Analysis of Clinical and Metabolic Profile of Acute Neuromuscular Weakness Related to Hypokalemia.

Objective: Acute neuromuscular weakness related to hypokalemia is a readily treatable disorder associated with diverse aetiologies. In this study we aim to report clinical pattern and biochemical features to identify the different aetiologies of the hypokalemic neuromuscular weakness.

Methods: Retrospective reviews of the medical record were analysed. Evaluation included demography, clinical features, investigations performed to ascertain the aetiologies. All the patients were categorised in to 3 groups; Idiopathic hypokalemic paralysis (IHP), dengue associated hypokalemic paralysis (DHP) and secondary group (SG) which included renal tubular acidosis (RTA- 1 and 2), thyrotoxic periodic paralysis (TPP) and Gitelman's syndrome (GS).

Results: Forty patients were analysed and the mean age was 31.78 (range, 14-60) years and 35 (87.5%) were male.The underlying aetiologies comprised of IHP in 20, DHP in 12, RTA-2 in 4, RTA-1 in 2, TPP, GS in one each. Weakness on Medical Research Council (MRC) grade was 2.6±1.19 (range 0-4). Comparison of various clinical and laboratory parameters revealed that more patient in IHP and SG had recurrent attack (p=0.001). DHP group had low platelet (p=0.001), high creatine phosphokinase (CPK) (p=0.01) and serum glutamic oxaloacetic transaminase (SGOT) (p=0.008). SG had significantly lower serum potassium (p=0.04) and more time to improve (p=0.02). Recovery time correlated negatively with serum potassium (r=-0.44, p=0.004) and grade of weakness (r= 0.42,p=0.007).

Conclusion: In half of the patients, secondary causes were identified. After IHP, the DHP emerged as second common cause in post monsoon season. SG had significantly lower serum potassium, recurrent attack and more time to improve.