CNS manifestations of neurofibromatosis type 1 (NF-1)
Patients with NF-1 may have plexiform neurofibromas, which are present along nerve distributions and insinuate within the fascial planes of the head and neck. Sphenoid wing dysplasia, with its resultant harlequin eye appearance, is also present at times. Areas of high T2-weighted signal intensity representing spongiform dysplasia are frequently present in the basal ganglia, brainstem, and cerebellum. Gliomas may develop anywhere along the optic pathway or in areas of spongiform dysplasia. In the spine, patients with NF-1 may develop lateral meningoceles, which herniate from the thecal sac into the thorax. Radiographs of the spine may also demonstrate posterior vertebral body scalloping (from dural ectasia), enlargement of the neural foramina (from neurofibromas), and inferior rib notching/remodeling secondary to the growth of the neurofibromas along the course of the intercostal nerves.