The ototoxic potential of cobalt from metal-on-metal hip implants: a pilot study on the patient-reported auditory, vestibular, and general neurological outcome.

OBJECTIVE: This study aimed to systematically investigate the ototoxic potential of cobalt in patients with a metal-on-metal (MoM) hip implant, using objective auditory and vestibular assessments and a questionnaire. The results of the objective evaluation were published previously, whereas the current study focused on the questionnaire outcome and its relationship to the blood cobalt level. Design and study sample: Twenty patients (33-65 years) with a primary MoM hip implant and 20 non-implanted control subjects, matched for age, gender, and noise exposure, received a questionnaire to evaluate the presence of several hearing and balance symptoms (part 1) and general neurological issues (part 2). RESULTS: Concerning part 1, the proportion of auditory-related symptoms in general (p = 0.022) and tinnitus (p = 0.047) was significantly higher in the MoM patient group, whereas no group difference was found for hyperacusis, increased listening effort, and decreased speech understanding. Concerning part 2, no significant group differences were detected. Within the MoM patient group, the questionnaire outcome was not significantly different between the low-exposure and high-exposure subgroups according to the blood Co level. CONCLUSIONS: In line with our previous study, these results potentially imply Co-induced impairment to the auditory system, despite the lack of a clear dose-response relationship.

Pilot study on patients with Mal de Debarquement syndrome during pregnancy.

AIM: To evaluate if patients with Mal de Debarquement syndrome (MdDS) demonstrate different symptom levels or symptom type during pregnancy. MATERIALS & METHODS: 18 MdDS patients that were or had been pregnant during their condition were recruited to complete a retrospective online questionnaire. Respondents answered questions regarding their basic clinical data, diagnosis, triggers and differences in symptom level and symptom type during pregnancy and before pregnancy. RESULTS: A total of 81.3% reported that their symptoms were reduced during pregnancy compared with before pregnancy. Respondents also reported a different perception of motion and experienced less dizziness while being pregnant. CONCLUSION: The physiological changes that occur during pregnancy improve the symptoms of patients with MdDS, and this is potentially attributable to the rise in estrogen and progesterone.

'Standard' versus 'nose reference' electrode placement for measuring oVEMPs with air-conducted sound: Test-retest reliability and preliminary patient results.

OBJECTIVES: This study compared two electrode placements ('standard' versus 'nose reference' placement) for measuring oVEMPs, elicited by air-conducted 500Hz tone bursts. The test-retest reliability of both positions was evaluated and additionally both electrode placements were applied on a group of vestibular patients. METHODS: Eighteen healthy volunteers (range of 20-25years) participated in the first part and were retested after one week for evaluation of the test-retest reliability. Eleven patients (range of 41-74years) with a variety of vestibular pathologies were tested once. RESULTS: In the normal group, the nose reference electrode placement resulted in significantly larger peak-to-peak amplitudes (p<0.001), shorter n10 (p=0.001) and p15 (p<0.001) latencies and smaller 95% prediction intervals for the Inter-Ocular Ratio (IOR) ([-68, 68] for the standard position versus [-32, 32] for the nose reference position). Furthermore, an excellent amplitude and IOR test-retest reliability was observed with the nose reference configuration, as shown by the intraclass correlation coefficient (ICC), the coefficient of variation of the method error (CVME) and the minimal detectable differences (MDD). In the patient group, the same significant amplitude difference was found. Moreover, three patients presented with absent oVEMPs when recorded with the standard placement, whereas the nose reference placement could evoke a detectable oVEMP response. CONCLUSIONS: This study demonstrated that a nose reference electrode position results in larger oVEMP amplitudes and achieves a better reliability for the most important clinical parameters (amplitude and IOR). Our patient data substantiate the possible clinical benefit of this position, but further systematic patient verification is required. SIGNIFICANCE: The nose reference electrode position facilitates the detection of generally very small oVEMP responses and shows a high test-retest reliability, showing promising potential for future use in the vestibular clinic.

Comparison of Different Electrode Configurations for the oVEMP With Bone-Conducted Vibration.

