Cognitive-communication features relevant to speech and language therapy in Lewy Body Dementia

Lewy Body Dementia (LBD) is characterized by fluctuating cognition, executive dysfunction, visuospatial impairment, and parkinsonian features that may jointly affect communication. Despite the clinical importance of these difficulties, direct evidence for speech and language therapy (SLT) in LBD remains limited. This structured narrative review critically synthesizes neuropsychological, linguistic, discourse, motor-speech, and clinically relevant intervention evidence for SLT assessment and management in LBD. Literature published from January 2010 to February 2026 was identified through structured searches of PubMed, Scopus, Web of Science, and PsycINFO, supplemented by reference-list screening. Evidence was organized by directness to LBD, study design, sample characteristics, communication outcomes, and major methodological limitations. The strongest direct evidence indicates that communication difficulties in LBD are heterogeneous and reflect interactions among executive-attentional dysfunction, cognitive fluctuations, visuospatial-perceptual disturbance, pragmatic/discourse impairment, and parkinsonian speech features. Comparative empirical studies suggest relatively greater executive/fluency and prosodic-acoustic involvement in DLB than in Alzheimer's disease, whereas naming and semantic-language impairment may be more pronounced in Alzheimer's disease. Evidence for LBD-specific SLT intervention remains insufficient; therefore, proposed clinical strategies should be regarded as theoretically informed adaptations rather than established LBD treatments. The review proposes a multidimensional cognitive-communication framework while emphasizing the need for repeated, ecologically valid assessment and LBD-specific intervention studies.