Hemispheric assymetry of abnormal focal EEG findingsTHESES
Hemispheric assymetry of abnormal focal EEG findings (Abstract)*. Theses. Recife, 2011
Fábio Galvão Dantas**
BACKGROUND: Left and right cerebral hemispheres are morphologically similar. Focal EEG abnormalities should appear with an equal frequency in both of them.
OBJECTIVE: To find out if there is an asymmetry for focal EEG abnormalities in a retrospective study of a series of EEGs.
METHOD: We retrospectively studied 10,408 EEGs from April 2001 to April 2010, separated by age and gender to estimate the frequency of left-sided versus right-sided focal abnormalities. Associated clinical features were also accessed.
RESULTS: Discharges were more prevalent in left cerebral hemisphere, in temporal lobe. A stronger lateralization was found among adults. Right-sided discharges occurred more in frontal lobe. Slow waves were more prevalent in left cerebral hemisphere and among adults. Among left-sided slow waves group, women were more prevalent and men, among right-sided group. Left-sided slow waves were more prevalent in temporal and parietal lobes and right-sided, in frontal and occipital lobes. Epilepsy occurred more in patients with focal discharges. Right-sided slow waves were more related to epilepsy and left-sided, to headache.
CONCLUSION: There were significant differences between cerebral hemispheres on focal EEG abnormalities, suggesting that cerebral asymmetry which must result from different specificities.
Key words: lateralization, EEG, sharp waves, slow waves.
