Assessment of visual and auditory evoked potentials in young obese males.

Background: Obesity is a chronic condition, affecting central and peripheral nervous system. Studies on cranial nerve conduction in obesity are scarce and unclear; therefore, we planned this study. The aim of this study was to evaluate optic and auditory nerve conductions in obesity. Methods: It was a case-control study, with inclusion of 40 young males (20 obese and 20 controls) in age group of 18-30 years. We recorded pattern reversal visual evoked potential (PRVEP) and brainstem auditory evoked potential (BAEP). The PRVEP P100 latency and BAEP absolute and interpeak latencies were analyzed. Results: In obese individuals, BAEP absolute latencies of wave V were significantly prolonged in both the ears and wave I in left ear. In addition, significant prolongation of interpeak latency III-V was observed in both the ears and I-V latency, in right ear among obese cases. A positive correlation was seen between body mass index and interpeak latency I-V. In PRVEP recordings, P100 latency did not show any significant difference in both the groups. Conclusion: Therefore, we can conclude that obesity does not affect optic nerve conduction, but auditory nerve conduction is affected. BAEP I-V interpeak latency may be an indicator of subclinical auditory conduction defects in young obese males.

Nonalcoholic Fatty Liver Disease in Shift Workers and Its Effect on Peripheral Nerve Conduction: A Cross-Sectional Study.

Introduction Nonalcoholic fatty liver disease (NAFLD) presents as a multisystem disorder, heightening the risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVDs). Occupation emerges as a significant factor influencing the occurrence of NAFLD. Research indicates that individuals engaged in shift work face an elevated risk of NAFLD, alongside obesity and T2DM, attributed to disruptions in their circadian rhythm, which precipitate hepatic steatosis and inflammation. Remarkably, peripheral neuropathy has been observed in conjunction with advanced liver disorders and NAFLD in the general population. However, the correlation between NAFLD and peripheral neuropathy remains unestablished in shift workers. Objective To identify NAFLD in seemingly healthy rotating shift workers and assess any potential impact of NAFLD on nerve function in this demographic. Methods This cross-sectional study involved 73 apparently healthy nonalcoholic security guards (aged 35 to 60 years) working in rotating shifts. The study included a comprehensive assessment, beginning with a medical history, an evaluation of physical activity, and anthropometric measurements. Confirmation of NAFLD was achieved through abdominal ultrasonography (USG), followed by the analysis of biochemical parameters. Motor and sensory nerve conduction studies (NCS) were conducted on participants with normal vitamin B12 levels using the Aleron electromyograph (EMG) machine (Recorders and Medicare Systems Private Ltd, Budanpur, India). The evaluation encompassed the Median and Common Peroneal motor nerves, as well as Median and Sural sensory nerves. Recorded parameters for motor nerves included distal motor latency (DML), compound muscle action potential (CMAP) amplitude, conduction velocity (CV), and F-wave minimum latency (F-wave), while sensory nerve parameters comprised sensory onset latency (SOL), sensory nerve action potential (SNAP) amplitude, and CV. Results Among 73 healthy security guards working in rotating shifts, 76.1% were diagnosed with NAFLD through abdominal ultrasound. Following participant withdrawals and exclusions due to vitamin B12 deficiency, a comparison of NCS parameters between NAFLD (n=24) and Non-NAFLD (n=12) groups revealed no significant disparities in motor or sensory parameters, except for a slightly diminished CMAP amplitude in the peroneal nerve of NAFLD subjects (8.21±2.83mV vs ±10.22±2.30 mV, p< 0.040). However, these differences fell within normal ranges, indicating no notable impact on peripheral nerve conduction in the presence of NAFLD. Conclusion The results indicate a high prevalence of NAFLD among individuals working rotating shifts. Moreover, the investigation suggests that despite the presence of NAFLD, there is no discernible influence on motor and sensory peripheral nerve conduction, particularly in common peroneal, median, and sural nerves.

EEG-ERP Correlates of Cognitive Dysfunction in Polycystic Ovarian Syndrome.

Background: Polycystic ovarian syndrome (PCOS) has been shown to affect the psychological and cognitive status of a woman. However, amidst various conflicting reports in this regard, very few studies attempted to assess these aspects objectively using electroencephalography (EEG) and event-related potential (ERP). Purpose: To assess changes in neurocognitive and psychological parameters of PCOS women without any other comorbidities. Methods: PCOS women aged 18 years to 35 years, diagnosed from obstetrics and gynecology OPD who are otherwise free of any other comorbidities, were assessed for psychological status (anxiety and depression using the State-Trait Anxiety Inventory and Beck Depression Inventory, respectively). Thereafter, a cognitive assessment was done subjectively by the Montreal Cognitive Assessment (MoCA) questionnaire and objectively by using EEG [absolute and relative power of alpha, beta, and theta waves along with theta/beta ratios (TBR) and theta/alpha ratio (TAR)] and P300 amplitude and latency of ERP during a visual oddball paradigm task in control (n = 30) and PCOS (n = 37) subjects. Results: PCOS women showed significantly higher anxiety and depression scores along with low MoCA scores. Significantly reduced absolute alpha, increased frontal beta, and markedly increased theta (relative) power with increased TAR in the PCOS group were seen. Also, a significant reduction in P300 amplitude with prolonged latency during the visual oddball paradigm task was evident in them. Conclusion: Reduced alpha and higher theta activity with increased TAR are indicative of poor neural processing ability. Reduced P300 amplitude with more latency also suggests a cognitive decline, which is corroborated by reduced MoCA scores. Our study objectively indicates the presence of subclinical cognitive impairment in PCOS patients even without any comorbidities.

