Evaluation of Multiplex Rapid Antigen Tests for the Simultaneous Detection of SARS-CoV-2 and Influenza A/B Viruses

Single-target rapid antigen tests (RATs) are commonly used to detect highly transmissible respiratory viruses (RVs), such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses. The simultaneous detection of RVs presenting overlapping symptoms is vital in making appropriate decisions about treatment, isolation, and resource utilization; however, few studies have evaluated multiplex RATs for SARS-CoV-2 and other RVs. We assessed the diagnostic performance of multiplex RATs targeting both the SARS-CoV-2 and influenza A/B viruses with the GenBody Influenza/COVID-19 Ag Triple, InstaView COVID-19/Flu Ag Combo (InstaView), STANDARDTM Q COVID-19 Ag Test, and STANDARDTM Q Influenza A/B Test kits using 974 nasopharyngeal swab samples. The cycle threshold values obtained from the real-time reverse transcription polymerase chain reaction results showed higher sensitivity (72.7-100%) when the values were below, rather than above, the cut-off values. The InstaView kit exhibited significantly higher positivity rates (80.21% for SARS-CoV-2, 61.75% for influenza A, and 46.15% for influenza B) and cut-off values (25.57 for SARS-CoV-2, 21.19 for influenza A, and 22.35 for influenza B) than the other two kits, and was able to detect SARS-CoV-2 Omicron subvariants. Therefore, the InstaView kit is the best choice for routine screening for both SARS-CoV-2 and influenza A/B in local communities.

Status of Pre-analytical Quality Management of Laboratory Tests at Primary Clinics in Korea

Background

The quality of laboratory test results is crucial for accurate clinical diagnosis and treatment. Pre-analytical errors account for approximately 60%-70% of all laboratory test errors. Laboratory test results may be largely impacted by pre-analytical phase management. However, primary care clinics currently do not have pre-analytical quality management audit systems. We aimed to understand the current status of pre-analytical quality management in laboratory medicine in Korean primary care clinics.

Methods

Questionnaires were designed to focus on essential components of the pre-analytical process of primary care clinics. An online survey platform was used to administer the survey to internal medicine or family medicine physicians in primary care clinics.

Results

A total of 141 physicians provided a complete response to the questionnaire. In 65.2% of the clinics, patient information was hand-labeled rather than barcoded on the specimen bottles; 14.2% of clinics displayed only one piece of patient information (name or identification number), and 19.9% of clinics displayed two pieces of information. Centrifuges were not available in 29.1% of the clinics. Institutions carrying out the National Health Screening Program (NHSP) used more barcode system and had more centrifuges than institutions that did not carrying out the NHSP.

Conclusions

Pre-analytical quality management is inadequate in many primary clinics. We suggest implementation of a mandatory management system, allowing for a pre-analytical quality management to be carried out in primary care clinics.

Evaluation of Rapid Multiplex Reverse Transcription-Quantitative Polymerase Chain Reaction Assays for SARS-CoV-2 Detection in Individual and Pooled Samples

Although coronavirus disease 2019 (COVID-19) is no longer a Public Health Emergency of International Concern (PHEIC), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has had a vast impact to date. Hence, continuous management is required, given the uncertainty caused by the potential evolution of SARS-CoV-2. Reverse transcription-quantitative PCR (RT-qPCR) diagnosis has been fundamental in overcoming this issue. In this study, the performances of two rapid RT-qPCR assays (Real-Q Direct SARS-CoV-2 Detection Kit and Allplex™ SARS-CoV-2 fast PCR Assay) with short PCR times were comparatively evaluated using a STANDARD M nCoV Real-Time Detection Kit (STANDARD M, conventional RT-qPCR assay). All kits showed a limit of detection values (102-103 copies/reaction). The evaluation showed that the two rapid assay tests had ≥97.89% sensitivity and ≥99.51% specificity (κ = 0.98) for individual samples and ≥97.32% sensitivity and ≥97.67% specificity for pooled samples compared to STANDARD M. These results indicate that the two rapid RT-qPCR kits, which showed significant time reduction in performance, are as effective as a conventional RT-qPCR assay. They are likely to increase not only the number of tests that can be performed but also the efficiency of sustainable management of COVID-19 in the long term.

Changing Epidemiology of Pathogenic Bacteria Over the Past 20 Years in Korea

BACKGROUND

The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea.

METHODS

From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea.

RESULTS

The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively. Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016.

CONCLUSION

The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Evaluation of Four Rapid Antigen Tests for the Detection of SARS-CoV-2 Infection with Nasopharyngeal Swabs

Owing to the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the capacity of testing systems based on the gold standard real-time reverse transcription–polymerase chain reaction (rRT-PCR) is limited. Rapid antigen tests (RATs) can substantially contribute to the prevention of community transmission, but their further assessment is required. Here, using 1503 nasopharyngeal swabs, we compared the diagnostic performance of four RAT kits (Abbott Panbio™ COVID-19 Ag Rapid Test, SD Biosensor Standard™ Q COVID-19 Ag Test, Humasis COVID-19 Ag Test, and SG Medical Acrosis COVID-19 Ag Test) to the cycle threshold (Ct) values obtained from rRT-PCR. The precision values, area under the curve values, SARS-CoV-2 variant detection ability, and non-SARS-CoV-2 specificity of all four kits were similar. An assay using the Acrosis kit had a significantly better positive detection rate with a higher recall value and cut-off value than that using the other three RAT kits. During the current COVID-19 pandemic, the Acrosis kit is an effective tool to prevent the spread of SARS-CoV-2 in communities.

Changes in the characteristics of community-onset fluoroquinolone-resistant Escherichia coli isolates causing community-acquired acute pyelonephritis in South Korea

PURPOSE

This study aimed to examine the changes in the characteristics of community-onset fluoroquinolone-resistant (FQ-R) Escherichia coli isolates causing community-acquired acute pyelonephritis (APN) in South Korea.

METHODS

Blood or urine samples were prospectively collected from patients aged ≥15 years with community-acquired APN who were admitted to one of the eight Korean hospitals included in this study between September 2017 and August 2018. Phylogenetic typing, multilocus sequence typing, and molecular characterization of β-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from a previous study with the same design conducted in 2010-2011.

RESULTS

A total of 300 and 346 isolates were identified in 2010-2011 and 2017-2018, respectively. Among them, 76 (22.0%) and 77 (25.7%) FQ-R isolates were identified in 2010-2011 and 2017-2018, respectively. A significantly higher antimicrobial resistance against third-to fourth-generation cephalosporins, including cefotaxime (23.9% vs. 77.9%, P < 0.001), were observed among FQ-R isolates in 2017-2018 than among those in 2010-2011. A higher proportion of ST131 isolates (27.6% vs. 66.2%, P < 0.001), as well as isolates that had extended-spectrum β-lactamase (ESBL)/plasmid-mediated AmpC β-lactamase (PABL) (23.7% vs. 79.2%, P < 0.001), was observed in 2017-2018 than in 2010-2011. Further, more PMQR determinants (11.8% vs. 40.8%, P < 0.001) were observed in 2017-2018 than in 2010-2011.

