Kathryn M. Van Abel

Auditory and vestibular symptoms and chronic subjective dizziness in patients with Ménière's disease, vestibular migraine, and Ménière's disease with concomitant vestibular migraine

Objective To compare presentations of Ménière’s disease (MD), vestibular migraine (VM), and Ménière’s disease plus vestibular migraine (MDVM), with and without comorbid chronic subjective dizziness (CSD). Study Design Retrospective review with diagnosis confirmed by consensus conference of investigators using published criteria for MD, VM, and CSD. Setting Ambulatory, tertiary dizziness clinic. Patients Approximately 147 consecutive patients with diagnoses of MD, VM, or MDVM, with/without comorbid CSD. Interventions Diagnostic consultation. Main Outcome Measures Similarities and differences between diagnostic groups in demographics; symptoms; and results of neurotologic, audiometric, and vestibular laboratory assessments. Results Seventy-six patients had MD, 55 MD alone. Ninety-two patients had VM, 71 VM alone. Twenty-one patients had MDVM, representing about one-quarter of those diagnosed with MD or VM. Clinical features thought to differentiate VM from MD were found in all groups. Twenty-seven patients with VM (38%) had ear complaints (subjective hearing loss, aural pressure, and tinnitus) during episodes of vestibular symptoms and headache, including 10 (37%) with unilateral symptoms. Conversely, 27 patients with MD alone (49%) had headaches with migraine features that did not meet full IHS diagnostic criteria, migrainous symptoms (photophobia, headache with vomiting), or first-degree relative with migraine. Including MDVM patients, 59% (45/76) of all patients with MD had migrainous features. Thirty-two patients had CSD; most (29; 91%) were in the VM group. Conclusion Comorbidity was common between MD and VM, and their symptoms overlapped. More specific diagnostic criteria are needed to differentiate these diseases and address their coexistence. CSD co-occurred with VM but was rarely seen with MD.

Magnetic resonance imaging surveillance following vestibular schwannoma resection.

To describe the incidence, pattern, and course of postoperative enhancement within the operative bed using serial gadolinium‐enhanced magnetic resonance imaging (MRI) following vestibular schwannoma (VS) resection and to identify clinical and radiologic variables associated with recurrence.

Primary inner ear schwannomas: a case series and systematic review of the literature.

To describe the natural history of primary inner ear schwannomas (PIES) and evaluate management outcomes and relationship between PIES location, clinical presentation, and time to diagnosis.

Hearing Preservation Among Patients Undergoing Cochlear Implantation

Introduction Despite successful preservation of low-frequency hearing in patients undergoing cochlear implantation (CI) with shorter electrode lengths, there is still controversy regarding which electrodes maximize hearing preservation (HP). The thin straight electrode array (TSEA) has been suggested as a full cochlear coverage option for HP. However, very little is known regarding its HP potential. Methods A retrospective review was performed at two tertiary academic medical centers, reviewing the electronic records for 52 patients (mean, 58.2 yr; range, 11–85 yr) implanted with the Cochlear Nucleus CI422 Slim Straight (Centennial, CO, USA) electrode array, referred to herein as the thin straight electrode array or TSEA. All patients had a preoperative low-frequency pure-tone average (LFPTA) of 85 dB HL or less. Hearing thresholds were measured at initial activation (t1) and 6 months after activation (t2). HP was assessed by evaluating functional HP using a cutoff level of 85 dB HL PTA. Results At t1, 54% of the subjects had functional hearing; 33% of these subjects had an LFPTA between 71 and 85 dB HL, and 17% had an LFPTA between 56 and 70 dB HL. At t2, 47% of the patients had functional hearing, with 31% having an LFPTA between 71 and 85 dB HL. Discussion Preliminary research suggests that the TSEA has the potential to preserve functional hearing in 54% of patients at t1. However, 22% (n = 6) of the patients who had functional hearing at t1 (n = 28) lost their hearing between t1 and t2. Further studies are needed to evaluate factors that influence HP with the TSEA electrode and determine the speech perception benefits using electric and acoustic hearing over electric alone.

