Faculty Bibliography

Perception results from the interplay of sensory input and prior knowledge. Despite behavioral evidence that long-term priors powerfully shape perception, the neural mechanisms underlying these interactions remain poorly understood. We obtained direct cortical recordings in neurosurgical patients as they viewed ambiguous images that elicit constant perceptual switching. We observe top-down influences from the temporal to occipital cortex, during the preferred percept that is congruent with the long-term prior. By contrast, stronger feedforward drive is observed during the non-preferred percept, consistent with a prediction error signal. A computational model based on hierarchical predictive coding and attractor networks reproduces all key experimental findings. These results suggest a pattern of large-scale information flow change underlying long-term priors' influence on perception and provide constraints on theories about long-term priors' influence on perception.

OBJECTIVES/OBJECTIVE:We contrasted the relative risks (RR) of short [<7 h] and long [>8 h] sleep experienced by middle-aged (45-64 years) and older (≥65 years) adults, compared with young adults (20-44 years). METHODS:We utilized NHANES data (2005-2016), capturing sociodemographic, socioeconomic, and health-related data among US adults. RESULTS:The Relative Risk (RR) of short sleep between young and middle-aged adults did not differ [RR = 1.02, NS]. However, the RR of short sleep was significantly reduced among older participants [RR = 0.81, p < 0.01]. Middle-aged adults had significantly lower RR of long sleep [RR = 0.80, p < 0.01], whereas older adults had significantly greater RR of long sleep [RR = 1.41, p < 0.01]. Compared with young adults, older adults with or without increased disease burden had significantly lower RR of short sleep [RR = 0.81, p < 0.01 and RR = 0.80, p < 0.01], respectively. However, for middle-aged adults, the RR of short sleep did not differ whether they reported a greater disease burden. Relative to young adults, older adults with or without disease burden had higher RRs of long sleep [RR = 1.39, p < 0.01] and [RR = 1.45, p < 0.01], respectively. For middle-aged adults without disease burden, the RR of long sleep was lower than among young adults [RR = 0.72, p < 0.01]. CONCLUSIONS:Compared with young adults, older adults were not at increased risk for short sleep. Rather, they reported longer sleep time regardless of the presence of disease burden. Future studies should investigate longitudinal effects of aging on objective sleep time, with or without common diseases.

INTRODUCTION/BACKGROUND:Neonates with severe Pierre Robin sequence (PRS) can be treated by mandibular distraction osteogenesis (MDO), tongue-lip adhesion, or tracheostomy; however, there is an active debate regarding the indications of MDO in this patient population. Published algorithms identify tracheomalacia, bronchomalacia, laryngomalacia, hypotonic syndromes, and central sleep apnea as contraindications for MDO and indications for tracheostomy, but these comorbidities may exist along a spectrum of severity. The authors propose that appropriately selected neonates with PRS who concurrently express 1 or more of these traditional contraindications may be successfully treated with MDO. METHODS:The authors performed a 5-year retrospective chart review of all neonates who underwent MDO for treatment of severe PRS. All patients expressed a comorbidity previously identified as an indication for tracheostomy. Pre- and postoperative characteristics were recorded. Apnea/hypopnea index (AHI) before and after MDO were compared using 2-tailed repeated measures t-test. RESULTS:The authors identified 12 patients with severe PRS and conditions associated with contraindications to MDO: 9 (75.0%) patients had laryngomalacia, 6 (50.0%) patients had tracheomalacia, 2 (16.6%) patients had bronchomalacia, 1 (8.3%) patient had central sleep apnea, and 3 (25.0%) patients had hypotonia. Five (41.7%) patients underwent concurrent gastrostomy tube placement due to feeding insufficiency. Average birthweight was 3.0 kg. Average pre-op AHI was 34.8. Average post-op AHI was 7.3. All patients successfully underwent MDO with avoidance of tracheostomy. CONCLUSIONS:By employing an interdisciplinary evaluation of patient candidacy, MDO can safely and effectively treat upper airway obstruction and avoid tracheostomy in higher-risk neonatal patients with traditional indications for tracheostomy.

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PURPOSE OF REVIEW/OBJECTIVE:Patent foramen ovale (PFO) is widely prevalent and studies have suggested an association with ischemic stroke. In this review, we aim to highlight current management of patients with ischemic stroke in the setting of PFO and discuss some areas of controversy. RECENT FINDINGS/RESULTS:Upon reviewing the literature, we have found that the evidence regarding the management of patients with cryptogenic stroke and PFO has come a long way in the past several years, and many uncertainties remain in clinical practice. The Risk of Paradoxical Embolism (RoPE) score helps to predict the probability of a pathogenic PFO, and recent trial data confirms the benefit of closure in carefully selected patients. The benefit of closure in older patients and in patients with alternate, competing mechanisms is still uncertain, and the long-term risks of closure are not known. Finally, the efficacy of direct oral anticoagulants (DOACs) in this patient population as compared to other medical therapy or mechanical closure has not yet been investigated. Randomized data is needed to help answer these questions. PFO closure is a safe and effective strategy in reducing stroke risk in carefully selected patients with cryptogenic stroke in the setting of a PFO. More studies are needed to test optimal medical treatment strategies and the safety and efficacy of PFO closure in patient subgroups not included in prior PFO closure trials.

