Differences in the swallowing process of newborns and healthy preterm infants: first results with a non-invasive bioimpedance and electromyography measurement system.

PURPOSE: Preterm infants (PI) have difficulty coordinating sucking, swallowing and breathing, and there is a risk of aspiration. The causes of this are not yet sufficiently understood. The aim of this study was to test a novel measurement device to measure breathing and pharyngeal processes involved in swallowing externally in everyday life to identify possible differences in neonates (NB) and PI. METHODS: Forty healthy NB were studied at 4-8 weeks of age (mean: 6.7 weeks) and 20 healthy PI (mean gestational age 30.5 weeks) at postmenstrual age (PMA) 34/35 weeks (mean PMA 35.1 weeks) during a single feeding. Surface electrodes were used to measure bioimpedance and electromyography reflecting swallow-related changes in the pharynx and muscle activation of the tongue and submental muscles. A respiratory belt was combined with recording of the depth of chest movements and the occurrence of pauses in breathing. RESULTS: Velocity and extent of pharyngeal closure did not differ significantly across the feeding period (velocity: p=0.09, closure: p=0.17), but during the first two suck-swallow bursts PI had greater velocity (p<0.001*) and extent of pharyngeal closure (p=0.004*) than NB. The duration of swallowing phases was significantly longer in PIs (p<0.001*), their muscle activation decreased faster (p<0.001*), and they had more pauses in breathing than NBs. CONCLUSIONS: The novel measurement device allowed, for the first time in everyday life, the measurement of factors influencing swallowing and breath-swallow coordination in NBs and PIs. PIs showed differences from NBs most likely due to differences in muscle strength and condition.

Can hearing amplification improve presbyvestibulopathy and/or the risk-to-fall ?

PURPOSE: The decline of sensory systems during aging has been widely investigated and several papers have correlated the visual, hearing and vestibular systems and the consequences of their functional degeneration. Hearing loss and presbyvestibulopathy have been found to be positively correlated as is with the risk-to-fall. MATERIAL AND METHODS: The present study was therefore designed as systematic review (due to PRISMA criteria) which should correlate hearing amplification by hearing aids and/or cochlear implants with balance outcome. However, the literature review (Cochrane, PubMed) revealed ten paper (prospective, controlled trials and acute trials) with heterogenous patient popiulations and non-uniform outcome measures (i.e., gait analysis, questionnaires, postural stabilometry) so that no quantitative, statistical analysis could be performed. RESULTS: The qualitative analysis oft he identified studies showed that hearing amplification in the elderly improves spatio-temporal orientation (particularly with cochlear implants) and that the process of utilizing auditory information for balance control takes some time (i.e., the neuroplasticity-based, learning processes), usually some months in cochlear implantees. DISCUSSION: Hearing and balance function degenerate independently from each other and large interindividual differences require a separate neurotological examination of each patient. However, hearing amplification is most helpful to improve postural stability, particularly in the elderly. Future research should focus on controlled, prospective clinical trials where a standardized test battery covering the audiological and neurotological profile of each elderly patient pre/post prescription of hearing aids and/or cochlear implantation should be followed up (for at least 1 year) so that also the balance improvements and the risk-to-fall can be reliably assessed (e.g., by mobile posturography and standardized questionnaires, e.g., the DHI).

Comparison of a Mid Scala and a Perimodiolar Electrode in Adults: Performance, Impedances, and Psychophysics.

