Surgery for gliomas involving the left inferior parietal lobule: new insights into the functional anatomy provided by stimulation mapping in awake patients

Clinical article

Restricted access


Surgery in the left dominant inferior parietal lobule (IPL) is challenging because of a high density of somatosensory and language structures, both in the cortex and white matter. In the present study, on the basis of the results provided by direct cerebral stimulation in awake patients, the authors revisit the anatomofunctional aspects of surgery within the left IPL.


Fourteen consecutive patients underwent awake craniotomy for a glioma involving the left IPL. Intraoperative motor, sensory, and language mapping was performed before and during the tumor removal, at both the cortical and subcortical levels, to optimize the extent of resection, which was determined based on functional boundaries. Anatomofunctional correlations were performed by combining the results of intraoperative mapping and those provided by pre- and postoperative MR imaging.


At the cortical level, the primary somatosensory area (retrocentral gyrus) limited the resection anteriorly in all cases, at least partially. Less frequently, speech arrest or articulatory problems were observed within the parietal operculum (4 cases). The lateral limit was determined by language sites that were variably distributed. Anomia was the most frequent response (9 cases) at the posterior third of the superior (and/or middle) temporal gyrus. Posteriorly, less reproducible reorganized language sites were seldom observed in the posterior portion of the angular gyrus (2 cases). At the subcortical level, in addition to somatosensory responses due to stimulation of the thalamocortical pathways, articulatory disturbances were induced by stimulation of white matter in the anterior and lateral part of the surgical cavity (11 cases). This tract anatomically corresponds to the horizontal portion of the lateral segment of the superior longitudinal fascicle (SLF III). Deeper and superiorly, phonemic paraphasia was the main language disturbance (12 cases), elicited by stimulation of the posterosuperior portion of the arcuate fascicle. All these eloquent structures were surgically preserved. Despite slight cognitive disorders (working memory, writing, or calculation) in 6 cases, no patient retained a severe or a moderate postoperative deficit (except one with right hemianopia [mean follow-up 41.8 months]). Resection was total or near total in 9 patients and partial in 3 cases.


To the authors' knowledge, this is the first series dedicated to the surgery of gliomas involving the left IPL. Interestingly, a certain degree of interindividual variability was observed in the distribution of the cortical maps, especially for language. Therefore, it is suggested that no rigid pattern of resection can be considered within the left IPL, and that surgery in this region should be performed in awake patients to adapt the tumor removal to individual functional limits. Nonetheless, several landmarks have been regularly identified, especially at the subcortical levels (SLF III and arcuate fascicle); a better knowledge of these functional tracts could be helpful to optimize functional outcomes.

Abbreviations used in this paper: DO 80 = picture-naming test; DT = diffusion tensor; IPL = inferior parietal lobule; IPS = intraparietal sulcus; SLF = superior longitudinal fascicle; SLF III = lateral fibers of the horizontal portion of the SLF; SMG = supramarginal gyrus; SPL = superior parietal lobule; T1p = posterior portion of the superior temporal gyrus; T2p = posterior portion of the middle temporal gyrus.

Article Information

Address correspondence to: Hugues Duffau, M.D., Ph.D., Département de Neurochirurgie, Hôpital Gui de Chauliac, CHU Montpellier, 80 Avenue Augustin Fliche, 34295 Montpellier, France. email:

Please include this information when citing this paper: published online June 24, 2011; DOI: 10.3171/2011.5.JNS112.

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Case 4. Intraoperative view of functional cortical mapping before tumor resection. The patient's head is turned to the right. The tags with the letters A–F represent the boundaries of the tumor as identified by ultrasonography. The numbered tags mark functional sites detected by direct cerebral stimulation under local anesthesia. In order from right to left: 1 = primary motor area of the face (precentral gyrus); 10 = speech arrest during counting (parietal operculum) and dysesthesias (sensory zones, postcentral gyrus); 2 = tongue; 9 = lips; 3 and 4 = hand (lateral portion) and fingers (thumb and index); 6 and 7 = hand (medial portion); 8 = forearm; 11 and 13 = speech apraxia; 14 = anomia and semantic paraphasias (T1p–SMG transition); and 12 = syntactical problems (T2p).

