Abstracts

The aim of our study was to establish the eletrencephalographic changes/ patterns found in children from Adrianopolis (Parana, Brazil) with abnormally high blood levels of lead, as a result of environment contamination from a local factory. We also tried to correlate eletrencephalographic (EEG) changes with factors related to variation of lead blood levels. Twenty children, range 2 to 14 years of age (mean 9,6 y/a), who suffered from chronic lead intoxication were studied. Blood lead levels were measured by atomic absorption spectroscopy and ranged from 20,1 to 35,8 mg/dL (mean 25,42 mg/dL). All subjects had an EEG recording and underwent either intelligence measurement or a more complete neuropsychological evaluation, depending on their age. Brain CAT scans and whole blood count (WBC) were also performed. EEG recording was standardized, with recordings samples of wakefulness, sleep (spontaneous or induced by chloral hydrate), photic stimulation and voluntary hyperventilation, if the subject was cooperative. All of the children had normal physical and neurological examinations and none of them had a history of seizures. Of the thirteen children who underwent neuropsychological testing, 6 had low range normal IQ and 7 had borderline for mental retardation results. Brain CAT scans were abnormal in only two subjects, both of which had parenquimal calcifications suggestive of neurocysticercosis. WBC disclosed anemia in 9 children. EEG evaluation failed to disclosed a specific pattern. However, 5 EEG recordings showed an irregular slow activity and in one of those epileptiform changes were also found. Statistical analysis (student[acute]s t test) showed no correlation between blood lead levels and abnormal EEG findings in either the normal or abnormal EEG groups There[rsquo]s no specific EEG pattern in those children who suffered chronic lead intoxication. Higher blood lead levels do not predispose to EEG abnormalities, even though such abnormalities were found in a proportion higher than that expected for age-matched controls.