Multiple sclerosis presented acute hearing loss and vertigo.

Prolonged brainstem transmission time in autism

This paper studies the effect of otologic disease on the brain stem auditory evoked response (BAER). Both conductive and neurosensory hearing losses are analyzed by plotting wave V latencies and amplitudes as a function of sound intensity. It was found that the BAER is elicited primarily by frequencies greater than 2000 Hz. Conductive hearing losses produce a latency intensity function which approaches the norm with high decibel stimulation. Neurosensory losses produce a variety of latency intensity functions. In determining the degree of hearing loss, wave threshold is found to be the best index. Wave latency at high decibels is found to have little correspondence to degree of neurosensory loss; wave amplitude is highly variable among subjects but still a useful indicator for detecting pathology. Between-ear comparisons of wave latencies elicited by high decibel sound stimulation suggest that unilateral nonrecruiting or partially recruiting hearing losses will result in a latency difference. This method can be used to detect unilateral acoustic neuromas, and the false positives found by this technique are probably caused by other unilateral nonrecruiting hearing losses. In evaluating neurological disease, and especially when testing for a second occult lesion in multiple sclerosis (MS) an audiogram should be obtained because the criterion of a normal wave latency with decreased amplitude for the diagnosis of MS can be mimicked by peripheral hearing loss.

Purpose The brainstem dysfunction in multiple sclerosis (MS) often causes significant functional impairment leading to disability. This study aims to explore modified brainstem auditory evoked potential (BAEP) scores based on the pattern of BAEP abnormalities and relate with brainstem symptoms, brainstem functional system scores (BFSS), brainstem lesions, and disability. Method Forty-five participants with relapsing-remitting MS and 45 age- and gender-matched healthy controls underwent case history assessment, otoscopic examination, pure-tone audiometry, and BAEP testing. Also, neurological examination (Expanded Disability Status Scale, FSS scales) and magnetic resonance imaging were carried out on MS participants. Patterns of BAEP abnormalities were categorized and converted to BAEP scores. Results Out of 45 participants' brainstem symptoms, BFSS > 1, brainstem lesions (magnetic resonance imaging), and BAEP abnormalities were observed in 75.6%, 42.2%, 62.2%, and 55.56% of participants, respectively. Waves V and III abnormalities were more common among MS participants and showed a significant difference from the control group in the Mann-Whitney U test. Chi-square test did not show a significant association of BAEP abnormalities with brainstem symptoms and lesions but showed significant association with BFSS. The mean and standard deviation of BAEP scores in MS participants were 1.73 + 2.37. All healthy controls showed BAEP scores of 0. BAEP scores in MS participants showed significant correlation with BFSS scores and predict Expanded Disability Status Scale scores. Conclusion BAEP scores based on the pattern of BAEP abnormality can be a valid and useful measure in evaluating brainstem functions and predicting disability in MS.

One hundred patients with multiple sclerosis (MS) were analysed retrospectively with respect to investigations of brain-stem auditory evoked potentials (BAEP), pattern reversal visual evoked potentials (VEP), somatosensory evoked potentials (SEP), and cerebrospinal fluid immunoglobulins (CSF-IG). BAEP were abnormal in 42% of those with normal VEP and SEP examinations, and in 38% of patients with normal CSF-IG. The chance of obtaining at least one abnormal EP was lower in patients with normal CSF-IG than in patients with abnormal CSF. When a "dispersion ratio" was included in the criteria for BAEP abnormality, the sensitivity increased compared with conventional BAEP criteria. We recommend that BAEP should still be included in the EP test battery for patients with suspected MS.

Brainstem auditory evoked responses (BAERs) were recorded from 202 patients with definite, probable, or possible multiple sclerosis (MS). Definitions of abnormality were based only on interwave separations and the wave I/wave V amplitude ratio. Thirty-two percent of the patients had abnormal BAERs, and the presence of clinically unsuspected lesions was revealed by BAER abnormalities in 7.4%. Thirty-five percent of the patients who had nystagmus and 53% of those who had internuclear ophthalmoplegia at the time of testing had BAER abnormalities. Forty-five percent of the abnormalities were elicited with stimulation of one ear only, stressing the importance of monaural stimulation. Click rates faster than 10 per second did not reveal abnormalities undetected at slower rates. BAERs were normal by these criteria in patients with labyrinthine diseases and amyotrophic lateral sclerosis. Thus, the BAER in MS can (1) confirm the presence of central lesions in patients with suspected brainstem involvement, (2) document the presence of clinically unsuspected lesions, and (3) be followed over time to provide possible assistance in evaluating the effectiveness of therapeutic measures. The BAER is a useful tool in the diagnosis and management of MS.

BackgroundThe purpose of this study was to compare the effectiveness of methods for screening for retrocochlear pathologies based on auditory evoked brainstem responses (ABRs). The study compared the sensitivity, specificity, and effectiveness of these 3 techniques.Material/MethodsThe methods were: (i) standard ABR utilizing click-evoked responses, (ii) stacked ABR based on derived-band responses, and (iii) ABRs evoked by tone-pips (ABR TP). The methods were tested on patients with retrocochlear pathologies confirmed by MRI-Gd, normal-hearing subjects, and patients with cochlear hearing loss. The system and software used in the tests was NavPro AEP v.6.2.0 (BioLogic – Natus). Prior to testing, all subjects were given comprehensive audiologic and otologic examinations, including MR imaging. Sensitivity and specificity functions and predictive values of methods were determined.ResultsThe stacked ABR method as realized in the NavPro system exhibited high sensitivity but specificity was very low, due to the high variability of stacked ABR amplitudes. The standard ABR method had good specificity, but low sensitivity in cases of small tumors (below 1 cm in diameter). Best sensitivity and specificity was obtained with the ABR TP method.ConclusionsThe stacked ABR method allows small acoustic tumors to be detected, but produces high percentage of false positive results. The ABR TP method offers good sensitivity and specificity, and relatively high predictive value. The best option would be to use a two-stage screening, consisting of a standard ABR in the first stage and an ABR TP test in the second.

