Adaptation of visual cortex to damage of visual pathways in suprasellar tumors before and after gamma knife radiosurgery.

Affiliation

Centro Gamma Knife Dominicano, CEDIMAT, Plaza de la Salud, Santo Domingo, Dominican Republic. [Email]

Abstract

OBJECTIVE : To demonstrate that lesions of the visual pathways due to suprasellar tumors are accompanied by alterations of the visual cortex and to see if these alterations are reversible after treatment of tumors by gamma knife radiosurgery.
METHODS : In 36 patients with peri-optic tumors and defects of their visual fields and in an age-matched control group, magnetic resonance imaging was performed before and after treatment. T1 weighted images were evaluated by voxel-based morphometry and correlated to the degree of visual field defects.
RESULTS : In patients, grey matter density and cortical thickness were reduced in all parts of the occipital cortex, reaching significance (p < 0.05) in the left superior and middle occipital gyri, with correlation to visual field defects. Follow-up scans showed further reduction in all occipital areas.
CONCLUSIONS : As in other peripheral lesions of the optic system, damage of the optic pathways affects the visual cortex. A prospective follow-up study is needed to determine if these alterations are reversible after successful tumor treatment.

Keywords

Gamma knife radiosurgery,Neuroplasticity,Suprasellar tumors,Visual cortex,