1
|
Guzzi G, Ricciuti RA, Della Torre A, Lo Turco E, Lavano A, Longhini F, La Torre D. Intraoperative Neurophysiological Monitoring in Neurosurgery. J Clin Med 2024; 13:2966. [PMID: 38792507 PMCID: PMC11122101 DOI: 10.3390/jcm13102966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/08/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024] Open
Abstract
Intraoperative neurophysiological monitoring (IONM) is a crucial advancement in neurosurgery, enhancing procedural safety and precision. This technique involves continuous real-time assessment of neurophysiological signals, aiding surgeons in timely interventions to protect neural structures. In addition to inherent limitations, IONM necessitates a detailed anesthetic plan for accurate signal recording. Given the growing importance of IONM in neurosurgery, we conducted a narrative review including the most relevant studies about the modalities and their application in different fields of neurosurgery. In particular, this review provides insights for all physicians and healthcare professionals unfamiliar with IONM, elucidating commonly used techniques in neurosurgery. In particular, it discusses the roles of IONM in various neurosurgical settings such as tumoral brain resection, neurovascular surgery, epilepsy surgery, spinal surgery, and peripheral nerve surgery. Furthermore, it offers an overview of the anesthesiologic strategies and limitations of techniques essential for the effective implementation of IONM.
Collapse
Affiliation(s)
- Giusy Guzzi
- Neurosurgery Department, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
| | | | - Attilio Della Torre
- Neurosurgery Department, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
| | - Erica Lo Turco
- Neurosurgery Department, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
| | - Angelo Lavano
- Neurosurgery Department, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
| | - Federico Longhini
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
- Anesthesia and Intensive Care Unit, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
| | - Domenico La Torre
- Neurosurgery Department, “R. Dulbecco” Hospital, 88100 Catanzaro, Italy
- Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy
| |
Collapse
|
2
|
Electrophysiological predictors of hearing deterioration based on AEP monitoring during petroclival meningioma resection. Neurosurg Rev 2020; 44:1601-1609. [PMID: 32671694 DOI: 10.1007/s10143-020-01350-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/09/2020] [Accepted: 07/08/2020] [Indexed: 10/23/2022]
Abstract
The objective of this study was to calculate the risk of postsurgical hearing deterioration as a function of changes in the amplitude and latency of the most stable components (waves III and V) of the auditory evoked potential (AEP) during petroclival meningioma resection surgery. We retrospectively analyzed intraoperative AEP monitoring results and pre- and postsurgical hearing status in 40 consecutive patients who were surgically treated for petroclival meningiomas. Statistical analyses were conducted to identify the most sensitive and specific way to predict hearing dysfunction after surgery. Patients' mean age was 59 ± 10 years, and 31 (77.5%) were women. Twelve (30%) patients presented with clinically detectable hearing impairment preoperatively. At the first postoperative assessment, four of those 12 patients reported subjective improvement, and eight reported hearing deterioration. Of those eight, four remained stable and four recovered hearing by the last assessment. Wave III latency reached its highest specificity (100%) and sensitivity (71.43%) at x = 143%. Wave V latency, on the other hand, reached its highest sensitivity (71%) and specificity (93%) at x = 124%. Finally, wave V amplitude reached its highest sensitivity (100%) and specificity (79%) at x = 74%. Intraoperative alterations of wave III latency and wave V amplitude seem to be highly sensitive and specific at predicting the risk of auditory dysfunction in patients undergoing petroclival meningioma resection and should be used to determine maximum resection with preservation of function.
Collapse
|
3
|
Kasbekar AV, Tam YC, Carlyon RP, Deeks JM, Donnelly N, Tysome J, Mannion R, Axon PR. Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a "Test Intracochlear Electrode". J Neurol Surg Rep 2019; 80:e1-e9. [PMID: 30723658 PMCID: PMC6361632 DOI: 10.1055/s-0038-1673649] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 07/27/2017] [Indexed: 10/31/2022] Open
Abstract
Objectives A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting This study was set at a tertiary referral center for skull base pathology. Main outcome measure Preserved auditory brainstem responses leading to cochlear implantation. Results Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf.
Collapse
Affiliation(s)
- Anand V Kasbekar
- Cambridge Skull Base Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.,Department of Otorhinolaryngology, Head and Neck Surgery, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom.,NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom
| | - Yu Chuen Tam
- Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Robert P Carlyon
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, United Kingdom
| | - John M Deeks
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, United Kingdom
| | - Neil Donnelly
- Cambridge Skull Base Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - James Tysome
- Cambridge Skull Base Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Richard Mannion
- Cambridge Skull Base Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Patrick R Axon
- Cambridge Skull Base Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| |
Collapse
|
4
|
El Damaty A, Rosenstengel C, Matthes M, Baldauf J, Dziemba O, Hosemann W, Schroeder HWS. A New Score to Predict the Risk of Hearing Impairment After Microvascular Decompression for Hemifacial Spasm. Neurosurgery 2018; 81:834-843. [PMID: 28973677 DOI: 10.1093/neuros/nyx111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/28/2017] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) has been implemented to reduce the risk of hearing impairment during microvascular decompression for hemifacial spasm. OBJECTIVE To evaluate intraoperative monitoring of BAEPs during microvascular decompression in patients with hemifacial spasm for predicting the risk of hearing impairment after surgery. METHODS This prospective study included 100 patients. BAEPs were recorded for all patients. We established a scoring system for the changes in wave I amplitude, I-III interpeak latency, and wave V amplitude and latency. For each change, total points were calculated, and a score out of 6 was assigned to every patient. We classified the patients based on the points scored into 3 risk groups: low-risk (0-3), medium-risk (4-5), and high-risk (6). Further, the correlation between the score and the hearing outcome was evaluated to detect the incidence and degree of hearing impairment. RESULTS Eighty-seven patients scored 0 to 3, 10 scored 4 to 5, and 3 scored 6. The degree of hearing impairment was proportionate to the score recorded at the end of surgery, and patients in the low-risk group showed no impairment; medium-risk group, deterioration of maximum 2 grades according to World Health Organization classification of hearing impairment; and high-risk group, deterioration of 3 to 4 grades. CONCLUSION Intraoperative monitoring of BAEPs evaluated through our scoring system was valuable in predicting hearing impairment after surgery.
