**3. Presurgical preparation for an awake surgery**

### **3.1 Neuropsychological evaluation**

Awake surgery for brain tumors aims to extend the life of the patient, preserve their capabilities, functionality, and quality of life through real-time intra-surgical monitoring of sensorimotor, visuospatial, language, executive, and behavioral

functions [11]. For this reason, pre- and intrasurgical work requires careful preparation in which different professionals are involved: neurosurgeon, anesthesiologist, neuropsychologist. Regarding the work of neuropsychology, the importance of its role in awake brain surgeries has been already highlighted in international protocols [12].

The presurgical neuropsychological evaluation allows to know the psychological, cognitive, and functional state of the person. A presurgical neuropsychological evaluation should include the following aspects:

**Personal aspects:** Decision-making capacity, previous experiences (especially with cancer), disposition of social and family resources, coping strategies, personality type, substance abuse, patient expectations in relation to surgery, and their disease or stress level.

**Emotional aspects:** It will especially affect the presence of anxiety. Anxiety may be related to the patient's own characteristics but also to the uncertainty associated with the disease and/or the procedure, fear, or the lack of perception of control. This is a factor that can affect attention/concentration capacity and leads to emission mistakes and generates difficulties in establishing the baseline and surgical intervention. Depressive symptoms should also be evaluated. These symptoms may be related to the tumor pathology itself, the difficult adaptation process, or other characteristics or circumstances of the patient. In any case, the preparation of a depressed patient will always require a higher level of attention from the staff.

As Boele et al. highlighted, a wide range of brain tumor patients present psychotic symptoms or hallucinations that should also be explored before surgery as well as a decrease in the level of arousal, irritability, or agitation [13].

**Cognitive factors:** The evaluation of these aspects will allow the establishment of a baseline and increase the chances of success during the intervention. Some cognitive functions have been described as basic for the correct participation of a patient in awake surgery [14]. A complete neuropsychological evaluation allows to examine normal or impaired performance and determine the strengths and weaknesses that a patient has, as well as the implications that their cognitive deficits have so that they can reintegrate, in the best way, in the activities of their daily life or at the same time. In any case, a minimum evaluation protocol should include the analysis of the following: attentional processes, language in all its aspects, amnestic processes, executive functions, and perceptual abilities. A **fluent language** to express oneself and be able to communicate cognitive and physical alterations and discomfort during surgery; **verbal comprehension** for cooperation and following instructions; **memory** to guarantee the storage of information and instructions to follow during the surgery; care for the performance of intraoperative activities and **visual skills** in case of picture-naming tasks is needed.

Most studies show that language is the cognitive domain that has been most evaluated in awake surgery. However, in recent years various tests have already been used to map other cognitive functions, such as visuospatial functions, calculation, emotions, facial recognition, or executive functions. This fact, together with the great diversity of psychological variables that must be evaluated, makes it necessary to have a neuropsychology professional within the multidisciplinary team involved in the management of awake brain surgery candidate patient. In our team, the neuropsychologist is the expert who not only supports the patient in this surgical situation but is also the professional who must determine if the affectation observed during the mapping is due to electrostimulation or if it is caused by other causes, such as problems to concentrate or psychological factors.