CONCLUSIONS

Among uropathogenic FQ-R E. coli isolates in South Korea, the prevalence of ST131 and the proportion of isolates containing ESBL and/or PMQR determinants have increased.

Relationship between the appropriateness of antibiotic treatment and clinical outcomes/medical costs of patients with community-acquired acute pyelonephritis: a multicenter prospective cohort study

BACKGROUND

Inappropriate use of antibiotics not only increases antibiotic resistance as collateral damage but also increases clinical failure rates and medical costs. The purpose of this study was to determine the relationship between the appropriateness of antibiotic prescription and outcomes of community-acquired acute pyelonephritis (CA-APN).

METHODS

A multicenter prospective cohort study was conducted at eight hospitals in Korea between September 2017 and August 2018. All hospitalized patients aged ≥ 19 years who were diagnosed with CA-APN on admission were recruited. The appropriateness of empirical and definitive antibiotics, as well as the appropriateness of antibiotic treatment duration and route of administration, was evaluated in accordance with the guideline and expert opinions. Clinical outcomes and medical costs were compared between patients who were administered antibiotics 'appropriately' and 'inappropriately.'

RESULTS

A total of 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of them, 10 (2.5%) and 18 (5.7%) were administered 'inappropriately' empirical and definitive antibiotics, respectively. Of the 119 patients whose use of both empirical and definitive antibiotics was classified as 'optimal,' 57 (47.9%) received antibiotics over a longer duration than that recommended; 67 (56.3%) did not change to oral antibiotics on day 7 of hospitalization, even after stabilization of the clinical symptoms. Patients who were administered empirical antibiotics 'appropriately' had shorter hospitalization days (8 vs. 10 days, P = 0.001) and lower medical costs (2381.9 vs. 3235.9 USD, P = 0.002) than those who were administered them 'inappropriately.' Similar findings were observed for patients administered both empirical and definitive antibiotics 'appropriately' and those administered either empirical or definitive antibiotics 'inappropriately'.

CONCLUSIONS

Appropriate use of antibiotics leads to better outcomes, including reduced hospitalization duration and medical costs.

Incidence, Clinical Characteristics, and Genotype Distribution of Rotavirus in a Neonatal Intensive Care Unit 5 Years After Introducing Rotavirus Vaccine

BACKGROUND

Rotavirus (RV) is a common cause of viral gastroenteritis in children worldwide. We aimed to investigate the incidence, symptoms, and genotype of RV infection in a neonatal intensive care unit (NICU) in South Korea 5 years after the introduction of RV vaccination to evaluate its effect on newborn infants.

METHODS

A total of 431 fecal specimens were collected from patients admitted to NICU between April 20, 2012 and September 10, 2013. Enzyme-linked immunoassays were used to detect RV antigen. Nested multiplex polymerase chain reaction was used for genotyping.

RESULTS

The overall incidence of RV infection was 43.9% and was significantly higher in preterm infants, infants born in the study hospital, low birth weight infants, and cesarean births (P < 0.05). Symptoms of diarrhea, poor feeding, abdominal distension, and apnea were significantly higher in infants with RV infection than those without infection. RV infection gradually increased depending on infant care at home, postpartum clinic, or hospital (26.0, 45.1, and 60.2%, respectively; P = 0.000). The dominant RV genotype in the NICU was G4P[6] at 95.4%.

CONCLUSION

Current RV vaccines did not affect the incidence of RV infection in newborn and preterm infants in the NICU. Most RV-positive patients in the NICU had symptoms, and the incidence of RV infection was relatively higher in hospitals and postpartum clinics with group life than home. The dominant RV genotype was G4P[6] across study groups.

Comparison of the clinical characteristics of community-acquired acute pyelonephritis between male and female patients

BACKGROUND

Community-acquired acute pyelonephritis (CA-APN) is relatively rare in men. This study aimed to compare the clinical characteristics of CA-APN between male and female patients.

METHODS

We prospectively collected the clinical and microbiological data of hospitalized CA-APN patients aged ≥19 years in South Korea from March 2010 to February 2011 in 11 hospitals and from September 2017 to August 2018 in 8 hospitals. Only the first episodes of APN of each patient during the study period were included.

RESULTS

From 2010 to 2011, 573 patients from 11 hospitals were recruited, and from 2017 to 2018, 340 patients were recruited from 8 hospitals. Among them, 5.9% (54/913) were male. Male patients were older (66.0 ± 15.2 vs. 55.3 ± 19.0 years, P < 0.001), had a higher Charlson comorbidity index (1.3 ± 1.5 vs. 0.7 ± 1.2, P = 0.027), and had a higher proportion of structural problems in the urinary tract (40.7% vs. 6.1%, P < 0.001) than female patients. Moreover, the total duration of antibiotic treatment was longer (21.8 ± 17.8 d vs. 17.3 ± 9.4 d, P = 0.001) and the proportion of carbapenem usage was higher (24.1% vs. 9.5%, P = 0.001) in men than in women. Male patients were hospitalized for longer durations than female patients (median, 10 d vs. 7 d, P < 0.001).

CONCLUSIONS

Male CA-APN patients were older and had more comorbidities than female CA-APN patients. In addition, male patients received antibiotic treatment for a longer duration than female patients.

1667. Change in characteristics of community-onset ciprofloxacin-resistant E. coli isolates causing community-acquired acute pyelonephritis in South Korea

Background

The aim of this study was to examine the change in characteristics of community-onset ciprofloxacin-resistant (CIP-R) E. coli isolates causing community-acquired acute pyelonephritis (CA-APN) in South Korea between 2010-2011 and 2017-2018.

Methods

E. coli samples isolated from the blood or urine were collected from patients with CA-APN aged 19 years and more who were admitted to 8 Korean hospitals from September 2017 to August 2018, prospectively. One isolate was collected from each patient. Phylogenetic typing, multilocus sequence typing (MLST), and molecular characterization of β-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from the previous study with same design in 2010-2011.

