CNS manifestations of NF1 - optic pathway glioma, neurofibroma, dural ectasia
Presentation
Referred to neurology for evaluation of skin lesions suspected to be neurofibromatosis. Complaining of worsening vision.
Patient Data
MRI head
Bulky optic chiasm, extending into the intracranial optic nerves, in keeping with an optic pathway glioma. These extend to the superior orbital foramina.
Normal pituitary fossa and infundibulum. Normal brainstem.
White matter hyperintensity in right centrum semiovale (maybe a FASI or related to small vessel change). Otherwise normal intra-axial signal.
MRI whole spine
Widened cervical and thoracic spinal canal. Enlarged bilateral C5-C8 dorsal root ganglia, consistent with neurofibromata. Normal cervical and thoracic cord, and conus.
Marked widening of lumbar canal, with vertebral scalloping and dilatation of the cul-de-sac to the second sacral segment. The sacral posterior elements are present but deformed. Appearances of dural ectasia. The lumbar nerve root ganglia are again enlarged (neurofibromata), particularly left S1 measuring approximately 3 cm.
Bladder wall thickening.
Follow-up MRI orbits
Limited sequences. Thickened non-enhancing optic nerves and optic chiasm. The intra-orbital nerves appear normal in size, and posteriorly the glioma extends to, not beyond, the hypothalamus.
Case Discussion
This patient with typical skin findings of neurofibromatosis type 1 (café au lait spots, axillary freckling, multiple cutaneous neurofibromata), was referred with concern about reduced visual acuity.
MRI head and spine demonstrated optic pathway glioma, multiple nerve root neurofibromata and dural ectasia, all consistent with NF1. These findings have not changed on follow-up and remain under radiological and clinical review.
The bladder wall thickening detected on MR was confirmed to be ganglioneuroma on biopsy and managed conservatively.