Assessment of nerve conduction in evaluation of radiculopathy among chronic low back pain patients without clinical neurodeficit.

The diagnostic evaluation of chronic low back pain (CLBP) is difficult, as its primary causes are multiple. Clinical, radiological and electrophysiological findings are of limited value in diagnosing radiculopathy as the cause of CLBP in early cases. Current study was undertaken on 50 controls and 50 CLBP patients without clinical neurological deficit to evaluate the potential of nerve conduction studies, particularly H-reflex study for diagnosis of radiculopathy in these cases. We observed that routine nerve conductions in CLBP without clinical neurodeficit showed no significant differences; whereas all the H-reflex parameters, H-threshold, H latency, H amplitude and H/M ratio were significantly different when compared with that of control (P value < 0.0001 in each case). We concluded that subclinical cases might not have only partial conduction block but also secondary axonal loss due to compression of nerve roots. We further suggest inclusion of Soleus H-reflex study in evaluation of radiculopathy among early CLBP cases without clinical neurodeficit.

Impact of Altered Breathing Patterns on Interaction of EEG and Heart Rate Variability.

BACKGROUND: Altered pattern of respiration has been shown to affect both the cardiac as well as cortical activity, which is the basis of central-autonomic dual interaction concept. On the other hand, effect of this association between altered breathing with slow cortical activity, that is, electroencephalography (EEG) theta waves (associated with learning and relaxed alertness) on the cardiac autonomic balance is largely unclear. OBJECTIVE: The study aims to understand this interaction in response to altered respiratory patterns, for example, voluntary apnea, bradypnea, and tachypnea in terms of EEG and heart rate variability (HRV) correlates in normal healthy subjects. METHODS: This study was conducted on 32 adult male subjects. EEG from F3, F4, P3, P4, O1 and O2 cortical areas and Lead II electrocardiography for HRV analysis was continuously recorded during aforesaid respiratory interventions. Power spectral analysis of EEG for theta waves and HRV measures, that is, RMSSD, pNN50, HF, LF, and LF/HF was calculated as % change taking resting value as 100%. RESULTS: Apnea caused decrease in theta power, whereas an increase in LF/HF was observed in HRV. Bradypnea on the other hand, did not elicit any significant change in power of theta waves. However, decreased RMSSD and pNN50 were observed in HRV. Tachypnea led to increase in theta power with HRV depicting significantly decreased RMSSD and pNN50. Besides, significant correlation between EEG and HRV measures was found during tachypnea, which shifted toward posterior cortical sites as compared to resting condition. CONCLUSION: Various altered respiratory patterns caused either depressed parasympathetic or increased sympathetic output, whereas increased theta power along with posterior shift of correlation between theta power and HRV measures observed during post tachypnea might be due to involvement of global brain areas due to respiration-coupled neuronal activity. Thus, a definite link between cortical activity and autonomic output in relation to altered respiratory patterns may be suggested.

Neuro-Cognitive Profile of Morning and Evening Chronotypes at Different Times of Day.

BACKGROUND: Chronotype is the circadian time preference for sleep-wake timings. However, its impact on cognitive performance is least explored. OBJECTIVE: The present study investigated the effect of chronotype (morning "M" vs. evening "E") on cognitive measures as a function of time of the day. In addition, the correlation between electroencephalogram (EEG) waves and subjective/objective cognitive measures were investigated. METHOD: Cognitive status of 28 adult male subjects (15 "M" and 13 "E") was assessed objectively through event-related potential (ERP) by administering visual odd ball paradigm test and subjectively through Montreal Cognitive Assessment questionnaire. In addition, 20 to 30 min of resting EEG was recorded. Recordings were done from 8 to 10 am and from 4 to 6 pm on a single day. Power spectral analysis of EEG for alpha and beta waves at PZ and FZ cortical sites was done after subjecting selected epochs to fast Fourier transformation. Also, latency and amplitude of P300 potential from event-related potential record were measured. Appropriate statistical tests were applied for analysis. RESULTS: Higher alpha and beta power was observed in "E" at PZ in the evening. "M" showed increased P300 latency and amplitude during evening session for frequent and rare stimuli and vice versa in "E."' Significant negative correlation was seen between latency of rare stimuli and alpha and beta power at FZ site during evening in "E" chronotype only. CONCLUSION: Result indicates better attention and alertness during evening hours in evening chronotypes and vice versa in morning chronotypes. The findings could be implemented to schedule the mental performance/cognitive load according to individual chronotype.