[MRI study of three siblings of suspicious Sjögren-Larsson syndrome].

We report the characteristics of high field magnetic resonance imaging (MRI) of three siblings with hereditary spastic paraplegia (HSP), probably of autosomal recessive inheritance. The proband was a 25-year-old woman who manifested slowly progressive spastic paraplegia, mental deficit, decayed teeth since her childhood. The siblings of the proband, 29-year-old woman and 27-year-old man, also showed the same clinical course as hers, and the symptoms are more severe in elder siblings. The proband solely had ichthyosis on her neck and lower thighs, which suggested Sjögren-Larsson syndrome. Sagittal and transverse slices of high field MRI (1.5T), T2-weighted (SE 2800/90) and T1-weighted (500/15) images were obtained. The cerebral atrophies were observed in the frontal and the parietal lobes, especially at the precentral and superior frontal gyri, whereas the occipital lobes were relatively spared. The atrophies of motor cortex seemed to be responsible for the disorder of voluntary movement. T2WI demonstrated a diffuse hyperintensity in the cerebral white matter, which suggested demyelination. T2WI also showed remarkable hypointensities in the globus pallidus, putamen, and thalamus. The degenerative involvement in these regions was also suspected. These abnormal intensities, both hyper- and hypo-intensities, were stronger in elder siblings, which indicated the intensity changes to be of progressive nature. Severe atrophy or hypoplasia of corpus callosum was also observed, however the cingulate gyri could be confirmed. We were not able to detect the callosal disconnection syndrome, because of their severe mental impairment. Spinal cord was slender and its degenerative changes were suggested. The high field MRI of a HSP family showed the extensive abnormal findings of the central nervous system in this HSP family, such as cerebral motor area, extrapyramidal system, corpus callosum, and spinal cord.