Optical absorption spectra and corresponding in vivo photoacoustic visualization of exposed peripheral nerves.

Significance: Multispectral photoacoustic imaging has the potential to identify lipid-rich, myelinated nerve tissue in an interventional or surgical setting (e.g., to guide intraoperative decisions when exposing a nerve during reconstructive surgery by limiting operations to nerves needing repair, with no impact to healthy or regenerating nerves). Lipids have two optical absorption peaks within the NIR-II and NIR-III windows (i.e., 1000 to 1350 nm and 1550 to 1870 nm wavelength ranges, respectively) which can be exploited to obtain photoacoustic images. However, nerve visualization within the NIR-III window is more desirable due to higher lipid absorption peaks and a corresponding valley in the optical absorption of water. Aim: We present the first known optical absorption characterizations, photoacoustic spectral demonstrations, and histological validations to support in vivo photoacoustic nerve imaging in the NIR-III window. Approach: Four in vivo swine peripheral nerves were excised, and the optical absorption spectra of these fresh ex vivo nerves were characterized at wavelengths spanning 800 to 1880 nm, to provide the first known nerve optical absorbance spectra and to enable photoacoustic amplitude spectra characterization with the most optimal wavelength range. Prior to excision, the latter two of the four nerves were surrounded by aqueous, lipid-free, agarose blocks (i.e., 3% w/v agarose) to enhance acoustic coupling during in vivo multispectral photoacoustic imaging using the optimal NIR-III wavelengths (i.e., 1630 to 1850 nm) identified in the ex vivo studies. Results: There was a verified characteristic lipid absorption peak at 1725 nm for each ex vivo nerve. Results additionally suggest that the 1630 to 1850 nm wavelength range can successfully visualize and differentiate lipid-rich nerves from surrounding water-containing and lipid-deficient tissues and materials. Conclusions: Photoacoustic imaging using the optimal wavelengths identified and demonstrated for nerves holds promise for detection of myelination in exposed and isolated nerve tissue during a nerve repair surgery, with possible future implications for other surgeries and other optics-based technologies.

Selective Thumb Carpometacarpal Joint Denervation Versus Trapeziectomy and Ligament Reconstruction With Tendon Interposition for Painful Arthritis: A Prospective Study With 2 Years of Follow-Up.

PURPOSE: Thumb carpometacarpal (CMC) joint denervation is a relatively novel method for the management of osteoarthritis-associated pain by selective transection of articular nerve branches of the CMC joint. This study compared functional/patient-reported outcomes after CMC denervation with those after trapeziectomy and ligament reconstruction with tendon interposition (T + LRTI) over a 2-year follow-up period. We hypothesized that the outcomes of denervation and T + LRTI would be similar over the course of the study and at the final 2-year follow-up. METHODS: Adults with Eaton stage 2-4 disease, no evidence of CMC subluxation, and no history of thumb injury/surgery were included. Pain scores, brief Michigan Hand Questionnaire (bMHQ), Kapandji score, 2-point discrimination, and grip/key/3-point pinch strength were measured at 3-, 6-, 12-, and 24-months after surgery. On average, T + LRTI patients underwent 7 weeks of splinting, with release to full activity at 3 months; denervation patients were placed in a soft postoperative dressing for 2 weeks, with release to full activity as tolerated at 3 weeks. RESULTS: Thirty-three denervation and 20 T + LRTI patients were included. Preoperative characteristics were similar between both groups. Two denervation patients underwent secondary T + LRTI during the study period; one denervation patient underwent fat grafting to the CMC joint at an outside institution. Data prior to secondary surgeries were included in the analysis. The average tourniquet times (minutes) for denervation and T + LRTI were 43.5 ± 11.8 and 82.7 ± 14.2 minutes, respectively. For denervation and T + LRTI, the postoperative bMHQ scores were significantly higher than those at baseline at all time points. No significant differences were found between both groups for bMHQ, sensation, or strength measures. CONCLUSIONS: Carpometacarpal denervation is well tolerated, with shorter tourniquet times and faster return to full activity than T + LRTI. For the study cohort, the conversion rate to T + LRTI at 2 years was 9%. Both procedures demonstrated durable improvement in bMHQ compared with the preoperative state with similar long-term outcomes over 2 years of follow-up. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Decompression with Brachioradialis Tenotomy Improves Pain and Quality of Life in Patients with Radial Sensory Nerve Compression.

