Julian N. Trollor

A review of the association between obesity and cognitive function across the lifespan : implications for novel approaches to prevention and treatment

Recent research suggests that increased adiposity is associated with poor cognitive performance, independently of associated medical conditions. The evidence regarding this relationship is examined in this review article. A relatively consistent finding across the lifespan is that obesity is associated with cognitive deficits, especially in executive function, in children, adolescents and adults. However, as illustrated by contradictory studies, the relationship between obesity and cognition is uncertain in the elderly, partly because of inaccuracy of body mass index as a measure of adiposity as body composition changes with aging. This review further discusses whether obesity is a cause or a consequence of these cognitive deficits, acknowledging the possible bidirectional relationship. The possible effects of increased adiposity on the brain are summarized. Our investigations suggest that weight gain results, at least in part, from a neurological predisposition characterized by reduced executive function, and in turn obesity itself has a compounding negative impact on the brain via mechanisms currently attributed to low‐grade systemic inflammation, elevated lipids and/or insulin resistance. The possible role of cognitive remediation treatment strategies to prevent and/or treat obesity is discussed.

The Sydney Memory and Ageing Study (MAS): methodology and baseline medical and neuropsychiatric characteristics of an elderly epidemiological non-demented cohort of Australians aged 70-90 years.

BACKGROUND The Sydney Memory and Ageing Study (Sydney MAS) was initiated in 2005 to examine the clinical characteristics and prevalence of mild cognitive impairment (MCI) and related syndromes, and to determine the rate of change in cognitive function over time. METHODS Non-demented community-dwelling individuals (N = 1037) aged 70-90 were recruited from two areas of Sydney, following a random approach to 8914 individuals on the electoral roll. They underwent detailed neuropsychiatric and medical assessments and donated a blood sample for clinical chemistry, proteomics and genomics. A knowledgeable informant was also interviewed. Structural MRI scans were performed on 554 individuals, and subgroups participated in studies of falls and balance, metabolic and inflammatory markers, functional MRI and prospective memory. The cohort is to be followed up with brief telephone reviews annually, and detailed assessments biannually. RESULTS This is a generally well-functioning cohort mostly living in private homes and rating their health as being better than average, although vascular risk factors are common. Most (95.5%) participants or their informants identified a cognitive difficulty, and 43.5% had impairment on at least one neuropsychological test. MCI criteria were met by 34.8%; with 19.3% qualifying for amnestic MCI, whereas 15.5% had non-amnestic MCI; 1.6% had impairment on neuropsychological test performance but no subjective complaints; and 5.8% could not be classified. The rate of MCI was 30.9% in the youngest (70-75) and 39.1% in the oldest (85-90) age bands. Rates of depression and anxiety were 7.1% and 6.9% respectively. CONCLUSIONS Cognitive complaints are common in the elderly, and nearly one in three meet criteria for MCI. Longitudinal follow-up of this cohort will delineate the progression of complaints and objective cognitive impairment, and the determinants of such change.

International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy

In order to address the major impact on quality of life and epilepsy management caused by associated neuropsychiatric conditions, an international consensus group of epileptologists met with the aim of developing clear evidence‐based and practice‐based statements to provide guidance on the management of these conditions. Using a Delphi process, this group prioritized a list of key management areas. These included: depression, anxiety, psychotic disorders, nonepileptic seizures, cognitive dysfunction, antiepileptic drug (AED)–related neurobehavioral disorders, suicidality, disorders in children and adolescents, disorders in children with intellectual disability, and epilepsy surgery. Clinical practice statements were developed for each area and consensus reached among members of the group. The assessment and management of these conditions needs to combine knowledge of psychiatric disorders, knowledge of the impact of epilepsy and its treatment on psychopathology, and an ability to deliver care within epilepsy services. The aim of these statements is to provide guidance on quality care for people with epilepsy that have a range of neuropsychiatric disorders.

Electroconvulsive Treatment of Neuroleptic Malignant Syndrome: A Review and Report of Cases

Objective: Neuroleptic malignant syndrome (NMS) is a potentially lethal adverse effect of neuroleptic medication, with no satisfactory treatment currently available. Electroconvulsive therapy (ECT) has been anecdotally reported to be effective in its treatment. We review 45 published case reports of ECT for NMS and describe nine new cases, to examine its effectiveness, the likelihood of adverse reactions, and the theoretical implications of such treatment. Method: The authors used Medline to identify reports in the English literature where ECT was used in cases of suspected NMS. In addition, the charts of patients referred to the second author for treatment of NMS were reviewed and cases in which ECT used were identified. Results: The case reports suggest that ECT is effective in many individuals with NMS, even when drug therapy has failed. The response is usually apparent after a few treatments, generally up to six. The response is not predictable on the basis of age, gender, psychiatric diagnosis or any particular feature of NMS including catatonia. Electroconvulsive therapy is a relatively safe treatment in NMS, although the risk of cardiovascular complications should be considered. Malignant hyperthermia due to the anaesthesia associated with ECT has not been reported in patients with NMS, and succinylcholine has been used safely with the exception of one report of fever and raised creatine kinase levels and another report of hyperkalemia. Conclusions: Electroconvulsive therapy is the preferred treatment in severe NMS, cases where the underlying psychiatric diagnosis is psychotic depression or catatonia, and in cases where lethal catatonia cannot be ruled out. The effectiveness of ECT for the treatment of NMS has theoretical implications for the relationship between NMS and catatonia, and the possible pathophysiological mechanisms that underlie these disorders.

