Multidisciplinary approach to Fibromyalgia: What are we learning from updated evidence-based medicine?

Fibromyalgia (FM) is a disease characterized by amplified pain responses; here, hyperalgesia occurs in response to noxious stimuli, and allodynia occurs in response to non-noxious stimuli. The diagnosis of FM is often time consuming because it overlaps with psychosomatic symptoms. Indeed, most cases of FM are combined with other comorbidities, such as rheumatological diseases, mental disorders, or gastrointestinal disorders. The main symptoms of FM, which include pain, fatigue, and sleep disturbance, are poorly discriminatory and, thus, greatly increase the difficulty of diagnosis. The 2017 European League Against Rheumatism treatment guidelines of FM recommend that non-pharmacological therapies based on exercise should first be attempted after a diagnosis of FM. Although drug treatments appear to be effective, evidence supporting the use of this treatment modality is relatively weak. Obtaining a broad understanding of FM can help clinicians formulate individualized treatment to improve patient functions and quality of life. Key words: fibromyalgia, diagnostic criteria, non-pharmacological therapy.

Early Rehabilitation after Acute Stroke:The Golden Recovery Period.

Stroke is a leading cause of disability worldwide. Neuroplasticity, a condition wherein the brain's dynamic response to injury is heightened and rehabilitation might be effective, is observed shortly after acute stroke. However, although several trials have demonstrated that initiating treatment within 24 hours after stroke is potentially harmful, some have shown that early rehabilitation of patients is beneficial. Administration of constraint-induced movement therapy within two weeks after stroke appears to be beneficial for the upper extremities. In addition, intensive early post-stroke therapy may be beneficial for patients with severe aphasia. Novel approaches to early treatment of post-stroke dysphagia appear promising; however, the high rate of spontaneous improvement makes it difficult to gauge their benefits. Overall, although increasing evidence indicates that initiating rehabilitative strategies within two weeks after stroke is beneficial for some deficits, the optimal time for initiating post-stroke rehabilitation remains undetermined. Keywords: stroke, early rehabilitation, neuroplasticity, early mobilization.

Urgent Demand of Network Access for Acute Ischemic Stroke Management in Taiwan.

Time is the major determinant in successful reperfusion therapy of acute ischemic stroke. The evolving diagnostic tools and treatment of acute stroke has made a great progress in the past 2 decades and is remolding current management practices. It demands a timely neurologic evaluation and a neuroimaging study to determine if stroke patients are appropriate candidates for reperfusion demands. Therefore, it is critical for the setting of stroke center accreditation levels and capabilities so that timely and appropriate treatment is initiated for the eligible stroke patients. Optimal acute ischemic stroke treatment requires all levels of stroke center network operating efficiently. In the future, Taiwan should revise the criteria of stroke center accreditation and set up the efficient acute stroke treatment network as soon as possible. Keywords: stroke, reperfusion, intra-arterial thrombectomy, intravenous recombinant tissue plasminogen activator.

Biomarkers with Plasma Amyloid ß and Tau Protein Assayed by Immunomagnetic Reduction in Patients with Amnestic Mild Cognitive Impairment and Alzheimer's Disease.

This review addresses recent developments in the analyses of plasma amyloid beta (Aß) and total tau (t-tau) protein levels as biomarkers for discriminating amnestic mild cognitive impairment (aMCI) from Alzheimer disease (AD), using immunomagnetic reduction (IMR). Recent studies have focused on the differential diagnosis of normal controls (NCs) with aMCI or AD. Results of 15 clinical studies have demonstrated decrease in plasma Aß1-40 and increase in plasma Aß1-42 and t-tau levels in patients with aMCI and AD. For a given biomarker, effect size is determined by comparing the mean ratios of biomarker levels between two diagnostic groups. Effect sizes are less than 1 for Aß1-40 (0.606-1.032) but >1 for Aß1-42 (1.018-2.167) and t-tau (1.030-4.147) in aMCI and AD compared with NCs. The effect size of the plasma tau significantly increases the most as aMCI progresses to AD. Studies into the application of IMR to determine plasma Aß and tau levels as biomarkers for aMCI or AD have recently progressed. Future investigations should validate recently published results, preferably in patients with pathologically confirmed AD. In addition, effort should be directed toward standardizing the design of such studies and data analysis. Keywords: amyloid beta, plasma tau, Alzheimer disease, biomarker, mild cognitive impairment.

