[Spectral analysis and EEG coherence in children with cerebral palsy: spastic diplegia].

Cerebral palsy (CP) occurs in 1.4-3.0 per 1000 live births children. Major clinical features of CP are: spasticity of extremities, extrapyramidale movements, dyskinesis and ataxia. Spastic diplegia is the most common type of CP. Spectral analysis and coherence EEG are noninvasive measures of the functional relationship between brain regions and are evaluated to determine electrophysiologic abnormalities of neurologic and psychiatric disorders. The objective of this study was to estimate EEG spectral power density and coherence in children with spastic diplegia. A group of 29 children (15 girls and 14 boys) with DS recruited from the Department and Clinic of the Pediatric Neurology Ward in Medical Academy in Białystok, were studied. Their ages ranged from 6-14 years, mean 8.79 +/- 3.23 years. EEG results were compared with a control group of 31 healthy children with normal EEG records. For every subject, 20 artifact-free EEG epochs, each 2 s duration were selected for spectral analysis and coherence functions. A standard (fast fourier transformation) algorithm of signal processing was used. Significant decrease of power alpha at occipital derivations demonstrated in children with DS. On the other hand, there was an increase of theta power and delta bands almost in all leads. An increase of beta power was no significant compared with controls. Significant decrease of interhemispheric coherence values in children with DS for the alpha and theta band frequencies and in a few cases decrease of delta and beta bands were observed. Differences of intrahemispheric coherence values were detected at central-temporal and temporal-occipital leads. The presented results support anatomic-neurophysiologic abnormalities demonstrated in children with DS.