Firdaus Fabrice Hannanu1,2,3, Bernadette Naegele4, Marc Hommel1, Alexandre Krainik2,5, Olivier Detante3, Assia Jaillard6,7,8. 1. AGEIS, EA 7407 Université Grenoble Alpes, Grenoble, France. 2. Unité IRM 3T Recherche - IRMaGe, Inserm US 17 CNRS - UMS 3552 UGA, CHUGA, Grenoble, France. 3. Medical Faculty of Hasanuddin University, Makassar, Indonesia. 4. Centre Hospitalier Universitaire Grenoble Alpes (CHUGA), Stroke Unit Neurology, Grenoble, France. 5. Neuroradiologie, Pôle Imagerie, CHUGA, Grenoble, France. 6. AGEIS, EA 7407 Université Grenoble Alpes, Grenoble, France. Assia.Jaillard@univ-grenoble-alpes.fr. 7. Unité IRM 3T Recherche - IRMaGe, Inserm US 17 CNRS - UMS 3552 UGA, CHUGA, Grenoble, France. Assia.Jaillard@univ-grenoble-alpes.fr. 8. Pôle Recherche, CHUGA, Grenoble, France. Assia.Jaillard@univ-grenoble-alpes.fr.
Abstract
PURPOSE: The ipsilateral hand (ILH) is impaired after unilateral stroke, but the underlying mechanisms remain unresolved. Based on the degeneracy theory of network connectivity that many connectivity patterns are functionally equivalent, we hypothesized that ILH impairment would result from the summation of microstructural white matter (WM) disruption in the motor network, with a task-related profile. We aimed to determine the WM disruption patterns associated with ILH impairment. METHODS: This was a cross-sectional analysis of patients in the ISIS-HERMES Study with ILH and diffusion-MRI data collected 1 month post-stroke. Patients performed three tasks, the Purdue Pegboard Test (PPT), handgrip strength, and movement time. Fractional anisotropy (FA) derived from diffusion MRI was measured in 33 WM regions. We used linear regression models controlling for age, sex, and education to determine WM regions associated with ILH impairment. RESULTS: PPT was impaired in 42%, grip in 59%, and movement time in 24% of 29 included patients (mean age, 51.9 ± 10.5 years; 21 men). PPT was predicted by ipsilesional corticospinal tract (i-CST) (B = 17.95; p = 0.002) and superior longitudinal Fasciculus (i-SLF) (B = 20.52; p = 0.008); handgrip by i-CST (B = 109.58; p = 0.016) and contralesional anterior corona radiata (B = 42.69; p = 0.039); and movement time by the corpus callosum (B = - 1810.03; p = 0.003) i-SLF (B = - 917.45; p = 0.015), contralesional pons-CST (B = 1744.31; p = 0.016), and i-corticoreticulospinal pathway (B = - 380.54; p = 0.037). CONCLUSION: ILH impairment was associated with WM disruption to a combination of ipsilateral and contralesional tracts with a pattern influenced by task-related processes, supporting the degeneracy theory. We propose to integrate ILH assessment in rehabilitation programs and treatment interventions such as neuromodulation.
PURPOSE: The ipsilateral hand (ILH) is impaired after unilateral stroke, but the underlying mechanisms remain unresolved. Based on the degeneracy theory of network connectivity that many connectivity patterns are functionally equivalent, we hypothesized that ILH impairment would result from the summation of microstructural white matter (WM) disruption in the motor network, with a task-related profile. We aimed to determine the WM disruption patterns associated with ILH impairment. METHODS: This was a cross-sectional analysis of patients in the ISIS-HERMES Study with ILH and diffusion-MRI data collected 1 month post-stroke. Patients performed three tasks, the Purdue Pegboard Test (PPT), handgrip strength, and movement time. Fractional anisotropy (FA) derived from diffusion MRI was measured in 33 WM regions. We used linear regression models controlling for age, sex, and education to determine WM regions associated with ILH impairment. RESULTS: PPT was impaired in 42%, grip in 59%, and movement time in 24% of 29 included patients (mean age, 51.9 ± 10.5 years; 21 men). PPT was predicted by ipsilesional corticospinal tract (i-CST) (B = 17.95; p = 0.002) and superior longitudinal Fasciculus (i-SLF) (B = 20.52; p = 0.008); handgrip by i-CST (B = 109.58; p = 0.016) and contralesional anterior corona radiata (B = 42.69; p = 0.039); and movement time by the corpus callosum (B = - 1810.03; p = 0.003) i-SLF (B = - 917.45; p = 0.015), contralesional pons-CST (B = 1744.31; p = 0.016), and i-corticoreticulospinal pathway (B = - 380.54; p = 0.037). CONCLUSION: ILH impairment was associated with WM disruption to a combination of ipsilateral and contralesional tracts with a pattern influenced by task-related processes, supporting the degeneracy theory. We propose to integrate ILH assessment in rehabilitation programs and treatment interventions such as neuromodulation.
Authors: Jennifer A Semrau; Troy M Herter; Jeffrey M Kenzie; Sonja E Findlater; Stephen H Scott; Sean P Dukelow Journal: Neurorehabil Neural Repair Date: 2017-04-26 Impact factor: 3.919
Authors: U Ziemann; K Ishii; A Borgheresi; Z Yaseen; F Battaglia; M Hallett; M Cincotta; E M Wassermann Journal: J Physiol Date: 1999-08-01 Impact factor: 5.182