Endocrine Abstracts

Background: Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare complication of hyperthyroidism, primarily reported in Asian populations, affecting about 2% of hyperthyroid individuals. In non-Asian populations, its incidence is considerably lower, estimated at 0.1% to 0.2%. THPP typically presents with muscle weakness and hypokalemia, predominantly in males aged 20 to 40.

Case Presentation: We describe a 38-year-old male patient of African descent who presented to the Accident and Emergency department with progressive weakness of the lower limbs, which subsequently affected his upper limbs. Neurological examination revealed diminished reflexes in the lower limbs, while reflexes in the upper limbs were normal, with no other neurological deficits observed.

Investigations: Laboratory tests indicated a critically low serum potassium level of 2.2 mmol/l, signifying severe hypokalaemia. Thyroid function tests showed undetectable thyroid-stimulating hormone (TSH), elevated free thyroxine (T4) at 30 pmol/l, and undetectable high free triiodothyronine (T3). Diffuse thyroid enlargement was noted, prompting further evaluation for autoimmune thyroiditis, Grave’s thyrotoxicosis with thyroid antibody testing pending.

Discussion: This case illustrates the atypical presentation of THPP in a non-Asian patient and emphasizes the importance of timely diagnosis. The combination of acute muscle weakness and specific laboratory findings should prompt clinicians to consider THPP in hyperthyroid patients, particularly in the context of acute paralysis. This is a condition which can cause significant morbidity with muscular paralysis and respiratory arrest secondary to respiratory muscular paralysis. Our patient did not have any reparatory issue on admission. He was treated with antithyroid medications, betablockers and Potassium.

Conclusion: The rarity of THPP in non-Asian populations highlights the need for increased awareness among healthcare providers. Prompt recognition and management of this condition can improve patient outcomes and prevent complications related to hypokalemia and thyroid dysfunction. Further research is needed to enhance understanding and treatment strategies for THPP across diverse populations.