Christopher J. Danner

Facial nerve paralysis.

Emotions are communicated through facial expression. Happiness, confusion, and frustration can be expressed with a slight smile, eyebrow shift, or wrinkled nose. Injury to the facial nerve and subsequent inability of perform volitional mimetic movement can provoke anxiety. This article explores the causes, treatment, and prevention of facial nerve paralysis.

A comparison of direct eighth nerve monitoring and auditory brainstem response in hearing preservation surgery for vestibular schwannoma.

Objective: The objective of this study was to compare the effectiveness of direct eighth nerve monitoring (DENM) and auditory brainstem response (ABR) in facilitating hearing preservation during vestibular schwannoma resection. Study Design: This was a retrospective study. Setting: Tertiary referral center. Methods: We conducted a retrospective clinical study of the use of ABR and DENM during vestibular schwannoma removal. Tumors were removed through a retrosigmoid craniotomy. The rate of hearing preservation between the two monitoring modalities was compared. The additional outcome measures of facial nerve function and cerebral spinal fluid leak rate were also evaluated. Results: Hearing preservation was attempted in 77 patients with vestibular schwannomas. Tumor sizes ranged from 0.5 cm to 2.5 cm. Hearing was preserved in 71% of patients with tumors 1 cm or less and in 32% of patients with tumors between 1 and 2.5 cm when direct eighth nerve monitoring was used. Hearing preservation rates with ABR for tumors 1 cm or less were 41% and 10% in patients with tumors between 1 and 2.5 cm (p = 0.03) Facial nerve preservations rates were 94% (House-Brackmann 1–2) for tumors less than 2 cm. Conclusions: DENM provides significantly higher rates of hearing preservation during vestibular schwannoma resection when compared with ABR.

The use of porous polyethylene implants to correct nasal valve collapse.

Objective To evaluate the long-term outcome of correction of nasal valve collapse with a porous polyethylene implant. Study Design and Setting Retrospective review from November 1999 to December 2005. Nasal valve collapse was corrected with a porous polyethylene implant in 12 adults. Main outcome measures included relief of nasal obstruction and complications. Independent variables included other causes of nasal obstruction and need for revision surgery. Simple statistical analysis was performed. Results Median follow-up was 5.6 years (58 months). 75% had complete resolution of nasal obstruction. 100% had complete resolution of nasal obstruction at 6 months and had coexisting causes of nasal obstruction. The implant extrusion rate was 21%. 42% went on to have revision surgery. Conclusion Correction of nasal valve collapse with a porous polyethylene implant provided good long-term symptomatic relief of nasal obstruction, but with significant incidence of infection, implant extrusion, and need for revision surgery. The use of this implant should be reserved for cases in which autogenous graft material is not available.

Extended middle fossa approach to the petroclival junction and anterior cerebellopontine angle.

Objectives: This article seeks to demonstrate the use of the extended middle cranial fossa approach in the treatment of tumors arising in the anterior cerebellopontine angle and petroclival region. Study Design: We conducted a retrospective chart review. Setting: Tertiary referral center. Patients: Ten-year retrospective chart review of over 800 skull base surgical cases demonstrated 16 cases in which the senior author used the extended middle cranial fossa as the sole approach to access the posterior cranial fossa, petroclival junction, or the anterior cerebellopontine angle. There were five males and 11 females, 13 meningiomas, 2 trigeminal schwannomas, and 1 brainstem glioma. Presenting symptoms were dependent on extent of brainstem compression and involvement of surrounding cranial nerves. The symptoms are broken down as follows: hydrocephalus, one; balance disturbance, three; diplopia, five; trigeminal neuralgia, two; hemifacial numbness, one; seizures, one; expressive aphasia, one; and hearing loss, two. Results: Of the 16 patients in this study, one patient needed postoperative care in a skilled nursing facility. Postoperative facial nerve weakness was not experienced in any patient. One patient developed a transient cerebrospinal fluid leak that resolved spontaneously. One patient developed a pseudomeningocele secondary to postoperative hydrocephalus. This was corrected with wound exploration and placement of a ventricular peritoneal shunt. Hearing was not maintained in one patient. Two patients developed new fourth nerve paresis and two patients developed new sixth nerve palsies. There were no postoperative infections and no deaths. Conclusions: The extended middle cranial fossa approach provides excellent access and exposure to tumors in the anterior cerebellopontine angle and petroclival junction. The approach allows more direct access to the area anterior to the internal auditory canal. The key to the approach is adequate bone removal of the petrous apex to provide exposure down to the inferior petrosal sinus and anteriorly to Meckels cave and the petroclival junction. Extradural elevation of the temporal lobe with suitable brain relaxation minimizes postoperative complications.

Atrial natriuretic peptide receptor upregulation in the rat inner ear

The purpose of this study was to further examine whether fluid homeostasis in the endolymphatic system could be regulated by a locally effective paracrine system involving atrial natriuretic peptides (ANPs) and their receptors. We assessed the biologic activity of the 3 ANP receptors (ANP-A, ANP-B, ANP-C) in the rat inner ear by measuring receptor upregulation after inner ear administration of ANPs. After appropriate anesthesia, female Lewis rats were injected with ANP via the round window. The animals were sacrificed 24 hours later, and RNA was isolated for reverse transcription–polymerase chain reaction (RT-PCR). Electrophoresis of RT-PCR products showed the presence of all 3 ANP receptor genes in both injected and control animals. Gene expression was significantly higher 24 hours after injection. These findings demonstrate that ANP receptors in the inner ear can be upregulated after injection of ANPs.

Comparison of retrosigmoid and middle fossa approaches for vestibular schwannoma

Abstract Problem: Hearing preservation during acoustic tumor removal is generally attempted using 1 of 2 approaches: the middle fossa or retrosigmoid. This study evaluates hearing and facial nerve preservation rates using the retrosigmoid approach and compares the postoperative results with those reported in the literature using the middle fossa technique. This comparison was conducted to determine which approach offers an opportunity for the best patient outcome. Methods: Hearing preservation was attempted in 46 patients with vestibular schwannomas. Tumor size ranged from 0.5 to 2.5 cm. A retrosigmoid approach and direct eighth nerve monitoring (DENM) was used for all patients. Outcome measures of hearing preservation, facial nerve function, and cerebral spinal fluid leak were evaluated and compared to those reported using the middle fossa approach. Results: Hearing was preserved in 71% of patients with tumors 1 cm or smaller and 32% of patients with tumors between 1 and 2.5 cm. Facial nerve preservation rates were 94% (HB 1–2) for tumors smaller than 2 cm. Conclusion: The retrosigmoid approach with DENM provides rates of hearing preservation comparable to those reported for the middle fossa approach for the resection of vestibular schwannomas. Facial nerve function, both short-term and long-term, appears to be better with the retrosigmoid approach. Significance: Resection of vestibular schwannomas via either the retrosigmoid approach, the use of DENM, or the middle fossa approach provides comparable results for hearing preservation. However, facial nerve function appears to be better preserved with the retrosigmoid approach. Support: None reported.