Using the new Continuous Loop Averaging Deconvolution (CLAD) acquisition technique, it is now pos... more Using the new Continuous Loop Averaging Deconvolution (CLAD) acquisition technique, it is now possible to record evoked potentials at very high stimulation rates. The CLAD technique allows the experimenter to tailor the stimulation sequences to fit his specific application to unwrap overlapping responmses at high rates. CLAD sequences can be designed to reduce physiological adaptation effects and to control the noise shaping effect of the deconvolution process. This study shows examples of promising clinical applications of CLAD using Electrocochleograms (ECochGm), Auditory Brainstem Responses (ABR), Auditory Middle Latency Responses (AMLR): In the first example CLAD was applied to record TransTympanic (TT) ECochGm at conventional and high rates in Meniere’s patients. These high-rate ECochGs revealed distinctive physiological patterns not previously observed at conventional rates. Regarding the ABRs, custom CLAD sequences were designed to simultaneously provide high Signal to Noise ...
Guidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial... more Guidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial. In this paper we reviewed our experience with patients with NF2 for the results of surgical treatment with particular reference to hearing and facial nerve preservation. We included in the study 30 patients (16 women and 14 men) with the diagnosis of NF2 treated in our department between 1998 and 2014 who underwent surgery for vestibular schwannoma removal with a follow-up for at least 1 year. In 3 cases, the vestibular schwannomas were unilateral. Six patients with bilateral vestibular schwannomas underwent unilateral procedure. Therefore, 51 acoustic tumors were studied in 30 patients. No operative death we noted. Significant deterioration to the non-functional level occurred in 19 out of 22 cases with well-preserved preoperative hearing. Only three ears maintained their preoperative good hearing. Hearing was preserved in cases of small schwannoma not exceeding 2cm. Among 21 patients who underwent bilateral operations hearing was preserved in 3 out of 7 cases when smaller tumor or better hearing level side was attempted at first surgery. In contrary none of the 14 patients retained hearing when the first operation concerned the worse-hearing ear. Among 14 tumors up to 2cm there was only one case of moderately severe facial nerve dysfunction (House-Brackmann Grade IV) in the long follow-up. Early surgical intervention for vestibular schwannoma in NF2 patient is a viable management strategy to maintain hearing function and preserve facial nerve function.
Objectives: Since the 1940s, various attempts have been made to treat peripheral tinnitus by way ... more Objectives: Since the 1940s, various attempts have been made to treat peripheral tinnitus by way of intratympanic (i.t.) injection. However, in spite of its compelling advantages, namely the highly targeted drug delivery with minimal systemic exposure, this administration route did not find widespread use so far primarily due to the lack of specific and effective medication. In recent years the i.t. approach saw renewed interest thanks to a better understanding of local pharmacokinetics and the development of new drug treatments for inner ear disorders such as tinnitus. While usually considered a safe and straightforward procedure by otolaryngologists, there has been a dearth of comprehensive safety data on i.t. injections. As part of the clinical development of AM‐ 101, a small molecule NMDA receptor antagonist for i.t. treatment of acute inner ear tinnitus, procedure related safety outcomes could be systematically collected and analysed. Methods: Safety outcome data from 2 complet...
Inhibition of cochlear N-methyl-D-aspartate (NMDA) receptors with AM-101, a small molecule antago... more Inhibition of cochlear N-methyl-D-aspartate (NMDA) receptors with AM-101, a small molecule antagonist delivered by intratympanic injection, represents a novel approach to treat acute tinnitus triggered by glutamate excitotoxicity. An earlier double-blind, randomized, placebo-controlled phase II clinical trial (TACTT0) had demonstrated a significant and dose-dependent improvement in tinnitus triggered by acute acoustic trauma or otitis media from baseline to day 90. A second phase II trial (TACTT1) now sought to evaluate the most appropriate dose regimen for this treatment. Outcomes from the TACTT1 trial showed no significant difference in tinnitus improvement between a single-dose treatment and a dose regimen comprising three doses over 2 weeks. Taken together, three injections over 3 consecutive days showed the best results in the two phase II trials, suggesting that repeated and concentrated inhibition of cochlear NMDA receptors provides best treatment effects, while keeping the p...
ABSTRACT In recent years the number of frontal sinus trauma is increasing due to a large number o... more ABSTRACT In recent years the number of frontal sinus trauma is increasing due to a large number of traffic accidents, doing sports and fights. Frontal sinus trauma occurs in 5–12% of facial skeleton fractures. Complications of sinusitis are divided into early complications, till 6 weeks from the trauma and late complications which occur after this period of time. In this paper we described a 33-year-old patient, who suffered from acute sinusitis complicated with orbital abscess of right eye. Nine years before this disease he sustained an injury of head in which anterior and inferior wall of right frontal sinus were broken. The patient underwent a functional endoscopic sinus surgery with enlargement of the frontal sinus ostium and across external approach, through bone defect in inferior wall of frontal sinus, the frontal sinus and orbital abscess were drainaged. The patient healed well within 2 weeks. Non-complicated fractures of facial skeleton can be dangerous, and through them the inflammation can spread to adjacent tissues. Reconstruction of the bone defects should be taken into consideration in such cases.
