title: Early in vivo MR spectroscopy findings in organophosphate-induced brain damage-potential biomarkers for short-term survival.
abstract: Organophosphates are highly toxic substances, which cause severe brain damage. The hallmark of the brain injury is major convulsions. The goal of this study was to assess the spatial and temporal MR changes in the brain of paraoxon intoxicated rats. T2-weighted MRI and ¹H-MR-spectroscopy were conducted before intoxication, 3 h, 24 h, and 8 days postintoxication. T2 prolongation mainly in the thalami and cortex was evident as early as 3 h after intoxication (4-6% increase in T2 values, P < 0.05). On spectroscopy, N-acetyl aspartate (NAA)/creatine and NAA/choline levels significantly decreased 3 h postintoxication (>20% decrease, P < 0.005), and 3 h lactate peak was evident in all intoxicated animals. On the 8th day, although very little T2 changes were evident, NAA/creatine and choline/creatine were significantly decreased (>15%, P < 0.05). Animals who succumbed had extensive cortical edema, significant higher lactate levels and a significant decrease in NAA/creatine and NAA/choline levels compared to animals which survived the experiment. Organophosphates-induced brain damage is obvious on MR data already 3 h postintoxication. In vivo spectroscopic changes are more sensitive for assessing long-term injury than T2-weighted MR imaging. Early spectroscopic findings might be used as biomarkers for the severity of the intoxication and might predict early survival.
authors.affiliation: Chemical, Biological and Nuclear Medicine Branch, Medical Corps, IDF, Tel-Hashomer Military Base, Israel. shaishrot@gmail.com
authors.forename: Shai
authors.initials: S
authors.lastname: Shrot
authors.forename: Debbie
authors.initials: D
authors.lastname: Anaby
authors.forename: Amir
authors.initials: A
authors.lastname: Krivoy
authors.forename: Igor
authors.initials: I
authors.lastname: Makarovsky
authors.forename: Yossi
authors.initials: Y
authors.lastname: Rosman
authors.forename: Eugenia
authors.initials: E
authors.lastname: Bloch-Shilderman
authors.forename: Shlomi
authors.initials: S
authors.lastname: Lazar
authors.forename: Amnon
authors.initials: A
authors.lastname: Bar-Shir
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
mesh_terms: D000465:Algorithms; D000818:Animals; D001930:Brain Injuries / Q000139:chemically induced / Q000175:diagnosis* / Q000378:metabolism*; D005240:Feasibility Studies; D007306:Insecticides / Q000633:toxicity; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D020258:Neurotoxicity Syndromes / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism*; D062025:Organophosphate Poisoning / Q000175:diagnosis* / Q000378:metabolism*; D010261:Paraoxon / Q000633:toxicity*; D011379:Prognosis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D016019:Survival Analysis
chemical_list: D007306:Insecticides; D010261:Paraoxon