OBJECTIVES: The HiFocus Mid-Scala electrode array (HFms) is designed to sit within the scala tympani without touching either the lateral wall or the modiolus. The aim of this study was to compare the HFms to the Helix perimodiolar electrode array. METHOD: Two groups of recipients with Helix (n = 22 ears) and HFms (n = 29 ears) electrode arrays were retrospectively identified and matched by age at implantation and duration of severe to profound deafness. Most comfortable listening levels (M), impedances, Freiburger Monosyllables in quiet, and Oldenburg sentences in adaptive noise were compared at 3, 6, and 12 months postimplant. RESULTS: Median scores for monosyllables in quiet for the HFms group were significantly better than the Helix group at each test interval (p < 0.05). Speech perception in quiet also significantly improved from 3 to 12 months for both groups (p < 0.001). There was no significant difference between the groups for speech in noise. Impedances were significantly lower for the HFms group at 12 months (p < 0.05) except at the basal end and M levels were generally higher. CONCLUSIONS: The HFms group had better median performance for monosyllables in quiet than the Helix group at each test interval, although performance in noise was similar. For speech in noise, the HFms group appear to reach optimum performance quicker than the Helix group. Impedances were lower in the HFms group across the array, other than at the most basal end, and support our hypothesis that the HFms assumes a more lateral position within the cochlea than the Helix electrode, although our article did not include imaging data.

Predictable swallowing function after open horizontal supraglottic partial laryngectomy.

OBJECTIVE: After horizontal supraglottic partial laryngectomy, patients have an increased risk of dysphagia as they are not able to close the laryngeal entrance during swallowing, especially if the surgical defect of the tongue base has increased. There is no investigation that studies risk factors for impaired swallow function, or that predicts postoperative swallow outcomes based on radiologically determined tumor dimensions. The present study investigated the impact of the tongue base tumor extension (determined by CT scan in patients undergoing partial laryngectomy) on the recovery rate of swallow function. METHODS: The retrospective study in a tertiary hospital between 2000 and 2015 included all patients who underwent open horizontal supraglottic partial laryngectomy due to oropharyngeal cancer of the tongue base, or supraglottic laryngeal cancer with tongue base infiltration. All clinicopathological data were collected. The dimension of tongue base infiltration was measured using CT scan. Swallow function was recorded by Fiberoptic Endoscopic Evaluation of Swallowing and determined by evaluating both the duration until nasogastric tube removal and changing of the cuffed tracheostomy tube for an uncuffed speech cannula. RESULTS: The study included 26 patients (44-76 years, median 59 years). The clinical tumor (cT) classification included cT2 and cT3, while the pathologic tumor (pT) classification included pT2 and pT3 in 90% and pT1 and pT4 in 10% respectively. The duration until using the speech cannula was not associated with clinicopathological data, including the investigated radiologic tumor dimensions (biggest tumor diameter, tongue base infiltration depth, width, height, area and volume). The duration until nasogastric tube removal was significantly associated with the tongue base infiltration width (p=0.012), height (p=0.026) and area (p<0.0001). The patients were divided into two groups according to the median tongue base infiltration area estimated as 6.20cm(2). In patients <6.20cm(2), 50% of the nasogastric tubes were removed after 4 days (95% CI 0-8.6 days) and in patients ≥6.20cm(2), 50% were removed after 22 days (95% CI 6.8-37.2 days; p<0.0001). CONCLUSION: The postoperative swallow function after open horizontal supraglottic partial laryngectomy depends on the tumor extension of the tongue base. The tongue base infiltration area is a useful tool for surgical planning as it can be used to predict postoperative swallow function. In foreseeably permanent dysphagia, as well as permanent and necessary tracheotomy tube cuffs after organ-preserving surgery, alternative therapy methods should be particularly preferred as the primary chemoradiation.

Efficacy of EMG/Bioimpedance-Triggered Functional Electrical Stimulation on Swallowing Performance.

In order to support swallowing, the efficacy of functional electrical stimulation for different stimulation settings of the submental musculature has been investigated. The stimulation was administrated at rest and synchronously to voluntary initiated swallows. The onset of a swallow was detected in real-time by a combined electromyography/ bioimpedance measurement at the neck in order to trigger the stimulation. The amplitude and speed of larynx elevation caused by the FES has been assessed by the observed change in bioimpedance whereas a reduction of bioimpedance corresponds to an increase in larynx elevation. Study results from 40 healthy subjects revealed that 73% of the subjects achieved a larger and faster larynx elevation during swallowing with triggered FES and therefor a better protection of their airways. However, we also observed a decrease in larynx elevation compared to normal swallowing in 11 out of the 40 subjects what might not benefit from such a treatment. The largest improvement of larynx elevation and speed during swallowing could be achieved with three stimulation channels formed by four electrodes in the submental region.

