Cortical blindness in acute carbon monoxide poisoning

A 3-year-old boy had persistent cortical blindness following acute carbon monoxide poisoning. He was believed to have suffered anoxic brain damage due to incomplete combustion of the briquette-type solid fuel. Computed tomographic (CT) scan of the brain and visual evoked potentials (VEP) in the early stage were normal. However, on the 20th hospital day CT scan showed leukomalacia and VEP showed an absence of N1-, and P1-waves which was well correlated with the clinical feature at that time.