Cerebellar atrophy in non‐fluent variant primary progressive aphasia correlates with disease severity and cognitive decline

Abstract

AbstractBackgroundThe role of the cerebellum in cognitive function has been extensively investigated in the last decades. The aim of our work was to characterize cerebellar atrophy in non‐fluent variant primary progressive atrophy (nfvPPA) and to determine whether its atrophy is associated with cognitive impairment.MethodSixteen patients with nfvPPA (mean age 59.6±9.2 years, 7 males) and 10 healthy controls (65.6±11.3 years, 4 males) were included in the study. Disease duration ranged from 12 to 84 months. Notably, the patients had no clinical signs of cerebellar involvement. All participants underwent brain MRI and cognitive assessment. A whole brain VBM analysis between patients and controls was carried out using SPM12. The relationship between clinical data and grey matter atrophy of cerebellum and its distinct areas (anterior lobe, posterior lobe, vermis, left and right hemispheres) was assessed by correlation analysis using the Spearman's rank correlation coefficient.ResultVBM revealed a significant decline in grey matter (GM) volume in the anterior (specifically, 4, 5 and 6 lobules) and posterior (specifically, Crus I and II, 7b and 8 lobules) cerebellar lobes bilaterally compared to controls (Figure 1). Correlation analysis revealed a significant correlation between the posterior lobe GM volume and disease severity and total Addenbrooke Cognitive Examination score (r = ‒0.62, p = 0.01 and r = 0.69, p = 0.028, respectively). No correlations with other clinical manifestations and neuropsychological findings (disease duration, total MoCA and FAB scores, semantic and literal verbal fluency, Trail Making Test part B) were detected.ConclusionThe findings demonstrate that, even in the absence of clinical signs of cerebellar involvement, prominent cerebellar atrophy is characteristic of nfvPPA. This atrophy is associated with disease severity and contributes to cognitive dysfunction.The study was supported by RFBR 19‐015‐00533.