Collapse
Affiliation(s)
- Ahmed El Damaty
- Department of Neurosurgery, Cairo University, Cairo, Egypt.,Department of Neurosurgery, Greifswald University Medicine, Greifswald, Germany
| | | | - Marc Matthes
- Department of Neurosurgery, Greifswald University Medicine, Greifswald, Germany
| | - Joerg Baldauf
- Department of Neurosurgery, Greifswald University Medicine, Greifswald, Germany
| | - Oliver Dziemba
- Department of ENT, Head and Neck Surgery, Greifswald University of Medicine, Greifswald, Germany
| | - Werner Hosemann
- Department of ENT, Head and Neck Surgery, Greifswald University of Medicine, Greifswald, Germany
| | - Henry W S Schroeder
- Department of Neurosurgery, Greifswald University Medicine, Greifswald, Germany
| |
Collapse
|
5
|
Sindou M, Mercier P. Microvascular decompression for hemifacial spasm : Surgical techniques and intraoperative monitoring. Neurochirurgie 2018; 64:133-143. [DOI: 10.1016/j.neuchi.2018.04.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/22/2018] [Accepted: 04/06/2018] [Indexed: 11/30/2022]
|
6
|
Rampp S, Rensch L, Simmermacher S, Rahne T, Strauss C, Prell J. Intraoperative auditory steady-state monitoring during surgery in the cerebellopontine angle for estimation of postoperative hearing classes. J Neurosurg 2016; 127:559-568. [PMID: 27739939 DOI: 10.3171/2016.7.jns16460] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Brainstem auditory evoked potentials (BAEPs) have been used for intraoperative monitoring of the auditory nerve for many years. However, BAEPs yield limited information about the expected postoperative hearing quality and speech perception. The auditory steady-state response (ASSR) enables objective audiograms to be obtained in patients under anesthesia. These ASSRs could be used for intraoperative estimation of hearing classes to improve the postoperative outcome and quality of life. Studies investigating the clinical use of ASSRs during total intravenous anesthesia are currently lacking. The work presented in this article therefore investigates the application of ASSRs for intraoperative estimation of hearing classes. METHODS In 43 patients undergoing surgery for vestibular schwannoma, ASSR measurements were performed at the beginning and end of the surgical procedure. ASSR stimuli consisted of 80-dB hearing level amplitude-modulated tones with 5-minute duration, 90-Hz modulation, and 3 different carrier frequencies: 500, 1000, and 2000 Hz. Stimulation was performed unilaterally with and without contralateral masking, using single and combined carriers. Evoked responses were recorded and analyzed in the frequency domain. ASSRs were compared with extraoperative hearing classes and BAEPs using ANOVA, correlation, and receiver operating characteristic statistics. RESULTS ASSRs yielded high and consistent area under the curve (AUC) values (mean 0.83) and correlation values (mean -0.63), indicating reliable prediction of hearing classes. Analysis of BAEP amplitude changes showed lower AUC (mean 0.79) and correlation values (0.63, 0.37, and 0.50 for Waves I, III, and V, respectively). Latencies showed low AUC values (mean 0.6) and no significant correlation. Combination of several carriers for simultaneous evaluation reduced ASSR amplitudes and respective AUC values. Contralateral masking did not show a significant effect. CONCLUSIONS ASSRs robustly estimate hearing class in patients under total intravenous anesthesia, even when using short measurement durations. The method provides a diagnostic performance that exceeds conventional BAEP monitoring and enables objective and automated evaluation. On the basis of these findings, continuous intraoperative auditory monitoring could become a promising alternative or adjunct to BAEPs.
Collapse
Affiliation(s)
| | | | | | - Torsten Rahne
- Otorhinolaryngology, Head and Neck Surgery, University Hospital Halle (Saale), Germany
| | | | | |
Collapse
|
7
|
Postoperative complications of microvascular decompression for hemifacial spasm: lessons from experience of 2040 cases. Neurosurg Rev 2015; 39:151-8; discussion 158. [DOI: 10.1007/s10143-015-0666-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 04/11/2015] [Accepted: 04/27/2015] [Indexed: 11/29/2022]
|
8
|
Lee MH, Lee HS, Jee TK, Jo KI, Kong DS, Lee JA, Park K. Cerebellar retraction and hearing loss after microvascular decompression for hemifacial spasm. Acta Neurochir (Wien) 2015; 157:337-43. [PMID: 25514867 DOI: 10.1007/s00701-014-2301-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 12/01/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND This retrospective study evaluated the length of cerebellar retraction and the changes of intraoperative brainstem auditory evoked potential (BAEP) during microvascular decompression (MVD), and assessed the predictive value of the hearing loss as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS). METHODS This series included 1,518 consecutive patients affected with HFS who underwent MVD, during which BAEP was monitored. Patients were divided into two groups based on whether hearing loss occurred following decompression or not. Each patient underwent a similar procedure performed by one neurosurgeon. The two patients groups were matched with regard to sex, age, and degree of spasm. RESULTS Among the 1,518 patients, 106 (6.98 %) displayed functional hearing changes. Hearing loss was permanent in 12 patients (0.79 %). Of the 1,412 patients with stationary hearing compared with preoperative audiometry, 96 patients were selected who were individually matched with respect to sex, age, and degree of spasm. BAEP changed immediately after cerebellar retraction in 7 of 12 hearing-loss patients, suggesting the importance of retraction on hearing outcomes. The distance from the cerebellar surface of the petrous temporal bone to the neurovascular compression point was measured. The median distance of cerebellar retraction in the hearing-loss group was 13.77 mm, which was longer than the median distance in the control group. CONCLUSIONS Preoperative measurement of the cerebellar retraction distance can be a valuable clue to predict and prevent postoperative hearing loss in MVD for HFS.
Collapse
|
9
|
Krieg SM, Kempf L, Droese D, Rosahl SK, Meyer B, Lehmberg J. Superiority of tympanic ball electrodes over mastoid needle electrodes for intraoperative monitoring of hearing function. J Neurosurg 2014; 120:1042-7. [DOI: 10.3171/2014.1.jns13396] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Recording the auditory brainstem response (ABR) is a common method for monitoring the integrity of auditory pathways during surgery in the cerebellopontine angle. Electrocochleography (ECochG) is an alternative means of intraoperative neuromonitoring. In the present study the authors compared the practicability and prognostic significance of these two methods by performing simultaneous recordings in the operating room.
Methods
Between 2006 and 2011, 125 patients (mean age 55 years) underwent surgery in the cerebellopontine angle. Seventy-one percent of the patients presented with a hearing deficit, and 37% had useful hearing but with slight functional impairment. Auditory brainstem response was recorded with a subdermal needle electrode at the mastoid. For ECochG recording, a noninvasive ball electrode was attached to the tympanic membrane. Amplitudes obtained from both ECochG and ABR audiometry were compared and correlated to pre- and postoperative hearing deficits.
