient proprioceptive and visual feedback of the moving limb, are critical for genesis of posterior alien limb and discuss how affected regions normally function to ensure awareness of self-generated motor activity.

Arterial ischemic stroke in a child with beta-thalassemia trait and methylentetrahydrofolate reductase mutation

Genetic and acquired disorders that foster a procoagulable state represent risk factors for stroke in childhood. Although an increased incidence of thromboembolic complications has been reported in patients with thalassemia, severe cerebral thromboembolism has rarely been observed in patients with beta-thalassemia minor. This article describes a case study of a 1-year-old boy who presented with left-sided hemiparesis, seizures, microcytic anemia, and recent infection with reactive thrombocytosis. Ischemic infarction in the territory of the right middle cerebral artery was confirmed by magnetic resonance imaging and magnetic resonance angiography. Genetic tests showed that the patient was heterozygous for the beta(degrees) -thalassemia IVS-I-1 mutation and homozygous for the methylentetrahydrofolate reductase C677T mutation. Based on these findings, it was concluded that the synergistic effects of multiple, genetic, and acquired prothrombotic risk factors brought about the hypercoagulable state that resulted in overt stroke in a thalassemic patient in early childhood.

Dysarthria due to Supratentorial and Infratentorial Ischemic Stroke: A Diffusion-Weighted Imaging Study

BACKGROUND AND PURPOSE

Dysarthria characterized by slurring with imprecise articulation without evidence of aphasia is a frequent symptom in the acute phase of cerebral ischemia, although there is little knowledge on its anatomic specificity and spectrum of associated clinical characteristics regarding diffusion-weighted imaging (DWI).

METHODS

An investigation of 101 consecutive patients with sudden-onset dysarthria due to a single or multiple lesions on DWI, corresponding to 8.7% of 1,160 patients with ischemic stroke, was made. The presence of lesions of the cranial arteries was sought by magnetic resonance angiography and reviewed with a three-dimensional rotating cineangiographic method.

RESULTS

Dysarthria was mostly associated with a supratentorial lesion (63%) and with a classic lacunar stroke syndrome in 45% of patients. Lacunar lesions on DWI were found in 69 (68%) patients, while only 45 of the patients (65%) with a lacunar infarct presented a classic lacunar syndrome with dysarthria. Pure dysarthria occurred in 15% of patients, dysarthria + pure motor hemiparesis in 14%, dysarthria + ataxic hemiparesis in 11%, dysarthria + clumsy hand syndrome in 7%, dysarthria + pure sensory stroke in 3%, dysarthria + central facial paresis in 8% and lingual paresis occurred in 2%. The lesions were due to small-artery disease in 41%, large-artery disease in 15%, cardioembolism in 10% and a mixed etiology in 3%. The cause of stroke was not identified in 17 patients. Lesions on DWI were found mainly in the corona radiata (n = 18), middle cerebral artery territory, including the motor cortex and/or insular cortex (n = 13), striatocaudate nuclei (n = 11), primary motor cortex (n = 10), internal capsule (n = 7), pons (n = 25), pontobulbar junction (n = 5) and the thalamomesencephalic junction (n = 4). Isolated cerebellar infarctions (n = 6) or associated brainstem lesions (n = 6) affected mostly the superior cerebellar artery or the posterior inferior cerebellar artery territory.

CONCLUSION

Cortical involvement was more frequent in patients with pure dysarthria than those with dysarthria and additional neurological signs, while the frequency of pontine involvement was higher in patients with additional neurological signs than those with pure dysarthria. One third of the patients with dysarthria had multiple lesions on DWI, and the most common cause of stroke was small-artery disease. Pure dysarthria, dysarthria with lingual paresis, dysarthria with clumsy hand and dysarthria with facial paresis had predictive value for lacunar lesions.

Vertebral artery hypoplasia: A predisposing factor for posterior circulation stroke?

