Short Latency Research Articles

Short latency afferent inhibition: comparison between threshold-tracking and conventional amplitude recording methods.

Short-latency afferent inhibition (SAI), which is conventionally measured as a reduction in motor evoked potential amplitude (A-SAI), is of clinical interest as a potential biomarker for cognitive impairment. Since threshold-tracking has some advantages for clinical studies of short-interval cortical inhibition, we have compared A-SAI with a threshold-tracking alternative method (T-SAI). In the T-SAI method, inhibition was calculated by tracking the required TMS intensity for the targeted MEP amplitude (200 uV) both for the test (TMS only) and paired (TMS and peripheral stimulation) stimuli. A-SAI and T-SAI were recorded from 31 healthy subjects using ten stimuli at each of 12 inter-stimulus intervals, once in the morning and again in the afternoon. There were no differences between morning and afternoon recordings. When A-SAI was normalized by log conversion it was closely related to T-SAI. Between subjects, variability was similar for the two techniques, but within-subject variability was significantly smaller for normalized A-SAI. Conventional amplitude measurements appear more sensitive for detecting changes within-subjects, such as in interventional studies, but threshold-tracking may be as sensitive as detecting abnormal SAI in a patient.

Effectiveness of galvanic vestibular evoked myogenic potential for evaluation of Meniere’s disease

ObjectivesAlthough the cause of Meniere’s disease (MD) is not fully understood, endolymphatic hydrops is widely believed to be responsible for MD. Previous studies have used Air-Conducted Sound (ACS)-induced Vestibular Evoked Myogenic Potentials (VEMPs) to evaluate otolithic function in patients with MD. However, the use of Galvanic Vestibular Stimulation-VEMPs (GVS-VEMPs) with other vestibular tests in MD has been rare. This study aimed to explore the application of galvanic VEMPs in assessing MD. MethodsNormal individuals and patients with unilateral definite MD were included in this retrospective study. All participants underwent pure tone audiometry. Ocular and cervical VEMPs induced by GVS, and ACS were recorded. The characteristic parameters of VEMPs (n1 latency, p1 latency, amplitude, and AR) were analyzed. ResultsThe provocation rates of GVS-VEMPs did not differ between MD patients and control individuals. Compared with ACS, GVS could evoke potentials with longer latencies. MD patients presented GVS-VEMPs with lower amplitudes and ACS-cVEMP with shorter latencies and had a higher response rate in GVS-oVEMP. However, no differences or correlations were found in the characteristic parameters of GVS-VEMPs among the different stages of MD. ConclusionsGVS is as effective as ACS for inducing VEMP, and GVS-VEMP recording can detect retrolabyrinthine degeneration in MD. Further research is needed to assess the utility of GVS-VEMP in the evaluation of MD severity. Level of evidenceLevel 4.

Conditioned up and down modulations of short latency gamma band oscillations in visual cortex during fear learning in humans

Over the course of evolution, the human brain has been shaped to prioritize cues that signal potential danger. Thereby, the brain does not only favor species-specific prepared stimulus sets such as snakes or spiders but can learn associations between new cues and aversive outcomes. One important mechanism to achieve this is associated with learning induced plasticity changes in sensory cortex that optimizes the representation of motivationally relevant sensory stimuli. Animal studies have shown that the modulation of gamma band oscillations predicts plasticity changes in sensory cortices by shifting neurons’ responses to fear relevant features as acquired by Pavlovian fear conditioning. Here, we report conditioned gamma band modulations in humans during fear conditioning of orthogonally oriented sine gratings representing fear relevant and irrelevant conditioned cues. Thereby, pairing of a sine grating with an aversive loud noise not only increased short latency (during the first 180 ms) evoked visual gamma band responses, but was also accompanied by strong gamma power reductions for the fear irrelevant control grating. The current findings will be discussed in the light of recent neurobiological models of plasticity changes in sensory cortices and classic learning models such as the Rescorla–Wagner framework.

