Hyperthyroidism: an unusual case presentation.

Hyperthyroidism is the most common disorder of the thyroid. Patients typically present with complaints consistent with a hypermetabolic state, including nervousness, weight loss, heat intolerance, palpitations, irritability, and tremor. This case report reviews a 34-year-old woman who presented with unilateral upper extremity weakness, weight gain, and an episode of atrial fibrillation, the latter coinciding with a 36-hour lack of sleep and excess alcohol and caffeine intake. Although an extensive neurologic evaluation failed to identify any abnormality, the patient's laboratory analysis revealed elevations in thyroxine (T4) and triiodothyronine (T3) levels with unsuppressed thyroid-stimulating hormone levels. Subsequent treatment with the antithyroid drug methimazole (Tapazole) provided complete relief of symptoms. This case report illustrates how health care providers can be diverted to pursue a neurologic etiology when muscle weakness presents as a unilateral symptom. Plausible alternative causes for muscle weakness and other symptoms are presented.