To evaluate the efficacy and safety of AM-111, a c-Jun N-terminal Kinase (JNK) ligand, in patient... more To evaluate the efficacy and safety of AM-111, a c-Jun N-terminal Kinase (JNK) ligand, in patients with acute sensorineural hearing loss (ASNHL). Prospective, double-blind, randomized, placebo-controlled study with follow-up visits on Days 3, 7, 30, and 90. Twenty-five European sites (academic tertiary referral centers, private ENT practices). Approximately 210 patients aged 18 to 61 years presenting within 48 hours after acute acoustic trauma or idiopathic sudden sensorineural hearing loss with mean hearing loss of 30 dB or greater at the 3 most affected contiguous test frequencies. Single-dose intratympanic injection of AM-111 (0.4 or 2.0 mg/ml) or placebo; optionally, oral prednisolone if hearing improvement was less than 10 dB at Day 7. Efficacy was assessed by absolute hearing improvement (primary end point, Day 7), percentage hearing improvement, complete hearing recovery, speech discrimination improvement, and complete tinnitus remission. Safety was evaluated by the frequency of clinically relevant hearing deterioration and adverse events. The study failed to demonstrate a treatment benefit for the entire study population because mild-to-moderate ASNHL cases showed unexpectedly strong spontaneous recovery. In severe-to-profound ASNHL patients (threshold ≥60 dB), AM-111 0.4 mg/ml showed statistically significant, clinically relevant, and persistent improvements in hearing and speech discrimination and higher tinnitus remission compared with placebo. The study drug and the intratympanic injections were well tolerated. The study established proof of concept for AM-111 in the treatment of severe-to-profound ASNHL. Control for spontaneous hearing recovery is essential for ASNHL studies.
Local application of dexamethasone to the round window (RW) niche prevents cochlear damage caused... more Local application of dexamethasone to the round window (RW) niche prevents cochlear damage caused by local reversible ischemia. Cochlear ischemia induced by internal auditory artery (IAA) compression/stretching is thought to cause postoperative sensory hearing loss after attempted hearing preservation removal of acoustic neuroma tumors. Dexamethasone administered to the RW niche traveling through the membrane to the cochlear fluids may prevent ischemic damage. Ten young albino rabbits were used for this study. Ischemic episodes were induced by compressing the IAA. Laser Doppler cochlear blood flow was measured using a probe positioned at the RW niche. Transtympanic electrocochleography was measured at 4, 8, and 12 kHz. In 5 test ears, dexamethasone was administered topically at the RW for approximately 50 minutes before the IAA compressions, whereas in 5 control ears, saline was applied in the same way. Each ear underwent one 10-minute IAA compression with a 60-minute postischemic period of transtympanic electrocochleography monitoring. In both control- and dexamethasone-treated ears, ischemic episodes measured by Laser Doppler cochlear blood flow were comparable. Fifty minutes after IAA decompression, in dexamethasone-pretreated ears, cochlear microphonic and compound action potential amplitudes at all test frequencies were 10 to 15% less reduced than those in control ears. Compound action potential latencies in dexamethasone-pretreated ears resulted in shorter latency delay than in control ears. The RW seems to be an efficacious route for the administration of dexamethasone into the inner ear. Dexamethasone showed a protective effect on cochlear function after local ischemia. Transtympanic electrocochleography was found to be a sufficient and effective tool in monitoring hearing.
ABSTRACT Introduction To assess an effect of cochleostomy on hearing threshold in guinea pigs. Ma... more ABSTRACT Introduction To assess an effect of cochleostomy on hearing threshold in guinea pigs. Material and methods The authors performed animal experiments using five 3-month-old guinea pigs. Before experiment hearing threshold were evaluated. Surgery involved access to the temporal bone by a post-auricular incision. After a wide opening of the bulla cochleostomy was created (10 000 turn/min, diamond bur of 0,8 mm diameter). Hearing threshold was identified on the basis of presence of wave V in auditory brainstem responses (ABR) for click and frequency-specific stimulation. Also morphology and latency changes for wave V for this stimulation was assesed. Hearing status was evaluated before, just after and 1-, 2-, and 4-weeks after surgery. For surgical procedure and ABR examination all animals were anesthetized with an intramuscular injection of ketamine (50 mg/kg) mixed with xylazine (9 mg/kg) in the supplemental doses. After surgery the animal was treated by antibioticoterapy for 3 days – Enrofloksacyna 0,3 ml subcutaneouly and analgesic – Tolfedine 0,05 mg in second day. Results Four week observation of ABR morphology and hearing thresholds for click and frequency-specific stimulation of 100 dB SPL intensity showed only temporary changes confirming that cochleostomy did not affect cochlear function. Conclusions The correctly performed cochleostomy in guinea pigs did not affect persistently the cochlear function indicating that such an option of CI electrode insertion in patients is safe.