Results
Simultaneous intraoperative monitoring via ABR and ECochG was possible in 114 cases (91%). Postoperatively, 42% of patients showed some degree of new hearing deficit, whereas 4% had improvement. The mean amplitudes in ECochG monitoring were significantly higher (0.18 ± 0.04 μV) than the ABR potentials (0.08 ± 0.006 μV; p < 0.05). All waves recorded at the mastoid needle electrode could be recognized in the potentials of the tympanic ball electrode. Hearing outcome correlated more reliably with the relative amplitude changes in Waves III and V in ECochG (III: p = 0.0008, V: p = 0.0015) than in ABR monitoring (III: p = 0.2075, V: p = 0.0398).
Conclusions
Intraoperative monitoring of the auditory system by recording with noninvasive tympanic ball electrodes is more practicable than with subcutaneous needle electrodes at the tragus. Since there is also a reliable correlation between ECochG and clinical outcome, the method can replace common ABR recording during surgery in the cerebellopontine angle.
Collapse
Affiliation(s)
| | | | - Doris Droese
- 2Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich; and
| | | | | | | |
Collapse
|
10
|
Kim SM, Kim SH, Seo DW, Lee KW. Intraoperative neurophysiologic monitoring: basic principles and recent update. J Korean Med Sci 2013; 28:1261-9. [PMID: 24015028 PMCID: PMC3763097 DOI: 10.3346/jkms.2013.28.9.1261] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/18/2013] [Indexed: 11/23/2022] Open
Abstract
The recent developments of new devices and advances in anesthesiology have greatly improved the utility and accuracy of intraoperative neurophysiological monitoring (IOM). Herein, we review the basic principles of the electrophysiological methods employed under IOM in the operating room. These include motor evoked potentials, somatosensory evoked potentials, electroencephalography, electromyography, brainstem auditory evoked potentials, and visual evoked potentials. Most of these techniques have certain limitations and their utility is still being debated. In this review, we also discuss the optimal stimulation/recording method for each of these modalities during individual surgeries as well as the diverse criteria for alarm signs.
Collapse
Affiliation(s)
- Sung-Min Kim
- Department of Neurology, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, Korea
| | - Dae-Won Seo
- Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kwang-Woo Lee
- Department of Neurology, Seoul National University College of Medicine, Seoul, Korea
| |
Collapse
|
11
|
Oh T, Nagasawa DT, Fong BM, Trang A, Gopen Q, Parsa AT, Yang I. Intraoperative neuromonitoring techniques in the surgical management of acoustic neuromas. Neurosurg Focus 2013; 33:E6. [PMID: 22937857 DOI: 10.3171/2012.6.focus12194] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Unfavorable outcomes such as facial paralysis and deafness were once unfortunate probable complications following resection of acoustic neuromas. However, the implementation of intraoperative neuromonitoring during acoustic neuroma surgery has demonstrated placing more emphasis on quality of life and preserving neurological function. A modern review demonstrates a great degree of recent success in this regard. In facial nerve monitoring, the use of modern electromyography along with improvements in microneurosurgery has significantly improved preservation. Recent studies have evaluated the use of video monitoring as an adjunctive tool to further improve outcomes for patients undergoing surgery. Vestibulocochlear nerve monitoring has also been extensively studied, with the most popular techniques including brainstem auditory evoked potential monitoring, electrocochleography, and direct compound nerve action potential monitoring. Among them, direct recording remains the most promising and preferred monitoring method for functional acoustic preservation. However, when compared with postoperative facial nerve function, the hearing preservation is only maintained at a lower rate. Here, the authors analyze the major intraoperative neuromonitoring techniques available for acoustic neuroma resection.
Collapse
Affiliation(s)
- Taemin Oh
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, CA 90095-1761, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Neurophysiologic Intraoperative Monitoring of the Vestibulocochlear Nerve. J Clin Neurophysiol 2011; 28:566-81. [DOI: 10.1097/wnp.0b013e31823da494] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
13
|
Kartush JM, Larouere MJ, Graham MD, Bouchard KR, Audet BV. Intraoperative cranial nerve monitoring during posterior skull base surgery. Skull Base 2011; 1:85-92. [PMID: 17170827 PMCID: PMC1656318 DOI: 10.1055/s-2008-1056986] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Intraoperative monitoring of neurophysiologic function is rapidly evolving as an important adjunct during skull base surgery to reduce the incidence of neurologic deficit. Facial nerve monitoring is an excellent model, since electrical and mechanical evoked potentials can be directly presented to the surgeon in real-time through an acoustic loudspeaker display. The lower cranial nerves may also be monitored using similar electromyographic techniques. Auditory system monitoring is more difficult due to the low amplitude response that requires averaging and filtering to extract the evoked potential. In conjunction with auditory monitoring, improved hearing preservation may be further enhanced by concomitant facial nerve monitoring, since the surgeon is alerted to traumatic manipulations that may affect both facial and cochlear nerves. Techniques and interpretative issues are presented to maximize the efficacy and safety of cranial nerve monitoring.
Collapse
|
14
|
Selesnick SH, Goldsmith DF. Issues in the optimal selection of a cranial nerve monitoring system. Skull Base Surg 2011; 3:230-9. [PMID: 17170916 PMCID: PMC1656448 DOI: 10.1055/s-2008-1060588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Intraoperative nerve monitoring (IONM) is a safe technique that is of clear clinical value in the preservation of cranial nerves in skull base surgery and is rapidly becoming the standard of care. Available nerve monitoring systems vary widely in capabilities and costs. A well-informed surgeon may best decide on monitoring needs based on surgical case selection, experience, operating room space, availability of monitoring personnel, and cost. Key system characteristics that should be reviewed in the decision-making process include the monitoring technique (electromyography, pressure transducer, direct nerve monitoring, brainstem auditory evoked potential) and the stimulus technique (stimulating parameters, probe selection). In the past, IONM has been primarily employed in posterior fossa and temporal bone surgery, but the value of IONM is being recognized in more skull base and head and neck surgeries. Suggested IONM strategies for specific surgeries are presented.
