Upper Esophageal Sphincter and Esophageal Motility Pathology on Manometry in Retrograde Cricopharyngeal Dysfunction.

OBJECTIVE: There exists a paucity of data regarding the mechanism and manometric findings in retrograde cricopharyngeal dysfunction (RCPD). In this study, we aimed to compare esophageal physiologic findings between patients with RCPD compared to an asymptomatic cohort. STUDY DESIGN: Case-control study. SETTING: Tertiary Care Center. METHODS: Esophageal high-resolution impedance manometry was completed preoperatively in patients diagnosed with RCPD. Manometric data were compared between the RCPD and asymptomatic cohorts. A 2:1 age-sex-matched asymptomatic cohort was used as the control group. Treatment response was assessed among the RCPD cohort. RESULTS: Thirty-nine patients are included: 13 RCPD [mean age: 31.1 (SD: 12.6) years, female sex: 11 (85%)] and 26 asymptomatic [mean age: 32.1 (SD: 1.5) years, female sex: 22 (85%)]. The RCPD cohort, compared to the asymptomatic cohort, exhibited significantly greater upper esophageal sphincter (UES) length [4.5 (SD: 0.7) vs 3.7 (0.9) cm, P = .01] and higher UES basal pressures [91.9 (35.0) vs 49.7 (25.5) mm Hg, P = .002]. Patients with RCPD demonstrated higher rates of ineffective swallows [70.0% (31.6%) vs 15.4% (21.6%), P < .001] and incomplete bolus clearance [81% (22.0%) vs 21.8% (30.0%), P < .001]. All patients who underwent cricopharyngeal botulinum injections experienced initial improvement of symptoms with 3 patients requiring repeat intervention. CONCLUSION: RCPD is associated with a longer UES, elevated UES basal pressures, and an increased incidence of ineffective esophageal motility. This study is the first to compare preoperative manometry results among patients with RCPD to those of an asymptomatic cohort, providing insights into the mechanism of RCPD.

Trainees Associated with Improved Wait Times and Patient Satisfaction in a Multidisciplinary Clinic.

OBJECTIVE: To determine variables associated with longer wait times and decreased patient satisfaction. To determine the association of trainees with clinic wait times and patient satisfaction scores in an academic center. STUDY DESIGN: Cross-sectional study. METHODS: We recruited 266 study participants from an interdisciplinary Head and Neck Cancer outpatient clinic setting. Trained observers recorded observations related to wait times, time with individual health care practitioners, and total time spent in clinic. An 11-question survey was given to patients at the end of their visit assessing each patient's satisfaction with their visit, subjective wait time, and their likelihood to recommend the health care provider. RESULTS: Increased objective wait times were associated with new patients (p = 0.006) and based on the physician they saw (p < 0.001). Patients who saw a trainee spent less time waiting to see a physician (p = 0.023), more total time with a physician (p = 0.001), and reported higher wait time satisfaction scores (p = 0.001). There was no difference in total visit time if patients saw a trainee (p = 0.42). Patient satisfaction with wait time was correlated with all other aspects of patient satisfaction (p < 0.001). On multivariable analysis, the subjective wait time was associated with the likelihood to recommend (p < 0.001). CONCLUSION: Prolonged objective wait times in a multidisciplinary oncology outpatient setting were associated with several factors including specific physicians and new patient status. Trainee interaction with patients led to shorter wait times and improved patient satisfaction scores with wait times. Satisfaction with wait time was positively correlated with all aspects of patient satisfaction and 'likelihood to recommend' scores. LEVEL OF EVIDENCE: NA Laryngoscope, 134:178-184, 2024.

Lead Time to Recurrence After Posttreatment Plasma and Saliva HPV DNA Testing in Patients With Low-Risk HPV Oropharynx Cancer.

