A 52-year-oldintellectually disabled man who had previously undergone a left canal wall down mastoidectomy with cartilage graft tympanoplasty for cholesteatoma 20 years ago presented with new-onset discharge in the contralateral ear. He did not have any symptoms, particularly recurrent discharge, in the post-operative ear, despite infrequent and irregular clinic follow-up for periodic cleaning of the cavity. Clinical examination of the post-operative ear revealed the presence of retained cerumen which was easily removed. The mastoid cavity was noted to have a healthy skin lining, an intact neotympanum, and a smooth bowl-like appearance with no areas that could not be adequately visualized through the surgically widened external auditory meatus. He underwent computerized tomographic imaging of the temporal bone to evaluate the nature and cause of the new-onset discharge in the contralateral ear. This imaging study provided the opportunity to present and describe key post-operative radiologic features of a symptom-free canal-wall down mastoidectomy with tympanoplasty.

A canal-wall down mastoidectomy is a more extensive type of mastoidectomy which, in addition to the resection of the mastoid cortex, all mastoid air cells and Körner septum, is characterized by the resection of the posterior wall of the external auditory canal and scutum. Among the most common causes of failure following this type of surgery are incomplete removal of tegmental air cells and incomplete lowering of the facial ridge.1These two factors can and should be purposefully assessed in a post-operative imaging study.

Adequacy of bone removal in the epitympanum to address the issue of tegmental air cell disease is evaluated on axial CT images at the level of the malleus head-incus body complex and the proximal portion of the tympanic segment of the facial nerve. (Figure 1) All of the bone lateral to the ossicles, especially that overlying the malleus head and anterior epitympanic recess, should have been surgically removed.

On coronal CT images, this same adequacy is demonstrated by the surgical removal of all bone lateral to the epitympanum, from the scutum to the outer cortex, such that there is a clear line of sight from the external auditory meatus to the epitympanum. This helps ensure that there are no pockets of soft tissue medial to any bony ridges; soft tissue that may represent residual or recurrent disease. (Figure 2)

A 2-month-old baby girl presented with a failed neonatal otoacoustic emission (OAE) hearing screening in the left ear. Combined Auditory Brainstem Response/Auditory Steady-State Response (ABR/ASSR) testing confirmed the presence of a unilateral left moderate to severe hearing loss. No Joint Committee on Infant Hearing (JCIH) risk factors for early childhood hearing loss1 were identified. She subsequently underwent computed tomography (CT) of the temporal bones to determine the presence of any inner ear malformation. No abnormalities of the internal auditory canal, cochlea, semicircular canals and ossicles were noted by the radiologist, and the study was officially reported as a “normal temporal bone CT scan.” Independent review of the CT imaging revealed the presence of a visually apparent disparity in the width of the cochlear nerve canals. (Figure 1) Measurement of the cochlear nerve canal width in the axial plane parallel to the infraorbitomeatal line2 using the length measurement tool in the DICOM imaging software (RadiAnt DICOM Viewer, Version 2024.1, Medixant) indicated a cochlear nerve canal width of 2.18 mm on the right and 1.02 mm on the left. (Figure 2) Applying the suggested cutoff point of 1.2 mm as described by Lin et al.,2 we identified the presence of left cochlear nerve canal stenosis as the etiology of the congenital unilateral hearing loss. The cochlear nerve canal, which has also been referred to as the bony canal for the cochlear nerve (BCNC), cochlear aperture, and cochlear fosette, is the bony transition point between the internal auditory canal and the cochlear modiolus. A relationship between a hypoplastic cochlear nerve canal and congenital sensorineural hearing loss was first suggested by Fatterpekar et al. in 2000.3 Subsequent studies confirmed the association between cochlear nerve canal stenosis and sensorineural hearing loss that ranges from near-normal to profound, with a statistically significant relationship between the degree of hearing loss and the degree of stenosis.4 Various cutoff points to define stenosis of the cochlear nerve canal have been identified in the medical literature. These cutoff points range from 1.2 mm to 1.7 mm when the canal width is measured in the axial plane.2 This particular case demonstrated clear-cut evidence of cochlear nerve canal stenosis, as it satisfied the smallest cutoff criteria (< 1.2 mm) seen in the medical literature. The identification of cochlear nerve canal stenosis as the cause of congenital sensorineural hearing loss is important not only from a diagnostic point, but also from a prognostic perspective. Cochlear nerve deficiency has been noted to be highly prevalent among pediatric patients with cochlear nerve canal stenosis,5 and this has significant negative implications in relation to rehabilitation with external hearing devices and cochlear implants.

