Bogusława Orecka

Influence of aging on medial olivocochlear system function

Background There is still controversy regarding the influence of aging on medial olivocochlear (MOC) system function. The main objective of this study is to measure age-related changes of MOC system function in people with normal hearing thresholds. Method Bilateral assessment of the MOC effect for click-evoked otoacoustic emissions (CEOAEs; at 70±3 dB peak sound pressure level [pSPL], click at 50/second, 260 repeats, 2.5–20 millisecond window) and for distortion product otoacoustic emissions (DPOAEs; with [frequencies] f2/f1=1.22, [levels of primary tones] L1=65 dB SPL and L2=55 dB SPL; DP-grams for 2f1–f2 were collected for the f1 frequencies varying from 977 Hz to 5,164 kHz, with the resolution of four points per octave) was performed in a group of 146 (n=292 ears) healthy, right-handed subjects aged from 10–60 years with a bilateral hearing threshold from 0.25–4.0 kHz, not exceeding 20 dB hearing level; normal tympanograms; and a threshold of the contralateral stapedial reflex for broadband noise (BBN) of 75 dB SPL or higher. The MOC inhibition was assessed on the basis of changes in OAE level during BBN contralateral stimulation at 50 dB sensation level (mean, 65±3 dB SPL). Results Comparative analysis of the MOC effect for CEOAE and DPOAE showed the weakest effect in the oldest age group (41–60 years) at almost all tested frequencies. Moreover, a weak, albeit significant, positive correlation between the level of OAE and the size of the MOC effect was documented. Conclusion On the basis of our study, we have found a decrease in the strength of the MOC system with increasing age in normally hearing subjects, as reflected by a decrease of the OAE suppression effects in older individuals and an increase of the number of CEOAE and DPOAE enhancements during contralateral acoustic stimulation in the elderly, especially in the high-frequency range.

Ocena wybranych biomateriałów do rekonstrukcji perforacji przegrody nosa

INTRODUCTION The septal nasal perforation is an important problem for the laryngologists and plastic surgeons. The reasons of septal nasal perforations are injuries, neoplasm, self-mutilation, chronic rhinitis, allergy, Wegener granuloma, sarcoidosis, tuberculosis, toxic metals (arsenic, chrome), some drugs (steroids), narcotizing agents (cocaine) and complications after endoscopic and septal nasal operations. The surgical treatment, especially in the cases of large septal perforation, is often difficult because of the atrophy of nasal mucosa and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. The following autogenous tissues were used in the reconstruction of septal perforation: alloderm, temporal fascia, septal and auricle cartilage, cranial periosteum, perichondrium, ethmoidal and hip bone. The defect of such materials is progressive resorption. For many years the suitable synthetic material for septal nasal reconstruction has been searched for. Among the biomaterials the following have been used without success: Dacron, porous polyethylene, dolomite, bioglass. The rejection of synthetic material was the reason of failure. The aim of our study was to evaluate two different biomaterials with proper mechanical and biological features for nasal cartilage replacement. MATERIAL AND METHODS We studied two types of biomaterials: biostable terpolymer PTFE/PVDF/PP and resorbable copolymer of glycolide and L-lactide (PGLA). The pilot studies were performed on two experimental animals (rabbits). The animals were operated in the general anesthesia. The biomaterials were implanted in the rabbit auricular cartilage because of its similarity to the septum and easy surgical access. Subperichondrically 1 x 1 cm fragment of the cartilage was removed. This fragment was then replaced with the biomaterial. The rabbits were painlessly sacrificed after 4 months of observation. RESULTS A very good integration of PGLA implant with auricular cartilage was observed. In the histological examination the lack of excessive inflammatory reaction as well as no cartilage necrosis were observed. CONCLUSIONS 4 months after implantation of PGLA in the rabbit auricular cartilage very good macroscopic and histological results were achieved.Summary Introduction The septal nasal perforation is an important problem for the laryngologists and plastic surgeons. The reasons of septal nasal perforations are injuries, neoplasm, self-mutilation, chronic rhinitis, allergy, Wegener granuloma, sarcoidosis, tuberculosis, toxic metals (arsenic, chrome), some drugs (steroids), narcotizing agents (cocaine) and complications after endoscopic and septal nasal operations. The surgical treatment, especially in the cases of large septal perforation, is often difficult because of the atrophy of nasal mucosa and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. The following autogenous tissues were used in the reconstruction of septal perforation: alloderm, temporal fascia, septal and auricle cartilage, cranial periosteum, perichondrium, ethmoidal and hip bone. The defect of such materials is progressive resorption. For many years the suitable synthetic material for septal nasal reconstruction has been searched for. Among the biomaterials the following have been used without success: Dacron, porous polyethylene, dolomite, bioglass. The rejection of synthetic material was the reason of failure. The aim of our study was to evaluate two different biomaterials with proper mechanical and biological features for nasal cartilage replacement. Material and methods We studied two types of biomaterials: biostable terpolymer PTFE/PVDF/PP and resorbable copolymer of glycolide and L-lactide (PGLA). The pilot studies were performed on two experimental animals (rabbits). The animals were operated in the general anesthesia. The biomaterials were implanted in the rabbit auricular cartilage because of its similarity to the septum and easy surgical access. Subperichondrically 1 x 1 cm fragment of the cartilage was removed. This fragment was then replaced with the biomaterial. The rabbits were painlessly sacrificed after 4 months of observation. Results A very good integration of PGLA implant with auricular cartilage was observed. In the histological examination the lack of excessive inflammatory reaction as well as no cartilage necrosis were observed. Conclusions 4 months after implantation of PGLA in the rabbit auricular cartilage very good macroscopic and histological results were achieved.

