title: Hyponatremia-associated cognitive impairment in traumatic brain injury.
abstract: The case of a traumatic brain injury (TBI) patient with dramatic cognitive deterioration in the absence of medical aetiology other than simultaneous decline in serum sodium led to an investigation of the association between declines in sodium levels and cognitive status. In a population of 50 persons undergoing TBI rehabilitation, 12 (24%) had relative (3 mEq/L) decreases in serum sodium while five (10%) experienced absolute hyponatremia (136 mEq/L). Correlation with cognitive status was significant when the absolute hyponatremia group was compared with those whose sodium levels remained above 136 mEq/L. A case-matched study of the relative hyponatremia group yielded no significant association between sodium-level decreases and cognitive status. These data support previous conclusions indicating wide variation in individual responses to changes in serum sodium. The threshold for significant effects of hyponatremia may be higher in patients with TBI than in populations studied previously.
authors.affiliation: Department of Rehabilitation Medicine, University of Kentucky College of Medicine, Lexington.
authors.forename: J W
authors.initials: JW
authors.lastname: Atchison
authors.forename: J
authors.initials: J
authors.lastname: Wachendorf
authors.forename: D
authors.initials: D
authors.lastname: Haddock
authors.forename: W J
authors.initials: WJ
authors.lastname: Mysiw
authors.forename: M
authors.initials: M
authors.lastname: Gribble
authors.forename: J D
authors.initials: JD
authors.lastname: Corrigan
mesh_terms: D001642:Bicycling / Q000293:injuries*; D001924:Brain Concussion / Q000097:blood / Q000150:complications; D003072:Cognition Disorders / Q000097:blood / Q000209:etiology*; D016489:Head Injuries, Closed / Q000097:blood / Q000150:complications*; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D019965:Neurocognitive Disorders / Q000097:blood / Q000209:etiology*; D009483:Neuropsychological Tests; D012964:Sodium / Q000097:blood
chemical_list: D012964:Sodium