Multisensor Classification System for Triggering FES in Order to Support Voluntary Swallowing.

In dysphagia the ability of elevating the larynx and hyoid is usually impaired. Electromyography (EMG) and Bioimpedance (BI) measurements at the neck can be used to trigger functional electrical stimulation (FES) of swallowing related muscles. Nahrstaedt et al.1 introduced an algorithm to trigger the stimulation in phase with the voluntary swallowing to improve the airway closure and elevation speed of the larynx and hyoid. However, due to non-swallow related movements like speaking, chewing or head turning, stimulations might be unintentionally triggered. So far a switch was used to enable the BI/EMG-triggering of FES when the subject was ready to swallow, which is inconvenient for practical use. In this contribution, a range image camera system is introduced to obtain data of head, mouth, and jaw movements. This data is used to apply a second classification step to reduce the number of false stimulations. In experiments with healthy subjects, the amount of potential false stimulations could be reduced by 47% while 83% of swallowing intentions would have been correctely supported by FES.

Breathing-synchronised electrical stimulation of the abdominal muscles in patients with acute tetraplegia: A prospective proof-of-concept study.

OBJECTIVE: To examine whether, by enhancing breathing depth and expectoration, early use of breathing-synchronised electrical stimulation of the abdominal muscles (abdominal functional electrical stimulation, AFES) is able to reduce pulmonary complications during the acute phase of tetraplegia. DESIGN: Prospective proof-of-concept study. SETTING: Spinal cord unit at a level 1 trauma center. METHOD: Following cardiovascular stabilisation, in addition to standard treatments, patients with acute traumatic tetraplegia (ASIA Impairment Scale A or B) underwent breathing-synchronised electrical stimulation of the abdominal muscles to aid expiration and expectoration. The treatment was delivered in 30-minute sessions, twice a day for 90 days. The target was for nine of 15 patients to remain free of pneumonia meeting Centers for Disease Control and Prevention (CDC) diagnostic criteria. RESULTS: Eleven patients were recruited to the study between October 2011 and November 2012. Two patients left the study before completion. None of the patients contracted pneumonia during the study period. No complications from electrical stimulation were observed. AFES led to a statistically significant increase in peak inspiratory and expiratory flows and a non-statistically significant increase in tidal volume and inspiratory and expiratory flow. When surveyed, 6 out of 9 patients (67%) reported that the stimulation procedure led to a significant improvement in breathing and coughing. CONCLUSION: AFES appears to be able to improve breathing and expectoration and prevent pneumonia in the acute phase of tetraplegia (up to 90 days post-trauma). This result is being validated in a prospective multicentre comparative study.

Association of Oversized Tracheal Tubes and Cuff Overinsufflation With Postintubation Tracheal Ruptures.

OBJECTIVES: Postintubation tracheal ruptures (PTR) are rare but cause severe complications. Our objective was to investigate the tracheal pattern of injury resulting from cuff inflation of the tracheal tube, to study the two main factors responsible for PTR (cuff overinsufflation and inapplicable tube sizes), and to explain the context, why small women are particularly susceptible to PTR. METHODS: Experimental study performed on 28 fresh human laryngotracheal specimens (16 males, 12 females) within 24 hours post autopsy. Artificial ventilation was simulated by using an underwater construction and a standard tracheal tube. Tube sizes were selected according to our previously published nomogram. Tracheal lesions were detected visually and tracheal diameters measured. The influence of body size, sex difference and appropriate tube size were investigated according to patient height. RESULTS: In all 28 cases, the typical tracheal lesion pattern was a longitudinal median rupture of the posterior trachea. Appropriate tube sizes according to body size caused PTR with significantly higher cuff pressure when compared with oversized tubes. An increased risk of PTR was found in shorter patients, when oversized tubes were used. Sex difference did not have any significant influence. CONCLUSION: This experimental model provides information about tracheal patterns in PTR for the first time. The model confirms by experiment the observations of case series in PTR patients, and therefore emphasizes the importance of correct tube size selection according to patient height. This minimizes the risk of PTR, especially in shorter patients, who have an increased risk of PTR when oversized tubes are used.

