PubMed Health⌕ Search

Biomedical subjects

L G Spivak

Publications and source records attributed to L G Spivak.

13 recordsLinked to original sources
PubMed1994

The relationship between electrical acoustic reflex thresholds and behavioral comfort levels in children and adult cochlear implant patients.

The accuracy with which behavioral comfort levels could be predicted by the electrically elicited acoustic reflex threshold (EART) was examined in 35 Nucleus Cochlear Implant patients (16 adults and 19 children). EARTs were obtained by stimulating bipolar pairs of electrodes through the Nucleus Diagnostic Programming System and monitoring the change in middle ear admittance in the ear contralateral to the implanted ear. EARTs were successfully elicited in 24 patients. EARTs differed from behavioral comfort levels by a mean of 19.4 stimulus level units for adults and 9.6 stimulus level units for children. While EARTs were found to be acceptably close to behavioral comfort levels in four adults and eight children, EARTs significantly overestimated or underestimated comfort levels in the rest. The results of this study suggested that while the EART does not accurately predict comfort levels in all cases, it may provide valuable information regarding levels which should not be exceeded when programming the cochlear implant. Cautious use of information available from the EART may prove useful for programming the cochlear implant in children or adults who are unable to make reliable psychophysical judgments.

Acoustic Stimulation↗
PubMed1994

Programming the cochlear implant based on electrical acoustic reflex thresholds: patient performance.

The electrical acoustic reflex threshold (EART) has been shown to be a reliable estimate of behavioral comfort levels in both child and adult cochlear implant patients. The purpose of this study was to investigate the potential for using EARTs for programming the Nucleus cochlear implant. EARTs and behavioral comfort levels were obtained from 7 adult implant patients. Two programs or "maps" were made for each patient, one based on behavioral comfort levels and one based on EARTs. Performance on open set tests of speech recognition was measured with each map. Mean data suggest that speech perception is similar with both maps. Analysis of individual data revealed that, whereas 2 subjects performed better with the C-level maps, the remaining 5 subjects tended to perform either better with the EART map or equally well with both maps. These results suggest that EARTs may be an adequate substitute for comfort levels when programming the implant for patients who are unable to make reliable psychophysical judgments.

Adult↗
PubMed1991

Effect of digital filtering of ABR on scorer variability.

The utility of digital filtering for the purpose of improving waveform morphology and improving peak detection was investigated. Unfiltered (i.e., only standard analog filtering) and digitally filtered (i.e., analog plus post hoc digital filtering) ABRs from both young and elderly subjects were independently scored by eight experienced clinicians. Measures of intrascorer and interscorer variability were obtained for the absolute latencies of waves I, III, and V. Results suggest that digital filtering tends to increase the reliability of latency measurements when ABRs are characterized by poor morphology.

Acoustics↗
PubMed1990

Performance of cochlear implant patients as a function of time.

The speech perception abilities of 15 patients were measured preoperatively using hearing aids and postoperatively using the Nucleus 22-channel cochlear implant over a period of 1, 2, or 3 years. Analysis of mean data revealed that, although the greatest amount of improvement in speech perception scores occurred between the preoperative and 3-month poststimulation evaluation, there was also significant improvement in perception of segmental features and open-set speech recognition over the 3-year time period. When individual patient data were examined, however, it was clear that these improvements were due, in large part, to the performance of a subset of patients who had measurable open-set speech recognition abilities at the time of their 3-month, poststimulation evaluation. Subjects who used the processing scheme that included coding of F1 showed significantly more improvement over time than subjects who used the original F0F2 processing scheme exclusively. It was concluded that open-set speech recognition ability at 3 months is an important prognostic indicator of continued improvement in speech perception abilities over time.

Adult↗
PubMed1990

Spectral differences in the ABRs of old and young subjects.