OBJECTIVES: This study was performed to compare three electrode configurations for the ocular vestibular evoked myogenic potentials (oVEMPs)-"standard," "sternum," and "nose"-by making use of bone-conducted stimuli (at the level of Fz with a minishaker). In the second part, we compared the test-retest reliability of the standard and nose electrode configuration on the oVEMP parameters. DESIGN: This study had a prospective design. Fourteen healthy subjects participated in the first part (4 males, 10 females; average age = 23.4 (SD = 2.6) years; age range 19.9 to 28.3 years) and second part (3 males, 11 females; average age = 22.7 (SD = 2.4) years; age range 20.0 to 28.0 years) of the study. OVEMPs were recorded making use of a hand-held bone conduction vibrator (minishaker). Tone bursts of 500 Hz (rise/fall time = 2 msec; plateau time = 2 msec; repetition rate = 5.1 Hz) were applied at a constant stimulus intensity level of 140 dB FL. RESULTS: PART 1: The n10-p15 amplitude obtained with the standard electrode configuration (mean = 15.8 µV; SD = 6.3 µV) was significantly smaller than the amplitude measured with the nose (Z = -3.3; p = 0.001; mean = 35.0 µV; SD = 19.1 µV) and sternum (Z = -3.3; p = 0.001; mean = 27.1 µV; SD = 12.2 µV) electrode configuration. The p15 latency obtained with the nose electrode configuration (mean = 14.2 msec; SD = 0.54 msec) was significantly shorter than the p15 latency measured with the standard (Z = -3.08; p = 0.002) (mean = 14.9 msec; SD = 0.75 msec) and sternum (Z = -2.98; p = 0.003; mean = 15.4 msec; SD = 1.07 msec) electrode configuration. There were no differences between the n10 latencies of the three electrode configurations. The 95% prediction intervals (given by the mean ± 1.96 * SD) for the different interocular ratio values were [-41.2; 41.2], [-37.2; 37.2], and [-25.9; 25.9] for standard, sternum, and nose electrode configurations, respectively. PART 2: Intraclass correlation (ICC) values calculated for the oVEMP parameters obtained with the standard electrode configuration showed fair to good reliability for the parameters n10-p15 amplitude (ICC = 0.51), n10 (ICC = 0.52), and p15 (ICC = 0.60) latencies. The ICC values obtained for the parameters acquired with the nose electrode configuration demonstrated a poor reliability for the n10 latency (ICC = 0.37), a fair to good reliability for the p15 latency (ICC = 0.47) and an excellent reliability for the n10-p15 amplitude (ICC = 0.85). CONCLUSIONS: This study showed the possible benefits from alternative electrode configurations for measuring bone-conducted-evoked oVEMPs in comparison with the standard electrode configuration. The nose configuration seems promising, but further research is required to justify clinical use of this placement.

"SO STONED": Common Sense Approach of the Dizzy Patient.

The history taking of a dizzy patient is of utmost importance in order to differentiate the possible etiologies of vertigo. The key factors that allow a first approximation of diagnosis identification are based on the time profile, symptom profile, and trigger profile of the disease. Here, the proposed mnemonic "SO STONED" comprises eight different dimensions that characterize the vertigo-related complaints of the patient and guide the clinician in his or her decision scheme. All the letters "SO STONED" have a specific meaning: Symptoms, Often (Frequency), Since, Trigger, Otology, Neurology, Evolution, and Duration. Since the most common vestibular diseases have different fingerprints when all dimensions are considered, this tool can facilitate the identification of the appropriate vestibular diagnosis.

The Effect of Optokinetic Stimulation on Perceptual and Postural Symptoms in Visual Vestibular Mismatch Patients.

