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Biomedical subjects

Peter S Roland

Publications and source records attributed to Peter S Roland.

At least 37 records · Page 2Linked to original sources

Vertigo and motion sickness. Part I: vestibular anatomy and physiology.

Control of the symptoms of vertigo and motion sickness requires consideration of the neurophysiology of areas both intrinsic and extrinsic to the vestibular system proper. We review the essential anatomy and physiology of the vestibular system and the associated vomiting reflex.

Area Postrema↗

Randomized, placebo-controlled evaluation of Cerumenex and Murine earwax removal products.

OBJECTIVE: To evaluate the efficacy of 2 ceruminolytic products, Cerumenex Eardrops (Purdue Frederick Company, Norwalk, Conn) and Murine Ear Drops (Abbott Laboratories, Abbott Park, Ill), in subjects with partial or complete occlusion of the ear canal due to cerumen. DESIGN: Randomized, subject- and observer-blind, placebo-controlled, clinical trial. SETTING: Corporate research clinic. PARTICIPANTS: From among 230 volunteers screened, 74 subjects (age, 22-66 [mean, 45] years) were enrolled in the study. Participants had baseline occlusion levels of mild (n = 10), moderate (n = 26), or complete (n = 38) impairment of tympanic membrane visualization. INTERVENTIONS: Subjects were randomly assigned to 1 of 3 treatments: Cerumenex (10% triethanolamine polypeptide oleate-condensate), Murine (6.5% carbamide peroxide), and a placebo, BSS Sterile Irrigating Solution (Alcon Laboratories Inc, Ft Worth, Tex). The test medication was instilled into 1 occluded ear for up to two 15-minute applications. Following the treatment, the subject's ear was irrigated with 50 mL of lukewarm water delivered at low pressure via a WaterPik irrigator equipped with a Grossan irrigator tip. Main Outcome Measure The degree of occlusion, measured against a previously established 4-point scale, was assessed and recorded at baseline and after each instillation and irrigation procedure. RESULTS: Neither Cerumenex nor Murine was superior to saline placebo. By the end of treatment, 29.2%, 15.4%, and 41.7% of subjects treated with Cerumenex, Murine, and placebo, respectively, experienced resolution of cerumen occlusion. These values were not statistically significantly different from one another. CONCLUSION: The currently marketed ceruminolytic products, Cerumenex and Murine, are no more effective than a saline placebo in removing earwax.

Adult↗

Ototoxicity of ototopical antibiotic drops in humans.

OBJECTIVE: We sought to determine the incidence of injury to the cochlea or vestibular system from the use of ototopic antibiotic ear drops. STUDY DESIGN: We conducted a MEDLINE search of the published literature from 1966 to the present using the search items of "ototopic antibiotics," "ototopic drops," "antibiotic resistance," and others to identify pertinent articles. These articles were reviewed and graded according to evidence quality. Forty-four articles were found; 27 articles were considered appropriate for review and 14 of these articles were thought to warrant further extensive review. The latter 14 articles dealt directly with the evaluation of either hearing loss or changes in vestibular function after the use of ototopic ear drops. We eliminated studies that did not consider hearing or vestibular function. We considered only articles in the English language, eliminating articles that not address the ototoxicity of ototopical ear drops. RESULTS: Most of these articles were in the level 3 to 3b category. Two of the articles were in the 1b category, evaluating evidence-based studies. An article that reviewed case reports of ototopical ototoxicity and a survey article are included in this study, as case reports of ototopical ototoxicity and survey articles. CONCLUSION: We found a total of 54 cases of gentamicin vestibular toxicity and, in 24 of these patients, cochlear toxicity was also documented. Our review also found 11 cases of cochlear and 2 cases of vestibular toxicity in neomycin-based ear drops.

Administration, Topical↗

Animal ototoxicity of topical antibiotics and the relevance to clinical treatment of human subjects.

OBJECTIVE: The objective of this study was to systematically review the literature on animal ototoxicity from ototopical medications. A secondary objective was to assess the relevance of animal data to the use of ototopical drops in clinical situations involving humans. STUDY DESIGN: We performed a MEDLINE search of the published literature using appropriate search terms to identify pertinent articles, which were reviewed, summarized, and tabulated. RESULTS: One hundred seventy-three articles were reviewed; 61 articles were appropriate to the study question and were further analyzed. CONCLUSIONS: Virtually all studies demonstrate that aminoglycoside antibiotics, when applied topically into the middle ear space, are ototoxic in experimental animals.

