scholarly journals Electrophysiological Investigation of the Auditory System in Friedreich’s Ataxia

Author(s):  
M.J. Taylor ◽  
J.B. McMenamin ◽  
E. Andermann ◽  
G.V. Watters

ABSTRACT:Auditory brainstem responses (ABRs) and cortical auditory evoked responses (AERs) were studied in a series of 16 Friedreich’s ataxia patients who varied in age, degree of clinical involvement and duration of the disorder. The ABRs were markedly abnormal in all but the youngest patient, and the abnormalities reflected the severity and duration of the disease. The latencies of the AERs were significantly longer in the Friedreich’s ataxia patients compared to normal controls, suggesting cortical as well as peripheral involvement of the auditory system. These data are discussed in terms of the neuropathology of the disorder and the similarities with the other sensory systems in Friedreich’s ataxia patients.

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
J. Tillein ◽  
S. Heid ◽  
E. Lang ◽  
R. Hartmann ◽  
A. Kral

To compare the development of the auditory system in hearing and completely acoustically deprived animals, naive congenitally deaf white cats (CDCs) and hearing controls (HCs) were investigated at different developmental stages from birth till adulthood. The CDCs had no hearing experience before the acute experiment. In both groups of animals, responses to cochlear implant stimulation were acutely assessed. Electrically evoked auditory brainstem responses (E-ABRs) were recorded with monopolar stimulation at different current levels. CDCs demonstrated extensive development of E-ABRs, from first signs of responses at postnatal (p.n.) day 3 through appearance of all waves of brainstem response at day 8 p.n. to mature responses around day 90 p.n.. Wave I of E-ABRs could not be distinguished from the artifact in majority of CDCs, whereas in HCs, it was clearly separated from the stimulus artifact. Waves II, III, and IV demonstrated higher thresholds in CDCs, whereas this difference was not found for wave V. Amplitudes of wave III were significantly higher in HCs, whereas wave V amplitudes were significantly higher in CDCs. No differences in latencies were observed between the animal groups. These data demonstrate significant postnatal subcortical development in absence of hearing, and also divergent effects of deafness on early waves II–IV and wave V of the E-ABR.


Author(s):  
M.J. Taylor ◽  
W.Y. Chan-Lui ◽  
W.J. Logan

ABSTRACT:We studied multimodal evoked potentials (EPs) longitudinally in a series of children with Friedreich’s ataxia and ataxia telangiectasia to determine both their diagnostic utility and their correlation with clinical regression.The auditory brainstem responses (ABRs) were abnormal only in the children with Friedreich’s ataxia. The abnormality seen in these patients was a rostral-caudal loss of the ABR waves. The visual EPs (VEPs) were abnormal in many of the patients; those with ataxia telangiectasia had unusually low amplitude or absent VEPs, occasionally with increased latencies, whereas those with Friedreich’s ataxia had normal amplitude VEPs, often at increased latencies. The somatosensory EPs were usually of increased latency or absent in these patients. Unlike the ABR and VEPs, they did not serve to differentiate the groups.Changes in the EPs appeared to reflect clinical deterioration; patients with little change in their EPs over several years were regressing very slowly, whereas others had rapid deterioration in both EPs and clinical status. We suggest that the EPs are diagnostically of value in degenerative ataxias and may be of value in monitoring these patients and their response to therapy.


Author(s):  
R.S. Yufe ◽  
M.L. Hyde ◽  
K. Terbrugge

SUMMARY:We present the first case of central pontine myelinolysis (CPM) confirmed by high resolution computerized tomography (CT) in which auditory brainstem responses (A BR) revealed impaired conduction beyond the mid pons. The combined use of CT and A BR in the diagnosis of central pontine myelinolysis is discussed.


1997 ◽  
Vol 111 (3) ◽  
pp. 218-222 ◽  
Author(s):  
William W. Qiu ◽  
Shengguang S. Yin ◽  
Fred J. Stucker ◽  
Mardjohan Hardjasudarma

AbstractGlomus tumours involving the middle ear and the cerebellopontine angle are reported with emphasis on audiological findings. Magnetic resonance imaging (MRI), angiographic and pathological results are presented. Audiological tests, including impedance audiometry, evoked otoacoustic emissions and auditory brainstem responses, are valuable in evaluation of the effect of glomus tumours on the auditory system as well as their pathological extent.