Neuroleptic Malignant Syndrome Associated with Atypical Antipsychotic Drugs

Neuroleptic malignant syndrome (NMS) is a rare but potentially severe idiosyncratic adverse reaction usually seen in the context of treatment with antipsychotic drugs. Although NMS is historically associated with the classic or ‘typical’ antipsychotic drugs, it is also a potential adverse effect of atypical antipsychotic drugs. The widespread use of atypical antipsychotic drugs highlights the need to examine the data relating to the symptomatology, diagnosis, classification and management of NMS with these newer agents. We used MEDLINE and EMBASE to identify NMS case reports and systematic reviews published to June 2008 related to the atypical antipsychotic drugs clozapine, olanzapine, risperidone, paliperidone, aripiprazole, ziprasidone, amisulpride and quetiapine. Case reports and reviews were systematically examined. Our review suggests that, in general, NMS associated with atypical antipsychotic drugs manifests in a typical manner. One notable exception is clozapine-induced NMS, which appears less likely to manifest with extra-pyramidal features, including rigidity and tremor. The available literature highlights the divergence of opinion relating to the core diagnostic features of NMS and its conceptualization as a categorical versus dimensional disorder. Both these issues have relevance for the identification of atypical or milder forms of NMS, which are sometimes seen with atypical antipsychotic drugs.

Inflammatory biomarkers predict depressive, but not anxiety symptoms during aging: The prospective Sydney Memory and Aging Study

This study addresses the paucity of research on the prospective relationship between a range of inflammatory markers and symptoms of depression and anxiety during aging. In the Sydney Memory and Aging Study, the relationships between remitted depression, current and first onset of symptoms of depression or anxiety (Geriatric Depression Scale and Goldberg Anxiety Scale (GDS, GAS), and markers of systemic inflammation (C-reactive protein (CRP), interleukins-1β, -6, -8, -10, -12, plasminogen activator inhibitor-1 (PAI-1), serum amyloid A, tumor necrosis factor-α, and vascular adhesion molecule-1) were investigated. The sample consists of N=1037 non-demented community-dwelling elderly participants aged 70-90 years assessed at baseline and after 2-years. All analyses were adjusted for gender, age, years of education, total number of medical disorders diagnosed by a doctor, cardiovascular disorders, endocrine disorders, smoking, body mass index, currently using anti-depressants, NSAIDS or statins and diabetes mellitus. The results show a significant linear relationship between increasing levels of IL-6 and depressive symptoms at baseline only, whereas IL-8 was associated with depressed symptoms at baseline and at 2 years follow-up. In addition, IL-8 was associated with first onset of mild to moderate depressive symptoms over 2 years. Logistic regression analyses showed that PAI-1 (OR=1.37, 95% CI=1.10-1.71, p=0.005) was associated with remitted depression. Results for anxiety symptoms were negative. The findings are suggestive of IL-6 and IL-8 being associated with current symptoms and IL-8 being associated with first onset of depressive symptoms, whereas PAI-1 could be regarded as a marker of remitted depression.

White matter integrity in mild cognitive impairment: A tract-based spatial statistics study

Mild cognitive impairment (MCI) as a clinical diagnosis has limited specificity, and identifying imaging biomarkers may improve its predictive validity as a pre-dementia syndrome. This study used diffusion tensor imaging (DTI) to detect white matter (WM) structural alterations in MCI and its subtypes, and aimed to examine if DTI can serve as a potential imaging marker of MCI. We studied 96 amnestic MCI (aMCI), 69 non-amnestic MCI (naMCI), and 252 cognitively normal (CN) controls. DTI was performed to measure fractional anisotropy (FA), and tract-based spatial statistics (TBSS) were applied to investigate the characteristics of WM changes in aMCI and naMCI. The diagnostic utility of DTI in distinguishing MCI from CN was further evaluated by using a binary logistic regression model. We found that FA was significantly reduced in aMCI and naMCI when compared with CN. For aMCI subjects, decreased FA was seen in the frontal, temporal, parietal, and occipital WM, together with several commissural, association, and projection fibres. The best discrimination between aMCI and controls was achieved by combining FA measures of the splenium of corpus callosum and crus of fornix, with accuracy of 74.8% (sensitivity 71.0%, specificity 76.2%). For naMCI subjects, WM abnormality was more anatomically widespread, but the temporal lobe WM was relatively spared. These results suggest that aMCI is best characterized by pathology consistent with early Alzheimers disease, whereas underlying pathology in naMCI is more heterogeneous, and DTI analysis of white matter structural integrity can serve as a potential biomarker of MCI and its subtypes.

