Sensory tractography and robot‐quantified proprioception in hemiparetic children with perinatal stroke

Abstract

Perinatal stroke causes most hemiparetic cerebral palsy, resulting in lifelong disability. We have demonstrated the ability of robots to quantify sensory dysfunction in hemiparetic children but the relationship between such deficits and sensory tract structural connectivity has not been explored. It was aimed to characterize the relationship between the dorsal column medial lemniscus (DCML) pathway connectivity and proprioceptive dysfunction in children with perinatal stroke. Twenty-nine participants (6-19 years old) with MRI-classified, unilateral perinatal ischemic stroke (14 arterial, 15 venous), and upper extremity deficits were recruited from a population-based cohort and compared with 21 healthy controls. Diffusion tensor imaging (DTI) defined DCML tracts and five diffusion properties were quantified: fractional anisotropy (FA), mean, radial, and axial diffusivities (MD, RD, AD), and fiber count. A robotic exoskeleton (KINARM) tested upper limb proprioception in an augmented reality environment. Correlations between robotic measures and sensory tract diffusion parameters were evaluated. Lesioned hemisphere sensory tracts demonstrated lower FA and higher MD, RD, and AD compared with the non-dominant hemisphere of controls. Dominant (contralesional) hemisphere tracts were not different from controls. Both arterial and venous stroke groups demonstrated impairments in proprioception that correlated with lesioned hemisphere DCML tract diffusion properties. Sensory tract connectivity is altered in the lesioned hemisphere of hemiparetic children with perinatal stroke. A correlation between lesioned DCML tract diffusion properties and robotic proprioceptive measures suggests clinical relevance and a possible target for therapeutic intervention. Hum Brain Mapp 38:2424-2440, 2017. © 2017 Wiley Periodicals, Inc.

Corticospinal tract diffusion properties and robotic visually guided reaching in children with hemiparetic cerebral palsy

“…Visually guided reaching performance is summarized in Table and reported in detail elsewhere (Kuczynski et al, , under review). Reaching data was not obtained in one AIS participant due to difficulty completing the task with the affected limb.…”

“…Several studies in children with hemiparesis have demonstrated that reduced FA, indicative of more random diffusion within the stroke‐affected CST, is associated with poor motor function in the contralateral, affected limbs (van der Aa et al, ; Lennartsson et al, ; Roze et al, ; Yoshida et al, ). More recently, we have investigated the relationship between sensory dysfunction (Kuczynski, Dukelow, Semrau, & Kirton, ; Kuczynski, Semrau, Kirton, & Dukelow, ) and diffusion properties of the dorsal column medial lemniscus sensory pathways in children with perinatal stroke and hemiparetic CP (Kuczynski et al, ). We found that diffusion properties were abnormal (reduced FA and fiber count; increased diffusivities) in stroke subjects, the degree of which was associated with clinical measures of impaired sensorimotor function.…”

“…In these studies, motor function as measured by robotic devices correlates with clinical measures of disability (Semrau et al, ). We have recently characterized detailed dysfunction of visually guided reaching in both upper extremities of children with perinatal stroke and cerebral palsy (Kuczynski et al, , under review). The relationship between CST structural connectivity and such robotic measures of motor performance in disabled children with perinatal stroke has not been investigated.…”

Fatigue in children with perinatal stroke: clinical and neurophysiological associations

“…In contrast to our predictions and previous data in adults with stroke, 9 the association between fatigue and motor performance was only present in the less affected hand. 29,30 Because children with unilateral CP favour their less affected hand, it follows that the sensory consequences of movement and performance in this hand may be the most likely to be those perceived and interpreted by the child. 24 Improving performance in the more affected hand is frequently the primary focus of rehabilitation.…”

Proprioception and motor performance after stroke: An examination of diffusion properties in sensory and motor pathways

“…The DCML carries proprioceptive and cutaneous information from the periphery, ascending the dorsal columns of the spinal cord through the medial lemniscus to the thalamus, and finally, the primary somatosensory cortex via the posterior limb of the internal capsule (PLIC). While one group has examined the DCML in patients with multiple sclerosis (Fling, Dutta, Schlueter, Cameron, & Horak, ) and members of our team have studied the DCML in children with cerebral palsy (Kuczynski et al, ), the importance of DCML microstructure after adult stroke remains unexplored. Furthermore, little is known about connections between the POCG and SMG or HG.…”