Figure 3. Rate of change of ventricular brain volume. MRI scans were performed at 2.5–7 month intervals, as shown by open circles for each subject. (– – –), calculated mean rate of change for each group: National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) probable (Prob), possible (Poss) and negative (Neg) for Alzheimer's disease; (•), two NINCDS Neg subjects referred with objective memory complaints.