TY  - JOUR
AU  - Kuzu, Taylan D
AU  - Brinkmann, Elena
AU  - Bonkhoff, Anna K
AU  - Wunderle, Veronika
AU  - Bischof, Gérard N
AU  - Giehl, Kathrin
AU  - Schmieschek, Maximilian H T
AU  - Onur, Oezguer A
AU  - Jessen, Frank
AU  - Fink, Gereon R
AU  - Drzezga, Alexander
AU  - Weiss, Peter H
TI  - Apraxic deficits in Alzheimer's disease are associated with altered dynamic connectivity in praxis-related networks.
JO  - Neurobiology of aging
VL  - 157
SN  - 0197-4580
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - DZNE-2025-01296
SP  - 36 - 47
PY  - 2026
AB  - Apraxia is a common symptom in Alzheimer's disease (AD) that reduces autonomy and quality of life. However, the neural basis underlying apraxia in AD, for example, reflected by functional connectivity (FC) alterations, remains unexplored. We investigated static and dynamic FC using resting-state functional imaging in 14 patients with biomarker-confirmed AD pathology and 14 matched healthy participants. FC was estimated as average (static) and short-term (dynamic) connectivity strengths between motor- and praxis-related functional networks. Recurring connectivity patterns were clustered into dynamic states to compute temporal connectivity measures. Connectivity measures were used for correlations with apraxic deficits. In AD patients, static connectivity between visual and inferior parietal networks correlated with apraxic imitation (r = 0.762, PFDR = 0.043) and arm/hand gesture deficits (r = 0.848, PFDR = 0.020), while dynamic connectivity between these networks correlated with apraxic imitation deficits (r = 0.851, PFDR = 0.020). Dynamic FC analysis revealed a segregated and integrated state. AD patients spent more time overall (fraction time, PFDR < 0.001) and remained longer without switching (dwell time, PFDR = 0.004) in the segregated state. Both fraction (ρ = -0.858, PFDR = 0.015) and dwell time (ρ = -0.914, PFDR = 0.003) correlated with apraxic imitation deficits. Connectivity strengths between visual and inferior parietal networks and fraction time in the segregated state predicted apraxic imitation deficits (adjusted R2 = 0.782, P < 0.001). We conclude that apraxia in AD patients is associated with altered FC in praxis-related networks, suggesting FC as a potential clinical indicator for predicting motor-cognitive deficits.
KW  - Humans
KW  - Alzheimer Disease: complications
KW  - Alzheimer Disease: physiopathology
KW  - Alzheimer Disease: psychology
KW  - Alzheimer Disease: diagnostic imaging
KW  - Male
KW  - Female
KW  - Aged
KW  - Apraxias: etiology
KW  - Apraxias: physiopathology
KW  - Apraxias: diagnostic imaging
KW  - Nerve Net: physiopathology
KW  - Aged, 80 and over
KW  - Magnetic Resonance Imaging
KW  - Middle Aged
KW  - Brain: physiopathology
KW  - Aging (Other)
KW  - Alzheimer’s disease (Other)
KW  - Cologne apraxia screening (KAS) (Other)
KW  - Functional magnetic resonance imaging (Other)
KW  - Motor system (Other)
KW  - Praxis (Other)
KW  - Resting-state (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:41061587
DO  - DOI:10.1016/j.neurobiolaging.2025.09.007
UR  - https://pub.dzne.de/record/282473
ER  -