PET evidence for a role of the basal ganglia in patients with ring chromosome 20 epilepsy.
BACKGROUND
Studies in animal models and epileptic patients have suggested that circuits of the basal ganglia may control epileptic seizures and that striatal dopaminergic transmission plays a key role in seizure interruption. Ring chromosome 20 (r[20]) epilepsy is a very homogenous type of epilepsy and is clinically characterized by long-lasting seizures suggesting a dysfunction in the seizure control system. The hypothesis that these long-lasting seizures are associated with a reduction of striatal dopamine was addressed in the present study in drug-resistant patients with r(20) epilepsy using PET.


METHODS
The authors performed [18F]fluoro-l-DOPA PET in 14 patients with r(20) epilepsy and compared uptake constants in the putamen and the caudate with those of 10 controls. In addition, the authors examined the correlation between these constants and the percentage of cells with r(20) mosaicism.


RESULTS
[18F]fluoro-l-DOPA uptake was significantly decreased bilaterally in the putamen and in the caudate nucleus of patients. This reduction was equal for both nuclei and was not correlated to the percentage of cells with r(20).


CONCLUSIONS
Striatal dopamine is modulated in r(20) epilepsy; dysfunction of this neurotransmission may impair the mechanisms that interrupt seizures.
Biraben
A
A
Service de Neurologie, CHU Pontchaillou, Rennes, France. arnaud.biraben@chu-rennes.fr
Semah
F
F
Ribeiro
M-J
MJ
Douaud
G
G
Remy
P
P
Depaulis
A
A
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology / Q000627:therapeutic use; D002421:Caudate Nucleus / Q000000981:diagnostic imaging* / Q000503:physiopathology; D025063:Chromosome Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002890:Chromosomes, Human, Pair 20 / Q000648:ultrastructure*; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004298:Dopamine / Q000502:physiology; D004351:Drug Resistance / Q000235:genetics; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging / Q000235:genetics / Q000503:physiopathology; D004827:Epilepsy / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology; D004829:Epilepsy, Generalized / Q000000981:diagnostic imaging / Q000235:genetics / Q000503:physiopathology; D004830:Epilepsy, Tonic-Clonic; D005239:Fear; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000000981:diagnostic imaging / Q000235:genetics / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D011699:Putamen / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012303:Ring Chromosomes; D013226:Status Epilepticus / Q000000981:diagnostic imaging / Q000235:genetics / Q000503:physiopathology; D009435:Synaptic Transmission
D000927:Anticonvulsants; D019275:Radiopharmaceuticals; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine; D004298:Dopamine