40yoF with congenital nystagmus, episodical tinnitus, history of 3.5 month prematurity presenting with dizziness episodes and has upper motor neuron signs on The ventricles and sulci are within normal limits. The cisterns remain patent. There is no midline shift or mass effect. There are no areas of abnormal signal or pathological enhancement. The pituitary stalk measures up to 2 mm in thickens. There is no diffusion abnormality. There is no acute intracranial hemorrhage. No extra-axial fluid collection is identified.The meatal loop of the right anterior inferior cerebellar artery extends far into the right internal auditory canal. The bilateral vestibulocochlear nerves are intact.
1. Normal non contrast brain MR.2. The meatal loop of the right anterior inferior cerebellar artery extends far into the right internal auditory canal.3. The pituitary stalk is at the upper limit of normal for thickness.