Many studies have evaluated patients with idiopathic hypogonadothropic hypogonadotropism (IHH), but few of these studies utilize event-related potentials (P300).

To assess the cognitive functions of hypergonadotropic vs. hypogonadotropic patients.

The study group consisted of 41 untreated IHH patients, 32 untreated Klinefelter syndrome (KS) patients, and 30 healthy control subjects.

In this study, the latency and amplitude of P300 was evaluated in 41 untreated IHH and 32 untreated KS patients and compared to healthy control subjects (average age: 30 years). Also evaluated were the patients' hormone levels.

In this study, the amplitude of P300 was found to be reduced, and the latency prolonged in IHH patients in comparison to KS patients and control subjects. In KS patients, there was no difference in latency of P300, but the amplitude was reduced when compared with the control group. Cognitive dysfunction in patients with hypogonadotropism is related to androgen hormone levels. This deficiency can affect development of the central nervous system (CNS), causing defects of CNS to varying degrees during the perinatal period. Androgen deficiency is considered to exert its effects during the period of cognitive ability development, manifest in IHH patients but not KS patients.