Hyponatremia in the intensive care unit: How to avoid a Zugzwang situation?

Table 1 Clinical signs of hyponatremic encephalopathy and osmotic demyelination

Hyponatremic encephalopathy^a	Central pontine myelinolysis	Extra-pontine myelinolysis
Mild hyponatremia	Suggestive features	Movement disorders
Mild neurocognitive impairment	Quadriparesis/plegia	Extra-pyramidal syndrome
Gait impairment	Ataxia	Dystonia
Moderate hyponatremia	Nystagmus	Choreoathetosis
Headaches	Dysarthria	Myoclonus
Nausea	Ophthalmoplegia	Opsoclonus
Emesis	Dysphagia	Akinetic-rigid state
Abdominal cramps	Pseudobulbar palsy	Akinetic mutism
Severe hyponatremia	“Locked-in” syndrome	Other symptoms
Restlessness	Associated neurological features	Emotional lability
Lethargy	Impaired consciousness	Depression
Confusion	Wernicke’s encephalopathy	Paranoia
Coma		Disinhibition
Seizure

^aNeurological manifestations according to the severity of hyponatremia which is itself correlated to the magnitude and the rapidity of the fall in PNa