John-Martin Hempel

Ototoxicity of artemether/lumefantrine in the treatment of falciparum malaria: a randomized trial

BackgroundDue to increasing drug resistance, artemisinin-based combination chemotherapy (ACT) has become the first-line treatment of falciparum malaria in many endemic countries. However, irreversible ototoxicity associated with artemether/lumefantrine (AL) has been reported recently and suggested to be a serious limitation in the use of ACT. The aim of the study was to compare ototoxicity, tolerability, and efficacy of ACT with that of quinine and atovaquone/proguanil in the treatment of uncomplicated falciparum malaria.MethodsNinety-seven patients in south-west Ethiopia with slide-confirmed malaria were randomly assigned to receive either artemether/lumefantrine or quinine or atovaquone/proguanil and followed-up for 90 days. Comprehensive audiovestibular testing by pure tone audiometry (PTA), transitory evoked (TE) and distortion product (DP) otoacoustic emissions (OAE) and brain stem evoked response audiometry (BERA) was done before enrolment and after seven, 28 and 90 days.ResultsPTA and DP-OAE levels revealed transient significant cochlear hearing loss in patients treated with quinine but not in those treated with artemether/lumefantrine or atovaquone/proguanil. TE-OAE could be elicited in all examinations, except for three patients in the Q group on day 7, who suffered a transient hearing loss greater than 30 dB. There was no evidence of drug-induced brain stem lesions by BERA measurements.ConclusionThere was no detrimental effect of a standard oral regimen of artemether/lumefantrine on peripheral hearing or brainstem auditory pathways in patients with uncomplicated falciparum malaria. In contrast, transient hearing loss is common after quinine therapy and due to temporary outer hair cell dysfunction.

Effect of cochlear implantation on horizontal semicircular canal function.

The objective of this study was to assess the influence of a cochlear implant (CI) on horizontal semicircular canal (hSCC) function, to test the correlation with symptomatic vertigo and to identify possible risk factors for a postoperative vestibular impairment. In a prospective observational study design, forty-seven adult patients who had undergone cochlear implantation at Cochlear Implant Center at a tertiary referral university hospital, Munich, between 2003 and 2007, were studied. Postoperative vertigo symptoms were assessed using a questionnaire followed by a structured interview. Patients were subjected to caloric and rotational chair vestibular function tests pre- and postoperatively. The CI operation was performed with a retroauricular transmastoidal approach by three different surgeons. Thirty-six implants were Cochlear Nucleus 24 devices and 11 implants were MedEl devices. Twenty-one (45%) patients reported vertigo symptoms after CI. Functional testing of the hSCC yielded valid results in 45 of the 47 patients. Thirty-two percent of patients had a substantially reduced hSCC function after CI. Responses of caloric irrigation showed a significant worsening postoperatively in the CI ears. No direct correlation between a decrease in caloric response and risk of postoperative vertigo symptoms could be established. For the criteria age, sex, implant type, surgeon, cause of deafness, petrous bone CT findings and preoperative vertigo, there were no significant differences between the patients with and the patients without postoperative vertigo. Besides morphological changes, a cochlear implantation also causes functional damage of vestibular parts of the labyrinth. Our study showed a significant worsening of the caloric response. However, this alteration did not lead to vertigo complaints in all patients. It is therefore presumed that additional damage to sensory or visual afferents and central vestibular compensatory mechanisms play a role.

Labyrinth dysfunction 8 months after cochlear implantation: a case report.

Objective: Investigate whether the cochleostomy is a possible port of entry for pneumolabyrinth and a resulting vertigo in patients provided with a cochlear implant. Study Design: Retrospective case review. Setting: Ludwig-Maximilians University of Munich, Hospital Grosshadern. Patient: 62-year-old patient who underwent implantation of a HiFocus II cochlear implant with positioner from Advanced Bionics (CLARION). Eight months postoperatively, the patient reported rotatory vertigo and right-side tinnitus after he had blown his nose harder than usual during an episode of rhinitis. Interventions: Preoperative and postoperative testing of both the petrosal bone with a CT scan and of balance function. Main Outcome Measure: Air inclusion in the labyrinth. Results: In contrast to the preoperative high resolution computed tomography (CT) scan, air inclusion was seen in the labyrinth during the episode of vertigo. At the same time, balance function tests with Frenzel glasses revealed both spontaneous and provoked horizontal nystagmus to the right side. At follow-up 8 weeks later, the level of vertigo had significantly decreased. Twelve months later, the control CT showed the cochlear implant positioned correctly and no visible air in the labyrinth. Conclusion: It is known that placement of the HiFocus II with Positioner from CLARION requires a relatively large cochleostomy of 1.5 mm. Moreover, in the connective tissue seal between the electrode and the positioner, the latter reaches into the tympanic cavity, and this is possibly the weak point. Further investigation will be needed to determine whether the large cochleostomy with the HiFocus II with positioner increases the predisposition to labyrinth dysfunction.

