Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 40 4 2002 12 15 236 240 "Ashrafi MR Ghofrani M Ghojevand N " 2015 09 28 During two years study about mitochondrial disease (Sep 1999-Agu 2001), 15 cases of Leigh syndrome (LS) were diagnosed, that consisted of 11 boys and 4 girls aged between 6 to 156 (mean: 40.5) months. Most of the patients (46.7%) became symptomatic between 1-5 years of age. Triggering factors were reported in 66.6% of the patients and 40% of them became symptomatic after infections. The most frequent presenting symptoms of the patients were somnolence and lethargy (40%), developmental regression (20%) and seizure (13.3%). The most common neurologic findings were developmental regression or arrest (93.3%), seizure (93.3%) abnormal tone (86.7%) and abnormal movements (53.3%). Blood lactate increased in 93.3% and blood ammonia elevated in 26.7% of the cases. Symmetric striatal necrosis (100%) and caudate nucleus involvement (73.3%) were the most frequent neuroimaging findings of the patients. https://acta.tums.ac.ir/index.php/acta/article/view/2618 https://acta.tums.ac.ir/index.php/acta/article/download/2618/2600