The value of high-frequency 20 MHz ultrasonography for preoperative measurement of malignant melanoma thickness

High-frequency ultrasonography has become an important diagnostic tool in dermatovenerology. It is used for assessment of the cutaneous layers in diverse benign and malignant skin lesions and diseases. Herein we present the practical value of preoperative measurement of cutaneous melanoma thickness, the explanation of the possible reasons for different sonographic and histologic Breslow thickness, and the practical importance of high-frequency 20 MHz ultrasonography in preoperative measurements of cutaneous melanoma thickness. Fifty patients (31 women aged 41.6±15.4 years, 19 males aged 54.5±11.4 year (mean ± Standard Deviation) were examined in the Skin Cancer Clinic from January 2014 to December 2015. Suspected cutaneous melanomas were investigated with skin ultrasound Dermascan C (Cortex Technology, Denmark) before surgical removal. The Breslow thickness of cutaneous melanomas was analyzed by precise pathological examination after extirpation. Statistical analysis revealed a significant positive correlation between ultrasonographic melanoma thickness and Breslow thickness (r=0.92, P&lt;0.001). The mean thickness of invasive tumors evaluated by high frequency ultrasonography was 6.77 % higher compared with the mean Breslow thickness. The high-frequency ultrasonography provides a sensitive, noninvasive and reproducible method of skin evaluation, which enables objective visualization in vivo, providing valuable information, especially about cutaneous melanoma. The results of our study indicate that high frequency ultrasonography may be a useful adjunctive tool in the evaluation of cutaneous melanoma in daily practice.  </p

Pediatric reference values for arterial stiffness parameters cardio-ankle vascular index and CAVI0

The process of arteriosclerosis begins early in life, and cardiovascular risk factors identified in childhood tend to persist into adulthood. Cardio-ankle vascular index (CAVI), a recent parameter of arterial stiffness, is considered an independent predictor of cardiovascular risk. However, there are no studies reporting sex- and age-specific physiological values of CAVI in childhood. We aimed to establish reference values for CAVI and its blood pressure-corrected variant (CAVI0) in 500 healthy children and adolescents aged 7 to 19 years and to study potential relationships with anthropometric indices. Sex- and age-specific distributions of CAVI and CAVI0 values in healthy children and adolescents are presented. Boys aged 15-19 years had lower CAVI than girls, which could result from CAVI's slight blood pressure dependence. CAVI0 did not show such sex difference. Body roundness index-a novel parameter to quantify abdominal fat-was a strong anthropometric predictor of both CAVI and CAVI0. This is the first study providing pediatric age- and sex-specific reference values for arterial stiffness parameters CAVI and CAVI0. The presented data can contribute to the understanding of the evolution of these indices during childhood and adolescence. Under specific conditions, CAVI0 may offer more robust information about arterial stiffness than standard CAVI

User Experience May be Producing Greater Heart Rate Variability than Motor Imagery Related Control Tasks during the User-System Adaptation in Brain-Computer Interfaces

Brain-computer interface (BCI) is technology that is developing fast, but it remains inaccurate, unreliable and slow due to the difficulty to obtain precise information from the brain. Consequently, the involvement of other biosignals to decode the user control tasks has risen in importance. A traditional way to operate a BCI system is via motor imagery (MI) tasks. As imaginary movements activate similar cortical structures and vegetative mechanisms as a voluntary movement does, heart rate variability (HRV) has been proposed as a parameter to improve the detection of MI related control tasks. However, HR is very susceptible to body needs and environmental demands, and as BCI systems require high levels of attention, perceptual processing and mental workload, it is important to assess the practical effectiveness of HRV. The present study aimed to determine if brain and heart electrical signals (HRV) are modulated by MI activity used to control a BCI system, or if HRV is modulated by the user perceptions and responses that result from the operation of a BCI system (i.e., user experience). For this purpose, a database of 11 participants who were exposed to eight different situations was used. The sensory-cognitive load (intake and rejection tasks) was controlled in those situations. Two electrophysiological signals were utilized: electroencephalography and electrocardiography. From those biosignals, event-related (de-)synchronization maps and event-related HR changes were respectively estimated. The maps and the HR changes were cross-correlated in order to verify if both biosignals were modulated due to MI activity. The results suggest that HR varies according to the experience undergone by the user in a BCI working environment, and not because of the MI activity used to operate the system

COMPARISON OF HEART RATE VARIABILITY IN PATIENTS WITH PANIC DISORDER DURING COGNITIVE BEHAVIORAL THERAPY PROGRAM

Background: Many authors suggest that there is low reactivity of autonomic nervous system and reduced heart rate variability in patients with panic disorder. The patients are therefore exposed to increased cardiac mortality. Power spectral analysis is a successful tool in detecting autonomic instabilities in many disorders. Subjects and methods: The aim of our study is to monitor the activity of the autonomic nervous system through heart rate variability measured in the beginning and end of a therapeutic cognitive behavioral therapy (CBT) program in patients with panic disorder. We measured 31 patients with panic disorder in the beginning (1st measurement) and end of a therapeutic CBT program (2nd measurement). The autonomic nervous system (ANS) has been evaluated in three positions (supine – standing – supine). The evaluated parameters of the HRV linear analysis were: RR interval, HF, LF, VLF band and VLF + LF / HF ratio. Results: Spectral activity in the very low frequency band was significantly higher in the 2nd measurement compared to the 1st measurement in the standing position. The ratio of the spectral activity at lower frequencies (VLF+LF) to high frequency (HF) was significantly lower in the supine position. Conclusion: This study demonstrated an improvement of neurocardiac control regulation after a therapeutic CBT program in patients suffering from panic disorder

Measures of CNS-Autonomic Interaction and Responsiveness in Disorder of Consciousness

Neuroimaging studies have demonstrated functional interactions between autonomic (ANS) and brain (CNS) structures involved in higher brain functions, including attention and conscious processes. These interactions have been described by the Central Autonomic Network (CAN), a concept model based on the brain-heart two-way integrated interaction. Heart rate variability (HRV) measures proved reliable as non-invasive descriptors of the ANS-CNS function setup and are thought to reflect higher brain functions. Autonomic function, ANS-mediated responsiveness and the ANS-CNS interaction qualify as possible independent indicators for clinical functional assessment and prognosis in Disorders of Consciousness (DoC). HRV has proved helpful to investigate residual responsiveness in DoC and predict clinical recovery. Variability due to internal (e.g. homeostatic and circadian processes) and environmental factors remains a key independent variable and systematic research with this regard is warranted. The interest in bidirectional ANS-CNS interactions in a variety of physiopathological conditions is growing, however these interactions have not been extensively investigated in DoC. In this brief review we illustrate the potentiality of brain-heart investigation by means of HRV analysis in assessing patients with DoC. The authors’ opinion is that this easy, inexpensive and non-invasive approach may provide useful information in the clinical assessment of this challenging patient population