Awake surgery in low-grade gliomas harboring eloquent areas: 3-year mean follow-up

Low-grade gliomas are slow-growing tumors invading eloquent areas and white matter pathways. For many decades these tumors were considered inoperable because of their high tropism for eloquent areas. However, the young age of the patients and the inescapable anaplastic transformation have recently suggested more aggressive treatments. We analyzed the neurological and neuro-oncological outcome of 12 patients who underwent surgery fully awake for the resection of LGG, harboring eloquent areas. 10 right- and 2 left-handed patients underwent pre-operative assessment: Karnofsky Performance Status, Edinburgh Handedness Inventory Score; neuropsychological and neurophysiological evaluations, according to the tumor location. During surgery we performed: sensory-motorevoked potentials, continuous electro-corticography and bipolar/monopolar cortico-subcortical mapping during neuropsychological tests. The resection rate was calculated with neuro-imaging elaboration software. No permanent post-operative deficits were reported; 2 patients improved after surgery. No impairment of cognitive functions was reported. The KPS improved in 8 patients and was steady in the others. The mean resection rate was 78.3%. The resection allowed the control of pre-operative seizures without increasing the drug intake. Awake surgery allowed a good resection rate despite the eloquent location of the tumors, without post-operative deficit. The neuropsychological outcome was unchanged after surgery. The resection seems to improve seizure control. All the patients came back to normal life and work. In conclusion, awake surgery is reliable and feasible in removal of LGG, even if invading the main eloquent areas and networks. All the patients experienced a normal life after surgery, without permanent deficits.