Long term motor function after neonatal stroke: Lesion localization above all

Abstract

Motor outcome is variable following neonatal arterial ischemic stroke (NAIS). We analyzed the relationship between lesion characteristics on brain MRI and motor function in children who had suffered from NAIS. Thirty eight full term born children with unilateral NAIS were investigated at the age of seven. 3D T1- and 3D FLAIR-weighted MR images were acquired on a 3T MRI scanner. Lesion characteristics were compared between patients with and without cerebral palsy (CP) using the following approaches: lesion localization either using a category-based analysis, lesion mapping as well as voxel-based lesion-symptom mapping (VLSM). Using diffusion-weighted imaging the microstructure of the cortico-spinal tract (CST) was related to the status of CP by measuring DTI parameters. Whereas children with lesions sparing the primary motor system did not develop CP, CP was always present when extensive lesions damaged at least two brain structures involving the motor system. The VLSM approach provided a statistical map that confirmed the cortical lesions in the primary motor system and revealed that CP was highly correlated with lesions in close proximity to the CST. In children with CP, diffusion parameters indicated microstructural changes in the CST at the level of internal capsule and the centrum semiovale. White matter damage of the CST in centrum semiovale was a highly reproducible marker of CP. This is the first description of the implication of this latter region in motor impairment after NAIS. In conclusion, CP in childhood was closely linked to the location of the infarct in the motor system.

Association of transcallosal motor fibres with function of both hands after unilateral neonatal arterial ischemic stroke

“…As part of the AVCnn study, 33 7‐year‐old children (13 females, 20 males; mean age 7y 3mo [SD 2.46mo], range 6y 11mo–7y 11mo) with a history of unilateral NAIS of the middle cerebral artery (MCA) territory participated in a follow‐up investigation with 3T magnetic resonance imaging (MRI) and motor evaluation. The participants in this study were the same as in our previous study, except for five participants where neither diffusion‐weighted imaging nor box and blocks test (BBT, see below) data were available. The recruitment criteria of the participants were given in mode details in the previous cohort description .…”

“…The participants in this study were the same as in our previous study, except for five participants where neither diffusion‐weighted imaging nor box and blocks test (BBT, see below) data were available. The recruitment criteria of the participants were given in mode details in the previous cohort description . Further sample characteristics are presented in Table .…”

“… Participant numbers correspond to Table I in Dinomais et al F, female; M, male; R, right; L, left; N, normal; hemi, hemiplegia; contraBBT, box and blocks test score for the contralesional hand; ipsiBBT, box and blocks test score for the ipsilesional hand; mCC, motor part of the corpus callosum; rCC, rest of the corpus callosum; wCC, whole corpus callosum. …”

“…As described before, a high‐resolution 3D T1‐weighted image was obtained covering the whole brain (176 sagittal slices, repetition time 2300ms, echo time 4.18ms, field of view 256mm, flip angle=9°, voxel size 1×1×1mm 3 ) as well as a diffusion‐weighted dual spin‐echo planar imaging sequence with 30 diffusion‐weighted directions and a diffusion‐weighting of b=1000s/mm 2 (repetition time 9500ms, echo time 86ms, 40 slices, voxel size 1.875×1.875×3mm 3 ). Diffusion‐weighted images were processed using the MRtrix software package (http://www.mrtrix.org), reconstructing the transcallosal motor pathways using probabilistic tractography based on constrained spherical deconvolution …”

Diagnosing cerebral palsy in full‐term infants

“…However, the asymmetry can also present later, after 6–9 months following cortical pruning and maladaptive response to injury – thus, early intervention is critical for the preservation and reorganisation of motor function. Single or multiple disabilities, such as hemiplegic CP, epilepsy, cognitive or behavioural disorders, may be present following perinatal stroke depending on the location of the lesion …”