Stimulation-induced entrainment of hippocampal network activity: Identifying optimal input frequencies

The hippocampus contains rich oscillatory activity, with continuous ebbs and flows of rhythmic currents that constrain its ability to integrate inputs. During associative learning, the hippocampus must integrate inputs from a range of sources carrying information about events and the contexts in which they occur. Under these circumstances, temporal coordination of activity between sender and receiver is likely essential for successful communication. Previously, it has been shown that the coordination of rhythmic activity between the lateral entorhinal cortex (LEC) and the CA1 region of the hippocampus is tightly correlated with the onset of learning in an associative learning task. We aimed to examine whether rhythmic inputs from the LEC in specific frequency ranges were sufficient to enhance the temporal coordination of activity in downstream CA1. In urethane-anesthetized rats, we applied extracellular low-intensity alternating current stimulation across the length of the LEC. Using this method, we aimed to phase-bias ongoing neuronal activity in LEC at a range of different frequencies (from 1.25 to 55 Hz). Rhythmic stimulation of LEC at both 35 and 50 Hz increased the proportion of CA1 neurons significantly entrained to the phase of the applied stimulation current. A subset of stimulation frequencies modified CA1 spiking relationships to the phase of local ongoing CA1 oscillations, with each stimulation frequency exerting a unique influence upon downstream CA1, often in frequency ranges outside the target stimulation frequency. These results suggest there are optimal frequencies for LEC-CA1 communication, and that different profiles of LEC rhythms likely have distinct outcomes upon CA1 processing.

Interpreter Use and Patient Satisfaction in the Otolaryngology Outpatient Clinic

Background

Communication between providers and patients is essential to patient care and to the patient-physician relationship. It plays a significant role in both measurable and perceived quality of care. This study explores the satisfaction of English-speaking and limited English proficiency (LEP) patients with English-speaking providers, focusing on the correlation between patients’ primary language and the use of interpreter services on patients’ visit satisfaction.

Methodology

This study was designed to have a sample size sufficient to detect a 10% difference in the primary outcome, overall visit satisfaction, between language-concordant patients and LEP patients in the interpreter and no interpreter groups, assuming a two-tailed alpha of 0.05 and power of 80%. All collected data were analyzed using the Statistical Package for the Social Sciences software, version 25 (IBM Corp, Armonk, NY, USA), and significance was determined if p <0.05.

Results

Of the total 209 patients, 65 utilized professional interpreter services, nine used an ad-hoc interpreter, and 135 did not require an interpreter. Patients who used an interpreter demonstrated lower visit satisfaction compared with patients who did not (p < 0.001). Patients expressed significantly greater preference for in-person interpreter (mean = 9.73) or a family member (mean = 9.44) compared to telephone services (mean = 8.50) (p = 0.002). The overall satisfaction scores did not significantly differ between different interpreter types (p = 0.157).

Conclusions

LEP patients experienced lower visit satisfaction compared to language-concordant patients. The data suggest that perceived quality of communication was a factor in these lower satisfaction reports. While LEP patients did prefer in-person interpreters, there was no significant difference in overall visit satisfaction between different types of interpreters.

Evaluating Factors That Influence Patient Satisfaction in Otolaryngology Clinics

OBJECTIVES

To identify factors that influence patient satisfaction during outpatient visits in various settings of otolaryngology clinics in an academic medical center.

STUDY DESIGN

Retrospective review.

SETTING

Academic medical center.

METHODS

We reviewed Press Ganey patient satisfaction survey responses for new, outpatient visits between January 1, 2014 and December 31, 2018. Self-reported race was identified using electronic medical records. Multivariate binary logistic regression analyses were used to identify continuous and categorical variables associated with patient satisfaction.

RESULTS

There were 3998 unique new patient visits with completed surveys. Multivariate analysis revealed that responses for patients <18 years old are less likely to be satisfied with their care compared to patients ≥18 years old (OR 0.66; P < .001). For each 10-minute increase in wait time, patients were 43.4% less likely report satisfaction (P < .001). African American patients were also less likely to report satisfaction (OR 0.22; P = .043) while Native Hawaiian and Pacific Islanders were over 3 times more likely to be satisfied (OR 3.6; P = .013). Additionally, Medicare patients and those who were seen at community satellite clinics compared to the main University Hospital had increased odds of achieving satisfactory care (OR 1.3; P = .005 and OR 1.3; P = .002, respectively).