Mathematical Framework of Deconvolution Algorithms for Quantification of Perfusion Parameters.

PURPOSE: MR perfusion weighted imaging (PWI) has been used as sensitive indicator of tissue at risk for infarction. Quantitative perfusion parameters such as cerebral blood flow (CBF), mean transit time (MTT) and cerebral blood volume (CBV) can be obtained from post processing of PWI data using standard singular value decomposition algorithm (SVD). Assumption regarding absence of arterial - tissue delay (ATD) used in SVD algorithm results in underestimation of perfusion parameters. To estimate accurate values for perfusion parameters it is important to understand the mathematical framework behind SVD and improved SVD algorithms (bSVD and rSVD). METHOD: This study explains the mathematical framework of SVD and improved SVD algorithms and uses computational techniques that use bSVD algorithm to obtain perfusion parameters maps of CBF, CBV and MTT for acute stroke patient. RESULT: Computational techniques based on mathematical deconvolution algorithms are used to post process CBV, CBF and MTT maps where decrease in CBF and CBV were seen in left hemisphere. CONCLUSION: The bSVD algorithm is found to be sensitive to ATD and provides more accurate estimates of perfusion parameters than the SVD algorithm, however CBF estimates from bSVD and rSVD still remain influenced by other artifacts Keywords: PWI = perfusion weighted imaging, CBF= cerebral blood flow, MTT = mean transit time, CBV= cerebral blood volume, SVD = singular value decomposition algorithm.

Valproate is protective against 6-OHDA-induced dopaminergic neurodegeneration in rodent midbrain: A potential role of BDNF up-regulation.

BACKGROUND/PURPOSE: The main purpose of this study was to extend previously reported showing potent neuroprotective effect of valproic acid (VPA) in primary midbrain neuro-glial cultures to investigate whether VPA could protect dopamine (DA) neurons in vivo against 6-hydroxydopamine (6-OHDA)-induced neurodegeneration and to determine the underlying mechanism. METHODS: Male adult rats received a daily intraperitoneal injection of VPA or saline for two weeks before and after injection of 5, 10, or 15 µg of 6-OHDA into the brain. All rats were evaluated for motor function by rotarod performance. Brain samples were prepared for immunohistochemical staining and for determination of levels of dopamine, dopamine metabolites, and neurotrophic factors. RESULTS: 6-OHDA injection showed significant and dose-dependent damage of dopaminergic neurons and decrease of striatal dopamine content. Rats in the VPA-treated group were markedly protected from the loss of dopaminergic neurons and showed improvements in motor performance, compared to the control group at the moderate 6-OHDA dose (10 µg). VPA-treated rats also showed significantly increased brain-derived neurotrophic factor (BDNF) levels in the striatum and substantia nigra compared to the levels in control animals. CONCLUSION: Our studies demonstrate that VPA exerts neuroprotective effects in a rat model of 6-OHDA-induced Parkinson's disease (PD), likely in part by up-regulation BDNF.

Changes in sensorimotor-related thalamic diffusion properties and cerebrospinal fluid hydrodynamics predict gait responses to tap test in idiopathic normal-pressure hydrocephalus.

