Clinical correlates of very fast beta activity in the EEG

Beta activity of 30-40 hz is rarely encountered, and has been reported to be more common in retarded individuals and those with psychiatric disorders. Of 3752 records in 1982-83, 0.8 percent demonstrated beta activity of 30 hz or faster, with a disproportionate representation of psychiatric symptoms and mental retardation in comparison with the general EEG referral population. No other specific correlations were evident, but the activity also occurred in neurologically and psychiatrically normal individuals. Although these findings may imply an association between very fast beta activity and psychiatric illness or mental subnormality, that association may be spurious or nonspecific in view of the small and heterogenous population demonstrating this type of beta activity. Controversy concerning very fast beta activity, as well as other infrequent or controversial patterns, may be lessened by application of spectral analysis and statistical techniques which are increasingly available for clinical EEG studies.