A surface electrode adjacent to vagal nerve stimulator lead can aid in characterizing vagal nerve stimulator-mediated pediatric sleep-disordered breathing: a case series of 7 patients.

STUDY OBJECTIVES: The vagal nerve stimulator (VNS) is a nonpharmacological treatment for refractory epilepsy. A side effect of the VNS is sleep-disordered breathing. The purpose of this study was to demonstrate how a surface electrode placed over the VNS lead can help distinguish whether sleep-disordered breathing is due to VNS discharge. METHODS: Seven pediatric patients (aged 7.7 ± 2.2 years) with a VNS underwent a polysomnogram with an additional surface electrode on the left anterolateral neck to detect VNS discharge. The VNS-associated apnea-hypopnea index was calculated by determining the number of hypopneas and apneas occurring during VNS discharge. We evaluated the veracity of the VNS electrode by comparing signal duration and total number to those expected by programmed settings. We compared these findings to chin electromyogram signal change. RESULTS: Three patients had an obstructive pattern with VNS discharge, and 3 had an increase in respiratory rate without gas exchange abnormalities, including 1 with both patterns; 1 patient experienced no respiratory abnormalities. The mean obstructive apnea-hypopnea index was 8.2 ± 8.3 events/h. The mean VNS-associated apnea-hypopnea index was 4.8 ± 6.2 events/h and accounted for 46.9 ± 30.2% of the total obstructive apnea-hypopnea index. The additional electrode captured a statistically high percentage of expected discharges (94.7 ± 6.5%) compared to chin electromyogram (36.1 ± 35.8%; P < .05). CONCLUSIONS: We demonstrated that a surface electrode on the VNS lead can temporally coregister VNS discharges and enabled us to attribute sleep-disordered breathing to VNS stimulation in 4 patients. We propose that this sensor be standard procedure in patients with VNS undergoing polysomnogram. CITATION: Chan JHM, DelRosso LM, Ruth C, Wrede JE. A surface electrode adjacent to vagal nerve stimulator lead can aid in characterizing vagal nerve stimulator-mediated pediatric sleep-disordered breathing: a case series of 7 patients. J Clin Sleep Med. 2022;18(8):1973-1981.

Determinants of ferritin response to oral iron supplementation in children with sleep movement disorders.

STUDY OBJECTIVES: To identify children who respond to oral iron supplementation as evidenced by increased ferritin levels and to identify factors that correlate with improvement in ferritin levels in those who respond. METHODS: A retrospective chart review of the PLMS/RLS/RSD database at Seattle Children's Hospital was carried out. Data collected included nocturnal polysomnography parameters, age, sex, initial and follow-up ferritin level and date of collection, and presence of restless legs syndrome (RLS), periodic limb movements of sleep (PLMS)/PLM disorder (PLMD), restless sleep disorder (RSD), obstructive sleep apnea (OSA), neurologic, psychiatric, neurodevelopmental, or medical comorbidity. Oral iron therapy was evaluated by side effects (none; constipation; bad taste/nausea), subjective outcome in symptoms (resolved, improved, no change), and adherence to therapy (poor, fair, good). RESULTS: Seventy-seven children were included in this study of whom 42 were classified as responders (increase in ferritin of ≥10 µg/L) and 35 were nonresponders. Age and sex were not different between groups. Adherence was the only significant predictor of an increase in ferritin of ≥10 µg/L. Constipation was seen in 7.1% of responders vs. 45.8% of nonresponders. No change in symptoms was reported in 26.2% of responders vs. 71.4% in nonresponders. A significant correlation was found between treatment duration and ferritin level change in responders but not in nonresponders. CONCLUSIONS: Side effects hinders adherence to oral iron supplementation in children. Responders to oral iron show improvement in ferritin levels and symptoms, while nonresponders show no improvement in ferritin levels despite a long-lasting treatment, at least in part of them.

Case of an In-Laboratory Vagal Nerve Stimulator Titration for Vagal Nerve Stimulator-Induced Pediatric Obstructive Sleep Apnea.

None: We present the case of a 12-year-old girl with medically refractory epilepsy and a vagal nerve stimulator (VNS), who experienced severe obstructive sleep apnea (OSA) with respiratory events closely matching her VNS settings. We demonstrated a real-time decrease in OSA through an in-laboratory VNS titration study, decreasing her VNS frequency from 20 Hz to 10 Hz. We were able to demonstrate a baseline level of OSA by turning off the VNS. We then effectively treated her residual OSA with continuous positive airway pressure (CPAP). Novel to our case is that this in-laboratory VNS titration did not result in any subsequent increase in seizure frequency. After 5 months, her seizure frequency had decreased. Our case demonstrates that in-laboratory VNS titration can be an efficient tool for optimizing treatment of VNS-induced OSA and assert that polysomnography before VNS placement is important for guiding future care.

Acetylcholine contributes to the integration of self-movement cues in head direction cells.

