Electrolyte Disorders and the Nervous System

ABSTRACT PURPOSE OF REVIEW This article provides an overview of the major electrolyte disorders and discusses in detail the homeostasis, etiologies, neurologic manifestations, and treatment of these disorders. RECENT FINDINGS The diagnosis and management of hyponatremia continue to evolve. Diagnostic accuracy is improved by assessing serum and urine osmolality as well as urinary sodium. Avoiding overcorrection of hyponatremia is crucial to avoid osmotic demyelination syndrome, although even careful correction can cause osmotic demyelination syndrome in patients who have other risk factors. The clinical presentation of osmotic demyelination syndrome has expanded, with many patients presenting with extrapontine myelinolysis in addition to central pontine myelinolysis. SUMMARY Electrolyte disorders often present with neurologic manifestations. Whereas disorders of some electrolytes, such as sodium, preferentially affect the central nervous system, disorders of others, such as potassium and calcium, have significant neuromuscular manifestations. An understanding of the pathophysiology of these disorders and recognition of these manifestations are crucial for the practicing neurologist as the symptoms are reversible with correct management.