Evaluation of usefulness new non-contact method--Laser Doppler vibrometry (LDV) in measurements o... more Evaluation of usefulness new non-contact method--Laser Doppler vibrometry (LDV) in measurements of movability of ossicular chain during second look operation was aim of the study. We would like answer to questions: 1. Is LDV helpful in intraoperative conditions? 2. Which measurements points have the largest practical value? 3. Which measured parameters could be used to determination of effectiveness ossicular chain reconstruction? In experiment there were taken 3 fresh temporal bones kept in 0,9% NaCl. In first stage were executed: antromastoidectomy with wide tympanotomy. The ossicular chain movability investigation was conducted on: back branch of stapes, front branch of stapes, round window, umbo of eardrum. Laser Doppler Vibrometer was used to measurement ossicular chain's movability. ER-2 loudspeakers were generated wave: 1000 Hz, 2000 Hz, 4000Hz. In second stage were executed: Malleus-Stapes Assembly (MSA) ossicular chain's reconstruction and repeated investigation in measured points. The most convenient points to measurement were respectively: back branch of stapes, front branch of stapes, umbo of eardrum. In two cases round window was placed in deep niche and was partly covered by facial nerve. MSA performance didn't influence accessibility of measuring points. Theresholds of measured point's movability was useful to evaluation of reconstruction. Back branch of stapes, front branch of stapes and umbo of eardrum are useful to intraoperatve measurements ossicular chain movability. Delimitation thresholds of ossicular chain movability can help in reconstruction's evaluation. After next experiments LDV can be use in practice-intraoperative.
ABSTRACT Introduction The main tumor of cerebellopontine angle are vestibular schwannoma (80–90%)... more ABSTRACT Introduction The main tumor of cerebellopontine angle are vestibular schwannoma (80–90%). According to National Institute of Health Consensus Development Conference the best treatment method is microsurgery. There are three principal surgical approaches: translabyrinthin, retrosigmoid and middle fossa. Only the latter two approaches provide the possibility of hearing preservation. Aim Technique of surgery and postoperative morbidity after MFA. Material and methods 39 patients (40 tumor) suffered from tumor of cerebellopontine angle, operated by using middle fossa approach in years 1998–2007. We evaluate hearing preservation and function of facial nerve and others postoperative morbidity. Results 22.5% of patients has hearing impairment and 32.5% has facial weakness. By individual cases we observed: CSF leak, meningitis, corneal ulceration, ischialgia, wound bleeding and venue thrombosis. 1/3 of patients suffered from headache and disequilibrium and 1/6 suffered from tinnitus. Conclusion According to NIH middle fossa approach is one of three possible approaches in microsurgery of cerebellopontine angle tumors. There is possible total tumor removal with hearing preservation. Monitoring of facial and cochlear nerve during operation is recommended.
Mucocele, though is a common lesion, rarely penetrates to the surrounding intra- and extracranial... more Mucocele, though is a common lesion, rarely penetrates to the surrounding intra- and extracranial spaces. We describe the case of 45-year-old male with 2 years history of a chronic left nasal obstruction and a concentric visual field deficit in the left eye as the only manifestations. Diagnostic CT and MRI imaging revealed a mucocele originating from the posterior ethmoid and sphenoid sinuses and penetrating intracranially to the anterior and middle cranial fossae and extracranially to the pterygopalatine fossa and the parapharyngeal space. This extensive localization appears to be an extremely rare entity, which, to our knowledge, has not been described in the English literature yet. The clinical features and a literature review are also presented.
The most important for the diagnosis of vestibular schwannoma is MRI technic, which allows assess... more The most important for the diagnosis of vestibular schwannoma is MRI technic, which allows assessing its size and shape. The gold diagnostic standard includes also PTA, SD and ABR, nystagmography with calorics and VEMP. Nystagmography with calorics reflects the status of superior vestibular nerve. The sensitivity of calorics amounts to 61–87%. VEMPs reflect the status of interior vestibular nerve; its sensitivity is about 80%. The greatest diagnostic sensitivity shows ABR method, which is estimated for about 96–99%.analysis of PTA, ABR, VEMP and calorics results in smaller G1(≤10 mm) and greater G2 (>11 mm) tumors, and assessement of influence of the size of the tumor for auditory and vestibular function.PTA, ABR, VEMP and calorics results performed in 33 patients with CPA tumors.CPA tumors originate from inferior vestibular nerve in most cases; there is no statistical PTA differences in G1 and G2 groups; sensitivity of calorics (G1 53%, G2 95%), and ABR (G1 75%, G2 100%) depend on tumor size and tumor size has significant influence on results of both of these methods; sensitivity of VEMPs is similar in G1 and G2 groups (83% and 89%).there is no strict correlation between tumor origin and calorics and ABR results; greatest sensitivity in our material show VEMP, what is probably results of frequent tumors origin from inferior vestibular nerve.
