Charles Bae

The use of sleep studies in neurologic practice.

Sleep medicine is a multidisciplinary specialty that is rapidly advancing with exciting new discoveries. Some sleep disorders are diagnosed by clinical history alone, but others such as sleep apnea, narcolepsy, periodic limb movement disorder, parasomnias, and nocturnal seizures (conditions that will be addressed by other articles in this issue) usually require evaluation in the sleep laboratory. Sleep studies are used for diagnostic purposes, to assess disease severity, and to evaluate treatment efficacy. Routine sleep testing can be tailored to answer the specific clinical question at hand. In this article, the authors review the most commonly performed sleep tests in the sleep laboratory and their indications, interpretation, and limitations. These include the polysomnogram (PSG), the Multiple Sleep Latency Test (MSLT), the Maintenance of Wakefulness Test (MWT), and actigraphy. The accurate interpretation of these studies requires a comprehensive sleep and medical history.

Referral Patterns and Positive Airway Pressure Adherence upon Diagnosis of Obstructive Sleep Apnea

Objective Obstructive sleep apnea (OSA) is a serious medical condition that adds to patient morbidity and mortality. Treatment with positive airway pressure (PAP) is the standard of care, but many patients refuse or do not tolerate PAP. Little is known about the subsequent management of these patients. We sought to understand what types of treatment, if any, adult patients with OSA receive who either fail or refuse PAP therapy within our institution. Study Design Retrospective chart review. Setting Academic hospital. Subjects All adult patients undergoing polysomnogram during the months of March and April 2010 (n = 1174) who were diagnosed with OSA. Methods The electronic medical record was reviewed to determine the subsequent management of patients with a diagnosis of OSA, including tolerance or failure of PAP and referral to specialists upon intolerance. Results Of 1174 patients, 616 met inclusion criteria. Ultimately, 260 (42%) had documented adherence to PAP. Of 241 untreated patients, 84 patients (35%) were referred for further attempts at management of diagnosed OSA. Nearly half of patients with diagnosed OSA did not have continued treatment or referral. Conclusion To our knowledge, this is the first study to define the subsequent management of patients who have failed or refused PAP. Despite the known sequelae of OSA, clinicians are not treating a significant percentage of patients with diagnosed OSA. Those who fail to tolerate PAP therapy are unlikely to be referred for additional treatment. Therapies other than PAP may be warranted in this population.

The Challenges of Data Quality Evaluation in a Joint Data Warehouse.

Introduction: The use of clinically derived data from electronic health records (EHRs) and other electronic clinical systems can greatly facilitate clinical research as well as operational and quality initiatives. One approach for making these data available is to incorporate data from different sources into a joint data warehouse. When using such a data warehouse, it is important to understand the quality of the data. The primary objective of this study was to determine the completeness and concordance of common types of clinical data available in the Knowledge Program (KP) joint data warehouse, which contains feeds from several electronic systems including the EHR. Methods: A manual review was performed of specific data elements for 250 patients from an EHR, and these were compared with corresponding elements in the KP data warehouse. Completeness and concordance were calculated for five categories of data including demographics, vital signs, laboratory results, diagnoses, and medications. Results: In general, data elements for demographics, vital signs, diagnoses, and laboratory results were present in more cases in the source EHR compared to the KP. When data elements were available in both sources, there was a high concordance. In contrast, the KP data warehouse documented a higher prevalence of deaths and medications compared to the EHR. Discussion: Several factors contributed to the discrepancies between data in the KP and the EHR—including the start date and frequency of data feeds updates into the KP, inability to transfer data located in nonstructured formats (e.g., free text or scanned documents), as well as incomplete and missing data variables in the source EHR. Conclusion: When evaluating the quality of a data warehouse with multiple data sources, assessing completeness and concordance between data set and source data may be better than designating one to be a gold standard. This will allow the user to optimize the method and timing of data transfer in order to capture data with better accuracy.

Sleep Surgery Variations: The Evolution of Surgery for Obstructive Sleep Apnea at an Academic Hospital

Objectives: (1) Identify surgeon dependent and temporal variations in indications and surgical interventions for obstructive sleep apnea (OSA) at a tertiary academic hospital. (2) Clarify if volume of sleep surgeries performed affects outcomes. (3) Determine if surgical volume correlates with technical variation (ie, do surgeons who perform more surgeries for OSA perform additional procedures beyond uvulopalatopharyngoplasty [UPPP]). Methods: Retrospective chart review: Adult patients who had undergone UPPP since 2003 and had electronic medical records available were included. Quality of life (QOL) instruments included in the electronic medical record such as the Epworth Sleepiness Scale (ESS) and the Functional Outcomes of Sleep Questionnaire (FOSQ) were included. Pre- and postoperative results were compared using standard statistical analysis. Results: A total of 247 patients met inclusion criteria. Median AHI of all patients with available postoperative PSG decreased from 39.4 to 21.4. Patients of high-volume surgeons (>10 UPPP per year) were more likely to have a lower preoperative Friedman score (P < .02), complete a postoperative PSG (P < .0001 by the 2-tailed Fisher exact test), have a decreased postoperative ESS (P < .01), and have a PSG completed sooner after surgery (P < .01). Postoperative AHI and change in AHI did not differ between groups, however (P = .21 and P = .14, respectively). Conclusions: UPPP contributes to objective improvement in PSG measures and quality of life. Nuances in patient selection and patient management are apparent between high volume surgeons and others, and may contribute to quality of life variations. Standardization of patient selection, timing of postoperative PSG, and increased utilization of QOL instruments may improve QOL outcomes among surgeons who do not perform UPPP regularly.

Sleep and Neurologic Disorders

The chapter topics will focus on the most commonly encountered neurologic disorders in the sleep patient, such as peripheral neuropathy in the setting of restless legs syndrome, stroke and sleep-disordered breathing, the differentiation of nocturnal seizures and parasomnias, and hypersomnia with secondary neurologic causes. Other neurologic problems encountered include neurodegenerative diseases, headaches, head trauma, brain tumors, and neuromuscular disease.