EEG Frequency Correlates with α2-Receptor Density in Parkinson's Disease.

INTRODUCTION: Increased theta and delta power and decreased alpha and beta power, measured with quantitative electroencephalography (EEG), have been demonstrated to have utility for predicting the development of dementia in patients with Parkinson's disease (PD). Noradrenaline modulates cortical activity and optimizes cognitive processes. We claim that the loss of noradrenaline may explain cognitive impairment and the pathological slowing of EEG waves. Here, we test the relationship between the number of noradrenergic α2 adrenoceptors and changes in the spectral EEG ratio in patients with PD. METHODS: We included nineteen patients with PD and thirteen healthy control (HC) subjects in the study. We used positron emission tomography (PET) with [11C]yohimbine to quantify α2 adrenoceptor density. We used EEG power in the delta (δ, 1.5-3.9 Hz), theta (θ, 4-7.9 Hz), alpha (α, 8-12.9 Hz) and beta (ß, 13-30 Hz) bands in regression analyses to test the relationships between α2 adrenoceptor density and EEG band power. RESULTS: PD patients had higher power in the theta and delta bands compared to the HC volunteers. Patients' theta band power was inversely correlated with α2 adrenoceptor density in the frontal cortex. In the HC subjects, age was correlated with, and occipital background rhythm frequency (BRF) was inversely correlated with, α2 adrenoceptor density in the frontal cortex, while occipital BRF was inversely correlated with α2 adrenoceptor density in the thalamus. CONCLUSIONS: The findings support the claim that the loss or dysfunction of noradrenergic neurotransmission may relate to the parallel processes of cognitive decline and EEG slowing.

Predictors for and duration of hospitalization among children and adolescents with eating disorders.

OBJECTIVE: The objective of this study was to investigate the predictive value of sex, age, body mass index (BMI), Eating Disorder Examination (EDE) score, social risk factors, and psychiatric comorbidities for hospitalization and hospitalization duration among children and adolescents suffering from eating disorders. METHOD: This prospective cohort study involved 522 consecutive patients who had been referred to a specialized eating disorder unit between January 1, 2009 and December 31, 2015; participants were followed up until August 1, 2016 by medical records. We used regression analyses to evaluate the prognostic value of sex, age, BMI, EDE, eating disorder diagnoses, social risk factors, and psychiatric comorbidities concerning inpatient hospitalization and hospitalization duration. RESULTS: We found that younger age, higher EDE global score, lower BMI percentile, anorexia nervosa, a higher number of social risk factors, and the presence of diagnosed self-harm increased the odds of being hospitalized, while being female and having a comorbid autism spectrum condition increased the duration of hospitalization. No other psychiatric comorbidity was found to significantly predict hospitalization or duration of hospitalization. DISCUSSION: The odds of being hospitalized were predicted by the severity of anorexia nervosa and indicators of social risk factors in the family, whereas the duration of hospitalization was predicted by having a comorbid autism spectrum condition, indicating a difference between the factors affecting the risk of hospitalization and the factors affecting the duration of hospitalization. This calls for further exploration of tailored treatments for eating disorders. PUBLIC SIGNIFICANCE STATEMENT: This study finds that hospitalization for an eating disorder is predicted by the severity of the illness, self-harm, and social risk factors. Duration of hospitalization is predicted by having a comorbid autism spectrum condition. These findings indicate that the treatment of eating disorders may require different treatment approaches depending on the presentation of the individual patient to reduce both the need for hospitalization and the length of inpatient stay.

Standard versus reduced dose of antipsychotics for relapse prevention in multi-episode schizophrenia: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Dose reduction of antipsychotic maintenance treatment in individuals with schizophrenia could be desirable to minimise adverse effects, but evidence for this strategy is unclear. We aimed to compare risks and benefits of reduced versus standard doses of antipsychotics. METHODS: We searched Embase, Medline, PsycINFO, and the Cochrane Library from database inception until June 17, 2020, for randomised trials in adults with schizophrenia or schizoaffective disorder lasting at least 24 weeks, including individuals clinically stable at baseline, and comparing at least two doses of the same antipsychotic, excluding trials in first-episode psychosis or treatment-resistant schizophrenia. We compared low-dose (within 50-99% of the lower limit of the standard dose) and very-low dose (less than 50% of the lower limit) with standard dose, defined as doses higher than the lower limit of the treatment dose recommended by the International Consensus Study. Data from published reports on number of participants, treatment, sex, age, number of events, and changes in psychopathology scores were extracted independently by at least two authors. Investigators or sponsors were contacted by email to obtain missing information regarding outcomes. Co-primary outcomes were relapse and all-cause discontinuation. Study-level data were meta-analysed using random-effects models, calculating risk ratios (RRs) for dichotomous data, and Hedges' g for continuous data. The protocol was registered with OSF registries. FINDINGS: 7853 references were identified in the database search and one additional reference from a manual review of relevant studies. 5744 abstracts were assessed for eligibility, and 101 references were assessed for full-text review. Of these, 79 were excluded for a variety of reasons, resulting in 22 studies being included in the meta-analysis, reporting on 24 trials and 3282 individuals. Study participants had a median age of 38 years (IQR 36-40) with 2166 (65·9%) males and 1116 (34·0%) females. Compared with standard dose, low dose increased the risk of relapse by 44% (16 trials, 1920 participants; RR 1·44, 95% CI 1·10-1·87; p=0·0076; I2=46%) and the risk of all-cause discontinuation by 12% (16 trials, 1932 participants; RR 1·12, 1·03-1·22; p=0·0085; I2=0%). Very low dose increased the risk of relapse by 72% (13 trials, 2058 participants; RR 1·72, 95% CI 1·29-2·29; p=0·0002; I2=70%) and all-cause discontinuation by 31% (11 trials, 1866 participants; RR 1·31, 1·11-1·54; p=0·0011; I2=63%). Compared with low dose, very low dose did not significantly increase the risk of relapse (five trials, 686 participants; RR 1·31, 95% CI 0·96-1·79; p=0·092; I2=51%) or all-cause discontinuation (five trials 686 participants; RR 1·11, 95% CI 0·95-1·30; p=0·18; I2=43%). Subgroup analyses comparing double-blind versus open-label studies, first-generation versus second-generation antipsychotics, and oral versus long-acting injectable antipsychotics were consistent with the overall results. Most studies were classified as having some concerns in the risk of bias assessment, which was mainly caused by absence of publicly available study registrations. INTERPRETATION: During maintenance treatment in multi-episode schizophrenia, antipsychotic doses should probably not be reduced below the standard dose range recommended for acute stabilisation, because reducing the dose further is associated with an increased risk of both relapse and all-cause discontinuation. FUNDING: None.