Neurofibromatosis 1 is also known as Von Reckhlinghausen disease. It is due to mutation on chromosome 17. The transmision is autosomal dominant. For diagnosis of NF-1, two or more findings have to be present: six or more cafe au lait macules, two or more neurofibromas of any type, freckling in the axillary region, optic glioma, two or more lisch nodules (iris hamartomas), first degree relative with NF-1 or osseous lesion such as sphenoid dysplasia.

The most common CNS lesions in a patient with NF-1 are high T2 signal lesions in the basal ganglia, cerebellum, internal capsule and brain stem. These are believed to be areas of vacuolar or spongiotic change. These usually do not cause mass effect and do not enhance. The lesions tend to regress with increasing age.