scispace - formally typeset
Search or ask a question
Author

Marlan R. Hansen

Bio: Marlan R. Hansen is an academic researcher from University of Iowa. The author has contributed to research in topics: Cochlear implant & Hearing loss. The author has an hindex of 36, co-authored 179 publications receiving 4267 citations. Previous affiliations of Marlan R. Hansen include University of Utah & University of Iowa Hospitals and Clinics.


Papers
More filters
Journal ArticleDOI
TL;DR: The data suggest that, in general, the advantages gained for speech recognition in noise by preserving residual hearing exist, unless the hearing loss approaches profound levels.
Abstract: Acoustic plus electric (electric-acoustic) speech processing has been successful in highlighting the important role of articulation information in consonant recognition in those adults that have profound high-frequency hearing loss at frequencies greater than 1500 Hz and less than 60% discrimination scores. Eighty-seven subjects were enrolled in an adult Hybrid multicenter Food and Drug Administration clinical trial. Immediate hearing preservation was accomplished in 85/87 subjects. Over time (3 months to 5 years), some hearing preservation was maintained in 91% of the group. Combined electric-acoustic processing enabled most of this group of volunteers to gain improved speech understanding, compared to their preoperative hearing, with bilateral hearing aids. Most have preservation of low-frequency acoustic hearing within 15 dB of their preoperative pure tone levels. Those with greater losses (>30 dB) also benefited from the combination of electric-acoustic speech processing. Postoperatively, in the electric-acoustic processing condition, loss of low-frequency hearing did not correlate with improvements in speech perception scores in quiet. Sixteen subjects were identified as poor performers in that they did not achieve a significant improvement through electric-acoustic processing. A multiple regression analysis determined that 91% of the variance in the poorly performing group can be explained by the preoperative speech recognition score and duration of deafness. Signal-to-noise ratios for speech understanding in noise improved more than 9 dB in some individuals in the electric-acoustic processing condition. The relation between speech understanding in noise thresholds and residual low-frequency acoustic hearing is significant (r = 0.62; p < 0.05). The data suggest that, in general, the advantages gained for speech recognition in noise by preserving residual hearing exist, unless the hearing loss approaches profound levels. Preservation of residual low-frequency hearing should be considered when expanding candidate selection criteria for standard cochlear implants. Duration of profound high-frequency hearing loss appears to be an important variable when determining selection criteria for the Hybrid implant.

201 citations

Journal ArticleDOI
TL;DR: The results suggest that removal of unilateral AN through an MCF approach when the tumor is small and hearing is good provides the best opportunity for hearing preservation and normal facial nerve function.
Abstract: Objective:Evaluate factors affecting outcomes of small acoustic neuroma (AN) removal via a middle cranial fossa (MCF) approach, and compare results to published data on observation and radiation therapy.Study Design:Retrospective chart review.Setting:Academic tertiary referral center.Methods:162 con

163 citations

Journal ArticleDOI
TL;DR: This study was designed to evaluate the authors' experience with canal wall reconstruction (CWR) tympanomastoidectomy with mastoid obliteration in the treatment of chronic otitis media with cholesteatoma.
Abstract: Objectives: This study was designed to evaluate the authors' experience with canal wall reconstruction (CWR) tympanomastoidectomy with mastoid obliteration in the treatment of chronic otitis media with cholesteatoma. Study Design: Institutional review board approved retrospective case review. Methods: Retrospective review was performed of all patients undergoing CWR tympanomastoidectomy with mastoid obliteration from 1997 to 2004. Data included pre- and postoperative audiometry, findings at second look surgery with ossiculoplasty, and postoperative complications including wound infection and canal wall displacement. Results: One hundred thirty ears in 127 adults and children underwent the procedure. Mean time postoperative was 48 (range 2-94) months. A second look ossiculoplasty was performed in 102 (78%). Percentage of ears that remain safe without evidence of recurrence was 98.5. The postoperative infection rate decreased from an initial rate of 14.3% to 4.5% for the last 88 ears after protocol modification. Recurrence occurred in two (1.5%) patients, requiring conversion to a canal wall down mastoidectomy. Conclusions: A CWR technique can provide improved intraoperative exposure of the middle ear and mastoid without creating a mastoid bowl and reduces the incidence of recurrent disease. A single procedure is used for all patients with acquired cholesteatoma, including children.

144 citations

Journal ArticleDOI
TL;DR: Survition of SGNs under depolarizing conditions involves additivity among a depolarization-independent autocrine pathway, a cAMP-dependent pathway, and a CaMK- dependent pathway.
Abstract: We have shown previously that BDNF, neurotrophin-3 (NT-3), chlorphenylthio-cAMP (cpt-cAMP) (a permeant cAMP analog), and membrane depolarization promote spiral ganglion neuron (SGN) survival in vitro in an additive manner, depolarization having the greatest efficacy. Expression of both BDNF and of NT-3 is detectable in cultured SGNs after plating in either depolarizing or nondepolarizing medium. These neurotrophins promote survival by an autocrine mechanism; TrkB-IgG or TrkC-IgG, which block neurotrophin binding to, respectively, TrkB and TrkC, partially inhibit the trophic effect of depolarization. The mitogen-activated protein kinase kinase inhibitor PD98059 and the phosphatidylinositol-3-OH kinase inhibitor LY294002 both abolish trophic support by neurotrophins but only partially inhibit support by depolarization. Inhibition by these compounds is not additive with inhibition by Trk-IgGs. The cAMP antagonist Rp-adenosine-3',5'-cyclic-phosphorothioate (Rp-cAMPS) abolishes survival attributable to cpt-cAMP but has no effect on that attributable to neurotrophins, nor do inhibitors of neurotrophin-dependent survival affect survival attributable to cpt-cAMP. However, Rp-cAMPS does partially inhibit depolarization-dependent survival, an inhibition that is additive with that by Trk-IgGs, PD98059, or LY294002. Moreover, Rp-cAMPS prevents depolarization-dependent survival of PC12 cells maintained in subthreshold levels of NGF. Inhibition of Ca(2+)/calmodulin-dependent protein kinases (CaMKs) with KN-62 reduces SGN survival independently of Rp-cAMPS, Trk-IgGs, and LY294002 and additively with them. Combined inhibition of Trk, cAMP, and CaMK signaling prevents depolarization-dependent survival. Thus, survival of SGNs under depolarizing conditions involves additivity among a depolarization-independent autocrine pathway, a cAMP-dependent pathway, and a CaMK-dependent pathway.