The effect of unexpected rewards on decision making in cuttlefish

Despite numerous studies demonstrating the cognitive ability of cephalopods, there is currently no study showing an emotion-like behavior in this group of animals. To examine whether cuttlefish have different internal states, we developed a behavioral paradigm to assess if prior surprised events are able to alter the choice made by cuttlefish. By presenting unexpected food rewards to cuttlefish before the test, we investigated whether the reaction time of choosing between two shrimps, an intuitive response toward the prey without previous learning, at three different levels of discriminative tests (easy, difficult, and ambiguous), are different compared to the one without an unexpected reward. This behavioral paradigm serves to demonstrate whether cuttlefish are aware of ambiguous situations, and their choice outcome and reaction time are dependent of their internal states. The results show that the response latency was significantly shortened in the difficult and ambiguous tests when choosing from two shrimps that are either moderately different in size or similar sizes, respectively, when cuttlefish have received unexpected rewards before the test. These results were compared with tests during which the cuttlefish did not receive any reward in advance. Furthermore, this shortening of latency did not result in a difference in choice outcome during the difficult and ambiguous tests. Interestingly, even when cuttlefish have obtained the expected food rewards or simply made tentacular strike without prey capture each time before test, these prior experiences were sufficient to shorten the response latency in the difficult and ambiguous tests. However, different from the result of unexpected rewards, food consumption alone or prey capture failure did affect the choice outcome during the simple and difficult tests. Taken together, our findings suggest that pre-test treatments of unexpected and expected rewards or simply unsuccessful visual attack seem to induce cuttlefish to adopt different foraging behaviors. This context dependent decision making suggests that cuttlefish’s foraging strategies are influenced by the previously surprised event and their internal states. It also shows a speed-accuracy tradeoff in difficult and ambiguous situations when foraging for prey. This observation may lead to a future investigation of the presence of emotional state in cephalopods.

Leflunomide-induced liver injury: Differences in characteristics and outcomes in Indian and US registries.

Leflunomide, a disease-modifying anti-rheumatic drug, has been associated with elevations of serum aminotransferases. Herein, we describe the clinical, laboratory features and outcomes of 17 patients with leflunomide/teriflunomide hepatotoxicity from two large drug-induced liver injury (DILI) registries. Consecutive, adjudicated cases of leflunomide (n=16)-or teriflunomide (n=1)-related DILI from a single centre in Bangalore, India and the multicentre US Drug-Induced Liver Injury Network (DILIN) were reviewed. Nine (0.8%) of the 1070 Indian patients and 8 (0.5%) of the 1400 DILIN patients fulfilled the criteria for DILI because of leflunomide- or teriflunomide. 89% of the Indian cases were women and all were associated with severe cutaneous adverse reaction (SCAR) and a median drug latency of 49days, whereas 37.5% of the DILIN cases were female, none exhibited SCAR and the median drug latency was 166days. Hepatocellular injury (70%) was more common in women than men (92% vs. 20%) and was associated with younger mean age (41 vs. 59years), higher peak INR (2.3 vs. 1.2) and higher mortality (58% vs. 0%). Mortality was observed in six patients from India (2 of the three with myocarditis) and one received liver transplantation from the USA. Leflunomide-induced liver injury is predominantly hepatocellular. Leflunomide hepatotoxicity is more likely accompanied by SCAR, a short latency and a higher mortality in the Indian cohort, with a predominance of females, compared to US DILIN patients. The differences in skin involvement, immunoallergic features and outcomes among subjects from India vs. the USA suggest that genetic or environmental factors are important in the pathogenesis of liver injury.

A novel method for quantitative evaluation of motor evoked potential monitoring during cerebrovascular surgeries

Transcranial motor evoked potential (MEP) monitoring, intended to assess cerebral cortical ischemia, may produce false negative results when the stimulation inadvertently activates the deep, subcortical motor pathways. This study examined hand MEP onset latency as a potential means to differentiate superficial versus deep stimulus penetration in surgical patients monitored for cerebral ischemia.Intraoperative MEP data were prospectively collected from 40 patients treated for intracranial aneurysm or carotid stenosis. Onset latencies of hand MEP responses were measured over a range of stimulation intensities from both the contralateral and ipsilateral hand (crossover responses). At the threshold for superficial, cortical stimulation of the contralateral hand, the MEP latency was 26.9 ± 0.4 ms. MEP onset latencies measurements became shorter as stimulation intensities were increased. At the maximum intensity (when crossover response was usually generated), the contralateral hand MEP latency of 22.5 ± 0.3 ms was significantly shorter than at threshold stimulation (p < 0.001). Latency-stimulus intensity plots best fit a 3 parameter hyperbolic decay function (r2 = 0.85 ± 0.02) and revealed a narrow window of acceptable MEP stimuli to obtain superficial cortical activation. Our analysis refutes the utility of the crossover response in reliably gauging depth of activation. Additionally, we found that differentiation between long and short MEP onset latency times may serve as a dependable marker for depth of stimulation. Attention to hand MEP onset latency may reduce inadvertent stimulation of the deep corticospinal tract pathways and avoid false negative MEP recordings during cerebrovascular surgeries.

