ABSTRACT
BACKGROUND: Air-conducted and skull-tap cervical vestibular evoked myogenic potentials (AC-cVEMP and Tap-cVEMP) have been shown to be very promising tools in clinical practice. They are noninvasive, easy to obtain and - importantly - they require little time and the cost of the instruments is low. OBJECTIVES: The aim of this study was to evaluate the usefulness of the combined use of ACand Tap-cVEMPs as a diagnostic tool for advanced assessment of vestibular schwannoma in determining tumor origin, and to investigate whether the results are helpful for a surgeon as an additional source of information about the tumor before surgery. MATERIAL AND METHODS: ACand Tap-cVEMPs were acquired (with EMG-based biofeedback) from the sternocleidomastoid muscles (SCM) of 30 vestibular schwannoma patients just before surgery. The results were compared to the surgical information about nerve bundle involvement in the tumor and the size of the tumor obtained from magnetic resonance imaging (MRI). RESULTS: On the tumor side, abnormal corrected amplitude asymmetry ratios were detected in 73.33% of the patients, abnormalities in P1-latencies in 70% of the patients, and both in 90% of the patients. The cervical vestibular evoked myogenic potential (cVEMP) results indicated the affected nerve division to be the inferior in 23.33% of the patients, the superior in 20% of the patients, and both in 46.67% of the patients. No cVEMP abnormalities were found in 10% of cases. The combined results of both ACand Tap-cVEMP were significantly compatible with the surgical information about the tumor origin. The number of abnormalities was significantly correlated with the tumor size. CONCLUSIONS: The information provided by the combined application of ACand Tap-cVEMPs might be useful for a surgeon in presurgical planning, providing more detailed information about the tumor and the affected nerve division in the internal auditory canal. It is not a diagnostic replacement for MRI in vestibular schwannoma patients; however, in our opinion, ACand Tap-cVEMPs may serve as additional sources of information about the tumor before the surgery.
Subject(s)
Neck Muscles , Neuroma, Acoustic/diagnosis , Vestibular Evoked Myogenic Potentials/physiology , Acoustic Stimulation , Audiometry, Pure-Tone , Humans , Magnetic Resonance Imaging , Neuroma, Acoustic/pathology , Neuroma, Acoustic/physiopathology , SkullABSTRACT
Wstep: Cel badania stanowi ocena efektów dlugoterminowych augmentacji krtani w znieczuleniu miejscowym przy pomocy hydroksyapatytu wapnia. Material i metody: W badaniu wzielo udzial 17 pacjentów, którzy z powodu niewydolnosci szpary glosni (z powodu jednostronnego porazenia krtani oraz niewydolnosci miesni wewnetrznych krtani) zostali zakwalifikowani do przeprowadzenia augmentacji krtani (10 kobiet i 17 mezczyzn), w wieku: 57,6±17,7 lat, mediana 61 lat, z zakresem: 32-83 lata. U wszystkich pacjentów wykonano augmentacje krtani w znieczuleniu miejscowym, przez jame ustna, podajac bocznie od faldu glosowego/ faldów glosowych hydroksyapatyt wapnia (preparat Radiesse). W celu oceny efektów dlugoterminowych augmentacji krtani - przeprowadzano ocene jakosci glosu pacjenta przed augmentacja, a nastepnie 3 i 12 miesiecy po augmentacji krtani, przy pomocy oceny videolaryngostroboskopowej krtani, oceny odsluchowej, analizy akustycznej, oceny aerodynamicznej oraz samooceny glosu dokonanej przez pacjenta przy pomocy kwestionariusza VRQoL. Wyniki: Uzyskano istotna statystycznie poprawe w ocenie odsluchowej glosu dla parametrów G i A, po 3 miesiacach, dobre wyniki utrzymywaly sie w czasie 12-miesiecznej obserwacji. W ocenie akustycznej MDVP_Jitt, MDVP_Shim i MDVP_NHR poprawily sie odpowiednio do wartosci: 2,5; 5 oraz 0,1 (3 miesiace po augmentacji) i 1,9; 3,6 oraz 0,1 (12 miesiace po augmentacji). MPTa wydluzyl sie do 12,2 i 11,9 s., odpowiednio po 3 i 12 miesiacach od augmentacji. Natezenie glosu poprawilo sie z 67 do 68 oraz 71 dB(A), odpowiednio po 3 i 12 miesiacach. Wyniki: VRQoL poprawily sie do wartosci 19,5 i 20, odpowiednio 3 i 12 miesiecy po augmentacji. Dyskusja Augmentacja krtani w znieczuleniu miejscowym przy pomocy hydroksyapatytu wapnia daje dlugotrwale, dobre efekty leczenia.
