Parkinson's disease: preoperative planning for DBS. The images are degraded by patient motion. Nevertheless, there is no evidence of acute intracranial hemorrhage or tumor. However, there is a left middle cranial fossa arachnoid cyst that measures up to 25 mm with mass effect upon the anterior temporal lobe. There is also scattered cerebral white matter T2 hyperintensity. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable. There are bilateral lens implants.
Left middle cranial fossa arachnoid cyst and probable small vessel ischemic disease of the white matter. Otherwise, unremarkable treatment-planning MRI.