The role of medial efferent system in regulating outer hair cell function has been studied by man... more The role of medial efferent system in regulating outer hair cell function has been studied by many investigators. Usually narrow band noise or white noise as contralateral stimulation (CS) suppressors have been used and changes in OAE amplitudes estimated. Thirty children aged 6-15 years (mean 12.5 +/- 4.7), without any changes in tonal and impedance audiometry and with negative history regarding otiatric diseases were examined. Transient evoked otoacoustic emissions (TEOAE) were recorded using ILO 92 Otodynamics Analyser. CS was performed using 1.0 kHz and 2.0 kHz continuous pure tones of 30 dB SL or 50 dB SL. Effects of CS on TEOAE evoked by click of 80, 70 and 60 dB SPL were investigated. TEOAE analysis included assessment of TEOAE amplitude of half octave frequency bandwidth (HOFBW-1.0; HOFBW-1.5; HOFBW-2.0; HOFBW-3.0 and HOFBW-4.0 kHz) and 0.8 kHz frequency bandwidth (0.8-FBW) amplitudes centred at 1.0; 2.0; 3.0; 4.0 and 5.0 kHz. TEOAE amplitude recorded for stimuli 80, 70 and 60 dB SPL without CS decreased: mean values respectively 6.1 +/- 4.2; 5.4 +/- 4.5 and 3.3 dB SPL +/- 4.3. CS effect on TEOAE was observed for all CS options, however, larger suppressive effect was recorded on TEOAE elicited by 70 dB SPL stimulus using 1 kHz/50 dB SL tone as a suppressor and on TEOAE elicited by 60 dB SPL stimulus using 2 kHz/50 dB SL tone as a suppressor. HOFBW and 0.8-FBW analyses showed the association between the frequency/intensity of the suppressors and decreasing of amplitudes of adequate frequency bands. It is concluded that the described method of investigating of the medial olivocochlear efferent system seems to be sensitive and confirms frequency-dependent suppressive effect on OAE.
Round window's movability measurements with helping of LDV in evaluation of ossicular chain funct... more Round window's movability measurements with helping of LDV in evaluation of ossicular chain functioning.Quantitive evaluation of round window movability in normal conditions and after malleus stapes assembly reconstruction were aims of the study.In the experiment there were taken 10 non-frozen temporal bones harvested within 48 hours.Temporal bones specimens were prepared like in closed technique with antromastoidectomy and large posterior tympanotomy. Hearing system before and after MSA reconstruction were evaluated by measurement of round window movement. Measurements were performed at four frequencies: 1000 Hz, 2000 Hz, 4000 Hz, 8000 Hz.In the normal ossicular chain the biggest movability were stated at frequency of 1 kHz. After reconstruction at all frequencies measurements were significantly worse. In reconstructed ears the highest movabilities were stated at frequencies 2000 Hz and 4000 Hz.Round window movability could be measured by Laser Doppler Vibrometry in posterior tympanotomy approach. Before reconstruction the biggest movability were evaluated at 1000 Hz and after MSA at 2000 Hz.
We report 2 cases (52 and 29-year-old men) of CG in the petrous apex we treated in 2004–2006. We ... more We report 2 cases (52 and 29-year-old men) of CG in the petrous apex we treated in 2004–2006. We also review the literature and discus the mechanism of development of CG and the treatment of this lesion.Cholesterol granuloma (CG) is a chronic inflammatory process with associated foreign body reaction to hemorrhage-related cholesterol crystals. Although CG is found in various organs the temporal bone is the most common site of detection. Numerous ethiopathological hypotheses have been proposed but most authorities support the concept of air cell tract blockage in well pneumatized petrous apex. Obstruction of the air cells leads to rupture of blood vessels and hemorrhage. Red blood cell degradation into cholesterol crystals produces a foreign body giant-cell reaction with progressive accumulation of typical brownish glistening fluid. Clinically, this lesion can produce sensorineural hearing loss, tinnitus, hemifacial spasm, facial numbness and trigeminal neuralgia. Cholesteatoma is the main lesion to distinguish from CG. On MRI studies, CG appears with a high signal on both T1- and T2-weighted sequences, cholesteatoma appear bright only on T2-weighted ones. Goal of the surgery is to create a drainage and ventilation of the affected area to prevent recurrence. Several alternative approaches to the petrous apex have been described.12–18 months follow up shows no clinical signs of recurrence.
