Extensive intracranial calcifications and focal epilepsy as the initial manifestation of pseudohypoparathyroidism in a child: a case report

Abstract

Case Presentation: Pseudohypoparathyroidism is a rare endocrinopathy characterized by peripheral resistance to parathyroid hormone (PTH) action, resulting in hypocalcemia, hyperphosphatemia, and compensatory hormone elevation. Neurological manifestations may arise throughout the course of the disease, but an initial presentation with focal epilepsy associated with extensive intracranial calcifications in childhood is uncommon, representing a significant diagnostic challenge. This case highlights the role of neuroimaging in etiological investigation and the importance of early recognition of treatable metabolic causes of structural epilepsy. A 7-year-old female patient was referred for neurological evaluation due to monthly paroxysmal episodes that began at age 4 and progressively evolved into recurrent daily seizures. These were characterized by paresthesia, hypotonia, and weakness, alternately affecting the lower limbs, associated with reduced environmental contact, and lasting three to five minutes. During the first year of symptoms, the condition was initially attributed to an orthopedic cause, delaying neurological investigation. The patient presented significant impairment of neurocognitive development, remaining illiterate despite attending the 2nd grade of elementary school. On examination, she showed no evident phenotypic stigmata of Albright hereditary osteodystrophy, such as brachydactyly, early-onset obesity, or short stature, further hindering diagnostic suspicion. Discussion: Cranial CT revealed extensive calcifications involving the frontoparietal subcortical white matter, caudate nuclei, putamina, globus pallidus, left thalamus, and posterior cerebellar hemispheres — a pattern consistent with bilateral striatopallidodentate calcinosis with both supratentorial and infratentorial involvement. Electroencephalography showed predominantly focal epileptiform activity in the right posterior parietal regions, with contralateral spread.The combination of focal epilepsy, neurocognitive deficit, absence of the classic phenotype, and an unusual radiological pattern prompted a targeted investigation of calcium-phosphorus metabolism. Laboratory tests revealed marked hypocalcemia (5.58 mg/dL), hyperphosphatemia (9.4 mg/dL), and markedly elevated PTH (494 pg/mL), findings consistent with pseudohypoparathyroidism. Treatment with levetiracetam and calcium supplementation was initiated, with referral for joint follow-up with pediatric endocrinology. Final Comments: This case represents an unusual presentation of pseudohypoparathyroidism in childhood, in which long-standing focal epilepsy and extensive intracranial calcifications constituted the predominant manifestations, in the absence of the classic phenotypic features of Albright hereditary osteodystrophy. Neuroimaging plays a fundamental role in raising diagnostic suspicion, reinforcing that extensive calcifications involving the basal ganglia, thalamus, cerebellum, and white matter in children should prompt systematic investigation of calcium metabolism and PTH