Airway complications in traumatic lower cervical spinal cord injury: A retrospective study.

OBJECTIVE: To investigate risk factors for pneumonia in patients with traumatic lower cervical spinal cord injury. DESIGN: Observational study, retrospective study. SETTING: Spinal cord unit in a maximum care hospital. METHODS: Thirty-seven patients with acute isolated traumatic spinal cord injury at levels C4-C8 and complete motor function injury (AIS A, B) treated from 2004 to 2010 met the criteria for inclusion in our retrospective analysis. The following parameters were considered: ventilation-specific parameters, re-intubation, creation of a tracheostomy, pneumonia, antibiotic treatment, and length of intensive care unit (ICU) stay and total hospitalization. RESULTS: Among the patients, 81% had primary invasive ventilation. In 78% of cases a tracheostomy was created; 3% of these cases were discharged with invasive ventilation and 28% with a tracheostomy without ventilation. Pneumonia according to Centers for Disease Control criteria occurred in 51% of cases within 21±32 days of injury, and in 3% at a later date. The number of pre-existing conditions was significantly associated with pneumonia. Length of ICU stay was 25±34 days, and average total hospital duration was 230±144 days. Significant factors affecting the duration of ventilation were the number of pre-existing conditions and tetraplegia-specific complications. CONCLUSIONS: Our results confirm that patients with traumatic lower cervical spinal cord injuries defined by lesion level and AIS constitute a homogeneous group. This group is characterized by a high rate of pneumonia during the first 4 weeks after injury. The number of pre-existing general conditions and spinal injury-specific comorbidities are the only risk factors identified for the development of pneumonia and/or duration of ventilation.

Automated detection and evaluation of swallowing using a combined EMG/bioimpedance measurement system.

INTRODUCTION: Developing an automated diagnostic and therapeutic instrument for treating swallowing disorders requires procedures able to reliably detect and evaluate a swallow. We tested a two-stage detection procedure based on a combined electromyography/bioimpedance (EMBI) measurement system. EMBI is able to detect swallows and distinguish them from similar movements in healthy test subjects. STUDY DESIGN: The study was planned and conducted as a case-control study (EA 1/019/10, and EA1/160/09, EA1/161/09). METHOD: The study looked at differences in swallowing parameters in general and in the event of penetration during swallows in healthy subjects and in patients with an oropharyngeal swallowing disorder. A two-stage automated swallow detection procedure which used electromyography (EMG) and bioimpedance (BI) to reliably detect swallows was developed. RESULTS: Statistically significant differences between healthy subjects and patients with a swallowing disorder were found in swallowing parameters previously used to distinguish between swallowing and head movements. Our two-stage algorithm was able to reliably detect swallows (sensitivity = 96.1%, specificity = 97.1%) on the basis of these differences. DISCUSSION: Using a two-stage detection procedure, the EMBI measurement procedure is able to detect and evaluate swallows automatically and reliably. The two procedures (EMBI + swallow detection) could in future form the basis for automated diagnosis and treatment (stimulation) of swallowing disorders.

Multi-stage surgery for airway patency after metallic stent removal in benign laryngotracheal airway disease in two adolescents.