Using the new Continuous Loop Averaging Deconvolution (CLAD) acquisition technique, it is now pos... more Using the new Continuous Loop Averaging Deconvolution (CLAD) acquisition technique, it is now possible to record evoked potentials at very high stimulation rates. The CLAD technique allows the experimenter to tailor the stimulation sequences to fit his specific application to unwrap overlapping responmses at high rates. CLAD sequences can be designed to reduce physiological adaptation effects and to control the noise shaping effect of the deconvolution process. This study shows examples of promising clinical applications of CLAD using Electrocochleograms (ECochGm), Auditory Brainstem Responses (ABR), Auditory Middle Latency Responses (AMLR): In the first example CLAD was applied to record TransTympanic (TT) ECochGm at conventional and high rates in Meniere’s patients. These high-rate ECochGs revealed distinctive physiological patterns not previously observed at conventional rates. Regarding the ABRs, custom CLAD sequences were designed to simultaneously provide high Signal to Noise ...
Guidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial... more Guidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial. In this paper we reviewed our experience with patients with NF2 for the results of surgical treatment with particular reference to hearing and facial nerve preservation. We included in the study 30 patients (16 women and 14 men) with the diagnosis of NF2 treated in our department between 1998 and 2014 who underwent surgery for vestibular schwannoma removal with a follow-up for at least 1 year. In 3 cases, the vestibular schwannomas were unilateral. Six patients with bilateral vestibular schwannomas underwent unilateral procedure. Therefore, 51 acoustic tumors were studied in 30 patients. No operative death we noted. Significant deterioration to the non-functional level occurred in 19 out of 22 cases with well-preserved preoperative hearing. Only three ears maintained their preoperative good hearing. Hearing was preserved in cases of small schwannoma not exceeding 2cm. Among 21 patients who underwent bilateral operations hearing was preserved in 3 out of 7 cases when smaller tumor or better hearing level side was attempted at first surgery. In contrary none of the 14 patients retained hearing when the first operation concerned the worse-hearing ear. Among 14 tumors up to 2cm there was only one case of moderately severe facial nerve dysfunction (House-Brackmann Grade IV) in the long follow-up. Early surgical intervention for vestibular schwannoma in NF2 patient is a viable management strategy to maintain hearing function and preserve facial nerve function.
Objectives: Since the 1940s, various attempts have been made to treat peripheral tinnitus by way ... more Objectives: Since the 1940s, various attempts have been made to treat peripheral tinnitus by way of intratympanic (i.t.) injection. However, in spite of its compelling advantages, namely the highly targeted drug delivery with minimal systemic exposure, this administration route did not find widespread use so far primarily due to the lack of specific and effective medication. In recent years the i.t. approach saw renewed interest thanks to a better understanding of local pharmacokinetics and the development of new drug treatments for inner ear disorders such as tinnitus. While usually considered a safe and straightforward procedure by otolaryngologists, there has been a dearth of comprehensive safety data on i.t. injections. As part of the clinical development of AM‐ 101, a small molecule NMDA receptor antagonist for i.t. treatment of acute inner ear tinnitus, procedure related safety outcomes could be systematically collected and analysed. Methods: Safety outcome data from 2 complet...
Inhibition of cochlear N-methyl-D-aspartate (NMDA) receptors with AM-101, a small molecule antago... more Inhibition of cochlear N-methyl-D-aspartate (NMDA) receptors with AM-101, a small molecule antagonist delivered by intratympanic injection, represents a novel approach to treat acute tinnitus triggered by glutamate excitotoxicity. An earlier double-blind, randomized, placebo-controlled phase II clinical trial (TACTT0) had demonstrated a significant and dose-dependent improvement in tinnitus triggered by acute acoustic trauma or otitis media from baseline to day 90. A second phase II trial (TACTT1) now sought to evaluate the most appropriate dose regimen for this treatment. Outcomes from the TACTT1 trial showed no significant difference in tinnitus improvement between a single-dose treatment and a dose regimen comprising three doses over 2 weeks. Taken together, three injections over 3 consecutive days showed the best results in the two phase II trials, suggesting that repeated and concentrated inhibition of cochlear NMDA receptors provides best treatment effects, while keeping the p...
ABSTRACT In recent years the number of frontal sinus trauma is increasing due to a large number o... more ABSTRACT In recent years the number of frontal sinus trauma is increasing due to a large number of traffic accidents, doing sports and fights. Frontal sinus trauma occurs in 5–12% of facial skeleton fractures. Complications of sinusitis are divided into early complications, till 6 weeks from the trauma and late complications which occur after this period of time. In this paper we described a 33-year-old patient, who suffered from acute sinusitis complicated with orbital abscess of right eye. Nine years before this disease he sustained an injury of head in which anterior and inferior wall of right frontal sinus were broken. The patient underwent a functional endoscopic sinus surgery with enlargement of the frontal sinus ostium and across external approach, through bone defect in inferior wall of frontal sinus, the frontal sinus and orbital abscess were drainaged. The patient healed well within 2 weeks. Non-complicated fractures of facial skeleton can be dangerous, and through them the inflammation can spread to adjacent tissues. Reconstruction of the bone defects should be taken into consideration in such cases.