We determined in 725 sequentially admitted first-ever stroke patients, using color-coded duplex flow imaging of the V2 segment, whether vertebral artery hypoplasia (VAH) (diameter < or = 2.5 mm) was more frequent (13%) in posterior circulation territory infarction (247) than in strokes in other territories (4.6%). This difference is significant (p < 0.001), whereas all other risk factors (hypertension, hyperlipidemia, diabetes, smoking) were equally (p > 0.05) distributed. Patients with VAH may be predisposed to stroke in the posterior circulation.

Complement activation associates with saccular cerebral artery aneurysm wall degeneration and rupture

OBJECTIVE

Saccular cerebral artery aneurysm (SCAA) wall degeneration and inflammatory cell infiltrations associate with aneurysm rupture and subarachnoid hemorrhage, resulting in a devastating form of stroke. The complement system is the key mediator of inflammation and household processing of injured tissue. We studied how complement activation associates with SCAA wall degeneration and rupture to better understand the pathobiology of SCAA wall rupture.

METHODS

Unruptured (n = 26) and ruptured (n = 32) SCAA fundi resected after microsurgical clipping were studied by immunostaining for complement activation (membrane attack complex [MAC]) and by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction for related cell death. Complement activation was correlated with clinical and other histological parameters. Electromicroscopy and immunoelectron microscopy were used for locating MAC depositions at the ultrastructural level.

RESULTS

MAC localized consistently in a decellularized layer in the outer SCAA wall, and was found in all SCAA samples. The percentage of MAC-positive area relative to the total SCAA wall surface area (range, 5-77%) was greater in ruptured (n = 25; median, 39%) than in unruptured SCAAs (n = 18; median, 20%; P = 0.005). It also associated significantly with SCAA wall degeneration (P < 0.001), de-endothelialization(P < 0.001), and CD163+ macrophage (P = 0.023) and T-lymphocyte (P = 0.030) infiltrations. Apoptotic terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive nuclei and MAC were located at the same wall areas in four out of 14 double-stained samples, but no double-positive cells were found. Electromicroscopy and immunoelectron microscopy of an unruptured SCAA showed cell death in the MAC-positive layers in the outer SCAA wall.

CONCLUSION

These data suggests that complement activation and MAC formation are involved in SCAA wall degeneration and rupture.

Changes in Brain Volume 2 Years after Extracranial-Intracranial Bypass Surgery: A Preliminary Subanalysis of the Japanese EC-IC Trial

BACKGROUND AND METHODS

We studied changes in brain volume on magnetic resonance imaging in 10 patients with and without extracranial-intracranial (EC-IC) bypass surgery who met the inclusion criteria for the Japanese EC-IC Bypass Trial, a multicenter, randomized, prospective study of patients with hemodynamic brain ischemia due to cerebral artery occlusive disease. We also examined the association of cerebral hemodynamics on single-photon emission computed tomography with the changes in brain volume.

RESULTS

The affected/unaffected ratio of the percent brain volume declined in patients without EC-IC bypass surgery (p < 0.02, n = 4), and the affected/unaffected percent regional cerebral blood flow ratio increased in patients with the surgery (p < 0.03, n = 6). Acetazolamide reactivity increased in the affected hemisphere of patients with surgery (p < 0.01). Two-year increase (decrease) in acetazolamide reactivity of the affected hemisphere showed a significant positive correlation with 2-year changes in the affected/unaffected percent brain volume ratio (R2 = 0.737, p = 0.0007).

CONCLUSIONS

Change in acetazolamide reactivity might be a good predictor for brain atrophy in cerebral artery occlusive disease.

Aspirin or Anticoagulants in Stenosis of the Middle Cerebral Artery:A Randomized Trial

BACKGROUND

We report the results of an open, randomized, multicenter trial that compared the efficacy of aspirin to oral anticoagulants (OA) for the prevention of vascular events in patients with symptomatic stenosis of the middle cerebral artery (MCA).

METHODS

Participants were randomly assigned to receive 300 mg/day of aspirin or a dose of OA (target INR 2-3). The MCA stenosis was demonstrated by conventional angiography or by at least two noninvasive examinations. Patients had either transient ischemic attack or cerebral infarct (CI) attributable to the MCA stenosis within 90 days before inclusion. The primary endpoint was: nonfatal CI, nonfatal acute myocardial infarct, vascular death and major hemorrhage. The patients were followed-up for a minimum of 1 year and a maximum of 3 years.

