[Severe periodic hypokalemic paralysis. Prevention using beta-receptor blockade]

Area of Science:

• Endocrinology
• Neurology
• Cardiology

Background:

• This case study investigates a rare condition where severe physical exercise triggers recurrent paralysis attacks.
• The patient, a 24-year-old male, experienced frequent episodes of paresis, often with tetraplegia and occasional cardiac arrest.

Observation:

• Attacks were associated with a significant drop in serum potassium (hypokalemia) and a rise in intraleukocytic potassium.
• Elevated urinary catecholamine excretion (noradrenaline and adrenaline) was noted during emergency admissions.
• Intravenous adrenaline infusion during symptom-free intervals induced hypokalemia, which was prevented by propranolol, a nonselective beta blocker.

Findings:

• Adrenaline infusion caused a marked decrease in serum potassium without increased insulin excretion.
• Propranolol administration blocked the adrenaline-induced hypokalemia, suggesting a beta-adrenergic mechanism.
• Prophylactic oral propranolol therapy (120 mg/day) completely prevented exercise-induced paresis attacks.

Implications:

• This suggests a link between catecholamine surges, beta-adrenergic activity, and exercise-induced hypokalemic paralysis.
• Beta-blocker therapy may be a viable prophylactic treatment for similar cases.
• Understanding this mechanism could inform management strategies for exercise-induced autonomic dysfunction and electrolyte disturbances.