Results

A total of 346 and 300 isolates were collected during 2017-2018 and 2010-2011, respectively. Among them, 76 (22.0%) and 77 (25.7%) were CIP-R isolates. Significantly higher antimicrobial resistance against ampicillin (75.7% vs. 100%, P < 0.001) and cefotaxime (23.9% vs. 77.9%, P < 0.001) were observed for isolates in 2017-2018 compared to those in 2010-2011. The proportion of phylogenic group B2 had increased significantly (44.7% vs. 79.2%, P < 0.001). As for MLST, the proportion of ST131 (27.6% vs. 66.2%, P < 0.001) had increased while that of ST393 (18.4% vs. 3.9%, P =0.004) had decreased significantly. Higher proportion of CIP-R E. coli isolates in 2017-2018 had extended-spectrum β-lactamase (ESBL)/plasmid-mediated AmpC β-lactamase (PABL) (23.7% vs. 79.2%, P < 0.001) and PMQR determinant (11.8% vs. 40.8%, P < 0.001) compared to those in 2010-2011.

Phlogenetic tree

Analyzed by SplitsTree

Conclusion

Among uropathogenic CIP-R E. coli isolates in South Korea, ST131 predominance had become more prominent and the proportion of containing ESBL/PABL and/or PMQR determinants had increased.

Disclosures

All Authors: No reported disclosures

Sex-specific association of urate and levodopa-induced dyskinesia in Parkinson's disease

BACKGROUND AND PURPOSE

As a major antioxidant, uric acid (UA) is known to be associated with the clinical progression of Parkinson's disease (PD). This study investigated whether baseline UA levels are associated with the risk for levodopa-induced dyskinesia (LID) in PD in a sex-dependent manner.

METHODS

In all, 152 patients with de novo PD (78 males and 74 females) who were followed up for >2 years were enrolled. The effect of baseline serum UA levels on LID-free survival was assessed by Cox regression, separately for sex, whilst being adjusted for potential confounding factors. The optimal UA level cut-off value to determine the high-risk group for LID was set using Contal and O'Quigley's method.

RESULTS

Levodopa-induced dyskinesia developed in 23 (29.5%) male patients and 30 (40.5%) female patients. Cox regression showed a significant interaction between UA level and sex. Higher UA levels were associated with a higher risk for LID in male PD patients (hazard ratio 1.380; 95% confidence interval 1.038-1.835; P = 0.027), although this relationship was not observed in female PD patients. The optimal UA level cut-off for LID in male PD was 7.2 mg/dl, and the high UA group had a 5.7-fold higher risk of developing LID than the low UA group.

CONCLUSIONS

Contrary to a presumptive beneficial role of UA, the present study demonstrated that higher UA levels are associated with increased risk of LID occurrence in male patients with PD, suggesting a sex-dependent role of UA in LID.

Cognitive anosognosia is associated with frontal dysfunction and lower depression in Parkinson's disease

BACKGROUND AND PURPOSE

Anosognosia refers to a deficit of self-awareness or impaired insight for cognitive and behavioral problems. Cognitive anosognosia was explored in de novo patients with Parkinson's disease (PD) and its relationship to cognitive function and neuropsychiatric symptoms was investigated.

METHODS

The cross-sectional study enrolled 340 drug-naïve patients with PD. According to the presence of mild cognitive impairment (MCI) and subjective cognitive complaint, patients were classified as patients with cognitive anosognosia (PD-CA, n = 74), with normal cognitive recognition (PD-NR, n = 184) or with cognitive underestimation (PD-CU, n = 82). After controlling for covariates, cognitive performance and neuropsychiatric symptoms were compared between the PD groups.

RESULTS

Cognitive anosognosia was found in 21.8% of patients with de novo PD. The PD-CA group showed poorer performance in all cognitive domains except for attention. Amongst PD patients with MCI, those with cognitive anosognosia showed lower composite z-scores in the Stroop color reading test than those without. The Beck Depression Inventory score in the PD-NR group was lower than that in the PD-CU group and higher than that in the PD-CA group. The Cognitive Complaints Interview score mediated the association between cognitive anosognosia and Beck Depression Inventory score.

CONCLUSIONS

Cognitive anosognosia in PD was associated with greater frontal dysfunction and lower depression. Since cognitive anosognosia has a harmful impact on PD patients and their caregivers due to overestimation of their abilities in everyday life, early identification of cognitive anosognosia in PD is important in management and prognosis.

1451. Change in Clinical Characteristics of Community-Acquired Acute Pyelonephritis in South Korea: Comparison Between 2010–2011 and 2017–2018

Background

The aim of this study was to examine the change in clinical characteristics of community-acquired acute pyelonephritis (CA-APN) in South Korea between 2010–2011 and 2017–2018.

Methods

We recruited all CA-APN patients with age ≥19 years who visited 4 hospitals in South Korea from September 2017 to August 2018, prospectively. The inclusion criteria were: (i) presence of fever (body temperature ≥37.8°C), (ii) pyuria [≥5–9 white blood cells per high power field (WBC/HPF)], and (iii) clinical symptoms or signs relevant to APN. Patients diagnosed with APN more than 48 hours after admission, those transferred from other hospitals during treatment of APN, those with other reasons for fever and pyuria, and those with insufficient data were excluded. Each patient was included for the first episode during the study period. The collected data were compared with those from the previous study with the same design in 2010–2012, in which the same hospitals were participated.

Results

A total of 349 and 472 patients were recruited during 2017–2018 and 2010–2011, respectively. E. coli was the most common causative pathogen for CA-APN in both periods (87.5% vs. 86.6%, P = 0.727). Significantly higher antimicrobial resistance against fluoroquinolone (33.5% vs. 21.0%, P = 0.001), cefotaxime (34.8% vs. 7.6%, P P = 0.040) were observed for E. coli isolates in 2017–2018 compared with those in 2010–2011. The patients in 2017–2018 were older (60.71±17.29 vs. 55.77±18.60, P <0.001) and had higher Charlson’s comorbidity index (1.04±1.39 vs. 0.68±1.17, P<0.001) than those in 2010–2011. Total duration of antibiotic treatment increased from 15.40 ± 6.35 days in 2010–2011 to 21.74 ± 11.72 days in 2017–2018, P <0.001); the proportion of patients using carbapenem increased from 6.1% in 2010–2011 to 26.6% in 2010–2011 (P < 0.001). The median days of admission was higher for patients in 2017–2018 than those in 2010–2011 (10 vs. 8, P < 0.001).

Conclusion

Patients with CA-APN in South Korea were aging. Antimicrobial resistance of E. coli to almost all antibiotic classes, especially third-generation cephalosporin, increased significantly and total duration of antibiotic treatment and proportion of carbapenem usage increased, consequently.

Disclosures

All authors: No reported disclosures.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Clinical relevance of amnestic versus non-amnestic mild cognitive impairment subtyping in Parkinson's disease

BACKGROUND AND PURPOSE

To clarify whether subtyping of amnestic and non-amnestic mild cognitive impairment (MCI) is clinically relevant in Parkinson's disease (PD) by analyzing patterns of neuroimaging and longitudinal cognitive changes.