Przydatność arytenoidektomii laserowej i laterofiksacji w leczeniu obustronnego porażenia fałdów głosowych

INTRODUCTION Bilateral vocal cord paralysis is caused by the damage of both recurrent laryngeal nerves. Such a pathology is not commonplace in the ordinary medical practice. It most often occurs as a complication after the thyroid gland surgery or thyroid re-surgery. In the case of bilateral vocal cord paralysis the treatment of the patient includes performing immediate tracheotomy or one of the surgeries aiming at widening the glottis because of dyspnea caused by the upper respiratory tract obstruction on the glottis level. AIM The comparison of efficacy and usefulness of two surgical techniques performed to widen the glottis – laser arytenoidectomy with posterior cordectomy and laterofixation. MATERIAL AND METHODS The research was carried out on the group of 57 patients suffering from bilateral vocal cord paralysis who, in the period of 1997–2009, underwent treatment in ENT Department in Zabrze Medical University of Silesia in Katowice. The first group included 36 patients who underwent laser arytenoidectomy with posterior chordectomy. The second group included 21 patients who underwent laterofixation. All of the patients treated with the laser arytenoidectomy with posterior cordectomy and laterofixation were subjected to respiratory system ventilation examinations before the procedure of widening the glottis and after the healing, at least 4 months after the surgery. Making self-evaluation, each of the patients answered a question concerning the improvement of their breathing comfort after the surgery. The patients from both groups underwent the vocal apparatus examination which included: subjective perceptive voice analysis according to GRBAS scale, videolaryngostroboscopy, evaluation of the maximum phonation time, self-evaluation survey of the post-surgical voice quality. RESULTS Among 57 patients suffering from bilateral vocal cord paralysis and operated by arytenoidectomy with posterior cordectomy (group I) and laterofixation (group II), a subjective improvement of the comfort of living was achieved which resulted in the possibility of making more physical activities. From the first group, 35 out of 36 patients were decannulated. In the second group, both patients who had previously undergone tracheotomy were successfully decannulated. There were no statistically significant differences in the increase of selected ventilation markers between the patients who underwent laser arytenoidectomy and those who underwent laterofixation. There were no substantial discrepancies in the perceptive voice analysis in GRBAS scale between the patients after laser arytenoidectomy and those treated with the technique of laterofixation. When asked about their post-surgical voice quality, the patients of the first and the second group rated their voice as worse than before the surgery. CONCLUSION Both surgical techniques, laser arytenoidectomy with posterior cordectomy and laterofixation, are efficient and useful in widening the glottis in the case of bilateral vocal cord paralysis. The improvement of the ventilation markers allows the growth in the comfort of living, restoration of the physiological respiratory tract and decannulation of the patients who had undergone tracheotomy. The deterioration of the voice quality is characteristic of both surgical techniques.Summary Introduction Bilateral vocal cord paralysis is caused by the damage of both recurrent laryngeal nerves. Such a pathology is not commonplace in the ordinary medical practice. It most often occurs as a complication after the thyroid gland surgery or thyroid re-surgery. In the case of bilateral vocal cord paralysis the treatment of the patient includes performing immediate tracheotomy or one of the surgeries aiming at widening the glottis because of dyspnea caused by the upper respiratory tract obstruction on the glottis level. Aim The comparison of efficacy and usefulness of t wo surgical techniques performed to widen the glottis – laser arytenoidectomy with posterior cordectomy and laterofixation. Material and methods The research was carried out on the group of 57 patients suffering from bilateral vocal cord paralysis who, in the period of 1997–2009, underwent treatment in ENT Department in Zabrze Medical University of Silesia in Katowice. The first group included 36 patients who underwent laser arytenoidectomy with posterior chordectomy. The second group included 21 patients who underwent laterofixation. All of the patients treated with the laser arytenoidectomy with posterior cordectomy and laterofixation were subjected to respiratory system ventilation examinations before the procedure of widening the glottis and after the healing, at least 4 months after the surgery. Making self-evaluation, each of the patients answered a question concerning the improvement of their breathing comfort after the surgery. The patients from both groups underwent the vocal apparatus examination which included: subjective perceptive voice analysis according to GRBAS scale, videolaryngostroboscopy, evaluation of the maximum phonation time, self-evaluation survey of the post-surgical voice quality. Results Among 57 patients suffering from bilateral vocal cord paralysis and operated by arytenoidectomy with posterior cordectomy (group I) and laterofixation (group II), a subjective improvement of the comfort of living was achieved which resulted in the possibility of making more physical activities. From the first group, 35 out of 36 patients were decannulated. In the second group, both patients who had previously undergone tracheotomy were successfully decannulated. There were no statistically significant differences in the increase of selected ventilation markers between the patients who underwent laser arytenoidectomy and those who underwent laterofixation. There were no substantial discrepancies in the perceptive voice analysis in GRBAS scale between the patients after laser arytenoidectomy and those treated with the technique of laterofixation. When asked about their post-surgical voice quality, the patients of the first and the second group rated their voice as worse than before the surgery. Conclusion Both surgical techniques, laser arytenoidectomy with posterior cordectomy and laterofixation, are efficient and useful in widening the glottis in the case of bilateral vocal cord paralysis. The improvement of the ventilation markers allows the growth in the comfort of living, restoration of the physiological respiratory tract and decannulation of the patients who had undergone tracheotomy. The deterioration of the voice quality is characteristic of both surgical techniques.