The rise of transoral robotic surgery in the head and neck: emerging applications

The use of robotics in the field of head and neck surgery has provided surgeons with the ability to access anatomic locations that were previously only managed via open techniques. This has resulted in decreased overall morbidity, excellent functional results and the promise of equivalent oncologic outcomes. Transoral robotic surgery (TORS) provides access to the oropharynx, hypopharynx, larynx, oral cavity, parapharyngeal space and skull base vial the oral aperture. Studies reviewing the application of TORS to these subsites have been promising, and for many applications TORS has been accepted as a safe and efficacious option for surgical management. However, despite these promising results, TORS remains a surgical instrument that requires sound surgical skill, clinical judgment and oncologic principles, and should be chosen based on the needs of the individual patient and the comfort of the treating surgeon. In this article, we review the history of TORS, relevant anatomy and provide a review of the literature, highlighting the applications, advantages, functional outcomes and disadvantages of TORS for each anatomic subsite.

Still under the microscope: Can a surgical aptitude test predict otolaryngology resident performance?

Application to otolaryngology–head and neck surgery residency is highly competitive, and the interview process strives to select qualified applicants with a high aptitude for the specialty. Commonly employed criteria for applicant selection have failed to show correlation with proficiency during residency training. We evaluate the correlation between the results of a surgical aptitude test administered to otolaryngology resident applicants and their performance during residency.

Transnasal Odontoid Resection: Is there an Anatomic Explanation for Differing Swallowing Outcomes?

OBJECT Swallowing dysfunction is common following transoral (TO) odontoidectomy. Preliminary experience with newer endoscopic transnasal (TN) approaches suggests that dysphagia may be reduced with this alternative. However, the reasons for this are unclear. The authors hypothesized that the TN approach results in less disruption of the pharyngeal plexus and anatomical structures associated with swallowing. The authors investigate the histological and gross surgical anatomical relationship between pharyngeal plexus innervation of the upper aerodigestive tract and the surgical approaches used (TN and TO). They also review the TN literature to evaluate swallowing outcomes following this approach. METHODS Seven cadaveric specimens were used for histological (n = 3) and gross anatomical (n = 4) examination of the pharyngeal plexus with the TO and TN surgical approaches. Particular attention was given to identifying the location of cranial nerves (CNs) IX and X and the sympathetic chain and their contributions to the pharyngeal plexus. S100 staining was performed to assess for the presence of neural tissue in proximity to the midline, and fiber density counts were performed within 1 cm of midline. The relationship between the pharyngeal plexus, clivus, and upper cervical spine (C1-3) was defined. RESULTS Histological analysis revealed the presence of pharyngeal plexus fibers in the midline and a significant reduction in paramedian fiber density from C-2 to the lower clivus (p < 0.001). None of these paramedian fibers, however, could be visualized with gross inspection or layer-by-layer dissection. Laterally based primary pharyngeal plexus nerves were identified by tracing their origins from CNs IX and X and the sympathetic chain at the skull base and following them to the pharyngeal musculature. In addition, the authors found 15 studies presenting 52 patients undergoing TN odontoidectomy. Of these patients, only 48 had been swallowing preoperatively. When looking only at this population, 83% (40 of 48) were swallowing by Day 3 and 92% (44 of 48) were swallowing by Day 7. CONCLUSIONS Despite the midline approach, both TO and TN approaches may injure a portion of the pharyngeal plexus. By limiting the TN incision to above the palatal plane, the surgeon avoids the high-density neural plexus found in the oropharyngeal wall and limits injury to oropharyngeal musculature involved in swallowing. This may explain the decreased incidence of postoperative dysphagia seen in TN approaches. However, further clinical investigation is warranted.

The anatomically intact but electrically unresponsive facial nerve in vestibular schwannoma surgery.

