[Show abstract][Hide abstract] ABSTRACT: Coronary artery disease (CAD) may coexist with extracranial carotid artery stenosis (ECAS), but the influence of CAD on procedure-related complications after carotid artery stenting (CAS) has not been well investigated. The study aimed to determine the impact of CAD on the occurrence of peri-CAS cerebral ischemic lesions on diffusion-weighted imaging (DWI) scanning.
Coronary angiography was performed within six months before CAS. DWI scanning was repetitively done within 1 week before and after CAS. Clinical outcome measures were stroke, angina, myocardial infarction and death within 30 days.
Among 126 patients (69.5±9.0 years) recruited for unilateral protected CAS, 33 (26%) patients had peri-CAS DWI-positive lesions. CAD was noted in 79% (26 in 33) and 48% (45 in 93) of patients with and without peri-CAS DWI-positive lesions (OR, 4.0; 95% CI, 1.6-10.0; P = .0018), and the number of concomitant CAD on coronary angiography was positively correlated with the risk for peri-CAS DWI-positive lesions (P = .0032). In patients with no CAD (n = 55), asymptomatic CAD (n = 41) and symptomatic CAD (n = 30), the occurrence rates of peri-CAS DWI-positive lesions were 13%, 41% and 30% (P = .0048), and the peri-CAS stroke rates were 2%, 7% and 0% (P = .2120).
The severity of morphological CAD and the presence of either symptomatic or asymptomatic CAD are associated with the occurrence of peri-CAS cerebral ischemic lesions.
[Show abstract][Hide abstract] ABSTRACT: We enrolled 221 patients with elective carotid artery stenting (CAS). Patients with contralateral carotid stenosis exceeding 50%, insufficient vertebral artery (VA) flows, or angioplasty at subclavian artery were excluded. All patients underwent serial cerebral ultrasound studies. Of the 116 included patients, the direction of ophthalmic artery (OA) flow was forward in 74 patients while reversed in 42. The reversed flow group had worse ipsilateral stenosis, higher hemoglobin, and cardiac output. After CAS, the reversed flow group had an immediate recovery of ipsilateral internal carotid artery flow volume (FV; P < .0001), time average velocity (TAV) of middle cerebral artery (P = .02), and normalization of OA flow. The forward flow group had gradual decrement in TAV of contralateral anterior cerebral artery (P = .01) and total FV of VA (P = .001). Our results suggest CAS improves cerebral hemodynamics through different ways regardless of the direction of OA flow.
[Show abstract][Hide abstract] ABSTRACT: New and improved techniques have been continuously introduced into CT and MR imaging modalities for the diagnosis and therapy planning of acute stroke. Nevertheless, non-contrast CT (NCCT) is almost always used by every institution as the front line diagnostic imaging modality due to its high affordability and availability. Consequently, the potential reward of extracting as much clinical information as possible from NCCT images can be very great. Intravenous tissue plasminogen activator (tPA) has become the gold standard for treating acute ischemic stroke because it is the only acute stroke intervention approved by the FDA. ASPECTS scoring based on NCCT images has been shown to be a reliable scoring method that helps physicians to make sound decisions regarding tPA administration. In order to further reduce inter-observer variation, we have developed the first end-to-end automatic ASPECTS scoring system using a novel method of contralateral comparison. Due to the self-adaptive nature of the method, our system is robust and has good generalizability. ROC analysis based on evaluation of 103 subjects who presented to the stroke center of Chang Gung Memorial Hospital with symptoms of acute stroke has shown that our system's dichromatic classification of patients into thrombolysis indicated or thrombolysis contraindicated groups has achieved a high accuracy rate with AUC equal to 90.2 %. The average processing time for a single case is 170 s. In conclusion, our system has the potential of enhancing quality of care and providing clinical support in the setting of a busy stroke or emergency center.
