Longitudinal Cognitive and Neurobehavioral Functional Outcomes Before and After Repairing Otic Capsule Dehiscence

Abstract

Objective:Patients with peripheral vestibular dysfunction because of gravitational receptor asymmetries display signs of cognitive dysfunction and are assumed to have neurobehavioral sequelae. This was tested with pre- and postoperatively quantitative measurements in three cohort groups with superior semicircular canal dehiscence syndrome (SSCDS) symptoms with: 1) superior canal dehiscence (SCD) repaired via a middle cranial fossa craniotomy and canal plugging only; 2) otic capsule defects not visualized with imaging (no-iOCD) repaired with round window reinforcement (RWR) only; or 3) both SCD plugging and subsequent development of no-iOCD followed by RWR.Study Design:Prospective patient series.Setting:Tertiary referral center.Patients:There were 13 adult and 4 pediatric patients with SSCDS who had completion of neuropsychology test batteries pre- and every 3 months postoperatively. Eight patients had no-iOCD and RWR exclusively, 5 had SCD and plugging exclusively, and 4 had both SCD plugging and then development of no-iOCD with RWR. These cohorts included SSCDS with 2 different dehiscence locations.Interventions:Completion of a neuropsychology test battery preoperatively and at 3, 6, 9, and 12 months postoperatively that included: Beck Depression Inventory-II (BDI); Wide Range Intelligence Test (WRIT FSIQ) including average verbal (crystallized intelligence) and visual (fluid intelligence); Wide Range Assessment of Memory and Learning (WRAML), including the four domains of verbal memory, visual memory, attention/concentration, and working memory; and Delis–Kaplan Executive Function System (D-KEFS). The Dizziness Handicap Inventory (DHI) and the Headache Impact Test (HIT-6) were also completed to assess the impact of their disease on activities pre- and postoperatively.Main Outcome Measures:Quantitative and statistical analysis of their cognitive and neurobehavioral function.Results:The pattern of differences between the SCD group and the no-iOCD group from WRAML verbal, visual, and attention test performance indicate different postoperative clinical trajectories. For the WRAML, there was a statistically significant improvement for visual memory and verbal memory for the no-iOCD only and both (SCD and subsequent no-iOCD) groups, but no mean improvement for the SCD only group. By contrast, the no-iOCD group had significantly lower scores on the WRAML attention test preoperatively, but they recovered postoperatively to match the other groups. The preoperative findings and postoperative outcomes did not differ significantly among patient groups on the WRAML working memory test, D-KEFS motor scores, D-KEFS number and letter scores, or Wide Range Intelligence Test scores. There was a significant decrease in the BDI for all groups. The IQ scores were unchanged. There was a statistically significant improvement in the DHI and HIT-6 scores postoperatively in all groups.Conclusions:There was a marked overall improvement in cognitive and neurobehavioral function postoperatively. Variability may result from duration of unde...

Comorbidities confounding the outcomes of surgery for third window syndrome: Outlier analysis

“…One possible explanation of these findings is that in 14 (61%) of these patients, they also had CT‐ TWS. We have suggested that the modiolus may be one site for a CT‐ TWS, and Ilmari Pyykkö's demonstration that intratympanic injection of gadolinium subsequently fills the perilymphatic space in humans and then exits the inner ear via the modiolus and into the internal auditory canal supports this possibility (personal communication, Dr. Ilmari Pyykkö, March 4, 2017). Manzari and Scagnelli reported a patient with bilateral SSCD and bilateral dehiscent modiolus experiencing bilateral TWS; however, the patient was lost to follow‐up before surgical intervention …”

“…Clinicians managing patients with peripheral vestibular disorders are challenged with signs and symptoms of altered cognitive function, which often introduce difficulties when trying to elicit a cogent history. Cognitive alterations appear to be associated with many vestibular asymmetries and in particular with otic capsule defects (third window syndrome [TWS]) . A quarter century ago, Black et al reported that the majority of patients with perilymph fistula (PLF) experience altered cognitive status .…”

“…We reported a prospective cohort of 12 patients with long‐term follow‐up and with SSCDS, 6 with radiographic evidence (CT+ TWS) of SSCD treated with a middle fossa approach and plugging; and 6 with a CT‐ TWS (no imaging visible otic capsule dehiscence) treated with round window reinforcement (RWR) . In our 2 publications related to this topic, we included data showing that CT‐ TWS is also associated with a pseudoconductive hearing loss and abnormal cVEMP findings of reduced threshold and increased amplitude . Dennis Poe's group included reporting 4 cases of CT‐ TWS among their series of CT+ SSCD who had also had abnormally low cVEMP thresholds .…”

Round window plugging in the treatment of superior semicircular canal dehiscence

“…The disorder is characterized by symptoms of autophony, aural fullness, conductive hyperacusis, and noise‐ and/or pressure‐induced vertigo . In addition to these symptoms, patients can also experience migraine headaches, migraine variants, depression, and cognitive dysfunction . Vestibular and audiometric characteristics can include Tullio's phenomenon, Hennebert's sign, valsalva‐induced vertigo/nystagmus, decreased vestibular evoked myogenic potential (VEMP) thresholds and audiometric findings of an air‐bone gap and/or suprathreshold bone scores .…”

Risk of progressive hearing loss in untreated superior semicircular canal dehiscence

“…Vestibular symptoms include sound‐ or pressure‐induced vertigo or chronic imbalance and constitute the presenting complaints of most patients . In addition, recent work has demonstrated the impact of otic capsule dehiscence on mood, memory, and learning . The diagnosis of SSCD is typically confirmed with vestibular testing demonstrating lowered cervical vestibular evoked myogenic potential (VEMP) thresholds or elevated ocular VEMP amplitudes, in addition to imaging evidence of a breach in the bony covering of the SSC…”