Subject(s)
Anesthesia, Local/methods , Biocompatible Materials/therapeutic use , Durapatite/therapeutic use , Laryngeal Diseases/therapy , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Treatment OutcomeABSTRACT
OBJECTIVES: To evaluate the accuracy with which the innovative QASSR method predicts behavioral thresholds in adult patients with sensorineural hearing loss. DESIGN: Subjects were tested at four carrier frequencies (500, 1000, 2000, and 4000 Hz).The resulting QASSR recordings were analyzed for thresholds and magnitude/phase characteristics. Tone-burst ABR was recovered from QASSR signal using CLAD method and analyzed in the time domain. The electrophysiological estimates were compared to hearing thresholds determined behaviorally. STUDY SAMPLE: Sixteen ears of nine volunteer subjects recruited from a clinical population. RESULTS: All mean threshold estimates differed less than 3 dB for QASSR and less than 5 dB for ABR at 1000, 2000 and 4000Hz (carrier or pure-tone test frequencies). The largest differences were observed for both at 500 Hz (5.63 and 11.56 dB respectively).The audiometric configurations of QASSR and ABR estimates followed those of the respective behaviorally determined configurations across ears tested. CONCLUSIONS: QASSR method merges two dissimilar stimulation techniques, transient and steady-state, to create a hybrid stimulation-and-analysis paradigm that seems to improve the overall performance of the electrophysiological threshold estimation. The unique feature of the QASSR technique is the additional information afforded by the transient ABR, recovered from the same recording. The QASSR thus holds promise to be a very useful tool for practical clinical applications.
Subject(s)
Audiometry, Evoked Response/methods , Audiometry, Pure-Tone/methods , Auditory Threshold/physiology , Evoked Potentials, Auditory, Brain Stem/physiology , Hearing Loss, Sensorineural/physiopathology , Acoustic Stimulation/methods , Adult , Aged , Female , Hearing Loss, Sensorineural/psychology , Humans , Male , Middle Aged , Predictive Value of TestsABSTRACT
Efficacy of the SPEAK and ACE coding strategies was compared with that of a new strategy, MP3000™, by 37 European implant centers including 221 subjects. The SPEAK and ACE strategies are based on selection of 8-10 spectral components with the highest levels, while MP3000 is based on the selection of only 4-6 components, with the highest levels relative to an estimate of the spread of masking. The pulse rate per component was fixed. No significant difference was found for the speech scores and for coding preference between the SPEAK/ACE and MP3000 strategies. Battery life was 24% longer for the MP3000 strategy. With MP3000 the best results were found for a selection of six components. In addition, the best results were found for a masking function with a low-frequency slope of 50 dB/Bark and a high-frequency slope of 37 dB/Bark (50/37) as compared to the other combinations examined of 40/30 and 20/15 dB/Bark. The best results found for the steepest slopes do not seem to agree with current estimates of the spread of masking in electrical stimulation. Future research might reveal if performance with respect to SPEAK/ACE can be enhanced by increasing the number of channels in MP3000 beyond 4-6 and it should shed more light on the optimum steepness of the slopes of the masking functions applied in MP3000.