OBJECTIVES: To compare diffusion tensor (DT)-derived indices from the thalamic nuclei and cerebrospinal fluid (CSF) hydrodynamic parameters for the prediction of gait responsiveness to the CSF tap test in early iNPH patients. METHODS: In this study, 22 patients with iNPH and 16 normal controls were enrolled with the approval of an institutional review board. DT imaging and phase-contrast magnetic resonance imaging were performed in patients and controls to determine DT-related indices of the sensorimotor-related thalamic nuclei and CSF hydrodynamics. Gait performance was assessed in patients using gait scale before and after the tap test. The Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were applied to compare group differences between patients and controls and assess the predictive performance of gait responsiveness to the tap test in the patients. RESULTS: Fractional anisotropy (FA) and axial diffusivity showed significant increases in the ventrolateral (VL) and ventroposterolateral (VPL) nuclei of the iNPH group compared with those of the control group (p < 0.05). The predictions of gait responsiveness of ventral thalamic FA alone (area under the ROC curve [AUC] < 0.8) significantly outperformed those of CSF hydrodynamics alone (AUC < 0.6). The AUC curve was elevated to 0.812 when the CSF peak systolic velocity and FA value were combined for the VPL nucleus, yielding the highest sensitivity (0.769) and specificity (0.778) to predict gait responses. CONCLUSIONS: Combined measurements of sensorimotor-related thalamic FA and CSF hydrodynamics can provide potential biomarkers for gait response to the CSF tap test in patients with iNPH. KEY POINTS: • Ventrolateral and ventroposterolateral thalamic FA may predict gait responsiveness to tap test. • Thalamic neuroplasticity can be assessed through DTI in idiopathic normal-pressure hydrocephalus. • Changes in the CST associated with gait control could trigger thalamic neuroplasticity. • Activities of sensorimotor-related circuits could alter in patients with gait disturbance. • Management of patients with iNPH could be more appropriate.

Associations of estradiol levels and genetic polymorphisms of inflammatory genes with the risk of ischemic stroke.

BACKGROUND: Estrogen plays an important role as an anti-inflammatory and neuroprotective agent in ischemic stroke. In this study, we analyzed the effect of a polygenic risk score (PRS) constructed using inflammatory genes and estradiol levels on the risk of ischemic stroke. METHODS: This case-control study was conducted with 624 ischemic stroke patients and 624 age- and gender-matched controls. The PRS estimated the polygenic contribution of inflammatory genes from ischemic stroke susceptibility loci. Estradiol levels were measured using a radioimmunoassay. High and low estradiol levels were defined according to the log-transformed median estradiol levels in female and male controls. RESULTS: Subjects in the fourth quartile of the PRS had a significant 1.57-fold risk of ischemic stroke (95% confidence interval [CI], 1.12 ~ 2.19), after adjusting for covariates compared to individuals in the lowest quartile. Compared to individuals with high estradiol levels and a low PRS as the reference group, those exposed to low estradiol levels and a high PRS had an increased risk of ischemic stroke (odds ratio, 3.35; 95% CI, 1.79 ~ 6.28). Similar results were also observed in males when the analysis was stratified by gender. CONCLUSIONS: Our data suggest that the PRS can be useful in evaluating a high risk of ischemic stroke among patients, especially those exposed to low estradiol levels.

Usefulness of glycated hemoglobin A1c-based adjusted glycemic variables in diabetic patients presenting with acute ischemic stroke.

Acute hyperglycemia is a common condition among patients with diabetes who are admitted to the emergency department (ED) for acute ischemic stroke (AIS). Previous findings regarding the association between hyperglycemia at admission and adverse outcomes among patients with diabetes and AIS have been inconsistent. When investigating this association, it is necessary to consider premorbid blood glucose control. The objective of the current study was to assess whether HbA1c-based adjusted glycemic variables were associated with unfavorable outcomes among patients admitted to the hospital for AIS. We retrospectively analyzed data from 309 patients who were hospitalized for AIS at a single medical center in Taiwan between January 1, 2013, and October 31, 2015. We found that 1) HbA1c-based adjusted glycemic variables, including the glycemic gap and stress hyperglycemia ratio, were associated with both AIS severity and neurological status at discharge; additionally, 2) HbA1c-based adjusted glycemic variables showed superior discriminative power compared with acute hyperglycemia regarding the development of severe AIS. We conclude that both the glycemic gap and stress hyperglycemia ratio might be useful in assessing the disease severity and prognosis of patients presenting with AIS. Further prospective long-term follow-up studies should be performed to validate these findings.

Homozygous ALDH2*2 Is an Independent Risk Factor for Ischemic Stroke in Taiwanese Men.