Wyniki czynnościowe po leczeniu zmian zwężających światło krtani

UNLABELLED Six subjects before and after surgery because of the laryngeal stenosis were presented. In 3 cases laryngeal web was recognised which arises after endoscopical removal of infant papilloma. The scar after laser chordectomy due to carcinoma of the larynx occurred in remaining 3 patients. All presented patients simultaneously were undergoing removal of the lesion endoscopically and insertion of silastic separator. AIM Respiratory and phonatory function assessment in patients who were operated because of the laryngeal stenosis was the aim of this study. METHODS Treatment effectiveness was estimate on the basis of pre- and postoperative spirometry with flow--volume loop and postoperative phoniatric examination. Ventilatory function was analysis on the basis of the following parameters: PIF, FEV1, FIV1, PEF, FVC. Phoniatric examination was performed after 2 months of outpatient observation and rehabilitation. It consisted of subjective voice assessment using GRBAS scale, videolaryngostroboscopy and assessment of the phonation time. RESULTS Some of the analysed parameters especially in patients with posterior stenosis were significantly better after surgery. Phoniatric rehabilitation after surgery caused improvement of voice quality and phonatory function of the larynx. CONCLUSION Thanks to insertion of silastic separator good phoniatric function and ventilation efficiency are possible.Summary Six subjects before and after surgery because of the laryngeal stenosis were presented. In 3 cases laryngeal web was recognised which arises after endoscopical removal of infant papilloma. The scar after laser chordectomy due to carcinoma of the larynx occurred in remaining 3 patients. All presented patients simultaneously were undergoing removal of the lesion endoscopically and insertion of silastic separator. Aim Respiratory and phonatory function assessment in patients who were operated because of the laryngeal stenosis was the aim of this study. Methods Treatment effectiveness was estimate on the basis of pre- and postoperative spirometry with flow – volume loop and postoperative phoniatric examination. Ventilatory function was analysis on the basis of the following parameters: PIF, FEV1, FIV1, PEF, FVC. Phoniatric examination was performed after 2 months of outpatient observation and rehabilitation. It consisted of subjective voice assessment using GRBAS scale, videolaryngostroboscopy and assessment of the phonation time. Results Some of the analysed parameters especially in patients with posterior stenosis were significantly better after surgery. Phoniatric rehabilitation after surgery caused improvement of voice quality and phonatory function of the larynx. Conclusion Thanks to insertion of silastic separator good phoniatric function and ventilation efficiency are possible.