Subject(s)
Cochlear Implants , Signal Processing, Computer-Assisted , Acoustic Stimulation/instrumentation , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cochlear Implantation/instrumentation , Electronics , Equipment Design , Female , Humans , Male , Middle Aged , Perceptual Masking , Psychophysics , Signal Processing, Computer-Assisted/instrumentation , Spectrum Analysis , Speech Acoustics , Telemetry/methods , Young AdultABSTRACT
INTRODUCTION: An assumption was taken that in central nervous system (CNS) in patients above 15 years of age there are possible mechanisms of neuronal changes. Those changes allow for reconstruction or formation of natural activation pattern of appropriate brain structures responsible for auditory speech processing. AIM: The aim of the study was to observe if there are any dynamic functional changes in central nervous system and their correlation to the auditory-verbal skills of the patients. MATERIAL AND METHODS: Nine right-handed patients between 15 and 36 years of age were examined, 6 females and 3 males. All of them were treated with cochlear implantation and are in frequent follow-up in the Department of Otolaryngology at the Medical University of Warsaw due to profound sensorineural hearing loss. In present study the patients were examined within 24 hours after the first fitting of the speech processor of the cochlear implant, and 1 and 2 years subsequently. Combination of performed examinations consisted of: positone emission tomography of the brain, and audiological tests including speech assessment. In the group of patients 4 were postlingually deaf, and 5 were prelinqually deaf. RESULTS: Postlingually deaf patients achieved great improvement of hearing and speech understanding. In their first PET examination very intensive activation of visual cortex V1 and V2 (BA17 and 18) was observed. There was no significant activation in the dominant (left) hemisphere of the brain. In PET examination performed 1 and 2 years after the cochlear implantation no more V1 and V2 activation region was observed. Instead particular regions of the left hemisphere got activated. In prelingually deaf patients no significant changes in central nervous system were noticeable neither in PET nor in speech assessment, although their hearing possibilities improved. CONCLUSIONS: Positive correlation was observed between the level of speech understanding, linguistic skills and the activation of appropriate areas of the left hemisphere of the brain in postlingually deaf patients treated with cochlear implants. No such correlation was noted in prelingualy patients treated with the same method.
Subject(s)
Auditory Cortex/diagnostic imaging , Auditory Perception/physiology , Cochlear Implantation , Deafness/rehabilitation , Evoked Potentials, Auditory, Brain Stem/physiology , Speech Perception/physiology , Acoustic Stimulation , Adolescent , Adult , Auditory Cortex/blood supply , Deafness/surgery , Female , Follow-Up Studies , Humans , Male , Poland , Recovery of Function , Tomography, Emission-Computed/methods , Young AdultABSTRACT
UNLABELLED: Round window's movability measurements with helping of LDV in evaluation of ossicular chain functioning. AIM OF STUDY: Quantitive evaluation of round window movability in normal conditions and after malleus stapes assembly reconstruction were aims of the study. METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSIONS: 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
Subject(s)
Ear Ossicles/physiology , Ear Ossicles/surgery , Laser-Doppler Flowmetry/methods , Monitoring, Intraoperative/methods , Temporal Bone/surgery , Tympanoplasty/methods , Acoustic Stimulation , Aged , Aged, 80 and over , Ear Cartilage/physiology , Ear Cartilage/surgery , Female , Humans , Male , Middle Aged , Poland , Stapes SurgeryABSTRACT
AIM OF STUDY: 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? METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSIONS: 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.
Subject(s)
Acoustic Stimulation , Ear Cartilage/surgery , Ear Ossicles/physiology , Ear Ossicles/surgery , Monitoring, Intraoperative/methods , Temporal Bone/surgery , Vibration , Cadaver , Ear Cartilage/physiology , Humans , Laser-Doppler Flowmetry , Models, Biological , Otologic Surgical Procedures , Stapes SurgeryABSTRACT
OBJECTIVE: To investigate the use of transtympanic electrocochleography (TT-ECochG) analyzed on-line by a detector strategy software that made possible automatic extraction of TT-ECochG components intraoperatively in real-time domain. PATIENTS: Fifteen patients with cerebellopontine angle tumor among 50 patients were included in this study. INTERVENTION: All subjects were operated on via middle fossa or retrosigmoid approach. Pure-tone average (PTA) was measured at 0.5, 1.0, and 2.0 kHz, and calculations were performed before and after surgery. Auditory function was monitored intraoperatively via TT-ECochG, and analyzed data were displayed on-line. MAIN OUTCOME MEASURES: TT-ECochG changes in morphology were described. Postoperative PTA elevation level correlated with TT-ECochG morphology changes occurring intraoperatively. RESULTS: Analyzed on-line, TT-ECochG data were displayed as first negative peak of compound action potential amplitude and latency in time domain every 3 to 5 seconds. A good correlation between postoperative PTA elevation and TT-ECochG morphology changes was showed (Spearman rank test, R = +0.93; t(N-2) = 9.00; p < 0.0001). CONCLUSION: TT-EcochG seemed to effectively mirror even minimal changes in auditory function during intraoperative monitoring in real-time domain. Developed strategy of on-line analysis makes the intraoperative hearing status assessment faster and easier.