Collapse
|
15
|
Wilkins RH, Radtke RA, Erwin CW. Value of intraoperative brainstem auditory evoked potential monitoring in reducing the auditory morbidity associated with microvascular decompression of cranial nerves. Skull Base Surg 2011; 1:106-9. [PMID: 17170830 PMCID: PMC1656316 DOI: 10.1055/s-2008-1056989] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The present study was performed to determine whether the intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) during microvascular decompression operations is effective in preventing profound hearing loss or deafness in the ipsilateral ear. The authors retrospectively compared the auditory morbidity of posterior fossa microvascular decompression surgery for the treatment of tic douloureux and hemifacial spasm before and after the introduction of routine intraoperative BAEP monitoring in 1984. Each patient underwent a similar procedure performed by the same surgeon. The two patient groups were comparable with regard to age, sex, and indications for surgery, Auditory morbidity did not decline with the increasing experience of the surgeon prior to 1984; 10 (6.6%) of 152 primary operations (151 patients) in which monitoring was not performed were followed by a profound ipsilateral hearing loss or deafness. In the monitored group, none of 109 operations (104 patients) caused profound hearing loss or deafness. This significant decline in auditory morbidity is attributed by the authors to the use of intraoperative BAEP monitoring, which allows the surgeon to alter the operation in response to degradations in the wave patterns. Based on our experience and that of others, we believe that intraoperative BAEP monitoring is of value in reducing the auditory morbidity of posterior fossa microvascular decompression surgery.
Collapse
|
16
|
Intraoperative brainstem auditory evoked potential observations after trigeminocardiac reflex during cerebellopontine angle surgery. J Neurosurg Anesthesiol 2011; 22:347-53. [PMID: 20706143 DOI: 10.1097/ana.0b013e3181eac551] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The occurrence of trigeminocardiac reflex (TCR) is known to be a negative prognostic factor for hearing preservation in cerebellopontine angle tumor surgery. Our study was conducted to investigate brainstem auditory evoked potential (BAEP) changes after this reflex in cerebellopontine angle tumor surgery and to evaluate their impact on postoperative hearing function. METHODS Five of 102 consecutive patients had an intraoperative TCR (4.9%) and were retrospectively evaluated for the intraoperative BAEP changes after TCR and postoperative auditory function (7 to 10 d after surgery). One of the 5 patients was preoperatively deaf and therefore excluded from this analysis. RESULTS Four patients with preoperative functional hearing developed one or more episodes of TCR. Intraoperative BAEP was maintained in 1 patient, whereas in 3 cases an acute intraoperative BAEP deterioration occurred within 2:04 to 3:27 minutes (mean 2:44 min) after TCR with increased wave latency, decreased wave amplitude, and even wave loss. Two patients had deteriorated BAEP waves until the surgical completion and were postoperatively deaf. CONCLUSIONS Although no direct cause-effect relationship has yet been shown, we suggest TCR as an additional event that may cause BAEP changes. The observed BAEP alterations occurred minutes rather than seconds after the TCR incident leading to both temporary and permanent wave deterioration. This association of BAEP deterioration and TCR occurrence, however, remains yet to be proven justifying further study in the field.
Collapse
|
17
|
Lee SH, Song DG, Kim S, Lee JH, Kang DG. Results of auditory brainstem response monitoring of microvascular decompression: A prospective study of 22 patients with hemifacial spasm. Laryngoscope 2009; 119:1887-92. [DOI: 10.1002/lary.20605] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Polo G, Fischer C. Monitorage peropératoire des potentiels évoqués auditifs précoces dans la chirurgie de décompression microchirurgicale des nerfs crâniens de l’angle pontocérébelleux. Neurochirurgie 2009; 55:152-7. [DOI: 10.1016/j.neuchi.2009.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 10/21/2022]
|
19
|
Dannenbaum M, Lega BC, Suki D, Harper RL, Yoshor D. Microvascular decompression for hemifacial spasm: long-term results from 114 operations performed without neurophysiological monitoring. J Neurosurg 2008; 109:410-5. [DOI: 10.3171/jns/2008/109/9/0410] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Microvascular decompression (MVD) of the facial nerve is an effective treatment for hemifacial spasm (HFS), but the procedure is associated with a significant risk of complications such as hearing loss and facial weakness. Many surgeons advocate the use of intraoperative brainstem auditory evoked response (BAER) monitoring in an attempt to improve surgical outcomes. The authors critically assessed a large series of patients with HFS who underwent MVD without neurophysiological monitoring.
Methods
The authors retrospectively identified 114 consecutive patients, with a history of HFS and without a history of HFS surgery, in whom MVD was performed by a single surgeon without the use of neurophysiological monitoring. Postoperative outcomes were determined by reviewing records and through telephone interviews. At least 1 year of postoperative follow-up data were available for 91 of the 114 patients, and the median follow-up duration in all cases was 8 years (range 3 months–23 years). A Kaplan–Meier analysis showed that 86% of the patients were spasm free at 10 years postoperatively.
Results
There were no surgical deaths or major deficits, and complications included 1 case of postoperative deafness, 1 of permanent subtotal hearing loss, and 10 of delayed facial palsy, 2 of which did not completely resolve at last follow-up. The outcomes, rates of hearing loss, and other complications compared well with those reported in studies in which investigators used intraoperative monitoring.
Conclusions
The results suggest that MVD without neurophysiological monitoring is a safe and effective treatment option in patients with HFS. Although BAER monitoring may be a valuable adjunct to surgery at centers experienced with the modality, the absence of intraoperative monitoring should not prevent neurosurgeons from performing MVD in patients with HFS.
Collapse
Affiliation(s)
| | - Bradley C. Lega
- 3Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania and
| | - Dima Suki
- 4Department of Neurosurgery, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Richard L. Harper
- 1Department of Neurosurgery, Baylor College of Medicine
- 2Department of Neurosurgery, The Methodist Hospital, Houston, Texas
| | - Daniel Yoshor
- 1Department of Neurosurgery, Baylor College of Medicine
- 2Department of Neurosurgery, The Methodist Hospital, Houston, Texas
| |
Collapse
|
20
|
Yingling CD, Gardi JN. Intraoperative Monitoring of Facial and Cochlear Nerves During Acoustic Neuroma Surgery. Neurosurg Clin N Am 2008; 19:289-315, vii. [DOI: 10.1016/j.nec.2008.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
21
|
Kong DS, Park K. Hemifacial spasm: a neurosurgical perspective. J Korean Neurosurg Soc 2007; 42:355-62. [PMID: 19096569 DOI: 10.3340/jkns.2007.42.5.355] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 09/19/2007] [Indexed: 11/27/2022] Open
Abstract
Hemifacial spasm (HFS) is characterized by tonic clonic contractions of the muscles innervated by the ipsilateral facial nerve. Compression of the facial nerve by an ectatic vessel is widely recognized as the most common underlying etiology. HFS needs to be differentiated from other causes of facial spasms, such as facial tic, ocular myokymia, and blepharospasm. To understand the overall craniofacial abnormalities and to perform the optimal surgical procedures for HFS, we are to review the prevalence, pathophysiology, differential diagnosis, details of each treatment modality, usefulness of brainstem auditory evoked potentials monitoring, debates on the facial EMG, clinical course, and complications from the literature published from 1995 to the present time.