Objective To study the pathogenesis and surgical treatment of atypical hemifacial spasm.Methods The clinical data of 36 patients who underwent microvascular decompressions (MVD) for atypical hemifacial spasm(HFS)from July 2005 to July 2010 were retrospectively analyzed.Results The HFS disappeared immediately after MVD in 32 patients.The postoperative spasm was weaker in 4 patients and the residual spasm was disappeared within 5 months.There was no reoccurrence of spasm during follow -up period.The postoperative complications included:transient moderate facial paralysis accompanied with hearing dysfunction in 3 cases,and transient hearing dysfunction accompanied with tinnitus in 3.Conclusions Atypical hemifacial spasm is caused by vessels on the posterior rostral side of facial nerve.The effectiveness could be predicted after MVD.But the rates of facial paralysis and/or hearing loss are relatively higher.The rates of complications could be reduced significantly by correct identification of offending vessels,fewer disturbance to cranial nerves,avoiding the injury to the penetrating vessels,and intraoperative brain stem auditory evoked potential monitoring during. Key words: Microsurgical decompression; Atypical hemifacial spasm; Facial nerve ; Brain stem auditory evoked potential

Power spectral analysis normal and pathological brainstem auditory evoked potentials

A comparison of brainstem auditory evoked responses evoked by rarefaction and condensation stimulation in control subjects and in patients with Wernicke-Korsakoff syndrome and multiple sclerosis

A developing method for testing auditory function and detecting neurological disorders is the brain stem auditory evoked response (BAER) to sound stimuli. Elicitation of the BAER is noninvasive and produces an objective measurement of a subject's auditory function. Basic principles of this technique and normative data are presented in this paper. It was found that the BAER can detect asymptomatic high-frequency hearing losses. The sensitivity of this technique makes it an ideal method for evaluating functional hearing losses. Two illustrations of functional hearing losses are presented. Wave V's threshold, latency and amplitude, along with comparisons between the auditory (subjective) and BAER threshold, are useful parameters when testing for nonorganic hearing disorders. However, this sensitivity to minor hearing losses makes it imperative that all control subjects be established as normal by an audiogram. A mere negative history for hearing disorders is felt by the authors to be an inadequate screening of control subjects.

The critical warning sign of real-time brainstem auditory evoked potentials during microvascular decompression for hemifacial spasm

With the requirement of universal newborn hearing screening from the year 2010, throughout the Brazilian territory, more children are undergoing audiologic diagnosis in their first months. The Brainstem Auditory Evoked Potential and the Steady State Evoked Potential are widely used for closing the audiologic diagnosis at this age, since they assist in the characterization of hearing loss as to the degree, type and configuration. The stimuli used in these procedures pose limitations inherent to the acoustic characteristics of each subject and should be taken into account by the professional analyzing the results. Therefore, this study aimed to compare the applicability of the Narrow Band CE-Chirp stimulus to predict the psychoacoustic thresholds in severe and profound sensorineural hearing loss. This was a cross-sectional prospective study in which 28 children, being 15 females and 13 males, aged 6 to 37 months, presented with sensorineural hearing loss and with thresholds above 61 dBNA, were assessed. The used procedures were Brainstem Auditory Evoked Potential with tone burst stimuli and Narrow Band CE-Chirp, Steady-state auditory evoked potential and audiometry with visual reinforcement or conditioned ludic audiometry. The results showed that the electrophysiological thresholds in the Brainstem Auditory Evoked Potential were closer to the psychoacoustic thresholds obtained in the visually reinforced audiometry or conditioned ludic audiometry when using the Narrow Band CE-Chirp stimulus in lieu of the tone burst. In the absence of response in the Brainstem Auditory Evoked Potential with both stimuli, it was observed that the Steady State Auditory Evoked Potential performed at high intensities presented good correlation with the psychoacoustic thresholds, nevertheless, high intensity should be used with caution in the frequencies 2000 and 4000 Hz, for unreal electrophysiological thresholds not to be obtained. It was concluded that, clinically, the use of Brainstem Auditory Evoked Potential with the Narrow Band CE-Chirp stimulus showed electrophysiological thresholds closer to psychoacoustic ones of the audiometry with visual reinforcement/conditioned ludic audiometry than when using the tone burst. Nevertheless, further studies should be performed to verify the benefits of this stimulus in children and with some hearing impairment. For using stimuli in higher intensities, the Steady-state auditory evoked potential characterized the residual hearing, accurately, at frequencies of 500 and 1000 Hz.

Brainstem auditory evoked potentials in microvascular decompression for hemifacial spasm: A prospective study

Age-related hearing loss was studied in unanesthetized female BDF1 mice using brainstem auditory evoked potential (BAEP) latency-intensity (L-I) profiles and BAEP thresholds. The mice were divided into 5 age-related groups: 3-4 months, 5.5-7 months, 9-10 months, 12 months and 18 months. Relative to the youngest group, BAEP threshold data indicated shifts in auditory sensitivity ranging from +6 dB for the 5.5- to 7-month-old group to +71 dB for the 18-month-old group. The BAEP L-I profiles of older mice were consistent with recruitment-type sensorineural (cochlear) hearing losses. No evidence of retrocochlear involvement was observed.

Diagnostic value of multimodal evoked potentials in patients with multiple sclerosis