A 58-year-old woman, a rural worker originally from Puebla, México. It presents confusion and disorientation that progresses to drowsiness in 2 weeks, being hospitalized with dehydration, lethargy (Glasgow Coma Score 10), increased myotatic reflexes, without meningeal data. Neck with goiter. It courses with polyuria. Simple CT imaging was normal. Serum calcium (albumin 1.9 g / dl) 15 meq/l, phosphorus 2.5 meq / l, with parathyroid hormone of 119 mg / ml. Ultrasound of neck was performed with a single thyroid nodule, with sponge-like pattern TIRADS 1, TSH 0.02 IU / ml, T4L 4.8 ng / ml. Zoledronic acid 4 mg, single dose and intensive hydration was indicated, with decrease in calcemia (9.5 meq / l) and total neurological recovery. Thyroid biopsy reports benign toxic adenoma, parathyroid with hyperplasia data. She withdrew to home with thiamazole, in current protocol for nodular resection.

The simultaneous thyroid and parathyroid dysfunction as causes of encephalopathy in the context of hypercalcemic crisis, constitute an unusual etiology.

The area of residence plays a fundamental role, due to its temperate climate with rainfall throughout the year (rainfall is decisive in the ecological cycle of iodine), at an altitude higher than 1500 m.a.s.l., it has been known for more than 50 years, as a goitrogenic area.
Timely treatment is critical for the control of neurological symptoms, on the other hand, although the extent and severity of endemic goitre have decreased in Mexico, it persists in communities that only consume what is produced in their lands, low in iodine.