Laryngotracheal stents may damage the highly complex laryngeal structures, impair voice and swallowing functions and cause tissue ingrowths, thereby necessitating airway patency interventions. In benign airway disease, the number of adolescents with laryngotracheal stents is therefore limited. We present two cases of laryngeal metallic stent placement following benign airway disease. Two adolescents presented with severe dyspnea and self-expandable metallic stent placement after benign laryngotracheal stenoses. Granulation tissue ingrowths required additional surgical interventions every 6-8 weeks to recanalize the stent lumen. We performed multi-stage surgery including removal of the embedded stent, segmental resection of the stenotic area, end-to-end-anastomosis and laryngotracheal reconstruction respectively, to achieve patent airway without tracheal cannulation. Montgomery T-tubes were temporarily inserted to bridge the complex reconstructions. In both adolescents, we achieved successful removal of the embedded stent and patent airway. Bilateral vocal fold paralysis required additional surgery to improve the final airway patency and vocal rehabilitation. Stent removal, segmental resection and laryngotracheal reconstruction provide the achievement of patent airway and allow decannulation. Temporary Montgomery T-tubes bridge complex laryngotracheal reconstructions. In benign laryngeal airway disease, stent placement should be avoided, especially in adolescents. Transfer to a specialist center should be considered prior to metallic stent implantation. In general, self-expanding tracheobronchial stents can be placed in selected patients where surgical interventions are limited.

Evaluation of an EMG bioimpedance measurement system for recording and analysing the pharyngeal phase of swallowing.

A neuroprosthetic device for treating swallowing disorders requires an implantable measurement system capable to analysing the timing and quality of the swallowing process in real time. A combined EMG bioimpedance (EMBI) measurement system was developed and is evaluated here. The study was planned and performed as a case-control study. The studies were approved by the Charité Berlin ethics committee in votes EA1/160/09 and EA1/161/09. Investigations were carried out on healthy volunteers in order to examine the usefulness and reproducibility of measurements, the ability to distinguish between swallowing and head movements and the effect of different food consistencies. The correlation between bioimpedance and anatomical and functional changes occurring during the pharyngeal phase of swallowing in non-healthy patients was examined using videofluoroscopy (VFSS). 31 healthy subjects (15♂, 16♀) were tested over the course of 1350 swallows and 19 (17♂, 2♀) non-healthy patients over the course of 54 swallows. The signal curves obtained from both transcutaneous and subcutaneous measurement were similar, characteristic and reproducible (r > 0.5) and correlated with anatomical and functional changes during the pharyngeal phase of swallowing observed using VFSS. Statistically significant differences between head movements and swallowing movements, food volumes and consistencies were found. Neither the conductivity of the food, the sex of the test subject nor the position of the measurement electrodes exerted a statistically significant effect on the measured signal. EMBI is able to reproducibly map the pharyngeal phase of swallowing and changes associated with it both transcutaneously and subcutaneously. The procedure therefore appears to be suitable for use in performing automated evaluation of the swallowing process and for use as a component of an implant.

Sound-induced vertigo after cochlear implantation.

AIM: Postoperative vertigo is a well-known complication after cochlear implantation. The aim of the study was to investigate whether the electrical stimulation of the auditory structures via cochlear implant electrodes can affect the vestibular system and induce vertigo. MATERIALS AND METHODS: In the first group, 114 patients were surveyed retrospectively via questionnaires to evaluate the occurrence and frequency of sound-induced vertigo after cochlear implantation. In the second group of 26 patients, the effects of electrical stimulation on the vestibular system were studied prospectively. RESULTS: In the first group of patients without any preoperative sound-induced vertigo (n = 104), 20 patients (18%) reported sound-induced vertigo, which occurred after cochlear implantation. In the second group, an acoustic stimulus delivered via the speech processor of the cochlear implant elicited a vestibular evoked myogenic potential response in 4 of the 26 patients as a sign of vestibular costimulation (of the macula sacculi as part of the otolith organs). Horizontal and vertical nystagmus was triggered, whereas utricular function and postural stability remained unchanged. No correlation was found between C/M levels and the vestibular evoked myogenic potentials and nystagmus responses. CONCLUSION: Sound-induced vertigo can occur in cochlear implantees. This seems to be primarily caused by electrical costimulation of the sacculus as part of the otolith organs.

The effect of pulling out cochlear implant electrodes on inner ear microstructures: a temporal bone study.