RESULTS

The study included 28 patients (14 in each treatment group); the average age was 67 +/- 9.9 years. Men constituted 68% of the patients. After a mean follow-up of 23.1 +/- 10.9 months, there were no recurrences of CI in both groups. No endpoint was reported in the aspirin group, but 2 patients in the OA group (14.3%) exhibited vascular events: 1 acute myocardial infarct and 1 intracerebral hemorrhage). However, this difference was not statistically significant (p = 0.48).

CONCLUSIONS

Our study suggests that aspirin is the treatment of choice for the prevention of vascular events in patients with symptomatic MCA stenosis.

Intracranial 2D and 3D DSA with flat panel detector of the direct conversion type: initial experience

The purpose of this study was to compare the image quality of two-dimensional (2D) digital subtraction angiography (DSA) between a flat panel detector (FPD) of the direct conversion type with low radiation dose and a conventional image intensifier (I.I.)-TV system, and to assess 3D DSA with the FPD system in the depiction of intracranial vessels. Fifteen consecutive patients (five men, ten women; age range: 18-82 years; mean age: 55.5 years) were prospectively included in this study. All patients underwent 2D DSA with both the FPD and I.I.-TV system in one projection. The radiation doses during angiography were evaluated using a phantom. The 3D DSA images were created from the rotational DSA data with the FPD system. Two blinded radiologists independently evaluated 2D DSA with the FPD system and I.I.-TV system using a 5-point assessment scale (excellent to not visible) to assess the depiction of intracranial vessels. MIP and volume rendering (VR) images of 3D DSA with the FPD system were also evaluated using a 5-point scale (excellent to not visible). DSA and fluoroscopy dose measurements with the phantom showed a dose reduction of approximately 85% and 9% with the FPD system compared with the I.I.-TV system, respectively. For 2D DSA, the FPD system was significantly superior to the I.I.-TV system with respect to the visibility of the peripheral and perforating vessels (p<0.05). The peripheral and perforating vessels were also sufficiently visualized on MIP images of 3D DSA in all 15 cases. Our FPD system was found to be superior to the I.I.-TV system in visualizing small intracranial vessels combined with a significant reduction of radiation dose, and was able to create high-quality 3D DSA images on which high spatial resolution allowed precise visualization of small vessels such as perforating ones.

Preserved cognition and functional independence after a large right posterior cerebral artery infarct: longitudinal clinical and neuropathological findings

BVR was 77 years old when he sustained a large posterior cerebral artery territory infarct. Medical, cognitive and functional data collected on four occasions over 10 years initially revealed circumscribed neurological signs, no functional or cognitive deficits. BVR became significantly impaired only after two other strokes, 3 years before death. On brain MRI, the lesions involved large portions of the right occipital and temporal cortices, the right thalamus, and the left cerebellum, as well as thinning of the corpus callosum. Postmortem investigations revealed additional recent vascular lesions in the occipital region. This case study underscores the importance of comprehensive assessment methods combining neurological, neuroimaging and cognitive tools.

Relationship between cerebral circulatory reserve and oxygen extraction fraction in patients with major cerebral artery occlusive disease: a positron emission tomography study

BACKGROUND AND PURPOSE

The present study examined the relationship between circulatory and metabolic reserve in patients with hemodynamic impairment.

METHODS

Positron emission tomography was used to investigate 40 patients with major cerebral artery occlusive disease. The ratio of cerebral blood volume to cerebral blood flow (CBV/CBF) and vasoreactivity in response to hypercapnia (%CBF(hypercapnia)) and acetazolamide (ACZ) stress (%CBF(ACZ)) were measured to evaluate circulatory reserve. Oxygen extraction fraction (OEF) was measured to evaluate metabolic reserve. To detect relationships between circulation reserve and OEF, cerebral hemispheres were grouped into 5 or 6 stepwise groups based on reduction of circulation reserve.