Collapse
Affiliation(s)
- Doo-Sik Kong
- Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | | |
Collapse
|
22
|
Gharabaghi A, Koerbel A, Löwenheim H, Kaminsky J, Samii M, Tatagiba M. The impact of petrosal vein preservation on postoperative auditory function in surgery of petrous apex meningiomas. Neurosurgery 2006; 59:ONS68-74; discussion ONS68-74. [PMID: 16888554 DOI: 10.1227/01.neu.0000219821.34450.59] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The importance of preserving the superior petrosal vein has received increasing attention in the surgical treatment of pathologies involving the petrous apex. Recent reports have associated postoperative auditory nerve dysfunction with petrosal vein sacrifice. However, there is no systematic clinical study available thus far focusing on the postoperative auditory function after petrosal vein obliteration. METHODS In 55 patients with meningiomas involving the petrous apex, pre- and intraoperative findings including petrosal vein sectioning were analyzed retrospectively concerning their impact on postoperative auditory function. RESULTS The petrosal vein was preserved in 26 (47%) cases. In 27 (49%) cases, this vein was not preserved. Hearing loss occurred in 11% of all cases. In the preserved-vein group, postoperative hearing loss occurred in 3 of 26 (11%) cases and in the sacrificed-vein group in 3 of 27 (11%) cases. CONCLUSION Sacrifice of the petrosal vein during surgery of petrous apex meningiomas seems not to have an impact on postoperative auditory function.
Collapse
MESH Headings
- Adult
- Aged
- Audiometry/standards
- Brain Edema/etiology
- Brain Edema/physiopathology
- Brain Edema/prevention & control
- Brain Stem/blood supply
- Brain Stem/pathology
- Brain Stem/surgery
- Cerebellopontine Angle/anatomy & histology
- Cerebellopontine Angle/pathology
- Cerebellopontine Angle/surgery
- Cochlear Nerve/blood supply
- Cochlear Nerve/physiopathology
- Cranial Fossa, Middle/anatomy & histology
- Cranial Fossa, Middle/pathology
- Cranial Fossa, Middle/surgery
- Cranial Fossa, Posterior/anatomy & histology
- Cranial Fossa, Posterior/pathology
- Cranial Fossa, Posterior/surgery
- Cranial Sinuses/anatomy & histology
- Cranial Sinuses/injuries
- Cranial Sinuses/surgery
- Dura Mater/pathology
- Dura Mater/surgery
- Female
- Hearing Loss, Sensorineural/etiology
- Hearing Loss, Sensorineural/physiopathology
- Hearing Loss, Sensorineural/prevention & control
- Humans
- Male
- Meningioma/physiopathology
- Meningioma/surgery
- Middle Aged
- Monitoring, Physiologic/methods
- Monitoring, Physiologic/standards
- Petrous Bone/anatomy & histology
- Petrous Bone/surgery
- Postoperative Complications/etiology
- Postoperative Complications/physiopathology
- Postoperative Complications/prevention & control
- Preoperative Care/methods
- Preoperative Care/standards
- Skull Base Neoplasms/physiopathology
- Skull Base Neoplasms/surgery
Collapse
Affiliation(s)
- Alireza Gharabaghi
- Department of Neurosurgery, University Hospital Tuebingen, Tuebingen, Germany.
| | | | | | | | | | | |
Collapse
|
23
|
Sindou MP, Polo G, Fischer C, Vial C. Chapter 23 Neurovascular conflict and hemifacial spasm. SUPPLEMENTS TO CLINICAL NEUROPHYSIOLOGY 2006; 58:274-81. [PMID: 16623339 DOI: 10.1016/s1567-424x(09)70076-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- M P Sindou
- Department of Neurosurgery, Hôpital Neurologique, University of Lyon, F-69003 Lyon, France.
| | | | | | | |
Collapse
|
24
|
Sindou MP. Microvascular decompression for primary hemifacial spasm. Importance of intraoperative neurophysiological monitoring. Acta Neurochir (Wien) 2005; 147:1019-26; discussion 1026. [PMID: 16094508 DOI: 10.1007/s00701-005-0583-6] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
There is considerable evidence that primary Hemi-Facial Spasm (HFS) is in almost all cases related to a vascular compression of the facial nerve at its Root Exit Zone (REZ) from brainstem, and that Micro-Vascular Decompression (MVD) constitutes its curative treatment. Clinical as well as electrophysiological features plead for mechanisms of the disease in structural lesions at the neural fibers (putatively: focal demyelination at origin of ephapses) and functional changes in the nuclear cells (hyperactivity of the facial nucleus). Lateral Spread Responses (LSRs) elicited by stimulation of the facial nerve branches testify of these electrophysiological perturbations. Monitoring LSRs during surgery is feasible; however the practical value of their intraoperative disappearance as control-test of an effective decompression remains controversial.MVD allows cure of the disease in most cases. Because the VIIIth nerve is at risk during surgery, intraoperative monitoring of Brainstem Auditory Evoked Potentials (BEAPs) is of value to reduce occurrence of hearing loss. Increase in latency of Peak V and decrease in amplitude of Peak I are warning-signals of an excessive stretching of the the cochlear nerve and impairment of the cochlear vascular supply, respectively.
Collapse
Affiliation(s)
- M P Sindou
- Department of Neurosurgery, Hopital Neurologique, University of Lyon, Lyon, France.
| |
Collapse
|
25
|
Polo G, Fischer C, Sindou MP, Marneffe V. Brainstem Auditory Evoked Potential Monitoring during Microvascular Decompression for Hemifacial Spasm: Intraoperative Brainstem Auditory Evoked Potential Changes and Warning Values to Prevent Hearing Loss—Prospective Study in a Consecutive Series of 84 Patients. Neurosurgery 2004; 54:97-104; discussion 104-6. [PMID: 14683545 DOI: 10.1227/01.neu.0000097268.90620.07] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2002] [Accepted: 08/27/2003] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
The nerve function of Cranial Nerve VIII is at risk during microvascular decompression for hemifacial spasm. Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) can be a useful tool to decrease the danger of hearing loss. The aim of this study was 1) to assess the side effects of surgery on hearing and describe the main intraoperative BAEP changes observed in the authors' series, and 2) to define warning values beyond which the probability of hearing impairment rises significantly. These values were calculated by correlating the (possible) postoperative hearing disturbances evaluated in terms of pure tone average with intraoperative BAEP changes (especially delay in Wave V latency).
