Background/Aim: To investigate in variants of primary progressive aphasia (PPA) the association between current clinical and neuroimaging criteria and biochemical/genetic markers at the individual level. Methods: Thirty-two PPA patients were classified as non-fluent/agrammatic (nfvPPA), semantic (svPPA), or logopenic variant (lvPPA) or as unclassifiable (uPPA). In all patients, we evaluated the neuroimaging criteria (magnetic resonance imaging and/or single photon emission computed tomography/positron emission tomography) of each variant and studied serum progranulin levels, APOE genotype and Alzheimer’s disease (AD)-cerebrospinal fluid (CSF) biomarkers. Cases with a first-degree family history of early-onset dementia were genetically tested. Results: Ten of 15 (66%) nfvPPA, 5/5 (100%) svPPA and 7/7 (100%) lvPPA patients showed at least one positive neuroimaging-supported diagnostic criterion. All lvPPA and 3/5 (60%) uPPA patients presented AD-CSF biomarkers, which were absent in nfvPPA and svPPA cases. Four (27%) nfvPPA patients had dementia-causing mutations: 2 carried a GRN mutation and 2 the C9ORF72 hexanucleotide expansion. Conclusions: There was an excellent association between clinical criteria and neuroimaging-supported biomarkers in svPPA and lvPPA, as well as with AD-CSF biochemical markers in the lvPPA. Neuroimaging, biochemical and genetic findings in nfvPPA were heterogeneous. Incorporating biochemical/genetic markers into the PPA clinical diagnosis would allow clinicians to improve their predictions of PPA neuropathology, especially in nfvPPA and uPPA cases.

Reduced striatal tracer uptake in nfvPPA patients prior to clinical parkinsonism can be detected by 123I-FP-CIT-SPECT, especially in those with nfvPPA/bio-, suggesting subclinical nigrostriatal degeneration. Decreased striatal 123I-FP-CIT binding might identify PPA patients at increased risk of developing atypical parkinsonian syndromes, probably related to tau-pathology.

Background: The semantic variant of primary progressive aphasia (svPPA) is characterized by a progressive loss of semantic knowledge impairing the ability to name and to recognize the meaning of words. Objective: We aimed to evaluate the immediate and short-term effect of errorless learning speech therapy on the naming and recognition of commonly used words in patients with svPPA. Methods: Eight participants diagnosed with svPPA received 16 sessions of intensive errorless learning speech therapy. Naming and word comprehension tasks were evaluated at baseline, immediately postintervention, and at follow-up after 1, 3, and 6 months. These evaluations were performed using two item sets (a trained list and an untrained list). Results: In the naming tasks, patients showed a significant improvement in trained items immediately after the intervention, but that improvement decayed progressively when therapy ended. No improvements were found either in trained comprehension or in untrained tasks. Conclusion: Errorless learning therapy could improve naming ability in patients with svPPA. This effect may be due to the relative preservation of episodic memory, but the benefit is not maintained over time, presumably because there is no consolidation.

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