Case Report Differential Effects of Awake Glioma Surgery in (Critical) Language Areas on Cognition: 4 Case Studies Djaina Satoer, 1 Elke De Witte, 2 Marion Smits, 3 Roelien Bastiaanse, 4 Arnaud Vincent, 1 Peter Mariën, 2,5 and Evy Visch-Brink 1,6 1 Department of Neurosurgery, Erasmus MC University Medical Center, Rotterdam, Netherlands 2 Department of Clinical and Experimental Neurolinguistics, Free University of Brussels, Brussels, Belgium 3 Department of Radiology, Erasmus MC University Medical Center, Rotterdam, Netherlands 4 Center for Language and Cognition Groningen (CLCG), University of Groningen, Groningen, Netherlands 5 Department of Neurology and Memory Clinic, ZNA Middelheim, Antwerp, Belgium 6 Department of Neurology, Erasmus MC University Medical Center, Rotterdam, Netherlands Correspondence should be addressed to Djaina Satoer; d.satoer@erasmusmc.nl Received 2 March 2017; Accepted 21 May 2017; Published 22 June 2017 Academic Editor: Abbass Amirjamshidi Copyright © 2017 Djaina Satoer et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Awake surgery with electrocorticosubcortical stimulation is the golden standard treatment for gliomas in eloquent areas. Preoperatively, mostly mild cognitive disturbances are observed with postoperative deterioration. We describe pre- and postoperative profles of 4 patients (P1–P4) with gliomas in “critical” language areas (“Broca,” “Wernicke,” and the arcuate fasciculus) undergoing awake surgery to get insight into the underlying mechanism of neuroplasticity. Neuropsychological examination was carried out preoperatively (at T1) and postoperatively (at T2, T3). At T1, cognition of P1 was intact and remained stable. P2 had impairments in all cognitive domains at T1 with further deterioration at T2 and T3. At T1, P3 had impairments in memory and executive functions followed by stable recovery. P4 was intact at T1, followed by a decline in a language test at T2 and recovery at T3. Intraoperatively, in all patients language positive sites were identifed. Patients with gliomas in “critical” language areas do not necessarily present cognitive disturbances. Surgery can either improve or deteriorate (existing) cognitive impairments. Several factors may underlie the plastic potential of the brain, for example, corticosubcortical networks and tumor histopathology. Our fndings illustrate the complexity of the underlying mechanism of neural plasticity and provide further support for a “hodotopical” viewpoint. 1. Introduction Awake surgery is considered the golden standard treatment for low-grade gliomas (LGG) in eloquent regions to optimize tumor resection while preserving neurological and cognitive functions and hence quality of life [1, 2]. However, defcits in cognitive functions, that is, language, memory, attentional, and executive functions, occur in the (pre- and) postoperative phase of awake glioma surgery [3–5]. Eloquent regions typically include the lef dominant perisylvian brain regions. DES has provided evidence for a “hodotopical” (i.e., dynamic) view of the organization of brain functions as opposed to a “topological” viewpoint (i.e., static organization of brain functions) [6–8]. Language functions are “classically” represented in cortical areas such as Broca’s and Wernicke’s area and in the subcortical tracts that connect diferent eloquent cortical regions. LGGs typically invade functional subcortical white matter tracts. However, due to the relative slow growth rate (i.e., 4 mm a year) of LGG, neural plasticity can be facilitated [9, 10]. Tis may be the reason that, instead of moderate to severe language problems, typically mild language disorders are observed in this patient group [11]. Despite intense intraoperative monitoring, brain tumor surgery resection may induce or aggravate the existing cognitive defcits. For a long time, complete recovery within 3 months was claimed to take place, but Satoer et al. [5]. Hindawi Case Reports in Neurological Medicine Volume 2017, Article ID 6038641, 10 pages https://doi.org/10.1155/2017/6038641