Valutazione delle aree eloquenti nelle malformazioni dello sviluppo corticale mediante risonanza magnetica funzionale

Malformations of cortical development (MCD), an important cause of drug-refractory epilepsy, may be connected with the eloquent cortical regions and have functional relevance. We evaluated by functional Magnetic Resonance Imaging (fMRI) the eloquent areas in 7 patients (1 male, 6 female, mean age 32,8 ± 13,7 yrs.) with partial epilepsy and different MCDs: giant heterotopia (1), subependimal heterotopia (1), band heterotopia (1), polymicrogyria (1), focal cortical dysplasia (3). In 4 patients the sensorimotor cortex has been acfivated by finger tapping and cutaneous stimulation; in 4 patients, with MCD involving the left hemisphere, the language areas have been activated by phonemic fluency and verbal denomination. Sensorimotor areas showed a larger activation in the affected hemisphere, and in three patients the activation involved the dysplasic tissue. A partial shift of the language areas has been also observed, with an activation cluster within the dysplasic tissue in one patient. In conclusion, fMRI is an adequate tool to map the eloquent cortex in patients with MCD. The activation within the dysplasic tissues suggests its involvement in the normal cerebral function.