[Speech disorders in neurodegenerative diseases as dysphasia manifestation]

To develop the classification and methodology for assessment of speech disorders in neurodegenerative diseases, and to identify the characteristics of speech disorders for various forms.

The study included 1016 patients with neurodegenerative diseases. Screening assessment identified 42.1% patients with speech disorders exceeding isolated dysarthria. Patients were assessed using the speech disorder test battery developed by the authors. Cluster, multifactor and contingency analyses were performed.

Nine subtypes of speech disorders were identified in neurodegenerative diseases that we denominated as dysphasia. Based on contingency analysis, the principal and the additional dysphasia variants were identified for each form of neurodegenerative pathology, which may contribute to better understanding of various phenotypes. Based on the general scheme of speech origination, the level of disorders typical for a given dysphasia subtype was identified.

The proposed classification enables identification of the subtypes of speech disorders for individual forms of neurodegenerative diseases. Introducing dysphasia concept to clinical practice will improve differential diagnosis and understanding of phenotypical heterogeneity of each nosological form as well as will facilitate therapy optimization.