Leczenie chirurgiczne przewlekłego zapalenia zatok przynosowych u dzieci

Summary Introduction Chronic sinusitis presents important problem in children. General approach in chronic sinusitis in children consists of: findings the proper diagnosis, optimal pharmacotherapy (oral or intravenous antibiotics), treatment coexisting allergic or systemic diseases and considering employing surgical treatment. The main surgical procedures in the treatment of chronic sinusitis in children are adenoidectomy and functional endoscopic sinus surgery (FESS). Material and methods 32 children with chronic sinusitis treated in ENT Department Silesian Medical University in Zabrze in the years 2000–2005 were presented in this study. 26 patients were treated surgically and 6 children by pharmacotherapy. In the surgically treated patients we performed 10 Functional Endoscopic Sinus Surgery, 4 unilateral and 8 bilateral sinusoscopy of maxillary sinus, and in 4 cases we removed choanal polyps. Results In the group of 26 surgically treated children we did not observed the recurrence of symptoms in the 24 months follow-up period.

CO2 laser treatment of laryngeal stenoses after supracricoid laryngectomies

We have read a very interesting paper “CO2 laser treatment of laryngeal stenoses after reconstructive laryngectomies with cricohyoidopexy, cricohyoidoepiglottopexy or tracheohyoidoepiglottopexy”. Our experience with reconstructive laryngectomies dates back to 1990. We have performed 82 reconstructive laryngectomies with CHP and CHEP. We have not had any experience with THEP [1]. In our series post-operative stenosis occurred in ten patients (12%). In majority of stenoses the neo-laryngeal mucosal Xap was recognized in six cases, semi-circumferential stenosis in three cases and one patient had synechia between epiglottis and arytenoid. They were treated with 23 laser CO2 procedures (mean 2,3 procedures, range 1–4 procedures). All operations were performed under general anesthesia with typical Kleinsasser set, together with a surgical microscope Zeiss S 21 with a focal lens of 400 mm connected to a micromanipulator. The continuous mode of 5–12 W was used. All patients received dexamethasone sodium phosphate (Dexaven) 4 mg every 8 h over a period of 48 h. Oral antibiotic 1 g cefuroxime sodium was continued for 10 days. Also methyl prednisolone was administered locally [2]. Unfortunately we have not had experience with mitomycin C yet. The main problem in the case of reconstructive laryngectomy is the lack of the rigid structures and the possibility to collapse, especially during sleep. It causes more problems which are technically diYcult in external approach procedure. It is more diYcult in comparison to widening neolaryngeal lumen after vertical laryngectomies. That is why we would like to recommend CO2 procedure with silastic separator or Montgomery tube insertion postoperatively. Patient B.C., 45-year-old female, after RL with CHP was treated with CO2 laser due to neo-laryngeal mucosal Xap. As a result of the operation the progression of stenosis was observed. Trying to avoid the external approach procedure the CO2 laser technique was repeated with subsequent selfmade silastic separator insertion. It was inserted endoscopically and Wxed with vicryl 2.0 sutures with Lichtenberger endolaryngeal needle carrier and tied bilaterally at the neck [3] (Fig. 1).

Gender-related voice problems in transsexuals - therapeutical demands.

