Increased Ipsilateral Striatal Serotonin Synthesis Following Frontal Cortical Resection in Children with Epilepsy.
Abstract number :
2.201
Submission category :
Year :
2001
Submission ID :
2309
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
H.T. Chugani, M.D., Pediatrics/Neurology/Radiology, Wayne State University, Detroit, MI; C. Juhasz, M.D., Pediatrics, Wayne State University, Detroit, MI; D.C. Chugani, Ph.D., Pediatrics/Radiology, Wayne State University, Detroit, MI; O. Muzik, Ph.D., Ped
RATIONALE: Following cortical resection during brain development, there is considerable reorganization of cortico-striatal projections both in humans and in a rat model (Chugani et al. Ann Neurol 1994;36:794-7; Kornblum et al. Brain Res Mol Brain Res 1994;21:107-14). Since serotonin release in striatum is modulated by cortico-striatal glutamatergic fibers, we used PET scanning with [alpha][11C]methyl-L-tryptophan (AMT) to evaluate postoperative changes of serotonin synthesis in the striata of children who had undergone cortical resection for intractable epilepsy, but who continued to have seizures.
METHODS: Nine children (age: 3.8-15.5 years, mean age 7.8[plusminus]3.6 years) underwent AMT PET scans 0.7 - 70 months after failed cortical resection for intractable epilepsy as part of their evaluation for further surgery. All 9 patients had undergone frontal resections (with additional resections in portions of temporal and parietal cortex in 7). These postoperative PET scans were compared to preoperative AMT PET of 8 children (age: 1.9 - 15.2 years, mean age 6.0[plusminus]4.1 years) with intractable epilepsy involving frontal lobe. In both groups, regions of interest were drawn on the striatum and thalamus bilaterally. AMT uptake of these structures ipsilateral to the epileptic focus was measured using an asymmetry index (AI%).
RESULTS: Postoperative AMT uptake was higher in the striatum ipsilateral to the resections in all 9 patients (AI%: 1.4 - 7.5%). Mean AI% on the postoperative PET scans was significantly higher than that on the preoperative AMT PET of the control group with epilepsy (p[lt]0.0001). Mean AI% in the thalamus was not significantly different between the two groups (p=0.27). Asymmetry of postoperative AMT uptake in the striatum showed a negative correlation with the duration between cortical resection and PET (Spearman[scquote]s rho= -0.68; p=0.042).
CONCLUSIONS: Increased ipsilateral striatal AMT uptake following cortical resection probably reflects increased serotonin synthesis due to disinhibition from severance of cortico-striatal projections which normally inhibit serotonin release. Our findings show that AMT PET is capable of detecting such changes in vivo. Furthermore, these changes appear to be specific and long-lasting, although they diminish with time.
Support: NS/RR 38324, NS 34488
Disclosure: Grant - NS/RR 38324, NS 34488