The Effects of Piracetam Upon Visual Event‐Related Potentials in Dyslexic Children

Abstract

Twenty‐nine dyslexic children (mean age 10 yrs) were randomly assigned to piracetam (3.3 gr/d) or matching placebo in a 36‐week double‐Mind study. Event‐related potentials (ERPs) were obtained at the end of treatment from a vigilance paradigm which required a response to letter‐matches or form‐matches. The drug group showed a significant advantage in letter‐bits compared with placebo, and a reduced variance in reaction time. The drug increased the amplitude of three factors from a principal components analysis of ERPs, and was interpreted as increasing a processing negativity when stimuli were letters. Effects upon the prestimulus baseline for letter‐hits were interpreted as faster termination of a CNV under drug for letter‐pairs. Latency of early N100 components were faster under drug, suggesting improved feature analysis. It is concluded that piracetam enhances feature analysis and increases attentional resources among dyslexics when the stimuli are recognized as having linguistic significance.

Double-Blind Placebo-Controlled, Neuropsychological and Neurophysiological Investigations with Oxiracetam (CGP 21690E) in Memory-Impaired Patients with Epilepsy

“…most improvement is found again for tests in which speed factors are predominant and for language (Picture Naming). These findings are more in agreement with the reports about piracetam-induced effects on ver bal processing [Conners and Reader, 1987;Wilsher, 1987] and with the studies that found primary effects on alertness and vigilance [Ashton. 1987;Wolkowitz et al.…”

“…Conners and Reader [1987] observed longer latencies of ERPs after 12 weeks but a greater variation of effects (such as a change of baseline negativity, in crease of N 100 and P456 positivity) after 32 weeks. If we disregard the 6-weeks findings, the oxiracetam group shows an increase of latency and decrease of amplitude, albeit not on a statistical significant level.…”

“…1987], The P300 has been proven a successful parameter for detecting neurophysiological correlates of drug-induced cognitive changes [Rosier et al. 1985] and has been extensively studied in the piracetam trial on dyslectics [Conners and Reader, 1987],…”

“…However, this may also have been caused by the localisation of our recordings (P3/PZ). Most effects of piracetam on P300 values were found for left-hemi sphere regions [Conners et al, 1984: Preston et al, 1974: Conners and Reader, 1987. As our interest was pri marily focused on memory and not on verbal processing, a non-lateralized localisation was chosen for our record ings.…”

“…1979;Simeon et al, 1980]. However, a multicentre study showed that, on the whole, the results were not convinc ing [Conners andReader. 1987: Wilsher, 1987], Im provement of the reading disability was found, but only in limited areas and most of the effects had to be charac terized as weak.…”