2015 ◽  
Vol 32 (5) ◽  
pp. 445-459 ◽  
Author(s):  
Kyung Myun Lee ◽  
Erika Skoe ◽  
Nina Kraus ◽  
Richard Ashley

Acoustic periodicity is an important factor for discriminating consonant and dissonant intervals. While previous studies have found that the periodicity of musical intervals is temporally encoded by neural phase locking throughout the auditory system, how the nonlinearities of the auditory pathway influence the encoding of periodicity and how this effect is related to sensory consonance has been underexplored. By measuring human auditory brainstem responses (ABRs) to four diotically presented musical intervals with increasing degrees of dissonance, this study seeks to explicate how the subcortical auditory system transforms the neural representation of acoustic periodicity for consonant versus dissonant intervals. ABRs faithfully reflect neural activity in the brainstem synchronized to the stimulus while also capturing nonlinear aspects of auditory processing. Results show that for the most dissonant interval, which has a less periodic stimulus waveform than the most consonant interval, the aperiodicity of the stimulus is intensified in the subcortical response. The decreased periodicity of dissonant intervals is related to a larger number of nonlinearities (i.e., distortion products) in the response spectrum. Our findings suggest that the auditory system transforms the periodicity of dissonant intervals resulting in consonant and dissonant intervals becoming more distinct in the neural code than if they were to be processed by a linear auditory system.


Author(s):  
S.B. Melancon ◽  
M. Vanasse ◽  
G. Geoffroy ◽  
L. Barabe ◽  
A. Proulx ◽  
...  

SUMMARY:Twenty-two patients with Friedreich’s Ataxia and ten normal controls were followed for one year and assessed as to their clinical performance after two successive six-month periods of lecithin or safflower oil. Results demonstrated no significant difference in performance scores according to group assignation, neither in patients nor in controls. According to stages, two patients in stage I and to a lesser degree, one patient in stage IV showed better scores for muscle strength and some motor accuracy and coordination tests with lecithin. Controls as groups maintained positive scores in all tests. Patients as groups showed negative mean values in nine out of eleven tests. Again as groups, patients receiving safflower oil demonstrated a mean 8% less deterioration than patients receiving lecithin. This study demonstrates that objective clinical tests and the participation of normal controls are a must in a therapeutic trial implicating patients with a progressive disorder such as Friedreich’s Ataxia. The possible role of linoleic acid as the active factor from which clinical improvement proceeded in some specific patients and with early functional stages of the disease, has to be considered and reevaluated in the near future.


2006 ◽  
Vol 17 (09) ◽  
pp. 667-676 ◽  
Author(s):  
Ashley W. Harkrider ◽  
Joanna W. Tampas

Studies of acceptable noise level (ANL) consistently report large intersubject variability in acceptance of background noise while listening to speech. This variability is not related to age, gender, hearing sensitivity, type of background noise, speech perception in noise performance, or efferent activity of the medial olivocochlear pathway. An exploratory study was conducted to determine if differences in aggregate responses from the peripheral and central auditory system can account for intersubject variability in ANL. Click-evoked otoacoustic emissions (CEOAEs), binaural auditory brainstem responses (ABRs), and middle latency responses (MLRs) were measured in females with normal hearing with low (n = 6) versus high (n = 7) ANLs. Results of this preliminary study indicate no differences between the groups for CEOAEs or waves I or III of the ABR. Differences between the two groups emerge for the amplitudes of wave V of the ABR and for the Na-Pa component of the MLR, suggesting that physiological variations arising from more central regions of the auditory system may mediate background noise acceptance.


2019 ◽  
Author(s):  
Andrew Garrett ◽  
Virginia Lannigan ◽  
Nathanael Yates ◽  
Jennifer Rodger ◽  
Wilhelmina Mulders

The fat-tailed Dunnart (Sminthopsis crassicaudata) is a small (10-20g) native marsupial endemic to the south west of Western Australia. Currently little is known about the auditory capabilities of the dunnart, and of marsupials in general. Consequently, this study sought to investigate several electrophysiological and anatomical properties of the dunnart auditory system. Auditory brainstem responses (ABR) were recorded to brief (5ms) tone pips at a range of frequencies (4-47.5 kHz) and intensities to determine auditory brainstem thresholds. The dunnart ABR displayed multiple distinct peaks at all test frequencies, similar to other mammalian species. ABR showed the dunnart is most sensitive to higher frequencies increasing up to 47.5 kHz. Morphological observations (Nissl stain) revealed that the auditory structures thought to contribute to the first peaks of the ABR were all distinguishable in the dunnart. Structures identified include the dorsal and ventral subdivisions of the cochlear nucleus, including a cochlear nerve root nucleus as well as several distinct nuclei in the superior olivary complex, such as the medial nucleus of the trapezoid body, lateral superior olive and medial superior olive. This study is the first to show functional and anatomical aspects of the lower part of the auditory system in the Fat-tailed Dunnart.


Author(s):  
S. B. Melançon ◽  
M. Potier ◽  
L. Dallaire ◽  
G. Fontaine ◽  
B. Grenier ◽  
...  

SUMMARY:Lipoamide dehydrogenase was measued in cultivated skin fibroblasts from twelve patients with Friedreich's ataxia and nine normal controls. No difference in specific activity, subcellular distribution and Vmax or Km was observed between patients and controls.


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