The insular lobe and brain plasticity: Lessons from tumor surgery.
OBJECTIVE
Despite recent literature supporting the likely role of the insula in many functions, the actual participation of this multimodal lobe in the brain functioning remains unclear, i.e. has the insula an essential or compensable role?


METHODS
We surgically resected an insular low-grade glioma, using intraoperative electrical stimulation, in 42 patients who experienced seizures, but who presented no or only a slight neurological deficit. Surgery was performed under local anesthesia in patients with a lesion in the dominant hemisphere. The resection was systematically stopped according to cortico-subcortical functional boundaries.


RESULTS
Intraoperative electrical mapping induced language disturbances, pain and vertigo, but no other side effects were observed. Post-operatively, the patients experienced a transient hemiparesis in 21 cases, language disorders in 10 cases, an athymhormic syndrome in 7 cases, a Foix-Chavany-Marie syndrome in 3 cases, and micturition disturbances in one case. Despite this immediate post-surgical worsening, all the patients recovered their preoperative neurological status within 3 months, except in three cases due to a deep stroke.


CONCLUSIONS
These results show that the insula, a complex associative multimodal structure poorly studied until now, can be functionally compensated. Such a plastic potential may have important fundamental and clinical implications, in particular in the field of oncological neurosurgery.
Duffau
Hugues
H
Departments of Neurosurgery and Inserm U678, Hôpital Salpêtrière, 47-83 Bd de l'hôpital, 75651 Paris Cedex 13, France. hugues.duffau@psl.ap-hop-paris.fr
Taillandier
Luc
L
Gatignol
Peggy
P
Capelle
Laurent
L
D000328:Adult; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D017567:Karnofsky Performance Status; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology; D016896:Treatment Outcome