Paroxysmal kinesigenic dyskinesias and pseudohypo-parathyroidism type Ib.

Pseudohypoparathyroidism is a rare cause of paroxysmal dyskinesias. We describe an otherwise well 10-year-old girl who was diagnosed with pseudohypoparathyroidism type Ib after presenting with involuntary movements of the hands and feet that occurred while running or walking. Magnetic resonance imaging of the brain indicated T(1) hyperintensities of the bilateral basal ganglia. A computed tomography scan of the head revealed diffuse cerebral calcifications, most prominent in the basal ganglia. Treatment with calcitriol and calcium carbonate led to a complete resolution of her signs. We recommend that hypoparathyroidism always be considered in patients with kinesigenic paroxysmal dyskinesias, especially insofar as it is a treatable disorder.