Serum prolactin and cortisol concentrations after grand mal seizures

SUMMARY Serial serum prolactin and cortisol levels were measured in five patients after a grand mal seizure and in four volunteers with simulated seizures. Single levels were measured after a witnessed seizure in 26 patients and in a matched control group. Significant increase in both pro-lactin and cortisol levels occurred after seizures. The change in cortisol level may reflect a non-specific stress response, but the increase in prolactin levels could not be accounted for on this basis, and probably indicates an alteration in hypothalamic neurotransmitter activity during the seizure. These findings may have clinical value in the diagnosis of epilepsy. Prolactin release from the anterior pituitary gland is thought to be controlled by release of neurotransmitter from the hypothalamus. In-hibition by dopamine ' is important but nor-adrenaline2 and gamma aminobutyric acid (GABA) ' may ailso inhibit prolactin release. The nature of the prolactin-releasing factor in mam-mals is uncertain, and the effect of 5-hydroxy-tryptamine (5-HT) on prolactin release in man is still unclear.46. Serum prolactin may, therefore, be considered as a peripheral marker of hypothalamic neuro-transmitter activity. Many other factors are known to influence prolactin secretion, including stress7 and drugs.8 Electroconvulsive therapy has been shown to produce a marked rise in serum prolactin,9 and in a recent uncontrolled study a significant increase in prolactin levels was found 20 minutes after a grand mal convulsion.10 Parox-ysmal discharges occur during grand mal seizures in major ascending and descending pathways concerned with consciousness and motor control, but involvement of the hypo-thalamus has not been studied. If a clearly defined rise in serum prolactin occurs after seizures this might have clinical applications in the assessment of patients with episodes of loss of consciousness of uncertain aetiology. As stres