Diffusion-Weighted and Conventional MR Imaging Findings of Neuroaxonal Dystrophy

BACKGROUND AND PURPOSE: Neuroaxonal dystrophy is a rare progressive disorder of childhood characterized by mental deterioration and seizures. The diffusion-weighted and conventional MR imaging findings are reported for six cases. METHODS: Six patients aged 19 months to 9 years with proved neuroaxonal dystrophy (one with the infantile form, five juvenile forms) underwent imaging at 1.5 T. Echo-planar diffusion-weighted images were acquired with a trace imaging sequence in five patients and with a three-gradient protocol (4000/110) in one. Images obtained with a b value of 1000 s/mm2 and corresponding apparent diffusion coefficient (ADC) maps were studied. ADCs from lesion sites and normal regions (pons and temporal and occipital lobes) were evaluated. RESULTS: A hyperintense cerebellum (a characteristic of the disease) was evident on fluid-attenuated inversion recovery images in all cases. Four patients had associated cerebral changes. Diffusion-weighted images, especially ADC maps, showed an elevated diffusion pat-tern in the cerebellum in the five juvenile cases (normal images at b 1000 s/mm2, ADCs of 1.30–2.60 103 mm2/s). A restricted diffusion pattern was evident in the infantile case (hyperintensity at b 1000 s/mm2, low ADCs of 0.44–0.55 103 mm2/s). ADCs were norma