Frequency analysis of CSFP in patients with AD vs. AD-NPH syndrome. AD subjects by NINDS-ADRDA (Alzheimer's Disease and Related Disorders Association) criteria (n = 222) were initially screened to exclude NPH. 181 of these 222 patients had CSF pressure measurements (supine position). Seven subjects (4%) had a CSFP 220 mmH2O or greater, i.e., higher than the mean CSFP of 103 mmH2O for the AD-only group. The 7 subjects with elevated pressure had NPH as well as AD, i.e., the NPH-AD syndrome. The larger CSFP peak corresponds to the AD-only group; the smaller peak (higher pressures) pertains to AD-NPH hybrids. Reproduced from Silverberg et al .