Subscribe to RSS
DOI: 10.1055/s-0029-1225651
© Georg Thieme Verlag KG Stuttgart · New York
Are there False-negative Results of Motor Evoked Potential Monitoring in Brain Surgery?
Gibt es falsch negative Ergebnisse des Monitorings motorisch evozierter Potenziale bei Gehirnoperationen?Publication History
Publication Date:
22 October 2009 (online)
![](https://www.thieme-connect.de/media/zblneurochir/200904/lookinside/thumbnails/10.1055-s-0029-1225651-1.jpg)
Abstract
Object: The present study explores the causes of occasional postoperative pareses despite unchanged or fully recovered intraoperative motor evoked potentials (MEPs) in supratentorial brain surgeries.
Methods: In a prospective, observational design, MEP monitoring results, motor outcome, and perioperative imaging were correlated in 200 procedures for brain tumours and cortical dysplasias critically related to motor areas and pathways.
Results: Persisting pareses after unchanged or recovered MEPs occurred in four cases due to delayed ischemia, or venous congestive oedema. Transient new deficit in four cases after stable MEP monitoring occurred due to inadvertently strong stimulation bypassing the target lesion, due to marked postresectional oedema, and after cortical transsections for alleviation of epilepsy.
Discussion and Conclusions: With technically adequate MEP monitoring, truly false-negative results missing manifest corticospinal impairment do not occur. However, sustained vascular dynamics (vasospasm, congestive oedema) may cause delayed pareses which are missed, or hardly reflected by intraoperative MEP changes. Even minor MEP changes must therefore be observed to prevent impending motor deficit.
Zusammenfassung
Ziel: Die Studie untersucht die Gründe für das gelegentliche Auftreten neuer postoperativer Paresen trotz intraoperativ unveränderter oder vollständig erholter motorisch evozierter Potenziale (MEPs).
Methoden: Bei 200 Operationen von Hirntumoren und kortikalen Dysplasien in kritischer Lagebeziehung zu motorischen Arealen und Faserbahnen wurden das motorische Outcome sowie die Ergebnisse des MEP – Monitorings und der perioperativen Bildgebung prospektiv korreliert.
Ergebnisse: Bleibende Paresen trotz erhaltener oder erholter MEPs traten in vier Fällen auf, verursacht durch verzögerte Ischämien bzw. venöse Stauungsödeme. Vorübergehende neue Paresen trotz stabilen intraoperativen MEPs in weiteren vier Fällen waren durch unbeabsichtigte Stimulation kaudal der Zielläsion erklärbar, durch postresektionelles Ödem, und durch rein kortikale Affektion nach epilepsiechirurgischen multiplen subpialen Transsektionen.
Diskussion und Schlussfolgerungen: Bei technisch korrekter Durchführung des MEP – Monitorings kommen falsch-negative Ergebnisse – im strengen Sinne von nicht erfassten manifesten Schäden der kortikospinalen Bahn – nicht vor. Allerdings können fortdauernde vaskuläre Prozesse (Vasospasmus, verzögertes Stauungsödem) verspätete Paresen verursachen, die von den intraoperativen MEP – Messungen nicht ausreichend erfasst werden können. Auch geringe MEP – Veränderungen müssen beachtet werden, um drohende motorische Defizite abzuwenden.