Short Latency Radiation Induced Osteosarcoma Detected on 18F-FDG PET/CT Scan in Solitary Plasmacytoma.

18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays a pivotal role in the staging, restaging, and surveillance of various bone tumors, including plasmacytomas and osteosarcomas. Solitary plasmacytomas most frequently occur in the bones and are primarily treated with either surgery or radiotherapy. Radiation-induced osteosarcomas (RIOS) usually develop after a median interval of 11 years between radiation and sarcoma presentation. However, these can rarely present with a short latent period of 4 years or even lesser. In such cases, whole-body imaging plays a vital role in the early detection and management of RIOS. Herein, we present the case of a 29-year-old female patient with solitary plasmacytoma undergoing a follow-up whole-body 18F-FDG PET/CT, which revealed metastatic RIOS after a short latent period.

Optimized Algebraic Algorithm for Ambiguity Resolution and DOA Computation in Baseline Interferometer

Background: Interferometer is the most preferred technique for high accuracy direction finding. For broadband direction finding (DF) applications, multiple antennas forming a number of baselines are used to achieve better accuracy in measuring the direction of arrival (DOA). Ambiguity resolution in multi-element interferometers is a crucial algorithm for the computation of DOA. Objective: This paper introduces a fast, algebraic Common Minimum Modulo Search (CMMS) algo-rithm for ambiguity resolution and DOA computation. LabVIEW-based tool for Monte Carlo simula-tion of the algorithm over various parameters is described. Method: The CMMS is a computationally efficient algorithm, where the longest baseline phase difference is used for accuracy, and the phase difference data from all other baselines are used for resolving the ambiguities in the longest baseline. A hybrid approach using correlation and minimum algebraic search is used to determine the best fit set of ambiguities to the measured phase difference data. Results: Case studies have been presented in the literature and the performance of the CMMS algo-rithm was validated against established algorithms. This paper discusses the FPGA implementation as well as its simulation results. Analysis is performed on the 6-18 GHz frequency band. Moreover, the sources of errors and resulting limitations regarding the applicability of the algorithm are also discussed. Conclusion: Simulation results establish the algorithm's effectiveness in ambiguity resolution and applicability to diverse array configurations. The short nine-clock cycle processing latency in FPGA is demonstrated by the simulation results.

Pneumopathie atypique chez un soudeur : sidérose pulmonaire ?

Pulmonary siderosis or welder's lung is an occupational lung disease that is usually observed after chronic exposure to iron dust. A 55-years-old welder visited hospital with dyspnea linked to occupational exposure. Pulmonary function studies revealed lung function abnormalities with decerase of FEV1 and TPC. Based on the chest Tomography CT results, he was diagnosed with obliterans bronchiolitis. A chest biopsy was performed and the specimen is for a pulmonary siderosis aspect. This case of pulmonary siderosis is an unusual one by symptoms, CT images and short latency of exposure. An intense inhalation of iron particles could explain this case and inflammatory process and it highlights need of histological analysis of chest biopsy.

"Heart in DRESS": Cardiac Manifestations, Treatment and Outcome of Patients with Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome: A Systematic Review.

