Thyrotoxic Periodic Paralysis in a Turkish Male; The Recurrence of the Attack after Radioiodine Treatment

Abstract

Abstract. Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare complication of hyperthyroidism and an uncommon form of hypokalemic periodic paralysis. Its differentiation of more common forms of periodic paralysis is important because aggressive treatment can place the patient at risk for rebound hyperkalemia. Treatment of the underlying thyroid dysfunction cures the muscle symptoms. Here we describe a 37-year-old Turkish male with THPP whose paralysis attack recurred soon after administration of radioactive iodine. THYROTOXIC hypokalemic periodic paralysis (THPP) is a rare complication of hyperthyroidism in the Western population. It occurs primarily in males of Asian descent, including patients of Japanese, Chinese, Vietnamese, Korean, Filipino, American Indian, and Hispanic ancestry [1][2][3][4][5][6][7][8][9][10]. Although the association of thyrotoxicosis and periodic paralysis has been wellknown since 1931 [11] it is not reported from Turkey in English literature, most probably because of unfamiliarity with the disorder. We herein report a 37-year-old Turkish male patient with THPP who also experienced a paralysis attack ten days after the administration of radioiodine despite the treatment with propranolol. Case reportA 37-year-old Turkish male patient presented with the complaint of approximately ten episodes of muscle weakness for 2 years. These attacks occurred in all but one episode at night, following exertion or consumption of large carbohydrate meals. He was usually awakened from sleep in the early hours with difficulty of ambulation due to muscle weakness of extremities mainly in his legs. There were no prodromal symptom and no seasonal variation of the attacks. The duration of paralysis attacks ranged from four to 24 hours. He didn't seek medical attention for the paralysis attacks and they all resolved spontaneously. There was no family history of neuromuscular and endocrine abnormality.He was diagnosed as having hyperthyroidism based on the clinical symptoms of occasional palpitation and nervousness and the suppressed thyroid stimulating hormone (TSH) of 0.01 mU/mL (normal, 0.35-4.5 mU/ mL) five months ago. Then he was put on carbimazole therapy (20 mg daily). After the cessation of therapy by his own decision approximately one month ago, he experienced another attack. He denied any weight loss, heat intolerance, or diarrhea. The physical examination including muscle strength and tendon reflexes was unremarkable.His free thyroxine (FT 4 ) level was 5.26 ng/dL (normal, 0.8-1.9 ng/dL) and TSH level was <0.002 mU/mL (normal, 0.4-5.0 mU/mL). The TSH-receptor-stimulating antibody level was 135 U/L (normal, 0-9 U/L). Thyroid scan revealed diffuse uptake in a normal sized gland with a 24-hour radioactive iodine uptake of 52.1%. These findings were found to be most con-

Thyrotoxic Periodic Paralysis: Eight Cases in Males of Hispanic Origin from a Single Hospital

“…TPP has also been report-ed after treatment for hyperthyroidism, up to 5 weeks after medications were initiated (2), and even post-RAI therapy (9). In one case series, only 29% of patients had previous history of thyrotoxicosis, while 60% had clinical evidence of thyrotoxicosis at initial presentation (2).…”

“…Higher doses of RAI may be needed, since lower doses have shown a lower remission rate (28.6%) and a longer time to remission (20). RAI only rarely precipitates a TPP episode but can be associated with transient thyroiditis and hyperthyroidism (9).…”

Hypokalemic Periodic Paralysis Due To Distal Renal Tubular Acidosis

“…Hypokalemia may be secondary to potassium deficit as well as abnormal intracellular potassium shift. It may be familial or sporadic (3)(4)(5)(6)(7)(8). The familial form is more common in Western societies, while sporadic disease is more prevalent in Asian countries.…”

Thyrotoxic Periodic Paralysis

“…The report by Akar et al [1] regarding hypokalaemic thyrotoxic periodic paralysis (HTPP) in a Turkish male is a timely reminder for the practising physicians about this interesting condition. This condition is both frightening to the patients and perplexing to the doctors.…”