Positional ocular flutter and thickened optic nerves as sentinel signs of Krabbe disease.

A 5-month-old boy developed a large-amplitude, horizontal pendular flutterlike oscillation of the eyes, when placed in the supine position. Magnetic resonance imaging (MRI) 1 month earlier had shown isolated thickening of the optic nerves and chiasm without other central nervous system signal abnormalities. Repeat MRI at 5½ months of age showed a constellation of central nervous system signal abnormalities suggestive of Krabbe disease. The diagnosis was confirmed with serum enzymatic and genetic testing. This case demonstrates that positional ocular flutter can be a presenting sign of Krabbe disease and reinforces the observation that isolated thickening of the anterior visual pathways can antedate other central nervous system abnormalities on MRI.