Spectrum of hypokalaemic periodic paralysis in a tertiary care centre in India.

Background: Acute flaccid paralysis is a common neurological emergency with diverse causes and variable outcome. There is a paucity of reports documenting the spectrum of hypokalaemic paralysis in neurological practice.

Objective: To report the clinical features, aetiology, and outcome of patients with hypokalaemic paralysis in a tertiary care teaching hospital in India.

Methods: Consecutive patients with acute flaccid paralysis with hypokalaemia from 2008 to 2010 were included in the study. Patients with Guillain-Barré syndrome, porphyria, polio and non-polio enterovirus infection and myositis were excluded. Detailed clinical examination, urinalysis, renal function tests, arterial blood gas analysis, thyroid hormones, and electrocardiogram were carried out. Patients received intravenous or oral potassium supplementation and their underlying causes were treated.

Results: Thirty patients aged 17-52 years, including three females, were included. Secondary causes of hypokalaemic paralysis were present in 13 patients and included thyrotoxic paralysis in five and renal tubular acidosis (RTA) and Gitelman syndrome in four each. All the patients had quadriparesis and 10 had severe weakness (MRC grade <2). Tendon reflexes were reduced in eight and brisk in four patients. Respiratory paralysis was present in six patients and one needed artificial ventilation. Fifteen patients had severe hypokalaemia (<2 mmol/l), four had acidosis, and six had alkalosis. The secondary group had more severe hypokalaemia and needed longer time to recover.

Conclusion: 43.3% of patients with hypokalaemic paralysis had a secondary cause for their condition. Patients with severe hypokalaemia with acidosis or alkalosis should be investigated for secondary causes as their management differ.