  • View in gallery

    Summary of sites where language interference was induced by cortical electrostimulation during picture naming (using the DO-80) in 14 patients who were undergoing surgery for a glioma in the left IPL. The picture is oriented as in the operative position. ∅ = speech arrest; ▵ = anomia; ▴ = semantic paraphasia; □ = phonological paraphasia; ▪ = articulatory troubles; ⋄ = word telescoping; ♦ = noun gender error; × = increased latency; + = syntactic problems; Ψ = perseveration; ε = hesitation.

  • View in gallery

    Summary of sites where contralateral sensorimotor responses were induced by cortical electrostimulation in 14 patients who were undergoing surgery for a glioma in the left IPL. The picture is oriented as in the operative position. Symbols mark involuntary movements: = hand/fingers; = face; = upper limb; = mouth; and dysesthesias: uncircled 1 = hand; = fingers; = upper limb; = face; = tongue; = lips.

  • View in gallery

    Case 4. A: Intraoperative view of a subcortical functional mapping after tumor removal. The patient's head is turned to the right. The numbered tags mark functional sites in the white matter that were detected by direct cerebral stimulation under local anesthesia. In the superficial white matter under the cortical sites, the numbered tags represent the following: 44 = anomia (under T2p-AG); 49 = semantic paraphasia (under T1p); and 45 = articulatory troubles. In the deep white matter, the numbered tags represent the following: 50, 46, and 47 = phonemic paraphasias; 48 = upper-limb dysesthesias and slowness of movements. B: Postoperative T1-weighted sagittal MR imaging study showing enhancement at the site where phonemic paraphasias were induced (arrow), which led us to stop the resection, leaving a tumor residue in the depth of the surgical cavity.

  • View in gallery

    Schematic drawings of the main fiber bundles encountered in the region of the left IPL. The picture is oriented as in the operative position. A: Horizontally oriented fiber bundles near the frontal and parietal opercula: the opercular segment of the SLF (SLF III) eliciting articulatory disturbances during stimulation (circle). B: In the deep white matter, the arcuate fascicle (arc) is seen, eliciting phonological paraphasia when stimulated (circle). Ag = angular gyrus; F1 = superior frontal gyrus; F2 = middle frontal gyrus; F3 = inferior frontal gyrus; SMg = supramarginal gyrus; T1 = superior temporal gyrus; T2 = middle temporal gyrus; T3 = inferior temporal gyrus.



Bartolomeo PThiebaut de Schotten MDuffau H: Mapping of visuospatial functions during brain surgery: a new tool to prevent unilateral spatial neglect. Neurosurgery 61:E13402007


Berger MSDeliganis AVDobbins JDKeles GE: The effect of extent of resection on recurrence in patients with low grade cerebral hemisphere gliomas. Cancer 74:178417911994


Cascino GDHulihan JFSharbrough FWKelly PJ: Parietal lobe lesional epilepsy: electroclinical correlation and operative outcome. Epilepsia 34:5225271993


Catani MJones DKffytche DH: Perisylvian language networks of the human brain. Ann Neurol 57:8162005


Cramer SCMoore CIFinklestein SPRosen BR: A pilot study of somatotopic mapping after cortical infarct. Stroke 31:6686712000


De Benedictis AMoritz-Gasser SDuffau H: Awake mapping optimizes the extent of resection for low-grade gliomas in eloquent areas. Neurosurgery 66:107410842010


De Witt Hamer PCMoritz-Gasser SGatignol PDuffau H: Is the human left middle longitudinal fascicle essential for language? A brain electrostimulation study. Hum Brain Mapp 32:9629732011


Deloche GHannequin D: DO 80: Test de dénomination orale d'images ParisLes Editions du Centre de Psychologie Appliquée1997


