Increased striatal serotonin synthesis following cortical resection in children with intractable epilepsy.
OBJECTIVE
Serotonin is a major regulator of structural brain plasticity, which may occur following cortical resection in humans. In this study we used positron emission tomography (PET) with alpha[11C]methyl-l-tryptophan (AMT) to evaluate serotonergic alterations in subcortical structures following cortical resection in children with intractable epilepsy.


METHODS
AMT uptake in the thalamus and lentiform nucleus was evaluated postoperatively (1-89 months following resection) in 19 children (mean age: 8.7 years) with a previous cortical resection due to intractable epilepsy. Ten children with partial epilepsy but without resection and seven normal children served as controls.


RESULTS
There was an increased AMT uptake in the lentiform nucleus ipsilateral to the resection as compared to the contralateral side (mean asymmetry: 4.2+/-3.0%), and the asymmetries were significantly higher than those measured in the control groups (p<or=0.001). Post-resection asymmetry indices in the lentiform nucleus correlated inversely with postoperative time (r=-0.67; p=0.002), but not with age (p=0.29) or the extent of resection (p=0.77). In contrast, thalamic AMT uptake asymmetries were not different among the three groups (p=0.63).


CONCLUSIONS
Cortical resection results in a sustained increase of AMT uptake in the lentiform nucleus, suggesting increased serotonin synthesis. Serotonergic activation in the deafferented striatum may play a role in the functional reorganization of cortico-striatal projections in humans.
Chugani
Harry T
HT
Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, MI, USA. hchugani@pet.wayne.edu
Juhász
Csaba
C
Chugani
Diane C
DC
Lawrenson
Lesley
L
Muzik
Otto
O
Chakraborty
Pulak K
PK
Sood
Sandeep
S
D000293:Adolescent; D000927:Anticonvulsants / Q000627:therapeutic use; D002540:Cerebral Cortex / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism; D004351:Drug Resistance; D004827:Epilepsy / Q000378:metabolism* / Q000601:surgery*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D019635:Neurosurgical Procedures; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012701:Serotonin / Q000096:biosynthesis*; D014364:Tryptophan / Q000031:analogs & derivatives
D000927:Anticonvulsants; D019275:Radiopharmaceuticals; D012701:Serotonin; D014364:Tryptophan; C525396:1-methyltryptophan