Functional imaging in PNH caused by a new FilaminA mutation.

Abstract

Gray matter heterotopia can be divided into three categories based on the neuroanatomic distribution of misplaced neuronal precursor cells: periventricular (subependymal), subcortical, and band heterotopia (double cortex syndrome).1 In subcortical heterotopia, ectopic tissue extends in a curvilinear course from the ventricle wall to the cerebral cortex; in band heterotopia, the ectopic neurons form an additional band in the white matter, unable to reach their final destination, the neocortex. In periventricular nodular heterotopia (PNH), a subset of neurons does not leave the periventricular zone, indicating an earlier defect in migration macroscopically exhibiting nodules of neuronal tissue closely associated with the lateral ventricular wall. PNH is characterized by seizures and cardiovascular malformations in heterozygous females and prenatal death in most hemizygous males.2 Different mutations within the X-chromosomal FilaminA gene ( FLNA ) are associated with sporadic as well as familial forms of PNH.2,3⇓ FLNA encodes for a phosphoprotein regulating actin reorganization, which is required for the migration of neuronal precursor cells from the ventricle wall to the neocortex.2 Functional imaging using PET, SPECT, and fMRI are well established methods to evaluate the metabolic state, perfusion, and functional significance of heterotopic neuronal tissue in patients with intractable epilepsy prior to surgery. Previous studies using these imaging …