Acute progression of neuromuscular findings in infantile Pompe disease.

A 2-year-old girl with Pompe disease developed an acute worsening of muscle weakness during a hospitalization, and required intubation for an upper respiratory infection. Electromyography and nerve conduction studies produced results consistent with a severe chronic motor axonal peripheral polyneuropathy, with no evidence of reinnervation. Magnetic resonance imaging of the brain demonstrated generalized hypomyelination and parenchymal volume loss, whereas magnetic resonance spectroscopy suggested neuronal injury and hypomyelination. This case provides compelling evidence for a slowly progressive neurodegenerative process in patients with infantile Pompe disease, affecting the motor neurons. Routine electromyography, nerve conduction studies, and cranial magnetic resonance imaging should be considered to delineate the presence of a neurodegenerative process in infantile-onset Pompe disease.