Cardiac involvement in drug reaction with eosinophilia and systemic symptoms (DS) is rare but associated with high mortality. The aim of this research was to systematically review case reports by PRISMA guidelines in order to synthetize the knowledge of cardiac manifestations of DS. We identified 42 cases from 36 case reports. Women were two times more affected than men. Two-thirds of patients had cardiac manifestation in the initial phase of the disease, while in one-third of cases cardiac manifestations developed later (mean time of 70 ± 63 days). The most common inciting medications were minocycline (19%) and allopurinol (12%). In 17% of patients, the heart was the only internal organ affected, while the majority (83%) had at least one additional organ involved, most commonly the liver and the kidneys. Dyspnea (55%), cardiogenic shock (43%), chest pain (38%), and tachycardia (33%) were the most common cardiac signs and symptoms reported. Patients frequently had an abnormal ECG (71.4%), and a decrease in left ventricular ejection fraction was the most common echocardiographic finding (45%). Endomyocardial biopsy or histological examination at autopsy was performed in 52.4%, with the predominant finding being fulminant eosinophilic myocarditis with acute necrosis in 70% of those biopsied. All patients received immunosuppressive therapy with intravenous steroids, while non-responders were more likely to have received IVIG, cyclosporine, mycophenolate, and other steroid-sparing agents (60%). Gender and degree of left ventricular systolic dysfunction were not associated with outcomes, but short latency between drug exposure and the first DRESS symptom onset (<15 days) and older age (above 65 years) was associated with death. This underscores the potential importance of heightened awareness and early treatment.

Kin recognition by cannibals is modulated by hunger level in a generalist predatory mite Amblyseius herbicolus (Chant) (Acari: Phytoseiidae)

AbstractCannibalism is a commonly found behaviour in the animal kingdom. The biggest concern of cannibalism is that it reduces the inclusive fitness of the cannibals by eliminating close relatives. Kin recognition is a strategy used by many cannibals to benefit from cannibalism without the cost of reducing their inclusive fitness by eating close relatives. Most members of the family Phytoseiidae are cannibalistic. Previous studies suggest that specialist phytoseiids practice kin recognition, while generalists use species recognition or discrimination due to the diet specification and frequent intraspecific interactions. We examined whether kin recognition is used by a type‐III generalist phytoseiid, Amblyseius herbicolus (Chant) (Acari: Phytoseiidae). The cannibalistic adults with different hunger levels (0‐, 24‐ and 48‐hr starvation) were given a choice of kin and a non‐kin larva. Kin recognition of A. herbicolus was affected by the hunger level. Adults not starved before the test significantly preferred cannibalizing non‐kin larva. Conversely, adults starved for 24 and 48 hr showed no statistically significant preference between kin and non‐kin larvae. Furthermore, the latency reflected hunger level, where not starved adults had the most prolonged latency, while adults starved for 24 and 48 hr had intermediate and shortest latency. This study suggests A. herbicolus use innate recognition mechanisms to avoid kin cannibalism since the adults and larvae had no prior association before the experiment. The effect of familiarization on kin recognition in A. herbicolus should be further investigated.

Active Middle Ear Implant Evoked Auditory Brainstem Response Intensity-Latency Characteristics.

ObjectiveTo analyze intensity-latency functions of intraoperative auditory evoked brainstem responses (ABRs) to stimulation by the Vibrant Soundbridge (VSB) active middle ear implant with respect to coupling efficiency, VSB evoked ABR thresholds, and coupling modality [oval window (OW) placement vs. Incus placement and vs. round window (RW) placement].Study DesignExploratory study.SettingBi-centric study at tertiary referral centers.PatientsTwenty-four patients (10 female, 14 male, mean age: 58 years) who received a VSB.Outcome MeasuresWave-V intensity-latency functions of intraoperative VSB evoked ABRs using a modified audio processor programmed to preoperative bone conduction thresholds for stimulation. Threshold level correction to coupling efficiency and ABR thresholds. Individual plots and exponential function fits.ResultsAfter ABR threshold level correction, the latency functions could be aligned. A large variance of latencies was observed at individual threshold level. Wave-V latency was longest in the Incus placement subgroup (9.73 ms, SD: 1.04) as compared to OW placement subgroup (9.47 ms, SD: 1.05), with the shortest latency in the RW placement subgroup (8.99 ms, SD: 0.68). For increasing stimulation levels, the variance decreased with intensity-latency function slopes converging toward a steady-state (saturation) latency caused by saturation of audio processor (stimulation) gain. Latency saturation was reached at a stimulation level of 50 dB nHL for the OW placement subgroup, 35 dB nHL for the Incus placement subgroup, and 30 dB nHL for the RW placement subgroup. The latency and saturation results indicated decreased dynamic range for RW placement, i.e., reverse stimulation.ConclusionsVSB evoked ABR wave-V intensity-latency function slopes were similar to acoustic stimulation at high stimulation levels with a shift toward longer latencies caused by audio processor signal delay. Saturation of latencies occurred for higher stimulation levels due to saturation of audio processor gain. Thus, the analysis of VSB evoked intensity-latency functions appears to allow for the objective assessment of a patient's individual dynamic range. This can further improve diagnostics as well as intraoperative and postoperative quality control.

