Intraoperative preservation of corticospinal function in the brainstem

Abstract

MEP monitoring-as opposed to SEPs-is a valid indicator of corticospinal function in brainstem-related surgery, independent from the type of lesion operated on. New deficit occurs only after more pronounced MEP changes than in supratentorial surgery, but complete loss as in spinal surgery is not required. MEPs may help to prevent permanent new paresis.

Motor-evoked potentials (MEP) during brainstem surgery to preserve corticospinal function

“…The criterion adopted in our study lead to a warning issued in 39 surgical interventions (38%). This rate of significant MEP changes is in-between those of two previous studies on MEP in brainstem surgery (46% [12], 22% [3]). The warning rate may partly depend on the number of children in the patient population, as children require higher MEP thresholds [6].…”

“…Furthermore, it has been shown that sensitive warning criteria trigger surgical reevaluation earlier [1,12]. The criterion adopted in our study lead to a warning issued in 39 surgical interventions (38%).…”

“…To date, only few publications have described monitoring of CST function by Motor Evoked Potentials (MEPs) during surgery for intra-and extraparenchymal brainstem lesions [3,12]. Although MEPs are well established for the early detection of impending motor deficit during surgery of cranial procedures [10,11,14,17,19] and the spinal cord [1,5,15,16], for brainstem surgery a warning criterion has not yet become generally accepted.…”

Intraoperatives neurophysiologisches Monitoring verbessert das Outcome in der Neurochirurgie

“…Bei der ersten Gruppe von Verfahren, dem eigentlichen Monitoring, wird die Funktion der Nervenbahnen kontinuierlich überwacht [12,[14][15][16][17][18][19][20]. Die Messungen werden jeweils sofort ausgewertet, indem sie mit den Ausgangswerten zu Beginn der Operation verglichen werden (Abbildung 1).…”

“…Bei intrakraniellen Eingriffen wird schon eine Amplitudenreduktion als Warnzeichen angesehen [18]. Bei Eingriffen am Hirnstamm werden optimale Warnkriterien noch diskutiert [19,20,29] .…”