BMJ Case Reports 2009; doi:10.1136/bcr.07.2008.0577
  • Reminder of important clinical lesson

Recurring paralysis

  1. Hung-Wei Lin,
  2. Tom Chau,
  3. Chin-Sheng Lin,
  4. Shih-Hua Lin
  1. Tri-Service General Hospital, Department of Medicine, Number 325, Section 2, Cheng-Kung Road, Taipei, Neihu 114, Taiwan
  1. Shih-Hua Lin, shihhualin{at}
  • Published 17 March 2009


A 22-year-old Chinese man presented with sudden onset of generalised muscular weakness and paralysis upon awakening in the morning, due to sporadic periodic paralysis (SPP), a type of hypokalaemic periodic paralysis (HPP) without hyperthyroidism or familial history of paralysis. Laboratory studies showed marked hypokalaemia (K+ 1.6 mmol/litre). He received intravenous KCl supplementation at a rate of 0.14 mmol/kg/h and developed a paradoxical fall in serum K+ concentration from 1.6 to 1.4 mmol/litre during KCl therapy. After 160 mmol KCl supplementation his muscular strength recovered, but muscular paralysis recurred 2 h later. Acute recurrent hypokalaemia was the presumptive initial diagnosis and intravenous KCl supplementation was briefly reinitiated. Despite no obvious abnormalities on ECG monitoring, a 12-lead ECG clearly demonstrated tented T waves in the precordial leads suggestive of hyperkalaemia, later found to be 6.9 mmol/litre. After treatment with intravenous calcium gluconate, insulin and loop diuretics, his serum K+ concentration fell to 4.7 mmol/litre and muscular paralysis resolved in 3 h.


  • Competing interests: None.

  • Patient consent: Patient/guardian consent was obtained for publication.

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