The exchange of an cochlear implant or the re-positioning of an electrode have become more frequently required than a decade ago. The consequences of such procedures at a microstructural level within the cochlea are not known. It was the aim of the present study to further investigate the effects of an CI electrode pull-out. Therefore 10 freshly harvested temporal bones (TB) were histologically evaluated after a cochlear implant electrode pull-out of a perimodiolar electrode. In additional 9 TB the intrascalar movements of the CI electrode while being pulled-out were digitally analysed by video- capturing. Histologically, a disruption of the modiolar wall or the spiral osseous lamina were not observed. In one TB, a basilar membrane lifting up was found, but it could not be undoubtedly attributed to the pull-out of the electrode. When analyzing the temporal sequence of the electrode movement during the pull-out, the electrode turned in one case so that the tip elevates the basilar membrane. The pull- out of perimodiolarly placed CI electrodes does not damage the modiolar wall at a microstructural level and should be guided (e.g., forceps) to prevent a 90 o turning of the electrode tip into the direction of the basilar membrane.

The semisolid bolus swallow test for clinical diagnosis of oropharyngeal dysphagia: a prospective randomised study.

Contrary to clinical experience, clinical swallow tests are predominantly performed using water (water swallow tests, WST). In this study, we examine whether swallow tests performed using a bolus of semisolid food (bolus swallow test, BST) offer benefits. In a prospective, randomised, blind study, the results of a standardised saliva swallow test (SST), WST, BST, combinations of these tests and an endoscopic swallow test (FEES) in patients with oropharyngeal swallowing disorders of neurological (NEU) and non-neurological (NNEU) origin were compared. Sensitivity, specificity, test accuracy and inter-rater reliability were analysed. 62 patients (mean age = 64.68; range = 22-84) were included in the study (NEU = 40; NNEU = 22). A sensitivity of 70.7% (NEU = 70.3%, NNEU = 71.4%) and specificity of 82.5% (NEU = 92.3%; NNEU = 100%) were determined for the WST. The BST + SST was found to have a sensitivity of 89.6% (NEU = 66.7%; NNEU = 90.9%) and a specificity of 72.7% (NEU = 87.5%; NNEU = 90.9%). Analysis of test accuracy showed a statistically significant correlation between FEES and BST + SST. Only BST + SST exhibited statistically significant inter-rater reliability. BST in combination with SST was the sensitive clinical instrument for detecting aspiration both over the patient population as a whole and over the two sub-populations. Inter-rater reliability was found to be statistically significant. The results presented here demonstrate the benefit of semisolid food in investigating clinical dysphagia.

Selection and placement of oral ventilation tubes based on tracheal morphometry.

OBJECTIVE/HYPOTHESIS: Evidence-based guidelines for the selection of appropriately sized ventilation tubes as well as their placement do not exist, although iatrogenic injuries to the trachea and larynx following endotracheal intubation are not infrequent. Our objective was to provide selection recommendations for ventilation tubes based on anatomic criteria. STUDY DESIGN: Prospective cross-sectional study at a tertiary care hospital. METHODS: From January 2010 to June 2010 all patients more than 16 years who underwent computer tomography of the neck were included. Contraindications were intubation, tracheotomy, fractures of the lower jaw, tumors, and head or neck deformities. Radiologic data was used to determine the distance between the lower incisors and cricoid cartilage and the smallest laryngotracheal diameter. The results were correlated with patient characteristics and compared with properties of ventilation tubes. RESULTS: One hundred fifty-nine patients were included in the study. The laryngotracheal constriction was subcricoidal with a mean diameter of 15.5 ± 3.2 mm coronal and 17.1 ± 2.6 mm sagittal. The mean distance between lower incisors and cricoid cartilage was 176.5 ± 14.8 mm. Patient height correlated significantly with the coronal subcricoid tracheal diameter (r = .51; P < .001) as well as with the distance between lower incisors and cricoid cartilage (r = .64; P < .001). No statistically significant gender or age-related correlations were found. Despite having the same specifications, tubes from different manufacturers differed considerably in their dimensions. CONCLUSIONS: Selection of size and placement of ventilation tubes can be based on patient height. Considerable differences in the dimensions of ventilation tubes necessitate a height-based nomogram for evidence-based tube selection and placement. A uniform system of tube labeling based on biometric data is required.