Acetylcholine contributes to accurate performance on some navigational tasks, but details of its contribution to the underlying brain signals are not fully understood. The medial septal area provides widespread cholinergic input to various brain regions, but selective damage to medial septal cholinergic neurons generally has little effect on landmark-based navigation, or the underlying neural representations of location and directional heading in visual environments. In contrast, the loss of medial septal cholinergic neurons disrupts navigation based on path integration, but no studies have tested whether these path integration deficits are associated with disrupted head direction (HD) cell activity. Therefore, we evaluated HD cell responses to visual cue rotations in a familiar arena, and during navigation between familiar and novel arenas, after muscarinic receptor blockade with systemic atropine. Atropine treatment reduced the peak firing rate of HD cells, but failed to significantly affect other HD cell firing properties. Atropine also failed to significantly disrupt the dominant landmark control of the HD signal, even though we used a procedure that challenged this landmark control. In contrast, atropine disrupted HD cell stability during navigation between familiar and novel arenas, where path integration normally maintains a consistent HD cell signal across arenas. These results suggest that acetylcholine contributes to path integration, in part, by facilitating the use of idiothetic cues to maintain a consistent representation of directional heading. (PsycINFO Database Record

WITHDRAWN: A Comparison of Internet Monitoring with Continuous Glucose Monitoring in Insulin-Requiring Type 2 Diabetes Mellitus.

OBJECTIVE: To compare the effects of real-time continuous glucose monitoring (RT-CGM) and an Internet blood glucose monitoring system (IBGMS) on glycated hemoglobin levels in patients with type 2 diabetes mellitus treated with insulin. METHODS: Fifty-seven patients with type 2 diabetes treated with insulin were assigned randomly to 1 of 2 groups. Group 1 had the results of their self-monitoring of blood glucose level monitored biweekly using an IBGMS. Group 2 used RT-CGM and were monitored biweekly. Both groups used a secure website to upload data and to receive feedback from their endocrinologist. A1C and laboratory test results were collected at 0, 3 and 6 months. RESULTS: The baseline parameters were not significantly different. After a 6-month follow-up period, both IBGMS and RT-CGM showed significant within-group improvements in A1C level. In the IBGMS group, the A1C level decreased from 8.79%±1.25% to 7.96%±1.30% (p<0.05). The RT-CGM group decreased from 8.80%±1.37% to 7.49%±0.70% (p<0.001). IBGMS and RT-CGM did not show significantly different A1C levels at baseline, 3 and 6 months (p>0.05). CONCLUSIONS: The use of both IBGMS and RT-CGM significantly improved A1C levels in patients with type 2 diabetes treated with insulin in a randomized trial over a 6-month period. There were no significant differences in A1C values between groups after 6 months.

The effectiveness of Internet intervention on 926 patients with diabetes mellitus for up to 30 months.

OBJECTIVE: To assess the long-term effect of an Internet blood glucose monitoring system (IBGMS) on patients with type 1 diabetes mellitus and patients with type 2 diabetes. METHODS: In all, 1200 patients were offered to be taught to communicate with their endocrinologists using standardized glucose level reports by e-mail, and received feedback within 24 hours. The first 926 patients enrolled were reviewed consecutively from March 2011 to October 2013. Seventy-seven of these patients were excluded owing to lack of glycated hemoglobin (A1C) data. The remaining 849 patients consisted of 295 patients with type 1 diabetes and 554 patients with type 2 diabetes. Nonreporters are patients with no record of reporting (n=167), whereas the reporters had reported at least once (n=682). The A1C values were obtained at registration; follow-up values at 3-month intervals were recommended. RESULTS: Reporter A1C decreased from 8.13%±1.34% to 7.74%±1.11% (p<0.0001). Reporters with type 1 diabetes dropped from 8.04%±1.23% to 7.72%±1.03% (n=238; p<0.0001). Reporters with type 2 diabetes dropped from 8.18%±1.40% to 7.75%±1.14% (n=444; p<0.0001) and were subdivided based on treatment: those on oral hypoglycemic agents declined from 7.96%±1.38% to 7.49%%±1.03% (p<0.0001), and those on insulin with or without oral hypoglycemic agents declined from 8.40%%±1.39% to 8.02%±1.20% (p<0.0001). The nonreporters did not show a significant change in A1C. CONCLUSIONS: Initial and prolonged improvement was found in A1C levels for all reporters. The data support that numerous patients can be followed up effectively using the Internet for as long as 30 months.

Real-time continuous glucose monitoring versus internet-based blood glucose monitoring in adults with type 2 diabetes: a study of treatment satisfaction.