BACKGROUND AND PURPOSE: The *2 allele of the aldehyde dehydrogenase 2 gene (ALDH2) is the most common variant in Asian populations. The variant resulting in enzyme dysfunction was highly related to coronary artery disease. Recently, genome-wide association studies also discovered that the 12q24 locus near ALDH2 gene was associated with hypertension and ischemic stroke. This study intended to further investigate whether the above variant of ALDH2 increases the risk for ischemic stroke in Taiwanese. METHODS: A case-control study was conducted on 914 patients with acute ischemic stroke and 746 nonstroke controls. Polymerase chain reaction and sequencing were used to identify the ALDH2 genotype. Vascular risk factors, stroke subtypes, vascular stenosis, and stroke outcomes were analyzed. RESULTS: ALDH2 genotypes differed significantly between male controls (*1/*1 versus *1/*2 versus *2/*2=53.8% versus 39.9% versus 6.4%) and male patients with ischemic stroke (*1/*1 versus *1/*2 versus *2/*2=51.5% versus 37.3% versus 11.2%; P=0.048). No significant difference was found between groups for female patients (P=0.228). Multivariate logistic regression analysis revealed that the ALDH2*2/*2 genotype was an independent risk factor for ischemic stroke in male patients (odds ratio, 1.93 [95% confidence interval, 1.07-3.46]; P=0.028). Further analysis of men with ischemic stroke demonstrated that the polymorphism of ALDH2 was not related to vascular risk factors, severity of vascular atherosclerosis, stroke subtypes, and stroke functional outcomes. CONCLUSIONS: The study demonstrated that ALDH2*2/*2 may be an independent risk factor for ischemic stroke in Taiwanese men, but not in Taiwanese women.

ALDH2*2 but not ADH1B*2 is a causative variant gene allele for Asian alcohol flushing after a low-dose challenge: correlation of the pharmacokinetic and pharmacodynamic findings.

OBJECTIVE: It has been well documented that variant alleles of both ADH1B*2 of alcohol dehydrogenase (ADH) and ALDH2*2 of aldehyde dehydrogenase (ALDH) protect against the development of alcoholism in East Asians. However, it remains unclear whether ADH1B*2 contributes significantly toward the accumulation of systemic blood acetaldehyde and whether it plays a critical role in the alcohol flushing reaction. PARTICIPANTS AND METHODS: Sixty-one adult Han Chinese men were recruited and divided into six combinatorial genotypic groups: ALDH2*1/*1-ADH1B*1/*1 (12), ALDH2*1/*1-ADH1B*1/*2 (11), ALDH2*1/*1-ADH1B*2/*2 (11); ALDH2*1/*2-ADH1B*1/*1 (9), ALDH2*1/*2-ADH1B*1/*2 (9), and ALDH2*1/*2-ADH1B*2/*2 (9). After ingesting 0.3 g/kg of alcohol, blood ethanol, acetaldehyde, and acetate concentrations, as well as the facial skin blood flow (FSBF) and pulse rate were measured for 130 min. RESULTS: The ALDH2*1/*2 heterozygotes carrying three ADH1B allelotypes showed significantly higher peak levels and areas under the concentration curve (AUCs) of the blood acetaldehyde as well as significantly greater increases in the peak pulse rate and peak FSBF compared with the ALDH2*1/*1 homozygotes. However, no significant differences in peak levels and AUCs of blood ethanol, acetaldehyde or acetate, or the peak cardiovascular responses, were found between the ADH1B allelotypes carrying ALDH2*1/*1 or between those with ALDH2*1/*2. Partial correlation analyses showed that peak blood acetaldehyde, rather than the blood ethanol or acetate, was correlated significantly with the peak responses of pulse rate and FSBF. CONCLUSION: Findings indicate that ALDH2*2, rather than ADH1B2*2, is a causal variant allele for the accumulation of blood acetaldehyde and the resultant facial flushing during low alcohol consumption.

Association between plasma levels of hyaluronic acid and functional outcome in acute stroke patients.

