Serial MRI findings paralleling the clinical deterioration of a year-old child with Krabbe disease are reported from the University of Rochester Medical Center, New York. At 13 months, an abnormal high signal on T2-weighted images in the frontoparietal white matter and cerebellar white matter was correlated with severe developmental delay, increased tone, and hyperextension (stage 2). At 32 months, MRI changes had progressed to include central and cortical atrophy, decreased white matter volume, thalamic and caudate atrophy, and abnormal high signal in all motor tracts except the anterior limb of the internal capsule. Clinically, the child was in stage 3, with spasticity of the upper extremities, peripheral neuropathy, and no response to auditory or visual stimuli. 
COMMENT. The 3-stages of Krabbe disease described by Hagberg begin with hyperirritability, restlessness, and frequent crying. Convulsions may develop, induced by sensory stimuli. Development becomes delayed, tone is increased, and later, reflexes are difficult to elicit and are absent in the lower limbs. Terminally, the infant is flaccid and blind. CSF protein is elevated and nerve conduction is delayed. The absence of the enzyme galactosyl ceramide B-galactosidase in leukocytes and skin fibroblasts is diagnostic, a test result common to all variants and stages of Krabbe disease, including antenatal.