PURPOSE: In patients with hippocampal sclerosis (HS), anterior temporal lobe resection offers the possibility of a long-lasting suppression of seizures in two thirds of patients. White matter (WM) [11C]flumazenil volume of distribution (FMZ-Vd) reflects the number of neuronal cell bodies in WM. Our objective was to correlate WM FMZ-Vd in patients with unilateral HS and postsurgical outcome. METHODS: We performed [11C]FMZ-PET in 15 patients with refractory mesial temporal lobe epilepsy (mTLE) and a quantitative MRI diagnosis of unilateral HS subsequently histologically verified in all cases. Median follow-up was 7 years (range, 6-9 years). Metabolite-corrected arterial plasma input functions and spectral analysis were used to generate parametric images of [11C]FMZ-Vd. Statistical parametric mapping (SPM99) with explicit masking was used to investigate the entire brain volume including WM. RESULTS: Eight patients had Engel class IA outcome (completely seizure free since surgery), and seven were not seizure free. Comparison of seizure-free patients with those who continued to have seizures after surgery revealed areas of increased FMZ binding around the posterior horns of the ipsilateral (z=3.7) and contralateral (z=2.7) ventricles in those with suboptimal outcomes. CONCLUSIONS: Preoperative [11C]FMZ-PET can detect periventricular increases of WM FMZ binding, implying heterotopic neurons in WM, in patients with mTLE. The presence of such increases correlates with a poorer outcome.
PURPOSE: In patients with hippocampal sclerosis (HS), anterior temporal lobe resection offers the possibility of a long-lasting suppression of seizures in two thirds of patients. White matter (WM) [11C]flumazenil volume of distribution (FMZ-Vd) reflects the number of neuronal cell bodies in WM. Our objective was to correlate WM FMZ-Vd in patients with unilateral HS and postsurgical outcome. METHODS: We performed [11C]FMZ-PET in 15 patients with refractory mesial temporal lobe epilepsy (mTLE) and a quantitative MRI diagnosis of unilateral HS subsequently histologically verified in all cases. Median follow-up was 7 years (range, 6-9 years). Metabolite-corrected arterial plasma input functions and spectral analysis were used to generate parametric images of [11C]FMZ-Vd. Statistical parametric mapping (SPM99) with explicit masking was used to investigate the entire brain volume including WM. RESULTS: Eight patients had Engel class IA outcome (completely seizure free since surgery), and seven were not seizure free. Comparison of seizure-free patients with those who continued to have seizures after surgery revealed areas of increased FMZ binding around the posterior horns of the ipsilateral (z=3.7) and contralateral (z=2.7) ventricles in those with suboptimal outcomes. CONCLUSIONS: Preoperative [11C]FMZ-PET can detect periventricular increases of WM FMZ binding, implying heterotopic neurons in WM, in patients with mTLE. The presence of such increases correlates with a poorer outcome.
Authors: William H Theodore; Ashley R Martinez; Omar I Khan; Clarissa J Liew; Sungyoung Auh; Irene M Dustin; John Heiss; Susumu Sato Journal: J Nucl Med Date: 2012-07-10 Impact factor: 10.057
Authors: H Laufs; M P Richardson; A Salek-Haddadi; C Vollmar; J S Duncan; K Gale; L Lemieux; W Löscher; M J Koepp Journal: Neurology Date: 2011-08-17 Impact factor: 9.910