Administration, Topical↗

The development of antibiotic resistant organisms with the use of ototopical medications.

OBJECTIVE: There is growing concern over the use of systemic antibiotics and the development of bacterial resistance. The question remains as to whether ototopical medications may also promote antibiotic-resistant organisms, either on a local level (in the ear) or in other areas of the aerodigestive tract. We performed an evidence-based review to answer the following clinical question, "Do antibiotic ototopical medications induce antibiotic resistant organisms?" STUDY DESIGN: We performed a MEDLINE search of the published literature from 1966 to the present. We used appropriate search terms such as "ototopical antibiotics," "ototopical drops," "antibiotic resistance," "topical antibiotics and otitis externa," "otitis externa and treatment," "otitis externa and antibiotic drops," "otitis externa and ototopical drops," "otitis media," "otitis media and treatment," "otitis media and antibiotic drops," "chronic suppurative otitis media," "chronic suppurative otitis media and treatment," "chronic suppurative otitis media and antibiotic drops," " otitis externa and resistant organisms," "otitis media and resistant organisms," "chronic suppurative otitis media and resistant organisms," "ophthalmic antibiotic drops," "draining ear," "P.E. tube otorrhea," "pressure equalizing tube otorrhea," "pressure equalizing tube otorrhea and treatment," and "pressure equalizing tube otorrhea and ototopical therapy" to identify pertinent articles. These articles were reviewed and graded according to the evidence quality. RESULTS: After an initial screening of over 2,500 articles, 38 articles were analyzed further; of these, 11 were determined to warrant extensive review. Eight articles evaluated chronic suppurative otitis media; 2, otitis externa; and 1, post-tympanostomy tube otorrhea, whereas 3 others studied systemic absorption. Of the 8 chronic suppurative otitis media studies, there were thought to be 5 grade 2B studies, 1 grade 1B study, and 1 grade 2C study. These studies did not demonstrate a propensity for the development of resistant organisms. No study answered the question as to whether resistance to systemic antibiotics might occur in otitis externa. CONCLUSIONS: Overall grade B evidence seems to indicate that no significant antibiotic resistance develops from the use of ototopical antibiotic treatment.

Acute Disease↗

Management of pseudomeningocele following neurotologic procedures.

OBJECTIVES: A pseudomeningocele results from the escape of cerebrospinal fluid through a dural defect with trapping of subarachnoid fluid in surrounding soft tissue. The present study evaluates the incidence of pseudomeningocele following neurotologic procedures and delineates an algorithm for management. METHODS: A retrospective review of 375 consecutive patients undergoing neurotologic procedures at a single institution identified 17 patients with the postoperative complication of pseudomeningocele. RESULTS: The incidence of pseudomeningocele formation was 4.5% in the present study. Fourteen pseudomeningoceles resolved with nonoperative management including pressure dressing, bed rest, and lumbar spinal drainage. Three patients failed nonoperative management and required surgical procedures for resolution. All patients ultimately had resolution of their pseudomeningocele. CONCLUSION: Skull-base pseudomeningoceles occur as a complication following neurotologic procedures and can cause complications as they enlarge. The majority of these cases can be dealt with in a nonsurgical manner, but those failing to respond to conservative management should be considered for surgical intervention.

Adult↗

Topical ciprofloxacin/dexamethasone otic suspension is superior to ofloxacin otic solution in the treatment of granulation tissue in children with acute otitis media with otorrhea through tympanostomy tubes.

OBJECTIVE: Comparison of topical ciprofloxacin/dexamethasone otic suspension (CIP/DEX) to ofloxacin otic solution (OFL) for treatment of granulation tissue in children with AOMT. STUDY DESIGN: 599 children aged >/=6 months to 12 years with AOMT of up to 3 weeks' duration were enrolled. Patients received either CIP/DEX 4 drops twice daily for 7 days or OFL 5 drops twice daily for 10 days. Granulation tissue severity was graded at clinic visits on days 1, 3, 11, and 18. RESULTS: Granulation tissue was present in 90 of 599 AOMT patients (15.0%) at baseline. CIP/DEX treatment was superior to OFL for reduction of granulation tissue at the day 11 visit (81.3% compared with 56.1%, P = 0.0067) and the day 18 visit (91.7% compared with 73.2%, P = 0.0223). Both topical otic preparations are safe and well tolerated in pediatric patients. CONCLUSION: CIP/DEX was superior to OFL in the treatment of granulation tissue in children with AOMT.