Importance: Head and neck squamous cell carcinoma is a highly lethal cancer that is often associated with human papillomavirus (HPV). Recent studies have shown promise in the use of HPV DNA detection in salivary rinses and plasma as a factor associated with a future diagnosis of HPV-positive oropharynx cancer (HPVOPC). However, the use of plasma and salivary HPV DNA detection in defining risk for recurrence in the context of a prospective, phase 3, clinical trial coupled with standardized clinical surveillance has not been reported. Objective: To identify patients with low-risk HPVOPC at risk for recurrence by detection of HPV16 DNA in plasma and salivary rinses. Design, Setting, and Participants: In this cohort study, 233 low-risk patients were recruited from 32 head and neck treatment centers in Ireland (1 [3.1%]), the Netherlands (1 [3.1%]), and the UK (30 [93.8%]) as part of the DE-ESCALATE HPV trial, an open-label, phase 3 randomized clinical trial examining treatment with cetuximab vs cisplatin for HPVOPC. Patients were assayed for the presence of HPV16 DNA in plasma and salivary rinse via a quantitative polymerase chain reaction-based assay. Main Outcomes and Measures: Assay results were associated with risk of recurrence and lead time from HPV16 DNA detection to recurrence. Results: Of 233 patients, 45 (19.3%) were women, and the mean (SD) age was 57.01 (8.45) years. A total 1040 salivary or blood samples were collected during the course of the study. With a median follow-up of 760 days, the sensitivity and specificity of combined plasma and salivary rinse HPV DNA assays for detecting recurrence were 65% and 87%, respectively. There was a median lead time of positive test to event/recurrence date of 19 days (range, 0-536 days) and mean (SD) of 122 (169.8) days. Conclusion and Relevance: The results of this cohort study suggest that in the setting of a randomized, prospective, phase 3 trial for low-risk patients with HPVOPC, posttreatment presence of HPV DNA in plasma and salivary rinses is associated with recurrence; a lead time between test positivity and clinical recurrence offers a potential opportunity for earlier detection of recurrence.

Tracheal Transection After Prolonged Intubation and Tracheostomy: A Case Report.

Tracheal transection is a rare, life-threatening complication after tracheal injury. Most commonly, tracheal transection presents after blunt trauma, but iatrogenic tracheal transection after tracheotomy has not been well described. Here, we present a case without a history of trauma that presented with signs of symptoms of tracheal stenosis. She was taken to the operating room for tracheal resection and anastomosis and was incidentally found to have a complete tracheal transection intraoperatively.

Wound healing in the vulnerable: A novel case of postauricular wounds caused by mask ties.

Background: The COVID-19 pandemic has made facial masks an essential part of daily life. While protective facial masks are crucial to help the spread of viral infections, they are common causes of facial skin breakdown, acne, and superficial injuries. Masks with elastic ear loops are also particularly likely to cause ear pressure injuries. Case report: Herein, we present a case of a patient experiencing homelessness found to have significant postauricular wounds due to prolonged mask use in the context of the Covid-19 pandemic. These injuries led to bilateral erosion of the helix with partial avulsion of the ear and mask ear loops eroding into cartilage. Why should an emergency physician be aware of this?: We describe a rare complication of mask use and highlight the difficulties the COVID pandemic has made in providing adequate care for chronic head and neck wounds amongst the homeless population. While PPE remains an important part of decreasing the risk of the spread of infections, it is important to recognize the vulnerabilities of the homeless population during the COVID pandemic and how best to care for novel auricular wounds.

Carbon Dioxide Laser Sequestrectomy for Osteoradionecrosis: A Case Series.

Objective: To demonstrate a new approach to sequestrectomy using a carbon dioxide (CO2) laser for a clinic-based technique. Background: Osteoradionecrosis (ORN) of the jaw is a debilitating complication of radiotherapy for head and neck malignancies. Often refractory to medical therapy, surgical intervention for early staged disease with curettage and mechanical bone removal has mixed success, making this disease extremely difficult to treat. Therefore, new approaches to treat ORN of the jaw is needed. Methods: We describe five cases of early-to-intermediate-staged ORN illustrating a novel clinic-based sequestrectomy technique using a CO2 laser. Results: The exposed bone lesions involved the mandibular fixed gingiva, maxillary fixed gingiva, and hard palate. None of the patients had diabetes. Four patients required a total of two laser treatments and one patient needed only one treatment. All five patients demonstrated an excellent response with complete resolution of their ORN-related pain and complete mucosal coverage of the exposed bone with durable results (follow-up range, 7-19 months). Conclusions: This small series demonstrates encouraging results for CO2 laser sequestrectomy for ORN. This novel office-based intervention merits further study in larger prospective series and exploration in other disease populations, such as medication-related osteonecrosis of the jaws.