BACKGROUND: Decompression of the superficial sensory branch of the radial nerve (SBRN) with complete brachioradialis tenotomy may treat pain in both simple and complex cases of SBRN compression neuropathy. METHODS: A retrospective chart review was performed of consecutive patients undergoing this procedure between 2008 and 2020 including postoperative outcomes within 90 days. Data were collected and analyzed, including patient and injury demographics, pain descriptors, and patient-reported pain questionnaire, including reported pain severity and impact on quality of life using visual analogue scale (VAS) instruments. Within-group presurgical and postsurgical analyses and between-group statistical analyses were performed. RESULTS: Thirty-three of 58 patients met inclusion criteria. Median time from symptom onset to surgery was 300 days, and median postoperative follow-up time was 37 days. Twenty-five percent of patients ( n = 8) underwent isolated SBRN decompression. The remainder had concomitant decompression of another radial [ n = 16 (48%) or peripheral [ n = 12 (36%)] entrapment point. Ten of 33 patients (30%) had resolution of pain at final follow-up ( P = 0.004). Median change in worst pain over the previous week was -4 ( P < 0.001), and average pain over the last month was -2.75 ( P < 0.001) on the VAS. The impact of pain on quality of life showed a median change of -3 ( P < 0.001) on the VAS. CONCLUSION: Decompression of the sensory branch of the radial nerve including a complete brachioradialis tenotomy improves pain and quality-of-life VAS scores in patients with both simple compression neuropathy syndrome and complex nerve compression syndrome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Beyond the Cubital Tunnel: Use of Adjunctive Procedures in the Management of Cubital Tunnel Syndrome.

BACKGROUND: Our management of cubital tunnel syndrome has expanded to involve multiple adjunctive procedures, including supercharged end-to-side anterior interosseous to ulnar nerve transfer, cross-palm nerve grafts from the median to ulnar nerve, and profundus tenodesis. We also perform intraoperative brief electrical stimulation in patients with severe disease. The aims of this study were to evaluate the impact of adjunctive procedures and electrical stimulation on patient outcomes. METHODS: We performed a retrospective review of 136 patients with cubital tunnel syndrome who underwent operative management from 2013 to 2018. A total of 38 patients underwent adjunctive procedure(s), and 33 received electrical stimulation. A historical cohort of patients who underwent cubital tunnel surgery from 2009 to 2011 (n = 87) was used to evaluate the impact of adjunctive procedures. Study outcomes were postoperative improvements in Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire scores, pinch strength, and patient-reported pain and quality of life. RESULTS: In propensity score-matched samples, patients who underwent adjunctive procedures had an 11.3-point greater improvement in DASH scores than their matched controls (P = .0342). In addition, patients who received electrical stimulation had significantly improved DASH scores relative to baseline (11.7-point improvement, P < .0001), whereas their control group did not. However, when compared between treatment arms, there were no significant differences for any study outcome. CONCLUSIONS: Patients who underwent adjunctive procedures experienced greater improvement in postoperative DASH scores than their matched pairs. Additional studies are needed to evaluate the effects of brief electrical stimulation in compression neuropathy.

Developing a Video-Based Learning Module to Teach Decision-Making for Cubital Tunnel Surgery.

BACKGROUND: Although intraoperative educational videos have become increasingly popular, comparatively few videos teach clinical reasoning for surgical procedures. The objectives of this study were to develop an engaging online video-based module to teach decision-making for cubital tunnel surgery, including supercharge nerve transfer, using a multimedia learning framework; and evaluate its effectiveness and use for continuing professional development. METHODS: The educational module consisted of a prelecture knowledge assessment, choice of two self-guided video lectures (7 minutes and 28 minutes), and a postlecture knowledge assessment. An additional assessment examined knowledge retention 3 months after module completion. Surgeon surveys were administered after each knowledge assessment. RESULTS: A total of 279 surgeons participated in the educational module (75 percent practicing surgeons, 25 percent trainees), 112 surgeons completed the postlecture assessment, and 71 surgeons completed the knowledge retention assessment. Median score on the prelecture assessment was five out of 10 (interquartile range, four to seven). Scores improved by three points (10-point scale; p < 0.0001) in the postlecture assessment. Median score on the knowledge retention assessment was eight out of 10 (interquartile range, six to nine), with participants maintaining a two-point increase from their prelecture score ( p = 0.0002). Among surgeons completing this assessment, 68 percent reported that the module had changed their management of cubital tunnel syndrome. CONCLUSIONS: This study introduces a framework for the development of online multimedia modules for surgical education. It also underscores a demand among surgeons for easily accessible, reusable educational resources. Similar video-based modules may be developed to address this demand to facilitate continuing professional development in surgery.

Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters.

BACKGROUND: Current classifications for cubital tunnel syndrome have not been shown to reliably predict postoperative outcomes. In this article, the authors introduce a new classification that incorporates clinical and electrodiagnostic parameters, including compound muscle action potential amplitude, to classify the preoperative severity of cubital tunnel syndrome. The authors compare this to established classifications and evaluate its association with patient-rated improvement. METHODS: The authors reviewed 44 patients who were treated surgically for cubital tunnel syndrome. Patients were retrospectively classified using their proposed classification and the Akahori, McGowan-Goldberg, Dellon, and Gu classifications. Correlation of grades was assessed by Spearman coefficients and agreement was assessed by weighted kappa coefficients. Patient-reported impairment was assessed using the Disabilities of the Arm, Shoulder, and Hand questionnaire before and after surgery. RESULTS: The classifications tended to grade patients in a similar way, with Spearman coefficients of 0.60 to 0.85 ( p < 0.0001) and weighted kappa coefficients of 0.46 to 0.71 ( p < 0.0001). Preoperative Disabilities of the Arm, Shoulder, and Hand scores increased with severity grade for most classifications. In multivariable analysis, the authors' classification predicted postoperative Disabilities of the Arm, Shoulder, and Hand score improvement, whereas established classifications did not. CONCLUSIONS: Established classifications are imperfect indicators of preoperative severity. The authors introduce a preoperative classification for cubital tunnel syndrome that incorporates electrodiagnostic findings in addition to classic signs and symptoms. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, III.

Incidence of Nerve Injury After Extremity Trauma in the United States.

BACKGROUND: Traumatic peripheral nerve injuries cause chronic pain, disability, and long-term reductions in quality of life. However, their incidence after extremity trauma remains poorly understood. METHODS: The IBM® MarketScan® Commercial Database from 2010 to 2015 was used to identify patients aged 18 to 64 who presented to emergency departments for upper and/or lower extremity traumas. Cumulative incidences were calculated for nerve injuries diagnosed within 2 years of trauma. Cox regression models were developed to evaluate the associations between upper extremity nerve injury and chronic pain, disability, and use of physical therapy or occupational therapy. RESULTS: The final cohort consisted of 1 230 362 patients with employer-sponsored health plans. Nerve injuries were diagnosed in 2.6% of upper extremity trauma patients and 1.2% of lower extremity trauma patients. Only 9% and 38% of nerve injuries were diagnosed by the time of emergency department and hospital discharge, respectively. Patients with nerve injuries were more likely to be diagnosed with chronic pain (hazard ratio [HR]: 5.9, 95% confidence interval [CI], 4.3-8.2), use physical therapy services (HR: 10.7, 95% CI, 8.8-13.1), and use occupational therapy services (HR: 19.2, 95% CI, 15.4-24.0) more than 90 days after injury. CONCLUSIONS: The incidence of nerve injury in this national cohort was higher than previously reported. A minority of injuries were diagnosed by emergency department or hospital discharge. These findings may improve practitioner awareness and inform public health interventions for injury prevention.