No preview · Article · Jan 2014 · Journal of Digital Imaging
[Show abstract][Hide abstract] ABSTRACT: Several coexisting diseases have been reported in patients with moyamoya vasculopathy (MMV), but studies of quasi-moyamoya disease (quasi-MMD) are rare. This study aims to investigate the frequency of known coexisting diseases in patients with quasi-MMD and to compare quasi-MMD with moyamoya disease (MMD).
Between 2000 and 2011, we retrospectively screened patients with International Classification of Diseases, Ninth Revision, code of 4375 (MMD) in the Health Information System of our hospital. The vascular images of each patient were confirmed by 2 neurologists and 1 neuroradiologist based on the diagnostic criteria of Japan Ministry of Health and Welfare. We excluded the patients with missing images and erroneous diagnosis. Demographics, coexisting diseases, laboratory data, treatment, and recurrent strokes were recorded. The eligible patients were divided into quasi-MMD and MMD groups according to the presence or absence of coexisting diseases.
MMV was found in 90 patients including 37 (41.1%) quasi-MMD and 53 (58.9%) MMD. Atherosclerosis (32.4%) and thyroid disease (29.7%) were the leading coexisting diseases in quasi-MMD. Patients with MMD became symptomatic in a bimodal age distribution, whereas patients with quasi-MMD became symptomatic in a single-peak distribution. The prognosis of recurrent strokes was similar between quasi-MMD and MMD based on Kaplan-Meier analysis.
A bimodal distribution of onset age was noted in MMD, whereas a single-peak distribution was found in quasi-MMD. Coexisting diseases were usually underevaluated but were more common than expected in patients with MMV. Atherosclerosis and thyroid diseases were the leading coexisting diseases in different preferential age.
Full-text · Article · Jan 2014 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association
[Show abstract][Hide abstract] ABSTRACT: This paper presents the innovative electronic medical record based stroke registry system (SRS) that has been designed and developed at Chang Gung Memorial Hospital (CGMH). A prototype which was introduced in 2006, akin to a consumer electronics commodity, has been adopted by other vascular disease-associated specialties such as cardiology, endocrinology, nephrology and oncology. Furthermore, the SRS has proliferated to three other hospitals within the CGMH chain and promises to provide longitudinal association between pathophysiology and clinical outcomes of vascular diseases in the Taiwanese population.
[Show abstract][Hide abstract] ABSTRACT: Cerebral hypoperfusion is responsible for cognitive impairment in patients with severe carotid artery stenosis (CAS). The manifestation of reversed ophthalmic artery flow (ROAF) is not uncommon in patients with CAS, suggesting a state of intensified cerebral hypoperfusion. This study aimed to examine whether the presence of ROAF can exacerbate cognitive impairment in patients with severe unilateral CAS.
One-hundred-and-two patients with CAS and 37 age-matched volunteers participated in this case-control study. Depending on the side of CAS and occurrences of ROAF, the patients were allocated to four groups: left CAS groups with ROAF (n=28) or without ROAF (n=22), and right CAS groups with ROAF (n=26) or without ROAF (n=26). All subjects underwent a battery of neuropsychological tests.
All patients performed worse than the control group on most tests. No significant differences were observed between patient groups (ps>0.05), except for inferior performance on psychomotor speed and visuospatial tests in the right ROAF group (ps<0.03). Hierarchical regression analyses indicated strong contributions of estimated premorbid intelligence to performance on most tests (ps<0.05). The severity of left and right CAS was distinctively associated with different functions. To a lesser extent, the severity of infarcts was also associated with impairment of psychomotor speed and some executive functions (ps<0.05). The contributions of ROAF to performance on most tests were negligible.
Patients with unilateral CAS may present with specific cognitive impairment relevant to the ipsilateral hemispheric functions. However, the manifestation of ROAF does not necessarily imply more extensive or severe cognitive impairment.
