Delayed dyskinesia and prolonged psychosis in a patient presenting with profound hyponatraemia

Abstract

SummaryA 65-year-old woman was admitted to the emergency unit with a 48 h history of generalised weakness and confusion. On examination, she had mild slurring of speech although there was no other focal neurological deficit. She had profound hyponatraemia (serum sodium level of 100 mmol/L) on admission with the rest of her metabolic parameters being within normal range. Subsequent investigations confirmed the diagnosis of small-cell lung cancer with paraneoplastic syndrome of inappropriate antidiuresis (SIAD). She was monitored closely in high-dependency unit with an attempt to cautiously correct her hyponatraemia to prevent sequelae associated with rapid correction. The patient developed prolonged psychosis (lasting over 2 weeks) and displayed delayed dyskinetic movements, even after a gradual increase in serum sodium levels close to 130 mmol/L. To our knowledge, delayed neurological recovery from profound hyponatraemia (without long-term neurological sequelae) has previously not been reported. This case should alert a clinician regarding the possibility of prolonged although reversible psychosis and dyskinetic movements in a patient presenting with profound symptomatic hyponatraemia.Learning points:Patients with profound hyponatraemia may develop altered sensorium, dyskinesia and psychotic behaviour.Full recovery from psychotic symptoms and dyskinesia may be delayed despite cautious correction of serum sodium levels.Careful and close monitoring of such patients can help avoid long-term neurological sequelae.

Treatment of Severe Hyponatremia

“…When symptoms first appear, restricted diffusion on MRI may be sensitive enough to detect lesions; however, the initial MRI is usually normal, and images become positive 1-3 weeks later (41). Both clinical and imaging findings are reversible, and some patients improve after a brief period of neurologic disability and never develop a positive MRI ( Figure 2) (42).…”

Osmotic Demyelination Syndrome following Correction of Hyponatremia by ≤10 mEq/L per Day

“…When hyponatremia develops more gradually, over 48 hours or longer, the brain adapts such that the brain cells restore its normal volume by loss of potassium within the first 3 hours, and then organic osmolytes including myo-inositol, glutamine, glutamate, taurine, glycine, aspartate and creatine. 8,9 When SNa falls below 105 mEq/L, survival is not possible without the adaptive loss of organic osmolytes. Overly rapid correction of chronic hyponatremia is known to cause ODS with its attendant neurologic manifestations which may be irreversible.…”

“…20 Thiamine supplementation, a low risk intervention, is advisable for any hyponatremic patient whose dietary intake has been poor. 29 Not mentioned by authors, presumably from a vasopressin-mediated process with reduced effective arterial blood volume 3% saline till SNa reached 120, then NS given de Souza et al 30 Vomiting from colchicine administration Not mentioned by authors John et al 8 SIAD secondary to small cell bronchogenic carcinoma of lung Saline infusion (not specified as 3%), discontinuation of thiazide diuretic Leens et al 31 Psychogenic polydipsia, thiazide diuretic use Water restriction, NS with potassium added Al-Shaibany et al 32 Watery diarrhea and vomiting 3% saline at 150 ml bolus, then NS 50-100 ml/h Silbert et al 33 Psychogenic polydipsia Hypertonic saline 2.5% and fluid restriction Reijnders et al 34 Thiazide diuretic use and poor intake Discontinuation of thiazide diuretic, isotonic saline infusion Malhotra et al 35 Excess fluid and low solute intake Fluid restriction Dellabarca et al 36 Not mentioned by authors, presumably from low solute intake Intravenous saline infusion (not specified as 3%), water restriction Yamada et al 19 Excess vasopressin stimulated by vomiting Continuous infusion of 3% saline at 25 ml/h Macmillan et al 4 Not mentioned by authors Desmopressin Dewitt et al 37 Not mentioned by authors Not mentioned…”

Nivolumab-induced endocrinopathy

“…1. Динамика изменения психического статуса на фоне коррекции гипонатриемии (адаптировано по [12]) Рис. 2.…”