Key words
motor evoked potentials - intraoperative monitoring - brain tumor
Schlüsselwörter
motorisch evozierte Potenziale - intraoperatives Monitoring - Hirntumor
Literatur
- 1 Cedzich C, Taniguchi M, Schafer S. et al . Somatosensory evoked potential phase reversal and direct motor cortex stimulation during surgery in and around the central region. Neurosurgery. 1996; 38 962-970
- 2 Deletis V. Intraoperative monitoring of the functional integrity of the motor pathways. Adv Neurol. 1993; 63 201-214
-
3 Deletis V, Kothbauer K. Intraoperative neurophysiology of the corticospinal tract. In: Staalberg E, Sharma, H.S., Olsson, Y. (ed)
Spinal Cord Monitoring . Vienna, New York, Springer 1998 pp 421-444 - 4 Dong CC, Macdonald DB, Akagami R. et al . Intraoperative facial motor evoked potential monitoring with transcranial electrical stimulation during skull base surgery. Clin Neurophysiol. 2005; 116 588-596
- 5 Kang DZ, Wu ZY, Lan Q. et al . Combined monitoring of evoked potentials during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Chin Med J (Engl). 2007; 120 1567-1573
- 6 Kombos T, Suess O, Ciklatekerlio O. et al . Monitoring of intraoperative motor evoked potentials to increase the safety of surgery in and around the motor cortex. J Neurosurg. 2001; 95 608-614
- 7 Kumabe T, Higano S, Takahashi S. et al . Ischemic complications associated with resection of opercular glioma. J Neurosurg. 2007; 106 263-269
- 8 Neuloh G, Pechstein U, Cedzich C. et al . Motor evoked potential monitoring with supratentorial surgery. Neurosurgery. 2004; 54 1061-1070 discussion 1070-1062
- 9 Neuloh G, Pechstein U, Schramm J. Motor tract monitoring during insular glioma surgery. J Neurosurg. 2007; 106 582-592
-
10 Neuloh G, Schramm J. Intraoperative neurophysiological mapping and monitoring for supratentorial procedures. In: Deletis V (ed)
Neurophysiology in Neurosurgery . Amsterdam, Boston, London, Academic Press 2002 pp 339-401 - 11 Neuloh G, Schramm J. Monitoring of motor evoked potentials compared with somatosensory evoked potentials and microvascular Doppler ultrasonography in cerebral aneurysm surgery. J Neurosurg. 2004; 100 389-399
- 12 Neuloh G, Schramm J. Motor evoked potential monitoring for the surgery of brain tumours and vascular malformations. Adv Tech Stand Neurosurg. 2004; 29 171-228
- 13 Neuloh G, Simon M, Schramm J. Stroke prevention during surgery for deep-seated gliomas. Neurophysiol Clin. 2007; 37 383-389
- 14 Pechstein U, Cedzich C, Nadstawek J. et al . Transcranial high-frequency repetitive electrical stimulation for recording myogenic motor evoked potentials with the patient under general anesthesia. Neurosurgery. 1996; 39 335-343 discussion 343-334
- 15 Sala F, Krzan MJ, Jallo G. et al . Prognostic value of motor evoked potentials elicited by multipulse magnetic stimulation in a surgically induced transitory lesion of the supplementary motor area: a case report. J Neurol Neurosurg Psychiatry. 2000; 69 828-831
- 16 Sala F, Lanteri P. Brain surgery in motor areas: the invaluable assistance of intraoperative neurophysiological monitoring. J Neurosurg Sci. 2003; 47 79-88
- 17 Szelenyi A, Kothbauer KF, Deletis V. Transcranial electric stimulation for intraoperative motor evoked potential monitoring: Stimulation parameters and electrode montages. Clinical Neurophysiology. 2007; 118 1586-1595
- 18 Szelenyi A, Langer D, Kothbauer K. et al . Monitoring of muscle motor evoked potentials during cerebral aneurysm surgery: intraoperative changes and postoperative outcome. J Neurosurg. 2006; 105 675-681
- 19 Taniguchi M, Cedzich C, Schramm J. Modification of cortical stimulation for motor evoked potentials under general anesthesia: technical description. Neurosurgery. 1993; 32 219-226
-
20 Wiesendanger M. Organization of secondary motor areas of cerebral cortex. In: Brookhart JM MV (ed)
The Nervous System . Methesda, MD, USA, American Physiological Society 1981 pp 1121-1147 - 21 Zentner J, Hufnagel A, Pechstein U. et al . Functional results after resective procedures involving the supplementary motor area. J Neurosurg. 1996; 85 542-549
- 22 Zhou HH, Kelly PJ. Transcranial electrical motor evoked potential monitoring for brain tumor resection. Neurosurgery. 2001; 48 1075-1080 discussion 1080-1071
Correspondence
Dr. G. Neuloh
Klinik und Poliklinik für Neurochirurgie
Sigmund-Freud-Straße 25
53105 Bonn
Germany
Phone: 0228-28716521
Fax: 0228-28715827
Email: georg.neuloh@ukb.uni-bonn.de