Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Megalencephalic leukoencephalopathy with subcortical cysts (MLC), also known as van der Knaap disease, is an autosomal recessive leukoencephalopathy with MLC1 gene abnormalities. MLC is prevalent among Turkish people and the Agarwal ethnic group in the Asian-Indian community. Clinically, macrocephaly is seen during the first year of life, with progressive motor deterioration and cognitive decline. MRI shows diffuse hyperintensity of cerebral white matter on T2WI. The external and extreme capsules are prominently involved (arrows in B). Subcortical cysts are almost always present in the anterior temporal region (arrows in A) and are also frequently seen in frontoparietal region (yellow arrows in C). Gray matter is usually spared. Thick skull (white arrows in C) in the patient is due to chronic antiepileptic drug treatment. The differential diagnosis of MLC includes Canavan disease, Alexander disease, among others with megalencephaly.