Subacute sclerosing panencephalitis with pontine involvement.

In subacute sclerosing panencephalitis, brainstem involvement is rare. This paper reports an 11-year-old boy with the disease with prominent pontine involvement. Diffusion magnetic resonance imaging had superior information with respect to involvement of the nerve fibers. In the ventral part of the pons, the regions containing the longitudinal pontine nerve bundles were spared bilaterally and symmetrically. The pontine tegmentum was also spared. High signal in the affected regions was revealed by b = 1000 s/mm2 images. The apparent diffusion coefficient values in these regions were low, ranging between 0.43 x 10(-3) to 0.54 x 10(-3) mm2/s. Those of the spared tegmentum and longitudinal bundles were normal, ranging between 0.89 x 10(-3) to 1.04 x 10(-3) mm2/s, compared with the values from the normal-appearing regions of the cerebellar parenchyma.