Long-Term Effects of Nasoalveolar Molding in Patients With Unilateral Cleft Lip and Palate: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis was to investigate long-term treatment effects of nasoalveolar molding (NAM) in patients with unilateral cleft lip and palate (UCLP). DESIGN: Included manuscripts met the following criteria: (1) involved patients with UCLP who received NAM; (2) included comparison group(s) who either received non-NAM passive presurgical infant orthopedic appliances (PSIO) or who did not receive any PSIO; (3) reported at least one objective or validated measure of nasolabial, craniofacial, or palatal form; and (4) had patient follow-up beyond 4 years of age. RESULTS: A total of 12 studies were included in this review. Meta-analyses were possible for Asher-McDade parameters and cephalometric measurements. Compared to patients who did not receive any PSIO, those who underwent NAM therapy were more likely to have good to excellent frontal nasal form (Risk ratio: 2.4, 95% CI: 1.24-3.68) and vermillion border (Risk ratio: 1.8, 95% CI: 1.19-2.71). However, there were no statistically significant differences in cephalometric measurements between these groups. Additionally, there were no statistically significant differences between patients receiving NAM versus non-NAM PSIO. There was insufficient evidence to determine the impact of NAM on dental arch development. CONCLUSIONS: The preponderance of evidence in this review suggests that NAM produces benefits in nasolabial aesthetic form when compared with no appliance-based presurgical treatment. However, there is insufficient evidence to conclude whether NAM produces such benefits when compared with other passive PSIOs.

Evaluation of Discipline-Specific Outcomes Through a Multidisciplinary Team Clinic for Patients With Isolated Cleft Palate.

OBJECTIVE: To describe the incidence and timing of provider-specific interventions for children with isolated cleft palate. DESIGN: This was a retrospective cohort study involving review of medical records. SETTING: Multidisciplinary team care clinic at a tertiary academic children's hospital between January 2000 and July 2019. PATIENTS: Patients with isolated nonsyndromic cleft palate seen by an American Cleft Palate-Craniofacial Association-approved team; 138 children were included. MAIN OUTCOME MEASURES: Study outcomes included incidence of secondary velopharyngeal management, tympanostomy tube insertion, speech therapy, hearing loss, dental/orthodontic treatment, and psychology interventions. Provider-specific outcomes were calculated for patients at ages 0 to 3, 3 to 5, and >5 years. RESULTS: Median follow-up time was 7.0 years (interquartile range: 3.3-11.8 years). At their last team assessment, 42% of patients still had conductive hearing loss. The rate of tympanostomy tube insertions not done alongside a palatoplasty was highest for ages 3 to 5 and dropped after new American Academy of Otolaryngology-Head and Neck Surgery Foundation guidelines in 2013 (P = .015); 54% of patients received speech-language therapy during follow-up. Palatoplasty, psychology, and dental/orthodontic treatment were all less common than speech or ENT treatment (P < .01). Secondary palatoplasty was performed in 31 patients (22%). Patients who received speech, dental/orthodontic, or psychology intervention followed up longer than those who did not (9.8 vs 2.1 years, P < .001). CONCLUSION: Half of the patients terminated team follow-up by age 7, suggesting that burden of care outweighed perceived benefits of continued follow-up for many families. These results can be used to adjust protocols for children with isolated cleft palate.

Dissemination and Implementation Science in Plastic and Reconstructive Surgery: Perfecting, Protecting, and Promoting the Innovation That Defines Our Specialty.

SUMMARY: Plastic and reconstructive surgery has an illustrious history of innovation. The advancement, if not the survival, of the specialty depends on the continual development and improvement of procedures, practices, and technologies. It follows that the safe adoption of innovation into clinical practice is also paramount. Traditionally, adoption has relied on the diffusion of new knowledge, which is a consistent but slow and passive process. The emerging field of dissemination and implementation science promises to expedite the spread and adoption of evidence-based interventions into clinical practice. The field is increasingly recognized as an important function of academia and is a growing priority for major health-related funding institutions. The authors discuss the contemporary challenges of the safe implementation and dissemination of new innovations in plastic and reconstructive surgery, and call on their colleagues to engage in this growing field of dissemination and implementation science.

E-wave asymmetry elucidates diastolic ventricular stiffness-relaxation coupling: model-based prediction with in vivo validation.

