Sarcopenia, Low Muscle Strength, Cognitive Functions and Quality of Life in Parkinsonian Syndromes.

Objectives . Parkinsonian syndromes are disabling neurodegenerative diseases resulting in reduced muscle function/performance and sarcopenia but clinical manifestations could be systemic, including a deterioration of cognitive functions. As studies have reported an association between muscle dysfunction and cognitive decline and no information for these syndromes is available, we investigated the relationship between sarcopenia, and its components, with cognitive functions, fatigue and quality of life (QoL). Methods . Consecutive patients affected by parkinsonian syndromes were assessed for the presence of sarcopenia using the European Working Group on Sarcopenia in Older People-2 algorithm: low strength (handgrip strength: <27 kg [men]; <16 kg [women]); low appendicular skeletal muscle index (ASMI) by impedance (<7.0 kg/m2 [men]; <6.0 kg/m2 [women]). Cognitive functions were evaluated using the Montreal Cognitive Assessment (MoCA), the Mini-Mental State Examination (MMSE) and the Frontal Assessment Battery (FAB). Fatigue and QoL were assessed using the 16-item Parkinson's Disease Fatigue Scale (PFS-16) and the 39-item Parkinson's Disease Questionnaire (PDQ-39), respectively. Results . In total, 314 patients were included: 198 presented low strength (63.0% probable sarcopenia) and 68 (21.7%) out of these were diagnosed sarcopenia. After adjusting for multiple confounders, we observed a significant effect (worse score) of both low strength only and sarcopenia on MoCA, MMSE and QoL. Only reduced muscle strength had a relevant impact on the outcomes considered. Conclusions . In patients with parkinsonian syndromes, sarcopenia was associated with worse cognitive functions and QoL, with muscle dysfunction playing a major role. The prognostic impact of sarcopenia and its components needs to be addressed in prospective studies.