BACKGROUND Permanent facial nerve (FN) paresis after vestibular schwannoma surgery is distressing to both the patient and surgeon. Intraoperative electrophysiological testing has proven invaluable in reducing the incidence of FN injury and may assist in prognosticating long-term function. OBJECTIVE To report definitive FN outcomes among a cohort of patients with an unevokable but anatomically intact seventh nerve after microsurgical vestibular schwannoma resection. METHODS All patients undergoing vestibular schwannoma surgery between 2000 and 2010 at a single tertiary academic referral center were identified. Intraoperative FN monitoring data and definitive FN outcomes were reviewed, and all patients with an anatomically intact but electrically unresponsive FN were included. RESULTS Eleven patients met the inclusion criteria. The median preoperative and definitive postoperative FN scores were House-Brackmann grades 1 and 3, respectively. The median time to definitive FN recovery was 9.4 months. CONCLUSION These data demonstrate that even among this extreme subset, modern electroprognostic testing strategies are incapable of reliably predicting poor outcomes. Therefore, if FN continuity is maintained, attempts at same-surgery FN repair should not be pursued.

Nodular enhancement within the internal auditory canal following retrosigmoid vestibular schwannoma resection: a unique radiological pattern

OBJECT The authors describe the unique occurrence of nodular enhancement within the fundus of the internal auditory canal (IAC) lateral to the preoperative radiological tumor margin following gross-total vestibular schwannoma (VS) resection. METHODS The nature of the study was a retrospective chart review of records. The authors reviewed the cases of all patients who underwent microsurgical resection of a VS between January 2000 and January 2010 at a single tertiary referral center. Patients with incomplete resection, neurofibromatosis Type 2, and those with fewer than 2 postoperative MR images available for review were excluded. Postsurgical patients with IAC enhancement located lateral to the preoperative imaging-delineated tumor margin were identified. Lesion morphology was characterized on serial MR imaging studies. Clinical follow-up and outcomes were recorded. RESULTS Over the past decade, 350 patients underwent microsurgical VS resection. Of these, 16 patients met study criteria and were found to have postsurgical enhancement in the distal aspect of the IAC lateral to the imaging limits of the preoperative tumor margin on the first postoperative MR imaging study (37.5% women, median age 45 years). Initial MR imaging was performed at a mean of 3.1 months following surgery, and the mean radiological follow-up duration was 39.8 months (range 16.4-101.9 months). None of the 16 patients developed recurrence during the follow-up course. CONCLUSIONS In contrast to previous publications that have reported a high rate of recurrence in cases involving nodular enhancement within the original tumor bed, postoperative enhancement in the IAC lateral to the original tumor margin appears to carry much less risk for tumor recurrence. These findings may be helpful when counseling patients on the recommended frequency of postoperative follow-up imaging.

Delayed Cerebrospinal Fluid Rhinorrhea After Gamma Knife Radiosurgery with or without Preceding Transsphenoidal Resection for Pituitary Pathology

BACKGROUND Skull base cerebrospinal fluid (CSF) leak after gamma knife radiosurgery (GKRS) is a very rare complication. In patients who were treated with both GKRS and transsphenoidal resection (TSR) for pituitary lesions, early CSF leak occurs at a comparable rate with the general TSR population (4%). Delayed CSF leak occurring more than a year after TSR, GKRS, or dual therapy is exceedingly rare. METHODS Retrospective chart review and review of the literature. RESULTS We present 2 cases of delayed CSF leak after GKRS to treat pituitary adenoma. One patient developed CSF rhinorrhea 16 years after GKRS for growth hormone-producing pituitary adenoma. The patient had previously undergone TSR surgery 7 years prior to GKRS without complication. Additionally, a second patient developed high-flow CSF rhinorrhea 2 years after GKRS for a prolactinoma that failed dopamine agonist therapy. Both patients underwent a complicated clinical course after presentation, requiring multiple revisions for definitive CSF leak repair. CONCLUSIONS Delayed CSF leak is a rare but serious complication after GKRS independent of TSR status; urgent repair is the treatment of choice. Based on our experience, these leaks have the potential to be refractory, and we recommend aggressive reconstruction, preferably with a vascularized flap, and potentially supplemented by placement of a lumbar drain and acetazolamide. Current evidence is scant and provides little insight regarding an underlying mechanism, which may include bony destruction by the tumor, delayed radiation necrosis, or a secondary empty sella syndrome.