Load, chamber stiffness, and relaxation are the three established determinants of global diastolic function (DF). Coupling of systolic stiffness and isovolumic relaxation has been hypothesized; however, diastolic stiffness-relaxation coupling (DSRC) remains unknown. The parametrized diastolic filling (PDF) formalism, a validated DF model incorporates DSRC. PDF model-predicted DSRC was validated by analysis of 159 Doppler E-waves from a published data set (22 healthy volunteers undergoing bicycle exercise). E-waves at varying (46-120 bpm) heart rates (HR) demonstrated variation in acceleration time (AT), deceleration time (DT), and E-wave peak velocity. AT, DT, and Epeak were converted into PDF parameters: stiffness ([Formula: see text]), relaxation ([Formula: see text]), and load (xo) using published numerical methods. Univariate linear regression showed that over a twofold increase in HR, AT, and DT decrease ([Formula: see text] = -0.44; P < 0.001 and r = -0.42; P < 0.001, respectively), while, DT/AT remains constant (r = -0.04; P = 0.67). Similarly, [Formula: see text] increases with HR (r = 0.55; P < 0.001), while [Formula: see text] has no significant correlation with HR (r = 0.08; P = 0.32). However, the dimensionless DSRC parameter ψ = c2/4k shows no significant correlation with HR (r = -0.03; P = 0.7). Furthermore, ψ is uniquely determined by DT/AT rather than AT or DT independently. Constancy of ψ in spite of a twofold increase in HR establishes that stiffness (k) and relaxation (c) are coupled and manifest via a HR-invariant parameter of E-wave asymmetry and should not be considered independent of each other. The manifestation of DSRC through E-wave asymmetry via ψ underscores the value of DT/AT as a physiological, mechanism-derived index of DF.NEW & NOTEWORTHY: Although diastolic stiffness and relaxation are considered independent chamber properties, the cardio-hemic inertial oscillation that generates E-waves obeys Newton's law. E-waves vary with heart rate requiring simultaneous change in stiffness and relaxation. By retrospective analysis of human heart-rate varying transmitral Doppler-data, we show that diastolic stiffness and relaxation are coupled and that the coupling manifests through E-wave asymmetry, quantified through a parametrized diastolic filling model-derived dimensionless parameter, which only depends on deceleration time and acceleration time, readily obtainable via standard echocardiography.

Video-based Learning in Surgery: Establishing Surgeon Engagement and Utilization of Variable-duration Videos.

OBJECTIVE: To measure surgeon engagement and preferred video duration in a video-based learning program for nerve surgery. BACKGROUND: Educational videos can improve, standardize, and democratize best practices in surgery. To improve care internationally, educators must optimize their videos for learning. However, surgeon engagement and optimal video duration remain undefined. METHODS: A YouTube channel and a video-based learning website, PASSIO Education (passioeducation.com), were examined from 2011 to 2017. We assessed views, geographic location, audience engagement (average percent of video watched), audience retention (percent of viewers at each timepoint), and usage of short (median 7.4, range 4.1-20.3 min) and long (median 17.2, range 6.1-47.7 min) video formats for the same procedures. A survey of PASSIO Education membership examined preferred video duration. RESULTS: Our 117 nerve surgery videos attained over 3 million views with 69% originating outside of the United States. While YouTube achieved more international exposure, PASSIO Education attained a greater mean engagement of 48.4% (14.3% absolute increase, P < 0.0001). Surveyed surgeons (n = 304) preferred longer videos when preparing for infrequent or difficult cases compared with routine cases (P < 0.0001). Engagement declined with video duration, but audience retention between short and long video formats was correlated (τB = 0.52, P < 0.0001). CONCLUSIONS: For effective spread of best practices, we propose the joint use of YouTube for audience outreach and a surgeon-focused platform to maximize educational value. Optimal video duration is surgeon- and case-dependent and can be addressed through offering multiple video durations and interactive viewing options.

Reconstruction of Severe Palm Injury with Sensate Medial Plantar Artery Flap and Nerve Grafting.

A 28-year-old, healthy man presented with an abrasion injury of the left palm, including a full-thickness glabrous skin defect, an open injury of the carpal tunnel with 50% transection of the median nerve, and a multilevel traction/avulsion injury of the thenar motor branch. He underwent repair with a free medial plantar artery flap, nerve transfer of the palmar cutaneous nerve to the medial plantar cutaneous nerve, grafting of the median nerve, and direct neurotization of the thenar muscles via an end-to-side nerve graft from the median nerve. At 8 months postoperative, both donor and recipient areas had healed completely, and the patient had regained meaningful 2-point discrimination of the palm and fingers, achieved innervation of the thenar muscles, and returned to work as a cook.

The Effect of Surgical Video on Resident Performance of Carpal Tunnel Release: A Cadaveric Simulation-Based, Prospective, Randomized, Blinded Pilot Study.