A 23-year-old male motorcyclist experienced blunt head trauma with loss of consciousness, headache and vomiting, epistaxis and right otorrhagia after a collision with a motor vehicle. Fractures involving the right parietal and temporal bones, as well as acute subdural and subarachnoid hemorrhage were identified on a cranial and facial CT scan. On independent evaluation of the imaging study, a subtle but distinct fracture line in the skull base involving the petrous carotid canal was identified. (Figure 1) The patient subsequently underwent CT angiography to evaluate for any injury to the internal carotid artery. In this examination, good opacification of the internal carotid arteries and their branches was noted, with no evident aneurysm, arteriovenous malformation or arteriovenous fistula formation. In patients with temporal bone fractures, the most commonly encountered complications are: tympano-ossicular injury causing conductive hearing loss, cochlear or vestibular injury causing sensorineural hearing loss or vertigo, facial nerve trauma causing facial paralysis, and fractures of the tegmen or posterior cranial fossa plate causing cerebrospinal fluid leaks.1 On the other hand, injury to the intratemporal portion of the internal carotid artery has been described as a rare complication and as such may be overlooked.1 However, its potentially devastating and life-threatening sequelae necessitates a purposeful and intentional evaluation for its presence. These sequelae include brain ischemia from arterial dissection or complete vascular occlusion, exsanguinating epistaxis or otorrhagia from carotid pseudoaneurysms, and the formation of carotid-cavernous fistulas.2 The incidence of involvement of the carotid canal in skull base fractures has been reported to be around 24%, with around 11% of this group developing internal carotid artery injuries.3 As such, the presence of fractures involving the petrous carotid canal is an indication for CT or MR angiography to further evaluate the internal carotid artery.
Fracture ; temporal bone ; internal carotid artery

Background: The pandemic forced a shift to online education, which encountered issues such as connectivity issues and lack of interaction. The HTML Package (H5P) is an open source software platform that enables the creation and delivery of asynchronous interactive online learning content with minimal technical and data requirements. There is a need to explore H5P in this context. Objectives: To describe the development of digital learning objects using H5P integrated into a university learning management system and to evaluate students' perception of this in terms of usefulness, integration, impact on learning, and important attributes of the learning object. Methodology: H5P interactive content was created and integrated into the UP Manila LMS and used for the OS212 ORL Module. The 179 second year medical students were then invited to answer a survey regarding their perception of H5P's ease of use, impact on learning outcomes, integration, and key attributes of an LO. Data gathered was analyzed using descriptive statistics. Results: There were 134 respondents and they had a highly positive assessment of the H5P learning objects with regards to all studied parameters. Majority of the students found the H5P content easy to use, appropriate and well integrated, and helpful for learning. Conclusion The H5P platform provides the opportunity for the development of online educational content without the need for advanced technical skills. The high level acceptance of LOs using H5P technology underscores its potential to enrich students' educational experience.
Education, Distance ; Education, Medical ; Surveys and Questionnaires

Objective: This case series aims to describe the diagnosis and management of otosclerosis in a series of Filipino patients encountered in a private, subspecialty otologic clinical practice. In particular, it elucidates the demographics, clinical presentation, diagnostic exam findings, clinical intervention and hearing outcomes. Methods: Study Design : Retrospective review of medical records of a case series. Setting : Subspecialty otologic / neurotologic clinical practice. Participants : Medical records of all patients diagnosed to have otosclerosis based on radiologic evidence of fenestral or retrofenestral otosclerosis and/or confirmed during surgical exploration of the middle ear, during the period 2004-2017. Results: Nine patients with otosclerosis were identified. Most patients presented with bilateral, primarily conductive hearing loss in middle age. However, an adolescent patient was also identified. Most patients were from the component cities of the National Capital Region. However, patients from the Cordillera region and south-central Mindanao were also identified. Radiologic evidence of fenestral or retrofenestral otosclerosis was identified in the majority of patients. However, readings of normal temporal bone CT findings were also seen. Obliterative otosclerosis was identified in one patient. Both objective and subjective evidence of hearing improvement was documented after stapedectomy in patients undergoing surgery. Conclusions This study documents the presence of clinical otosclerosis in a Filipino population. As in other populations, it typically presents in middle age as a bilateral, primarily conductive hearing loss. However, a younger age does not preclude its diagnosis, as juvenile otosclerosis has been identified. The presence of patients in regions of the Philippines other than the National Capital Region implies that it has to be considered even in regional populations without a racial predilection for otosclerosis. The identification of radiologic evidence of fenestral and retrofenestral otosclerosis on CT imaging of the temporal bone makes this is an essential part of the work-up of Filipino patients with conductive hearing loss and normal otologic examinations. Surgical treatment via stapes surgery is an effective and viable option in the management of Filipino patients with otosclerosis. The identification of less common variants such as obliterative otosclerosis indicates the need for specialized surgical equipment and appropriate surgical training in order to successfully deal with these situations.
Otosclerosis ; Hearing Loss, Conductive