Full-text · Article · Oct 2013 · Journal of the neurological sciences
[Show abstract][Hide abstract] ABSTRACT: Cerebral vasoreactivity (CVR) can be assessed by functional MRI (fMRI) using hypercapnia challenges. In normal subjects, studies have shown temporal variability of CVR blood oxygenation level-dependent responses among different brain regions. In the current study, we analyzed the variability of BOLD CVR dynamics by fMRI with a breath-holding task in 17 subjects with unilateral carotid stenosis before they received carotid stenting. Great heterogeneity of CVR dynamics was observed when comparing BOLD responses between ipsilateral and contralateral hemispheres in each patient, especially in middle cerebral artery (MCA) territories. While some subjects (n=12) had similar CVR responses between either hemisphere, the others (n=5) had a poorly correlated pattern of BOLD changes between ipsilateral and contralateral hemispheres. In the latter group, defined as impaired CVR, post-stenting perfusion tended to be more significantly increased. Our data provides the first observation of divergent temporal BOLD responses during breath holding in patients with carotid stenosis. The development of collateral circulation and the derangement of cerebral hemodynamics can be detected through this novel analysis of the different patterns of BOLD changes. The results also help in prediction of robust increase of perfusion or hyperperfusion after carotid stenting.
[Show abstract][Hide abstract] ABSTRACT: We aimed to assess whether intracranial carotid artery calcification (ICAC) evident on head computed tomography is a risk factor for symptomatic intracerebral hemorrhage (sICH) following tissue plasminogen activator (tPA) treatment for acute stroke.
We classified 297 consecutive patients into 2 groups (no to mild ICAC and moderate to severe ICAC) according to ICAC severity. Outcome measures included detection of intracerebral hemorrhage and assessment using a modified Rankin scale (mRS) at 1 month and 1 year after stroke.
ICH (any type) was significantly more common in patients with moderate to severe ICAC than in patients with no to mild ICAC (22.5% versus 12%; relative risk [RR], 1.67; 95% confidence interval [CI], 1.1-2.5; P < .05). The moderate to severe ICAC group tended to have a higher percentage of sICH, but this association was not statistically significant (RR, 1.57; 95% CI, .75-3.3, P > .05). Multivariate adjusted regression analysis revealed that moderate to severe ICAC was an independent risk factor for ICH following tPA treatment (odds ratio, 2.52; 95% CI, 1.07-5.94; P = .04). Dependent functional outcome (mRS score 3-6) at 1-month and 1-year follow-up was significantly associated with moderate to severe ICAC (RR, 1.56; 95% CI, 1.06-2.27; and RR, 1.56; 95% CI, 1.06-2.33; P < .05). However, ICAC was not an independent factor of functional dependency at 1-month and 1-year follow-up in the final multivariate regression model.
A significantly higher percentage of patients with moderate to severe ICAC developed ICH following tPA administration for stroke. ICAC severity is an independent risk factor for ICH events. ICAC severity can help predict short-term and long-term functional dependency in tPA-treated patients, although this can be confounded by other cardiovascular risk factors and stroke severity.
No preview · Article · Jun 2013 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association
[Show abstract][Hide abstract] ABSTRACT: Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor encephalitis is an anti-neuronal surface antigen autoimmune encephalitis that is rarely reported. Our study evaluated the first known patient who developed anti-AMPA receptor encephalitis during pregnancy. Initial brain MRI revealed bilateral limbic encephalitis. However, rapid brain atrophy on MRI with extensive hypometabolism of cerebral cortices, caudate nuclei and brain stem hypoperfusion on (18)F-FDG PET developed when clinically progressed. IgG index of serial CSF studies reflected the clinical improvements after plasmapheresis and plasma exchange. The clinical spectrum of anti-AMPA receptor encephalitis may be expanded from limited limbic involvement to extended central nervous system.
