Persistent diffusion abnormalities in the brain stem of three children with mitochondrial diseases

Abstract

We report 2 children (patients 1 and 2) with Kearns-Sayre syndrome and 1 (patient 3) with Leigh syndrome, who underwent serial diffusion-weighted MR imaging (DWI) studies for 2.8 (patient 1), 4.2 (patient 2), and 1.0 years (patient 3). The DWI revealed the persistent hyperintense signals in the pontine and mesencephalic tegmenta. The apparent diffusion coefficient in the affected regions remained constantly low, suggesting that cytotoxic edema and spongiform degenerations may compose these brain stem lesions.

Fig 1.

Selected T2-weighted images, DWI, and ADC maps of patient 1. The axial views of the T2-weighted image (TR/TE, 3203/96.0 ms) of patient 1 show the symmetric hyperintense lesions in the pontine tegmenta (A) and the bilateral basal ganglia (B) at 6 years of age. DWI (b = 1000 s/mm²) displays the hyperintense lesions of the pontine tegmenta at 6 years (C) and 8 years of age (E). The ADC map at 6 years (D) and 8 years of age (F) was obtained from the DWI (C and E). In panels A and C–F, the pontes are shown with higher magnification (insets). Arrows indicate the hyperintense lesions on T2-weighted images and DWI.

Fig 2.

Persistent diffusion abnormalities in the brain stem of patient 2. The axial views of the T2-weighted images (TR/TE, 2805/90.0 ms) of patient 2 at 9 months of age show hyperintense lesions in the pons (A) but not in the basal ganglia (B). In panels C–F, the DWI (C, and E) and ADC maps (D and F) at 9 months (C and D) and 4 years of age (E and F) are shown. The pontes are shown in insets of panels A and C–F with higher magnifications. Arrows indicate the abnormal signals on the T2-weighted images and DWIs.

Fig 3.

Persistent diffusion abnormalities in the brain stem of patient 3. The axial views of the T2-weighted images (TR/TE, 3156/90.0 ms) of patient 3 at 13 months of age demonstrate the symmetric hyperintense lesions in the mesencephalic tegmenta (A) but not in the basal ganglia (B). In panels C–F, the DWI (C and E) and ADC (D and F) maps at 13 months (C and D) and 2 years of age (E and F) are shown. The pontes are shown in insets of panels A and C–F with higher magnifications. Arrows indicate the abnormal signals on the T2-weighted images and DWIs.