Desmurget MBonnetblanc FDuffau H: Contrasting acute and slow-growing lesions: a new door to brain plasticity. Brain 130:8989142007


Duffau H: The anatomo-functional connectivity of language revisited. New insights provided by electrostimulation and tractography. Neuropsychologia 46:9279342008


Duffau H: Awake surgery for nonlanguage mapping. Neurosurgery 66:5235292010


Duffau H: Brain plasticity and tumors. Adv Tech Stand Neurosurg 33:3332008


Duffau H: Intraoperative cortico-subcortical stimulations in surgery of low-grade gliomas. Expert Rev Neurother 5:4734852005


Duffau H: Lessons from brain mapping in surgery for low-grade glioma: insights into associations between tumour and brain plasticity. Lancet Neurol 4:4764862005


Duffau H: New concepts in surgery of WHO grade II gliomas: functional brain mapping, connectionism and plasticity—a review. J Neurooncol 79:771152006


Duffau H: Surgery of low-grade gliomas: towards a ‘functional neurooncology’. Curr Opin Oncol 21:5435492009


Duffau HCapelle L: [Functional recuperation after resection of gliomas infiltrating primary somatosensory fields. Study of perioperative electric stimulation.]. Neurochirurgie 47:5345412001. (Fr)


Duffau HCapelle LDenvil DSichez NGatignol PTaillandier L: Usefulness of intraoperative electrical subcortical mapping during surgery for low-grade gliomas located within eloquent brain regions: functional results in a consecutive series of 103 patients. J Neurosurg 98:7647782003


Duffau HCapelle LSichez NDenvil DLopes MSichez JP: Intraoperative mapping of the subcortical language pathways using direct stimulations. An anatomo-functional study. Brain 125:1992142002


Duffau HGatignol PDenvil DLopes MCapelle L: The articulatory loop: study of the subcortical connectivity by electrostimulation. Neuroreport 14:200520082003


Duffau HGatignol PMandonnet ECapelle LTaillandier L: Intraoperative subcortical stimulation mapping of language pathways in a consecutive series of 115 patients with Grade II glioma in the left dominant hemisphere. J Neurosurg 109:4614712008


Duffau HGatignol PMandonnet EPeruzzi PTzourio-Mazoyer NCapelle L: New insights into the anatomo-functional connectivity of the semantic system: a study using cortico-subcortical electrostimulations. Brain 128:7978102005


Duffau HGatignol PMoritz-Gasser SMandonnet E: Is the left uncinate fasciculus essential for language? A cerebral stimulation study. J Neurol 256:3823892009


Duffau HLopes MArthuis FBitar ASichez JPVan Effenterre R: Contribution of intraoperative electrical stimulations in surgery of low grade gliomas: a comparative study between two series without (1985–96) and with (1996–2003) functional mapping in the same institution. J Neurol Neurosurg Psychiatry 76:8458512005


Duffau HVelut SMitchell MCGatignol PCapelle L: Intraoperative mapping of the subcortical visual pathways using direct electrical stimulations. Acta Neurochir (Wien) 146:2652702004


Gil-Robles SDuffau H: Surgical management of World Health Organization Grade II gliomas in eloquent areas: the necessity of preserving a margin around functional structures. Neurosurg Focus 28:2E82010


Glasser MFRilling JK: DTI tractography of the human brain's language pathways. Cereb Cortex 18:247124822008


Goodglass HKaplan EBarresi B: The Assessment of Aphasia and Related Disorders ed 3PhiladelphiaLippincott Williams & Wilkins2001


Grant GAFarrell DSilbergeld DL: Continuous somatosensory evoked potential monitoring during brain tumor resection. Report of four cases and review of the literature. J Neurosurg 97:7097132002


Hommet CBardet Fde Toffol BPerrier DBiraben AVignal JP: Unilateral spatial neglect following right inferior parietal cortectomy. Epilepsy Behav 5:4164192004


