Do we Need to Wake Patients up during Cortical Surgery?  - Pages 84-96

Lorena Vega-Zelaya, Rafael G. Sola, Paloma Pulido and Jesús Pastor

DOI: http://dx.doi.org/10.6000/1929-2279.2018.07.03.4

Published: 25 June2018

Abstract: In recent years, a renewed fashion for awake surgery has appeared. In spite of its undoubted utility for scientific research, this technique has several limitations and flaws, usually not debated by parts of the scientific community.

We will discuss the aims and limitations of cortical surgery, especially the points relevant to protecting the patient. These objectives should define the guidelines that direct clinical practice. We will review the awake technique as well as various tools used in intraoperative neurophysiological monitoring (IONM) to explore and monitor several cortical functions during long surgeries. The main topics discussed include electrocorticography (ECoG) and cortically recorded evoked potentials (EP), including somatosensory, visual and auditory. Later, we will discuss methods to identify and survey motor functions as motor-evoked potentials, although they are elicited trans-cranially. Finally, we will briefly discuss a promising technique to monitor some language functions in anaesthetized patients, such as cortico-cortical evoked potentials (CCEP). We will address in depth some technical questions about electrical stimulation whose full relevance are not always considered.

Finally, we will discuss why, in the absence of empirical facts showing unequivocal superiority in post-surgical outcome, we have to awaken patients, especially when an alternate possibility exists without worst clinical results, as is the case for IONM.

Keywords: Anaesthetized surgery, awake surgery, cortical mapping, cortico-cortical evoked potentials, intraoperative neurophysiological monitoring.