ABSTRACT.Purpose: To determine alterations in the retina of patients with Alzheimer's disease (AD) by the newly developed technique of fluorescence lifetime imaging ophthalmoscopy (FLIO) in a pilot study. Methods: FLIO set-up uses a scanning laser ophthalmoscope (HRA2, Heidelberg Engineering, Germany), which was modified by the use of an excitation pulse laser BLD440 (Becker&Hickl, Berlin, Germany) and detection of fluorescence lifetime by time-correlated single photon counting (TCSPC; Becker&Hickl) in two spectral channels (channel 1: 490-560 nm, channel 2: 560-700 nm). Least square fit of three exponential functions was used for fluorescence decay analysis. That resulted in three fluorescent components with lifetimes s i , amplitudes a i and relative contributions Q i . 16 patients with AD (mean age 77.2 AE 7.0 years) were investigated. After regular ophthalmic investigation, FLIO examination and OCT examination were performed. Alzheimer-specific clinical data were collected (MMSE, cerebrospinal fluid (CSF) concentration of amyloid-b (1-42), total-tau and phosphorylated tau181 (p-tau181) protein). Results: The FLIO parameters of the second fluorescent component a 2 and Q 2 (channel 2) correlated significantly with MMSE score (Q 2 , R = À0.757, p = 0.007; a 2 , R = À0.618, p = 0.043) as well as p-tau181-protein concentration in CSF (Q 2 , R = 0.919, p = 0.009; a 2 , R = 0.881, p = 0.020) in patients with AD. OCT measurements of retinal nerve fibre layer thickness, optic disc excavation and macular thickness neither correlated with Alzheimer-specific CSF data nor MMSE score. Conclusions: Unlike conventional techniques, such as OCT, the new technique of FLIO revealed changes in the retina of patients with AD in relation to Alzheimer-specific markers in this pilot study.
The pattern of linear heart rate variability we found in mid stage HD patients points towards a predominately reduced cardiovagal modulation compared with healthy subjects, which might influence HD patients' susceptibility for cardiovascular complications such as syncopes and cardiac arrhythmias.
Elite young athletes have to cope with multiple psychological demands such as training volume, mental and physical fatigue, spatial separation of family and friends or time management problems may lead to reduced mental and physical recovery. While normative data regarding symptoms of anxiety and depression for the general population is available (Hinz and Brähler, 2011), hardly any information exists for adolescents in general and young athletes in particular. Therefore, the aim of this study was to assess overall symptoms of anxiety and depression in young athletes as well as possible sex differences. The survey was carried out within the scope of the study “Resistance Training in Young Athletes” (KINGS-Study). Between August 2015 and September 2016, 326 young athletes aged (mean ± SD) 14.3 ± 1.6 years completed the Hospital Anxiety and Depression Scale (HAD Scale). Regarding the analysis of age on the anxiety and depression subscales, age groups were classified as follows: late childhood (12–14 years) and late adolescence (15–18 years). The participating young athletes were recruited from Olympic weight lifting, handball, judo, track and field athletics, boxing, soccer, gymnastics, ice speed skating, volleyball, and rowing. Anxiety and depression scores were (mean ± SD) 4.3 ± 3.0 and 2.8 ± 2.9, respectively. In the subscale anxiety, 22 cases (6.7%) showed subclinical scores and 11 cases (3.4%) showed clinical relevant score values. When analyzing the depression subscale, 31 cases (9.5%) showed subclinical score values and 12 cases (3.7%) showed clinically important values. No significant differences were found between male and female athletes (p ≥ 0.05). No statistically significant differences in the HADS scores were found between male athletes of late childhood and late adolescents (p ≥ 0.05). To the best of our knowledge, this is the first report describing questionnaire based indicators of symptoms of anxiety and depression in young athletes. Our data implies the need for sports medical as well as sports psychiatric support for young athletes. In addition, our results demonstrated that the chronological classification concerning age did not influence HAD Scale outcomes. Future research should focus on sports medical and sports psychiatric interventional approaches with the goal to prevent anxiety and depression as well as teaching coping strategies to young athletes.