141 citations

Journal ArticleDOI
TL;DR: In patients with severe hearing loss and recalcitrant vertigo attacks because of MD, simultaneous labyrinthectomy and CI effectively relieves Vertigo attacks and improves auditory function.
Abstract: Objective Compare preoperative and postoperative performance in patients undergoing cochlear implantation (CI) for unilateral severe-to-profound sensorineural hearing loss (single-sided deafness, SSD). Study Design IRB-approved, prospective Setting Tertiary center Patients Twenty-nine patients have undergone CI for SSD. SSD was due to Meniere’s disease (MD) in 10 subjects; these also suffered from recalcitrant vertigo spells and in these 10 patients along with 2 others the CI was placed simultaneous with a labyrinthectomy. Intervention(s) CI with or without labyrinthectomy. Main Outcome Measure(s) CNC word and AzBio sentences in quiet were administered to the implanted ear. A multiple-loudspeaker sound localization test was administered in the bilateral listening condition. All data were collected preoperatively and 3, 6, and 12 months postoperatively with postoperative data available for 19 subjects. Additionally, a tinnitus handicap questionnaire is administered pre- and 12-months post-operatively. Results CNC word and AzBio sentence scores showed improvement in the implanted ear. Sound localization appeared to improve in an experience-dependent fashion in some patients. Most patients reported diminished tinnitus after cochlear implantation. All patients undergoing labyrinthectomy experienced resolution of vertigo attacks. Conclusion CI restores auditory function to the deafened ear. Additionally, the binaural input appears to improve sound localization for most patients. In patients with severe hearing loss and recalcitrant vertigo attacks because of MD, simultaneous labyrinthectomy and CI effectively relieves vertigo attacks and improves auditory function.

140 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The ACC and AHA have collaborated with the National Heart, Lung, and Blood Institute and stakeholder and professional organizations to develop guidelines, standards, and policies that promote optimal patient care and cardiovascular health.
Abstract: Preamble and Transition to ACC/AHA Guidelines to Reduce Cardiovascular Risk S50 The goals of the American College of Cardiology (ACC) and the American Heart Association (AHA) are to prevent cardiovascular diseases (CVD); improve the management of people who have these diseases through professional education and research; and develop guidelines, standards, and policies that promote optimal patient care and cardiovascular health. Toward these objectives, the ACC and AHA have collaborated with the National Heart, Lung, and Blood Institute (NHLBI) and stakeholder and professional organizations to develop …

3,524 citations

Journal ArticleDOI
TL;DR: The 2017-18 FACC/FAHA curriculum vitae will focus on adolescent and young adult FACC and FAHA education, as well as leadership, self-confidence, and self-consistency.
Abstract: Jeffrey L. Anderson, MD, FACC, FAHA, Chair Jonathan L. Halperin, MD, FACC, FAHA, Chair-Elect Nancy M. Albert, PhD, RN, FAHA Biykem Bozkurt, MD, PhD, FACC, FAHA Ralph G. Brindis, MD, MPH, MACC Lesley H. Curtis, PhD, FAHA David DeMets, PhD[¶¶][1] Lee A. Fleisher, MD, FACC, FAHA Samuel

2,291 citations

Journal ArticleDOI
TL;DR: It is useful to envision ERBB signalling as a bow-tie-configured, evolvable network, which shares modularity, redundancy and control circuits with robust biological and engineered systems.
Abstract: Signalling through the ERBB/HER receptors is intricately involved in human cancer and already serves as a target for several cancer drugs. Because of its inherent complexity, it is useful to envision ERBB signalling as a bow-tie-configured, evolvable network, which shares modularity, redundancy and control circuits with robust biological and engineered systems. Because network fragility is an inevitable trade-off of robustness, systems-level understanding is expected to generate therapeutic opportunities to intercept aberrant network activation.

1,907 citations

Journal ArticleDOI
TL;DR: This text is a general introduction to radiation biology and a complete, self-contained course especially for residents in diagnostic radiology and nuclear medicine that follows the Syllabus in Radiation Biology of the RSNA.
Abstract: The text consists of two sections, one for those studying or practicing diagnostic radiology, nuclear medicine and radiation oncology; the other for those engaged in the study or clinical practice of radiation oncology--a new chapter, on radiologic terrorism, is specifically for those in the radiation sciences who would manage exposed individuals in the event of a terrorist event. The 17 chapters in Section I represent a general introduction to radiation biology and a complete, self-contained course especially for residents in diagnostic radiology and nuclear medicine that follows the Syllabus in Radiation Biology of the RSNA. The 11 chapters in Section II address more in-depth topics in radiation oncology, such as cancer biology, retreatment after radiotherapy, chemotherapeutic agents and hyperthermia.

1,359 citations

Journal ArticleDOI
TL;DR: An overview of the clinical aspects, management, and treatment options for von Hippel-Lindau disease is presented.

1,296 citations