The purpose of the present study was to analyze and compare the amplitude spectra of ABRs recorded from 40 elderly and 40 young subjects in order to determine if there are any age related differences. A spectral analysis was performed on each subject's ABR. It was found that the ABRs recorded from older subjects have a significantly greater amount of low frequency spectral energy than ABRs recorded from young subjects. This difference was attributed to the greater amount of low frequency background noise found in the ABRs of older subjects. Modification of standard recording procedures should be considered when ABRs are recorded from older subjects.

Adolescent↗
PubMed1990

Effect of stimulus parameters on auditory brainstem response spectral analysis.

A recent increase of interest in spectral analysis has been prompted by the suggestion that spectral components of the ABR may contribute to differential diagnosis. Knowledge of the effects of stimulus parameters on the spectral content of the ABR is essential. The present study examined the effect of intensity, rate, and polarity on the spectral content of ABRs of 15 normal-hearing subjects. The effects of intensity were significant at all spectral frequencies examined while the effects of rate and polarity were frequency specific. These results indicate that the effects of stimulus parameters must be considered in examining the ABR spectral analysis.

Acoustic Stimulation↗
PubMed1988

Response asymmetry and binaural interaction in the auditory brain stem evoked response.

Asymmetry in the auditory brain stem evoked response (ABR) and its effect on measurements of binaural interaction were studied. Monaural and binaural ABRs were recorded from 24 normal hearing subjects at two sensation levels: 70 and 50 dB. Monaural responses were judged to be asymmetrical when the right response minus the left response resulted in a difference trace which was significantly greater than the level of the background noise in the ABR. It was found that sensation level significantly affected the frequency of monaural response asymmetry and that the amplitude of the derived binaural interaction component (BIC) was positively correlated with the degree of asymmetry present. Offsetting the asymmetry by introducing an interaural intensity difference resulted in a significant reduction in the amplitude of the BIC. It was concluded that the BIC is affected by factors other than those which can be attributed solely to binaural interaction.

Acoustic Stimulation↗
PubMedDate not supplied

Spectral composition of infant auditory brainstem responses: implications for filtering.

Auditory brainstem responses (ABRs) were recorded from 20 normal neonates and 10 normal-hearing adults. The spectral compositions of ABRs from both groups were compared. Results indicated that significant amounts of low-frequency information are concentrated below 150 Hz in both the neonate and the adult ABRs although the neonate ABR has a slightly greater percentage of low-frequency information than that of the adults. This has implications for filtering during ABR recording. A low high-pass setting which preserves more of the low-frequency information will allow enhanced detectability of wave V in neonate ABRs recorded at low stimulus intensities. Furthermore, our experience indicates that the use of a 30- to 3,000-Hz bandpass is feasible in the neonatal intensive care unit as well as in the regular newborn nursery. Therefore the use of a 30- to 3,000-Hz bandpass is recommended for neonate ABR recordings.

Acoustic Stimulation↗
PubMedDate not supplied

[Five-year experience in treating patients with prostatic hyperplasia patients with permixone (Serenoa repens "Pierre Fabre Medicament)].

Specialists of the urologic clinic of the I.M. Sechenov Moscow Medical Academy studied effectiveness of lipidosterol extract Serenoa repens (permixon) in 26 patients with prostatic hyperplasia (total prostate-specific antigen was under 4 ng/ml). The trial has been performed from November 1995 up to now. The drug was taken before meal with a small quantity of water in a total daily dose 320 mg twice a day. Initial IPSS values ranged from 8 to 18 scores (mean 11.65 +/- 0.59). Life quality index was 1 to 4 scores (mean 2.46 +/- 0.15). Initial size of the prostate varied from 26 to 63 cm3 (mean 36.23 +/- 1.57 cm3). Maximal urinary flow rate (Qmax) made up 8.7 to 14.6 ml/s (mean 11.83 +/- 0.31 ml/s). Residual urine was initially 0-60 ml (mean 10.58 +/- 2.91 ml). Permixon significantly reduced the disease symptoms and improved quality of life. 5 years of treatment decreased mean IPSS by 8.8 +/- 0.18 (75.5%). QOL--by 1.31 +/- 0.08 (53.3%), size of the prostate--by 10.81 +/- 0.55 cm3 (29.8%). Neither the symptoms nor quality of life became worse for these five years. The size of the prostate reduced in 16, unchanged in 9 and increased only in 1 patient. Qmax was initially under 15 ml/s and rose after the treatment by 4.13 +/- 0.51 ml/s (35%), on the average. Qmax rose above 15 ml/s in 16 patients. Residual urine increased during the treatment in one patient only. Permixon intolerance was not observed. Thus, continuous 5-year therapy with lipidosterol extract Serenoa repens (permixon) proved highly effective and safe in 26 patients with initial or moderate symptoms of prostatic hyperplasia.

