Functional MRI in malformations of cortical development: activation of dysplastic tissue and functional reorganization.
OBJECTIVE
Functional neuroimaging and electrophysiological studies suggest that dysplastic neural tissue in malformations of cortical development may participate in task performance, and that functional organization can be altered beyond visible lesion boundaries. The aim of this work was to investigate cortical function in a heterogeneous group of patients with malformations of cortical development.


METHODS
Twelve patients participated in the study, 2 for each of the following categories: subcortical, periventricular, and band heterotopia, unilateral and bilateral polymicrogyria, and focal cortical dysplasia. Functional magnetic resonance imaging was performed with finger tapping, somatosensory and visual stimulation, and language-related tasks.


RESULTS
We found activations within the dysplastic tissue in subcortical heterotopia, band heterotopia, and polymicrogyria, but not in periventricular heterotopic nodules. In one of the patients with focal cortical dysplasia, language-related activation involved part of the lesion. Functional reorganization beyond visible lesion boundaries was seen, with different patterns, in 4 patients.


CONCLUSIONS
In accordance with previous reports, our findings indicate that dysplastic neural tissue can be activated during task performance, and that in some patients, extensive functional reorganization occurs, highlighting the importance of functional magnetic resonance imaging in presurgical planning in those patients for whom epilepsy surgery is considered as an option.
Vitali
Paolo
P
Department of Clinical Neurophysiology, University of Genova, Genova, Italy. pvitali@istituto-besta.it
Minati
Ludovico
L
D'Incerti
Ludovico
L
Maccagnano
Elio
E
Mavilio
Nicola
N
Capello
Dario
D
Dylgjeri
Suela
S
Rodriguez
Guido
G
Franceschetti
Silvana
S
Spreafico
Roberto
R
Villani
Flavio
F
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000002:abnormalities* / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged