BACKGROUND AND OBJECTIVES: Cochlear implants help patients who suffer from profound hearing loss and for whom hearing aids do not provide enough beneift rehabilitation. Promontory stimulation test (PST), a part of preoperative evaluation for cochlear implants, is not appropriate for prelingually deafened adults and young children because it is measured by the patient's subjective expression to electrical stimulation. Recently, promontory stimulation EABR (PS-EABR) was studied in order to compensate for this disadvantage of PST. The aim of this study is to investigate the feasibility of PS-EABR in the assessment of neural survival of auditory nerve. MATERIALS AND METHOD: PS-EABRs were recorded from subjects with sensorineural hearing loss (group l; pure tone average-between 40 to 70 dB HL) and deafness (group ll; pure tone average < 90 dB HL). Electrical stimulation was performed with the tip of a transtympanic electrode placed on the promontory near the round window niche. We compared PS-EABR waveforms, thresholds, wave V latencies and amplitudes. RESULTS: Stable PS-EABR waveforms were obtained in both groups. The typical PS-EABR waveform consisted of a series of two to three peaks. The largest peak among them was the wave V which is was not identifiable due to a stimulus artifact. The mean thresholds of PS-EABR were 389.3 +/- 220.3 microampere in the group l and 921.4 +/- 610.4 microampere in the group ll. The maximal acceptable level (MAL) was 746.4 +/- 371.3 microampere in the group l and 2150 +/- 980.2 microampere in the group ll. The mean wave V latencies at threshold level were 4.63 +/- 0.07 msec in the group l and 4.58 +/- 0.35 msec in the group ll and were not significantly changed as the stimulus intensity increased. There was no statistical significant difference between these two groups. The mean wave V amplitudes at threshold level were 0.65 +/- 0.58 microvoltin the group l and 0.89 +/- 1.04 microvoltin the group ll. The amplitude of the wave V in the group l and the group ll increased as the stimulus intensity increased. There was no significant difference between these two groups. CONCLUSION: The results of this study suggest that PS-EABR will be useful in preoperative evaluation of neural survival in young children and prelinguistically deafened adults with limited communication abilities.
Adult ; Artifacts ; Child ; Cochlear Implants ; Cochlear Nerve ; Communication ; Deafness ; Electric Stimulation ; Electrodes ; Hearing Aids ; Hearing Loss ; Hearing Loss, Sensorineural* ; Humans ; Rehabilitation

BACKGROUND AND OBJECTIVES: This study was designed to identify whether canal type hearing aids can be used by the patients who have undergone epitympanoplasty with mastoid obliteration for postoperative rehabilitation of hearing impaired and also to investigate the advantages of the complete in the canal (CIC) hearing aid for the postoperative rehabilitation of hearing impaired. SUBJECTS AND METHOD: Fourty-three ears belonging to 40 adults, who were treated by epitympanoplasty with mastoid obliteration for cholesteatoma from April 1995 to May 1999 were involved in this study. The impressions were taken and measured postoperatively by Vernier calipers anteroposteriorly (AP) and superoinferiorly (SI). It is well known that the size of the external auditory canal (EAC) should be over 7 mm in diameter and over 2 cm in length to be able to wear the CIC type hearing aid. The shape of the EAC was also taken into consideration. RESULTS: Thirty-five out of 43 ears were large enough to wear CIC hearing aids and all 43 for the canal (ITC) hearing aids. No ears were excluded from being able to wear a CIC or ITC hearing aid with respect to the shape of the EAC. CONCLUSION: Canal type hearing aides can be used after epitympanoplasty with mastoid obliteration which is used as a treatment of cholesteatoma.
Adult ; Cholesteatoma ; Correction of Hearing Impairment* ; Ear ; Ear Canal ; Hearing Aids ; Humans ; Mastoid* ; Rehabilitation*

Background: and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. Methods: Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. Results: Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). Conclusions The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Background: and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. Methods: Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. Results: Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). Conclusions The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.