SUN-516 Fahr's Syndrome: A Rare Sequela of Hypoparathyroidism

Fahr’s syndrome (FS) is rare, progressive neurodegenerative disorder characterized by bilateral symmetric calcifications in the basal ganglia and cerebral cortex. Etiology of FS includes endocrine disorder, mitochondrial disease, dermatological or infectious disease. The prevalence of FS due to hypoparathyroidism (HP) is unknown. The presentation varies from movement disorders, pyramidal signs, neuropsychiatric manifestations to cognitive impairment. Case: We present a 46-year-old female with history of Grave’s disease s/p subtotal thyroidectomy, postsurgical HP and hypothyroidism for over two decades. She had history of chronic nonadherence with medications and clinic visits. Serum calcium levels were consistently below 7 mg/dl. She was found unresponsive and required intubation. Vital signs were within normal range. Physical examination except for neurological exam was unremarkable. Laboratory data: serum calcium- 6.2 mg/dl (8.4-10.2 mg/dl), ionized calcium- 0.77 mmol/L (1.13-1.32 mmol/L), phosphate - 6.4 mg/dl (2.7-4.5 mg/dl), 25 vitamin D- 21 ng/ml ( 30-100 ng/ml ), PTH- 7 pg/ml (15-65 pg/ml ), magnesium- 1.5 mg/dl (1.6-2.6 mg/dl ), creatinine - 5.16 mg/dl ( 0.4-1.1 mg/dl), WBC- 19.6 x 10(3)/ uL (4-10 x 10(3)/uL), TSH- 35 IU/ml (0.27-4.2 IU/ml), Free T4 – 0.96 ng/dl (0.9-1.7 ng/dl), lactate – 1.4 mmol/L (0.5 – 2.2 mmol/L). Urine toxicology was negative. EKG revealed prolonged QTc of 524 msec. Head CT showed no acute pathology however, revealed extensive bilateral calcifications of the dentate nuclei, basal ganglia, thalami and white matter, leading to consideration of FS. Calcium rose above 8 mg/dl with treatment (calcium gluconate infusion; oral calcium acetate and calcitriol via nasogastric tube). However, her mentation improved only after serum calcium remained above 8 mg/dl for the next five days. She regained consciousness and was oriented but mentation did not return to baseline. Conclusion: Although FS with extensive intracranial calcifications is a rare sequela of HP, HP is the most common cause of FS. The pathogenesis of these brain calcifications is not clear. Our patient had long standing HP and chronic non-adherence to medications. Her age at the time of diagnosis of FS rules out mitochondrial disorders. Her clinical presentation, extensive intracranial calcification with characteristic distribution and the absence of infection, dermatological lesions, traumatic or toxic causes or family history favor the diagnosis of FS. The progression of FS is thought to be associated with the calcium/phosphorus ratio, severity and duration of hypocalcemia. This emphasizes the importance of early stabilization of serum calcium level in HP to prevent development of complications. In most patients, clinical improvement and reversal of neuropsychiatric symptoms is notable after the correction of hypocalcemia. Hence, early recognition of HP as an etiology of FS is critical.