CONCLUSIONS

Wait time, clinic location, patient race, insurance provider, and age were all shown to significantly influence patient-reported satisfaction. Understanding how these variables influence patient satisfaction will hopefully lead to processes that improve patient satisfaction.

LEVEL OF EVIDENCE

Level 3.

Factors Affecting Compliance With Myringotomy Tube Follow-up Care

OBJECTIVE

Myringotomy and tube insertion is a commonly practiced procedure within pediatric otolaryngology. Though relatively safe, follow-up appointments are critical in preventing further complications and monitoring for improvement. This study sought to evaluate the factors associated with compliance of post-myringotomy follow-up visits in an urban safety-net tertiary care setting.

METHODS

This study is a retrospective chart review conducted in outpatient otolaryngology clinic at an urban, safety-net, tertiary-care, academic medical center. All patients from ages 0 to 18 who received myringotomy and tube placement between February 3, 2012, to May 30, 2018 at the aforementioned clinic were included.

RESULTS

A total of 806 patients had myringotomy tubes placed during this period; 190 patients were excluded due to no visits being scheduled within 1 and 6 month visit windows post-operatively, leaving 616 patients included for analysis. Of 616 patients, 574 patients were seen for the 1-month visit, (42 patients did not have follow-up visits within the 1-month window), and 356 patients were examined for the 6-month visit (260 patients did not schedule follow-up visits within the 6-month window). For the 1-month follow-up visits post-procedure, only race/ethnicity type "Other" was associated with lower no-show rates (OR = 0.330, 95% CI: 0.093-0.968). With the 6-month follow-up visits, having private insurance (OR = 0.446, 95% CI: 0.229-0.867) and not having a 1-month visit scheduled (OR = 0.404, 95% CI: 0.174-0.937) predicted lower no-show rates.

CONCLUSION

No meaningful factors studied were significantly associated with compliance of short-term, 1-month visits post-myringotomy. Compliance of longer-term, 6-month post-operative visits was associated with insurance type and previous visit status.

Alternatives to Acid Suppression Treatment for Laryngopharyngeal Reflux

OBJECTIVE

Laryngopharyngeal reflux (LPR) and associated symptoms can be refractory to treatment with acid suppressing medication. We investigated the role and evidence for complementary and alternative medicine (CAM) for LPR in this systematic review.

REVIEW METHODS

Complementary and alternative treatment was defined in this systematic review as any non-acid suppressing medication, treatment, or therapy. A literature search was performed by two authors in consultation with a medical librarian using controlled vocabulary for "complementary and alternative medicine" and "laryngopharyngeal reflux" in the databases PubMed and EMBASE, with supplemental searches with Google Scholar.

RESULTS

Twenty articles were included in this review for the modalities: alginate, diet modification, prokinetics, respiratory retraining, voice therapy, rikkunshito (RKT), hypnotherapy, and sleep positioning. The studies were analyzed for bias based on the Cochrane criteria for RCTs and Methodological Index for non-RCT (MINORS) criteria for all other studies. For each modality a level of evidence was assigned to the current body of evidence using the GRADE approach.

CONCLUSION

There is mixed evidence with a high degree of bias and heterogeneity between studies for the modalities presented in the paper. Based on this review, an anti-reflux diet is recommended for all patients and there is some low-quality evidence to support alkaline water. For patients with predominant vocal symptoms there is evidence that supports voice therapy. There is insufficient evidence to recommend prokinetics at this time. For patients with predominant globus symptoms, alginate, RKT, and relaxation strategies may be used in conjunction with acid suppressing medications for symptom relief.

The Impact of Medical Scribes on Patient Satisfaction in an Academic Otolaryngology Clinic

Objectives:

Evidence shows that scribes can improve provider efficiency and satisfaction in several settings, but is mixed on whether scribes improve patient satisfaction. We studied whether scribes improved patient satisfaction in an academic otolaryngology clinic.

