Bilateral substantia nigra involvement in vaccine-associated poliomyelitis

Abstract

Parkinsonism is a complication of some viral encephalitis,1 and poliovirus infection is a possible risk factor for late development of Parkinson disease (PD).2 There are several reports of PD arising in adults who had poliomyelitis (PM) as children,2 and pathologic specimens from fatal PM cases disclosed substantia nigra (SN) damage.3 In this setting, we report a child with vaccine-associated paralytic poliomyelitis (VAP-PM) presenting bilateral SN involvement on MRI. A 3-month-old boy came for evaluation 20 days after his first oral poliovirus vaccine (OPV) because of persistent fever, chills, and irritability. Over 5 days, he developed asymmetric lower limb weakness without discernible sensory loss. In the next week, his arms became weak, and poor suckling was noticed. Soon thereafter, frequent apneic episodes and somnolence appeared, and the child required ventilatory support. He was born healthy from cesarean section, and his mother denied any complication during pregnancy. His familial and past medical histories were otherwise unremarkable. On examination, …