[A case of hereditary diffuse leukoencephalopathy with spheroids and pigmented glia presenting with long-term mild psychiatric symptoms].

A 64-year-old woman visited our hospital with early-onset dementia and progressive gait disturbance. She had demonstrated a mild communication disorder at the age of ~40 years; however, her psychiatric symptoms at that time were mild and were not accompanied by social problems. At the age of 59, she presented with memory loss, visual hallucinations, and delusions. Over the following five years she developed gait difficulties that gradually deteriorated and suffered frequent falls. On admission, neurological examinations revealed severe pyramidal and extrapyramidal signs of akinetic mutism. MRI of the brain showed cerebral atrophy, enlarged lateral ventricles, thinning of the corpus callosum, and leukoencephalopathy in the frontal-parietal lobes. Additionally, CT revealed a small spotty calcification in the frontal subcortical white matter. Genetic analysis revealed a single-base substitution (c.2330G>A/p.R777Q) in exon 18 of the colony stimulating factor 1 receptor (CSF1R) gene, encoding the CSF1R protein. She was diagnosed with hereditary diffuse leukoencephalopathy with spheroids (HDLS). HDLS is included in the differential diagnosis of early-onset dementia and should be considered in patients with mild personality change and abnormal behavior in the early course of the illness.