Hyponatremia-induced transient visual disturbances in acute spinal cord injury

Abstract

Study design: Case report and literature review. Objective: To report an unusual case of prolonged hyponatremia in acute cervical spinal cord injury complicated by visual disturbances and to review the literature regarding the issue. Settings: Spinal Cord Injury Unit in Go¨teborg, Sweden. Methods: Retrospective analysis of clinical charts of an individual with traumatic spinal cord injury. Results: A previously healthy 28-year-old man sustained a C7 injury in a motor vehicle accident. His injury was managed surgically and he was overhydrated during the acute management and postoperatively. When weaned off the respirator he was confused and anxious and showed a S-Na of 127 mmol/1 and complained of visual disturbances. The hyponatremia was treated by extra sodium and fluid restriction but fell to a lowest value of 121 mmol/l (Day 14 post injury). Visual acuity was 0.2 on right eye and 0.06 on left eye and the eye examination revealed signs of fundus hypertonicus. CT scans and MRI revealed no signs of brain edema. The patient was further treated by mineral corticoids and fluid restriction for 4 months and his vision improved slightly, but on a final examination 125 days post injury he was found to have an afferent pupillary defect on his left eye, and bilateral atrophy of the visual nerves. The hyponatremia resolved and 6 months post injury he showed a normal S-Na. Conclusions: SCI individuals are at increased risk of developing hyponatremia. The reported complication of visual disturbances further stresses the importance of prevention of overhydration and of timely management of hyponatremia in this group of patients.

Orthostatic hypotension following spinal cord injury: understanding clinical pathophysiology

“…25,74 Hyponatremia is also reported in acute SCI. 75 Thus, hyponatremia, probably secondary to supraphysiological ADH activity in SCI, 51 is common among acute and chronic SCI patients. 25,75,76 The combination of increased ADH secretion, low sodium intake, high sodium excretion and the resulting hyponatremia are likely to predispose towards small plasma volumes in SCI patients, and this, in turn, would exacerbate episodes of orthostatic hypotension in these individuals.…”

Challenges, concerns and common problems: physiological consequences of spinal cord injury and microgravity

“…32 In patients with chronic SCI, there is evidence of impaired water and sodium retention, which is confounded by limited salt and water intake. 33 There is only limited information available on circulating volume following SCI; however, it has also been shown that total blood volume and hemoglobin mass are decreased in individuals with SCI with a lesion above T4. 34 The combination of increased antidiuretic hormone secretion, low sodium intake, high sodium excretion and resultant hyponatremia are likely to predispose toward lower plasma volumes in patients with SCI.…”

Consequences of spinal cord injury on the sympathetic nervous system

“…A decrease in tear production can result in dry eye syndrome that can produce things like ocular surface damage (Dartt, 2004;Stern et al, 2004). Decreases in visual acuity have been shown post-SCI and is thought to be due to the increased risk of hyponatremia within the SCI population compared to able-bodied individuals (Barletta et al, 1994;Giordano et al, 2000;Karlsson and Krassioukov, 2004).…”