Color Dependence Analysis in a CNN-Based Computer-Aided Diagnosis System for Middle and External Ear Diseases

Artificial intelligence-assisted otologic diagnosis has been of growing interest in the scientific community, where middle and external ear disorders are the most frequent diseases in daily ENT practice. There are some efforts focused on reducing medical errors and enhancing physician capabilities using conventional artificial vision systems. However, approaches with multispectral analysis have not yet been addressed. Tissues of the tympanic membrane possess optical properties that define their characteristics in specific light spectra. This work explores color wavelengths dependence in a model that classifies four middle and external ear conditions: normal, chronic otitis media, otitis media with effusion, and earwax plug. The model is constructed under a computer-aided diagnosis system that uses a convolutional neural network architecture. We trained several models using different single-channel images by taking each color wavelength separately. The results showed that a single green channel model achieves the best overall performance in terms of accuracy (92%), sensitivity (85%), specificity (95%), precision (86%), and F1-score (85%). Our findings can be a suitable alternative for artificial intelligence diagnosis systems compared to the 50% of overall misdiagnosis of a non-specialist physician.

The Sleep-Wake Cycle in the Nicotinic Alpha-9 Acetylcholine Receptor Subunit Knock-Out Mice

There is a neural matrix controlling the sleep-wake cycle (SWC) embedded within high ranking integrative mechanisms in the central nervous system. Nicotinic alpha-9 acetylcholine receptor subunit (alpha-9 nAChR) participate in physiological processes occurring in sensory, endocrine and immune systems. There is a relationship between the SWC architecture, body homeostasis and sensory afferents so that disruption of afferent signaling is expected to affect the temporal organization of sleep and wake states. The analysis of the SWC of 9 nAChR knock-out animals may help to reveal the contribution of alpha-9 nAChR to sleep chronobiological determinants. Here we explore the polysomnogram in chronically implanted alpha-9 nAChR knock-out (KO) and wild-type (WT) individuals of the hybrid CBA/Sv129 mouse strain. Records were obtained in isolation chambers under a stable 12:12 light:dark cycle (LD). To unmask the 24-h modulation of the SWC a skeleton photoperiod (SP) protocol was performed. Under LD the daily quota (in %) of wakefulness (W), NREM sleep and REM sleep obtained in KO and WT animals were 45, 48 and 7, and 46, 46 and 8 respectively. Both groups exhibit nocturnal phase preference of W as well as diurnal and unimodal phase preference of NREM and REM sleep. The acrophase mean angles of KO vs. WT genotypes were not different (Zeitgeber Time: 6.5 vs. 14.9 for W, 4.3 vs. 2.8 for NREM sleep and 5.3 vs. 3.4 for REM sleep, respectively). Transference to SP do not affect daily state quotas, phase preferences and acrophases among genotypes. Unmasking phenomena of the SWC such as wake increment during the rest phase under SP was evident only among WT mice suggesting the involvement of retinal structures containing alpha-9 nAChR in masking processes. Furthermore, KO animals exhibit longer NREM and REM sleep episodes that is independent of illumination conditions. Consolidated diurnal NREM sleep contributed to obtain higher values of NREM sleep delta-EEG activity among KO mice during rest phase. In conclusion, circadian and sleep homeostatic aspects of the SWC are operative among alpha-9 nAChR KO animals. We propose that alpha-9 nAChR participate in retinal signaling processes responsible of the positive masking of sleep by light.

How the COVID-19 pandemic affects specialty training: An analysis of a nationwide survey among otolaryngology residents in Chile

Introduction

Coronavirus disease 2019, or COVID-19, has become a global pandemic. Given that the highest viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is found in the airway, otolaryngologists are at high risk of infection. As a result, multiple recommendations have emerged regarding protective measures for surgical teams, including suspending non-urgent procedures and surgeries.

Objectives

To evaluate the impact of the COVID-19 pandemic on otolaryngology residency training programs nationwide.

Methods

A cross-sectional survey-based study was completed in April 2020. The participants were recruited through an online survey, sent by email to all Chilean otolaryngology residents. Demographics, clinical activities, on-call shifts, COVID-19 infection status, exposure to COVID-19 patients, deployment to other specialties, diagnostic/therapeutic procedures, and surgeries performed were analyzed. Self-reported surgical data logs from previous years were used to compare results.

Results

Forty-seven residents completed the survey (84% response rate); 64% of residents refer seeing patients ten days or less during April 2020. Commonly performed procedures such as flexible nasolaryngoscopy, rigid nasal endoscopy, and peritonsillar abscess drainage were not performed by over 40% of the residents in that month. Only 38% participated in surgeries, with an average of 0.6 surgeries as a first surgeon, a dramatic decrease in surgical exposure when comparing the data logs from previous years. Most residents refer the following measures taken by their residency program to improve residency training: bibliographic videoconferences (87%), online clinical case seminars (60%), weekly journal clubs (38%), among others.

Conclusions

Clinical and surgical opportunities decreased dramatically during April 2020. Adjustments to the regular academic curricula should be considered to decrease the negative impact of this pandemic on residency training.

The Strength of the Medial Olivocochlear Reflex in Chinchillas Is Associated With Delayed Response Performance in a Visual Discrimination Task With Vocalizations as Distractors

The ability to perceive the world is not merely a passive process but depends on sensorimotor loops and interactions that guide and actively bias our sensory systems. Understanding which and how cognitive processes participate in this active sensing is still an open question. In this context, the auditory system presents itself as an attractive model for this purpose as it features an efferent control network that projects from the cortex to subcortical nuclei and even to the sensory epithelium itself. This efferent system can regulate the cochlear amplifier sensitivity through medial olivocochlear (MOC) neurons located in the brainstem. The ability to suppress irrelevant sounds during selective attention to visual stimuli is one of the functions that have been attributed to this system. MOC neurons are also directly activated by sounds through a brainstem reflex circuit, a response linked to the ability to suppress auditory stimuli during visual attention. Human studies have suggested that MOC neurons are also recruited by other cognitive functions, such as working memory and predictability. The aim of this research was to explore whether cognitive processes related to delayed responses in a visual discrimination task were associated with MOC function. In this behavioral condition, chinchillas held their responses for more than 2.5 s after visual stimulus offset, with and without auditory distractors, and the accuracy of these responses was correlated with the magnitude of the MOC reflex. We found that the animals’ performance decreased in presence of auditory distractors and that the results observed in MOC reflex could predict this performance. The individual MOC strength correlated with behavioral performance during delayed responses with auditory distractors, but not without them. These results in chinchillas, suggest that MOC neurons are also recruited by other cognitive functions, such as working memory.

[Development of Normative Data for the Mini Mental State Examination (MMSE) in the Elderly Population of Chile: A Multi-City Study]

BACKGROUND

The Mini-Mental State Examination (MMSE) is one of the most widely used tests to assess the global cognitive deterioration of older adults. There are many versions of this Test in Spanish. A validation study was previously conducted in Chile, but to date, no standards computed from a large population sample are available.

AIM

to develop normative scores according to age and educational level for older people living in Chile.

METHOD

Data were collected from a sample of 1199 subjects between 50 and 91 years of age from various research centers.

RESULTS

We present the normative scores in percentiles calculated according to age (50-64, 65-74, 75-91 years of age) and educational level (1-12 years and more than 13 years of formal schooling).

CONCLUSION

This article provides normative scores for the MMSE that should be useful in clinical practice as they may help better interpret the performances of Chilean older adults who seek consultation for cognitive impairment.

Exploring the relationship between frailty and executive dysfunction: the role of frontal white matter hyperintensities

Introduction

Frailty is a geriatric syndrome frequently associated with executive dysfunction and white matter hyperintensities (WMH). But the relation between executive dysfunction and brain changes is poorly understood in frail subjects. Our hypothesis is that frontal-WMH mediates the association between frailty and executive dysfunction.

Methods

A convenience sample of 113 subjects older than 65 years without dementia was studied with neuropsychological test, a structured clinical interview, physical examination and brain MRI. They were classified as robust or pre-frail and frail using the frailty phenotype score (0-5). The frontal WMH (F-WMH) were manually graduated (0-6) using the "Age-Related White Matter Changes score" from FLAIR sequences at a 3 Tesla brain MRI. A mediation analysis was done for testing whether F-WMH could act as a link factor between frailty phenotype score and executive dysfunction.

Results

The group's mean age was 74 ± 6 years, subjects with higher frailty score had more depressive symptoms and worse performance in executive function tests. A regression analysis that explained 52% of the variability in executive functions, revealed a significant direct effect of frailty score (Standardized βcoeff [95% CI] -0.201, [-0.319, -0.049], and F-WMH (-0.152[-0.269, -0.009]) on executive functions, while the F-WMH showed a small partial mediation effect between frailty and executive functions (-0.0395, [-0.09, -0.004]).

Discussion

Frontal matter hyperintensities had a small mediation effect on the association between frailty and executive dysfunction, suggesting that other neuropathological and neurofunctional changes might also be associated with executive dysfunction in frail subjects.