The paper presents a case study of a transsexual patient who underwent a voice pitch elevation surgery performed in Poland for the first time. The human voice is a reflection of the working of hormones and human psyche. This fact is of particular importance in transsexualism, a disorder consisting in incongruence between the individuals biological sex and their identified gender. For many transsexual people, especially of the MTF (male to female) type, who have undergone hormonal and surgical sex change, the voice still presents a major problem, causing difficulties in everyday life. Hormonal treatment does not influence feminisation of the larynx. In the described MTF case, the patients low androphonic voice was perceived as a male voice. In order to feminise the patients voice a phonosurgical procedure was performed: the length of the vibrating portion of the vocal folds was shortened by over 50% of their total length by means of suturing of the anterior part of the vocal fold. As a result of the surgical treatment the pitch of voice was raised considerably, with F0 of spoken voice increased from 109 Hz to 209 Hz. The voice range also changed towards female tones, from 59-146 Hz to 148-343 Hz. Pitch elevation positively influenced the patients subjective voice assessment: total score of the Voice Handicap Index (VHI) improved from 99 to 19 points, and the score of its emotional sub-scale: 39 and 2 points, respectively. The described case of a surgical male-to-female voice change presents one of the dilemmas faced by modern medicine. (Endokrynol Pol 2016; 67 (4): 452-455).

Jakość głosu u górników po urazie inhalacyjnym górnych dróg oddechowych w wyniku wybuchu metanu

Summary The job as a coal-miner exposes to the great risk. One of the most dangerous health hazard is a burn/inhalation injury during the methane explosion. The victims undergo physical trauma, effect of high temperature and inhalation of toxic gases and products of incomplete combustion. As a result of inhalation injury both, upper and lower airways are affected. The aim of the study was to analyse the relationship between burn/inhalation injury and quality of voice in affected coal-miners. A group of 23 patients (men) in age from 28 to 59 (mean 38.5) 3 years after burn/inhalation injury participated in this study. The voice evaluation based on ENT examination, videlaryngostroboscopy, acoustic analysis, MPT parameter and GRBAS analysis was performed. The special control group of coal-miners served as a control. On the basis of the subjective evaluation and the objective acoustic analysis, aerodynamic parameter and videlaryngostroboscopy the worse quality of voice in the group of injured coalminers was shown in comparison to the control group. No substantial correlation between the acoustic parameters, MPT parameter and ventilating rates was found.The job as a coal-miner exposes to the greatest risk. One of the most dangerous health hazard is a burn/inhalation injury during the methane explosion. The victims undergo physical trauma, effect of high temperature and inhalation of toxic gases and products of incomplete combustion, As a result of inhalation injury both, upper and lower airways are affected. The aim of the study was to analyse the relationship between burn/inhalation injury and quality of voice in affected coal-miners. A group of 23 patients (men) in age from 28 to 59 (mean 38.5) 3 years after burn/inhalation injury participated in this study. The voice evaluation based on ENT examination, videlaryngostroboscopy, acoustic analysis, MPT parameter and GRBAS analysis was performed. The special control group of coal-miners served as a control. On the basis of the subjective evaluation and the objective acoustic analysis, aerodynamic parameter and videlaryngostroboscopy the worse quality of voice in the group of injured coalminers was shown in comparison to the control group. No substantial correlation between the acoustic parameters, MPT parameter and ventilating rates was found.

Test eferentny ślimaka – czułość i swoistość metodyEfferent suppression test – sensitivity and specificity☆

