Niemann-Pick disease type C (NP-C) is a rare autosomal recessive neurovisceral lysosomal lipid storage disorder. The clinical manifestations of the disorder are variable. This report describes the case of a 27-month-old girl with NP-C whose condition had been misdiagnosed as spastic cerebral palsy (CP). She had spasticity, particularly at both ankles, and gait disturbance. Magnetic resonance imaging of the brain revealed findings suspicious of sequelae from a previous insult, such as periventricular leukomalacia, leading to the diagnosis of CP. However, she had a history of hepatosplenomegaly when she was a fetus and her motor development had deteriorated, with symptoms of vertical supranuclear gaze palsy, cataplexy, and ataxia developing gradually. Therefore, NP-C was considered and confirmed with a genetic study, which showed mutation of the NPC1 gene. Thus, if a child with CP-like symptoms presents with a deteriorating course and NP-C-specific symptoms, NP-C should be cautiously considered.
Keywords: Cerebral palsy; Muscle spasticity; Niemann-Pick disease type C.