BACKGROUND: Vestibular patients occasionally report aggravation or triggering of their symptoms by visual stimuli, which is called visual vestibular mismatch (VVM). These patients therefore experience discomfort, disorientation, dizziness and postural unsteadiness. OBJECTIVE: Firstly, we aimed to get a better insight in the underlying mechanism of VVM by examining perceptual and postural symptoms. Secondly, we wanted to investigate whether roll-motion is a necessary trait to evoke these symptoms or whether a complex but stationary visual pattern equally provokes them. METHODS: Nine VVM patients and healthy matched control group were examined by exposing both groups to a stationary stimulus as well as an optokinetic stimulus rotating around the naso-occipital axis for a prolonged period of time. Subjective visual vertical (SVV) measurements, posturography and relevant questionnaires were assessed. RESULTS: No significant differences between both groups were found for SVV measurements. Patients always swayed more and reported more symptoms than healthy controls. Prolonged exposure to roll-motion caused in patients and controls an increase in postural sway and symptoms. However, only VVM patients reported significantly more symptoms after prolonged exposure to the optokinetic stimulus compared to scores after exposure to a stationary stimulus. CONCLUSIONS: VVM patients differ from healthy controls in postural and subjective symptoms and motion is a crucial factor in provoking these symptoms. A possible explanation could be a central visual-vestibular integration deficit, which has implications for diagnostics and clinical rehabilitation purposes. Future research should focus on the underlying central mechanism of VVM and the effectiveness of optokinetic stimulation in resolving it.

Mal de debarquement syndrome: a systematic review.

Mal de debarquement (MdD) is a subjective perception of self-motion after exposure to passive motion, in most cases sea travel, hence the name. Mal de debarquement occurs quite frequently in otherwise healthy individuals for a short period of time (several hours). However, in some people symptoms remain for a longer period of time or even persist and this is then called mal de debarquement syndrome (MdDS). The underlying pathogenesis is poorly understood and therefore, treatment options are limited. In general, limited studies have focused on the topic, but the past few years more and more interest has been attributed to MdDS and its facets, which is reflected by an increasing number of papers. Till date, some interesting reviews on the topic have been published, but a systematic review of the literature is lacking and could help to address the shortcomings and flaws of the current literature. We here present a systematic review of MdD(S) based on a systematic search of medical databases employing predefined criteria, using the terms "mal de debarquement" and "sea legs". Based on this, we suggest a list of criteria that could aid healthcare professionals in the diagnosis of MdDS. Further research needs to address the blank gaps by addressing how prevalent MdD(S) really is, by digging deeper into the underlying pathophysiology and setting up prospective, randomized placebo-controlled studies to evaluate the effectiveness of possible treatment strategies.

Cochlear implants in children deafened by congenital cytomegalovirus and matched Connexin 26 peers.

OBJECTIVE: To compare the long-term speech perception and production outcomes after cochlear implantation (CI) in children deafened by congenital cytomegalovirus (cCMV) with a matched group of Cx26-CI children by controlling for chronological age and magnetic resonance imaging (MRI) findings. METHODS: Retrospective review of 12 cCMV-CI children and matched Cx26-CI children for speech perception and speech production outcomes. RESULTS: Two trends were seen in our data. First, cCMV-CI children with normal MRI scans perform equally or even slightly better on speech perception tests compared to their Cx26-CI peers during the first three years. The majority of cCMV-CI children with normal MRI scans (5 out of 7), suffered from a delayed-onset SNHL. Their mean age at first implantation (2y9m, range 15-82m) was higher compared to their matched Cx26 peers (9m, range 7-12m). Before being implanted, the majority of these delayed-onset hearing impaired children had benefited from a certain period of normal hearing (with or without amplification of a hearing aid). Possibly, this input might have led to an advantage the first three years after CI. Second, results between cCMV-CI children with and cCMV-CI children without MRI abnormalities and their matched Cx26-CI counterparts tentatively suggest that, over a 5-yr follow-up period, cCMV-CI children with abnormalities on MRI scans catch up for speech perception, but lag behind for speech production. CONCLUSION: cCMV-CI children with normal MRI scans perform equally or even slightly better on speech perception tests compared to their Cx26-CI peers during the first three years, whereas results between cCMV-CI children with and cCMV-CI children without MRI abnormalities and their matched Cx26-CI counterparts tentatively suggest that, over a 5-yr follow-up period, cCMV-CI children with abnormal MRI scans catch up for speech perception, but lag behind for speech production. In future, the inclusion of MRI results may assist in improved counseling of parents with cCMV deafened children seeking CI.