METHODS

We performed comparative analyses of cortical thickness, hippocampal volume, white matter integrity and resting-state functional connectivity between the patients with de-novo PD with amnestic MCI (PD-aMCI) (n = 50) and non-amnestic MCI (PD-naMCI) (n = 50) subtypes. Additionally, we assessed the longitudinal rate of cognitive decline in each cognitive domain over time and the rate of dementia conversion in patients with de-novo PD-aMCI (n = 125) and PD-naMCI (n = 61).

RESULTS

The demographic data showed that scores in memory domains were lower in the PD-aMCI group compared with the PD-naMCI group. There were no significant differences in cortical thickness, hippocampal volume and white matter integrity between the two groups, although the PD-aMCI group exhibited more cortical thinning and hippocampal atrophy relative to the control group. The PD-aMCI group exhibited increased functional connectivity in the left posterior parietal region with the salience network relative to the PD-naMCI group. The longitudinal cognitive assessment demonstrated that patients with PD-aMCI exhibited a more rapid cognitive decline in frontal/executive function than those with PD-naMCI (P = 0.022). In addition, the PD-aMCI group had a higher risk of dementia conversion than the PD-naMCI group.

CONCLUSIONS

This study suggests that the designation of PD-MCI subtypes based on memory function would highlight the heterogeneity of functional correlates as well as the longitudinal cognitive prognosis.

Does serum uric acid act as a modulator of cerebrospinal fluid Alzheimer's disease biomarker related cognitive decline?

BACKGROUND AND PURPOSE

The association of serum uric acid, cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and longitudinal cognitive decline was evaluated using the AD Neuroimaging Initiative database.

METHODS

In 271 healthy subjects, 596 mild cognitive impairment patients and 197 AD patients, serum uric acid and CSF AD biomarkers were measured at baseline, and Mini-Mental State Examination and AD Assessment Scale - Cognitive Subscale (ADAS-cog) were assessed serially (mean duration, 2.9 years). The effect of uric acid on longitudinal cognitive decline was evaluated using linear mixed effect models for Mini-Mental State Examination and ADAS-cog scores in female and male subjects separately, with possible confounders controlled (model 1). To determine the effects of uric acid independent of CSF biomarker (Aβ1-42 or tau) and to test whether the detrimental effects of CSF biomarker differ according to uric acid, CSF biomarker and its interaction with uric acid were further included in model 1 (model 2).

RESULTS

Higher levels of uric acid were associated with slower cognitive decline, particularly in the mild cognitive impairment and dementia subgroups, and more prominently in female subjects. Model 2 with CSF Aβ1-42 showed that higher levels of uric acid were associated with a slower cognitive decline and alleviated the detrimental effect of Aβ1-42 on cognitive decline. Model 2 with CSF tau showed that higher levels of uric acid alleviated the detrimental effect of tau on cognitive decline in female subjects but not in male subjects.

CONCLUSION

Higher levels of uric acid had protective effects on longitudinal cognitive decline independent of and interactively with CSF AD biomarkers.

Evaluation of three glucometers for whole blood glucose measurements at the point of care in preterm or low-birth-weight infants

Purpose

We evaluated three blood glucose self-monitoring for measuring whole blood glucose levels in preterm and low-birth-weight infants.

Methods

Between December 1, 2012 and March 31, 2013, 230 blood samples were collected from 50 newborns, who weighed, ≤2,300 g or were ≤36 weeks old, in the the neonatal intensive care unit of Eulji University Hospital. Three blood glucose self-monitoring (A: Precision Pcx, Abbott; B: One-Touch Verio, Johnson & Johnson; C: LifeScan SureStep Flexx, Johnson & Johnson) were used for the blood glucose measurements. The results were compared to those obtained using laboratory equipment (D: Advia chemical analyzer, Siemens Healthcare Diagnostics Inc.).

Results

The correlation coefficients between laboratory equipment and the three blood glucose self-monitoring (A, B, and C) were found to be 0.888, 0.884, and 0.900, respectively. For glucose levels≤60 mg/dL, the correlation coefficients were 0.674, 0.687, and 0.679, respectively. For glucose levels>60 mg/dL, the correlation coefficients were 0.822, 0.819, and 0.839, respectively. All correlation coefficients were statistically significant. And the values from the blood glucose self-monitoring were not significantly different from the value of the laboratory equipment , after correcting for each device's average value (P>0.05). When using laboratory equipment (blood glucose ≤60 mg/dL), each device had a sensitivity of 0.458, 0.604, and 0.688 and a specificity of 0.995, 0.989, and 0.989, respectively.

Conclusion

Significant difference is not found between three blood glucose self-monitoring and laboratory equipment. But correlation between the measured values from blood glucose self-monitoring and laboratory equipment is lower in preterm or low-birth-weight infants than adults.

MAGNETOCALORIC RESPONSE OF NON-STOICHIOMETRIC Ni2MnGa ALLOYS AND THE INFLUENCE OF CRYSTALLOGRAPHIC TEXTURE

Currently, there is significant interest in magnetocaloric materials for solid state refrigeration. In this work, polycrystalline Heusler alloys belonging to the Ni2+xMn1-xGa family, with x between 0.08 and 0.24, were evaluated for the purpose of finding composition(s) with an enhanced magnetocaloric effect (MCE) close to room temperature. Differential scanning calorimetry (DSC) was successfully used to screen alloy composition for simultaneous magnetic and structural phase transformations; this coupling needed for a giant MCE. The alloy with x = 0.16 showed an excellent match of transformation temperatures and exhibited the highest magnetic entropy change, ΔSM, in the as-annealed state. Furthermore, the MCE increased by up to 84 % with a 2 Tesla (T) field change when the samples were thermally cycled through the martensite to austenite transformation temperature while held under a constant mechanical load. The highest ΔSM measured for our x = 0.16 alloy for a 2 T magnetic field change was -18 J/kg-K. Texture measurements suggest that preferential orientation of martensite variants contributed to the enhanced MCE in the stress-assisted thermally cycled state.