Administration, Topical↗

A cost threshold analysis of ciprofloxacin-dexamethasone versus ofloxacin for acute otitis media in pediatric patients with tympanostomy tubes.

OBJECTIVE: The aim of this study was to determine the cost-effectiveness hreshold of a ciprofloxacin 0.3% and dexamethasone 0.1% (CD) otic suspension relative to olfloxacin otic solution (OFX) for the treatment of acute otitis media in pediatric patients with tympanostomy tubes (AOMT). METHODS: This study used a decision-analytic model to simulate the costs and consequences of the ototopical treatment of AOMT. The AOMT model consisted of 3 tiers of antimicrobial therapy. Each successive tier represented the repeat treatment of clinical failures from the preceding tier. Patients were modeled for treatment until cured or until third-tier therapy was complete, at which time patients were considered cured. First-tier therapy modeled a comparison of CD and OFX using efficacy rates taken from a randomized clinical trial with a population of 599 patients. Second-tier therapy modeled the use of amoxicillin and clavulanic acid using an efficacy rate taken from the medical literature. Third-tier therapy was modeled as being pathogen specific and could follow 1 of 3 possible clinical pathways: (1) PO fluconazole, (2) IM ceftriaxone, or (3) IV antibiotics administered in a hospital setting. Third-tier therapeutic pathway probabilities were based on the microbiologic spectrum of the treatment failures from the clinical trial. Cost information (in year-2003 US dollars) was taken from accepted cost reference sources and presented from the perspective of a third-party payer. The economic outcome of interest was the cost-effectiveness threshold of CD relative to OFX. RESULTS: Given the model parameters, CD had a cost-effectiveness threshold value of 4.5 times the wholesale acquisition cost of OFX. Based on actual cost, first-tier CD therapy was more cost-effective than OFX up to a threshold price of US 152.64 dollars. CONCLUSION: In this decision-analytic model, CD was more cost-effective than OFX for AOMT therapy in pediatric patients up to a threshold price of 4.5 times the price of OFX.

Anti-Bacterial Agents↗

Functional magnetic resonance imaging of activation in subcortical auditory pathway.

OBJECTIVES: Functional magnetic resonance imaging (fMRI) has been used to investigate activation of the auditory cortex; however, assessment of activation in the subcortical auditory pathway has been challenging. The aim of this study was to examine neural correlates of cortical and subcortical auditory activation evoked by pure-tone stimulus using silent fMRI. STUDY DESIGN: Prospective analysis. METHODS: Seventeen normal-hearing volunteers (7 male, 10 female; age range, 14-37 yrs) underwent silent fMRI. An audiometer was used to deliver pure tones of 1000 Hz to the left ear. Pure tones were presented at hearing thresholds determined in the scanner. Brain regions showing increased activation during pure-tone stimulus presentation were mapped and auditory activations exceeding P <.001 were included in the analysis. RESULTS: Pure-tone stimuli evoked bilateral activation in cortical regions of the transverse and superior temporal gyri and the planum temporale. Activation in subcortical structures included the medial geniculate body, inferior colliculus, lateral lemniscus, superior olivary complex, and cochlear nucleus. CONCLUSIONS: Silent functional magnetic resonance imaging findings documented the feasibility of detecting activation elicited by pure tone along the cortical and subcortical auditory pathway. The use of this technique in the assessment of disorders with auditory dysfunction merits further investigation.

Acoustic Stimulation↗

Clinical results with the Med-El compressed and split arrays in the United States.

OBJECTIVE: To determine the indications for which the Med-El compressed and split arrays have been used in the United States, to assess the success achieved in insertion, to determine hearing outcomes, and assess complications associated with using these arrays. STUDY DESIGN: Retrospective review of data gathered during the US clinical trial. METHODS: Data were extracted concerning indications for use, depth of insertion, number of electrodes in use, 3 and 6 month performance outcomes, and complications. The results obtained in postmeningitic patients using the compressed array were compared with results of patients using the split array. RESULTS: Six adults and 22 children have been implanted with the compressed array. The principal indications have been postmeningitis or congenital cochlear malformations. The average improvement seen in the Meaningful Auditory Integration Scale scores was 17.6 for the compressed array group and 13.9 for the split array group. The same number of electrodes was inserted on average for both groups, with comparable numbers of electrodes in use. CONCLUSIONS: The Med-El compressed array is an alternative to a standard or split array in managing patients with postmeningitic deafness or congenital cochlear malformations. Benefits to these patients are most clearly seen in subjective measures.