Prevalence and Characteristics of Preoperative Balance Disorders in Cochlear Implant Candidates

Objectives: The aim of this study was to elucidate the frequency and characteristics of preoperative vertigo symptoms in patients who undergo cochlear implantation (CI), in order to differentiate them from CI-related symptoms. Methods: In a prospective observational study, 47 adult CI candidates were asked about vertigo problems on a questionnaire. A subdivision into 3 groups was done: Group A (probable otogenic vertigo), group B (possible otogenic vertigo), and group C (not otogenic vertigo). Horizontal semicircular canal function was measured. Patients with vertigo complaints were compared to patients without vertigo with regard to the presence of abnormal vestibular function findings. Results: Twenty-five patients (53%) reported preoperative vertigo problems. In 21 (84%), the patients history suggested a probable (group A) or possible (group B) otogenic origin. Patients with vertigo more often had abnormal findings on vestibular function testing than did patients without vertigo. This difference, however, was not statistically significant. Conclusions: A considerable number of CI candidates have preoperative vertigo symptoms. These cannot be explained by horizontal semicircular canal function alone. In order to understand why CI patients develop postoperative vertigo, analysis of prospective preoperative vestibular function test findings and vertigo symptoms is necessary.

Biomechanics and injury risk of a headbutt

Headbutt is a relevant type of a criminal assault that can result in injuries. The aim of this study was to collect basic biomechanical data and assess the injury risk associated with a headbutt. Series of measurements were carried out with volunteers with and without relevant soccer heading experience, and the impact velocity of the striking head was measured. A soccer ball was used as a surrogate of the stationary victim’s head. Two scenarios were considered: one corresponding to the typical headbutt situation, i.e. short movement of the assailant’s head without backswing, and one representing the worst case, i.e. the most severe head impact without time or space constraints for the assailant. The results as well as epidemiological data from court cases and a large Munich’s university clinic show that a typical headbutt is not likely to lead to life-threatening injuries, but bony injuries of the face can easily occur. Under certain circumstances (support of the victim’s head, secondary impact on the ground etc.), severe injuries with potentially lethal outcomes are possible. A thorough analysis of each case is thus an imperative. The (soccer) heading experience does not influence the velocity of the headbutt.

Botulinum toxin A prolongs functional durability of voice prostheses in laryngectomees with pharyngoesophageal spasm

PURPOSE Laryngectomized patients with pharyngoesophageal spasm frequently have poor voice quality and dysphagia. Local botulinum toxin A (BTA) injection can relieve muscular hypertonicity and improve symptoms. This procedure should also prolong the functional life span of the tracheoesophageal voice prosthesis. MATERIALS AND METHODS This study evaluates 33 BTA treatments in 11 laryngectomees. All patients were having poor voice quality; 6 patients had additional dysphagia. In 10 patients, the BTA injection has been carried out during rigid pharyngoscopy under general anesthesia. One patient was treated in local anesthesia. RESULTS A subjective improvement of voice quality was reported in 94%. This lasted on average for 20 weeks. The swallowing function improved moderately. For the first time, the functional life span of voice prostheses was examined. After treatment of pharyngoesophageal spasm, their durability was almost tripled. The BTA therapy has a significant effect. CONCLUSIONS The BTA treatment improves voice quality and prolongs functional durability of voice prostheses in laryngectomees with pharyngoesophageal spasm. The success of treatment is of limited duration but can be repeated in the long-term.

Comparison between ABR with click and narrow band chirp stimuli in children

OBJECTIVE Click and chirp-evoked auditory brainstem responses (ABR) are applied for the estimation of hearing thresholds in children. The present study analyzes ABR thresholds across a large sample of childrens ears obtained with both methods. The aim was to demonstrate the correlation between both methods using narrow band chirp and click stimuli. METHODS Click and chirp evoked ABRs were measured in 253 children aged from 0 to 18 years to determine their individual auditory threshold. The delay-compensated stimuli were narrow band CE chirps with either 2000 Hz or 4000 Hz center frequencies. Measurements were performed consecutively during natural sleep, and under sedation or general anesthesia. Threshold estimation was performed for each measurement by two experienced audiologists. RESULTS Pearson-correlation analysis revealed highly significant correlations (r=0.94) between click and chirp derived thresholds for both 2 kHz and 4 kHz chirps. No considerable differences were observed either between different age ranges or gender. Comparing the thresholds estimated using ABR with click stimuli and chirp stimuli, only 0.8-2% for the 2000 Hz NB-chirp and 0.4-1.2% of the 4000 Hz NB-chirp measurements differed more than 15 dB for different degrees of hearing loss or normal hearing. CONCLUSION The results suggest that either NB-chirp or click ABR is sufficient for threshold estimation. This holds for the chirp frequencies of 2000 Hz and 4000 Hz. The use of either click- or chirp-evoked ABR allows a reduction of recording time in young infants. Nevertheless, to cross-check the results of one of the methods, we recommend measurements with the other method as well.