Multicenter evaluation of Seegene Anyplex TB PCR for the detection of Mycobacterium tuberculosis in respiratory specimens

Culture is the gold standard for diagnosis of tuberculosis, but it takes 6 to 8 weeks to confirm the result. This issue is complemented by the detection method using polymerase chain reaction, which is now widely used in a routine microbiology laboratory. In this study, we evaluated the performance of the Seegene Anyplex TB PCR to assess its diagnostic sensitivity and specificity, and compared its results with the Roche Cobas TaqMan MTB PCR, one of the most widely used assays in the world. Five university hospitals located in the Chungcheong area in South Korea participated in the study. A total of 1,167 respiratory specimens ordered for acid-fast bacilli staining and culture were collected for four months, analyzed via the Seegene Anyplex TB PCR, and its results were compared with the Roche Cobas TaqMan MTB PCR. For detection of Mycobacterium tuberculosis, the diagnostic sensitivity and specificity of the Anyplex TB PCR were 87.5% and 98.2% respectively, whereas those of the Cobas TaqMan were 92.0% and 98.0% respectively (p value > 0.05). For smear-positive specimens, the sensitivity of the Anyplex TB PCR was 95.2%, which was exactly the same as that of the Cobas TaqMan. For smear-negative specimens, the sensitivity of the Anyplex TB PCR was 69.2%, whereas that of the Cobas TaqMan TB PCR was 84.6%. For detection of MTB, the Seegene Anyplex TB PCR showed excellent diagnostic performance, and high sensitivity and specificity, which were comparable to the Roche Cobas TaqMan MTB PCR. In conclusion, the Anyplex TB PCR can be a useful diagnostic tool for the early detection of tuberculosis in clinical laboratories.

Performance evaluation of ExiStation HBV diagnostic system for hepatitis B virus DNA quantitation

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The new real-time quantitative PCR system for hepatitis B virus was evaluated.

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This system showed satisfactory analytical sensitivity, excellent reproducibility, no cross-reactivity, no interference and high correlation with other real-time PCR assays.

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The assay is a useful tool for the detection and monitoring of hepatitis B virus infection.

The performance of a recently developed real-time PCR system, the ExiStation HBV diagnostic system, for quantitation of hepatitis B virus (HBV) in human blood was evaluated. The detection limit, reproducibility, cross-reactivity, and interference were evaluated as measures of analytical performance. For the comparison study, 100 HBV-positive blood samples and 100 HBV-negative samples from Korean Blood Bank Serum were used, and the results of the ExiStation HBV system showed good correlation with those obtained using the Cobas TaqMan (r² = 0.9931) and Abbott real-time PCR systems (r² = 0.9894). The lower limit of detection was measured as 9.55 IU/mL using WHO standards and the dynamic range was linear from 6.68 to 6.68 × 10⁹ IU/mL using cloned plasmids. The within-run coefficient of variation (CV) was 9.4%, 2.1%, and 1.1%, and the total CV was 11.8%, 3.6%, and 1.7% at a concentration of 1.92 log₁₀ IU/mL, 3.88 log₁₀ IU/mL, and 6.84 log₁₀ IU/mL, respectively. No cross-reactivity or interference was detected. The ExiStation HBV diagnostic system showed satisfactory analytical sensitivity, excellent reproducibility, no cross-reactivity, no interference, and high agreement with the Cobas TaqMan and Abbott real-time PCR systems, and is therefore a useful tool for the detection and monitoring of HBV infection.

Neuroanatomic basis of amnestic MCI differs in patients with and without Parkinson disease

OBJECTIVE

To explore the neuroanatomic basis of amnestic mild cognitive impairment (aMCI) in patients with Parkinson disease (PD; aMCI-PD(+)) and without PD (aMCI-PD(-)).

METHODS

A total of 119 patients with aMCI (aMCI-PD(-), n = 78, and aMCI-PD(+), n = 41) underwent T1-weighted MRI, and the image data were analyzed using voxel-based morphometry.

RESULTS

No significant differences in demographic characteristics or general cognition were found between patients with aMCI-PD(-) and aMCI-PD(+). Comparisons of neuropsychological tests between groups revealed that patients with aMCI-PD(-) had lower scores in delayed verbal and visual recognition memory, whereas visuospatial dysfunction was more severe in patients with aMCI-PD(+). Gray matter (GM) density in the right temporal and posterior cingular cortices was significantly lower in the aMCI-PD(-) group compared with controls. In contrast, GM density in the aMCI-PD(+) group was significantly lower in the precuneus and left prefrontal and primary motor areas relative to controls. A direct comparison between groups showed that decreased GM density in aMCI-PD(-) relative to aMCI-PD(+) was localized in the right temporal and anterior prefrontal areas, whereas decreased GM density in aMCI-PD(+) relative to aMCI-PD(-) was involved in the bilateral precuneus, left primary motor, and right parietal areas. Memory decline was correlated with temporal area atrophy in aMCI-PD(-) and with posterior cingulate cortex atrophy in aMCI-PD(+).

CONCLUSIONS

Our data suggest that different neuroanatomic systems underlie memory dysfunction in patients with aMCI-PD(-) and aMCI-PD(+).

Performance evaluation of the Abbott RealTime HCV Genotype II for hepatitis C virus genotyping

BACKGROUND

The Abbott RealTime hepatitis C virus (HCV) Genotype II (Abbott Molecular Inc.) for HCV genotyping, which uses real-time PCR technology, has recently been developed.

METHODS

Accuracy and sensitivity of detection were assessed using the HCV RNA PHW202 performance panel (SeraCare Life Sciences). Consistency with restriction fragment mass polymorphism (RFMP) data, cross-reactivity with other viruses, and the ability to detect minor strains in mixtures of genotypes 1 and 2 were evaluated using clinical samples.

RESULTS

All performance panel viruses were correctly genotyped at levels of >500 IU/mL. Results were 100% concordant with RFMP genotypic data (66/66). However, 5% (3/66) of the samples examined displayed probable genotypic cross reactivity. No cross reactivity with other viruses was evident. Minor strains in the mixtures were not effectively distinguished, even at quantities higher than the detection limit.

CONCLUSIONS

The Abbott RealTime HCV Genotype II assay was very accurate and yielded results consistent with RFMP data. Although the assay has the advantages of automation and short turnaround time, we suggest that further improvements are necessary before it is used routinely in clinical practice. Efforts are needed to decrease cross reactivity among genotypes and to improve the ability to detect minor genotypes in mixed infections.

[Meta-analysis for the pooled sensitivity and specificity of anti-human immunodeficiency virus Ab rapid tests]

BACKGROUND

Many immunochromatography (ICA) kits for anti-human immunodeficiency virus type (HIV) antibody (Ab) have been introduced to improve the accessibility of HIV Ab tests. However, qualified evaluation reports for HIV rapid tests are not enough to validate their performances. Meta-analysis for the performances of the HIV Ab rapid tests was performed in this study.

METHODS

PubMed database was searched with combination of search terms, 'human immunodeficiency virus', 'HIV Ab', 'rapid test', 'immunochromatography', 'performance', 'sensitivity', and 'specificity'. Criteria of inclusion were performance studies for HIV ICA kits with serum or EDTA whole blood. Methodological qualities were evaluated with standards for reporting of diagnostic accuracy studies (STARD) checklists by two investigators. Homogeneity among selected studies was evaluated and then pooled sensitivity and specificity were calculated. Positive and negative predictive values were simulated with presumed HIV prevalence in Korea.