Virtual Interviewing in the Era of COVID-19: A Preliminary Analysis of Otolaryngology Residency Program Costs.

Objective: A preliminary comparison of the program experience and costs associated with the virtual interview season during the 2020-2021 COVID-19 pandemic against the traditional in-person interview process during the 2019-2020 interview season. Study Design: Cross-sectional survey. Setting: Our institutional program launched an online survey via REDCap to otolaryngology programs across the country. Methods: A 33-item survey was sent to otolaryngology residency program directors regarding their experience and costs associated with virtual interviews during the 2020-2021 cycle and in-person interviews during the previous 2019-2020 cycle. Purchasing cost and opportunity cost were calculated for each program. Results: Twenty-two programs sent back completed survey responses. Program responses were equally represented among all regions of the United States. In the 2020-2021 interview season, programs received more applications (mean, 400 vs 336 the year prior, P < .001) for a similar number of residency spots per program (3.04 in 2020-2021 vs 3.0 2019-2020, P = .715). The virtual interview led to more half-day interviews, a shorter duration of each interview, and fewer interviews completed per interview date. Purchasing cost decreased by $1940.46 (73%), and person-hours dedicated to the interview process decreased by 52.36 with the virtual interview. Total savings per program with virtual interviews were an estimated $6941.66. Conclusions: Virtual interviews in the setting of the COVID-19 pandemic led to a shift in application and interview patterns and was associated with a reduction in costs for programs when compared with the in-person interview format.

Palliative Care, Patient-Reported Measures, and Outcomes in Hospitalized Patients With Cirrhosis.

CONTEXT: Studies of palliative care (PC) in hospitalized patients with cirrhosis have been retrospective, with limited evaluation of patient-reported measures and outcomes. OBJECTIVES: To examine the relationship between PC, patient-reported measures (quality of life and functional status), and outcomes. METHODS: We performed a prospective cohort study of patients with cirrhosis hospitalized from 2014 to 2019. We recorded PC consultation details, quality of life (chronic liver disease questionnaire), and functional status (functional status questionnaire). Patients were followed for 90 days to assess readmissions, costs, and mortality. RESULTS: Seventy-four of 679 patients saw PC, often later in the hospitalization (median hospital day 8; IQR 4-16). Those who saw PC had greater Charlson comorbidity index (mean 6.8 vs. 5.9), MELD (mean 25 vs. 20), and prior 30-day admission (47% vs. 35%). Compared to those who did not see PC, PC patients had greater impairments in intermediate activities of daily living (83% vs. 72%), social activity (72% vs. 59%), quality of interactions (49% vs. 36%), abdominal symptoms (mean score 3.1 vs. 3.6), activity (mean 3.3 vs. 3.6), and overall quality of life (mean 3.6 vs. 3.8). PC was associated with fewer transfusions and upper endoscopies and with greater completion of advanced directives. After multivariable adjustment, PC was not associated with intensive care, 30-day readmissions, 90-day costs, or mortality. CONCLUSION: PC occurs infrequently and late in those with more severe liver disease and functional impairment. PC may be associated with reduction in utilization and greater completion of advanced directives. Randomized trials are needed to evaluate PC for this population.

Neuroanatomic Volume Differences in Tinnitus and Hearing Loss.

