Hyponatremia Should Be Added
We read the excellent review article (1) with great interest. We wish to add a further factor to the already explained causes of dizziness and unstable gait in old age: in our opinion, hyponatremia is a clinically relevant cause of unstable gait in older patients.
A recent prospective observational study from Switzerland showed that 31% of patients with severe hyponatremia <125 mmol/L experienced unstable gait (2).
Patients with mild chronic hyponatremia also fall notably more often than patients with normal serum sodium concentrations. Hyponatremia affects the gait pattern even more than a blood alcohol concentration of 0.6 g/L. However, an unstable gait is reversible by balancing out the hyponatremia (3). In a consecutive series over 15 months in 1659 patients at the geriatric hospital of the first author of this letter, a hyponatremia of <135 mmol/L was found in 30.0% of patients and one of <130 mmol/L in 10.1% of patients during the entire inpatient stay (authors’ own data). Older patients with hyponatremia are also more prone to developing ADH-induced osteoporosis and clinically relevant fractures (4).
Medication often plays a part; hyponatremia can develop during treatment with hydrochlorothiazide (HCT) and after consumption of medications affecting the central nervous system (antidepressants) and carbamazepine.
For this reason, the diagnostic evaluation of dizziness and unstable gait in old age should always include laboratory tests for electrolytes, so as not to overlook hyponatremia. It is likely that the number of falls could be reduced if our awareness of and attention towards hyponatremia in geriatric patients were to increase further.
Dr. med. Olaf Krause
Zentrum für Medizin im Alter
(sowie: Institut für Allgemeinmedizin, Medizinische Hochschule Hannover)
Prof. Dr. med. Johannes Hensen
KRH Klinikum Hannover Nordstadt
Conflict of interest statement
The authors have received honoraria for lectures on the subject of hyponatremia from Otsuka.
|1.||Jahn K, Kressig RW, Bridenbaugh SA, Brandt T, Schniepp R: Dizziness and unstable gait in old age—etiology, diagnosis and treatment. Dtsch Arztebl Int 2015; 112: 387–93 VOLLTEXT|
|2.||Nigro N, Winzeler B, Suter-Widmer I, et al.: Symptoms and characteristics of individuals with profound hyponatremia: A prospective multicenter observational study. J Am Geriatr Soc 2015; 63: 470–5 CrossRef MEDLINE|
|3.||Renneboog B, Musch W, Vandemergel X, Manto MU, Decaux G: Mild chronic hyponatremia is associated with falls, unsteadiness, and attention deficits. Am J Med 2006; 119: 71 e1–8.|
|4.||Ayus JC, Moritz ML: Bone disease as a new complication of hyponatremia: moving beyond brain injury. Clin J Am Soc Nephrol 2010; 5: 167–8 CrossRef MEDLINE|