RESULTS

Twenty-three studies were selected from 12 high-qualified papers with STARD checklists. The performance of 23 studies were found to be heterogeneous (P<0.1) and random effect model was used. Pooled sensitivity was 99.71% (95% CI: 99.45-99.97%) and pooled specificity was 99.27% (95% CI: 98.83-99.70%). With HIV prevalence of 0.03%, positive and negative predictive values were presumed to be 3.936% and 99.999%, respectively.

CONCLUSIONS

This meta-analysis for HIV ICA rapid tests showed good performance. In consideration of low positive predictive values of HIV rapid tests, confirmation by enzyme immunoassay or Western blot is still needed. This study would be helpful in evaluating and establishing proper performance guideline for those kits not fully evaluated.

[Experience on identification of cross-reactive group specificity performed by anti-human globulin panel reactive antibody tests]

BACKGROUND

Panel reactive antibody (PRA) is to screen and identify HLA antibody. Majority of antibody specificities in high-PRA are directed against cross reactive group (CREG). Thus, this study was to know the advantage of identifying CREG specificity and whether antibody specificities are changed according to CREG classification.

METHODS

HLA class I antibodies were identified from 159 sera from 108 patients in Asan Medical Center, who had shown more than 5% PRA by anti-human globulin (AHG)-complement-dependent cytotoxicity (CDC). Tail analysis-based computer program was developed to identify specificities, applying both Rodey (R-ABC) and Takemoto (T-ABC) classification. The results were also compared with those obtained when without CREG application (ABC).

RESULTS

Among 151 cases in which HLA specificities was identified, the frequency of CREG specificity was 22.5% in R-ABC and 27.2% in T-ABC. Eleven cases showed CREG specificities only in one classification. However, the individual antigen specificities in one hand were all included in the CREG identified in the other hand. CREG specificities in samples with PRA >50% (60%) were more frequently identified than those in samples with PRA < or =50% (9%) (in R-ABC, P<0.0001). Without applying CREG to interpretation, specificity was not identified in 9 cases.

CONCLUSIONS

Application of CREG enhanced the rate of antibody identification. Antibody specificities of those cases where CREG specificities were different between Rodey and Takemoto classifications were almost the same when compared at the individual antigen level. Therefore, it was thought that it makes no difference to use any one of these two classifications in interpreting PRA.

Human leukocyte antigen alleles and haplotypes associated with chronicity of hepatitis B virus infection in Koreans

CONTEXT

Chronic hepatitis B infection is the leading cause of cirrhosis and hepatocellular carcinoma. Human leukocyte antigen may be involved in the chronicity of hepatitis B virus (HBV) infection.

OBJECTIVE

To analyze the association between HBV chronicity and human leukocyte antigen alleles and haplotypes of 636 organ donors and recipients.

DESIGN

Subjects were categorized into 2 groups according to their clinical and serologic profiles, specifically, an HBV natural convalescent group and an HBV chronic carrier (CC) group.

RESULTS

Hepatitis B chronicity was positively associated with A33 (P = .004, odds ratio [OR] = 1.59) and DR7 (P < .001, OR = 2.58), and negatively associated with HLA-DR13 (P < .001, OR = 0.40). Coexpression of A33 and DR7 was significantly higher in the CC group (OR = 3.63), compared with that of either allele alone (OR = 1.76 in A33; OR = 2.53 in DR7). The statistically significant haplotypes were B44-DR7 (P < .001, OR = 5.44), A33-DR7 (P < .001, OR = 4.47), and A33-B44-DR7 (P < .001, OR = 7.31) in the CC group.

CONCLUSIONS

Our results indicate that alleles of A33, DR7, and haplotypes containing DR7 are associated with HBV chronicity among Koreans. Moreover, the 2 antigens had an additive effect on chronicity. These findings support the theory that human leukocyte antigen class I-restricted cytotoxic T cells and human leukocyte antigen class II-restricted helper T cells play an important role in HBV chronicity.

Corticospinal disinhibition in paroxysmal kinesigenic dyskinesia

OBJECTIVE

To investigate the underlying mechanism responsible for paroxysmal kinesigenic dyskinesia (PKD).

METHODS

We performed a transcranial magnetic stimulation (TMS) study in 12 drug-naïve patients with PKD and 10 healthy volunteers. TMS parameters included resting motor threshold, recruitment curve of motor evoked potential amplitudes, short intracortical inhibition and facilitation, long intracortical inhibition (LICI), and silent period. We also measured compound muscle action potential.

RESULTS

LICI, representing GABA-mediated inhibition, was significantly reduced in the patients (P = 0.033), while results for all other TMS parameters tested were comparable between the two groups.

CONCLUSIONS AND SIGNIFICANCE

These results suggest that a specific type of corticospinal inhibitory mechanism is impaired in patients with PKD.

Flumazenil does not affect intracortical motor excitability in humans: a transcranial magnetic stimulation study

OBJECTIVE

The motor cortex may be subject to tonic inhibitory drive. One inhibitory mechanism is supported by activity at benzodiazepine (BZP) receptors. In this study we investigate whether or not the BZP antagonist, flumazenil, increases cortical motor excitability in humans.

METHODS

Eight healthy subjects received a 1 mg intravenous (i.v.) loading dose of flumazenil followed by a 0.5 mg i.v. infusion over the next 30 min. Before, during, and 1 h after flumazenil infusion, we measured cortical motor excitability using transcranial magnetic stimulation (TMS). This included resting motor threshold (rMT), paired-pulse measurements of intracortical inhibition and facilitation (ICI and ICF), recruitment curve (RC), and silent period (SP). We also measured F response and compound muscle action potential (CMAP) with peripheral nerve stimulation. The study was carried out using a randomized, double-blind crossover design controlled with a saline infusion.

RESULTS

None of the measures of cortical or peripheral excitability were significantly affected by drug administration.

CONCLUSIONS

Our findings suggest that flumazenil has no effect on cortical motor excitability in normal humans.

SIGNIFICANCE

There does not appear to be any tonic activity at benzodiazepine receptors in the normal resting human motor cortex.

Cortical control of voluntary blinking: a transcranial magnetic stimulation study

OBJECTIVE

To investigate cortical regions related to voluntary blinking.

METHODS

Transcranial magnetic stimulation (TMS) was applied to the facial motor cortex (M1) and the midline frontal region (Fz) in 10 healthy subjects with eyes opened and closed. Motor-evoked potentials were recorded from the orbicularis oculi (OOC), orbicularis oris (OOR), abductor digiti minimi and tibialis anterior using surface and needle electromyography electrodes. Facial M waves and blink reflex were measured using supramaximal electrical stimulation of the facial and supraorbital nerves.