OBJECTIVES: To investigate neuroanatomic volume differences in tinnitus and hearing loss. STUDY DESIGN: Cross-sectional. METHODS: Sixteen regions of interest (ROIs) in adults (43 male, 29 female) were examined using 3Tesla structural magnetic resonance imaging in four cohorts: 1) tinnitus with moderate hearing loss (N = 31), 2) moderate hearing loss only (N = 15), 3) tinnitus with normal hearing (N = 17), and 4) normal hearing only (N = 13). ROI volumes were corrected for brain size, age, and sex variations. Analysis of covariance (ANCOVA) and post hoc Tukey's test were used to isolate the effects of tinnitus and hearing loss on volume differences. Effect sizes were calculated as the fraction of total variance (η2 ) in ANCOVA models and percent of mean volume difference relative to mean total volume. RESULTS: The four cohort ANCOVA revealed tinnitus and hearing loss cohorts to have increased volume in the corona radiata (η2  = 0.192; P = .0018) and decreased volume in the nucleus accumbens (η2  = 0.252; P < .0001), caudate nucleus (η2  = 0.188; P = .002), and inferior fronto-occipital fasciculus (η2  = 0.250; P = .0001). Tinnitus with normal hearing showed decreased volume in the nucleus accumbens (22.0%; P = .001) and inferior fronto-occipital fasciculus (18.1%; P = .002), and hearing loss only showed increased volume in the corona radiata (10.7%; P = .01) and decreased volume in the nucleus accumbens (22.1%; P = .001), caudate nucleus (16.1%; P = .004), and inferior fronto-occipital fasciculus (18.3%; P = .003). CONCLUSION: Tinnitus and hearing loss have overlapping effects on neurovolumetric alterations, especially impacting the nucleus accumbens and inferior fronto-occipital fasciculus. Neurovolumetric studies on tinnitus or hearing loss can be more complete by accounting for those two clinical dimensions separately and jointly. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:1863-1868, 2021.

Voice and Stroboscopic Characteristics in Transgender Patients Seeking Gender-Affirming Voice Care.

OBJECTIVE: Understanding transgender voice is in nascent stages. This study describes voice characteristics in treatment-seeking trans women by comparing two validated questionnaires-Voice Handicap Index-10 (VHI-10) and Transsexual Voice Questionnaire (TVQMtF )-and reports incidence of abnormal stroboscopy findings and acoustic characteristics. METHODS: Retrospective review of transgender patients presenting to tertiary-care laryngology center between February 2018-February 2019. Mean VHI-10, TVQ, and Singing VHI-10 (SVHI-10) scores; audio-perceptual grade; acoustic measures; and stroboscopy findings were analyzed. VHI-10 and SVHI-10 vs TVQMtF were compared. RESULTS: Sixty-one trans female patients (mean age: 32 ± 11 years) were analyzed. Mean duration since start of transition was 41.5 ± 61 months. Sixty-nine percent presented full-time female in all contexts. Pathologic stroboscopy findings were found in 5%. Mean questionnaire scores were 16 ± 10 (VHI-10), 19 ± 13 (SVHI-10), and 81 ± 22 (TVQMtF ). Correlation between VHI-10 and SVHI-10 versus TVQMtF was weak, R = 0.47 (P = .053) and R = 0.35 (P = .17), respectively. Mean audio-perceptual grade was 0.27 ± 0.15. Mean Cepstral Spectral Index of Dysphonia (CSID, sustained vowel) was 8.5 ± 21.9. Mean Cepstral Peak Prominence (CPP) Fo and CPP Fo SD in rainbow passage were 157.3 ± 16 and 59.4 ± 15.9, respectively. CONCLUSION: Trans women report perceived voice handicap in speaking and singing, which appears separate from gender-related voice/communication concerns. This study is the first to report stroboscopy findings in transgender individuals, with 5% being abnormal. Stroboscopy is encouraged before initiating voice intervention in transgender patients. Preliminary evaluation suggests weak correlation between VHI-10 or SVHI-10 and TVQMtF but requires further investigation. TVQMtF may provide information which more specifically reflects voice concerns of trans women as compared to VHI-10 and SVHI-10. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1071-1077, 2021.

