Thyrotoxic periodic paralysis - a retrospective study from Southern India

Area of Science:

• Endocrinology
• Neurology

Background:

• Thyrotoxic periodic paralysis (TPP) is an uncommon but serious complication of thyrotoxicosis.
• It presents as episodes of acute flaccid paralysis, primarily affecting males of Asian descent.
• Understanding its clinical and biochemical profile is crucial for timely diagnosis and management.

Purpose of the Study:

• To describe the clinical and biochemical features of thyrotoxic periodic paralysis.
• To evaluate treatment outcomes in a cohort of Indian patients.
• To compare patients with TPP to those with thyrotoxicosis without paralysis.

Main Methods:

• A retrospective study conducted at a tertiary care center in southern India.
• Compared patients with TPP (cases) to patients with thyrotoxicosis but no paralysis (controls).
• Collected data on clinical presentation, biochemical parameters, and treatment received.

Main Results:

• The study included 41 cases and controls, with a high male proportion (92.6%) in the TPP group.
• Patients with TPP had significantly lower mean serum potassium, free T4, total T4, and total T3 levels compared to controls.
• Graves' disease was the predominant cause of thyrotoxicosis in both groups; goitre was less common in TPP cases.

Conclusions:

• This study represents one of the largest series of TPP cases in India.
• Significantly lower serum potassium and thyroid hormone levels are observed in thyrotoxic patients with periodic paralysis.
• Two cases suggested a potential co-existing Gitelman's syndrome contributing to hypokalemia.