How does the interaction of presumed timing, location and extent of the underlying brain lesion relate to upper limb function in children with unilateral cerebral palsy?

Abstract

Background: Upper limb (UL) function in children with unilateral cerebral palsy (CP) may vary largely depending on presumed timing, location and extent of brain lesions. These factors might exhibit a complex interaction and the combined prognostic value warrants further investigation. This study aimed to map lesion location and extent and assess whether these differ according to presumed lesion timing and to determine the impact of structural brain damage on UL function within different lesion timing groups. Materials and methods:Seventy-three children with unilateral CP (mean age 10 years 2 months) were classified according to lesion timing: malformations (N=2), periventricular white matter (PWM, N=42) and cortical and deep grey matter (CDGM, N=29) lesions.Neuroanatomical damage was scored using a semi-quantitative MRI scale. UL function was assessed at the level of body function and activity level.Results: CDGM lesions were more pronounced compared to PWM lesions (p=0.0003).Neuroanatomical scores were correlated with a higher degree to UL function in the CDGM group (r s =-0.39 to r s =-0.84) compared to the PWM group (r rb =-0.42 to r s =-0.61). Regression analysis found lesion location and extent to explain 75% and 65% (p<0.02) respectively, of the variance in AHA performance in the CDGM group, but only 24% and 12% (p<0.03) in the PWM group. Conclusions:In the CDGM group, lesion location and extent seems to impact more on UL function compared to the PWM group. In children with PWM lesions, other factors like cortical reorganization and structural connectivity may play an additional role.

Understanding the impact of bilateral brain injury in children with unilateral cerebral palsy

“…It was observed that AHA and MUUL scores between children with unilateral and bilateral brain injury were not statistically significantly different (Table ), despite lesions being more severe based on the semi‐quantitative scoring. This result is consistent with previous findings that the presence of unilateral or bilateral damage had no predictive value on hand performance (Holmefur et al, ; Mailleux et al, ). Furthermore, bilateral brain injury being thought to have a protective effect with respect to brain reorganization, by preventing reorganization towards the dominant hemisphere that is known to lead to poorer functional outcomes (Eyre et al, ).…”

Corticospinal Tract Wiring and Brain Lesion Characteristics in Unilateral Cerebral Palsy: Determinants of Upper Limb Motor and Sensory Function

“…The timing of the lesion during gestation is closely related to the type of the damaged tissue and can be classified into three categories: malformations (1 st and 2 nd trimesters of pregnancy), periventricular lesion (PV, early 3 rd trimester), and corticosubcortical lesions (CSC, late 3 rd trimester and around birth) [ 7 ]. Previous studies investigating the impact of lesion timing on UL function have shown that individuals with a later lesion (i.e., CSC lesions) present with poorer UL motor and sensory functions [ 2 , 3 , 5 ]. Besides lesion timing, lesion location and extent have shown to play an important role in determining UL function, whereby damage to the posterior limb of the internal capsule (PLIC) and the basal ganglia, and a larger lesion extent is related to worse UL motor and sensory functions [ 2 , 3 ].…”

“…Previous studies investigating the impact of lesion timing on UL function have shown that individuals with a later lesion (i.e., CSC lesions) present with poorer UL motor and sensory functions [ 2 , 3 , 5 ]. Besides lesion timing, lesion location and extent have shown to play an important role in determining UL function, whereby damage to the posterior limb of the internal capsule (PLIC) and the basal ganglia, and a larger lesion extent is related to worse UL motor and sensory functions [ 2 , 3 ]. However, there is still large variability in UL function that remains unexplained based on these factors.…”

“…Whilst the role of lesion timing, location, and extent has been well investigated [ 2 , 3 , 14 ], only a few studies examined the impact of the CST wiring on UL function and they often have several limitations (i.e., small sample sizes, ordinal scoring of impairments, and limited to motor deficits) [ 5 , 10 , 15 ]. Moreover, studies thus far focused on each factor independently, whereas only one study described the impact of the CST wiring and lesion timing on UL function in uCP [ 10 ], and only one study reports the impact of CST wiring and lesion extent in children with PV lesions [ 4 ].…”

Randomized controlled trial combining constraint-induced movement therapy and action-observation training in unilateral cerebral palsy: clinical effects and influencing factors of treatment response

“…Similarly, mirror movements have a negative impact on UL function [21][22][23], yet their value to influence treatment response remains unknown. Among potential neurological factors are the underlying lesion type (predominantly white matter vs. grey matter damage) and the corticospinal tract (CST) wiring pattern, due to their value in explaining variability in UL function [24][25][26]. Thus far, only one small study showed improvements after CIMT regardless of the lesion type [27].…”