Bleeding After Elective Interventional Endoscopic Procedures in a Large Cohort of Patients With Cirrhosis.

INTRODUCTION: Elective therapeutic endoscopy is an important component of care of cirrhotic patients, but there are concerns regarding the risk of bleeding. This study examined the incidence, risk factors, and outcomes of bleeding after endoscopic variceal ligation (EVL), colonoscopic polypectomy, and endoscopic retrograde cholangiopancreatography with sphincterotomy in cirrhotic patients. METHODS: A cohort study of patients with cirrhosis who underwent the above procedures at a single center between 2012 and 2014 was performed. Patients with active bleeding at the time of procedure were excluded. Patients were followed for 30 days to assess for postprocedural bleeding and for 90 days for mortality. RESULTS: A total of 1,324 procedures were performed in 857 patients (886 upper endoscopies, 358 colonoscopies, and 80 endoscopic retrograde cholangiopancreatograpies). After EVL, bleeding occurred in 2.8%; after polypectomy, bleeding occurred in 2.0%; and after sphincterotomy, bleeding occurred in 3.8%. Independent predictors of bleeding after EVL and polypectomy included younger age and lower hemoglobin. For EVL, bleeding was also associated with infection and model for end-stage liver disease-Na. International normalized ratio was associated with bleeding in univariate analysis only, and platelet count was not associated with bleeding in any procedure. Bleeding after EVL was associated with 29% 90-day mortality, and bleeding after polypectomy was associated with 14% mortality. Of the 3 patients with postsphincterotomy bleeding, none were outliers regarding their baseline characteristics. DISCUSSION: In patients with cirrhosis, bleeding occurs infrequently after elective therapeutic endoscopy and is associated with younger age, lower hemoglobin, and high mortality. Consideration of these risk factors may guide appropriate timing and preprocedural management to optimize outcomes.

Clinical Features and Outcomes of Pediatric Monophasic and Recurrent Idiopathic Optic Neuritis.

Limited data exist on isolated optic neuritis in children. We report the clinical features and treatment of pediatric subjects with monophasic and recurrent idiopathic optic neuritis. This retrospective cohort study of patients with isolated optic neuritis identified 10 monophasic and 7 recurrent optic neuritis cases. Monophasic optic neuritis patients were older (mean 13.3 ± 4.22) than those with recurrent idiopathic optic neuritis (9.86 ± 3.63). Females represented 50% of monophasic and 85.7% of recurrent idiopathic optic neuritis cases. Patients with monophasic optic neuritis were less likely to have a bilateral onset than recurrent idiopathic optic neuritis (40% vs 57.1%). Only 1 case had oligoclonal bands in the cerebrospinal fluid CSF. Most recurrent idiopathic optic neuritis cases had evidence of anti-myelin oligodendrocyte glycoprotein (MOG) antibodies (5/7). Treatment of recurrent idiopathic optic neuritis cases included intravenous pulse glucocorticosteroids and immunotherapy. We observed differences between recurrent and monophasic idiopathic optic neuritis. Immunosuppression appeared to prevent further relapses in recurrent idiopathic optic neuritis patients. Weaning immunotherapies after several years of quiescence in recurrent idiopathic optic neuritis may be possible, but larger studies are needed.

NSAID therapy for PIK3CA-Altered colorectal, breast, and head and neck cancer.

Epidemiologic evidence indicates that regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) provides a protective effect against the development of colorectal, breast, and head and neck cancers. Genomic characterization of these cancers has lent considerable insight into the subpopulations of cancer patients who are most likely to benefit from NSAID therapy. The PIK3CA gene encodes the catalytic subunit of phosphatidylinositol 3-kinase (PI3K) and is among the most frequently mutated genes in solid tumor malignancies. Cancer-associated mutations in PIK3CA promote signaling via the PI3K pathway and stimulate tumor cell growth. In addition, activation of the PI3K pathway leads to induction of cyclooxygenase-2 (COX-2) enzyme and production of immunosuppressive prostaglandin E2 (PGE2). Notably, in both colorectal cancer and head and neck cancer the subpopulation of patients that benefit from NSAID use is restricted to those whose tumors exhibit PIK3CA genomic alterations. Preclinical studies, particularly in models of head and neck cancer, support the hypothesis that the chemopreventive impact of NSAIDs may be due, in part, to inhibition of COX-2 and reduction of PGE2 levels in the tumor microenvironment.

