[A case of L-2-hydroxyglutaric aciduria diagnosed with involuntary movements, in which improvement in motor symptoms was achieved following treatment].

A 49-year-old female presented with the primary complaint of hand tremors. Neurological examination on admission revealed signs of cognitive impairment, bulbar palsy, dystonia, cerebellar ataxia, and pyramidal tract disease. T₂-weighted brain MRI revealed hyperintense signals in the subcortical white matter, basal ganglia, and cerebellar dentate nucleus, with no atrophy of the brainstem or corpus callosum. Urinary organic acid analysis revealed elevated 2-hydroxyglutaric acid levels. Although the optical isomers could not be distinguished, L-2-hydroxyglutaric aciduria was diagnosed based on the disease course, symptoms, and characteristic MRI findings. The patient was started on riboflavin-enriched compounds and levocarnitine, resulting in an improvement in the Scale for the Assessment and Rating of Ataxia (SARA) score from 21 to 15 after six months. The case suggests that symptoms in adult patients who have not been treated for a long time can be improved by appropriate diagnosis based on neurological presentation, characteristic MRI findings, and intervention.