[Effects of transcranial direct current stimulation on cognitive function in delayed encephalopathy after carbon monoxide poisoning].

Objective: To investigate the effect of transcranial direct current stimulation (tDCS) on cognitive function of delayed encephalopathy after carbon monoxide poisoning (DEACMP) . Methods: A total of 58 patients with DEACMP admitted to the Emergency Medicine Department of Hudson International Peace Hospital from January 2018 to January 2020 were included. According to the random number table, the patients were randomly divided into study group and control group, with 29 patients in each group. Patients in both groups were given nutritional nerve therapy, improved microcirculation, adrenal cortical hormone and other drugs, as well as hyperbaric oxygen and rehabilitation training, once per day. The study group was treated with tDCS (electrode pads were placed and current stimulation was given 30 min/time) 1/d on the basis of conventional treatment, while the control group was treated with tDCS pseudo stimulation (electrode pads were placed and current stimulation was given for 10 s) 1/d for 30 days consecutively. The auditory event-related potential P300 (ERP-P300) was tested before and 30 days after treatment, and the Mini-Mental State Examination (MMSE) scale, Barthel index (BI) and the National Institutes of Health Neurological Impairment score (NIHSS) were used to evaluate and analyze the patients. Results: There was no significant difference in scores between the two groups before treatment (all P>0.05) . After 30 days of treatment, the MMSE score, orientation, memory, attention and computing power, and language ability of the study group were all higher than those of the control group, and the differences were statistically significant (P<0.05) . 90 days after treatment, the BI of the study group was higher than that of the control group (P<0.05) . After 30 days of treatment, the NIHSS score of the study group was significantly lower than that of the control group (P<0.05) . The latency of ERP-P300 in the study group was shorter than that in the control group, and the amplitude was higher than that in the control group at 30 days after treatment, and the difference was statistically significant (P<0.05) . The latency of ERP-P300 was negatively correlated with the total MMSE score before and after DEACMP treatment (r=-0.837, -0.819, P<0.05) . The latency of ERP-P300 was negatively correlated with orientation, attention and computing power, and language ability before treatment (r=-0.698, -0.675, -0.742, P<0.05) . Conclusion: TDCS treatment can help improve the cognitive function of DEACMP patients, and ERP-P300 test can help determine the cognitive function severity of patients.

Neural Activities Classification of Human Inhibitory Control Using Hierarchical Model.

Human inhibitory control refers to the suppression of behavioral response in real environments, such as when driving a car or riding a motorcycle, playing a game and operating a machine. The P300 wave is a neural marker of human inhibitory control, and it can be used to recognize the symptoms of attention deficit hyperactivity disorder (ADHD) in human. In addition, the P300 neural marker can be considered as a stop command in the brain-computer interface (BCI) technologies. Therefore, the present study of electroencephalography (EEG) recognizes the mindset of human inhibition by observing the brain dynamics, like P300 wave in the frontal lobe, supplementary motor area, and in the right temporoparietal junction of the brain, all of them have been associated with response inhibition. Our work developed a hierarchical classification model to identify the neural activities of human inhibition. To accomplish this goal phase-locking value (PLV) method was used to select coupled brain regions related to inhibition because this method has demonstrated the best performance of the classification system. The PLVs were used with pattern recognition algorithms to classify a successful-stop versus a failed-stop in left-and right-hand inhibitions. The results demonstrate that quadratic discriminant analysis (QDA) yielded an average classification accuracy of 94.44%. These findings implicate the neural activities of human inhibition can be utilized as a stop command in BCI technologies, as well as to identify the symptoms of ADHD patients in clinical research.

Neuropsychological and neurophysiological benefits from white noise in children with and without ADHD.

BACKGROUND: Optimal stimulation theory and moderate brain arousal (MBA) model hypothesize that extra-task stimulation (e.g. white noise) could improve cognitive functions of children with attention-deficit/hyperactivity disorder (ADHD). We investigate benefits of white noise on attention and inhibition in children with and without ADHD (7-12 years old), both at behavioral and at neurophysiological levels. METHODS: Thirty children with and without ADHD performed a visual cued Go/Nogo task in two conditions (white noise or no-noise exposure), in which behavioral and P300 (mean amplitudes) data were analyzed. Spontaneous eye-blink rates were also recorded and participants went through neuropsychological assessment. Two separate analyses were conducted with each child separately assigned into two groups (1) ADHD or typically developing children (TDC), and (2) noise beneficiaries or non-beneficiaries according to the observed performance during the experiment. This latest categorization, based on a new index we called "Noise Benefits Index" (NBI), was proposed to determine a neuropsychological profile positively sensitive to noise. RESULTS: Noise exposure reduced omission rate in children with ADHD, who were no longer different from TDC. Eye-blink rate was higher in children with ADHD but was not modulated by white noise. NBI indicated a significant relationship between ADHD and noise benefit. Strong correlations were observed between noise benefit and neuropsychological weaknesses in vigilance and inhibition. Participants who benefited from noise had an increased Go P300 in the noise condition. CONCLUSION: The improvement of children with ADHD with white noise supports both optimal stimulation theory and MBA model. However, eye-blink rate results question the dopaminergic hypothesis in the latter. The NBI evidenced a profile positively sensitive to noise, related with ADHD, and associated with weaker cognitive control.

Association between P300 parameters and cognitive function in people with diabetic neuropathy.

