Left arm numbness. No evidence of acute ischemic or hemorrhagic lesion on the scan.Bilateral asymmetric high signal intensities on basal ganglia specifically globus pallidi on FLAIR images are seen. There is another lesion on the right side of cerebral peduncle which extends caudally to the level of upper pons. Interestingly, there is no imaging evidence of mass effects from these lesions except the left globus pallidus lesion.Those lesions do not show any restricted diffusion or susceptibility artifacts on gradient echo images.These findings are non specific thus the list of potential diagnosis could be very long.The differential diagnosis of these lesions include; demyelinating disease, inflammatory disease such as Neuro-Behcet disease, chronic toxic lesion such as carbon monoxide or methanol, metabolic lesions such as chronic liver disease or diabetes related non ketonic hyperglycemia or post infectious lesion such as post acute demyelinating encephalomyelopathy. Gadolinium enhanced MRI with clinical correlation might be helpful to narrow down the differential diagnosis.The ventricles, sulci and cisterns are symmetric and unremarkable. Normal flow voids are identified in the major intracranial vessels. The paranasal sinuses and mastoid air cells are clear.3D time of flight MOTSA MRA brain images with maximum intensity projections of the anterior/posterior intracranial circulation demonstrate normal ICAs, MCAs and ACAs. Vertebrobasilar system appears to be normal.
1. Non specific bilateral globus pallidi as well as right cerebral peduncle, mid brain and upper pontine high signal intensity lesions on FLAIR images as described above. Gad enhanced MR images with clinical correlation are recommended. 2. Normal brain MRA.