Cognitive Deficits and White Matter Alterations in Highly Trained Scuba Divers

Abstract

Nitrogen gas (N2), present in the normal atmospheric air, is a potential source of risk for scuba divers. It seems probable that myelin can represent, in hyperbaric conditions, a preferential site for the accumulation of N2 in central nervous system (CNS). The purpose of this study is to verify whether the practice of the scuba diving is capable to determine a damage of the brain white matter (WM) in a dose dependent manner and, consequently, possible deficiency of their cognitive abilities. For this purpose, 54 professional scuba divers (35 men and 19 women), with at least 2,000 dives in their careers, were studied. Possible alterations of brain WM were evaluated in terms of Fractional anisotropy (FA) by using Diffusion Tensor Imaging, whereas possible cognitive impairments were verified by means of neuropsychological testing, by studying: (1) General mental capability (2) Executive functioning; (3) Visuospatial construction such as Rey Complex Figure; (4) Attention and orientation: (5) Selective attention capacity and processing speed ability; (6) Memory. The results showed alteration of the WM in terms of changes in FA; these alterations, statistically significant but quantitatively quite modest, were mainly observed in the WM of the anterior part of the brain, whereas no differences were observed between left and right hemisphere. The alterations of the WM were associated with changes, also in this case statistically significant but quantitatively quite modest, of the cognitive functions, in particular of those dependent on the prefrontal cortex, such as attention and memory function. The present study leads to the conclusion that repeated dives, even performed in compliance with the current decompression tables, can progressively lead in the CNS to the formation of micro-lesions in the myelin sheet capable of altering the functioning of the neuron.

Attentive Processes and Blood Lactate in the Sambo

“…Being ready and vigilant in order to respond to an offense, to shoot for a basket, to go off to shoot, etc. in addition to specific muscle characteristics, can make a difference [17][18][19][20][21][22][23].…”

Executive Function among Chilean Shellfish Divers: A Cross-Sectional Study Considering Working and Health Conditions in Artisanal Fishing

“…As executive control might be involved in memory test results, this finding is in line with our result [ 13 ]. Studies on long-term effects on cognitive functioning of divers without a history of decompression illness further support that diving has negative long-term effects on the central nervous system [ 23 , 24 , 25 , 26 , 28 ]. As in our study, these studies did not find differences in the WCST perseverative responses between divers and less or unexposed comparison groups [ 23 , 26 ].…”

“…In recent decades, studies of cognitive function—including executive function—focused on assessing long-term effects of diving conditions on the central nervous system of divers with no history of decompression illness [ 23 ]. These studies showed poor performance on executive function tests by divers [ 24 ] compared to non-divers [ 25 , 26 ]. None of these studies were carried out in artisanal diving.…”

Executive Functions During Submaximal Exercises in Male Athletes: Role of Blood Lactate

“…cannot be excluded. However, since lactate receptors have been found in the brain (Morland et al, 2015), a role for lactate as a neural regulator could be proposed (see Proia et al, 2016;Coco et al, 2019a).…”