Promising clinical results of an innovative self-crimping stapes prosthesis in otosclerosis surgery.

Objectives This clinical study was performed to retrospectively analyze the hearing improvement of patients with otosclerosis who underwent stapesplasty with a novel nitinol prosthesis in comparison with the use of already established prostheses (titanium and clip prostheses) and to evaluate the suitability of the nitinol prosthesis for ear surgeons with limited experience in otosclerosis surgery. Study Design Retrospective data analysis. Setting Tertiary referral center. Patients Sixty patients who underwent otosclerosis surgery between July 1, 2010, and June 30, 2012, in the ENT department of the University of Munich. Two patients were operated on both sides. For four patients, the stapesplasty was a revision surgery. Interventions Sixty-two procedures of otosclerosis surgery were performed by 6 ear surgeons, one of whom with profound experience in stapesplasty. Main Outcome Measures 1) Postoperative air-bone gap, determined for all surgeons together as well as itemized for the experienced and the nonexperienced stapes surgeons; 2) closure of the air-bone gap in 10 dB bins; and 3) change of high-tone bone-conduction level. Results Pure-tone audiometry documented less postoperative air-bone gap and a higher percentage of air-bone gap closure when using the nitinol prosthesis, especially in comparison with the clip prosthesis. Also, nonexperienced stapes surgeons received better audiometric results when using the novel nitinol prosthesis. Conclusions Clinical evaluation suggests the novel nitinol prosthesis to be a promising tool in otosclerosis surgery for experienced stapes surgeons as well as for ear surgeons with limited experience in stapes surgery.

The Vibrant Soundbridge in Children and Adolescents: Preliminary European Multicenter Results.

Objective Evaluation of safety and efficacy of the Vibrant Soundbridge in the treatment of hearing loss in children and adolescents with primary focus on improvement in speech discrimination. Study Design Prospective, single-subject repeated-measures design in which each subject serves as his/her own control. Setting Tertiary referral center. Patients Nineteen patients aged 5 to 17 years. Intervention Implantation of an active middle ear implant. Main Outcome Measure Improvement in word recognition scores, speech reception thresholds, and signal-to-noise ratios (SNRs) were evaluated, in addition to air and bone conduction. Oldenburger Kids Satztest/Oldenburger Satztest sentences and Göttinger/Freiburger monosyllables at 65-dB hearing level were tested in two age groups. Results Significant speech discrimination improvement was seen in all patients after 6 months. In children 5 to 9 years old, mean monosyllable recognition improved from 28.9% (unaided) to 95.5% (Soundbridge-aided). Aided 50% sentence discrimination at 44.1 dB and SNR of −4.9 dB were measured. In patients 10 to 17 years old, mean word recognition improved from 18.5% to 89.0%, sentence reception threshold improved to 40.2 dB, and SNR to −3.6 dB. Comparison between age groups indicated a slight trend toward quicker adaptation by older subjects. However, after initial adjustment, a higher level of overall benefit was seen at 6 months in younger children. Conclusions Currently, the only middle ear implant approved for pediatric patients, the Vibrant Soundbridge, provides an option in cases of congenital aural atresia or disease-induced defects, when surgical intervention and reconstruction is indicated. The 6-month results in this comparatively large study population validated conclusions found in previous trials.

Funktionelle und ästhetische Rehabilitation der Mikrotie bei Kindern und Jugendlichen

BACKGROUND Microtia leads to a severe functional and aesthetic handicap. Traditionally, the auricle is often reconstructed with cartilage transplants, which is, however, associated with some partially substantial disadvantages. The authors have instead used implants of porous polyethylene for successful ear reconstruction for years, thus, avoiding some of these disadvantages. A significant benefit for the patient is achieved by simultaneous hearing rehabilitation by the implantation of active middle ear prostheses. METHODS The authors present their surgical concept which allows functional and aesthetic rehabilitation of microtia in children and adolescents in a single operation. In the respective patient collective, audiometric measurements in quiet and noisy environments were conducted pre- and postoperatively, and health-related quality of life was determined using a validated questionnaire. RESULTS All patients experienced a substantial hearing gain both in quiet and noisy environments. The evaluation of health-related quality of life showed a significant benefit from the intervention. CONCLUSION Functional and aesthetic rehabilitation of microtia with active middle ear implants and ear reconstruction using porous polyethylene leads to good and reliable long-term results and can increase the health-related quality of life of affected children and adolescents. The main advantage of this concept is the possibility of a single procedure.