Pseudarthroses of the cornu of the thyroid cartilage.

OBJECTIVE: Injuries to the cartilaginous larynx are rare disorders that usually undergo good spontaneous healing and rarely require surgery. STUDY DESIGN: Case series with chart review from patients with pseudarthrosis of the cornu of the thyroid cartilage. SETTING: ENT department of a level I trauma center. SUBJECTS AND METHODS: We examined the medical records of seven patients treated for impaired healing of the cornu of the thyroid cartilage at a level I trauma center between 1997 and 2009. RESULTS: Seven patients were treated as a result of impaired healing of injuries to the cornu of the thyroid cartilage caused by trivial trauma (e.g., car accidents). The principal symptom was odynophagia. Computed tomography was used to confirm the diagnosis. Treatment involved resecting the cornu of the thyroid cartilage. Histology showed a hypertrophic pseudarthrosis at the base of the cornu. All patients were free of symptoms 10 days after resection. CONCLUSION: Pseudarthrosis of the cornu of the thyroid cartilage is a previously undescribed condition. Pseudarthrosis of the laryngeal skeleton should be excluded in patients with odynophagia.

Vestibular and taste disorders after bilateral cochlear implantation.

The objective of this study was to investigate the occurrence of vestibular receptor deficiency and taste disorders after bilateral cochlear implantation in postlingually deafened patients and to find out whether the risk for these complications is higher for the second implantation. In a retrospective cohort study, we examined 20 patients (11-58 years, mean age 41.5 years), implanted sequentially between 2000 and 2007 (mean period between cochlear implantation 32.9 ± 25 months). Pre- and postoperative vestibular testing was performed by subjective rating [Dizziness Handicap Inventory (DHI)], caloric irrigation [vestibuloocular reflex (VOR)] and by vestibular-evoked myogenic potential (VEMP) recordings for saccular function. The sense of taste was evaluated pre- and postoperatively by a questionnaire and testing (sour/sweet/bitter/salty bilaterally on the tongue). DHI evaluation showed a moderate not significant mean increase by 2.7 ± 7.7 SD points after the first and a significant increase by 9.4 ± 16.6 SD points after the second implantation. Ipsilateral VEMP responses disappeared in three ears (27.3%) after the first and in two ears (18.2%) after the second operation. VOR disappeared only once (5.9%) after the first implantation. One (5%) patient complained of a persisting disturbance of taste in the questionnaire after unilateral and 3 (15%) after bilateral implantation. Specific testing showed in one case (5%) a unilateral taste disorder after ipsilateral cochlear implantation. Our data show that there is a higher risk for subjective vertigo after the second implantation. The occurrence of unilateral and/or bilateral vestibular dysfunction and the potential risk of taste disorder should be included in the risk counseling before bilateral cochlear implantation to increase patients' and medicolegal safety in the decision-making process.

Airway management in acute tetraplegics: a retrospective study.

The objective of this study was to develop an evidence-based airway management protocol for patients with acute tetraplegia. The method consisted of an analysis of the medical records of patients (September 1997-December 2002) with a spinal cord injury and a neurological deficit less than 8 weeks old. Of the 175 patients, 72 (41, 14%) were tracheotomised. This was influenced by the origin of the paralysis, Frankel score, and number of cervical spine operations, accompanying injuries and accompanying illnesses. Tracheotomy did not affect the duration of treatment, duration of ventilation or length of stay in the intensive care unit. The need for a tracheotomy was able to be predicted in 73.31% with neurological level, Frankel score and severity of accompanying injuries. In patients with acute tetraplegia, primary tracheotomy is indicated in sub C1-C3 with Frankel stage A/B, sub C4-C6 with Frankel stage A/B with trauma and accompanying injuries/accompanying illnesses, and in patients with complex cervical spine trauma that requires a combined surgical approach. In other patients, an attempt at extubation should be made.