Spectrum of neurological manifestations of idiopathic hypoparathyroidism and pseudohypoparathyroidism

We describe clinical, biochemical, radiological profile, and treatment outcome in 97 patients with idiopathic hypoparathyroidism seen over a period of 18 years. Of the 97 patients, 78 (80%) had idiopathic hypoparathyroidism and 19 (20%) had pseudohypoparathyroidism. The mean age±standard deviation (SD) at presentation was 28.7±14.1 years. There were 52 males, the mean lag time from first reported symptom to diagnosis was 5.9±5.2 years and the mean (±SD) follow-up was 1.8±0.4 years. The most common presenting manifestation was carpopedal spasm in 68 (70%) patients, followed by paresthesia and seizures in 52 (54%) patients. The mean (±SD) serum calcium and inorganic phosphate concentrations were 6.1±1.5 mg/dl and 6.3±1.5 mg/dl, respectively. The most common imaging abnormality noted was basal ganglia calcification followed by cerebral cortex and cerebellum calcification. More than one-third of patients were on various antiepileptic drugs including phenytoin. In addition to oral calcium and active vitamin D (calcitriol), twenty-six patients (27%) also required hydrochlorothiazide. The important finding in our study was long lag time from the first reported symptom to diagnosis. Phenytoin was the drug in almost one- third of our patients with seizures. Practicing clinicians should have high index of suspicion of diagnosis hypoparathyroidism in the appropriate clinical states to avoid the morbidity associated with hypoparathyroidism. Phenytoin should be avoided in patients with hypoparathyroidism and seizures.