A 19-year-old woman presented with an 11-month history of sudden-onset left sided hearing loss accompanied by vertigo and headache. Audiometric testing revealed profound left- sided hearing loss. A contrast-enhanced MRI of the internal auditory canal performed 5 months after symptom onset was interpreted as showing a vascular loop, probably the anterior inferior cerebellar artery, abutting and indenting on the left vestibulocochlear nerve; and a prominent and high-riding left jugular bulb. In this study, the internal auditory canals were assessed to be of normal width, with walls that were smooth and sharply defined. A cerebral CT angiogram subsequently performed did not show any abnormal findings related to the previously identified vascular loop. On the basis of these radiologic findings, the patient was advised surgery by physicians at a tertiary- care institution, presumably to address the identified vascular loop. A second opinion was sought by the patient.
Hearing Loss

A 25-year-old male who was recently diagnosed with chronic myelogenous leukemia developed bilateral tinnitus and hearing loss. The hearing loss progressed rapidly but asymmetrically, with the right ear being subjectively worse than the left. Pneumatoscopy revealed bilaterally intact and mobile tympanic membranes and no visual evidence of middle ear pathology. Audiometry confirmed the presence of a profound hearing loss in the right ear and a moderate sensorineural hearing loss in the left ear. In relation to evaluating the cause of hearing loss, the radiologic interpretation of a contrast-enhanced cranial MRI performed to evaluate other neurological symptoms that predated the hearing loss only stated that the cerebellopontine angle cisterns were unremarkable. No mention was made about the status of the inner ears. When asked to comment on the inner ears in the MR study, the radiologist opined that the cranial MRI did not have the proper fine-cut imaging sequences necessary to evaluate this region adequately, and indicated the need for a dedicated MR study of the temporal bones. An independent review of the DICOM imaging data of the patient’s cranial MRI revealed the presence of three imaging sequences with information pertinent to the evaluation of the inner ears. These sequences are shown below, with a sequential narration of the descriptive imaging findings and their clinical significance that helps to arrive at a conclusive diagnosis.
Hearing Loss, Sensorineural ; Ear, Inner ; Magnetic Resonance Spectroscopy ; Leukemia

A 29-year-old Filipina of Chinese descent presented with progressive bilateral conductive hearing loss of several years’ duration. While working overseas, she consulted with an otolaryngologist and underwent computerized tomographic (CT) imaging of the temporal bone as part of her evaluation. She was informed that no abnormalities were identified in the imaging exam, and she was offered exploratory middle ear surgery with possible stapes surgery. She then sought a second opinion, with the intention of obtaining a more definitive diagnosis prior to any invasive medical intervention. A review of the CT imaging study, with particular emphasis on looking for radiologic evidence of otosclerosis, revealed the presence of a focal region of bone demineralization in the region of the fissula ante fenestram. (Figure 1) This finding is consistent with a diagnosis of fenestral otosclerosis.
Otosclerosis ; Hearing Loss, Conductive ; Filipino

A 27-year-old man undergoes otolaryngologic evaluation for blunt head trauma suffered in a vehicular accident. With regards to the right ear, pertinent otologic findings include an ear canal laceration and a delayed-onset facial nerve paresis. Tuning fork testing reveals an abnormal Rinne test on the right (AC Temporal Bone ; Diagnostic Imaging ; Ear Ossicles

During a discussion on temporal bone imaging, a group of resident trainees in otolaryngology were asked to corroborate the finding of a fracture in set of images that were supposed to be representative of a fracture involving the otic capsule.1(Figure 1) Their comments included the following statements: “The image still does not clearly identify the fracture. It would have been better if the images were set to the optimal bone window configuration...” “The windowing must be of concern as well. The exposure setting for the non-magnified view is different from the magnified ones. One must observe consistent windowing in order to assess the fractures more accurately.” “...the images which demonstrate a closer look on the otic capsule areas are not rendered in the temporal bone window which makes it difficult to assess.” “...aside from lack of standard windowing...”
Tomography, X-Ray Computed ; Temporal Bone Diagnostic ; Imaging Diagnostic Tests ; Routine ; Tomography, X-Ray Computed ;