RESULTS

TMS at Fz elicited 3 waves in OOC with no response in other tested muscles except for the early wave in OOR. Facial M1 stimulation produced only early and late waves. Because of their latencies, shapes, and relationship to coil position and stimulation intensity, early and late waves appeared to be analogous to the facial M wave and R1 component of the blink reflex. The intermediate wave at 6-8 ms latency was elicited in OOC by Fz stimulation with eyes closed.

CONCLUSIONS

Since its latency matches the central conduction time of other cranial muscles and it has characteristic of muscle activation-related facilitation, the intermediate wave is presumably related to cortical stimulation. This result provides evidence that the cortical center for the upper facial movements, including blinking, is not principally located in the facial M1, but rather in the mesial frontal region.

The effect of transcranial magnetic stimulation on movement selection

OBJECTIVE

To attempt to replicate previous findings that showed an influence of transcranial magnetic stimulation of the cortical motor areas on the selection of motor programmes on the contralateral side.

METHODS

Healthy volunteers were asked to choose to make a right or left index finger extension movement freely after hearing the click produced by transcranial magnetic stimulation. The stimulation was applied to the motor areas (test), including the motor cortex, vertex, and prefrontal cortex, and in the air (control).

RESULTS

There was no preference for choosing the hand contralateral to the stimulation site, in either test or control trials.

CONCLUSIONS

Previous results could not be reproduced. Simple magnetic stimulation of the motor areas is insufficient to affect voluntary selection of movement.

The usefulness of endoscopic hemoclipping for bleeding Dieulafoy lesions

BACKGROUND AND STUDY AIMS

Dieulafoy lesion is a rare cause of massive gastrointestinal hemorrhage, most commonly from the proximal stomach. Surgery was regarded as the treatment of choice in the past, but recently endoscopic management has become the standard approach. However, the effectiveness of various endoscopic modalities in treating bleeding Dieulafoy lesion has been little studied. This study was therefore done to compare the hemostatic efficacy of endoscopic hemoclipping and epinephrine injection therapy.

PATIENTS AND METHODS

Between January 1998 and December 2001, a consecutive series of 32 patients with bleeding Dieulafoy lesion underwent endoscopic treatment. They were randomly treated either by endoscopic epinephrine injection therapy (n = 16) or by hemoclipping (n = 16). We compared mortality rate, primary hemostasis rate, and rebleeding rate between two groups.

RESULTS

There was no bleeding-related death in either group. There was no significant difference in primary hemostasis rates between the hemoclipping group (93.8 %) and epinephrine injection group (87.5 %, P = 1.00). There was a trend toward a lower rate of need for multiple endoscopic sessions to achieve permanent hemostasis in the hemoclipping group compared with the epinephrine injection group (6.3 % vs. 31.3 %, P = 0.086). Hemoclipping was significantly more effective in preventing recurrent bleeding than epinephrine injection therapy (0 % vs. 35.7 %, P < 0.05). With regard to lesion site, hemoclipping was significantly more effective in preventing recurrent bleeding of gastric body Dieulafoy lesion than epinephrine injection therapy (0 % vs. 50 %, P < 0.05).

CONCLUSIONS

Bleeding from Dieulafoy lesion was well controlled by therapeutic endoscopic procedures. Hemoclipping was more effective for Dieulafoy lesion than epinephrine injection therapy, with less need for subsequent endoscopy.

Effect of levetiracetam on human corticospinal excitability

OBJECTIVE

To investigate whether levetiracetam (LTC) alters corticospinal excitability in humans.

BACKGROUND

Although the antiepileptic activity of LTC is well recognized, its mechanism of action has yet to be determined. Transcranial magnetic stimulation (TMS) has been used to investigate the pharmacologic effects of various antiepileptic drugs on human corticospinal excitability.

METHODS

The authors performed TMS before and after double-blind administration of 3000 mg LTC or placebo in six healthy volunteers. TMS measurements included resting and active motor threshold (MT), recruitment curve of motor-evoked potential amplitudes, intracortical inhibition, and facilitation using the paired-pulse technique and silent period. F-wave and compound muscle action potential (CMAP) were also measured.

RESULTS

In recruitment curve measurements, motor-evoked potential amplitude was reduced for LTC with high stimulation intensity (130% and 140% of resting MT) compared with placebo (p < 0.05 and p < 0.01), but not with relatively low stimulation intensity (110% and 120%). The changes in other TMS measurements as well as F-wave and CMAP after LTC did not differ significantly from those observed after placebo administration.

CONCLUSION

These results suggest that LTC reduces the corticospinal neuronal response to magnetic stimulation, preferentially affecting less excitable neurons. The lack of change in F-wave and CMAP suggests that this effect is mainly derived from the motor cortex.

The brain lesion responsible for parkinsonism after carbon monoxide poisoning

BACKGROUND

Parkinsonism is a common neurological sequela of carbon monoxide (CO) poisoning, but its pathophysiological mechanism has yet to be clarified.

OBJECTIVES

To describe a married couple who were both affected by CO poisoning, but only 1 of whom developed CO-induced parkinsonism, and to discuss the possible underlying pathophysiological mechanism of CO-induced parkinsonism by comparing the neuroimaging findings of these patients.

DESIGN AND SETTING

Case report from a clinical neurology department.

PATIENTS

A married couple experienced CO poisoning simultaneously. One month later, only the husband gradually developed delayed sequelae, including parkinsonism and intellectual impairment. On detailed neurological examination, the husband showed mild but definite rigidity and bradykinesia, while no parkinsonian signs were observed in the wife. Neuropsychological examination revealed impaired memory and attention in both patients, but they were more severe in the husband than in the wife. Magnetic resonance imaging scans of the patients' brains disclosed diffuse high-intensity white matter signals in both patients and bilateral pallidal necrosis in the wife. Dopamine transporter imaging showed that the degree of dopamine neuronal loss was comparable between these patients. Magnetic resonance spectroscopy revealed more severe white matter damage in the husband than in the wife. Thirteen months later, neurological and neuropsychological examinations showed complete recovery from parkinsonism as well as intellectual impairment. Follow-up magnetic resonance spectroscopy also suggested remarkable improvements in white matter damage.

CONCLUSION

These results support the role of white matter damage in producing parkinsonism after CO poisoning and highlight the possible usefulness of magnetic resonance spectroscopy in predicting delayed sequelae in patients after CO poisoning. Arch Neurol. 2000;57:1214-1218

Basilar artery vasospasm in postpartum cerebral angiopathy

The reason cerebral edema in postpartum cerebral angiopathy (PPCA) occurs preferentially in the posterior brain is poorly understood. The authors present two patients with PPCA who showed vasospasm occurring earlier and more severely in the basilar artery than in the middle cerebral artery. Our patients demonstrate the difference in vascular change between the anterior and posterior cerebral vessels, explaining the susceptibility of the posterior brain to PPCA.

