Table 1.
Principal demographic and clinical characteristics of studied subjects.
Abbreviations: HET = heterozygous; HOM = homozygous; HC = healthy controls; SD = standard deviation; LEDD = Levodopa equivalent daily dose; UPDRS = Unified Parkinson's Disease Rating Scale; MOCA = Montreal Cognitive Assessment; H&Y = Hoehn and Yahr scale.
Table 2.
Performance scores obtained by HET and HOM individuals on neuropsychological tests.
In brackets cut-off for normative values; in bold characters pathological values. Abbreviations: Edu: educational level; HET: heterozygous; HOM: homozygous; MOCA: Montreal cognitive assessment; LTM: Long term memory; STM: Short term memory; Imm: Immediate recall; Del: delayed recall; RMP47: Raven’s Progressive Matrices; MCST: Modified Card Sorting Test- criteria.
Table 3.
Changes in FC in five networks of interest.
Brain areas of significant FC alteration in RS-networks (A) and of significant correlation between Corsi score and FC (B) HOM ARPD.
Fig 1.
Between group FC changes within the RS-fMRI networks of interest.
This figure illustrates between-group differences in functional brain connectivity observed in individual networks: A) the default mode network (DMN), B) the executive network (ExN), and C) the right fronto-parietal network (rFP). In all cases, the networks (main effect of groups) are shown in yellow. Red areas show the regional pattern of reduced connectivity in homozygous mutation carriers (HOM) as compared to healthy controls (HC). Blue areas show the regional pattern of reduced connectivity in heterozygous mutation carriers (HET) as compared to HC. Pink areas show the regional pattern of reduced connectivity in HOM as compared to HET. For each contrast, the signal plots on the right show the group level of connectivity at the peak of some clusters.
Fig 2.
Associations between single network FC and spatial working memory performance in HOM patients.
Within each network (shown in yellow), red areas illustrate the brain regions whose functional connectivity was positively associated with scores reported by homozygous (HOM) mutation carriers at the Corsi test (spatial working memory). These regions included: the left middle frontal gyrus within the left fronto-parietal network (A); the right superior frontal gyrus within the right fronto-parietal network (B); the left paracingulate gyrus within the salience network (C); and the right anterior cingulate gyrus within the executive network (D).
Table 4.
Inter-network correlation results.
Mean lag, Pearson r index and p values of the inter-network FC correlations in the group of healthy controls (HC), HET individuals and HOM patients.
Fig 3.
Panel A shows the mean (SD) internetwork z scores for each studied group (i.e., healthy controls, HC; homozygous (HOM) and heterozygous (HET) mutation carriers) in three pairs of networks: salience network and right fronto-temporal network (SN-rFP); default mode network and right fronto-temporal network (DMN—rFP); salience network and default mode network (SN-DMN). Asterisks highlight significant between-group differences. Panel B illustrates the significant correlations, obtained in HOM (green-square marks) and HET (red-rhomb marks) mutation carriers altogether, between mean internetwork z scores in SN-rFP and SN-DMN pairs of networks and individual scores obtained at Corsi test (spatial working memory span).