Crossed aphasia elicited by intraoperative cortical and subcortical stimulation in awake patients: Clinical article

Department of Neurosurgery, Hôpital Gui de Chauliac, Centre Hospitalier Universitaire, Montpellier, France.
Journal of Neurosurgery (Impact Factor: 3.74). 12/2010; 113(6):1251-8. DOI: 10.3171/2010.6.JNS10719
Source: PubMed


Crossed aphasia (aphasia resulting from a right hemispheric lesion among right-handed patients) is rare. The authors describe for the first time transient crossed aphasia elicited by intraoperative electrostimulation of both cortex and white matter pathways in awake patients.
Three right-handed adults underwent surgery for a right-sided glioma. Because slight language disorders occurred during partial seizures or were identified on preoperative cognitive assessment, with right activations detected on language functional MR imaging in 1 patient, awake craniotomy was performed using intraoperative cortico-subcortical electrical functional mapping.
Transient language disturbances were elicited by stimulating discrete cortical areas (inferior frontal gyrus and posterior part of the superior temporal gyrus) and white matter pathways (inferior frontooccipital fasciculus and arcuate fasciculus). A subtotal resection was achieved in all cases, according to functional boundaries. Postoperatively, 1 patient experienced a transient dysphasia, which resolved after speech rehabilitation, with no permanent deficit.
These original findings highlight the possibility of finding crucial cortico-subcortical language networks in the right hemisphere in a subgroup of atypical right-handed patients. These findings provide new insights into the neural basis of language, by underlining the role of the right inferior occipitofrontal fasciculus in semantics and that of the right arcuate fasciculus in phonology, and by supporting the hypothesis of a mirror organization between the right and left hemispheres. The authors suggest that, in right-handed patients, if language disturbances are detected during seizures or on presurgical neuropsychological assessment, especially when right activations are observed on language functional MR imaging, awake craniotomy with intraoperative language mapping should be considered.

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    • "Knowledge on the organization of propositional language in the right hemisphere comes from the analysis of aphasic patients with damage to the right hemisphere (see Alexander et al., 1989a; Mariën et al., 2004) and from a case series study of intraoperative cortical-subcortical stimulation (Vassal et al., 2010). Vassal coworkers (2010) performed intraoperative cortical-subcortical electrical functional mapping in three right-handed adults who had right-sided low-grade gliomas. "
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