Pure homonymous hemianopia due to anterior choroidal artery territory infarction

The most consistently observed neurological deficits in the anterior choroidal artery (AChA) territory infarction are pure motor or sensorimotor syndromes. Visual field defects and higher cortical dysfunction are occasionally accompanied, but pure homonymous hemianopia without motor and sensory symptom has never been reported yet. We present 2 patients with pure homonymous hemianopia, whose MRI disclosed cerebral infarction in the well-known territory of the AChA. In most patients with ischemic stroke, pure homonymous hemianopia indicates infarction in the posterior circulation, particularly in the posterior cerebral artery territory. However, the present cases provide evidence that it can also be caused by infarction in the anterior circulation, i.e. the AChA.

Arterial pulsatility as an index of cerebral microangiopathy in diabetes

BACKGROUND AND PURPOSE

This study was designed to evaluate cerebral hemodynamic changes related to diabetes mellitus (DM) with transcranial Doppler ultrasonography (TCD).

METHODS

We measured the flow velocities and the Gosling pulsatility index (PI) of the middle cerebral artery (MCA), extracranial internal carotid artery (ICA), and basilar artery (BA) in 56 stroke-free, normotensive patients with type 2 DM and 70 age- and gender-matched healthy volunteers. Patients were divided into 2 groups according to the presence of microvascular complications such as retinopathy, nephropathy, and neuropathy.

RESULTS

Patients showed slightly lower hematocrit and higher serum fibrinogen levels than control subjects, but other clinical profiles, including stroke risk factors except for diabetes, were comparable between patients and controls. The flow velocity of the ICA but not the MCA and BA in patients regardless of the complication was significantly higher than that in controls. The PIs of the MCA and ICA were significantly higher in patients with complication than those without complication, as well as in controls. The PI of the BA was also significantly higher, even in patients without complication, than in controls. The PIs of the MCA and ICA but not the BA were closely correlated with the duration of DM (r(2)=0.46 and 0.34, respectively).

CONCLUSIONS

This study defines TCD findings of diabetes-related cerebral hemodynamic changes and suggests that the PI reflects microangiopathic changes of cerebral vessels.

The effect of long-term levodopa therapy on depression level in de novo patients with Parkinson's disease

20) became non-depressed, while five patients (22%) among 23 initially non-depressed became depressed. With long-term levodopa therapy, the UPDRS-motor score significantly improved (35+/-15. 7-18+/-7.6), but the BDI score was unchanged (18+/-9.3-19+/-9.2). The initial BDI score was significantly and inversely correlated to the parkinsonian motor symptoms, but their percentage changes were not correlated to each other. These results provide strong support to previous observations that levodopa therapy does not alter parkinsonian depression as well as providing additional evidence to support the role of non-dopaminergic mechanisms in parkinsonian depression.

Sympathetic skin response and cardiovascular autonomic function tests in Parkinson's disease

Autonomic dysfunction commonly occurs in Parkinson's disease, but the pathogenesis of autonomic dysregulation remains uncertain. Autonomic functions regulating the cardiovascular system have been investigated in Parkinson's disease, but those involving the extremities has not been well demonstrated. To compare autonomic dysfunctions of the cardiovascular system with those of the extremities, we performed sympathetic skin response (SSR) and cardiovascular autonomic function tests (CAFT)-30 : 15 ratio, E : I ratio, Valsalva ratio, isometric exercise test (IET)--in 37 patients with Parkinson's disease and 33 age- and sex-matched healthy controls. The patients were asked to stop antiparkinsonian medications for at least 12 hours prior to the tests. SSR was measured at the right hand and foot after electrical stimulation of the right median and posterior tibial nerves. Absent SSR at either one or both extremities and CAFT beyond normal ranges were regarded as abnormal. Abnormal SSR was observed in 59% of patients, while abnormal CAFT were found in the range of 32%-81%. Patients with abnormal SSR showed more frequent and severe CAFT abnormalities than did patients with normal SSR. Among the CAFT, IET was well correlated with the SSR. The results suggest that parkinsonian sympathetic dysfunction involving either the cardiovascular system or the extremities may have the same pathophysiology.

Cerebral hemodynamic changes induced by sympathetic stimulation tests

Sympathetic neuronal activity is primarily responsible for the neurogenic control of cerebral autoregulation. The stimulation of sympathetic nerves causes both large arterial constriction and small vessel dilation in experimental animals. However, the role of the sympathetic nervous system in the control of cerebral hemodynamics has yet to be clarified in humans. In order to assess the effect of sympathetic activation on human cerebral hemodynamics, we performed a simultaneous transcranial Doppler (TCD) monitoring of bilateral middle cerebral arterial flow velocity in 16 healthy male volunteers (mean age 26) during well-known sympathetic activation measures such as isometric hand-grip exercise (IHE) and cold pressor test (CPT). Blood pressure was checked manually before and at each minute during tests. The mean arterial pressure (MAP) was calculated as (systolic pressure + 2 X diastolic pressure)/3. There was a significant increase in MCA flow velocities during both sympathetic activation tests. The percent increase of diastolic velocity (36% with IHE and 24% with CPT) was significantly higher than systolic velocity (21% with IHE and 9% with CPT). The pulsatility index was significantly decreased during the tests (from 0.75 to 0.58 with IHE and from 0.81 to 0.63 with CPT). These results suggest that sympathetic activation increases MCA flow velocities, related with a reduction in small vessel resistance and/or a constriction of large arteries.

Dopaminergic influences on the P300 abnormality in Parkinson's disease

This study was designed to evaluate the contribution of central dopaminergic mechanisms to the P300 event-related potential (P300) abnormality in Parkinson's disease. We measured the P300 in 37 non-demented patients with Parkinson's disease (19 de novo and 18 levodopa-treated) and 15 age-matched healthy volunteers. The P300 measurement was repeated in 14 de novo patients, after 6-12 months levodopa therapy. The severity of parkinsonian symptom was assessed using the UPDRS-motor scale. De novo patients showed prolonged P300 latency compared with levodopa-treated patients, as well as healthy volunteers. The levodopa therapy for 6-12 months significantly shortened the P300 latency and reduced the UPDRS-motor examination score in de novo patients. However, the percent changes in the P300 latency were not correlated with those in the UPDRS-motor examination score. These results indicate that the central dopaminergic mechanisms apart from those responsible for motor symptoms, may contribute to the P300 abnormality in Parkinson's disease.