BACKGROUND: Activation of hyaluronic acid (HA) and associated enzyme synthesis has been demonstrated in experimental stroke animal models. Our study aimed to investigate the plasma levels of HA in acute stroke patients and the associations between HA levels and functional outcome. METHODS: This was a multicenter case-control study. Acute stroke patients and age- and sex-matched non-stroke controls were recruited. Plasma levels of HA in acute stroke patients were determined at <48 hours and at 48 to 72 hours after stroke onset by standard ELISA. Favorable functional outcome was defined as modified Rankin scale ≤ 2 at 3 months after stroke. RESULTS: The study included 206 acute stroke patients, including 43 who had intracerebral hemorrhage and 163 who had ischemic stroke, and 159 controls. The plasma levels of HA in the acute stroke patients were significantly higher than those in the controls (219.7 ± 203.4 ng/ml for <48 hours and 343.1 ± 710.3 ng/ml for 48 to 72 hours versus 170.4 ± 127.9 ng/ml in the controls; both P < 0.05). For intracerebral hemorrhage patients, HA ≤ 500 ng/ml (<48 hours) was an independent favorable outcome predictor (P = 0.016). For ischemic stroke patients, an inverted U-shaped association between plasma HA (48 to 72 hours) and outcome was noted, indicating that ischemic stroke patients with too high or too low plasma HA levels tended to have an unfavorable outcome. CONCLUSION: HA plasma level was elevated in patients with acute stroke, and can predict 3-month functional outcome, particularly for patients with intracerebral hemorrhage.

Multiple sclerosis presenting initially with a worsening of migraine symptoms.

Multiple sclerosis (MS) is a chronic autoimmune disease that targets myelinated axons in the central nervous system. Headache has been reported as a subtle symptom of the onset of MS, with a variable frequency of 1.6-28.5%; however, it remains unclear whether headache is a true symptom of MS onset. Here, we report the case of a female patient who had a history of migraine without aura and experienced worsening of migraine-headache symptoms as the initial manifestation of MS. Three similar cases were reported previously; however, unlike this case, those cases had no history of migraine without aura. In our case, we excluded factors that could trigger migraine attacks, such as changes in weather, drugs, alcohol, caffeine withdrawal, stress, fatigue, lack of sleep, hormonal therapy, diet, and hunger. The patient had one episode of MS attack with the simultaneous presence of asymptomatic gadolinium-enhancing and non-enhancing lesions, including hyperintense lesions in the bilateral periventricular white matter, body of the corpus callosum, and periaqueductal grey matter, as observed on the T2-weighted images obtained at the first brain magnetic resonance imaging. In addition, after the injection of gadolinium contrast, ring enhancement over these lesions was noted in T1-weighted images, which was suggestive of active demyelination. MS was diagnosed according to the McDonald criteria (2010 revision). We conclude that MS with periaqueductal grey matter involvement may present with worsening migraine. It is important to be cautious if any secondary causes exist, especially when the patient has a history of migraine without aura. MS should be one of the differential diagnoses in young women showing a change in headache pattern or poor clinical drug response to migraine treatment accompanied by episodes of focal neurological deficit. Failure to recognize MS may lead to inappropriate treatment and worse prognosis; early diagnosis in patients with MS is essential to improve their clinical outcomes and quality of life.

Core and penumbra estimation using deep learning-based AIF in association with clinical measures in computed tomography perfusion (CTP).

OBJECTIVES: To investigate whether utilizing a convolutional neural network (CNN)-based arterial input function (AIF) improves the volumetric estimation of core and penumbra in association with clinical measures in stroke patients. METHODS: The study included 160 acute ischemic stroke patients (male = 87, female = 73, median age = 73 years) with approval from the institutional review board. The patients had undergone CTP imaging, NIHSS and ASPECTS grading. convolutional neural network (CNN) model was trained to fit a raw AIF curve to a gamma variate function. CNN AIF was utilized to estimate the core and penumbra volumes which were further validated with clinical scores. RESULTS: Penumbra estimated by CNN AIF correlated positively with the NIHSS score (r = 0.69; p < 0.001) and negatively with the ASPECTS (r = - 0.43; p < 0.001). The CNN AIF estimated penumbra and core volume matching the patient symptoms, typically in patients with higher NIHSS (> 20) and lower ASPECT score (< 5). In group analysis, the median CBF < 20%, CBF < 30%, rCBF < 38%, Tmax > 10 s, Tmax > 10 s volumes were statistically significantly higher (p < .05). CONCLUSIONS: With inclusion of the CNN AIF in perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke. CRITICAL RELEVANCE STATEMENT: With CNN AIF perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke.

The role of ALDH2 and ADH1B polymorphism in alcohol consumption and stroke in Han Chinese.

