MAPT and early-onset autosomal dominant Alzheimer disease: Increased ventricular size is commonly seen in neurodegenerative disorders such as Alzheimer disease, where the rate of ventricular volume change is significantly correlated with an increase in neurofibrillary tangles.22 The presence of neurofibrillary tangles and tau, hallmarks of Alzheimer disease, have been reported in the pathology of NS23,24 but also in 2 of 4 cases with OAE.23 Alternately, it is possible that the increased global atrophy in patients with NS could reflect tau-associated pathologic changes.