BACKGROUND: Surgical videos are increasingly common, although their role in residency curricula remains unclear. The aim of this study was to evaluate the impact of an educational surgical video on resident performance of an open carpal tunnel release through an Objective Structured Assessment of Technical Skills and serial questionnaires. METHODS: Twenty-two residents representing six postgraduate years were randomized to receive text-based materials with or without a surgical video before performing a carpal tunnel release on human cadavers. Procedures were video recorded, anonymized, and independently evaluated by three hand surgeons using the Objective Structured Assessment of Technical Skills global rating scale, a procedure-specific technical rating scale, a record of operative errors, and pass/fail designation. Residents completed questionnaires before and after the procedure to track confidence in their technical skills. RESULTS: Residents in their first and second postgraduate years (n = 10) who watched the surgical video committed fewer operative errors (median, 4 versus 1.3; p = 0.043) and were more confident in their abilities following the procedure (median, 75 versus 32; p = 0.043) than those receiving text resources alone. There were no significant differences in Objective Structured Assessment of Technical Skills performance or questionnaire responses among more senior residents (n = 12). The technical rating scale was internally consistent (Cronbach α = 0.95; 95 percent CI, 0.91 to 0.98), reliable (intraclass correlation coefficient, 0.73; 95 percent CI, 0.40 to 0.88), and correlated with surgical experience (Spearman ρ = 0.57; p = 0.006). CONCLUSION: Watching an educational surgical video to prepare for a cadaveric procedure significantly reduced operative errors and improved confidence among junior trainees performing a carpal tunnel release.

Alternative diastolic function models of ventricular longitudinal filling velocity are mathematically identical.

The spatiotemporal features of normal in vivo cardiac motion are well established. Longitudinal velocity has become a focus of diastolic function (DF) characterization, particularly the tissue Doppler e'-wave, manifesting in early diastole when the left ventricle (LV) is a mechanical suction pump (dP/dV < 0). To characterize DF and elucidate mechanistic features, several models have been proposed and have been previously compared algebraically, numerically, and in their ability to fit physiological velocity data. We analyze two previously noncompared models of early rapid-filling lengthening velocity (Doppler e'-wave): parametrized diastolic filling (PDF) and force balance model (FBM). Our initial numerical experiments sampled FBM-generated e'(t) contours as input to determine PDF model predicted fit. The resulting exact numerical agreement [standard error of regression (SER) = 9.06 × 10-16] was not anticipated. Therefore, we analyzed all published FBM-generated e'(t) contours and observed identical agreement. We re-expressed FBM's algebraic expressions for e'(t) and observed for the first time that model-based predictions for lengthening velocity by the FBM and the PDF model are mathematically identical: e'(t) = γe-αtsinh(ßt), thereby providing exact algebraic relations between the three PDF parameters and the six FBM parameters. Previous pioneering experiments have independently established the unique determinants of e'(t) to be LV relaxation, restoring forces (stiffness), and load. In light of the exact intermodel agreement, we conclude that the three PDF parameters, relaxation, stiffness (restoring forces), and load, are unique determinants of DF and e'(t). Thus, we show that only the PDF formalism can compute the three unique, independent, physiological determinants of long-axis LV myocardial velocity from e'(t).NEW & NOTEWORTHY We show that two separate, independently derived physiological (kinematic) models predict mathematically identical expressions for LV-lengthening velocity (Doppler e'-wave), indicating that damped harmonic oscillatory motion is a physiologically accurate model of diastolic function. Although both models predict the same "overdamped" velocity contour, only one model solves the "inverse problem" and generates unique, lumped parameters of relaxation, stiffness (restoring force), and load from the e'-wave.

Evaluation of Multidisciplinary Team Clinic for Patients With Isolated Cleft Lip.