METHODS
This series included 84 consecutive patients affected with hemifacial spasm who underwent microvascular decompression during which BAEPs were monitored. During surgery, Wave I, I to V interpeak interval, latency, and amplitude of Wave V were recorded and measured. Auditory function was studied before and after surgery and expressed as a pure tone average in all patients. Then, correlations were made between hearing impairment after surgery and intraoperative BAEP changes in an attempt to define warning values.
RESULTS
Seventy-four patients (88%) had no hearing loss after surgery (Group 1). Eight patients (9.5%) had hearing impairment with a decrease in pure tone average of more than 20 dB (Group 2). Two patients (2.3%) experienced a definitive and complete hearing loss on the side operated on (Group 3). Among intraoperative BAEP changes, latency of Peak V was the most frequently observed and the most significant phenomenon, especially during cerebellar retraction and the decompression step of the microvascular decompression procedure. In the group of patients without hearing loss (Group 1), the mean delay in latency of Peak V was 0.61 millisecond (standard deviation, ±0.36 ms); in the group with hearing decrease (Group 2), the mean delay was 1.05 milliseconds (standard deviation, ±0.64 ms); and in the group with deafness (Group 3), Wave V was abolished.
CONCLUSION
From a practical standpoint, three warning values, based on delay in latency of Peak V, were established for use during surgery: an initial one at 0.4 millisecond (“watching” signal) at the safety limit; a second one at 0.6 millisecond (risk “warning” signal), which is the mean value corresponding to the group of patients without postoperative hearing loss; and an ultimate one at 1 millisecond (“critical” warning), before irreversibility. These warnings should help the surgeon to avoid or correct maneuvers that are dangerous for hearing function, which is mandatory in functional surgery.
Collapse
Affiliation(s)
- Gustavo Polo
- Department of Neurosurgery, Hôpital Neurologique Pierre Wertheimer, Lyon, France
| | | | | | | |
Collapse
|
26
|
Abstract
BACKGROUND Intraoperative neuromonitoring (IONM) has been a valuable part of surgical procedures for over 25 years. Insight into the nervous system during surgery provides critical information to the surgeon allowing reversal or avoidance of neural insults. REVIEW SUMMARY Electrophysiological tests including electroencephalography, electromyography, and multiple types of evoked potentials (somatosensory, auditory, and motor) are monitored during surgeries that involve risk to the nervous system. Deterioration of signals suggests a surgical insult and is associated with an increased risk of postoperative deficit. Intraoperative identification of this risk allows corrective action. In addition, IONM teams make use of their armamentarium of tests to evaluate anatomy or function of the nervous system in response to specific questions posed by the surgical team. CONCLUSIONS Intraoperative recordings are now a routine part of many surgical procedures. Their correct application leads to improved surgical outcome.
Collapse
Affiliation(s)
- Robert E Minahan
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21287, USA.
| |
Collapse
|
27
|
Abstract
Acoustic neuroma results from abnormal proliferation of Schwann cells. These tumors originate in the region of Scarpa's ganglion at the junction of peripheral and central myelin of the vestibular nerve located in the internal auditory canal (IAC). The bony confine of the IAC houses the VII and the VIII cranial nerves. The presence of tumor mass compresses these structures. The growing tumor mass may also prolapses into the cerebellopontine angle (CPA). With continued growth, the tumor eventually compresses on the brain stem and cerebellum. Despite the benign nature of these tumors, the clinical course of this disease may be fraught with complications.
Collapse
Affiliation(s)
- Steven Y Ho
- Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT 06520, USA
| | | |
Collapse
|
28
|
Strauss C, Bischoff B, Neu M, Berg M, Fahlbusch R, Romstöck J. Vasoactive treatment for hearing preservation in acoustic neuroma surgery. J Neurosurg 2001; 95:771-7. [PMID: 11702866 DOI: 10.3171/jns.2001.95.5.0771] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Delayed hearing loss following surgery for acoustic neuroma indicates anatomical and functional preservation of the cochlear nerve and implies that a pathophysiological mechanism is initiated during surgery and continues thereafter. Intraoperative brainstem auditory evoked potentials (BAEPs) typically demonstrate gradual reversible loss of components in these patients. METHODS Based on this BAEP pattern, a consecutive series of 41 patients with unilateral acoustic neuromas was recruited into a prospective randomized study to investigate hearing outcomes following the natural postoperative course and recuperation after vasoactive medication. Both groups were comparable in patient age, tumor size, and preoperative hearing level. Twenty patients did not receive postoperative medical treatment. In 70% of these patients anacusis was documented and in 30% hearing was preserved. Twenty-one patients were treated with hydroxyethyl starch and nimodipine for an average of 9 days. In 66.6% of these patients hearing was preserved and in 33.3% anacusis occurred. CONCLUSIONS These results are statistically significant (p < 0.05, chi2 = 5.51) and provide evidence that these surgically treated patients suffer from a disturbed microcirculation that causes delayed hearing loss following removal of acoustic neuromas.
Collapse
Affiliation(s)
- C Strauss
- Department of Neurosurgery, University of Erlangen-Nuremberg, Erlangen, Germany.
| | | | | | | | | | | |
Collapse
|
29
|
|
30
|
Strauss C, Neu M, Bischoff B, Romstöck J. Clinical and Neurophysiological Observations after Superior Petrosal Vein Obstruction during Surgery of the Cerebellopontine Angle: Case Report. Neurosurgery 2001. [DOI: 10.1227/00006123-200105000-00043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
31
|
Strauss C, Neu M, Bischoff B, Romstöck J. Clinical and neurophysiological observations after superior petrosal vein obstruction during surgery of the cerebellopontine angle: case report. Neurosurgery 2001; 48:1157-9; discussion 1159-61. [PMID: 11334285 DOI: 10.1097/00006123-200105000-00043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
IMPORTANCE Preservation of venous drainage during surgery of the cerebellopontine angle has received little attention. CLINICAL PRESENTATION We describe changes in brainstem auditory evoked potentials after temporary obstruction of the superior petrosal vein during surgical resection of a small meningioma at the petrous apex via a standard suboccipital-lateral approach. Temporary clipping of the petrosal vein resulted in deterioration of the brainstem auditory evoked potentials. The tumor was removed with preservation of the superior petrosal vein. CONCLUSION A transient postoperative cochlear nerve deficit emphasizes the importance of venous drainage and its preservation during surgery for small lesions of the cerebellopontine angle that do not distort normal anatomic structures.