Methods:

The authors performed a retrospective review of patient responses to the Press Ganey survey between 12/2016 and 12/2017. Their responses about satisfaction with the provider and wait times were examined. Three providers worked with scribes during this year; each spent six months with a scribe and six without. The authors compared survey responses from periods with and without scribes using the Fischer exact test. Average overall provider ratings were compared using the Student’s t-test.

Results:

A total of 87 patients filled out Press Ganey surveys for the 3 providers over the year: 54 for visits without scribes, and 33 for visits with scribes. Fischer exact analysis demonstrated no significant difference in satisfaction with providers and wait times for both individual providers and all providers combined (all P > .05). There was also no difference in patients’ likelihood of recommending the provider’s office ( P = .91). Overall provider rating (0-10 scale) was high without scribes (9.48 ± 1.06) and was unchanged by the presence of scribes (9.53 ± 0.8) ( P = .97).

Conclusion:

Patient satisfaction with wait times and providers was high overall and was not affected by the presence of a medical scribe.

The shifting relationship between weight and pediatric obstructive sleep apnea: A historical review

OBJECTIVES

For more than a century, pediatric obstructive sleep apnea (OSA) was associated with failure to thrive. However, that association has faded over the last few decades. A 21st century child with OSA is much more likely to be overweight than underweight. This raises the question: Has pediatric OSA changed over time, or has the rise of childhood obesity in the United States created a new, separate disease? This literature review explores the historical shift in the relationship between weight and OSA, and the associated changes in treatment.

RESULTS

We demonstrate a clear transition in the prevalence of failure to thrive and obesity in the OSA literature in the mid-2000s. What is less clear is whether these two clinical phenotypes should be considered two distinct diseases, or whether subtle differences in one set of pathophysiologic pathways-adenotonsillar hypertrophy, altered inflammation, and increased energy expenditure-can lead to divergent metabolic outcomes. More research is needed to fully elucidate the pathophysiology of OSA in children with obesity.

CONCLUSIONS

We may need new and different treatments for obesity-associated OSA as adenotonsillectomy-which is effective at reversing failure to thrive in OSA-is not as effective at treating OSA in children with obesity. One option is drug-induced sleep endoscopy, which could personalize and improve surgical treatment of OSA. There is some evidence that therapies used for OSA in adults (e.g., weight loss and positive airway pressure) are also helpful for overweight/obese children with OSA. Laryngoscope, 129:2414-2419, 2019.

Compliance With Subcutaneous Immunotherapy Appointments in an Urban Tertiary Care Setting

INTRODUCTION

Subcutaneous immunotherapy (SCIT) is an effective treatment for allergic disease such as allergic rhinitis and asthma. Reported adherence rates to SCIT have been low, ranging between 50% and 89%. This study sought to evaluate compliance to SCIT in an urban "safety net," tertiary care center, and to evaluate for disparities in compliance based upon insurance and socioeconomic status.

METHODS

A retrospective chart review of SCIT patients between 2003 and 2016 was performed. Demographic data, insurance carriers, and comorbidities were collected. Compliance was evaluated on treatment adherence (percentage of injections administered/scheduled appointments). Statistical analysis was performed using R statistical software. Linear regression analysis was performed to compare compliance to the variables, asthma, duration of therapy, payor, and age. Analysis of variance was used to compare mean compliance between payor groups.

RESULTS

Two hundred five patients met our inclusion criteria and 28 were excluded. Insurance composition was Medicaid (67, 33%), Medicare (18, 9%), Health Safety Net (HSN) in Massachusetts (33, 16%), and commercial payors (82, 42%). Linear regression demonstrated that age, duration of therapy, and asthma status were not related to the percentage of missed doses ( P > .05). Payor status was statistically predictive of missed doses ( P = .02). When comparing average percentage of missed immunotherapy shots, Medicaid patients missed the most 34.2%, followed by Medicare 24.4%, commercial insurance 19.9%, and HSN in Massachusetts 18.5% ( P ≤ .02).

CONCLUSION

In a cohort of patients at a tertiary care "safety-net" center serving a low-income population, compliance to SCIT was found to be overall high but lower in the Medicaid population.

