Symmetrical central tegmental tract (CTT) hyperintense lesions on magnetic resonance imaging in children

Abstract

The central tegmental tract (CTT) is mainly the extrapyramidal tract connecting between the red nucleus and the inferior olivary nucleus. There are only a few case reports describing CTT abnormalities on magnetic resonance imaging (MRI) in children. Our purpose was to evaluate the frequency of CTT lesions and their characteristics on MRI, and to correlate the MR imaging findings with clinical features. We reviewed retrospectively the MR images of 392 children (215 boys and 177 girls) ranging in age from 1 to 6 years. To evaluate symmetrical CTT hyperintense lesions, we defined a CTT lesion as an area of bilateral symmetrical hyperintensity in the tegmentum pontis on both T2-weighted images and diffusion-weighted images in more than two slices. We measured the ADC (apparent diffusion coefficient) values of symmetrical CTT hyperintensity, and compared them with those of children without CTT abnormality. CTT lesions were detected in 20 (5.1%) of the 392 children. The mean ADC value for these 20 children was significantly lower than that of the normal CTT (p < 0.001). On MR imaging, other than CTT lesions, associated parenchymal lesion included: none (n = 6); other abnormalities, including periventricular leukomalacia (n = 3); thin corpus callosum (n = 3); ventricular dilatation (n = 2); encephalopathy (n = 2). Clinically, cerebral palsy was the most frequent clinical diagnosis (n = 6), accounting for 30%, which was significantly more frequent than the prevalence of cerebral palsy among children without CTT lesions (13%) (n < 0.05). CTT lesions were detected in 5.1% of all the children examined. Cerebral palsy was the most frequent clinical diagnosis.