The genes encoding the enzymes for metabolising alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) - exhibit genetic polymorphism and ethnic variations. Although the ALDH2*2 variant allele has been widely accepted as protecting against the development of alcoholism in Asians, the association of the ADH1B*2 variant allele with drinking behaviour remains inconclusive. The goal of this study was to determine whether the polymorphic ADH1B and ALDH2 genes are associated with stroke in male Han Chinese with high alcohol consumption. Sixty-five stroke patients with a history of heavy drinking (HDS) and 83 stroke patients without such a history (NHDS) were recruited for analysis of the ADH1B and ALDH2 genotypes from the stroke registry in the Tri-Service General Hospital, Taipei, Taiwan, between January 2000 and December 2001. The allelotypes of ADH1B and ALDH2 were determined using the polymerase chain reaction-restriction fragment length polymorphism method. The HDS patients (3 per cent) showed a significantly lower ALDH2*2 allele frequency than NHDS patients (27 per cent) (p < 0.001). After controlling for age, patients with HDS were associated with a significantly higher occurrence of cigarette smoking (p < 0.01) and liver dysfunction (p < 0.01). Multiple logistic regression analyses revealed that the ALDH2*2 variant allele was an independent variable exhibiting strong protection (odds ratio 0.072; 95 per cent confidence interval 0.02-0.26) against HDS after adjustment for hypertension, diabetes mellitus, smoking status and liver dysfunction. By contrast, allelic variations in ADH1B exerted no significant effect on HDS. The present study indicated that, unlike ALDH2*2, ADH1B*2 appears not to be a significant negative risk factor for high alcohol consumption in male Han Chinese with stroke.

Heavy binge drinking may increase risk of stroke in nonalcoholic hypertensives carrying variant ALDH2*2 gene allele.

PURPOSE: Epidemiologic evidence demonstrates that heavy drinking increases the risk of stroke. However, whether recent heavy drinking affects the incidence of acute stroke in nonalcoholic individuals with the variant allele ALDH2*2 has not been reported. CASE REPORT: Two previously nonalcoholic healthy men suffered from acute ischemic stroke after a single episode of binge drinking. Both patients had one risk factor for stroke (a history of hypertension) and were heterozygous for ALDH2*2. CONCULUSION: The confluence of these factors with stroke has raised the possibility that heavy binge drinking increases the risk of acute stroke in hypertensives with the variant ALDH2*2 gene allele.

Preoperative APACHE II and GCS scores as predictors of outcomes in patients with malignant MCA infarction after decompressive hemicraniectomy.

OBJECTIVE: Decompressive hemicraniectomy is accepted as the most effective life-saving treatment for malignant middle cerebral artery (MCA) infarction. However, the outcome remains hard to predict. This study examined the efficacy of using the Glasgow Coma Scale (GCS) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores before emergency craniectomy for predicting clinical outcome in malignant MCA infarction. MATERIALS AND METHODS: Seventy-nine consecutive patients with malignant MCA infarction treated from January 2006 to October 2010 were retrospectively analyzed. The GCS and APACHE II scores within the first 24 h of neurological deterioration or before decompressive hemicraniectomy, were used to predict short-term functional outcome rated by the modified Rankin Scale (mRS). The receiver operating characteristic (ROC) curve was obtained to determine the accuracy and best cut-off value for each scoring system. RESULTS: At 6 months, there was dramatic life-saving effect of surgery, with a significant reduction in mortality rate (from 71% to 19%, P < 0.001). After the ROC analysis, cut-off values of pre-operative GCS > 8 (P = 0.003) and APACHE II <13 (P = 0.006) were sufficiently sensitive and specific to predict favorable outcome (mRS 0-3). CONCLUSIONS: Pre-operative GCS and APACHE II scores are useful tools in predicting outcomes for patients with malignant MCA infarction who underwent decompressive hemicraniectomy.

Arterial input function segmentation based on a contour geodesic model for tissue at risk identification in ischemic stroke.

