Electroencephalogram in Phenylketonuria

Kim, Sang Hyun; Suh, Eun Sook; Lee, Dong Hwan

Abstract

PURPOSE
Abnormal electroencephalogram patterns is common findings in patients with Phenylketonuria. This study was designed to determine the importance of an abnormal EEG and the relationships among EEG findings, biochemical and clnical patterns.
METHODS
We obtained EEG from 23 patients with PKU who had diagnosed and treated previously in Soonchunhyang University Hospital. And we analized EEG as aid in the evaluation of treatment in PKU, and determined relationship among EEG finding, Presence of convulsion, serum levels of phenylalanine, IQ level and DNA gene analysis.
RESULTS
The results were as follows;1) The male to female ratio was 1.3 : 1, and mean age was 4.3 years (between the age 3 days and 23 years) 2) The common clinical manifestations were musty odored urine (73/9%), mental retardation (65.2%), blond hair and fair skin (60.9%), convulsion (30.4%) and eczema (17.4%) in order. 3) Among 23 cases who was performed EEG, 12 cases (52.3%) showed abnormal pattern. And among 12 cases showed abnormal pattern, but only 5 cases had convulsion. 4) EEG abnormalities were high voltage slowing (5 cases), slow background activity (2 cases), focal spike-sharp wave (2 cases), multifocal spike (1 cases), hypsarrhythmia (1 cases). 5) Among 23 cases who was performed EEG, we obtained DNA molecular analysis in 10 cases, and EEG abnormalities were showed most commonly IVS4 (4 cases). 6) The mean IQ scores are low in abnormal EEG group compared with normal EEG group (37 : 67) 7) The mean serum levels of phenylalanine was 23.7mg/dL in abnormal EEG group, and 21.7mg/dL in normal EEG group. There is no significant correlation between blood phenylalanine level and EEG abnormalities.
CONCLUSIONS
Early detection and early treatment was most important in PKU. A goal of treatment is to eliminate neurologic sequale and development normal intellegence. The significance of abnormal EEG findings for decision in treatment and for the longterm prognosis of PKU children treated early remains obscure and further study is necessary.