Treating pediatric post-tonsillectomy pain and nausea with complementary and alternative medicine

OBJECTIVES

Although tonsillectomy is a common and largely safe procedure, pain management in children remains a controversial topic. In addition to the challenge of choosing appropriate analgesia, there is often low parent and child adherence. This article presents a review, and evaluates the potential role, of a range of complementary and alternative therapies that may be sought out by parents.

METHODS

A literature review of complementary and alternative interventions performed using PubMed, Cochrane Library, and EMBASE, supplemented by searches from Google and hand searches of cross-references of selected articles, yielded 32 studies for qualitative analysis.

RESULTS

The studies included for analysis investigated a wide variety of alternative treatment modalities: acupuncture and related therapies, aromatherapy, homeopathy, honey, intravenous fluid, speech therapy, hyaluronic acid, behavioral therapies, ice/cold, hydrogen peroxide rinse, and chewing gum.

CONCLUSION

At this time, stronger conclusions cannot be made about the therapies investigated because there are many methodology limitations of the studies analyzed. However, our results suggest merit for these treatments as adjuvant therapies that can enhance analgesia and decrease requirements of controversial medications. Honey and acupuncture have the greatest amount of evidence for postoperative pain and nausea; however, all interventions examined were cost-effective and safe. We recommend against hydrogen peroxide rinses and chewing gum. Laryngoscope, 2625-2634, 2018.

Rhythmic coordination of hippocampal neurons during associative memory processing

Hippocampal oscillations are dynamic, with unique oscillatory frequencies present during different behavioral states. To examine the extent to which these oscillations reflect neuron engagement in distinct local circuit processes that are important for memory, we recorded single cell and local field potential activity from the CA1 region of the hippocampus as rats performed a context-guided odor-reward association task. We found that theta (4–12 Hz), beta (15–35 Hz), low gamma (35–55 Hz), and high gamma (65–90 Hz) frequencies exhibited dynamic amplitude profiles as rats sampled odor cues. Interneurons and principal cells exhibited unique engagement in each of the four rhythmic circuits in a manner that related to successful performance of the task. Moreover, principal cells coherent to each rhythm differentially represented task dimensions. These results demonstrate that distinct processing states arise from the engagement of rhythmically identifiable circuits, which have unique roles in organizing task-relevant processing in the hippocampus.

DOI:http://dx.doi.org/10.7554/eLife.09849.001

Electrodes placed on the surface of the scalp can reveal rhythmic patterns of electrical activity within the brain. These rhythms reflect the coordinated firing of large numbers of neurons that are connected together within a network in order to process information. A single network can show rhythms with various different frequencies depending on its local connections and the pattern of input that it receives at any given time.

One region that exhibits striking changes in these rhythmic patterns is the hippocampus: a brain area that plays a key role in memory. The hippocampus contains many cell types, including interneurons (which form connections with nearby cells) and principal cells (which connect with cells outside of this region). Though both participate in rhythmic circuits, little is known about the different extents to which these distinct cell types are engaged in rhythmic processing, or how rhythmic processing might support memory.

Rangel, Rueckemann, Rivière et al. have now addressed these questions by using electrodes to record from the hippocampus as rats learned to associate specific odors in different environments with a reward. As the rats sniffed the odors, their brains showed four different hippocampal rhythms: from a low frequency called “theta”, through “beta” and “low gamma” up to “high gamma” frequencies. Each of these hippocampal rhythms varied in strength over time, indicating that rhythmic processing is dynamic during the task.

Rangel, Rueckemann, Rivière et al. found that neurons fired rhythmically during trials in which the rat chose the correct odor-environment combination. In these correct trials, individual principal cells were more likely to fire in synchrony with only one of the rhythms. In contrast, interneurons were more likely to fire in synchrony to each of the four rhythms at some point during a correct choice. Among the four rhythms, coordinated principal cell and interneuron firing with respect to the beta rhythm was most tightly linked with a correct choice. These findings reveal that investigation of rhythmic dynamics in the hippocampus can provide insight into how the timing of cell activity is coordinated to support memory.

DOI:http://dx.doi.org/10.7554/eLife.09849.002