A Cross-Sectional Study on Fall Direction and Lower Limb Loading in Response to a Perturbation on Laterally Inclined Platform.

Perturbation-based balance training (PBT) improves reactive stepping in older adults and people with neurological disorders. Slip-induced falls are a threat to older adults, leading to hip fractures. Fall-prone individuals must be trained to regain balance during a fall in the posterolateral direction. This study aims to analyze the characteristics of the reactive step induced by a laterally inclined platform. This cross-sectional study included 46 healthy participants who performed a "lean and release" backward fall using a platform with two inclined angles on each side. Kinovea software was used to analyze the step width. Reactive steps, characterized by crossover or medial foot placement, are preventive measures against posterolateral falls. The first objective was on the narrowed step width that was subjected to analysis using analysis of variance (ANOVA) and Tukey's post hoc assessment, indicating a tendency toward posterolateral falls. As part of our second objective, the inclined platform resulted in uneven loading between the legs, with a preference for the unloaded leg as the reactive leg (p < 0.001), as determined by Fisher's exact test and Cramer's V. These characteristics align closely with those observed in modified constraint-induced movement therapy (mCIMT). The angled platform had a significant effect on selecting the reactive leg, particularly at higher angles (p < 0.001). Thus, the study suggested that the device is capable of inducing posterolateral falls and exhibited mCIMT characteristics.

Behavioral paradigm for the evaluation of stimulation-evoked somatosensory perception thresholds in rats.

Intracortical microstimulation (ICMS) of the somatosensory cortex via penetrating microelectrode arrays (MEAs) can evoke cutaneous and proprioceptive sensations for restoration of perception in individuals with spinal cord injuries. However, ICMS current amplitudes needed to evoke these sensory percepts tend to change over time following implantation. Animal models have been used to investigate the mechanisms by which these changes occur and aid in the development of new engineering strategies to mitigate such changes. Non-human primates are commonly the animal of choice for investigating ICMS, but ethical concerns exist regarding their use. Rodents are a preferred animal model due to their availability, affordability, and ease of handling, but there are limited choices of behavioral tasks for investigating ICMS. In this study, we investigated the application of an innovative behavioral go/no-go paradigm capable of estimating ICMS-evoked sensory perception thresholds in freely moving rats. We divided animals into two groups, one receiving ICMS and a control group receiving auditory tones. Then, we trained the animals to nose-poke - a well-established behavioral task for rats - following either a suprathreshold ICMS current-controlled pulse train or frequency-controlled auditory tone. Animals received a sugar pellet reward when nose-poking correctly. When nose-poking incorrectly, animals received a mild air puff. After animals became proficient in this task, as defined by accuracy, precision, and other performance metrics, they continued to the next phase for perception threshold detection, where we varied the ICMS amplitude using a modified staircase method. Finally, we used non-linear regression to estimate perception thresholds. Results indicated that our behavioral protocol could estimate ICMS perception thresholds based on ~95% accuracy of rat nose-poke responses to the conditioned stimulus. This behavioral paradigm provides a robust methodology for evaluating stimulation-evoked somatosensory percepts in rats comparable to the evaluation of auditory percepts. In future studies, this validated methodology can be used to study the performance of novel MEA device technologies on ICMS-evoked perception threshold stability using freely moving rats or to investigate information processing principles in neural circuits related to sensory perception discrimination.

Behavioral Paradigm for the Evaluation of Stimulation-Evoked Somatosensory Perception Thresholds in Rats.

