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Biomedical subjects

K Kodera

Publications and source records attributed to K Kodera.

At least 145 records · Page 8Linked to original sources
PubMed1979

Cochlear distribution of frequency-following response initiation. A high-pass masking noise study.

The cochlear initiation of the frequency-following response (FFR) to 500-Hz tone bursts was assessed in 6 normal-hearing subjects by measuring FFR amplitude as a function of the low-frequency cutoff of high-pass masking noise (3 550, 1 800, 900, and 450 Hz). The major fall off of FFR amplitude occurred when the masking noise began to mask the apical portion of the cochlea. This effect was especially apparent at low intensities. The results are interpreted as supporting the view that at low intensities, low-frequency tone bursts evoke the FFR primarily through the apical portion of the cochlea.

Adult↗
PubMed1979

Effects of rise time on simultaneously recorded auditory-evoked potentials from the early, middle and late ranges.

The view that the effects of stimulus rise time are qualitatively different for early brain stem components, middle latency components and late vertex components of the auditory-evoked responses was reexamined. The amplitudes and latencies of the brain stem response (Jewett's wave V), middle latency components Na and Pa, and vertex potentials P1, N1 and P2, evoked by tone burts of various rise times, were analyzed. Increases in rise time were associated with smaller peak amplitudes and longer peak latencies for all of the components measured. These effects were comparable in magnitude for all the components. The results are interpreted in terms of a delayed and less synchronized neural discharge from the cochlea as rise time is extended.

Adult↗
PubMed1979

Cochlear processes affecting wave V latency of the auditory evoked brain stem response. A study of patients with sensory hearing loss.

The effects of inner ear pathologies on wave V latency of the auditory evoked brain stem response (BSR) were studied in 12 selected patients with flat, low-frequency, severe high-frequency, and gradual high-frequency sensory hearing loss. In patients with flat and low-frequency sensory hearing loss (Meniere's disease), the latencies of wave V at intensities 4--10 dB greater than their response thresholds were roughly the same as those in normal-hearing subjects. In patients with severe high-frequency sensory hearing loss (sharp cut-off at about 2 or 3 kHz), the latencies of wave V were always delayed, compared with those in normal-hearing subjects. In patients with gradual high-frequency sensory hearing loss, the latency of wave V was delayed according to the degree of hearing loss (as determined by pure tone audiometry) above 2 kHz. The data are interpreted as showing that the wave V latency is sensitive to a kind of recruiting phenomenon in the transduction process as well as being an index of the pressure wave travel time to the cochlear portion responsible for the elicitation of the BSR.

Adult↗
PubMed1977

Intraoral nerve block for glossopharyngeal neuralgia.

Glossopharyngeal neuralgia was treated by a new method of intraoral block. The procedure consists of block for the tonsillar branch and block of the lingual branch by the injection of 5% Phenol in Glycerin. This can be applied for neuralgia with a trigger zone around the tonsil. The result is quite satisfactory. This is extremely safe and simple, and can be performed repetitively when recurrences occur. Also, this procedure does not preclude later operations as a final step.

Analgesics↗
PubMed1977

The effect of onset, offset and rise-decay times of tone bursts on brain stem response.

Auditory-evoked brain stem responses (BSRs) were recorded from the scalp in 4 cats and 10 human subjects. Auditory stimuli consisted of 1 kHz tone bursts and their duration, intensity and rise--decay time were varied. The BSR evoked by the tone bursts consisted of on- and off-responses. The off-responses showed different intensity--amplitude and different intensity--latency functions from the on-responses. In the feline subjects, an increase in rise time as an input resulted in an increase in the number of recorded sharp waves of the on-responses, indicating that several cycles of tone bursts during the rise time take part in generating on-responses. In both the feline and human subjects, BSRs were evoked by tone bursts with a rise time of as long as 10 msec; an increase in the rise time resulted in an increased latency and broadened waveforms of the on-responses. These demonstrated properties of BSR may provide useful information in determining input parameters, such as rise--decay time, appropriate for audiometric assessment.

Acoustic Stimulation↗