Biomedical subjects

H Alexander Arts

Publications and source records attributed to H Alexander Arts.

9 recordsLinked to original sources

PubMed2006

Transient evoked otoacoustic emissions pattern as a prognostic indicator for hearing preservation in acoustic neuroma surgery.

OBJECTIVE: To determine whether pre-operative transient otoacoustic emission (TEOAE) patterns are predictive of successful hearing preservation in acoustic neuroma surgery. STUDY DESIGN: Retrospective observational study. SETTING: Tertiary referral medical center. PATIENTS: A convenience sample was identified in whom pre-operative TEOAE data were available in patients undergoing acoustic neuroma surgery from 1993-2004. Ninety-three patients were identified who met this inclusion criterion. INTERVENTIONS: Subjects underwent attempted hearing preservation surgery via middle cranial fossa or retrosigmoid approaches. Routine audiometry, ABR, and TEOAE. MAIN OUTCOME MEASURES: Pre- and post-operative pure tone and speech results were categorized into hearing classes A, B, C, and D as described in the American Academy of Otolaryngology guidelines (1995). Hearing preservation was defined by maintenance of the pre-operative hearing class or downgrade to within one hearing class post-op. Pre-operative TEOAE results were divided into five frequency bands and described as positive in each band if there was a response above the noise floor with >50% reproducibility. RESULTS: Hearing was preserved in 51 patients (55%). Of these, 11 (22%) had positive TEOAE response in all five frequency bands measured (1, 1.5, 2, 3, 4 kHz), whereas 40 (78%) had TEOAE responses ranging from 0 to 4 frequency bands. 42 patients failed to preserve their hearing. Of these, only three (7%) had positive TEOAE in all five frequency bands, and 39 (93%) had TEOAE responses ranging from 0 to 4 frequency bands (p<0.05). Other variables of prognostic significance to hearing preservation in our series included smaller tumor size, tumor location within the IAC, better pre-operative hearing, and shorter latencies on ABR. Logistic regression was then used to compare the prognostic value of TEOAE against these variables. In our series, ABR latencies and 5 frequency band response on TEOAE showed the highest significant correlation to hearing preservation (p<0.05). CONCLUSION: A robust pre-operative TEOAE frequency band pattern may be used as a favorable prognostic indicator for potential hearing preservation in acoustic neuroma surgery. The prognostic value may be enhanced when combined with other prognostic factors such as tumor size, tumor location, pre-operative ABR and audiometric results.

Adolescent↗

PubMed2006

Hearing preservation and facial nerve outcomes in vestibular schwannoma surgery: results using the middle cranial fossa approach.

OBJECTIVE: To evaluate surgical results using the middle cranial fossa approach for hearing preservation vestibular schwannoma surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral academic center. PATIENTS: Seventy-three consecutive patients with vestibular schwannoma operated on using the middle cranial fossa approach between February 1999 and February 2005. INTERVENTIONS: The tumors were removed via the middle cranial fossa approach with modifications to improve exposure. Standard auditory brainstem and facial nerve monitoring were used. MAIN OUTCOME MEASURES: Pre- and postoperative hearing measures and facial function, tumor size, and postoperative complications. Hearing status was categorized into Classes A, B, C, and D as described by the American Academy of Otolaryngology-Head and Heck Surgery "Guidelines for the Evaluation of Hearing Preservation in Acoustic Neuroma, 1995." RESULTS: Thirty-four patients presented with Class A hearing preoperatively. Among patients presenting with Class A hearing, a total of 27 (80%) maintained Class A or B hearing postoperatively. Of these, 21 (62%) remained in Class A, 6 (18%) deteriorated slightly to Class B, and 7 (20%) deteriorated to Class D postoperatively. Twenty-eight patients presented with Class B hearing preoperatively. Of these, 18 (64%) remained in Class B, 3 (11%) deteriorated to Class C, and 7 (25%) deteriorated to Class D. Three patients had Class C hearing preoperatively. Of these, 2 (66%) remained in Class C and 1 (33%) deteriorated to Class D. Eight patients presented in Class D and one of these improved to Class C postoperatively. Overall, 62 patients presented with useful (Class A or B) hearing and 45 (73%) remained in Class A or B. Nineteen patients had tumors larger than 10 mm in greatest dimension and had Class A or B hearing preoperatively. Of these, 11 (58%) retained Class A or B hearing postoperatively. At 4 months or greater follow-up, facial nerve outcome were excellent in 96%: House-Brackmann Grade I in 61 (85%), Grade II in 8 (11%), and Grade III in 3 (4%). There were no Grade IV, V, or VI results on final follow-up. Six (8%) patients developed cerebrospinal fluid leaks. CONCLUSION: By achieving excellent exposure and using meticulous microsurgical technique, it is possible to resect small vestibular schwannomas via the middle fossa approach, with preservation of hearing at excellent or preoperative levels in the majority of patients, with excellent or satisfactory facial nerve outcomes in 96% of patients.

