Periodic paralysis with normokalemia in a patient with hyperthyroidism: A case report

Rationale: Thyrotoxic periodic paralysis is characterized by a sudden onset of hypokalemia and paralysis. This condition mainly affects the lower extremities and is secondary to thyrotoxicosis. The underlying hyperthyroidism is often subtle without typical symptoms such as palpitations, tremors, anxiety, and weight loss; this causes a difficulty in early diagnosis. Here, we reported a case of periodic paralysis in a patient with hyperthyroidism whose potassium level was within the normal range. Patient concerns: A 33-year-old Taiwanese man presented to the emergency department with bilateral limb weakness (more severe in the lower limbs than in the upper limbs). On arrival, the patient's vital status was stable with clear consciousness. He denied experiencing recent trauma, back pain, chest pain, abdominal pain, headache or dizziness, or a fever episode. Physical examination showed no specific findings. Neurological examination showed weakness in the muscles of the bilateral upper and lower limbs. Muscle weakness was more severe in the proximal site than in the distal site. Diagnosis: Blood examination showed normal complete blood count, normal renal and liver function, and normal potassium (3.5 mmol/L, normal range 3.5–5.1 mmol/L), sodium, and calcium levels; however, the examination showed impaired thyroid function (thyroid stimulating hormone: 0.04 uIU/mL, normal range 0.34–5.60 uIU/mL; free T4: 1.96 ng/dL, normal range 0.61–1.12 ng/dL). Brain com...
Source: Medicine - Category: Internal Medicine Tags: Research Article: Clinical Case Report Source Type: research