Full-text · Article · Jun 2013 · Journal of neuroimmunology
[Show abstract][Hide abstract] ABSTRACT: Healthcare expenditure in many developed countries has reached such an unprecedented level that it cannot be sustainable unless some change in medical practice is implemented. In this paper, we examine a computer-in-the-loop model for the transaction between care-providers and care-receivers by identifying tasks that can be offloaded from physicians to computers in light of the state of the art of computer technology, as well as its evolution with time. Currently a number of consumer electronics innovations have found their way into healthcare applications. We anticipate that healthcare will be continuously benefited by such a trend.
[Show abstract][Hide abstract] ABSTRACT: The clinical analyses and prognoses of mitochondrial diseases with A3243G mutation are rarely documented in Taiwan. Our study investigated the clinical phenotypes and the outcomes of patients with mitochondrial disease and the A3243G mutation of mtDNA in a Taiwanese population, and compared these with previous reports. We retrospectively studied 22 consecutive patients with mitochondrial disease and the A3243G mutation of mtDNA in Chang Gung Memorial Hospital between 1988 and 2009. All patients underwent a detailed demographic registration, neurological examinations, a muscle biopsy, and mitochondrial DNA analysis. Modified Rankin scale, the presence of recurrent strokes or seizures, critical medical complications, and death were monitored during the follow-up period. Of the 22 patients, seizures and stroke-like episodes were found in 12 (55%). Visceral involvement, including cardiomyopathy, nephropathy, and pulmonary hypertension, were noted in five patients (23%). Patients with seizures had a high frequency of status epilepticus (92%) and a younger age of onset (21.3±7.2 years). Both the Kaplan-Meier survival analysis and the Cox-regression model showed a marked deterioration in patients with seizures after 7 years of follow-up.
Our study found that seizures and status epilepticus are the most important predictive values for a poor outcome in patients with the mtA3243G mutation of mtDNA. Age of onset and visceral organ involvement had no prominent influence on the prognosis. Some medical complications could be well controlled or even reversed after management.
Full-text · Article · Sep 2012 · Journal of the Formosan Medical Association
[Show abstract][Hide abstract] ABSTRACT: We wanted to examine whether brain computed tomography (CT) perfusion can help to detect the reconstitution of cerebral hemodynamics and predict intracerebral hemorrhage (ICH) after carotid stenting.
From September 2002 to October 2009, data of 114 patients with carotid intervention were prospectively collected, and we retrospectively identified a total of 108 consecutive patients with unilateral carotid stenting. Brain CT perfusion was studied at three time points: 1 week before, and 1 week and 6 months after stenting. Cerebral blood volume (CBV), cerebral blood flow, and time to peak (TTP) of brain CT perfusion were examined at cortical and subcortical areas of middle cerebral artery (MCA) and posterior cerebral artery territory. The CBV, cerebral blood flow, and TTP ratios of stenting side/nonstenting side were used for comparison. The flow direction of ophthalmic artery was detected by sonography, and the presence of anterior communicating artery was examined on prestenting cerebral angiogram.
After carotid stenting, CBV and TTP ratios improved significantly in both MCA cortical and subcortical areas in patients with unilateral carotid stenosis (P < .01) but not in patients with bilateral carotid stenosis. Patients with reversed ophthalmic flow had better improvement of TTP in both MCA and posterior cerebral artery territories (P < .05) than patients with forward flow. However, no significant difference was found between patients with and patients without anterior communicating artery collateral (P > .05). The prestenting TTP ratio in MCA subcortical area was significantly higher in patients with poststenting ICH than patients without ICH (P = .0191).
Cerebral hemodynamics can be reconstituted within a few days after carotid revascularization, especially in patients with reversed ophthalmic flow. Prolonged TTP in prestenting MCA subcortical area may suggest a high risk of poststenting ICH.
