Five new cases of a recently described leukoencephalopathy with high brain lactate

Background: A new leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate was recently defined. The authors describe five new patients with this entity. Methods: Brain MRI was performed in all patients and spinal MRI and proton magnetic resonance spectroscopy (H-1-MRS) in four patients. Laboratory examinations ruled out classic leukodystrophies. Results: MRI showed signal abnormalities in the periventricular and deep white matter, in the pyramidal tracts, mesencephalic trigeminal tracts, in the cerebellar connections, and in dorsal columns of the spinal cord. MRS showed decreased N-acetylaspartate and increased lactate in the white matter of all patients. In one patient choline-containing compounds were elevated. A slowly progressive sensory ataxia and tremor manifested at the age of 3 to 16 years and distal spasticity in adolescence. One 13-year-old patient was asymptomatic. Conclusions: A slowly progressive sensory ataxia is a typical feature in this new leukodystrophy. MRS favors a primary axonal degeneration.