###### Abstract  
Syntactic deficits are not a core symptom of the semantic variant of primary progressive aphasia (svPPA). However, some studies indicate syntactic impairments that deteriorate with progress of the disease. The study addresses the presence of a syntactic deficit and its association with clinical, neuropsychological, neuroanatomical and demographic variables. Nine individuals with svPPA were tested with a cognitive screening test (Addenbrooke's Cognitive Examination, ACE-R), a language screening test (Boston Diagnostic Aphasia Examination--BDAE) and a syntactic test (object question elicitation). Additionally, the regional cerebral flow was measured with brain single-photon emission computed tomography (SPECT). The results indicated significant impairment in the production of object questions for some patients. Performance on these clauses was not predicted by the ACE-R or by hypoperfusion in the language areas. While there was no evidence for an effect of disease duration on syntactic performance, the results reveal a potential effect of the age of symptom onset. Furthermore, the results reveal a significant association between the performance in BDAE and the years of education and production of object questions. Overall, these results indicate a significant specific deficit in syntax for some patients with svPPA and highlight the importance of the premorbid educational status for the progress of the disease. primary progressive aphasia; semantic variant; syntax; SPECT; disease duration; neuropsychological screening; age; education +
Footnote †: journal: Medical  
At this point we should note that there are still some unresolved questions with respect to differential diagnosis. For example, concerning fluency, it has been repeatedly shown that it is dissociated from agrammatic deficits [4; 5] (see also [PERSON] and [PERSON] [3] and [PERSON] [6] for reviews). On the other hand, agrammatic language (for some authors and/or non-fluent speech [6]) present with word comprehension deficits can manifest in speakers with mixed PPA, i.e., a subtype that does not conform to any of the variants mentioned above. Similarly, there are different approaches concerning the domain specificity of the semantic deficits in svPPA. Specifically, [PERSON] et al. [1] state that while verbal deficits are the most prominent symptom in the early stages of PPA, nonverbal semantic deficits are not excluded in svPPA. However, according to more recent approaches, nonverbal semantic deficits are not considered a symptom of svPPA, but rather, they demarcate a different syndrome, namely semantic dementia [2; 3]. Independently of the inclusion of nonverbal semantic disorders as a symptom of svPPA, syntactic deficits are not considered a prominent symptom in this subtype. As a consequence, few studies have explored syntactic production, mainly by means of non-constrained spontaneous speech samples and less by means of constrained tasks, and these studies have yielded inconsistent results. Moreover, even in studies that suggest the presence of a syntactic deficit in svPPA, it remains largely unclear how it is related to the general cognitive and language abilities, and particularly, the unequivocal semantic deficit. Connected to this, it is up for debate how the manifestation of syntactic deficits in svPPA is modulated by the extent of brain atrophy in specific brain areas and/or the duration of the disease. Additionally, although PPA and its progress manifest large individual variation, the effects of demographic variables such as age and years of education have scarcely been addressed in the literature. Finally, the manifestation of syntactic deficits in svPPA has been explored in a small set of languages so far. Investigation of a larger set of languages with different typological features is, thus, necessary for establishing whether there is syntactic impairment and, if at all, for understanding thoroughly the extent and the nature thereof.