Head-to-head comparison of cerebral blood flow single-photon emission computed tomography and F-18-fluoro-2-deoxyglucose positron emission tomography in the diagnosis of Alzheimer disease

BACKGROUND: Clinical diagnosis of Alzheimer disease (AD) is only 70% accurate. Reduced cerebral blood flow (CBF) and metabolism in parieto-temporal and posterior cingulate cortex may assist diagnosis. While widely accepted that 18 F-fluoro-2-deoxyglucose positron emission tomography (18 F-FDG PET) has superior accuracy to CBF-SPECT for AD, there are very limited head-to-head data from clinically relevant populations and these studies relied on clinical diagnosis as the reference standard. AIMS: To compare directly the accuracy of CBF-SPECT and 18 F-FDG PET in patients referred for diagnostic studies in detecting β-amyloid PET confirmed AD. METHODS: A total of 126 patients, 56% with mild cognitive impairment and 44% with dementia, completed both CBF-SPECT and 18 F-FDG PET as part of their diagnostic assessment, and subsequently underwent β-amyloid PET for research purposes. Transaxial slices and Neurostat 3D-SSP analyses of 18 F-FDG PET and CBF-SPECT scans were independently reviewed by five nuclear medicine clinicians blinded to all other data. Operators selected the most likely diagnosis and their diagnostic confidence. Accuracy analysis used final diagnosis incorporating β-amyloid PET as the reference standard. RESULTS: Clinicians reported high diagnostic confidence in 83% of 18 F-FDG PET compared to 67% for CBF-SPECT (P = 0.001). All reviewers showed individually higher accuracy using 18 F-FDG PET. Based on majority read, the combined area under the receiver operating characteristic curve in diagnosing AD was 0.71 for 18 F-FDG PET and 0.61 for CBF-SPECT (P = 0.02). The sensitivity of 18 F-FDG PET and CBF-SPECT was 76% versus 43% (P < 0.001), while specificity was 74% versus 83% (P = 0.45). CONCLUSIONS: 18 F-FDG PET is superior to CBF-SPECT in detecting AD among patients referred for the assessment of cognitive impairment

Clinical utility of mental state screening as a predictor of intellectual outcomes 6 months after diagnosis of type 1 diabetes

Background Screening tests of basic cognitive status or ‘mental state’ have been shown to predict mortality and functional outcomes in adults. This study examined the relationship between mental state and outcomes in children with type 1 diabetes. Objective We aimed to determine whether mental state at diagnosis predicts longer term cognitive function of children with a new diagnosis of type 1 diabetes. Methods Mental state of 87 patients presenting with newly diagnosed type 1 diabetes was assessed using the School-Years Screening Test for the Evaluation of Mental Status. Cognitive abilities were assessed 1 wk and 6 months postdiagnosis using standardized tests of attention, memory, and intelligence. Results Thirty-seven children (42.5%) had reduced mental state at diagnosis. Children with impaired mental state had poorer attention and memory in the week following diagnosis, and, after controlling for possible confounding factors, significantly lower IQ at 6 months compared to those with unimpaired mental state (p < 0.05). Conclusions Cognition is impaired acutely in a significant number of children presenting with newly diagnosed type 1 diabetes. Mental state screening is an effective method of identifying children at risk of ongoing cognitive difficulties in the days and months following diagnosis. Clinicians may consider mental state screening for all newly diagnosed diabetic children to identify those at risk of cognitive sequelae

Neurobehavioral consequences of prenatal antiepileptic drug exposure

Despite elevated rates of birth defects associated with prenatal antiepileptic drug exposure, pharmacotherapy is typically continued throughout pregnancy because of the risks posed to mother and child by recurrent seizures. Emerging data suggest that prenatal exposure to valproate or polytherapy may also be associated with increased risk of cognitive impairment. However, our understanding of the longer-term sequelae of prenatal antiepileptic drug exposure remains incomplete. Improved understanding of the neurobehavioral consequences of prenatal antiepileptic drug exposure is essential to ensure accurate information is available for women with epilepsy planning a pregnancy, and to achieve optimal outcomes for mothers and children

Diabetic ketoacidosis and electroencephalographic changes in newly diagnosed pediatric patients

Objective: To document electroencephalogram (EEG) changes and their correlation with clinical parameters in a newly diagnosed pediatric cohort of type 1 diabetes mellitus (T1DM) patients with and without diabetic ketoacidosis (DKA) and to define their medium term utility and significance.\ud \ud Research design and methods: Prospective longitudinal study of children presenting with T1DM. EEGs were performed within 24 h of diagnosis, day 5, and at 6 months post-diagnosis and reviewed by a neurologist blinded to clinical status. Severity of encephalopathy was graded from 1 to 5 using the Aoki and Lombroso encephalopathy scale. Cognitive abilities were assessed using standardized tests of attention, memory, and intelligence.\ud \ud Results: Eighty eight children were recruited; 34 presented with DKA. Abnormal background slowing was more often observed in the first 24 h in children with DKA (p = 0.01). Encephalopathy scores on day 1 correlated with initial pH, CO2, HCO3, base excess, respiratory rate, heart rate, diastolic blood pressure, and IV fluid intake (all parameters p < 0.05). EEG scores at day 1 did not correlate with contemporaneous mental state or cognition in the medium term.\ud \ud Conclusions: DKA was associated with significant clinical and neurophysiologic signs of brain dysfunction at presentation. While EEG is sensitive to the detection of encephalopathy in newly diagnosed T1DM, it has limited use in identifying children at risk of later cognitive deficits

Per- and poly-fluoroalkyl substances (PFAS): Current status and research needs

An expert workshop focusing on per- and poly-fluoroalkyl substances (PFAS) was held in Adelaide, South Australia, Australia in September 2019 following the 8th International Contaminated Site Remediation Conference — CleanUp 2019. The workshop was organised by the Cooperative Research Centre for Contamination and Remediation of the Environment (CRC CARE) and was chaired by Professor Ravi Naidu, CEO and Managing Director of CRC CARE and Director of the Global Centre for Environmental Remediation at the University of Newcastle, NSW. The purpose of the workshop, which was attended by more than 50 experts in the field of contaminated land assessment and management, was to discuss the current state of play and research needs relating to PFAS contaminated sites. This paper provides a summary of the discussions and conclusions and lists actions and needs that the expert group identified as critical for pursuing successful PFAS management and remedy approaches. This paper is intended to capture the shared information, comments, and current thinking related to PFAS challenges and research needs as identified by the group of expert participants; the write up is not intended to be a complete dissertation on the science and work that has been carried out. With a fast-evolving subject and increased government and public attention on PFAS presence in the environment, the group was convened with the objective of providing value in contributing to solutions to the PFAS challenges that are faced both in Australia and internationally. The text contained herein provides references to observations and methods that the experts drew on in their discussions and in support of their commentary; documentation of the original references was not provided, and the reader should consult the scientific literature if further information and confirmation of observations is required. Following a brief on the background to PFAS challenges, the paper focusses on research gaps identified by experts with focus on Australian soils and groundwater including climatic patterns, an overview of PFAS research in Australia with emphasis on: • Regulatory • Analytical considerations • Ecological and Human Health Risks • Fate and Transport • Remediation and Risk Management