Bilateral Basal Ganglia Calcifications in a 61-Year-Old Woman With Normocalcemic Hyperparathyroidism.

Background/Objective: Bilateral basal ganglia calcifications are rare manifestations of neurodegenerative disorders associated with disturbances of brain calcium-phosphorus homeostasis. This report describes a patient with Fahr's syndrome secondary to normocalcemic primary hyperparathyroidism, a rarely reported entity that should be considered as a differential diagnosis. Case Report: A 61-year-old woman consulted the medical service stating: "I had a seizure and fell off my motorcycle." She reported experiencing syncope, vertigo, dizziness, dysarthria, limited lateral head movements, neck extension, and headache. These symptoms had been ongoing for a year. No significant medical history was identified, and no positive findings were noted on physical examination. Corrected serum calcium 9.83 mg/dL (8.6-10.3 mg/dL), parathyroid hormone 228.7 pg/mL (15-65 pg/mL), vitamin D 23 ng/mL (>20 ng/mL), thyroid-stimulating hormone 10.34 mU/L (0.4-4.5 mU/L), and free T4 0.81 ng/dL (0.8-1.9 ng/dL). A parathyroid ultrasound revealed 2 nodular images. Treatment with levetiracetam 500 mg every night was started. She currently experiences occasional episodes of vertigo and headache. Discussion: Fahr's syndrome is characterized by bilateral basal ganglia calcifications and has a multifactorial etiology. Differential diagnoses include infections and congenital disorders. In normocalcemic primary hyperparathyroidism, ectopic calcifications may arise from variations in serum calcium and reduced vitamin D production. Pharmacologic treatment focuses on managing neuropsychiatric symptoms, often involving anticonvulsants. Conclusion: Normocalcemic primary hyperparathyroidism is increasingly linked to Fahr's syndrome, highlighting the need to consider metabolic disorders despite normal calcium levels. Early diagnosis enhances targeted management, improving symptom control and quality of life.