Preview · Article · Jul 2012 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
[Show abstract][Hide abstract] ABSTRACT: Animal studies have shown that cerebral hypoperfusion may be associated with amyloid plaque accumulation. Amyloid plaque is known to be associated with dementia and [(18)F]AV-45 is a positron emission tomography (PET) ligand that binds to extracelluar plaques. We hypothesized that demented patients with cerebral hypoperfusion may have increased [(18)F]AV-45 uptake. Five demented patients with cerebral hypoperfusion due to unilateral carotid artery stenosis (CAS) were examined with [(18)F]AV-45 PET, and the results were compared with six elderly controls. The standard uptake value ratio (SUVR) of each region of interest (ROI) was created using whole cerebellum as the reference region. All subjects underwent magnetic resonance imaging (MRI) for obtaining structural information. Patients with dementia and unilateral CAS had a higher global [(18)F]AV-45 SUVR (1.34 ± 0.06) as compared with controls (1.10 ± 0.04, p=0.0043), especially over the frontal, temporal, precuneus, anterior cingulate and occipital regions. The statistical distribution maps revealed a significantly increased [(18)F]AV-45 SUVR in the medial frontal, caudate, thalamus, posterior cingulate, occipital and middle and superior temporal regions ipsilateral to the side of CAS (p<0.01). The present study found that cerebral [(18)F]AV-45 binding is increased in demented patients with CAS, and its distribution is lateralized to the CAS side, suggesting that amyloid-related dementia may occur under cerebral hypoperfusion.
No preview · Article · May 2012 · Journal of the neurological sciences
[Show abstract][Hide abstract] ABSTRACT: A number of risk factors for early worsening of neurological symptoms have been identified. We aimed to evaluate the influence of hemorheologic, biochemical, and metabolic factors on neurological deterioration during hospitalization following acute ischemic stroke and develop a model of neurological deterioration.
Worsening of stroke was defined as a deleterious increase in NIH Stroke Scale (NIHSS) score of ≥4 points during hospitalization. We performed multivariate logistic regression analysis and constructed a prediction model based on chart data of 2,398 patients admitted at five medical centers; 203 of the patients had worsening of stroke and 2,186 had not.
The results of multivariate logistic regression analysis showed that hemoglobin (odds ratio: 0.529) and albumin (odds ratio: 0.024) were significantly associated with stroke deterioration, as were the modified Rankin Scale on emergency department admission (odds ratio: 4.956) and length of hospitalization (odds ratio: 1.201). After adjusting for age, gender and NIHSS on emergency department admission, only hemoglobin (odds ratio: 0.894, 95% confidence interval: 0.814-0.981, p = 0.018) was associated with worsening.
Hemoglobin and albumin were found to be risk factors for persistent neurological deterioration during hospitalization following acute ischemic stroke, suggesting that blood viscosity may be related to neurological deterioration.
No preview · Article · Feb 2012 · European Neurology
[Show abstract][Hide abstract] ABSTRACT: Clinical research of cervicocranial fibromuscular dysplasia (FMD) is rare in Asian populations. Our study reviewed Taiwanese ischemic stroke patients with cervicocranial FMD and compared them with previous reports.
Between 2000 and 2011, we collected 19 consecutive cervicocranial FMD patients who received demographic registration, a blood test for excluding vasculitis, and comprehensive angiography. Cerebral ultrasound, vascular images and clinical outcomes (Barthel index, modified Rankin scale, recurrent stroke, or death) were monitored during follow-up.
Of the 19 patients, 16 (84%) had carotid FMD, while 7 (37%) had vertebral FMD. Only 2 investigated patients (13%) had renal FMD and 1 (5%) had cerebral aneurysm. 14 (74%) presented acute arterial dissection. All patients received medical treatment and had neither recurrent stroke nor dissection during follow-up. In the literature review of 225 FMD patients, 3.6% had recurrent stroke during follow-up, and some reported surgical procedure or angioplasty could give a good clinical outcome in progressing ischemia irrelevant to the cause of stenosis.
In Taiwanese cervicocranial FMD patients, arterial dissection was one of the most common clinical presentations. Most of our patients had isolated involvement of the cervicocranial artery and carried a favorable outcome under medical treatment.