Kinetics of the Antibody Response to Boostering With Three Different Vaccines Against SARS-CoV-2

BackgroundHeterologous vaccinations against SARS-CoV-2 with ChAdOx1 nCoV-19 and a second dose of an mRNA-based vaccine have been shown to be more immunogenic than homologous ChAdOx1 nCoV-19. In the current study, we examined the kinetics of the antibody response to the second dose of three different vaccination regimens (homologous ChAdOx1 nCoV-19 vs. ChAdOx1 nCoV-19 + BNT162b2 or mRNA-1273) against SARS-CoV-2 in a longitudinal manner; whether there are differences in latency or amplitude of the early response and which markers are most suitable to detect these responses.MethodsWe performed assays for anti-S1 IgG and IgA, anti-NCP IgG and a surrogate neutralization assay on serum samples collected from 57 participants on the day of the second vaccination as well as the following seven days.ResultsAll examined vaccination regimens induced detectable antibody responses within the examined time frame. Both heterologous regimens induced responses earlier and with a higher amplitude than homologous ChAdOx1 nCoV-19. Between the heterologous regimens, amplitudes were somewhat higher for ChAdOx1 nCoV-19 + mRNA-1273. There was no difference in latency between the IgG and IgA responses. Increases in the surrogate neutralization assay were the first changes to be detectable for all regimens and the only significant change seen for homologous ChAdOx1 nCoV-19.DiscussionBoth examined heterologous vaccination regimens are superior in immunogenicity, including the latency of the response, to homologous ChAdOx1 nCoV-19. While the IgA response has a shorter latency than the IgG response after the first dose, no such difference was found after the second dose, implying that both responses are driven by separate plasma cell populations. Early and steep increases in surrogate neutralization levels suggest that this might be a more sensitive marker for antibody responses after vaccination against SARS-CoV-2 than absolute levels of anti-S1 IgG.

Estimating the integrated degradation rates of woody debris at the scale of a Mediterranean coastal catchment

Woody debris is found in all habitats of the land-sea continuum. While isolated experimental studies of wood degradation exist, few programs have observed the dynamics of wood degradation, in situ across this gradient. Since 2014, we have been conducting a series of long-term observations of wood decay in three characteristic areas of a Mediterranean Sea coastal watershed: forest leaf litter (‘Forest’), river bed (‘River’) and the near-shore marine environment (‘Sea’). The study sites are within the Massane River watershed (France) whose headwaters are in a protected beech tree (Fagus sylvatica) dominated forest. Branch sections from a recently fallen beech tree and standardized blocks of Norway spruce (Picea abies) were installed in all three environments. The proportion of remaining mass and volumetric mass of the individual wood samples were determined periodically over 4.2 years. Regardless of wood type, there were marked differences in the decay dynamics. Mass losses at the Forest and River sites were well-described by continuous negative exponential models. At the Sea site, there was a short latency period followed by rapid degradation for the wood fraction exploited by shipworms; in this case, a Weibull-type function was fitted to the data. Integrated mass loss rates at the coastal location were 6 to 20 times faster than in the other two environments. Our study suggests that the early dynamics of wood degradation in a land-sea meta-ecosystem are dominated by the marine invertebrate community. This means woody debris, once it reaches the sea, is likely to break down rapidly within near shore coastal habitats. These results highlight the need to quantify the mass transport dynamics between local ecosystems.

Demand MemCpy: Overlapping of Computation and Data Transfer for Heterogeneous Computing

Heterogeneous computing relies on collaboration among different types of processors on shared data. In systems with discrete accelerators (e.g., GP-GPU), data sharing requires transferring a large amount of data between CPU and accelerator memories and can significantly increase the end-to-end execution time. This paper proposes a novel mechanism called <i>Demand MemCpy</i> (<i>DMC</i>) to hide the data sharing overheads. DMC copies data from host memory to accelerator memory based on demands at page granularity. It utilizes a hardware-only mechanism to fetch the requested page with a short latency and the background pre-copy to fetch related pages in advance. Our evaluation shows that DMC can reduce the end-to-end execution time of GP-GPU application by 25.4% on average by overlapping computation with data transfer and not transferring unused pages.