Summary Introduction The amplitude of click evoked otoacoustic emissions can be suppressed (reduced) with contralateral acoustic stimulation (CAS). This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell function. One commonly used test of medial olivocochlear (MOC) function in humans involves measuring the degree of suppression of ipsilateral otoacoustic emissions (OAEs) by CAS. This effect is called contralateral suppression, efferent effect or olivocochlear reflex. Aim of the study. The objective of this study was to measure cut-off level of contralateral suppression, sensitivity and specificity of the efferent test. Material and methods To evaluate the function of MOC system click evoked otoacoustic emissions (CEOAEs) with and without continuous contralateral broadband noise (BBN) stimulation were recorded in 14 patients with multiple sclerosis, 16 patients with unilateral cerebello-pontine angle tumor and control group matched for age and gender. BBN was presented at 50 dB SL and otoacoustic emissions were recorded in response to nonlinear clicks at 70 +/− 3 dB SPL. Results The cut-off level was established at −1.4 dB. For 1.4 dB cut-off level of contralateral suppression the sensitivity of the efferent test was 90% and specificity was 70%. Conclusions To conclude, assessment of efferent suppression may be a useful addition to the battery test employed in the investigation of multiple sclerosis and cerebello-pontine angle tumors. The MOC suppression test may provide a tool for an early diagnosis of the brainstem pathology.INTRODUCTION The amplitude of click evoked otoacoustic emissions can be suppressed (reduced) with contralateral acoustic stimulation (CAS). This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell function. One commonly used test of medial olivocochlear (MOC) function in humans involves measuring the degree of suppression of ipsilateral otoacoustic emissions (OAEs) by CAS. This effect is called contralateral suppression, efferent effect or olivocochlear reflex. Aim of the study. The objective of this study was to measure cut-off level of contralateral suppression, sensitivity and specificity of the efferent test. MATERIAL AND METHODS To evaluate the function of MOC system click evoked otoacoustic emissions (CEOAEs) with and without continuous contralateral broadband noise (BBN) stimulation were recorded in 14 patients with multiple sclerosis, 16 patients with unilateral cerebello-pontine angle tumor and control group matched for age and gender. BBN was presented at 50 dB SL and otoacoustic emissions were recorded in response to nonlinear clicks at 70 +/- 3 dB SPL. RESULTS The cut-off level was established at -1.4 dB. For 1.4 dB cut-off level of contralateral suppression the sensitivity of the efferent test was 90% and specificity was 70%. CONCLUSIONS To conclude, assessment of efferent suppression may be a useful addition to the battery test employed in the investigation of multiple sclerosis and cerebello-pontine angle tumors. The MOC suppression test may provide a tool for an early diagnosis of the brainstem pathology.

Test eferentny ślimaka – czułość i swoistość metody

Summary Introduction The amplitude of click evoked otoacoustic emissions can be suppressed (reduced) with contralateral acoustic stimulation (CAS). This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell function. One commonly used test of medial olivocochlear (MOC) function in humans involves measuring the degree of suppression of ipsilateral otoacoustic emissions (OAEs) by CAS. This effect is called contralateral suppression, efferent effect or olivocochlear reflex. Aim of the study. The objective of this study was to measure cut-off level of contralateral suppression, sensitivity and specificity of the efferent test. Material and methods To evaluate the function of MOC system click evoked otoacoustic emissions (CEOAEs) with and without continuous contralateral broadband noise (BBN) stimulation were recorded in 14 patients with multiple sclerosis, 16 patients with unilateral cerebello-pontine angle tumor and control group matched for age and gender. BBN was presented at 50 dB SL and otoacoustic emissions were recorded in response to nonlinear clicks at 70 +/− 3 dB SPL. Results The cut-off level was established at −1.4 dB. For 1.4 dB cut-off level of contralateral suppression the sensitivity of the efferent test was 90% and specificity was 70%. Conclusions To conclude, assessment of efferent suppression may be a useful addition to the battery test employed in the investigation of multiple sclerosis and cerebello-pontine angle tumors. The MOC suppression test may provide a tool for an early diagnosis of the brainstem pathology.INTRODUCTION The amplitude of click evoked otoacoustic emissions can be suppressed (reduced) with contralateral acoustic stimulation (CAS). This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell function. One commonly used test of medial olivocochlear (MOC) function in humans involves measuring the degree of suppression of ipsilateral otoacoustic emissions (OAEs) by CAS. This effect is called contralateral suppression, efferent effect or olivocochlear reflex. Aim of the study. The objective of this study was to measure cut-off level of contralateral suppression, sensitivity and specificity of the efferent test. MATERIAL AND METHODS To evaluate the function of MOC system click evoked otoacoustic emissions (CEOAEs) with and without continuous contralateral broadband noise (BBN) stimulation were recorded in 14 patients with multiple sclerosis, 16 patients with unilateral cerebello-pontine angle tumor and control group matched for age and gender. BBN was presented at 50 dB SL and otoacoustic emissions were recorded in response to nonlinear clicks at 70 +/- 3 dB SPL. RESULTS The cut-off level was established at -1.4 dB. For 1.4 dB cut-off level of contralateral suppression the sensitivity of the efferent test was 90% and specificity was 70%. CONCLUSIONS To conclude, assessment of efferent suppression may be a useful addition to the battery test employed in the investigation of multiple sclerosis and cerebello-pontine angle tumors. The MOC suppression test may provide a tool for an early diagnosis of the brainstem pathology.