Dysplastic white matter lesions in patient with Neurofibromatosis 1

Abstract

Dysplastic white matter lesions/unidentified bright objects /Foci of abnormal signal intensities (FASi’s) in brain MRI are the commonest intracranial abnormality with Neurofibromatosis 1 seen in approximately 70-75% of patients. They are usually multiple, small in size and are typically located in globus pallidus, brainstem, centrum semiovale, thalamus, internal capsule, corpus callosum, and cerebellum. Although clinically silent, patients can present with reduced attention span however neuropsychological functioning of these lesions depends upon the region involved. NF1 lesions should be kept as differential for any hyperintense lesion in basal ganglia and caution is advised not to confuse these lesions with malignant lesions like gliomas as biopsies from these lesions showed benign etiology. Parental counselling regarding the prognosis is very important to alleviate unnecessary apprehension. Interval follow-up is advised for large lesions causing mass effect, showing contrast enhancement or when lesions are located in optic pathway.

Keywords

• neurofibromatosis-1
• dysplastic white matter lesions
• unidentifi ed bright objects
• foci of abnormal signal intensities
• cognition