OBJECTIVE: To report the incidences of secondary lip and nose operations, otolaryngology procedures, speech-language therapy, neurodevelopmental concerns, and dental and orthodontic issues in children with isolated cleft lip to inform multidisciplinary cleft team protocols. SETTING: An American Cleft Palate-Craniofacial Association-approved team at a tertiary academic children's hospital. DESIGN: Retrospective cohort study of patients evaluated through longitudinal clinic visits by a multidisciplinary cleft palate and craniofacial team between January 2000 and June 2018. PATIENTS, PARTICIPANTS: Children with nonsyndromic cleft lip with or without cleft alveolus (n = 92). RESULTS: Median age at final team visit was 4.9 years (interquartile range: 2.4-8.2 years). Secondary plastic surgery procedures were most common between ages 3 and 5 (135 per 1000 person-years), and the majority of these procedures were minor lip revisions. The rate of tympanostomy tube insertion was highest before age 3 (122 per 1000 person-years). By their final team visit, 88% of patients had normal hearing and 11% had only slight to mild conductive hearing loss. No patients had speech errors attributable to lip abnormalities. Psychological interventions, learning disabilities, and dental or orthodontic concerns were uncommon. CONCLUSIONS: Most patients with isolated cleft lip may not require long-term, longitudinal evaluation by cleft team specialists. Cleft teams should develop limited follow-up protocols for these children to improve resource allocation and promote value-based care in this patient population.

Quantifying Diastolic Function: From E-Waves as Triangles to Physiologic Contours via the 'Geometric Method'.

Conventional echocardiographic diastolic function (DF) assessment approximates transmitral flow velocity contours (Doppler E-waves) as triangles, with peak (Epeak), acceleration time (AT), and deceleration time (DT) as indexes. These metrics have limited value because they are unable to characterize the underlying physiology. The parametrized diastolic filling (PDF) formalism provides a physiologic, kinematic mechanism based characterization of DF by extracting chamber stiffness (k), relaxation (c), and load (x o ) from E-wave contours. We derive the mathematical relationship between the PDF parameters and Epeak, AT, DT and thereby introduce the geometric method (GM) that computes the PDF parameters using Epeak, AT, and DT as input. Numerical experiments validated GM by analysis of 208 E-waves from 31 datasets spanning the full range of clinical diastolic function. GM yielded indistinguishable average parameter values per subject vs. the gold-standard PDF method (k: R2 = 0.94, c: R2 = 0.95, x o : R2 = 0.95, p < 0.01 all parameters). Additionally, inter-rater reliability for GM-determined parameters was excellent (k: ICC = 0.956 c: ICC = 0.944, x o : ICC = 0.993). Results indicate that E-wave symmetry (AT/DT) may comprise a new index of DF. By employing indexes (Epeak, AT, DT) that are already in standard clinical use the GM capitalizes on the power of the PDF method to quantify DF in terms of physiologic chamber properties.

Engaging and disengaging recurrent inhibition coincides with sensing and unsensing of a sensory stimulus.

Even simple sensory stimuli evoke neural responses that are dynamic and complex. Are the temporally patterned neural activities important for controlling the behavioral output? Here, we investigated this issue. Our results reveal that in the insect antennal lobe, due to circuit interactions, distinct neural ensembles are activated during and immediately following the termination of every odorant. Such non-overlapping response patterns are not observed even when the stimulus intensity or identities were changed. In addition, we find that ON and OFF ensemble neural activities differ in their ability to recruit recurrent inhibition, entrain field-potential oscillations and more importantly in their relevance to behaviour (initiate versus reset conditioned responses). Notably, we find that a strikingly similar strategy is also used for encoding sound onsets and offsets in the marmoset auditory cortex. In sum, our results suggest a general approach where recurrent inhibition is associated with stimulus 'recognition' and 'derecognition'.

Behavioural correlates of combinatorial versus temporal features of odour codes.

Most sensory stimuli evoke spiking responses that are distributed across neurons and are temporally structured. Whether the temporal structure of ensemble activity is modulated to facilitate different neural computations is not known. Here, we investigated this issue in the insect olfactory system. We found that an odourant can generate synchronous or asynchronous spiking activity across a neural ensemble in the antennal lobe circuit depending on its relative novelty with respect to a preceding stimulus. Regardless of variations in temporal spiking patterns, the activated combinations of neurons robustly represented stimulus identity. Consistent with this interpretation, locusts reliably recognized both solitary and sequential introductions of trained odourants in a quantitative behavioural assay. However, predictable behavioural responses across locusts were observed only to novel stimuli that evoked synchronized spiking patterns across neural ensembles. Hence, our results indicate that the combinatorial ensemble response encodes for stimulus identity, whereas the temporal structure of the ensemble response selectively emphasizes novel stimuli.