Sporadic and Von-Hippel Lindau disease-associated spinal hemangioblastomas: institutional experience on their similarities and differences.

INTRODUCTION: Hemangioblastomas are uncommon tumors of the central nervous system that can be seen in Von Hippel-Lindau (VHL) disease. Despite their benign histology, hemangioblastomas can cause substantial morbidity due to involvement of critical structures. In order to better understand the clinical behavior of spinal cord hemangioblastomas, we have analyzed the clinical, pathologic, radiologic characteristics and management of sporadic and VHL-associated cases at our institution. METHODS: We performed a database search to identify all spinal hemangioblastomas at our institution between 1997 and 2016. Tumor characteristics were analyzed for sporadic and VHL-associated tumors separately in order to understand the differences in groups. RESULTS: We included 20 patients with VHL-associated spinal hemangioblastomas, and 22 patients with sporadic spinal hemangioblastomas. VHL-associated patients were significantly younger at time of presentation compared to sporadic patients (p < 0.0025). Thirty-two patients (76.2%) presented with focal weakness, 34 (81.0%) with sensory loss, and 22 (52.4%) with pain. VHL patients were more likely to present with multiple symptoms (p < 0.001). Median follow-up time was 20.9 months, during which 17 tumors recurred. The median recurrence free interval was 44 months. There were no differences in gross total resection rates between sporadic and VHL-associated cases (p = 0.197). VHL-associated cases had a higher rate of repeat surgery for recurrence (14 patients-73.6%) compared to sporadic cases (3 patients-13.6%; p < 0.001). CONCLUSION: VHL-associated spinal hemangioblastomas differ from sporadic tumors in terms of age, presenting symptoms, multifocality, and rate of recurrence. Recurrences seem to be unrelated to the extent of resection, indicating the need for life-long follow up for VHL patients.

Subclinical Saccadic Eye Movement Dysfunction in Pediatric Multiple Sclerosis.

BACKGROUND: Efferent visual dysfunction in children could lead to impaired quality of life at home and school. Eye-tracking can detect subtle efferent dysfunction missed on bedside examination but has not been validated in the pediatric multiple sclerosis population. OBJECTIVE: We sought to determine the feasibility of eye-tracking in children and associations with multiple sclerosis. METHODS: Participants meeting criteria for pediatric multiple sclerosis without acute efferent vision abnormalities and healthy controls were recruited. Multiple sclerosis participants underwent a clinical assessment and saccade and antisaccade testing paradigms. Intraclass correlation coefficients were generated for intertest repeatability. Adjusting for age and intereye correlations, generalized estimating equations compared latencies with case status, Expanded Disability Status Scale and Symbol Digit Modalities Test (SDMT) scores. RESULTS: We eye-tracked 15 children with multiple sclerosis (n = 30 eyes, mean age 15.6 ± 2.1, mean disease duration 3.9 years, median Expanded Disability Status Scale 1.5) compared to 6 healthy controls (n = 12 eyes, age 14.3 ± .95). The intraclass correlation coefficient for repeated trials was 0.85. Adjusting for age, saccadic latency was 60 milliseconds (ms) longer for cases than controls (95% confidence interval = 26.4, 93.8; P = .0005). For antisaccadic latency, we observed a similar trend of 60 ms longer for cases than controls ( P = .06). CONCLUSION: Eye-tracking is a short noninvasive examination, and high intertest repeatability supports use of eye-tracking technology in pediatric multiple sclerosis. Longer saccadic latencies were seen in children with multiple sclerosis despite short disease duration and low Expanded Disability Status Scale scores.

The geometric preference subtype in ASD: identifying a consistent, early-emerging phenomenon through eye tracking.

