Figure 6.

Road map for subtyping PPA. The road map can be used quantitatively, in which case ‘definite’ impairment can be defined through a z-score or deviation from normative values by a certain number of standard deviations. It can also be used qualitatively, in which case, ‘definite’ and ‘insignificant’ can be assessed on the basis of their prominence in the clinical assessment or impact on daily activities. The choice of tests can vary based on language, education and severity level. The branch point that depends on the integrity of repetition is particularly challenging in mild disease stages since so few of the patients, other than those in the PPA-G group, showed major impairments in this domain. NAT and SPPT(nc) = mean of the scores (for non-canonical sentences) on the NAT and on the Sentence Production Priming Test of the Northwestern Assessment of Verbs and Sentences; REP6 = a subset of the six most difficult items in the repetition subtest of the WAB; ? = unclassifiable.