Shan-Jin Ryu

Predictors of carotid artery stenosis after radiotherapy for head and neck cancers

OBJECTIVE To study the prevalence of and risk factors associated with carotid artery stenosis (CAS) after radiotherapy (RT) for head and neck cancer. METHODS DESIGN OF STUDY Prospective, cross-sectional study. SETTING Patients recruited from a hospital Radiation-Oncology department. SUBJECTS From March 2002 to August 2006, 290 consecutive head and neck cancer patients were enrolled in this study. One hundred ninety-two of these patients had previously undergone RT (RT group) and 98 had no RT (control group). INTERVENTION After detecting CAS by carotid duplex sonography, the severity of CAS was evaluated by a bilateral plaque scoring system. MAIN OUTCOME MEASURE CAS score. RESULTS There were no differences in age or gender between the two groups. The RT group had a significantly higher plaque score than the non-irradiated group (P < .05). Multiple regression analysis of the 290 head and neck cancer patients revealed that bilateral plaque score was significantly correlated with age, hyperlipidemia, and RT. Multiple regression analysis was performed in the RT group alone with patients 41-50 years old serving as the reference group. This analysis showed that in RT patients > 50 years old, age was inversely correlated with plaque score; however, in RT patients <or= 41 years old, age was positively correlated with plaque score. CONCLUSION In head and neck cancer, the high post-treatment incidence of radiation-induced CAS indicates the importance of regular examination of the carotid duplex and early antiplatelet prophylaxis. Different age groups may require different irradiation strategies to prevent radiation-induced CAS.

Dose Titration to Reduce Dipyridamole-Related Headache

Background: Combination of low-dose aspirin and modified-release dipyridamole (ASA+MR-DP) provides a significantly increased benefit in stroke prevention over aspirin alone. However, headaches were reported in more patients receiving dipyridamole-containing agents than in those receiving placebo. We undertook a randomized, double-blind, placebo-controlled trial to evaluate which dosing regimens of ASA+MR-DP have better tolerance. Methods: This trial randomized 146 patients with a history of ischemic cerebrovascular disease into three groups: placebo (days 1–28), reduced dose (placebo on days 1–4, ASA+MR-DP once daily before bed during days 5–14, and b.i.d. on days 15–28), and regular dose (placebo on days 1–4, and ASA+MR-DP b.i.d. on days 5–28). Using Chinese diary card, headache was assessed as mean cumulated headache (Σ frequency × intensity/occurrence days × study days) over the study period, and was graded 0–4 according to Cancer Therapy Evaluation Program, Common Toxicity Criteria, Version 2.0. Results: Intent-to-treat patients after randomization was 46 in placebo group, 45, reduced dose, and 49, regular dose. Among commonly reported adverse effects, headache of any grade occurred significantly more in the regular dose group (38.8%), as compared to the other two groups (p < 0.05). Mean cumulated headache was higher (p < 0.05) in the regular dose group than in the reduced group during days 5–14. Of 27 patients who dropped out, 15 (55.6%) were due to headache, which was substantially more in regular dose (8, 53.3%), though the difference was statistically insignificant. Conclusions: Initial reduced dose treatment with ASA+MR-DP may cause fewer headaches than regular dosing, and seems better tolerated by those susceptible to phosphodiesterase inhibitor-induced headache.

Cerebral hemodynamic responses to betel chewing: a Doppler study.

We sought to evaluate cerebral hemodynamic responses to betel chewing. Thirty healthy male volunteers (mean age = 35 years), ten new chewers, ten occasional chewers, and ten chronic chewers were included in this study. We used carotid duplex sonography and transcranial Doppler to measure the flow velocities and flow volume (FV) of the common carotid (CCA), internal carotid (ICA), external carotid (ECA) arteries, and the flow velocity of middle cerebral artery (MCA). Blood pressure (BP) and heart rate (HR) were recorded simultaneously. All subjects were asked to chew fruit-flavored chewing gum for 10 minutes. Blood flows of the above vessels were measured four times at baseline and at the 2nd, 6th, and 12th minute after chewing. A repeated study was followed in the same subject but substituted with betel nut. Chronic chewers had delayed onset time and shortened vanishing time of facial-flushing sensation. Systolic and diastolic BPs were mildly elevated during gum chewing (p = 0.008 and 0.015, respectively), whereas diastolic BP was dropped during betel chewing (p = 0.008). Heart rate increased prominently during betel chewing (p < 0.0001), especially in new and occasional chewers. The peak systolic, end diastolic velocities, and FV in ECA and CCA increased significantly during betel chewing (p < 0.0001). The blood flows in the ICA and MCA had no significant changes during gum or betel chewing. Betel chewing has a central sympathetic effect resulting in accelerated HR, increased blood flows in ECA and CCA, but has a peripheral cholinergic effect resulting in a drop of diastolic BP. Intracranial cerebral hemodynamics is not affected during betel chewing. The inotropic and chronotropic effect to the heart from betel chewing is probably an unfavorable risk for patients with ischemic heart disease.

