MRI Patterns of Leigh Syndrome

Abstract

To emphasize the varied clinical, neuroradiological and biochemical/genetic features of Leigh syndrome (LS). 3 cases with different metabolic anomalies and a family with 5 members affected by the same biochemical/genetic abnormality had 2 to 4 years follow-up with a 1.5 unit.

Cases 1 and 2 had respectively pyruvate dehydrogenase (PDH) and activated Complex I defect; both presented at birth with seizures and brainstem involvement and developed microcephaly and quadriparesis. MRI showed rapid, progressive cortical atrophy with transient subdural fluid collections (case 1), and haemorrhagic necrosis of both thalami and central mesencephalon (case 2). Case 3 started at the 5th month of life with seizures, hypotonia, brainstem signs, and was found to have a defect of Complex II of the mitochondrial respiratory chain; MRI disclosed transient subdural fluid collections, necrosis of the basal ganglia at first, and of brainstem and subcortical white matter soon afterwards. Of the five members of a family with the so called NARP mutation only two had symptoms of brain involvement: an infant who developed at four months of age hypotonia, epilepsy, mental/motor regression and retinitis pigmentosa, had MRI pictures of putaminal, cerebellar, brainstem necrosis along with hypomyelination of the cerebral hemispheric white matter. His aunt of 28 who, after presenting when 1 year old with a Lennox- Gastaut syndrome, suffered from mental delay, ataxia, pigmentary retinopathy, displayed a severe brain atrophy, mostly cerebellar, at MRI.

The peculiar variability of Leigh syndrome is stressed and confirmed, with emphasis on case 2.