To understand the effects of cocaine on the cerebral cortex, 14 male polydrug abusers were enrolled in a study on the effects of cocaine on the electroencephalogram (EEG). The experimental treatments were placebo, 20 mg cocaine or 40 mg cocaine IV administered in a double blind, pseudorandom design. The EEG was recorded from 13 electrode positions over the left hemisphere during a 3-minute baseline recording and for 30 minutes after initiation of the IV injection. The spectral power for delta, theta, alpha and beta EEG bands was calculated KEY WORDS: Cocaine; EEG; Drug abuse Despite the epidemic of cocaine abuse during the past two decades, little is known about the neurophysiolog ical effects of this drug in humans. Berger, the frrst to study effects of cocaine on the human EEG, noted that 30 mg of subcutaneous cocaine increased EEG alpha abundance in two subjects (Berger 1931). Using an am plifter that allowed the recording of EEG in the beta fre quency range, he later observed an increase in EEG beta

Cocaine causes neuroendocrine aberrations in cocaine abusers with pituitary stress hormone secretion providing a window to the stress system in the brain. Substance abusers and control participants were hormonally profiled for 3 weeks. Abusers showed significant basal elevations in prolactin in week 1 with normalization over the 3 weeks. No differences in prolactin secretion were seen with either thyrotropin-releasing hormone stimulation or L-dopa suppression testing. Basal afternoon cortisol secretion was significantly elevated during weeks 1 and 2 comparing abusers to controls. Elevated afternoon cortisol secretion is a sensitive indicator of central stress activation. These results point to the hypothalamus, not the pituitary gland, as being primarily altered in cocaine withdrawal. The data demonstrate that both the dopamine-prolactin and hypothalamic-pituitary-adrenal (HPA) axes are affected during cocaine cessation. As medications are developed to modulate activation of a dysfunctional stress system, future therapeutic studies of substance abuse, withdrawal, craving and relapse should employ more sophisticated tests of hypothalamic pituitary function, especially the HPA axis, as this information may be a guide in the diagnosis and predict clinical responses.

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Atropine is an anticholinergic drug used in military medicine as an antidote following exposure to cholinesterase-inhibiting nerve agents. However, atropine causes neuropsychologic effects that impair performance. In the present study, we examined electrophysiologic indices that may accompany performance deficits. Quantitative electroencephalographic (EEG) analyses of changes induced by atropine (1.5, 3.0, and 6.0 mg/70 kg, intramuscularly) were assessed in seven male volunteers in a placebo-controlled, double-blind, cross-over experiment. Spontaneous EEG recordings were obtained from relaxed subjects before, 2 hours after, and 8 hours after atropine. Atropine significantly increased delta power, decreased alpha power, and tended to increase theta power and reduce beta and theta frequency. EEG indices of vigilance were reduced by the drug. Dose-related increases in sedation and dysphoria were obtained; some subjects liked these effects. Together, these findings confirmed that atropine causes dose- and time-related electrophysiologic and subjective effects that predict impaired performance.