PURPOSE: Perfusion parameters such as cerebral blood flow (CBF) and Tmax have been proven to be useful in the diagnosis and prognosis for ischemic stroke. Arterial input function (AIF) is required as an input to estimate perfusion parameters. This makes the AIF selection paradigm of clinical importance. METHODS: This study proposes a new technique to address the problem of AIF selection, based on a variational segmentation model that combines geometric constraint in a distance function. The modified model uses discrete total variation in the distance term and via minimizing energy locates the arterial regions. Matrix analysis is utilized to identify the AIF with maximum peak height within the segmented region. RESULTS: Group mean differences indicate that overall the AIF selected by the purposed method has better arterial features of higher peak position (16.7 and 26.1 a.u.) and fast attenuation (1.08 s and 0.9 s) as compared to the other state-of-the-art methods. Utilizing the selected AIF, mean CBF, and Tmax values were estimated higher than the traditional methods. Ischemic regions were precisely located through the perfusion maps. CONCLUSIONS: This AIF segmentation framework worked on perfusion images at levels superior to the current clinical state of the art. Consequently, the perfusion parameters derived from AIF selected by the purposed method were more accurate and reliable. The proposed method could potentially be considered as part of the calculation for perfusion imaging in general.

Optimal Scaling Approaches for Perfusion MRI with Distorted Arterial Input Function (AIF) in Patients with Ischemic Stroke.

BACKGROUND: Diagnosis and timely treatment of ischemic stroke depends on the fast and accurate quantification of perfusion parameters. Arterial input function (AIF) describes contrast agent concentration over time as it enters the brain through the brain feeding artery. AIF is the central quantity required to estimate perfusion parameters. Inaccurate and distorted AIF, due to partial volume effects (PVE), would lead to inaccurate quantification of perfusion parameters. METHODS: Fifteen patients suffering from stroke underwent perfusion MRI imaging at the Tri-Service General Hospital, Taipei. Various degrees of the PVE were induced on the AIF and subsequently corrected using rescaling methods. RESULTS: Rescaled AIFs match the exact reference AIF curve either at peak height or at tail. Inaccurate estimation of CBF values estimated from non-rescaled AIFs increase with increasing PVE. Rescaling of the AIF using all three approaches resulted in reduced deviation of CBF values from the reference CBF values. In most cases, CBF map generated by rescaled AIF approaches show increased CBF and Tmax values on the slices in the left and right hemispheres. CONCLUSION: Rescaling AIF by VOF approach seems to be a robust and adaptable approach for correction of the PVE-affected multivoxel AIF. Utilizing an AIF scaling approach leads to more reasonable absolute perfusion parameter values, represented by the increased mean CBF/Tmax values and CBF/Tmax images.

The optimal pulse pressures for healthy adults with different ages and sexes correlate with cardiovascular health metrics.

Background: Pulse pressure (PP) may play a role in the development of cardiovascular disease, and the optimal PP for different ages and sexes is unknown. In a prospective cohort, we studied subjects with favorable cardiovascular health (CVH), proposed the mean PP as the optimal PP values, and demonstrated its relationship with healthy lifestyles. Methods and results: Between 1996 and 2016, a total of 162,636 participants (aged 20 years or above; mean age 34.9 years; 26.4% male subjects; meeting criteria for favorable health) were recruited for a medical examination program. PP in male subjects was 45.6 ± 9.4 mmHg and increased after the age of 50 years. PP in female subjects was 41.8 ± 9.5 mmHg and increased after the age of 40 years, exceeding that of male subjects after the age of 50 years. Except for female subjects with a PP of 40-70 mmHg, PP increase correlates with both systolic blood pressure (BP) increase and diastolic BP decrease. Individuals with mean PP values are more likely to meet health metrics, including body mass index (BMI) <25 kg/m2 (chi-squared = 9.35, p<0.01 in male subjects; chi-squared = 208.79, p < 0.001 in female subjects) and BP <120/80 mmHg (chi-squared =1,300, p < 0.001 in male subjects; chi-squared =11,000, p < 0.001 in female subjects). We propose a health score (Hscore) based on the sum of five metrics (BP, BMI, being physically active, non-smoking, and healthy diet), which significantly correlates with the optimal PP. Conclusion: The mean PP (within ±1 standard deviation) could be proposed as the optimal PP in the adult population with favorable CVH. The relationship between health metrics and the optimal PP based on age and sex was further demonstrated to validate the Hscore.