To evaluate the efficacy and safety of AM-111, a c-Jun N-terminal Kinase (JNK) ligand, in patient... more To evaluate the efficacy and safety of AM-111, a c-Jun N-terminal Kinase (JNK) ligand, in patients with acute sensorineural hearing loss (ASNHL). Prospective, double-blind, randomized, placebo-controlled study with follow-up visits on Days 3, 7, 30, and 90. Twenty-five European sites (academic tertiary referral centers, private ENT practices). Approximately 210 patients aged 18 to 61 years presenting within 48 hours after acute acoustic trauma or idiopathic sudden sensorineural hearing loss with mean hearing loss of 30 dB or greater at the 3 most affected contiguous test frequencies. Single-dose intratympanic injection of AM-111 (0.4 or 2.0 mg/ml) or placebo; optionally, oral prednisolone if hearing improvement was less than 10 dB at Day 7. Efficacy was assessed by absolute hearing improvement (primary end point, Day 7), percentage hearing improvement, complete hearing recovery, speech discrimination improvement, and complete tinnitus remission. Safety was evaluated by the frequency of clinically relevant hearing deterioration and adverse events. The study failed to demonstrate a treatment benefit for the entire study population because mild-to-moderate ASNHL cases showed unexpectedly strong spontaneous recovery. In severe-to-profound ASNHL patients (threshold ≥60 dB), AM-111 0.4 mg/ml showed statistically significant, clinically relevant, and persistent improvements in hearing and speech discrimination and higher tinnitus remission compared with placebo. The study drug and the intratympanic injections were well tolerated. The study established proof of concept for AM-111 in the treatment of severe-to-profound ASNHL. Control for spontaneous hearing recovery is essential for ASNHL studies.
Local application of dexamethasone to the round window (RW) niche prevents cochlear damage caused... more Local application of dexamethasone to the round window (RW) niche prevents cochlear damage caused by local reversible ischemia. Cochlear ischemia induced by internal auditory artery (IAA) compression/stretching is thought to cause postoperative sensory hearing loss after attempted hearing preservation removal of acoustic neuroma tumors. Dexamethasone administered to the RW niche traveling through the membrane to the cochlear fluids may prevent ischemic damage. Ten young albino rabbits were used for this study. Ischemic episodes were induced by compressing the IAA. Laser Doppler cochlear blood flow was measured using a probe positioned at the RW niche. Transtympanic electrocochleography was measured at 4, 8, and 12 kHz. In 5 test ears, dexamethasone was administered topically at the RW for approximately 50 minutes before the IAA compressions, whereas in 5 control ears, saline was applied in the same way. Each ear underwent one 10-minute IAA compression with a 60-minute postischemic period of transtympanic electrocochleography monitoring. In both control- and dexamethasone-treated ears, ischemic episodes measured by Laser Doppler cochlear blood flow were comparable. Fifty minutes after IAA decompression, in dexamethasone-pretreated ears, cochlear microphonic and compound action potential amplitudes at all test frequencies were 10 to 15% less reduced than those in control ears. Compound action potential latencies in dexamethasone-pretreated ears resulted in shorter latency delay than in control ears. The RW seems to be an efficacious route for the administration of dexamethasone into the inner ear. Dexamethasone showed a protective effect on cochlear function after local ischemia. Transtympanic electrocochleography was found to be a sufficient and effective tool in monitoring hearing.
ABSTRACT Introduction To assess an effect of cochleostomy on hearing threshold in guinea pigs. Ma... more ABSTRACT Introduction To assess an effect of cochleostomy on hearing threshold in guinea pigs. Material and methods The authors performed animal experiments using five 3-month-old guinea pigs. Before experiment hearing threshold were evaluated. Surgery involved access to the temporal bone by a post-auricular incision. After a wide opening of the bulla cochleostomy was created (10 000 turn/min, diamond bur of 0,8 mm diameter). Hearing threshold was identified on the basis of presence of wave V in auditory brainstem responses (ABR) for click and frequency-specific stimulation. Also morphology and latency changes for wave V for this stimulation was assesed. Hearing status was evaluated before, just after and 1-, 2-, and 4-weeks after surgery. For surgical procedure and ABR examination all animals were anesthetized with an intramuscular injection of ketamine (50 mg/kg) mixed with xylazine (9 mg/kg) in the supplemental doses. After surgery the animal was treated by antibioticoterapy for 3 days – Enrofloksacyna 0,3 ml subcutaneouly and analgesic – Tolfedine 0,05 mg in second day. Results Four week observation of ABR morphology and hearing thresholds for click and frequency-specific stimulation of 100 dB SPL intensity showed only temporary changes confirming that cochleostomy did not affect cochlear function. Conclusions The correctly performed cochleostomy in guinea pigs did not affect persistently the cochlear function indicating that such an option of CI electrode insertion in patients is safe.