PURPOSE:To identify factors predictive of a large labral tear at the time of shoulder instability surgery. METHODS:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients undergoing open or arthroscopic shoulder instability surgery for a labral tear were evaluated. Patients with >270° tears were defined as having large labral tears. To build a predictive logistic regression model for large tears, the Feasible Solutions Algorithm was used to add significant interaction effects. RESULTS:After applying exclusion criteria, 1235 patients were available for analysis. There were 222 females (18.0%) and 1013 males (82.0%) in the cohort, with an average age of 24.7 years (range 12 to 66). The prevalence of large tears was 4.6% (n = 57), with the average tear size being 141.9°. Males accounted for significantly more of the large tears seen in the cohort (94.7%, P = .01). Racquet sports (P = .01), swimming (P = .02), softball (P = .05), skiing (P = .04), and golf (P = .04) were all associated with large labral tears, as was a higher Western Ontario Shoulder Instability Index (WOSI; P = .01). Age, race, history of dislocation, and injury during sport were not associated with having a larger tear. Using our predictive logistic regression model for large tears, patients with a larger body mass index (BMI) who played contact sports were also more likely to have large tears (P = .007). CONCLUSIONS:Multiple factors were identified as being associated with large labral tears at the time of surgery, including male sex, preoperative WOSI score, and participation in certain sports including racquet sports, softball, skiing, swimming, and golf. LEVEL OF EVIDENCE:I, prognostic study.

BACKGROUND:Kneeling posterior cruciate ligament (PCL) stress radiographs are commonly used to evaluate PCL laxity. Patients, however, report significant pain, and the method's reproducibility may be challenged due to its dependence on patient body weight distribution to produce posterior tibial displacement. Weighted gravity stress radiography may offer better reproducibility and comfort than the kneeling technique, but its efficacy has not been studied. HYPOTHESIS:Weighted gravity PCL stress radiographs will be more comfortable and produce similar measurements of side-to-side difference in posterior tibial displacement when compared with the kneeling technique. STUDY DESIGN:Cohort study (diagnosis); Level of evidence, 3. METHODS:tests were used to compare the side-to-side difference, pain score, and time to complete the radiographs. RESULTS:< .0001). Of the patients, 88% preferred the weighted gravity method. CONCLUSION:Weighted gravity stress radiographs produce similar side-to-side differences in posterior tibial translation compared with the kneeling stress technique, but do not rely on patient weightbearing and provide significantly better patient comfort. Clinicians should therefore consider the use of weighted gravity stress radiographs in clinical practice to minimize the pain associated with stress radiography while allowing for accurate decision making.

PURPOSE/OBJECTIVE:Subchondroplasty® is a novel minimally invasive procedure for painful subchondral bone marrow lesions (BMLs). The aim of this systematic review was to characterize the clinical outcomes of the Subchondroplasty® procedure, a novel minimally invasive procedure for the treatment of BMLs. The hypothesis tested was that patients experience improvements in pain and functional outcomes following the Subchondroplasty® procedure. METHODS:MEDLINE, Embase, Web of Science, and Clinicaltrials.gov were searched from database inception to search date (June 10, 2020) for all clinical studies which discussed Subchondroplasty®. Two reviewers independently screened 45 unique results and 17 studies were included in the final analysis. Data were collected regarding patient demographics, indications, pain, functional scores, conversion to TKA, and complications of the procedure. RESULTS:All but one study were level IV evidence; the mean MINORS score was 9 ± 2. There were 756 patients included, 45.1% were female, and the mean age was 54 years (range 20-85). Thirteen studies investigated the effect Subchondroplasty® to the knee, while four studied the impact on the foot and ankle. Median length of follow-up was 12 months. The most common indication for Subchondroplasty® was joint pain with corresponding BML. Major contraindications to Subchondroplasty® included severe OA, joint instability, and malalignment. Mean pain score on visual analogue scale (VAS) prior to Subchondroplasty® was 7.8 ± 0.6, but decreased to 3.4 ± 0.7 postoperatively. All studies investigating functional scores reported improvement following Subchondroplasty® (IKDC 31.7 ± 1.9-54.0 ± 4.2 and KOOS 38.1 ± 0.6-70.0 ± 4.1). There were consistently high levels of patient satisfaction; 87 ± 8% of patients would be willing to undergo the procedure again. Seven cases of complications were reported, most seriously osteomyelitis and avascular necrosis. Conversion to knee arthroplasty ranged from 12.5 to 30% with length of follow-up ranging from 10 months to 7 years. CONCLUSIONS:Existing low-quality studies show Subchondroplasty® to benefit patients with BMLs through reduction in pain and improvement in function, along with a high degree of satisfaction following the procedure. The low short-to-medium term conversion rate to arthroplasty suggests that Subchondroplasty® may play a role in delaying more invasive and expensive procedures in patients with BMLs. Subchondroplasty® is a novel procedure that has promising initial findings, but requires further high-quality, comparative studies with long-term follow-up to better understand the outcomes of the procedure and impact clinical practice recommendations. LEVEL OF EVIDENCE/METHODS:Systematic Review of Level III and IV Studies, Level IV.