Adolescent↗

Silent functional magnetic resonance imaging (FMRI) of tonotopicity and stimulus intensity coding in human primary auditory cortex.

OBJECTIVES: The aims of this study were to determine the feasibility of obtaining auditory cortex activation evoked by pure tones presented at threshold and suprathreshold hearing levels, to evaluate tonotopicity of the primary auditory cortex, and to determine the effect of stimulus intensity on auditory cortex activation using silent functional magnetic resonance imaging (fMRI). METHODS: Sixteen subjects with normal hearing underwent silent fMRI. An audiometer was used to deliver pure tones of 1000, 2000, and 4000 Hz to the left ear. Two levels of acoustic stimulation were used: 1). threshold, hearing level determined in the scanner room and 2). suprathreshold, 70 dB hearing loss (HL). Tonotopicity and stimulus intensity coding was assessed on the basis of the location, extent, and amount of the auditory cortex activation. RESULTS: The localization of activation moved to more medial and posterior regions of the primary auditory cortex as the frequency of the pure tone increased. Compared with a threshold stimulus, a suprathreshold stimulus evoked the same regions with increased spatial extent. The average increase in the right auditory cortex activation in response to suprathreshold stimulus was 57% at 1000, 51% at 2000, and 45% at 4000 Hz compared with that activated by the threshold stimulus. CONCLUSIONS: Silent fMRI can be used to evaluate auditory cortex activation using low-intensity stimuli. The level of stimulus intensity increases the amount of auditory cortex activation and influences the fMRI mapping of the tonotopic organization of the primary auditory cortex.

Adolescent↗

Histopathological basis of hearing impairment in Wolf-Hirschhorn syndrome.

OBJECTIVES/HYPOTHESIS: To perform histological examination of temporal bones acquired from an infant with Wolf-Hirschhorn syndrome with an emphasis on identifying abnormalities that might be responsible for hearing impairment in this disorder. STUDY DESIGN: Retrospective case review. METHODS: Temporal bones were taken at autopsy from a 10-month-old infant with Wolf-Hirschhorn syndrome. The right-side temporal bone was studied by microdissection. The middle ear was examined, and the inner ear sensory organs dissected for study by light microscopy. The left-side temporal bone was embedded in celloidin, and sections were cut for microscopic examination. RESULTS: Chronic otitis media was observed in both ears. Inflammation, effusion, and adhesions were present in the middle ear space. The malleus was malformed, and the chorda tympani nerve was found to pass through the bone of the malleus bilaterally. There was an area of sharply defined outer hair cell loss in the lower basal turn of the right-side organ of Corti, and defects were noted in the bone of the apical osseous spiral lamina in both cochleae. CONCLUSION: In addition to the presence of otitis media, the likelihood of congenital abnormalities of the middle and inner ear should be considered in the assessment of patients with Wolf-Hirschhorn syndrome with hearing impairment.

Abnormalities, Multiple↗

Cochlear degeneration in leigh disease: histopathologic features.

OBJECTIVE: To describe pathologic findings from temporal bones acquired from an infant with Leigh disease. STUDY DESIGN: Retrospective case review. MATERIALS AND METHODS: Temporal bones were taken at autopsy from an 8-month-old infant with Leigh disease. The right temporal bone was studied by microdissection. The middle ear was examined and the inner ear sensory organs dissected for study by light microscopy. The left temporal bone was embedded in celloidin, and sections were cut for microscopic examination. RESULTS: Middle ear structures were normal bilaterally. There was, however, evidence of otitis media in both middle ears, which was more severe on the left side. Inner and outer hair cell loss, patchy degeneration of organ of Corti, and loss of nerve fibers in the osseous spiral lamina were found in the basal and middle turns of both cochleas. Basophilic deposits in the stria vascularis were observed in the apical portion of the left cochlea. CONCLUSIONS: Inner ear sensorineural degeneration may occur in Leigh disease. Possible cochlear dysfunction caused by the degenerative changes needs to be considered in the hearing assessment of patients with Leigh disease.