Evaluation of usefulness new non-contact method--Laser Doppler vibrometry (LDV) in measurements o... more Evaluation of usefulness new non-contact method--Laser Doppler vibrometry (LDV) in measurements of movability of ossicular chain during second look operation was aim of the study. We would like answer to questions: 1. Is LDV helpful in intraoperative conditions? 2. Which measurements points have the largest practical value? 3. Which measured parameters could be used to determination of effectiveness ossicular chain reconstruction? In experiment there were taken 3 fresh temporal bones kept in 0,9% NaCl. In first stage were executed: antromastoidectomy with wide tympanotomy. The ossicular chain movability investigation was conducted on: back branch of stapes, front branch of stapes, round window, umbo of eardrum. Laser Doppler Vibrometer was used to measurement ossicular chain's movability. ER-2 loudspeakers were generated wave: 1000 Hz, 2000 Hz, 4000Hz. In second stage were executed: Malleus-Stapes Assembly (MSA) ossicular chain's reconstruction and repeated investigation in measured points. The most convenient points to measurement were respectively: back branch of stapes, front branch of stapes, umbo of eardrum. In two cases round window was placed in deep niche and was partly covered by facial nerve. MSA performance didn't influence accessibility of measuring points. Theresholds of measured point's movability was useful to evaluation of reconstruction. Back branch of stapes, front branch of stapes and umbo of eardrum are useful to intraoperatve measurements ossicular chain movability. Delimitation thresholds of ossicular chain movability can help in reconstruction's evaluation. After next experiments LDV can be use in practice-intraoperative.
ABSTRACT Introduction The main tumor of cerebellopontine angle are vestibular schwannoma (80–90%)... more ABSTRACT Introduction The main tumor of cerebellopontine angle are vestibular schwannoma (80–90%). According to National Institute of Health Consensus Development Conference the best treatment method is microsurgery. There are three principal surgical approaches: translabyrinthin, retrosigmoid and middle fossa. Only the latter two approaches provide the possibility of hearing preservation. Aim Technique of surgery and postoperative morbidity after MFA. Material and methods 39 patients (40 tumor) suffered from tumor of cerebellopontine angle, operated by using middle fossa approach in years 1998–2007. We evaluate hearing preservation and function of facial nerve and others postoperative morbidity. Results 22.5% of patients has hearing impairment and 32.5% has facial weakness. By individual cases we observed: CSF leak, meningitis, corneal ulceration, ischialgia, wound bleeding and venue thrombosis. 1/3 of patients suffered from headache and disequilibrium and 1/6 suffered from tinnitus. Conclusion According to NIH middle fossa approach is one of three possible approaches in microsurgery of cerebellopontine angle tumors. There is possible total tumor removal with hearing preservation. Monitoring of facial and cochlear nerve during operation is recommended.
Mucocele, though is a common lesion, rarely penetrates to the surrounding intra- and extracranial... more Mucocele, though is a common lesion, rarely penetrates to the surrounding intra- and extracranial spaces. We describe the case of 45-year-old male with 2 years history of a chronic left nasal obstruction and a concentric visual field deficit in the left eye as the only manifestations. Diagnostic CT and MRI imaging revealed a mucocele originating from the posterior ethmoid and sphenoid sinuses and penetrating intracranially to the anterior and middle cranial fossae and extracranially to the pterygopalatine fossa and the parapharyngeal space. This extensive localization appears to be an extremely rare entity, which, to our knowledge, has not been described in the English literature yet. The clinical features and a literature review are also presented.
The most important for the diagnosis of vestibular schwannoma is MRI technic, which allows assess... more The most important for the diagnosis of vestibular schwannoma is MRI technic, which allows assessing its size and shape. The gold diagnostic standard includes also PTA, SD and ABR, nystagmography with calorics and VEMP. Nystagmography with calorics reflects the status of superior vestibular nerve. The sensitivity of calorics amounts to 61–87%. VEMPs reflect the status of interior vestibular nerve; its sensitivity is about 80%. The greatest diagnostic sensitivity shows ABR method, which is estimated for about 96–99%.analysis of PTA, ABR, VEMP and calorics results in smaller G1(≤10 mm) and greater G2 (>11 mm) tumors, and assessement of influence of the size of the tumor for auditory and vestibular function.PTA, ABR, VEMP and calorics results performed in 33 patients with CPA tumors.CPA tumors originate from inferior vestibular nerve in most cases; there is no statistical PTA differences in G1 and G2 groups; sensitivity of calorics (G1 53%, G2 95%), and ABR (G1 75%, G2 100%) depend on tumor size and tumor size has significant influence on results of both of these methods; sensitivity of VEMPs is similar in G1 and G2 groups (83% and 89%).there is no strict correlation between tumor origin and calorics and ABR results; greatest sensitivity in our material show VEMP, what is probably results of frequent tumors origin from inferior vestibular nerve.
