Brain protection of nicergoline against hypoxia: EEG brain mapping and psychometry

Abstract

In a double-blind, placebo-controlled trial human brain function and mental performance as well as the antihypoxidotic properties of nicergoline were studied utilizing blood gas analysis, EEG brain mapping and psychometry. Hypoxic hypoxidosis was experimentally induced by a fixed gas combination of 9.8% oxygen (O2) and 90.2% nitrogen (N2) equivalent to 6,000 m altitude, which was inhaled for 23 min under normobaric conditions by 16 healthy volunteers. They received randomized after an adaptation session placebo, 10 mg, 30 mg and 60 mg nicergoline (NIC). Evaluation of blood gases, brain mapping and psychometry was carried out at 0, 2, 4, 6, 8 hrs oral drug administration. Blood gas analysis demonstrated a drop in PO2 from 95 to 35 and 34 mm Hg in the 14 and 23 min of inhalation, respectively. PCO2 decreased too (38 to 34 and 34 mm Hg), while pH increased (7.39 to 7.44 and 7.44). Base excess increased (-0.6 to 0.6 and 0.4) while standard bicarbonate decreased (24.4 to 24.1 and 23.8 mmol/l). Thus, blood gases remained stable between the 14 and 23 min of hypoxia during which time the neurophysiological and behavioral evaluations were carried out. EEG brain mapping exhibited an increase in delta/theta activity mostly over the parietal, temporal and central regions (left more than right), while alpha activity decreased (mostly over the parietal, central, frontal, fronto-temporal and temporo-occipital regions). 30 and 60 mg NIC attenuated this deterioration of vigilance. At the behavioral level, hypoxic hypoxidosis induced a deterioration of the noo- and thymospsyche which was mitigated by NIC. Based on 13 psychometric variables, the hypoxia-induced performance decrement was on the overall (2nd-8th hr) 43% after placebo as compared with pretreatment normoxic values, while only 29, 24 and 31% after 10, 30 and 60 mg nicergoline, respectively. The difference between placebo and the optimal dosage of nicergoline 30 mg reached the level of statistical significance (p less than 0.01, multiple Wilcoxon).

Exercise and DHA Prevent the Negative Effects of Hypoxia on EEG and Nerve Conduction Velocity

“…In contrast to our results, some previous studies showed that hypoxia caused an increase in delta activity (Burykh, 2005;Kraaier et al, 1988;Ozaki et al, 1995;Saletu et al, 1990;Schellart and Reits, 2001). The reason for this contradiction may be a few methodological differences among the studies.…”

“…Second, Saletu et al (1990) showed that a permanent effect occurred in the central nervous system by hypoxia at the altitude of 6000 m (19.685 ft) and there was no permanent effect at lower altitudes. In our study, the hypoxia level approximately corresponds to 3400 m (11.154 ft).…”

“…While EEG is an important indicator showing central nervous system functions, nerve conduction velocity (NCV) is a parameter that shows the PNS functions. In some previous studies, it was demonstrated that hypoxia increased the delta and theta activities (Kraaier et al, 1988;Saletu et al, 1990), but it reduced alpha activity (Kraaier et al, 1988;Saletu et al, 1990) and NCV (Carrington et al, 1994). In another study, it was reported that hypoxia reduced theta activity (Budzinska and Ilasz, 2007).…”

“…The reason for this contradiction may be a few methodological differences among the studies. First, severe and acute hypoxia exposure was applied in previous studies (Burykh, 2005;Kraaier et al, 1988;Ozaki et al, 1995;Saletu et al, 1990;Schellart and Reits, 2001). In our study, Po 2 values were measured as 55-56 mmHg.…”

“…Third, EEG was recorded during or immediately after the hypoxia exposure in previous studies (Burykh, 2005;Kraaier et al, 1988;Saletu et al, 1990;Schellart and Reits, 2001). However, in our study, EEG records were taken before and after the 28-day experimental period.…”