Autopsy↗

Efficacy and safety of topical ciprofloxacin/dexamethasone versus neomycin/polymyxin B/hydrocortisone for otitis externa.

OBJECTIVES: To compare the efficacy and safety of ciprofloxacin 0.3%/dexamethasone 0.1% (CIP/DEX) otic suspension with that of neomycin 0.35%/polymyxin B 10,000 IU/mL/hydrocortisone 1.0% (N/P/H) otic suspension in patients with acute otitis externa (AOE). STUDY DESIGN: Randomized, observer-masked, parallel-group, multicenter study. Patients were randomized to 7 days treatment with either CIP/DEX 3-4 drops twice daily or N/P/H 3-4 drops three times daily. POPULATION: Patients of either sex and older than 1 year, with a clinical diagnosis of mild, moderate, or severe AOE and intact tympanic membranes were recruited to participate. OUTCOMES MEASURED: Signs and symptoms of AOE, including ear inflammation, tenderness, edema and discharge (assessed on Days 3, 8 [End-of-Therapy] and 18 [Test-of-Cure]); microbiologic eradication (presumed or documented); and frequency of adverse events. RESULTS: Patients enrolled numbered 468. In culture-positive patients who met the inclusion criteria (N = 396), clinical cure rates at Day 18 were significantly higher with CIP/DEX than with N/P/H (90.9% vs. 83.9%; p = 0.0375), as were microbiologic eradication rates (94.7% vs. 86.0%; p = 0.0057). In addition, the clinical response was significantly better with CIP/DEX than with N/P/H at Days 3 and 18 (p = 0.0279 and p = 0.0321, respectively), as was the reduction in ear inflammation at Day 18 (p = 0.0268). Both preparations were well tolerated in pediatric and adult patients. CONCLUSIONS: 7 days treatment with CIP/DEX otic suspension administered twice daily is clinically and microbiologically superior to N/P/H otic suspension administered 3 times daily in the treatment of mild to severe AOE, and is equally well tolerated.

Administration, Topical↗

Topical ciprofloxacin/dexamethasone otic suspension is superior to ofloxacin otic solution in the treatment of children with acute otitis media with otorrhea through tympanostomy tubes.

OBJECTIVE: To determine the efficacy and safety of topical ciprofloxacin/dexamethasone otic suspension compared with ofloxacin otic solution in the treatment of acute otitis media with otorrhea through tympanostomy tubes (AOMT) in pediatric patients. METHODS: This multicenter, prospective, randomized, observer-masked, parallel-group study was conducted at 39 sites in 599 children aged >or=6 months to 12 years with an AOMT episode of <or=3 weeks' duration. The mean age of patients was 2.5 years (standard deviation: 2.37 years). Patients received either ciprofloxacin 0.3%/dexamethasone 0.1% otic suspension 4 drops twice daily for 7 days or ofloxacin 0.3% otic solution 5 drops twice daily for 10 days. Clinical signs and symptoms of AOMT were evaluated at clinic visits on days 1 (baseline), 3 (on therapy), 11 (end of therapy), and 18 (test of cure). A patient diary was used to measure time to cessation of otorrhea. Principal pretherapy pathogens included Streptococcus pneumoniae (16.8%), Staphylococcus aureus (13.0%), Pseudomonas aeruginosa (12.7%), Haemophilus influenzae (12.4%), S epidermidis (10.2%), and Moraxella catarrhalis (4.1%). RESULTS: Ciprofloxacin/dexamethasone is superior to ofloxacin for clinical cure (90% vs 78%) and microbiologic success (92% vs 81.8%) at the test-of-cure visit, produces fewer treatment failures (4.4% vs 14.1%), and results in a shorter median time to cessation of otorrhea (4 days vs 6 days). Ciprofloxacin/dexamethasone treatment is also superior to improvement in clinical response by visit, absence of otorrhea by visit, and reduction of otorrhea volume by visit. Both topical otic preparations are safe and well tolerated in pediatric patients. No change in speech recognition threshold or decrease in hearing from baseline, based on audiometric testing, was noted with either regimen. CONCLUSION: Topical ciprofloxacin/dexamethasone treatment is superior to topical ofloxacin in the treatment of AOMT.

Acute Disease↗