Hurwitz LJAdams GF: Rehabilitation of hemiplegia: indices of assessment and prognosis. BMJ 1:94981972


Jang SH: Contra-lesional somatosensory cortex activity and somatosensory recovery in two stroke patients. J Rehabil Med 43:2682702011


Jang SHAhn SHLee JCho YWSon SM: Cortical reorganization of sensori-motor function in a patient with cortical infarct. NeuroRehabilitation 26:1631662010


Kiriyama IMiki HKikuchi KOhue SMatsuda SMochizuki T: Topographic analysis of the inferior parietal lobule in high-resolution 3D MR imaging. AJNR Am J Neuroradiol 30:5205242009


Lafargue GDuffau H: Awareness of intending to act following parietal cortex resection. Neuropsychologia 46:266226672008


Makris NKennedy DNMcInerney SSorensen AGWang RCaviness VS Jr: Segmentation of subcomponents within the superior longitudinal fascicle in humans: a quantitative, in vivo, DT-MRI study. Cereb Cortex 15:8548692005


Mandonnet ENouet AGatignol PCapelle LDuffau H: Does the left inferior longitudinal fasciculus play a role in language? A brain stimulation study. Brain 130:6236292007


Martino JBrogna CRobles SGVergani FDuffau H: Anatomic dissection of the inferior fronto-occipital fasciculus revisited in the lights of brain stimulation data. Cortex 46:6916992010


Metz-Lutz MNKremin HDeloche GHannequin DFerrand IPerrier-Palisson D: Standardisation d'un test de dénomination orale: contrôle de l'âge, du sexe et du niveau de scolarité chez des sujets adultes normaux. Revue de Neuropsychologie 1:73951991


Ojemann GOjemann JLettich EBerger M: Cortical language localization in left, dominant hemisphere. An electrical stimulation mapping investigation in 117 patients. J Neurosurg 71:3163261989


Oldfield RC: The assessment and analysis of handedness: the Edinburgh inventory. Neuropsychologia 9:971131971


Penfield WBoldrey E: Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 60:3894431937


Pouratian NBookheimer SY: The reliability of neuroanatomy as a predictor of eloquence: a review. Neurosurg Focus 28:2E32010


Rossini PMTecchio FPizzella VLupoi DCassetta EPasqualetti P: Interhemispheric differences of sensory hand areas after monohemispheric stroke: MEG/MRI integrative study. Neuroimage 14:4744852001


Rossini PMTecchio FPizzella VLupoi DCassetta EPasqualetti P: On the reorganization of sensory hand areas after mono-hemispheric lesion: a functional (MEG)/anatomical (MRI) integrative study. Brain Res 782:1531661998


Russell SMElliott RForshaw DKelly PJGolfinos JG: Resection of parietal lobe gliomas: incidence and evolution of neurological deficits in 28 consecutive patients correlated to the location and morphological characteristics of the tumor. J Neurosurg 103:101010172005


Sanai NMirzadeh ZBerger MS: Functional outcome after language mapping for glioma resection. N Engl J Med 358:18272008


Szelényi ABello LDuffau HFava EFeigl GCGalanda M: Intraoperative electrical stimulation in awake craniotomy: methodological aspects of current practice. Neurosurg Focus 28:2E72010


Thiebaut de Schotten MUrbanski MDuffau HVolle ELévy RDubois B: Direct evidence for a parietal-frontal pathway subserving spatial awareness in humans. Science 309:222622282005


Van Buskirk CWebster D: Prognostic value of sensory defect in rehabilitation of hemiplegics. Neurology 5:4074111955


Vigneau MBeaucousin VHervé PYDuffau HCrivello FHoudé O: Meta-analyzing left hemisphere language areas: phonology, semantics, and sentence processing. Neuroimage 30:141414322006




All Time Past Year Past 30 Days
Abstract Views 53 53 33
Full Text Views 181 181 17
PDF Downloads 67 67 10
EPUB Downloads 0 0 0


Google Scholar