An international consensus study of neuroleptic malignant syndrome diagnostic criteria using the Delphi method.

OBJECTIVE The lack of generally accepted diagnostic criteria for neuroleptic malignant syndrome (NMS) impedes research and clinical management of patients receiving antipsychotic medications. The purpose of this study was to develop NMS diagnostic criteria reflecting a broad consensus among clinical knowledge experts, represented by an international multispecialty physician panel. PARTICIPANTS Eleven psychiatrists, 2 neurologists, 2 anesthesiologists, and 2 emergency medicine specialists participated in a formal Delphi consensus procedure. EVIDENCE A core bibliography consisting of 12 prominent, current reviews of the NMS literature was identified by an objective, comprehensive electronic search strategy. Each panel member was given a copy of these references and asked to examine them before commencing the survey process. CONSENSUS PROCESS After reviewing the core bibliography, panel members were asked to list any clinical signs or symptoms or diagnostic studies that they believed, on the basis of their knowledge and clinical experience, were useful in making a diagnosis of NMS. In subsequent survey rounds, panel members assigned priority points to these items, and items that failed to receive a minimum priority score were eliminated from the next round. Information about individual panel member responses was fed back to the group anonymously in the form of the group median or mean and the number of members who had ranked or scored each survey item. The a priori consensus endpoint was defined operationally as a change of 10% or less in the mean priority score for any individual item, and an average absolute value change of 5% or less across all items, between consecutive rounds. The survey was conducted from January 2009 through September 2009. RESULTS Consensus was reached on the fifth round regarding the following criteria: recent dopamine antagonist exposure, or dopamine agonist withdrawal; hyperthermia; rigidity; mental status alteration; creatine kinase elevation; sympathetic nervous system lability; tachycardia plus tachypnea; and a negative work-up for other causes. The panel also reached a consensus on the relative importance of these criteria and on the following critical values for quantitative criteria: hyperthermia, > 100.4°F or > 38.0°C on at least 2 occasions; creatine kinase elevation, at least 4 times the upper limit of normal; blood pressure elevation, ≥ 25% above baseline; blood pressure fluctuation, ≥ 20 mm Hg (diastolic) or ≥ 25 mm Hg (systolic) change within 24 hours; tachycardia, ≥ 25% above baseline; and tachypnea, ≥ 50% above baseline. CONCLUSIONS These diagnostic criteria significantly advance the field because they represent the consensus of an international multispecialty expert panel, include critical values, provide guidance regarding the relative importance of individual elements, and are less influenced by particular theoretical biases than most previously published criteria. They require validation before being applied in clinical settings.

Mild cognitive impairment in a community sample: The Sydney Memory and Ageing Study

Mild cognitive impairment (MCI) is associated with an increased dementia risk. This study reports incidence of MCI subtypes, rates of progression to dementia, and stability of MCI classification.

Microstructural white matter changes in cognitively normal individuals at risk of amnestic MCI

Objective: Since Alzheimer disease (AD) is a slowly progressive disorder and its pathologic features are likely to be present for many years before symptoms become manifest, we investigated whether microstructural white matter changes similar to those identified in patients with AD can be detected in cognitively normal individuals without dementia destined to develop amnestic mild cognitive impairment (aMCI). Methods: We studied 193 cognitively normal individuals, of whom 173 remained cognitively stable (CN-stable) and 20 were diagnosed with aMCI (CN-aMCI converter) 2 years later. Structural MRI and diffusion tensor imaging were acquired at baseline to assess gray matter atrophy and microstructural white matter changes, respectively. Results: At baseline, compared with CN-stable, CN-aMCI converters had substantial reductions in white matter integrity in the precuneus, parahippocampal cingulum, parahippocampal gyrus white matter, and fornix. Other diffuse white matter changes were observed in the frontal, parietal, and subcortical regions, whereas gray matter structures were relatively intact. The fractional anisotropy (FA) values of the precuneus were found to be a predictor of conversion from cognitively normal to aMCI. In addition, the FA values of the left parahippocampal gyrus white matter were predictive of subsequent episodic memory decline. Conclusions: Microstructural white matter changes are present in cognitively normal individuals in the pre-aMCI stage, and may serve as a potential imaging marker of early AD-related brain changes.