Androgen Antagonists↗
PubMedDate not supplied

[Biodegradable prostatic stents in treating patients with prostatic enlargement].

A total of 39 patients with prostatic hyperplasia (PH) admitted to the urological clinic of I. M. Sechenov Moscow Medical Academy from 1999 have been inserted a biodegradable catheter stent (BCS). Such stents degrade spontaneously to microfragments and come away with urine 4-12 months after catheterization. BCS were used in PH patients with marked urination disorders due to urethral compression by hyperplastic prostate in whom adenomectomy was contraindicated. BCS was used for elimination of a suprapubic fistula in the urinary bladder of 19 PH patients with contraindications to adenomectomy. 5-7 days before catheterization the urinary bladder was drained 2 times a day to reduce pyoinflammatory process. The cystostomic fistula closed within 24 h in all the patients. Adequate urination recovered. Urethral inflammation persisted for 4-6 weeks. It was treated with antibiotics with effectiveness 89.5% (in 17 of 19 patients). Pyoinflammation persisted in two patients who developed uroliths destructed later at endoscopic pneumatic cystolithotripsy. Control examination 6 months after the stent insertion found that the stent had destructed with evacuation of the fragments. In two patients two large fragments were locked in the urethra provoking acute ischuria. The fragments were removed by the forceps and urination became normal. None of the patients needed recystostomy. 32 stented patients 6 and 12 months after stenting had adequate urination (mean Qmax--12.3 and 10.8 ml/s, respectively). Mean residual urine--32 and 37 ml. BCS improves treatment outcomes and quality of life of PH patients with contraindications to adenomectomy.

Biocompatible Materials↗
PubMedDate not supplied

[Efficiency and safety of prostamol-Uno in patients with chronic abacterial prostatitis].

In this open label prospective study in patients with category III prostatitis we assessed efficacy and safety of Sabal serrulata plant extract (prostamol Uno 320 mg) (group I, n=30) as compared to watchful waiting (group II, n=24). Efficacy was evaluated by means of NIH-CPSI, IPSS-QoL questionnaires, patients' general subjective assessment of treatment outcome, uroflowmetry and transrectal Doppler mapping (colour doppler and spectral doppler) of the prostate. Patients receiving prostamol Uno in comparison with watchful waiting group had significant improvement of mean NIH-CPSI (from 17.8 to 11.4 vs 17.1 to 16.5) and IPSS (from 13.0 to 6.3 vs 13.2 to 11.6) scores, Qmax values (from 12.9 ml/s to 17.8 ml/s vs 13.3 ml/s to 14.4 ml/s) and Doppler parameters of vascular resistance in the prostate. According to the patients' subjective assessment, moderate and significant improvement was reported by 76.7% patients in prostamol Uno group vs 23.3% in the watchful waiting group. There were no severe side effects. In prostamol Uno group one patient (3.3%) had moderate dyspepsia that resolved without termination of the drug administration. Prostamol Uno showed good efficacy and safety profile in patients with category III prostatitis.

Adolescent↗