RESULTS

OEF was significantly elevated in hemispheres with CBV/CBF > or =0.11 minutes and in hemispheres with %CBF(hypercapnia) <0%. OEF was significantly increased according to %CBF(ACZ) in hemispheres with %CBF(ACZ) <15% and plateaued at levels below -15%.

CONCLUSIONS

Metabolic reserve consumption began at CBV/CBF > or =0.11 minutes, CBF(hypercapnia) <0%, and CBF(ACZ) <15%.

Aneurysms located at the proximal anterior cerebral artery and anterior communicating artery associated with middle cerebral artery aplasia: case report

BACKGROUND

Aneurysms arising from the proximal anterior cerebral artery (ACA) are quite rare. Here, we report upon such a case of aneurysms located at the proximal ACA and anterior communicating artery associated with middle cerebral artery (MCA) aplasia.

CASE DESCRIPTION

A 64-year-old woman complained of severe headache. Brain computed tomography scans demonstrated acute subarachnoid hemorrhage. Angiograms showed 2 aneurysms located at the anterior communicating artery and proximal ACA, but did not show an MCA shadow on the lesion side. Instead, multiple collateral vessels ran toward the sylvian fissure and supplied the MCA territory, together with hypertrophied perforating branches. The operative findings confirmed that the cordlike rudimentary MCA had no internal blood flow. The 2 aneurysms were secured by neck clipping.

CONCLUSION

The combined effects of these anomalies on the hemodynamic equilibrium of the arteries and the genesis of the aneurysms are noteworthy.

Anomalous internal carotid anastomosis to contralateral anterior cerebral artery

BACKGROUND

Many anomalies and variants in vascular anatomy have been reported in relation to the anterior cerebral artery (ACA).

PATIENTS AND METHODS

We encountered an apparently novel anomaly in a 30-year-old man admitted for disturbance of consciousness following a traffic accident. Computed tomography revealed an acute subdural hematoma and subarachnoid hemorrhage.

RESULTS AND CONCLUSIONS

No vascular abnormalities related to the hemorrhage were detected by conventional angiography, so we concluded that the bleeding was of traumatic origin. Anomalous origin of the ACA was disclosed incidentally, with both A1 segments arising from the right internal carotid artery; no normal A1 segment of the left ACA was visualized. We discuss possible bases for this anomalous origin.

Negative ultrasound findings in patients with cervical artery dissection

BACKGROUND

Cervical artery dissection (CAD) is a common cause of ischemic stroke in the younger age group. Modern imaging techniques allow the depiction of the mural hematoma, even in CADs with only subtle vessel alterations. The aim of this retrospective study was (1) to characterize the angiological features in CAD and (2) to determine the frequency of initially normal ultrasonography (US) findings.

METHODS

86 patients aged 44 +/- 11 years with CAD of the internal carotid (ICA), (n = 55) or the vertebral artery (VA), (n = 31), admitted to our hospital within 8 days (mean 1.6 days) of symptom onset, were included. CAD was confirmed either by CT-angiography, MRI of the neck, MR-angiography or digital substraction angiography (DSA) and was compared with the results of the initial as well as repeated US examinations of the arteries supplying the brain.

RESULTS

In 75 patients (81.2 %) signs of vessel stenosis or occlusion were found while 11 patients (12.8%) with CAD of the ICA (n = 9) and the VA (n = 2) had normal US findings. The site of dissection in the US negative patients was highly variable without a predilection site. In 2 of 7 patients with repeated US examinations, complete vessel occlusion was found on follow-up, while in 5 patients again normal results were found. In four patients, there were changing findings in two alternative confirming imaging methods (MRI/DSA, CT/MRI) and in one patient conflicting findings (CT/MRI). Brain infarctions had occurred in 7 of the initially sonographically normal patients while the other 4 had suffered from transient (n = 2) or local (n = 2) symptoms only.

CONCLUSION

Approximately 1 out of 8 patients with subsequently proven CAD has negative initial neurovascular US findings despite comprehensive examination. In patients with suspected CAD and negative US examination, repeated US examinations and further diagnostic imaging, especially MRI is necessary.