SAP Multidisciplinary Open
Fahr's syndrome secondary to chronic hypoparathyroidism in a patient residing at high altitude
By Caleb Tenorio Meza, Weymar Lehi Poma Luna, Mauricio Paz del Rio and 5 others.
Abstract
Introduction
Fahr's syndrome refers to secondary forms of bilateral, symmetrical cerebral calcification, with hypoparathyroidism being the most common endocrine cause. Unlike primary familial cerebral calcification, the underlying disorder is correctable, giving the etiological diagnosis direct therapeutic significance.
Case report
A 61-year-old patient with a history of partial thyroidectomy and hypoparathyroidism (present for 25 years but managed without specialized follow-up) and a prior diagnosis of generalized epilepsy, chronic cor pulmonale, and recent pulmonary thromboembolism. The patient was admitted due to an acute exacerbation of chronic respiratory failure, presenting with a positive Trousseau sign, a QT interval of 609 ms, hypomagnesemia, hypokalemia, and metabolic alkalosis. PTH levels were < 3 pg/mL, and ionized calcium dropped to 0.54 mmol/L. A cranial CT scan revealed bilateral, symmetrical calcifications in the basal ganglia, dentate nuclei, frontoparietal white matter, and cerebellar hemispheres. Intravenous and oral calcium and magnesium replacement, combined with calcitriol and levothyroxine dosage adjustment, resolved the tetany and allowed for hospital discharge.