Audiometry, Evoked Response↗

PubMed2005

Corticosteroid response and supporting cell antibody in autoimmune hearing loss.

OBJECTIVE: To determine whether antibodies to supporting cells are associated with response to corticosteroids in patients with autoimmune sensorineural hearing loss. DESIGN: Prospective analysis of antibody to inner-ear antigens. SETTING: Collaborating otology practices in Pennsylvania, Michigan, and Indiana. PATIENTS: Sixty-three patients with rapidly progressive unilateral or bilateral sensorineural hearing loss of unknown cause suggestive of autoimmune sensorineural hearing loss. INTERVENTIONS: Pretreatment audiometry, serum analysis by Western blot (WB) and immunofluorescence (IF) tests, corticosteroid therapy, and follow-up audiometry. MAIN OUTCOME MEASURES: Antibody reactivity and audiogram changes were analyzed for association with response to treatment. RESULTS: More than half of the patients (37/63) had antibodies to both a 68- to 72-kDa protein and to inner-ear supporting cells, 16 patients had positive results on one assay only, and 10 had negative results on both. Twenty-eight patients improved and 35 did not. The WB findings did not correlate with response. Of the WB-positive patients, 49% (21/43) improved, as did 35% (7/20) of the WB-negative patients (P = .30). In contrast, 53% (25/47) of IF-positive patients improved, compared with only 19% (3/16) in the IF-negative group (P = .02). Of those who improved, 89% (25/28) were IF positive. CONCLUSIONS: Antibody to an inner-ear supporting cell antigen was significantly associated with hearing improvement after corticosteroid therapy (relative rate, 2.8). Patients with IF-positive serum are nearly 3 times more likely to experience improved hearing with corticosteroid treatment than those who are IF negative. Antibodies to inner-ear supporting cell antigen may have value in diagnosis and treatment of patients with autoimmune sensorineural hearing loss.

Adult↗

PubMed2005

Hemangiomas of the geniculate ganglion.

OBJECTIVE: To describe the presentation, evaluation, and management of patients with geniculate ganglion hemangioma. STUDY DESIGN: Retrospective case review. SETTING: Tertiary-care academic medical center. PATIENTS: Six patients with hemangiomas of the geniculate ganglion, evaluated and managed at a single institution. INTERVENTION: All patients underwent imaging and follow-up, with five of the patients undergoing operative intervention. MAIN OUTCOME MEASURES: Tumor size and extent, facial nerve and hearing function, histopathologic findings, and complications are discussed as a function of observation versus microsurgical excision. RESULTS: Six patients with ossifying hemangiomas of the geniculate ganglion were evaluated at a single institution over a 10-year period. These patients underwent operative intervention when their facial nerve function began to decline. Hearing was preserved in five of the six cases. Resection and grafting of the facial nerve was required in five of six cases. Two of the six cases were found to have histologic evidence of facial nerve infiltration on pathologic examination. CONCLUSION: The majority of these tumors infiltrated the facial nerve and could not be completely removed without excision of the nerve itself. Based on this experience, it would seem reasonable to defer surgical excision until facial nerve function has declined to grade 3 or worse. Whether earlier subtotal excision would result in better outcomes or not remains unanswered. This study presents several complicated scenarios that illustrate the difficulty of clinical decision-making in this disease. Associated clinical dilemmas and controversies are discussed.

Adult↗

PubMed2004

Identification and characterization of choline transporter-like protein 2, an inner ear glycoprotein of 68 and 72 kDa that is the target of antibody-induced hearing loss.

