OBJECTIVE: Most of Superior Semicircular Canal Dehiscence (SSCD) are located in the apical region of the SSC. However, in a small number of cases, it may be situated in the medial wall, causing the SSC to contact with the superior petrosal sinus (SPS). The aim of this study is to describe four patients with SSCD involving the superior petrosal sinus (SSCD-SPS) and to perform a review of the literature.
METHODS: Observational retrospective study of patients diagnosed of SSCD-SPS in a tertiary referral center. A systematic review was made, identifying 7 articles in the literature. Clinical presentation, complementary test (pure-tone audiometry, PTA; vestibular evoked myogenic potential, VEMP; computed tomography, CT), therapeutic management and outcomes were reported.
RESULTS: Four new cases of SSCD-SPS are reported, in three of them a transmastoid plugging was performed. 54 patients with SSCD-SPS (57 dehiscences) were reported in the literature. The most frequent symptoms were aural pressure (57.41%) and vertigo provoked by pressure/Valsalva (55.55%). Conductive hearing loss was the most common finding in PTA (47.37%). Abnormally low thresholds were observed in 59.46% of reported VEMP. Transmastoid approach was used in ten cases, middle fossa approach in four, round window reinforcement in one, and occlusion of the SPS using coils in two.
CONCLUSIONS: Within SSCD, we have encountered a rare subtype characterized by its medial wall location in close proximity to the SPS. This subgroup needs special consideration as it has shown its own distinct characteristics. Regarding therapeutic management, we advocate a transmastoid approach.

OBJECTIVE: Radiographic review of pathologies that associate with third window syndrome.
METHODS: Case series and literature review.
RESULTS: Eight unique third window conditions are described and illustrated, including superior, lateral, and posterior semicircular canal dehiscence; carotid-cochlear, facial-cochlear, and internal auditory canal-cochlear dehiscence, labyrinthine erosion from endolymphatic sac tumor, and enlarged vestibular aqueduct.
CONCLUSIONS: The present study highlights the characteristic imaging features and symptoms to differentiate third window pathologies for expedient diagnosis and management planning.

To evaluate patients who become symptomatic from superior semicircular canal dehiscence (SSCD) following head trauma.
Case series assessing patients presenting with SSCD after a trauma.
A case series was completed assessing patients presenting with SSCD after trauma. Data from three academic medical centers were evaluated, including the following: imaging, videonystagmography (VNG)/vestibular evoked myogenic potential (VEMP) testing, audiometric assessment, and surgical repair. Outcome measures included the following: 1) Description of audio-vestibular symptoms, 2) mean pre- and post-operative pure tone average (PTA), word recognition score (WRS), and air bone gap (ABG).
A total of 14 patients were included; 86% were male. Approximately 43% were found to have bilateral SSCD on imaging, with 57% of patients pursuing surgical management. The most common presenting symptoms included pulsatile tinnitus (93%), autophony (79%), and hearing loss (64%). Approximately 36% of patients underwent VNG/VEMP testing, with 83.3% of those demonstrating abnormal results. The mean audiometric findings on the symptomatic side included an air-conduction PTA of 38.0 dB, bone-conduction PTA of 24.3 dB, WRS of 81%, and ABG of 17.9 dB. Among patients who underwent surgery (57%), there was no significant change in the air-conduction PTA, bone-conduction PTA, or WRS (P > .05). However, there was an improvement in the ABG (preoperative = 22.8 dB versus postoperative = 9.7 dB; P = .005).
Head trauma may be a potentiating event for SSCD syndrome. This study advances the hypothesis that these patients likely have underlying radiographic SSCD prior to their trauma, and a traumatic event increases in intra-vestibular or intracranial pressures, unmasking SSCD syndrome.
4 Laryngoscope, 131:E2810-E2818, 2021.

UNASSIGNED: Report a series of cases in which patients have concomitant superior semicircular canal dehiscence (SSCD) and a dehiscent tegmen tympani with Dural contact to the malleus head (DCMH).
UNASSIGNED: An analysis of radiologic and audiologic data in 4 patients who presented with SSCD and DCMH at a tertiary care institution. A pertinent literature review was performed.
UNASSIGNED: Four patients (5 ears) had SSCD and DCMH. In 3 patients with unilateral DCMH, the mean maximum air-bone gap was 15 dB in the ear with DCMH compared to 50 dB in the ear without DCMH. Of the 5 ears with DCMH, the mean air conduction threshold at 250 Hz was 17 dB compared to 42 dB in the 3 ears without DCMH.
UNASSIGNED: We report the findings of DCMH in a series of 4 patients with bilateral SSCD. This limited series suggests that ears with SSCD and DCMH have less of an air-bone gap than would be expected, as 1 would expect an additive effect of DCMH and SSCD on the air-bone gap.

Superior semicircular canal dehiscence (SSCD) is caused by a fistula in the arcuate eminence, creating vestibular and auditory disturbances. We aim to determine the effects of gender and age on symptom prevalence and resolution in patients with SSCD. A Boolean search was conducted through four separate scientific databases. Full-text English articles for SSCD patients, who underwent surgery were included. Demographics and outcomes were extracted. A total of 198 patients were identified, and available for quantitative analysis. Between genders, there were no differences in the prevalence of pre- or post-operative symptomology. Both genders had statistically significant improvement in symptomatology with females experiencing significantly high rates of hearing loss improvement compared to male patients. Compared to their younger cohort, patients over 65 had similar symptom frequencies before and after surgery with similar rates of symptom resolution. SSCD repair is safe and effective for resolving auditory and vestibular symptoms. Gender and age may not be strong predictors of patient presentation or symptom resolution. Gender and age-associated factors may not influence patient outcomes.

Computed tomography scan should be performed as a routine before every stapes surgery, in order to exclude concomitant superior semicircular canal dehiscence, since no other clinical, audiological, or electro-physiological criteria are available to exclude concomitant superior semicircular canal dehiscence in the otosclerotic temporal bone.

Literature describes that on the 25th gestational week the labyrinth is fully formed and with adult size. However, recent studies have shown that the cranial and labyrinth development continues until 3 years of age.
OBJECTIVE: To demonstrate through tomographic study the frequency of semicircular canal dehiscence on nine specimens of stillbirths between 32 and 40 weeks and, through literature review, present another possible etiology for its cause.
METHODS: Tomographic study of the temporal bone of 9 specimens of stillbirths between 32 and 40 weeks.
RESULTS: A frequency of 88.89% of alterations were found in our study, with 44% presenting bilateral alterations and 44% unilateral alteration; 11.11% had no dehiscence.
CONCLUSIONS: The tomographic study showed superior semicircular canal dehiscence (SSCD) in 88% of the specimens studied, protrusion of the superior semicircular canal (SSC) in all fetuses, and an enlarged SSC that may be caused by the expansion process provoked by the subarcuate artery entering the subarcuate canaliculus, leading to SSCD.