title: α-[11C]-Methyl-L-tryptophan--PET in 191 patients with tuberous sclerosis complex.
abstract: OBJECTIVE
  This was an observational study done on a large cohort of patients with tuberous sclerosis complex (TSC) to determine whether i) the presence of α-[(11)C]-methyl-l-tryptophan (AMT) hotspots is related to the duration of seizure intractability, ii) the presence of AMT hotspots is related to specific TSC gene mutations, and iii) there is concordance between areas with an AMT hotspot and seizure lateralization/localization on scalp EEG.
  
  
  METHODS
  One hundred ninety-one patients (mean age: 6.7 years; median: 5 years; range: 3 months to 37 years) with TSC and intractable epilepsy were included. All patients underwent AMT-PET scan. AMT uptake in each tuber and normal-appearing cortex was measured and correlated with clinical, scalp EEG, and, if available, electrocorticographic data.
  
  
  RESULTS
  The longer the duration of seizure intractability, the greater the number of AMT hotspots (r = 0.2; p = 0.03). AMT hotspots were seen in both TSC1 and TSC2. There was excellent agreement in seizure focus lateralization between ictal scalp EEG and AMT-PET (Cohen κ 0.94) in 68 of 95 patients in whom both ictal video-EEG and AMT-PET showed lateralizing findings; in 28 of 68 patients (41%), AMT was more localizing. Furthermore, AMT-PET was localizing in 10 of 17 patients (58%) with nonlateralized ictal EEG.
  
  
  CONCLUSIONS
  AMT-PET, when used together with video-EEG, provides additional lateralization/localization data, regardless of TSC mutation. The duration of seizure intractability may predict the multiplicity of areas with AMT hotspots.
authors.affiliation: Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University School of Medicine, Detroit, MI, USA. hchugani@pet.wayne.edu
authors.forename: Harry T
authors.initials: HT
authors.lastname: Chugani
authors.forename: Aimee F
authors.initials: AF
authors.lastname: Luat
authors.forename: Ajay
authors.initials: A
authors.lastname: Kumar
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Govindan
authors.forename: Kathy
authors.initials: K
authors.lastname: Pawlik
authors.forename: Eishi
authors.initials: E
authors.lastname: Asano
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D014364:Tryptophan / Q000031:analogs & derivatives*; D014402:Tuberous Sclerosis / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; C028129:tryptophan methyl ester; D014364:Tryptophan