The coming of magnetic resonance imaging (MRI) into clinical practice added advances in understanding the white matter diseases in children 1 . Previously, white matter and metabolic diseases were found to have a relatively specific pattern that could help in differential diagnosis, and primary defects in many inborn leukoencephalopathies have been elucidated including disorders from lysossomal storage, amino and organic acids, muscle and mitochondrial dysfunction 1,2 . Recent reports have described an apparently non-progressive condition characterized by severe psychomotor delay with variable degrees of tone and reflex abnormalities, normo-or microcephaly, and MRI findings consisting of bilateral anterior temporal cystic lesions with pericystic abnormal myelination and symmetric patchy lesions with increased signal in the frontal and occipital periventricular white matter regions 3 . Few patients with this condition have been described in literature [1][2][3][4] . In some aspects, this condition may resembles other leukoencephalopathies such as "megalencephalic leukoencephalopathy with subcortical cysts" and "leukoencephalopathy with vanishing white matter", due to the presence of subcortical cysts and white matter abnormalities, however, the clinical presentation and other neuroimaging features are distinct 3 . We describe the clinical, laboratory and neuroimaging characteristics of a patient with this rare entity.
CASEA one-year-old boy was born to healthy and non-consanguineous parents at 36 weeks of gestation. There was no family history of neurological diseases. Birth weight was 2,2 kg (25-50 th centile), length 45 cm (25-50 th centile) and head circumference 31 cm (below 5 th centile). Apgar indices were 6 and 9 (at one and ten min). Right after birth, he had transient respiratory discomfort and hypomagnesaemia with no further complications and he was discharged at the third day of life. It was already recorded that this child was hypotonic, with poor movements and adducted thumbs since the first weeks of life. He also presented a delay in neuropsychomotor acquisitions. The infant was admitted in our service at the age of 12 months. On examination he presented good overall condition with a head circumference of 44 cm (below 5 th centile). Neurological examination revealed a good contact with the examiner but he did not either fix on or catch an offered object. It was also observed increased limb muscle tone, brisk tendon reflexes in contrast with axial and apendicular hypotonia. Evaluation of cranial nerves was normal. Hematological tests and blood screening for metabolic diseases, including those for concentrations of very long-chain fatty acids, lactate and pyruvate, gave results in the normal ranges. Cerebrospinal fluid lactate concentration was normal. Serolog-