The role of medial efferent system in regulating outer hair cell function has been studied by man... more The role of medial efferent system in regulating outer hair cell function has been studied by many investigators. Usually narrow band noise or white noise as contralateral stimulation (CS) suppressors have been used and changes in OAE amplitudes estimated. Thirty children aged 6-15 years (mean 12.5 +/- 4.7), without any changes in tonal and impedance audiometry and with negative history regarding otiatric diseases were examined. Transient evoked otoacoustic emissions (TEOAE) were recorded using ILO 92 Otodynamics Analyser. CS was performed using 1.0 kHz and 2.0 kHz continuous pure tones of 30 dB SL or 50 dB SL. Effects of CS on TEOAE evoked by click of 80, 70 and 60 dB SPL were investigated. TEOAE analysis included assessment of TEOAE amplitude of half octave frequency bandwidth (HOFBW-1.0; HOFBW-1.5; HOFBW-2.0; HOFBW-3.0 and HOFBW-4.0 kHz) and 0.8 kHz frequency bandwidth (0.8-FBW) amplitudes centred at 1.0; 2.0; 3.0; 4.0 and 5.0 kHz. TEOAE amplitude recorded for stimuli 80, 70 and 60 dB SPL without CS decreased: mean values respectively 6.1 +/- 4.2; 5.4 +/- 4.5 and 3.3 dB SPL +/- 4.3. CS effect on TEOAE was observed for all CS options, however, larger suppressive effect was recorded on TEOAE elicited by 70 dB SPL stimulus using 1 kHz/50 dB SL tone as a suppressor and on TEOAE elicited by 60 dB SPL stimulus using 2 kHz/50 dB SL tone as a suppressor. HOFBW and 0.8-FBW analyses showed the association between the frequency/intensity of the suppressors and decreasing of amplitudes of adequate frequency bands. It is concluded that the described method of investigating of the medial olivocochlear efferent system seems to be sensitive and confirms frequency-dependent suppressive effect on OAE.
Round window's movability measurements with helping of LDV in evaluation of ossicular chain funct... more Round window's movability measurements with helping of LDV in evaluation of ossicular chain functioning.Quantitive evaluation of round window movability in normal conditions and after malleus stapes assembly reconstruction were aims of the study.In the experiment there were taken 10 non-frozen temporal bones harvested within 48 hours.Temporal bones specimens were prepared like in closed technique with antromastoidectomy and large posterior tympanotomy. Hearing system before and after MSA reconstruction were evaluated by measurement of round window movement. Measurements were performed at four frequencies: 1000 Hz, 2000 Hz, 4000 Hz, 8000 Hz.In the normal ossicular chain the biggest movability were stated at frequency of 1 kHz. After reconstruction at all frequencies measurements were significantly worse. In reconstructed ears the highest movabilities were stated at frequencies 2000 Hz and 4000 Hz.Round window movability could be measured by Laser Doppler Vibrometry in posterior tympanotomy approach. Before reconstruction the biggest movability were evaluated at 1000 Hz and after MSA at 2000 Hz.
We report 2 cases (52 and 29-year-old men) of CG in the petrous apex we treated in 2004–2006. We ... more We report 2 cases (52 and 29-year-old men) of CG in the petrous apex we treated in 2004–2006. We also review the literature and discus the mechanism of development of CG and the treatment of this lesion.Cholesterol granuloma (CG) is a chronic inflammatory process with associated foreign body reaction to hemorrhage-related cholesterol crystals. Although CG is found in various organs the temporal bone is the most common site of detection. Numerous ethiopathological hypotheses have been proposed but most authorities support the concept of air cell tract blockage in well pneumatized petrous apex. Obstruction of the air cells leads to rupture of blood vessels and hemorrhage. Red blood cell degradation into cholesterol crystals produces a foreign body giant-cell reaction with progressive accumulation of typical brownish glistening fluid. Clinically, this lesion can produce sensorineural hearing loss, tinnitus, hemifacial spasm, facial numbness and trigeminal neuralgia. Cholesteatoma is the main lesion to distinguish from CG. On MRI studies, CG appears with a high signal on both T1- and T2-weighted sequences, cholesteatoma appear bright only on T2-weighted ones. Goal of the surgery is to create a drainage and ventilation of the affected area to prevent recurrence. Several alternative approaches to the petrous apex have been described.12–18 months follow up shows no clinical signs of recurrence.
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