The Kresge Hearing Research Institute-3 (KHRI-3) antibody binds to a guinea pig inner ear supporting cell antigen (IESCA) and causes hearing loss. To gain insight into the mechanism of antibody-induced hearing loss, we used antibody immunoaffinity purification to isolate the IESCA, which was then sequenced by mass spectroscopy, revealing 10 guinea pig peptides identical to sequences in human choline transporter-like protein 2 (CTL2). Full-length CTL2 cDNA sequenced from guinea pig inner ear has 85.9% identity with the human cDNA. Consistent with its expression on the surface of supporting cells in the inner ear, CTL2 contains 10 predicted membrane-spanning regions with multiple N-glycosylation sites. The 68 and 72 kDa molecular forms of inner ear CTL2 are distinguished by sialic acid modification of the carbohydrate. The KHRI-3 antibody binds to an N-linked carbohydrate on CTL2 and presumably damages the organ of Corti by blocking the transporter function of this molecule. CTL2 mRNA and protein are abundantly expressed in human inner ear. Sera from patients with autoimmune hearing loss bind to guinea pig inner ear with the same pattern as CTL2 antibodies. Thus, CTL2 is a possible target of autoimmune hearing loss in humans.

Animals↗

PubMed2003

External auditory canal closure in cochlear implant surgery.

OBJECTIVE: To evaluate surgical techniques and complications associated with external auditory canal (EAC) closure in cochlear implant surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center with a large cochlear implant program. PATIENTS: Twenty-eight patients (8 adults and 20 children) underwent multichannel cochlear implantation with EAC closure. The follow-up periods ranged between 1 and 10 years. Closure of the EAC was performed in conjunction with implantation of ears with chronic suppurative otitis media or cochlear drill-out procedures for ossification, or for access to the cochlea in patients with abnormal temporal bone anatomy. A modified Rambo technique was used for EAC closure in all but one case. INTERVENTIONS: Cochlear implantation with EAC closure and subsequent clinical and radiologic follow-up. MAIN OUTCOME MEASURES: Postoperative complications or the development of cholesteatoma in the implanted ear. RESULTS: Cholesteatoma developed in the implanted ear in two patients. Breakdown of EAC closure occurred in one of these patients. The details of these patients are reviewed. CONCLUSION: Closure of EAC can be done with relatively low risk. Close and careful follow-up is required for early detection of a developing cholesteatoma.

Adolescent↗

PubMed2003

Prosthetic stimulation of the auditory system with intraneural electrodes.

Prosthetic electrical stimulation of the auditory system is presently accomplished either via scala tympani electrode arrays or via cochlear nucleus surface electrode arrays. Many of the early cochlear implant studies, however, used electrode arrays placed within the auditory nerve itself--either within the modiolus or within the trunk of the nerve. For many reasons, such intraneural electrode arrays were abandoned in favor of intrascalar arrays. There remain, however, several theoretical and practical reasons why intraneural arrays might be advantageous, and recent developments in electrode technology solve many of the problems posed by early attempts at intraneural stimulation. In this article, we review the history and current status of intraneural auditory stimulation, and present some preliminary results of this mode of stimulation in an animal model.

Animals↗

PubMed2002

Cochlear implants in young children.

The past 20 years have seen the cochlear implant evolve from an innovative but radical concept to the standard of care in the management of children with severe to profound hearing loss. All children receiving the cochlear implant achieve substantial benefit; however, performance gains are optimized by a team approach to the evaluation and management of these children. The critical elements of this team include audiologists, speech pathologists, and surgeons with specific interest, expertise, and dedication to the management of children with cochlear implants. Children are not well served by practitioners who delegate follow-up to educational programs not experienced in children with implants. Long-term involvement and dedication on the part of teachers, speech pathologists, audiologists, surgeons, and family are critical to maximizing the benefit the child receives.

Adolescent↗

PubMed2002

Cochlear implantation in chronic suppurative otitis media.

OBJECTIVE: To evaluate management options for cochlear implantation in patients with chronic suppurative otitis media. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center with a large cochlear implant program. PATIENTS: Ten patients with chronic suppurative otitis media who received cochlear implants were identified. Case history, etiology of hearing loss, and management of the ear with the implant were evaluated. INTERVENTIONS: Cochlear implantation and subsequent rehabilitation. MAIN OUTCOME MEASURES: Early and late complications were evaluated. RESULTS: No early or late complications were identified in this group of patients after an average follow-up period of about 4 years. CONCLUSION: Cochlear implantation can be safely achieved in patients with chronic suppurative otitis media. There are several options for the management of these patients, and the approach chosen should be individualized on the basis of clinical findings.

Adolescent↗