Table 1.
List of the studies having addressed preoperative brain reorganization.
| Study | Number of patients | Glioma location | Glioma grade | Technique | Function/network | Contralesional activation | High inter-subject variability | Notes |
|---|---|---|---|---|---|---|---|---|
| Sensorimotor system | ||||||||
| Baciu et al., 2003 | 12 (+ venous malformations) | L or R motor (rolandic or extra-rolandic) | Both | fMRI | Motor | x | ||
| Caramia et al., 1998 | 7 | Either hemisphere | Both | TMS | Motor | x | ||
| Carpentier et al., 2001 | 17 (including other patient populations) | L or R primary sensorimotor cortex | Both | fMRI | Motor | Lower degree of reorganization than in congenital conditions | ||
| Fandino et al., 1999 | 11 | Close/in L or R central region (M1) | Both | fMRI | Motor | x | ||
| Krainik et al., 2001 | 23 (including 1 dysplasia) | L or R medial frontal (SMA) | Both (LGG and grade III) | fMRI | Motor | x | ||
| Krainik et al., 2003 | 12 | L or R medial frontal (SMA) | LGG | fMRI | Motor | x | Contralesional activation especially in the patients with transient postoperative deficits | |
| Meyer et al., 2003b | 9 (including 5 other tumoral and non-tumoral lesions) | L or R SM cortex | Both | PET | Motor | x | Contralesional activation especially in the patients with deficits | |
| Niu et al., 2014 | 15 | Close/in L or R motor areas | N/A | fMRI (also connectivity) | Motor | Decreased connectivity between L and R PMC, but nit within these areas the SMA | ||
| Roux et al., 2000 | 5 (including 1 MG and 1 metastasis) | Close/in L or R motor strip | Both | fMRI and IOM | Motor | x | Contralesional activation alternatively attributed to the recruitment of proximal limb muscles (which normally determine a bilateral activation) or to increased effort | |
| Tozakidou et al., 2013 | 87 (including non-glioma tumors) | L or R central region | Both | fMRI | Motor | x | ||
| Tuntiyatorn et al., 2011 | 8 (including 3 AVM) | L or R M1 | Both | fMRI | Motor | x | x | |
| Wunderlich et al., 1998 | 6 | L or R precentral | Both | PET and MEP | Motor | Reorganization also dependent on specific tumor location (dorsal tumor growth determined ventral displacement associated with preserved function vs. ventrally growing tumors) | ||
| Yoshiura et al., 1997 | 7 (including 3 MG and 2 metastases) | L or R pericentral area | Both | fMRI | Motor | x | Contralesional activation especially in the patients with deficits | |
| Language system | ||||||||
| Benzagmout et al., 2007 | 7 | L Broca | LGG | fMRI and IOM | Language | x | ||
| Briganti et al., 2012 | 39 | LH | Both | fMRI (and connectivity) | Language | |||
| Buklina et al., 2013 | 22 (including 2 MG) | Language- dominant hemisphere | Both | fMRI and functional asymmetry testing | Language | x | x | Still LH-dominance for grade I gliomas, MG, and GBM |
| Chan et al., 2019 | 1 | L IFG including Broca | LGG | IOM | Language | N/A | ||
| Cho et al., 2018 | 43 | L Broca | Both | fMRI | Language | x | possible neurovascular uncoupling masking perilesional activation | |
| De Benedictis et al., 2012 | 1 | L frontal (including Broca) | LGG | IOM | Language | N/A | ||
| Deng et al., 2015 | 38 | L frontal, temporal, parietal (including Broca and Wernicke) | Both | fMRI | Language | Lower plasticity than in patients with AVM | ||
| Duffau et al., 2001 | 1 | L insula | LGG | fMRI and IOM | Language | x | ||
| Duffau et al., 2006 | 12 | L insula | LGG | IOM | Language | N/A | ||
| Holodny et al., 2002 | 1 | L insula, IFG, anterior temporal, and basal ganglia | HGG (grade III) | fMRI | Language | x | ||
| Ille et al., 2019 | 18 | L perisylvian | Both | nrTMS | Language | N/A | Two assessments spaced 17 ± 12 months: Greater reshaping in lower grade gliomas and when assessments spaced > 13 months | |
| Krieg et al., 2013 | 15 (including 2 cavernomas) | L language-eloquent | Both | rTMS | Language | x | ||
| Li et al., 2019 | 1 | L fronto-temporal insular (including Broca) | LGG | fMRI (and connectivity) | Language | x | x | R Broca's area homologue developed the expected connections with the other language-related areas, but indirect connection with Wernicke's area (still in LH) |