Full-text · Article · Jan 2012 · European Neurology
[Show abstract][Hide abstract] ABSTRACT: The occurrence of silent ischemic lesions (SILs) is a common finding after carotid artery stenting (CAS). This study aimed to evaluate the impact of SILs on cognitive functioning following CAS.
The retrospective study separated 131 patients with unilateral carotid stenosis into three groups: medication only, MRI-evaluated CAS and CT-evaluated CAS, and compared the sociodemographic factors, post-CAS images and Mini-Mental State Examination scores performed before and 6-12 months after enrollment.
Seven minor strokes occurred in the 99 patients receiving CAS. SILs were detected in 12 of 55 patients with diffusion-weighted MR imaging (DWI) and in 3 of 37 patients with CT 1 week after CAS. In patients with DWI follow-up, the frequency of SILs was 8, 24, 43 and 60% in patients with 0-, 1-, 2- and 3-vessel coronary artery disease (p = 0.006). The frequency of SILs on DWI was 0, 32 and 33% in patients with improved, unchanged, or deteriorated cognitive functioning (p = 0.02). Such an association was not observed if based on SILs on CT or manifesting stroke.
The presence of coronary artery disease increases the risk for having post-CAS SILs, and the occurrence of SILs may be associated with cognitive changes after CAS.
No preview · Article · Nov 2011 · European Neurology
[Show abstract][Hide abstract] ABSTRACT: We explored the role of variants of the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene as factors for atherothrombotic stroke (ATS). A HapMap-based haplotype-tagging single nucleotide polymorphism (htSNP) association study was conducted in an isolated Taiwanese population. Multivariate logistic regression analyses revealed that patients with the GG/CG genotype of rs4293222 and the AA/AG genotype of rs4360791 had a 1.61-fold (odds ratio [OR]=1.61; 95% confidence interval [CI]=1.02-2.56, p=0.042) and a 1.69-fold (OR=1.69; 95% CI=1.00-2.86, p=0.047) increased risk of ATS, compared with patients with the CC/GG genotype, respectively. The most common haplotype allele, GTA, was used as a reference when analyzing the association between the haplotypes related to rs4293222, rs10507391, rs12429692 and ATS. The combined frequencies of all minor variant alleles of the three selected htSNP were associated with a 44% decreased risk of ATS (OR=0.56; 95% CI=0.37-0.84, p=0.005). This study provides preliminary evidence suggesting that genetic polymorphisms of ALOX5AP are associated with ATS.
No preview · Article · Nov 2011 · Journal of Clinical Neuroscience
[Show abstract][Hide abstract] ABSTRACT: Leukoaraiosis (LA) affects cognition after stroke and reversal of LA may improve cognitive performance. We aimed to determine the impact of cerebral perfusion and circle of Willis (CoW) flow patterns on the extent of LA after carotid artery revascularization.
LA was scored on fluid-attenuated inversion recovery magnetic resonance (MR) images at the levels of the centrum semiovale and frontal horns in both cerebral hemispheres of 62 contiguous patients (men/women = 38/24, mean age = 63.2 ± 8.4 years, range 44-82) before and after unilateral carotid artery revascularization. The pre- and poststenting differences in LA scores, CoW flow pattern on MR angiography, and MR perfusion parameters were analyzed.
The total LA score decreased from 9.87 ± 0.65 to 8.33 ± 0.72 after stenting (p = 0.03). The CoW was complete in 21 subjects and incomplete in 41 subjects. The incomplete CoW group had a higher preoperative LA load and higher cerebral interhemispheric asymmetry index, both of which decreased significantly postoperatively.
CoW anomalies may contribute to LA in patients with carotid artery stenosis, and restoration of cerebral perfusion by carotid artery revascularization can reduce LA severity.
No preview · Article · Nov 2011 · Cerebrovascular Diseases