Collapse
Affiliation(s)
- C Strauss
- Department of Neurosurgery, University of Erlangen-Nürnberg, Germany.
| | | | | | | |
Collapse
|
32
|
Neu M, Strauss C, Romstöck J, Bischoff B, Fahlbusch R. The prognostic value of intraoperative BAEP patterns in acoustic neurinoma surgery. Clin Neurophysiol 1999; 110:1935-41. [PMID: 10576490 DOI: 10.1016/s1388-2457(99)00148-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Based on a consecutive series of 70 hearing patients with unilateral acoustic neurinomas and intraoperative monitoring of brain-stem auditory evoked potentials (BAEP), 4 dynamic BAEP patterns could be characterized. These patterns correspond with early and late postoperative hearing outcome. All patients with stable wave V (pattern 1) showed definite hearing preservation, all patients with irreversible abrupt loss of BAEP (pattern 2) lost their hearing, despite early hearing preservation in two cases. All patients with irreversible progressive loss of either wave I or wave V (pattern 3) eventually suffered from definite postoperative hearing loss, despite early hearing preservation in two cases. Those cases with intraoperative reversible loss of BAEP (pattern 4) showed variable short and long term hearing outcome. In 34% hearing was preserved, 44% suffered from postoperative hearing loss, the remaining 22% showed postoperative hearing fluctuation, either as a delayed hearing loss or as reversible hearing loss. Postoperative hearing fluctuation indicates anatomical and functional preservation of the cochlear nerve during surgery and is suggestive of a pathophysiological mechanism initiated during the surgical procedure and continuing thereafter. Patients at risk for delayed hearing loss can be identified during surgery by a characteristic BAEP pattern and may benefit from vasoactive treatment.
Collapse
Affiliation(s)
- M Neu
- Department of Neurosurgery, University of Erlangen-Nuremberg, Germany
| | | | | | | | | |
Collapse
|
33
|
Rizvi SS, Goyal RN, Calder HB. Hearing preservation in microvascular decompression for trigeminal neuralgia. Laryngoscope 1999; 109:591-4. [PMID: 10201746 DOI: 10.1097/00005537-199904000-00013] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE/HYPOTHESIS Sensorineural hearing loss is a disturbing complication of microvascular decompression (MVD) for trigeminal neuralgia with an incidence of 1% to 23.8%. Cerebellar retraction with increasing I-V interpeak latency (IPL) during intraoperative brainstem auditory evoked potentials (BAEP) has been identified as the chief cause of acoustic injury. This study was designed to eliminate cerebellar retraction by a modification of the standard suboccipital craniectomy. STUDY DESIGN Nine consecutive patients undergoing surgery for trigeminal neuralgia were prospectively selected for this study between 1994 and 1995. METHODS Preoperative and postoperative audiograms were obtained. Preoperative and intraoperative BAEPs were performed. The surgical modification describes initiating a partial mastoidectomy to enhance early recognition and delineation of the sigmoid and transverse sinuses crucial to maximizing the lateral extent of the craniectomy. The additional exposure gained by this technique allows for improved visualization of the brainstem without cerebellar retraction. RESULTS All patients were relieved of neuralgic pain. Postoperative IPL values were not significantly different from preoperative values (4.9+/-0.6 vs. 4.7+/-0.3 ms). Maintaining IPL of less than 1.5 ms is considered critical for preventing injury to the auditory nerve. In this study the average increase in postoperative IPL was 0.25 ms for the ipsilateral ear and 0.1 ms for the contralateral ear. CONCLUSIONS The authors offer a surgical modification of the standard suboccipital craniectomy and furnish intraoperative neurophysiologic data to demonstrate how cerebellar compression can be eliminated and hearing preserved in MVD for trigeminal neuralgia.
Collapse
Affiliation(s)
- S S Rizvi
- Department of Otolaryngology, Bay Medical Center, Bay City, Michigan, USA
| | | | | |
Collapse
|
34
|
The Predictive Value of Intraoperative Somatosensory Evoked Potential Monitoring: Review of 244 Procedures. Neurosurgery 1998. [DOI: 10.1097/00006123-199809000-00051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
35
|
Detwiler PW, Porter RW, Spetzler RF, Raudzens P. Neurophysiological monitoring during surgical treatment of skull-base tumors and vascular lesions. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s1092-440x(98)80005-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
36
|
Matthies C, Samii M. Management of vestibular schwannomas (acoustic neuromas): the value of neurophysiology for evaluation and prediction of auditory function in 420 cases. Neurosurgery 1997; 40:919-29; discussion 929-30. [PMID: 9149249 DOI: 10.1097/00006123-199705000-00007] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE From 1978 to 1993, 1000 vestibular schwannomas were operated on at the Department of Neurosurgery at Nordstadt Hospital. The goal was to improve the chances of hearing preservation by recording auditory brain stem responses (ABRs). ABRs can be used for preoperative classification of cochlear nerve impairment and for prediction of the chances of hearing preservation. PATIENTS AND METHODS In addition to the previously described audiometric testing, the patients underwent perioperative and intraoperative bilateral ABR recording at 100-dB condensation and rarefaction click stimulation. The classification system of five types of ABRs, as presented before, is based on the presence and on the latencies of Waves I, III, and V, with a special emphasis on Wave III's representing the activity of the first brain stem nuclei within the auditory pathway. According to an analysis of 420 preoperative ABRs, in case of a preoperative Type 1 or 2, the rate of hearing preservation is 80%. DISCUSSION In the case of good clinical and audiometric hearing, a severely deteriorated ABR is mostly an indicator of severe nerve compression and adhesion by the tumor. In view of subsequently reported experiences with intraoperative ABR monitoring, the value of the presented system emphasizing the importance of Wave III is stressed and discussed with other views in the literature. The criteria presented here are not designed for recognition of retrocochlear disease but aim for evaluation of the state of the auditory nerve and its perspective. CONCLUSION By the presented classification of ABR Type B1 through B5, preoperative prediction of the likelihood of hearing preservation is improved.