Background: The wide range of ability and disability in ASD creates a need for tools that parse the phenotypic heterogeneity into meaningful subtypes. Using eye tracking, our past studies revealed that when presented with social and geometric images, a subset of ASD toddlers preferred viewing geometric images, and these toddlers also had greater symptom severity than ASD toddlers with greater social attention. This study tests whether this "GeoPref test" effect would generalize across different social stimuli. Methods: Two hundred and twenty-seven toddlers (76 ASD) watched a 90-s video, the Complex Social GeoPref test, of dynamic geometric images paired with social images of children interacting and moving. Proportion of visual fixation time and number of saccades per second to both images were calculated. To allow for cross-paradigm comparisons, a subset of 126 toddlers also participated in the original GeoPref test. Measures of cognitive and social functioning (MSEL, ADOS, VABS) were collected and related to eye tracking data. To examine utility as a diagnostic indicator to detect ASD toddlers, validation statistics (e.g., sensitivity, specificity, ROC, AUC) were calculated for the Complex Social GeoPref test alone and when combined with the original GeoPref test. Results: ASD toddlers spent a significantly greater amount of time viewing geometric images than any other diagnostic group. Fixation patterns from ASD toddlers who participated in both tests revealed a significant correlation, supporting the idea that these tests identify a phenotypically meaningful ASD subgroup. Combined use of both original and Complex Social GeoPref tests identified a subgroup of about 1 in 3 ASD toddlers from the "GeoPref" subtype (sensitivity 35%, specificity 94%, AUC 0.75.) Replicating our previous studies, more time looking at geometric images was associated with significantly greater ADOS symptom severity. Conclusions: Regardless of the complexity of the social images used (low in the original GeoPref test vs high in the new Complex Social GeoPref test), eye tracking of toddlers can accurately identify a specific ASD "GeoPref" subtype with elevated symptom severity. The GeoPref tests are predictive of ASD at the individual subject level and thus potentially useful for various clinical applications (e.g., early identification, prognosis, or development of subtype-specific treatments).

Biosensing in multiple sclerosis.

INTRODUCTION: The goal of using wearable biosensors in multiple sclerosis (MS) is to provide outcome metrics with higher sensitivity to deficits and better inter-test and inter-rater reliability than standard neurological exam bedside maneuvers. A wearable biosensor not only has the potential to enhance physical exams, but also offers the promise of remote evaluations of the patient either at home or with local non-specialist providers. Areas covered: We performed a structured literature review on the use of wearable biosensors in studies of multiple sclerosis. This included accelerometers, gyroscopes, eye-trackers, grip sensors, and multi-sensors. Expert commentary: Wearable sensors that are sensitive to change in function over time have great potential to serve as outcome metrics in clinical trials. Key features of generalizability are simplicity in the application of the device and delivery of data to the provider. Another important feature to establish is best sampling rate. Having too high of a sampling rate can lead to over-interpretation of noisy data On the other hand, a low sampling rate can result in an insensitive test thus missing subtle changes of clinical interest. Of most importance is to establish metrics derived from wearable devices that provide meaningful data in longitudinal studies.

Excimer formation dynamics of intramolecular pi-stacked perylenediimides probed by single-molecule fluorescence spectroscopy.

Pi-stacked perylenediimides (PDIs) have strong electronic communication between the individual molecules and show great promise as organic electronic materials for applications in field effect transistors, photovoltaics, and liquid crystal displays. To gain further insight into the relationship between conformational behaviors and electronic structures of pi-stacked PDIs, we have investigated changes in the excimer-like state of cofacial PDI oligomers that result from pi-stacking in real time by monitoring the single-molecule fluorescence intensity and lifetime trajectories in a PMMA polymer matrix. The fluorescence intensity and lifetime of pi-stacked perylenediimides are sensitive to the degree of pi-orbital interactions among PDI units, which is strongly associated with molecular conformations in the polymer matrix. Furthermore, our results can be applied to probe the conformational motions of biomolecules such as proteins.