title: Exploring dopaminergic activity in ring chromosome 20 syndrome: a SPECT study.
abstract: AIM: Several lines of evidence indicate that the dopaminergic system may play a role in the propagation of epileptic seizures and, indeed, DOPA metabolism impairment has recently been demonstrated in PET studies of ring chromosome 20 [r(20)] patients. We conducted a study looking for correlations between r(20) mosaicism, other clinical variables and both pre-synaptic dopamine transporter (DAT) expression and post-synaptic D2 receptor density. METHODS: Five patients with r(20) and epilepsy were enrolled in the study. DAT expression and D2 density were measured by single photon emission tomography (SPECT) imaging with 185 MBq of [123I]ioflupane and [123I]IBZM, respectively, on different days. Linear correlations between r(20) mosaicism, clinical variables and binding of [123I]ioflupane or [123I]IBZM were examined. RESULTS: A significant correlation between seizure frequency and r(20) mosaicism was detected (r=0.903, P<0.05), along with a negative correlation between r(20) mosaicism and binding of [123I]ioflupane in the putamen and in the caudate nucleus (r=-0.692 and r=-807; P<0.05). Seizure frequency was positively correlated with post-synaptic D2 density (r=0.925, P<0.05). CONCLUSION: Striatal neurons are involved in r(20) epilepsy; the relationship found between r(20) mosaicism and DAT expression suggests that drugs acting on the dopaminergic system could have a place in the treatment of this rare form of epilepsy.
authors.affiliation: Department of Biomedical Sciences and Technologies and Center of Molecular and Cellular Imaging (IMAGO), University of Milan, Milan, Italy - angelo.delsole@unimi.it.
authors.forename: A
authors.initials: A
authors.lastname: Del Sole
authors.forename: V
authors.initials: V
authors.lastname: Chiesa
authors.forename: G
authors.initials: G
authors.lastname: Lucignani
authors.forename: A
authors.initials: A
authors.lastname: Vignoli
authors.forename: L
authors.initials: L
authors.lastname: Giordano
authors.forename: M
authors.initials: M
authors.lastname: Lecchi
authors.forename: M P
authors.initials: MP
authors.lastname: Canevini