Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts - P242

P242
Otolaryngology-Head and Neck Surgery 163(1S)
Presentation schedule is subject to change. The Official Program Abstracts supplement does not reflect changes made after August 10, 2020.
cavity, and 3 canal-wall-up mastoidectomy. Of these 5 were
revisions, 4 of failed craniotomies and 1 of failed canal-wallup mastoidectomy. Bilateral nonsymptomatic SSCD and
intracranial and intratemporal lesions were the indications for
the other 3 obliteration procedures. The hearing of obliterated
ears was rehabilitated with bone-vibrating hearing aids. Other
complications were minor.
Conclusions: Temporal craniotomy is an effective and safe
approach for sealing temporal bone tegmen defects. Some
patients are better served by other approaches, depending on
hearing status, location of defects, and the presence of other
relevant pathologies.

Otology/Neurotology

Posterior Semicircular Canal Dehiscence:
A Case Report and Review of the Literature
Rebecca Grace Brady, MD (Presenter);
Kastley M. Marvin, MD
Objectives: Third-window physiology and its causes are a
well-documented entity within otologic pathologies. However,
it can have a varied clinical presentation and thus may mimic
other otologic problems. Typically, it presents with tinnitus,
autophony, conductive hearing loss, vertigo, nystagmus, and/
or Tullio phenomenon. In addition, dehiscence at varied anatomic locations can cause similar presentations that can further confound the diagnosis. One such location that is unusual
from the commonly attributable superior semicircular canal is
the posterior semicircular canal.
Methods: We report the case of a 38-year-old man with a
2-year history of right-sided aural fullness, sound-induced vertigo, dizziness in response to pressure changes, and nausea.
Results: An audiogram was significant for a mild lowfrequency conductive hearing loss. Ipsilateral and contralateral acoustic reflexes were present bilaterally. Computed
tomography of the temporal bones was remarkable for a posterior semicircular canal fistula consequent to a high-riding
jugular bulb.
Conclusions: Prior reports of posterior semicircular canal
dehiscence (PSCD) in comparison with superior semicircular
canal dehiscence have shown that patients with PSCD have
statistically significant lower air conduction hearing thresholds. Treatment options can include resurfacing, which may
improve the associated vestibular symptoms. Because of its
varied clinical presentation, otolaryngologists should be aware
of the presenting symptoms and have attention to causes of
third-window physiology, including PSCD.
Prediction of Outcome After Cochlear
Implantation Using Machine Learning
Kwang-Hyun Kim (Presenter); Jun-Ho Lee, MD
Objectives: Recently, brain plasticity across modalities during deafness has been reported as being associated with individual outcomes. However, many are from cross-sectional or
case studies, whereas longitudinal observation in multiple
patients is scarce. Therefore, we developed a prediction system using machine learning based on cross-modal plasticity in

a longitudinal study with multiple subjects. We sought to
develop electroencephalography biomarkers for evaluating
and predicting outcomes after cochlear implantation (CI).
Methods: Classification of patients with excellent or good
outcome was based on the features of brain cross-modal plasticity measured using auditory, visual, and tactile event-related
responses and their corresponding electromagnetic sources.
Prediction accuracy, sensitivity/specificity, total error cost,
and training time were compared among conditions and
machine learning estimation model is based on linear supervised training.
Results: Twelve data sets were collected from 4 patients. More
effective classification between excellent and good outcome was
possible with the combined features of sensor-level latency and
sources. Specifically, the tactile feature was found to be a factor
that best explains CI outcome (accuracy 89%, sensitivity 91,
specificity 87, total error cost 2), followed by visual feature
(accuracy 78%, sensitivity 76, specificity 72, error cost 4).
Conclusions: Our results suggest that cross-modal brain
plasticity due to deafness would provide a basis for classifying
the status and prognosis of the CI users. We expect that this
novel method contributes to evaluating and predicting outcomes after cochlear implantation.
Preliminary Pathologic Findings of the
Central Auditory Pathway in Patients With
Chronic Traumatic Encephalopathy
Renata Malimpensa Knoll, MD (Presenter); Raymond Nicks;
Aaron K. Remenschneider, MD, MPH; David H. Jung, MD, PhD;
Victor E. Alvarez; Elliott D. Kozin, MD
Objectives: Chronic traumatic encephalopathy (CTE) is a
neurodegenerative disease associated with repeated exposure
to concussive head trauma. Auditory symptoms have been
anecdotally associated with CTE; however, the precise pathophysiology remains unknown. Herein, we aim to investigate if
neuropathological changes occur along the central auditory
pathway (CAP) in patients with confirmed diagnosis of CTE
postmortem.
Methods: Specimens were obtained from Boston University
Brain Bank. A total of 10 brains from patients with a confirmed neuropathological diagnosis of CTE (5 early stage and
5 late stage) were comprehensively evaluated. Five additional
brains from cognitively intact individuals without history of
mild repetitive head injury were used as age-matched controls. Specimens were assessed for presence of hyperphosphorylated tau (p-tau) deposition and/or neurofibrillary
tangles (NFTs) in the CAP.
Results: Neuropathological changes were found along the
CAP in patients with CTE. Two cases of late-stage CTE (III-IV)
presented with alterations in the auditory cortex, in which 1 had
scattered and the other severe p-tau pathology. One inferior colliculus sample from a brain with early-stage CTE (I-II) revealed
scattered pathology, while 2 samples of the late-stage CTE
(III-IV) showed severe pathology. Control cases had no evidence of p-tau deposition or presence of NFTs in the CAP.

Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts

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