Dehydration is an independent predictor of discharge outcome and admission cost in acute ischaemic stroke

Our aim was to investigate the influence of admission dehydration on the discharge outcome in acute ischaemic and hemorrhagic stroke.

Carotid floating plaques associated with multiple cerebral embolic strokes. Case reports.

The authors describe 2 patients with multiple cerebral infarcts and hemorrhagic trans formation caused by artery-to-artery emboli. Ulcerated plaques with free-floating thrombus adherent to the plaque were detected at the carotid bifurcation by duplex sonography. No other embolic source could be found. One patient developed an occipital infarction due to carotid emboli passing through a fetal-type posterior communicating artery. Both patients recovered well without recurrence of stroke or transient ischemic attack with antiplatelet treatment only. Follow-up carotid duplex sonography showed disappearance of floating thrombus in 1 patient and consolidation of the lesion in the other.

Impact of silent ischemic lesions on cognition following carotid artery stenting.

Objective: 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. Methods: 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. Results: 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. Conclusion: 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.

ALOX5AP genetic variants and risk of atherothrombotic stroke in the Taiwanese population

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.

Fire-Heat and Qi Deficiency Syndromes as Predictors of Short-term Prognosis of Acute Ischemic Stroke

OBJECTIVES To explore the relationships between traditional Chinese medicine (TCM) syndromes and disease severity and prognoses after ischemic stroke, such as neurologic deficits and decline in activities of daily living (ADLs). METHODS The study included 211 patients who met the inclusion criteria of acute ischemic stroke based on clinical manifestations, computed tomography or magnetic resonance imaging findings, and onset of ischemic stroke within 72 hours with clear consciousness. To assess neurologic function and ADLs in patients with different TCM syndromes, the TCM Syndrome Differentiation Diagnostic Criteria for Apoplexy scale (containing assessments of wind, phlegm, blood stasis, fire-heat, qi deficiency, and yin deficiency with yang hyperactivity syndromes) was used within 72 hours of stroke onset, and Western medicine-based National Institutes of Health Stroke Scale (NIHSS) and Barthel Index (BI) assessments were performed at both admission and discharge. RESULTS The most frequent TCM syndromes associated with acute ischemic stroke were wind syndrome, phlegm syndrome, and blood stasis syndrome. Improvement according to the BI at discharge and days of admission were significantly different between patients with and those without fire-heat syndrome. Patients with qi deficiency syndrome had longer hospital stays and worse NIHSS and BI assessments at discharge than patients without qi deficiency syndrome. All the reported differences reached statistical significance. CONCLUSIONS These results provide evidence that fire-heat syndrome and qi deficiency syndrome are essential elements that can predict short-term prognosis of acute ischemic stroke.

Genetic polymorphisms of low density lipoprotein receptor can modify stroke presentation.

Abstract Low density lipoprotein is transcytosed across the blood–brain barrier mediated by low density lipoprotein receptor (LDLR). LDLR in the brain is mainly expressed on capillary endothelial cells and is therefore considered to be an important susceptibility gene in modifying the stroke presentation. A HapMap-based haplotype-tagging single nucleotide polymorphism association study was conducted in an isolated Taiwanese population. Two hundred and ninety-two unrelated patients with cerebral infarction, 76 patients with small vessel occlusion (SVO) disorder and 216 with non-SVO disorder were enrolled. For rs2738446, under the dominant model, the odds ratios (ORs) associated with the CC genotype were computed, with GG + CG carriers considered as the reference group. Homozygote CC carriers had a two-fold increased risk of SVO disorder [OR=2·0, 95% confidence interval (CI)=1·08–3.70, p=0·025). For rs2738450, under the dominant model, the ORs associated with the CC genotype were computed, with AA + AC carriers considered as the reference group. Homozygote CC carriers had a 1·85-fold increased risk of SVO disorder (OR=1·85, 95% CI=1·01–3.33, p=0·04). When analysing the association between the haplotype related to rs2738446 and rs2738450 and SVO disorder, the most common haplotype allele CC was used as the reference, and the GA haplotype allele was associated with a 48% decreased risk of SVO disorder (OR=0·52; 95% CI=0·29–0.93, p=0·029). Haplotype-based analysis of LDLR in Taiwanese patients with cerebral infarction provided preliminary evidence suggesting that genetic polymorphisms of LDLR can modify the stroke presentation.

Carotid Ultrasound Criteria for Detecting Intracranial Carotid Stenosis

Background/Aims: This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA). Methods: Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA ≧50% stenosis were calculated. Results: The criteria identified for detecting intracranial ICA ≧50% stenosis were ICA FV <159 ml/min, ICA PSV <33 cm/s and CCA PSV <42 cm/s. When ICA PSV <33 cm/s was combined with CCA PSV <42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA ≧50% stenosis were CCA FV <285 ml/min, ICA FV <179 ml/min, ICA PSV <33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity. Conclusion: This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.