Purpose: The purpose of this study was to investigate the association between event-related potential (ERP) P300 with cognitive function in people with diabetic peripheral neuropathy (DPN). Methods: We performed a cross-sectional analysis of 19 type 2 diabetes mellitus (T2DM) patients, aged 18 and older with DPN. The participants were assessed for neuropathy, cognitive function, & dual-task performance. DPN was examined via the administration of diabetic neuropathy symptom score (DNSS) and vibration perception threshold (VPT). Cognitive dysfunction was evaluated using Mini-mental state examination (MMSE), trail making test-B (TMT-B), and ERP P300 wave latency & amplitude. For assessing dual-task performance, the dual-task cost (DTC) was calculated using the timed-up and go (TUG) test and TUG with dual task (TUG-DT). Results: P300 latency was linearly related to TMT-B (R = 0.31, p = 0.01) and DTC (R = 0.22, p = 0.04). A similar trend was observed in TMT-B (R = 0.13, p = 0.04) & DTC (R =0 .67, p = 0.001) with respect to P300 amplitude. MMSE did not relate with P300 latency (R = 0.14, p = 0.58) & amplitude (R = 0.63, p = .44). Conclusion: P300 latency and amplitude are associated with cognitive function and DTC of individuals with DPN.

Long-term neurological sequelae after decompression sickness in retired professional divers.

INTRODUCTION: Decompression sickness (DCS) has traditionally been categorized as type I DCS, affecting joints and skin, and type II affecting the nervous system. In the present study, we wanted to examine whether divers with a history of neurological DCS demonstrated a pattern of symptoms and clinical neurological and neurophysiological signs different from divers with other manifestations of DCS or no history of DCS. METHODS: Up to 1990, 365 Norwegian offshore divers worked in the North Sea. Two hundred and eight divers who had performed saturation diving, bounce diving or both, were included in this study. They filled in a questionnaire for registration of diving experience and health complaints, and episodes of DCS were registered. All participants had a clinical neurological and neurophysiological examination (ERP- P300). RESULTS: One hundred and sixty three of the 208 divers (78.4%) reported episodes of DCS. Neurological DCS was reported by 41 (19.7%) divers. Forty-five divers (21.6%) reported no episodes of DCS. Divers who reported episodes of DCS reported significantly more symptoms compared with divers who reported no DCS. Divers who reported neurological DCS had significantly more neurological findings on motility tests, sensory tests and coordination/cerebellar tests. The P300 motor reaction times were significantly longer in divers reporting DCS, but there was no significant difference between divers with neurological DCS and divers with other forms of DCS. CONCLUSIONS: This study indicates that DCS is associated with long-term effects on the nervous system independent of the symptomatology in the acute stage.

Electro-physiological changes in the brain induced by caffeine or glucose nasal spray.

OBJECTIVE: A direct link between the mouth cavity and the brain for glucose (GLUC) and caffeine (CAF) has been established. The aim of this study is to determine whether a direct link for both substrates also exist between the nasal cavity and the brain. METHODS: Ten healthy male subjects (age 22 ± 1 years) performed three experimental trials, separated by at least 2 days. Each trial included a 20-s nasal spray (NAS) period in which solutions placebo (PLAC), GLUC, or CAF were provided in a double-blind, randomized order. During each trial, four cognitive Stroop tasks were performed: two familiarization trials and one pre- and one post-NAS trial. Reaction times and accuracy for different stimuli (neutral, NEUTR; congruent, CON; incongruent INCON) were determined. Electroencephalography was continuously measured throughout the trials. During the Stroop tasks pre- and post-NAS, the P300 was assessed and during NAS, source localization was performed using standardized low-resolution brain electromagnetic tomography (sLORETA). RESULTS AND DISCUSSION: NAS activated the anterior cingulate cortex (ACC). CAF-NAS also increased θ and ß activity in frontal cortices. Furthermore, GLUC-NAS increased the ß activity within the insula. GLUC-NAS also increased the P300 amplitude with INCON (P = 0.046) and reduced P300 amplitude at F3-F4 and P300 latency at CP1-CP2-Cz with NEUTR (P = 0.001 and P = 0.016, respectively). The existence of nasal bitter and sweet taste receptors possibly induce these brain responses. CONCLUSION: Greater cognitive efficiency was observed with GLUC-NAS. CAF-NAS activated cingulate, insular, and sensorymotor cortices, whereas GLUC-NAS activated sensory, cingulate, and insular cortices. However, no effect on the Stroop task was found.

Impulsive violent criminals and predictive violent criminals: an event-related potential P300 study / 中华行为医学与脑科学杂志

Objective To compare the amplitude and latency of event-related potential P300 be-tween impulsive and predictive violent criminals. Methods Twenty impulsive violent criminals and twenty predictive violent criminals were recruited from one prison in Wenzhou city. Twenty matched healthy controls from community were recruited. Criminals in both groups were excluded from violent crimes caused by mental disorders by judicial psychiatrists using DSM-IV axis I disorder clinical stereotyped interviews. Nicolet Bravo Brain Evoked Potentiometer (produced by Nicolet Company,USA) was used to detect the P300 components of the above three groups of subjects. Eysenck Impulsiveness Scale was used to assess the impulsiveness. Results The P300 amplitude of impulsive violent criminals was smaller than that of predictive violent crimi-nals( (4. 52±1. 14)μV vs (13. 88±2. 06)μV,t=17. 779,P<0. 01),but there was no significant difference of the P300 amplitude between predictive violent criminals and community enrolled controls ((13. 88±2. 06) μV vs (14. 01±1. 86)μV,t=0. 209,P=0. 835). The impulsivity scale score of impulsive violent criminals was highly negatively correlated with the amplitude of P300 (r=-0. 812,P=0. 002). There were no signifi-cant differences in the latency of P300 among impulsive violent criminals,predictive violent criminals and community enrolled controls group. And there was no significant correlation between the latency of P300 and the score of impulsivity scale (P>0. 05). Conclusion The P300 amplitude can aid in the differential diag-nosis of violent criminals with and without impulsive behavior.