Epileptic Seizure Detection Using Brain-Rhythmic Recurrence Biomarkers and ONASNet-Based Transfer Learning.

The electroencephalogram (EEG) tool has great potential for real-time monitoring of abnormal brain activities, such as preictal and ictal seizures. Developing an EEG-based detection system for patients with epilepsy is vital for clinical management and targeted therapy. This paper proposes a single-channel seizure detection system using brain-rhythmic recurrence biomarkers (BRRM) and an optimized model (ONASNet). BRRM is a direct mapping of the recurrence morphology of brain rhythms in phase space; it reflects the nonlinear dynamics of original EEG signals. The architecture of ONASNet is determined through a modified neural network searching strategy. Then, we exploited transfer learning to apply ONASNet to our EEG data. The combination of BRRM and ONASNet leverages the multiple channels of a neural network to extract features from different brain rhythms simultaneously. We evaluated the efficiency of BRRM-ONASNet on the real EEG recordings derived from Bonn University. In the experiments, different transfer-learning models (TLMs) are respectively constructed using ONASNet and seven well-known neural network structures (VGG16/VGG19/ResNet50/InceptionV3/DenseNet121/Xception/NASNet). Moreover, we compared those TLMs by model size, computing complexity, learning capability, and prediction latency. ONASNet outperforms other structures by strong learning capability, high stability, small model size, short latency, and less requirement of computing resources. Comparing BRRM-ONASNet with other existing methods, our work performs better than others with 100% accuracy under the identical dataset and same detection task. Contributions: The proposed method in this study, analyzing nonlinear features from phase-space representations using a deep neural network, provides new insights for EEG decoding. The successful application of this method in epileptic-seizure detection contributes to computationally medical assistance for epilepsy.

New Hybrid IoT LoRaWAN/IRC Sensors: SMART Water Metering System

The massive development of internet of things (IoT) technologies is gaining momentum across all areas of their possible deployment—spanning from Industry 4.0 to eHealth, smart city, agriculture or waste management. This ongoing development is further pushed forward by the gradual deployment of 5G networks. With 5G capable smart devices, it will be possible to transfer more data with shorter latency thereby resulting in exciting new use cases such as Massive IoT. Massive-IoT (low-power wide area network-LPWAN) enables improved network coverage, long device operational lifetime and a high density of connections. Despite all the advantages of massive-IoT technology, there are certain cases where the original concept cannot be used. Among them are dangerous explosive environments or issues caused by subsurface deployment (operation during winter months or dense greenery). This article presents the concept of a hybrid solution of IoT LoRaWAN (long range wide area network)/IRC-VLC (infrared communication, visible light communication) technology, which combines advantages of both technologies according to the deployment scenario.

Benzocaine and Eugenol as anesthetics for pangasius juveniles, Pangasianodon hypophthalmus

The aim of this study was to evaluate the effect and efficacy of different concentrations of eugenol and benzocaine for pangasius juveniles (Pangasianodon hypophthalmus) and determine the anesthetic and concentration most appropriate for carrying out routine fish farming practices for this species. Onehundred juveniles with an average weight of 32.10 ± 4.9 g and an average total length of 15.32 ± 0.57 cm were used. Four concentrations of both anesthetics were evaluated: 0, 25, 50, 75 and 100 mg/L, with four induction time stages and three recovery stages. During the time that the fish remained anesthetized, biometric procedures were performed. Then, they were transferred to a 10-liter aquarium containing clean water, without adding the anesthetic to observe the recovery time. After recovery, the animals were kept in aquariums for 72 hours to check for mortality. Eugenol, at all concentrations evaluated, and benzocaine, at a concentration of 25 mg/L, were not effective in sedating juveniles of pangasius. Benzocaine concentrations of 75 and 100 mg/L were effective for anesthesia and recovery of fish within the time span of five andseven minutes. However, considering animal welfare, the use of a concentration of 100 mg/L is recommended, as it resulted in shorter latency and recovery times.

