Diagnostic performance of reformatted isotropic thin-section helical CT images in the detection of superior semicircular canal dehiscence

Sparacia, Gianvincenzo; Iaia, Alberto

doi:10.1177/1971400916689484

Cited by 8 publications

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Currently, multidetector CT (MDCT) is the mainstay of the diagnosis of a semicircular canal dehiscence. The accuracy in the detection of SSCD in one study was between 92.9% utilizing standard axial and coronal planes and 98.8% using planes parallel and perpendicular to the SSC, similar to the technique and imaging planes as used in this study (20). However, Sequeira et al (21) caution that MDCT tends to overestimate the prevalence of SSCD in comparison with higher resolution CT techniques such as microCT.…”

Section: Discussionsupporting

confidence: 58%

Description of a New Labyrinthine Dehiscence: Horizontal Semicircular Canal Dehiscence at the Tympanic Segment of the Facial Nerve

Gianoli

Soileau

Shore³

2022

Front. Neurol.

View full text Add to dashboard Cite

ObjectiveThis report is a case series of patients with findings suspicious for a labyrinthine dehiscence syndrome not previously described in the medical literature. We describe the clinical and test findings in 16 patients with CT findings suspicious for dehiscence of the ampullated end of the horizontal semicircular canal at the tympanic segment of the facial nerve.Study DesignObservational case series.SettingNeurotology vestibular referral center.PatientsTo be included in this study the patients were seen at our center in 2019 and had a high-resolution CT scan with a collimation of 0.6 mm. Patients who were identified as having findings suspicious for dehiscence of bone where the facial nerve crosses the ampullated end of the horizontal semicircular canal (HSC-FND) were identified and further analyzed.InterventionsCase series retrospective record review of patient symptoms, physical findings, audiometry, vestibular testing, and CT scans was performed. CT findings of other dehiscent sites were noted. A comparison to surgically treated perilymph fistula (PLF) patients of the same period was performed.Main Outcome MeasuresHistory and physical exam were reviewed for auditory symptoms, vestibular symptoms, and exacerbating factors. and. Audiometry and vestibular testing were reviewed to determine which tests were most likely to be abnormal. CT scans were independently graded according to degree of suspicion for HSC-FND. Finally, patients with HSC-FND as the sole dehiscence identified were compared to those who had HSC-FND plus other dehiscent sites (HSC-FND+O) and to the group of surgically treated PLF patients.ResultsOf 18 patients, 16 met inclusion criteria. Nine (56%) of those suspicious for HSC-FND had dehiscences in other parts of the labyrinth. Additional dehiscent sites included: six superior semicircular canal dehiscences (SSCD), two cochlear facial dehiscences and one cochlear carotid dehiscence. The most common auditory symptoms were autophony followed by tinnitus and aural fullness. The most common vestibular symptoms were pulsion sensation (feeling of being pushed to one side) followed by vertigo spells. The most common exacerbating factors for vertigo were straining, and sound. The most commonly abnormal vestibular test was nasal Valsalva testing, which was positive in all but one patient. Anamnesis and examination observations were similar in both groups, but the HSC-FND group were less likely to demonstrate a caloric weakness or an abnormal ECOG compared to the HSC-FND+O group. Of note, cVEMP was more often found to have lower thresholds in the HSC-FND group compared to the HSC-FND+O group. An example case is highlighted. Comparison to the PLF patients revealed statistically significant difference in the presenting symptoms of autophony, fullness and pulsion sensation. When comparing testing, HSC-FND patients were more likely to have an abnormal cVEMP and PLF patients were more likely to have asymmetric hearing. The incidence of bilateral disease was also more common among the HSC-FND patients than the PLF patients.ConclusionsA new labyrinthine dehiscence has been described to occur where the tympanic segment of the facial nerve crosses over the ampullated end of the horizontal semicircular canal. HSC-FND patients can present in a similar manner as HSC-FND+O patients with similar test findings except as mentioned above. The identification of one dehiscence such as SSCD does not preclude the presence of another dehiscence such as HSC-FND. HSC-FND could be the source of persistent symptoms post SSCD surgery as illustrated in the case presented. HSC-FND patients seem to identify themselves compared to PLF patients by a much more likely presenting symptoms of autophony, fullness, pulsion, abnormal cVEMP, bilaterality of disease, and symmetric hearing.

show abstract

Section: Discussionsupporting

confidence: 58%

Description of a New Labyrinthine Dehiscence: Horizontal Semicircular Canal Dehiscence at the Tympanic Segment of the Facial Nerve

Gianoli

Soileau

Shore³

2022

Front. Neurol.

View full text Add to dashboard Cite

show abstract

“…These scans were obtained in the axial plane with a 128-row CT scanner (Somatom Definition AS, Siemens, Erlangen, Germany) and a 0.8mm slice thickness. Reformatted images were then obtained from a volumetric isotropic dataset by using a dedicated workstation (Philips, Best, Netherlands) [ 6 ]. Standard axial, coronal and sagittal images were reconstructed at 0.1mm increments.…”

Section: Methodsmentioning

confidence: 99%

Computed Tomography Assessment of the Retrolabyrinthine Approach

Vaz-Guimarães¹,

Cartaxo²,

Fonte³

et al. 2023

Cureus

View full text Add to dashboard Cite

Introduction This study aimed to evaluate preoperative radiological assessments of the retrolabyrinthine approach to identify and describe anatomical constraints that may anticipate a more challenging situation for neurosurgeons and otolaryngologists specialized in skull base surgery. Materials and methods The study included 75 adult patients who underwent high-resolution computed tomography angiography scans of the head, with the aim of analyzing the side of the dominance of the sigmoid sinus (SS), the level of pneumatization of the mastoid portion of the temporal bone, and the height of the jugular bulb. Results The results showed that dominant SS and type 2 jugular bulbs were more common on the right side, while smaller type 1 bulbs were significantly more common on the left. Conclusions These findings provide valuable information for neurosurgeons and otolaryngologists in predicting the difficulty of the retrolabyrinthine approach based on preoperative radiological assessments.

show abstract