We plan to elucidate the complex gross anatomy of the medial longitudinal fasiculus and review the imaging anatomy of the medial longitudinal fasiculus. We will enroll subjects in the study in order to perform a retrospective case review series of MRI exams to evaluate abnormalities on MRI of the medial longitudinal fasiculus, type of pathology, and corresponding demographic data and clinical presentation. We would like to increase awareness of these subtle abnormalities for the general radiologist.

Inclusion criteria will include all patients with documented lesion involving the medial longitudinal fasiculus on brain MRI reports obtained through Nuance M power software. This will also provide patient identification information we will utilize to record patient demographic information and clinical presentation. Two neuroradiologists will evaluate the MRI exam and record the type of pathology in the medial longitudinal fasiculus and the location and then using the associated medical record and accession number we will access the electronic medical record to access the demographic information for the patient and clinical presentation.

Exclusion criteria will be patients that do no have the keyword "medial longitudinal fasiculus" in their MRI report.