Collapse
Affiliation(s)
- C Matthies
- Department of Neurosurgery, Nordstadt Hospital, Hannover, Germany
| | | |
Collapse
|
37
|
Matsunaga T, Kanzaki J, Igarashi M. The limitations of hearing preservation in acoustic neuroma surgery: histological study of the interface between the eighth cranial nerve and the tumor. Acta Otolaryngol 1995; 115:269-72. [PMID: 7610819 DOI: 10.3109/00016489509139306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The interface between the eighth cranial nerve and acoustic neuroma was investigated by light microscopy and immunohistochemistry in paraffin sections in 13 patients, and in Epon sections in 19 patients. The cochlear nerve was severely invaded by tumor cells in two of six specimens examined, moderately invaded in two specimens, and not invaded in two specimens. Gliosis was frequently found within the cochlear and vestibular nerve. Hemangioma-like tissue was occasionally found attached to the cochlear and vestibular nerve adjacent to the tumor. These findings were considered to be related to difficulty in hearing preservation in some patients although acoustic neuroma surgery was successful.
Collapse
Affiliation(s)
- T Matsunaga
- Department of Otolaryngology, School of Medicine, Keio University, Tokyo, Japan
| | | | | |
Collapse
|
38
|
Preservation of Hearing in Operations on Acoustic Tumors. Neurosurgery 1995. [DOI: 10.1097/00006123-199503000-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
39
|
Taniguchi M, Schramm J. Preservation of hearing in operations on acoustic tumors: an alternative to recording brainstem auditory evoked potentials. Neurosurgery 1995; 36:623-4. [PMID: 7753369 DOI: 10.1227/00006123-199503000-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
|
40
|
Colletti V, Fiorino FG. Electrophysiologic identification of the cochlear nerve fibers during cerebello-pontine angle surgery. Acta Otolaryngol 1993; 113:746-54. [PMID: 8291433 DOI: 10.3109/00016489309135895] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To facilitate identification and preservation of the auditory nerve during cerebello-pontine angle surgery, bipolar recording of cochlear nerve compound action potentials (CNAPs) was performed. Two silver wires insulated with teflon up to the exposed ends were utilized as electrodes. They were twisted together, the distance between the two tips being 1 mm or less. Rarefaction polarity clicks (31/s) ranging from the psychoacoustical threshold to 120 dB pe SPL were used as stimuli. The investigation was performed in three groups of patients. The first group consisted of 9 patients submitted to vestibular neurectomy and 4 patients operated on by microvascular decompression of the eighth nerve. The second group comprised 8 patients with acoustic tumors smaller than 2 mm and serviceable hearing. Postoperative audiometric results in the subjects in the second group were compared with those obtained in well-matched homogeneous controls consisting of patients with acoustic neuroma operated on without the aid of CNAP recording. Bipolar recording from the eighth nerve was extremely selective, a good response being obtained only when positioning the electrode on the cochlear portion of the eighth nerve. During removal of the acoustic neuroma, repeated bipolar probing of the tumor and eighth nerve facilitated the task of distinguishing the cochlear nerve from other nervous structures and from the tumor, and contributed to preserving hearing in most patients.
Collapse
Affiliation(s)
- V Colletti
- ENT Department, University of Verona, Italy
| | | |
Collapse
|
41
|
Abstract
The authors have reviewed hearing results obtained in 99 patients operated on via the suboccipital approach for acoustic neurinoma, who were not deaf prior to surgery (pure tone average less than 70 dB). Tumor size was less than 10 mm in four cases, 10 to 19 mm in 26 cases, 20 to 29 mm in 39 cases, and 30 mm or greater in 30 cases. Removal was macroscopically complete in 92 cases and incomplete in seven, including four cases with bilateral acoustic neurofibromatosis. Hearing was preserved in 29 patients (29.3%), of whom 23 had neurinomas smaller than 30 mm and six had tumors exceeding 30 mm in size. Postoperative hearing was good in eight cases (four with neurinomas less than 20 mm and four with neurinomas greater than 20 mm), serviceable in four cases (three with neurinomas less than 20 mm and one with a tumor greater than 30 mm), and poor in 17 cases (eight with neurinomas less than 20 mm and nine with tumors greater than 20 mm). Fifty-seven patients underwent intraoperative brain-stem auditory evoked potential monitoring: the rate of hearing preservation was found to be higher in this group than in the 42 without monitoring (p less than 0.05). A statistical study using stepwise regression analysis showed that the two preoperative factors most significantly associated with postoperative hearing preservation are a good auditory level for low frequencies measured by pure tone audiometry and a small-sized tumor. Overall results indicate that, even if hearing is more easily preserved when the neurinoma is small and the preoperative auditory condition is good, the surgeon should try to save hearing in all patients who have preserved hearing before surgery.
Collapse
Affiliation(s)
- G Fischer
- Department of Neurosurgery, Hôpital Neurologique Pierre Wertheimer, Lyon, France
| | | | | |
Collapse
|
42
|
Lenarz T, Ernst A. Intraoperative monitoring by transtympanic electrocochleography and brainstem electrical response audiometry in acoustic neuroma surgery. Eur Arch Otorhinolaryngol 1992; 249:257-62. [PMID: 1524806 DOI: 10.1007/bf00714488] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The preservation of hearing is a major aim of contemporary temporal bone surgery. Our present findings demonstrate that intraoperative monitoring is a key method for attaining serviceable postoperative hearing after the removal of an acoustic neuroma. Both electrocochleography (ECoG) and brainstem electrical response audiometry were performed in 96 patients operated on for acoustic neuromas. The specificity of the different monitoring methods was affected by surgical manipulations in addition to such non-specific influences as CSF drainage, core body temperature and anesthesia. In the present study ECoG was found to be more reliable in assessing the intra- and postoperative course with respect to the preservation of cochlear function.
Collapse
Affiliation(s)
- T Lenarz
- Department of Otolaryngology, University of Tübingen, Federal Republic of Germany
| | | |
Collapse
|
43
|
Abstract
Hemifacial spasm can be diagnosed by observation and clinical history. It is thought to arise primarily from compression of the facial nerve at the pons, usually by an adjacent artery. Although many approaches to treatment have been tried, the most effective is microvascular decompression of the facial nerve at the pons. That operation has well-recognized risks, including ipsilateral deafness. The latter complication ordinarily can be avoided by the use of intraoperative monitoring of auditory evoked potentials.
Collapse
Affiliation(s)
- R H Wilkins
- Division of Neurosurgery, Duke University Medical Center, Durham, North Carolina
| |
Collapse
|