Intracortical microstimulation (ICMS) of the somatosensory cortex via penetrating microelectrode arrays (MEAs) can evoke cutaneous and proprioceptive sensations for restoration of perception in individuals with spinal cord injuries. However, ICMS current amplitudes needed to evoke these sensory percepts tend to change over time following implantation. Animal models have been used to investigate the mechanisms by which these changes occur and aid in the development of new engineering strategies to mitigate such changes. Non-human primates are commonly the animal of choice for investigating ICMS, but ethical concerns exist regarding their use. Rodents are a preferred animal model due to their availability, affordability, and ease of handling, but there are limited choices of behavioral tasks for investigating ICMS. In this study, we investigated the application of an innovative behavioral go/no-go paradigm capable of estimating ICMS-evoked sensory perception thresholds in freely moving rats. We divided animals into two groups, one receiving ICMS and a control group receiving auditory tones. Then, we trained the animals to nose-poke - a well-established behavioral task for rats - following either a suprathreshold ICMS current-controlled pulse train or frequency-controlled auditory tone. Animals received a sugar pellet reward when nose-poking correctly. When nose-poking incorrectly, animals received a mild air puff. After animals became proficient in this task, as defined by accuracy, precision, and other performance metrics, they continued to the next phase for perception threshold detection, where we varied the ICMS amplitude using a modified staircase method. Finally, we used non-linear regression to estimate perception thresholds. Results indicated that our behavioral protocol could estimate ICMS perception thresholds based on ∼95% accuracy of rat nose-poke responses to the conditioned stimulus. This behavioral paradigm provides a robust methodology for evaluating stimulation-evoked somatosensory percepts in rats comparable to the evaluation of auditory percepts. In future studies, this validated methodology can be used to study the performance of novel MEA device technologies on ICMS-evoked perception threshold stability using freely moving rats or to investigate information processing principles in neural circuits related to sensory perception discrimination.

Migration patterns of peripherally inserted central venous catheters at 24 hours postinsertion in neonates.

OBJECTIVE: Migration of peripherally inserted central venous catheters (PICCs) is known to happen in neonates with changes in position of the upper limb. The aim of this study is to document the migration pattern of PICCs at 24 hours postinsertion, while controlling for arm position. STUDY DESIGN: This was a single-centered prospective study of 100 consecutively placed PICCs in a level III neonatal intensive care unit (NICU). All PICCs were inserted by one of two certified NICU nurses in either upper or lower limb. An X-ray was obtained immediately after insertion and again at 24 hours postinsertion; both were reviewed by a single pediatric radiologist. RESULTS: Of the PICCs placed in basilic veins, 35.5% migrated toward the heart, 14.5% migrated away from the heart, and 50% did not change in position. Of the PICCs placed in cephalic veins, 21% migrated toward the heart, 15.7% migrated away from the heart, and 63.3% did not change in position. None of the PICCs placed in the saphenous veins migrated. CONCLUSION: After controlling for arm position, 47% of PICCs placed in the upper limb migrated at 24 hours postinsertion with 32.6% migrating toward the heart. We recommend a follow-up X-ray at 24 hours postinsertion for all catheters placed in the upper limb.

Natural history of fetal renal pyelectasis.

OBJECTIVE: To follow the natural progression of fetal renal pyelectasis detected in the mid second trimester ultrasound in an unselected obstetric population. STUDY DESIGN: Single-centered, retrospective study that included all level II ultrasounds done from Jan 2008 to Dec 2009. The initial level II ultrasound was done in the mid second trimester. The renal pyelectasis detected on the antenatal ultrasound (AUS) was classified as mild (5-7 mm), moderate (7.1-9 mm), or severe (>9.1 mm). Postnatal outcomes were classified as "Resolved", "Improving", or "Worsened". RESULTS: Ninety-eight cases of fetal renal pyelectasis were detected. Sixteen patients were excluded. Of the remaining 82 cases of fetal pyelectasis, 32 (39%) were mild, 21 (25.6%) moderate, and 29 (35.4%) severe. In 74 (90.2%) infants, pyelectasis resolved, remained stable, or improved in the postnatal ultrasound. In eight (9.8%) infants, pyelectasis worsened. CONCLUSION: Totally, 90.2% of pyelectasis detected on AUS resolved spontaneously, remained stable or improved. The magnitude of fetal renal pyelectasis did not correlate with postnatal outcome. All fetal renal pyelectasis ≥ 5 mm detected on the mid second trimester ultrasound should be followed antenatally. Those fetuses with persistent pyelectasis should be evaluated after birth and followed until resolution of pyelectasis or until a diagnosis is obtained.

Subgaleal abscess and E. coli septicemia following scalp electrode in a preterm newborn: a case report.

Escherichia coli as a causative agent for neonatal sepsis is well established. However, there is paucity of reports in the medical literature of E. coli sepsis following scalp electrode placement. We report a preterm infant who developed scalp abscess and E. coli sepsis following a scalp electrode. We recommend a careful examination of babies with a history of fetal electrode monitoring as this could be a nidus for local and generalised infection.