AIMS: To compare treatment satisfaction between real-time continuous glucose monitoring (RT-CGM) and internet-blood glucose monitoring (IBGM) in adults with type 2 diabetes treated with insulin. METHODS: This study recruited 40 patients who completed a parallel randomized controlled trial comparing a RT-CGM to an IBGM. Patients in the RT-CGM group monitored their blood-glucose levels bi-weekly and emailed results to their endocrinologist. Patients in the IBGM group also monitored their blood-glucose levels bi-weekly, but entered their data into an IBGM. Both groups used a secure website to submit blood-glucose readings and to receive feedback from their endocrinologist. Feedback included changes in therapy, suggestions on testing frequency, lifestyle modifications and/or encouragement to continue with no changes. At the end of 6 months, treatment satisfaction was measured using the 8-item Diabetes Treatment Satisfaction Questionnaire. In this study, "treatment" refers to the blood glucose monitoring system to which patients were randomized. RESULTS: Thirty-two of the 40 patients completed the treatment satisfaction questionnaire (80%). Compared to the RT-CGM group, the IBGM group reported a significantly higher level of overall treatment satisfaction (24.80 vs. 33.41, p<0.000). Ratings of individual satisfaction components including convenience, flexibility, likelihood of recommending treatment to others, and willingness to continue with treatment were also found to be significantly higher in the IBGM group. CONCLUSION: Patients using IBGM are more satisfied with their blood glucose monitoring system compared to those using RT-CGM.

Interictal neurocognitive processing of visual stimuli in migraine: evidence from event-related potentials.

Research has established decreased sensory habituation as a defining feature in migraine, while decreased cognitive habituation has only been found with regard to cognitive assessment of the relative probability of the occurrence of a stimulus event. Our study extended the investigation of interictal habituation in migraine to include cognitive processing when viewing of a series of visually-complex images, similar to those we encounter on the internet everyday. We examined interictal neurocognitive function in migraine from a habituation perspective, using a novel paradigm designed to assess how the response to a series of images changes over time. Two groups of participants--migraineurs (N = 25) and non-migraine controls (N = 25)--were asked to view a set of 232 unfamiliar logos in the context of a target identification task as their brain electrical responses were recorded via event-related potentials (ERPs). The set of logos was viewed serially in each of 10 separate trial blocks, with data analysis focusing on how the ERP responses to the logos in frontal electrodes from 200-600 ms changed across time within each group. For the controls, we found that the amplitude of the late positive potential (LPP) ERP component elicited by the logos had no significant change across trial blocks. In contrast, in migraineurs we found that the LPP significantly increased in amplitude across trial blocks, an effect consistent with a lack of habituation to visual stimuli seen in previous research. Our findings provide empirical support abnormal cognitive processing of complex visual images across time in migraineurs that goes beyond the sensory-level habituation found in previous research.

A comparison of internet monitoring with continuous glucose monitoring in insulin-requiring type 2 diabetes mellitus.

OBJECTIVE: To compare the effects of real-time continuous glucose monitoring (RT-CGM) and an Internet blood glucose monitoring system (IBGMS) on glycated hemoglobin levels in patients with type 2 diabetes mellitus treated with insulin. METHODS: Fifty-seven patients with type 2 diabetes treated with insulin were assigned randomly to 1 of 2 groups. Group 1 had the results of their self-monitoring of blood glucose level monitored biweekly using an IBGMS. Group 2 used RT-CGM and were monitored biweekly. Both groups used a secure website to upload data and to receive feedback from their endocrinologist. A1C and laboratory test results were collected at 0, 3 and 6 months. RESULTS: The baseline parameters were not significantly different. After a 6-month follow-up period, both IBGMS and RT-CGM showed significant within-group improvements in A1C level. In the IBGMS group, the A1C level decreased from 8.79%±1.25% to 7.96%±1.30% (p<0.05). The RT-CGM group decreased from 8.80%±1.37% to 7.49%±0.70% (p<0.001). IBGMS and RT-CGM did not show significantly different A1C levels at baseline, 3 and 6 months (p>0.05). CONCLUSIONS: The use of both IBGMS and RT-CGM significantly improved A1C levels in patients with type 2 diabetes treated with insulin in a randomized trial over a 6-month period. There were no significant differences in A1C values between groups after 6 months.

Directional learning, but no spatial mapping by rats performing a navigational task in an inverted orientation.

Previous studies have identified neurons throughout the rat limbic system that fire as a function of the animal's head direction (HD). This HD signal is particularly robust when rats locomote in the horizontal and vertical planes, but is severely attenuated when locomoting upside-down (Calton & Taube, 2005). Given the hypothesis that the HD signal represents an animal's sense of directional heading, we evaluated whether rats could accurately navigate in an inverted (upside-down) orientation. The task required the animals to find an escape hole while locomoting inverted on a circular platform suspended from the ceiling. In Experiment 1, Long-Evans rats were trained to navigate to the escape hole by locomoting from either one or four start points. Interestingly, no animals from the 4-start point group reached criterion, even after 29 days of training. Animals in the 1-start point group reached criterion after about six training sessions. In Experiment 2, probe tests revealed that animals navigating from either 1- or 2-start points utilized distal visual landmarks for accurate orientation. However, subsequent probe tests revealed that their performance was markedly attenuated when navigating to the escape hole from a novel start point. This absence of flexibility while navigating upside-down was confirmed in Experiment 3 where we show that the rats do not learn to reach a place, but instead learn separate trajectories to the target hole(s). Based on these results we argue that inverted navigation primarily involves a simple directional strategy based on visual landmarks.