Effect of Maternal Age and Anaemia on Auditory Brainstem Response of Preterm Infants in a Tertiary Care Hospital of Kolkata, West Bengal: A Cross-sectional Study

Introduction: Adolescent pregnancy and maternal anaemia have a detrimental effect on infant growth and development. They are associated with greater risk of premature births and Low Birth Weight (LBW). Wave Interpeak Latencies (IPLs) of infant Auditory Brainstem Response (ABR) indicate the degree of maturation of brainstem auditory pathways among preterm infants. Previous studies indicated that preterm infants show prolonged wave Interpeak Latencies (IPLs). Whether maternal parameters like age and haemoglobin level contributes to the changes in infant ABR is debated. Aim: To study the effect of maternal age and anaemic status on Brainstem Evoked Response Audiometry (BERA) changes among preterm infants. Materials and Methods: An observational, descriptive study of cross-sectional design was undertaken in the Neurophysiology laboratory of Department of Physiology, RG Kar Medical College and Hospital, Kolkata from December 2019 to December 2022. Total of 119 mother-preterm infant dyads were included. Click BERA was performed on the babies aged between 3 months to 1 year. Absolute and IPLs of wave I,III and V were obtained. Mothers were assigned anaemic status {Haempglobin (Hb) level&lt;9gm/dL} based on the information in their antenatal card. Student’s t test, Fisher’s exact test, one way ANOVA test were used for data analysis. A p-value less than 0.05 was considered significant. Results: Out of 76 adolescent mothers (age between 10 to &lt;18 years), 43 (56.6%) were anaemic. Out of 43 adult mothers (with age ≥18 years), 33 (76.7%) were anaemic. Mothers were divided into four groups, namely adolescent anaemic (n=43) and adolescent non anaemic (n=33), adult anaemic (n=33) and adult non anaemic (n=10). Distribution of data with respect to education years, social class and occupation among four mothers’ group was comparable [p-value&gt;0.05]. Preterm infants born to both anaemic adult [Hedges g=2.51] and anaemic adolescent mothers [Hedges g=1.06] showed dyssynchronous shortening of wave latencies compared to non anaemic counterparts (p-value&lt;0.05). Magnitude of difference with respect to infant ABR for non anaemic adolescent mothers vs non anaemic adult counterparts was large [Hedge s g=1.05] with p-value&lt;0.05. While maternal anaemia showed either shortening or prolongation of IPLs, adolescent maternal age was related with prolongation of the wave I-V. Effect size of maternal anaemia on infant ABR was more than for adolescent maternal age. Conclusion: Maternal anaemia may exaggerate abnormal maturation of the brain stem pathways in preterm infants irrespective of maternal age.

SSPE in Children Younger than 3 Years

Subacute sclerosing panencephalitis (SSPE) is typically observed in school-going children, adolescents, and young adults. Herein, we report a 3-year-old boy of SSPE and systematically review all such reported cases (age ≤3 years). We searched PubMed database on June 16, 2020 with “English language &amp; Human only” restrictions. Eligible publications were screened and retrieved by three authors (NK, SP, and RU). Variables like author, year of publication, country, age of onset, sex, duration of illness, immunization, history of measles, clinical presentation, neuroimaging, treatment, and outcome were extracted. Neurological outcome was assessed in terms of improvement, static course or death. The defined search criteria resulted in 791 manuscripts (1951 to June 16, 2020). Only 47 manuscripts were eligible for data extraction. Seventy cases were retrieved. The mean age of onset was 26.34 months. The M:F ratio was 3.2:1. Turkey (19 cases), India (10 cases), and Japan (10 cases) collectively comprised more than half cases of SSPE. Only six children were immunized, 17 have no measles immunization, and the rest 47 had insufficient immunization records. Preceding history of measles was present in 27 cases. Most patients presented in stage II/III with altered sensorium, myoclonic jerks, and seizures. The most common reported outcome was death (18/70) followed by vegetative state (10/70). The absence of measles vaccination is frequently associated with childhood SSPE. Early measles vaccination may prevent SSPE in toddlers. Perinatal measles infection results in short onset latency and fulminant course. Outcome was not good in reviewed age group of ≤3 years.