Non-specific leukodystrophy.: A new case of vacuolizing leukoencephalopathy with megalencephaly

Introduction. Amongst the conditions affecting the white matter, the disorders of myelinization, including the leukodystrophies, are important in the field of paediatric neurology. Although classically they have been classified according to whether the metabolic defect was known or not, at the present time great advances in neuroimaging have clarified many genetic disorders involving the white matter and new classifications have been devised. The group of unknown aetiology includes the so-called nonspecific leukodystrophies, characterized by their onset in infancy with a usually more moderate clinical course, and neuro-imaging (computerized tomography-CT-magnetic resonance-MR-) with alteration of the signal from the white matter which is symmetrical, bilateral and diffuse. Study and investigation of the patterns of MR has permitted isolation of two new clinical conditions of the nonspecific leukodystrophies group: leukodystrophy with megalencephaly and temporal cysts (Van der Knaap, 1995)for which currently the term vacuolizing leukoencephalopathy with megalencephaly is preferred and the CASH syndrome (childhood ataxia with central hypomyelinization or vanishing white matter disease) (Van der Knaap, 1997). We present a review of nine cases of non-specific leukodystrophies with an average course of 13 years. They were studied using the protocol of the European working party on demyelinating diseases. One of these fulfilled clinical and radiological criteria for the diagnosis of vacuolizing leukoencephalopathy with megalencephayl: onset in early childhood, macrocephaly, normal metabolic studies, moderate progression and alteration of the white matter signal which was bilateral, symmetrical and diffuse with the presence of oedema and temporal subcortical cysts. We discuss the most relevant articles currently published on this condition.