The majority of excess mortality among people with schizophrenia seems to be caused by cardiovascular complications, and in particular, coronary heart disease. In addition, the prevalence of heart failure and arrhythmias is increased in this population. Reduced efferent vagal activity, which has been consistently described in these patients and their healthy first-degree relatives, might be one important mechanism contributing to their increased cardiac mortality. A decrease in heart rate variability and complexity was often shown in unmedicated patients when compared to healthy controls. In addition, faster breathing rates, accompanied by shallow breathing, seem to influence autonomic cardiac functioning in acute unmedicated patients substantially. Moreover, low-physical fitness is a further and independent cardiac risk factor present in this patient population. Interestingly, new studies describe chronotropic incompetence during physical exercise as an important additional risk factor in patients with schizophrenia. Some studies report a correlation of the autonomic imbalance with the degree of positive symptoms (i.e., delusions) and some with the duration of disease. The main body of psychiatric research is focused on mental aspects of the disease, thereby neglecting obvious physical health needs of these patients. Here, a joint effort is needed to design interventional strategies in everyday clinical settings to improve physical health and quality of life.
Pupillary unrest is an established indicator of drowsiness or sleepiness. How sympathetic and parasympathetic activity contribute to pupillary unrest is not entirely unclear. In this study, we investigated 83 young healthy volunteers to assess the relationship of pupillary unrest to other markers of the autonomic nervous system. Sample entropy (SE) and the established pupillary unrest index (PUI) were calculated to characterize pupil size variability. Autonomic indices were derived from heart rate, blood pressure, respiration, and skin conductance. Additionally, we assessed individual levels of calmness, vigilance, and mood. In an independent sample of 26 healthy participants, we stimulated the cardiovagal system by a deep breathing test. PUI was related to parasympathetic cardiac indices and sleepiness. A linear combination of vagal heart rate variability [root mean square of heart beat interval differences (RMSSD)] and skin conductance fluctuations (SCFs) was suited best to explain interindividual variance of PUI. Complexity of pupil diameter (PD) variations correlated to indices of sympathetic skin conductance. Furthermore, we found that spontaneous fluctuations of skin conductance are accompanied by increases of pupil size. In an independent sample, we were able to corroborate the relation of PUI with RMSSD and skin conductance. A slow breathing test enhanced RMSSD and PUI proportionally to each other, while complexity of PD dynamics decreased. Our data suggest that the slow PD oscillations (f < 0.15 Hz) quantified by PUI are related to the parasympathetic modulation. Sympathetic arousal as detected by SCFs is associated to transient pupil size increases that increase non-linear pupillary dynamics.
Previous studies have shown that untreated patients with acute schizophrenia present with reduced heart rate variability and complexity as well as increased QT variability. This autonomic dysregulation might contribute to increased cardiac morbidity and mortality in these patients. However, the additional effects of newer antipsychotics on autonomic dysfunction have not been investigated, applying these new cardiac parameters to gain information about the regulation at sinus node level as well as the susceptibility to arrhythmias.We have investigated 15 patients with acute schizophrenia before and after established olanzapine treatment and compared them with matched controls. New nonlinear parameters (approximate entropy, compression entropy, fractal dimension) of heart rate variability and also the QT-variability index were calculated.In accordance with previous results, we have observed reduced complexity of heart rate regulation in untreated patients. Furthermore, the QT-variability index was significantly increased in unmedicated patients, indicating increased repolarization lability. Reduction of the heart rate regulation complexity after olanzapine treatment was seen, as measured by compression entropy of heart rate. No change in QT variability was observed after treatment.This study shows that unmedicated patients with acute schizophrenia experience autonomic dysfunction. Olanzapine treatment seems to have very little additional impact in regard to the QT variability. However, the decrease in heart rate complexity after olanzapine treatment suggests decreased cardiac vagal function, which may increase the risk for cardiac mortality. Further studies are warranted to gain more insight into cardiac regulation in schizophrenia and the effect of novel antipsychotics. (J Clin Psychopharmacol 2008;28:694-698)
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