Hypokalaemic periodic paralysis





Epidemiology

  • Incidence: 0.10 cases per 100,000 person-years
  • Peak incidence: 6-15 years
  • Sex ratio: more common in males 3:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

Symptoms
  • Limb weakness (unilateral) (40%)
  • Arm weakness (unilateral) (40%)
Investigations
  • Hypokalaemia (85%): The potassium is typically low during attacks