| Lubrano et al., 2010 | 16 (including 3 cavernomas and 6 circumscribed non-glioma tumors) | Dominant IFG | Both | IOM | Language | N/A | x | |
| Meyer et al., 2003a | 7 (including 5 other tumoral and non-tumoral lesions) | L perisylvian cortex | Both | PET | Language | x | ||
| Partovi et al., 2012 | 57 (including 20 other tumoral and non-tumoral lesions) | L Broca or Wernicke | Both | fMRI | Language | x | x | |
| Petrovich et al., 2004 | 1 | L temporo-parietal | HGG (grade III) | fMRI and IOM | Language | x | ||
| Plaza et al., 2009 | 1 | L frontal | LGG | IOM | Language | N/A | ||
| Rösler et al., 2014 | 50 | Close to L language-eloquent areas | Both | nTMS | Language | x | ||
| Sanai et al., 2008 | 250 | L or R language areas | Both | IOM | Language | N/A | x | |
| Thiel et al., 2001 | 61 | LH | Suspected LGG (but also HGG and other lesions) | PET | Language | x | Contralesional activation also involving the cerebellum | |
| Thiel et al., 2005 | 14 | LH (including IFG) | Both | rTMS | Language | x | ||
| Thiel et al., 2006 | 17 | L temporal or frontal | Both | PET and rTMS | Language | x | ||
| Tantillo et al., 2016 | 20 | LH | Both | fMRI and DTI | Language | x | x | Higher corpus callosum anisotropy in the patients with codominant vs. left-lateralized language. In HGG vs. LGG, greater variability in the lateralization indices and more frequent bilateral activation |
| Ulmer et al., 2003 | 1 | L frontal | LGG | fMRI and IOM | Language | x | Discrepancy between fMRI showing almost only RH activation and IOM confirming LH dominance | |
| Voets et al., 2019 | 44 | Language-dominant hemisphere | Both | fMRI | Language | x | x | |
| Zhang et al., 2018 | 78 | L language network | Both | sMRI (+resting-state functional connectivity) | Language | x | In LGG (but not HGG), higher gray-matter volume in medial bilateral cerebellar lobule VII (region with increased spontaneous brain activity in the left hemisphere) + increase in functional connectivity | |
| Zheng et al., 2013 | 10 | L frontal | LGG | DTI | Language | Increased left-lateralization of some language fascicles (i.e., ILF and IFOF), involved in compensation | ||
| Sensorimotor and language systems | ||||||||
| Almairac et al., 2018 | 84 | L or R insula | LGG | sMRI | None | x | ||
| Herbet et al., 2016 | 231 | Either hemisphere | LGG | IOM | Language, sensory, motor | Definition of an atlas of cortical and subcortical plasticity, showing low WM plasticity | ||
| Ius et al., 2011 | 58 | Close/in eloquent areas in either hemisphere | LGG | IOM | Language, sensory, motor | N/A | Defined a 'minimal common brain' of structures with low compensation potential (especially WM) | |
| Ojemann et al., 1996 | 14 | Close to eloquent areas in either hemisphere | Both | IOM and extraoperative mapping | Language, somatosensory, motor | Persistence of the activation in the affected area | ||
| Ulmer et al., 2004 | 50 (including non-neoplastic lesions) | Eloquent areas in either hemisphere | Not specified | fMRI and additional methods (e.g., IOM) | Language, motor, and visual | Commented possible neurovascular uncoupling masking perilesional activation | ||
| Zimmermann et al., 2019 | 13 (including 2 AVM/hemangiomas) | Close to L or R sensorimotor cortex | Both | fMRI and MEG | Motor and somatosensory | x | x | General agreement between fMRI and MEG results |
Note. AVM = arteriovenous malformation; DTI = diffusion tensor imaging; fMRI = functional magnetic resonance imaging; GBM = glioblastoma; HGG = high-grade glioma; IFOF = Inferior fronto-occipital fasciculus; ILF = inferior longitudinal fasciculus; IOM = intraoperative mapping; LGG = low-grade glioma; L(H) = left (hemisphere); M1 = primary motor cortex; MEG = magnetoencephalography; MEP = motor evoked potentials; MG = meningioma; N/A = not tested; n(r)TMS = navigated (repetitive) transcranial magnetic stimulation; PET = positron emission tomography; PMC = premotor cortex; Post = postoperative; Pre = preoperative; R(H) = right (hemisphere); SMA = supplementary motor cortex; sMRI = structural magnetic resonance imaging.