59-year-old male with previous stroke for evaluation of acute worsening left leg weakness. Multiple areas of ischemia of different ages are noted in the pons. A focus of diffusion restriction with increased T2/FLAIR signal is now noted in the right aspect of the pons, compatible with. There has been interval small chronic infarct in the ventral left aspect of the pons. There has been interval evolution of a now chronic focus infarct involving the mesial dorsal pons. Scattered foci of T2 hyperintensity in the periventricular and subcortical white matter compatible with chronic small vessel ischemic changes. There are also small chronic bilateral thalamic and basal ganglia lacunar infarcts. Note is made of a prominent perivascular space in the left insula. There is no evidence of intracranial hemorrhage, mass or edema. The ventricles and basal cisterns are normal in size and configuration. The expected intracranial vascular flow voids are present. The paranasal sinuses are clear. The visualized mastoid air cells are clear. The orbits are unremarkable. Note is again made of a 13 mm sebaceous cyst overlying the left zygoma.MRA head:There is approximately 70% narrowing of the mid to distal M1 segment of the right middle cerebral artery proximal to its bifurcation. The anterior and middle cerebral arteries do not otherwise demonstrated areas of significant stenoses. The posterior communicating arteries are diminutive bilaterally. The V4 segment of the right vertebral artery is mildly narrowed with loss of flow related enhancement. The left vertebral artery is dominant. The basilar artery and posterior cerebral arteries are normal in caliber. No significant intracranial aneurysm. MRA neck:The left common carotid artery originates off of the innominate artery. The carotid arteries are widely patent with normal contour and caliber throughout. The left vertebral artery is normal caliber and contour for the remainder of its course. The origin of the right vertebral artery remains stenotic. Mild stenosis of the distal vertebral artery is again noted as it pierces the dura. This is compatible with a dissection of indeterminate age. There is a subcutaneous lipoma incidentally noted in the right posterior paraspinal soft tissues.
1. Acute to subacute lacunar infarct in the right aspect of the pons. Remote lacunar infarcts involving the mesial dorsal and ventral left aspects of the pons. 2. Unchanged stenoses of the right vertebral artery origin and distally as it enters the dura with associated findings suggesting slow flow.3. Right middle cerebral artery stenosis, as on the prior examination. No evidence of new flow-limiting stenosis, occlusion, or aneurysm in the major intracerebral arteries.4. Periventricular and subcortical white matter lesions of a mild degree are nonspecific. At this age they are most likely vascular related. 5. chronic lacunar infarcts in the bilateral basal ganglia and thalami.