Gankam Kengne Fabrice
Nephrology Division, EpiCURA Hospital, Rue Maria Thomée 1, 7800 Ath, Belgium.
J Clin Med. 2023 Feb 21;12(5):1714. doi: 10.3390/jcm12051714.
Hyponatremia is the most common electrolyte disorder, occurring in up to 25% of hospitalized patients. Hypo-osmotic hyponatremia when severe and left untreated invariably results in cell swelling, which can lead to fatal consequences, especially in the central nervous system. The brain is particularly vulnerable to the consequences of decreased extracellular osmolarity; because of being encased in the rigid skull, it cannot withstand persistent swelling. Moreover, serum sodium is the major determinant of extracellular ionic balance, which in turn governs crucial brain functions such as the excitability of neurons. For these reasons, the human brain has developed specific ways to adapt to hyponatremia and prevent brain edema. On the other hand, it is well known that rapid correction of chronic and severe hyponatremia can lead to brain demyelination, a condition known as osmotic demyelination syndrome. In this paper, we will discuss the mechanisms of brain adaptation to acute and chronic hyponatremia and the neurological symptoms of these conditions as well as the pathophysiology and prevention of osmotic demyelination syndrome.
低钠血症是最常见的电解质紊乱，在高达25%的住院患者中出现。重度低渗性低钠血症若不治疗，必然会导致细胞肿胀，这可能会引发致命后果，尤其是在中枢神经系统。大脑对细胞外渗透压降低的后果特别敏感；由于被包裹在坚硬的颅骨内，它无法承受持续的肿胀。此外，血清钠是细胞外离子平衡的主要决定因素，而细胞外离子平衡又支配着诸如神经元兴奋性等关键的脑功能。出于这些原因，人类大脑已形成了适应低钠血症并预防脑水肿的特定方式。另一方面，众所周知快速纠正慢性重度低钠血症会导致脑脱髓鞘，即一种被称为渗透性脱髓鞘综合征的病症。在本文中，我们将讨论大脑适应急性和慢性低钠血症的机制、这些病症的神经症状以及渗透性脱髓鞘综合征的病理生理学和预防。
