Clinical features and recovery patterns of acquired non-thyrotoxic hypokalemic paralysis

Abstract

Objective To report the clinical features and recovery patterns of patients with non-thyrotoxic acquired hypokalemic paralysis. Methods The clinical and laboratory records of 11 consecutive patients with acquired non-thyrotoxic hypokalemic paralysis were reviewed and compared with those of 3 patients with thyrotoxic periodic paralysis (TPP). The causes of potassium wasting were diarrhea (n = 4), alcohol abuse (n = 2), pseudoaldosteronism (n = 2), primary aldosteronism (n = 1), distal renal tubular acidosis associated with Sjögren's syndrome (n = 1) and an unknown cause (n = 1). Results Three of the 11 patients had prominently asymmetric limb weakness, and 2 had predominant upper limb weakness. On admission, mean serum potassium and creatine kinase (CK) levels of patients with acquired hypokalemic paralysis on admission were 1.8 mEq/L and 4,075 U/mL, respectively, and the mean duration between admission and independent walking was 6.8 days (range, 2–31 days). Despite clinical recovery, 10 patients still presented with increased CK levels after several days (mean of maximum levels, 10,519 U/mL). In addition, normalization of serum potassium levels in patients with acquired hypokalemic paralysis patients was much slower compared to that in patients with TPP. One patient with acquired hypokalemic paralysis developed ventricular fibrillation, whereas all 3 patients with TPP had symmetric proximal and lower limb-dominant weakness and exhibited complete recovery from paralysis as well as normalized serum potassium levels within 24 h. Conclusions In patients with acquired non-thyrotoxic hypokalemic paralysis, asymmetric or upper limb-dominant weakness of the extremities is observed. Despite clinical improvement after treatment, normalization of serum potassium and CK levels is often delayed, and therefore, careful monitoring for cardiac and renal complications is required.