Graves thyrotoxicosis frequently occurs after delivery through immune rebound mechanism. A 34 years old patient, in postpartum period was referred to rheumatologist for gradually gait impairment. Examination showed only weakness of pelvic girdle muscles which required an extensive differential diagnosis including: neurological diseases and inflammatory/metabolic/toxic myopathies. Routine lab tests were unremarkable except low cholesterol (128 mg/dl) and slightly increase of total alkaline phosphatase (ALP). Immunological and inflammatory tests were negative and muscle enzymes were within normal range. Three month later the patient had significant weight loss, persistent muscular symptoms and bright-eyed stare. On examination performed by the endocrinologist Graves disease was considered and confirmed by abnormal levels of TSH, FT4 and TRAb. The patient was treated with antithyroid drugs. After eight weeks muscular strength became nearly normal. FT4 was normal (14.4 pmol/l), but ALP level increased up to 3 times normal. Serum calcium and phosphorus were normal and so were the liver tests. Elevated ALP and osteocalcin levels were included in an accelerated bone turnover, which characterized hyperthyroidism.
Discussion: In women diagnosed with Graves disease during the ages of 20 to 35 years, 66% have a postpartum onset. The diagnosis is often quite simple, but it can be challenging when extrathyroidal manifestations occur early in the course of disease.