Differences in somatosensory processing due to dominant hemispheric motor impairment in cerebral palsy

Inmaculada Riquelme,Pedro Montoya,Ignasi Cifre,Iván Padrón,Ana M González-Roldán

doi:10.1186/1471-2202-15-10

Abstract

BackgroundAlthough cerebral palsy (CP) is usually defined as a group of permanent motor disorders due to non-progressive disturbances in the developing fetal or infant brain, recent research has shown that CP individuals are also characterized by altered somatosensory perception, increased pain and abnormal activation of cortical somatosensory areas. The present study was aimed to examine hemispheric differences on somatosensory brain processing in individuals with bilateral CP and lateralized motor impairments compared with healthy controls. Nine CP individuals with left-dominant motor impairments (LMI) (age range 5–28 yrs), nine CP individuals with right-dominant motor impairments (RMI) (age range 7–29 yrs), and 12 healthy controls (age range 5–30 yrs) participated in the study. Proprioception, touch and pain thresholds, as well as somatosensory evoked potentials (SEP) elicited by tactile stimulation of right and left lips and thumbs were compared.ResultsPain sensitivity was higher, and lip stimulation elicited greater beta power and more symmetrical SEP amplitudes in individuals with CP than in healthy controls. In addition, although there was no significant differences between individuals with RMI and LMI on pain or touch sensitivity, lip and thumb stimulation elicited smaller beta power and more symmetrical SEP amplitudes in individuals with LMI than with RMI.ConclusionsOur data revealed that brain processing of somatosensory stimulation was abnormal in CP individuals. Moreover, this processing was different depending if they presented right- or left-dominant motor impairments, suggesting that different mechanisms of sensorimotor reorganization should be involved in CP depending on dominant side of motor impairment.

Highlights

Cerebral palsy (CP) is usually defined as a group of permanent motor disorders due to non-progressive disturbances in the developing fetal or infant brain, recent research has shown that cerebral palsy (CP) individuals are characterized by altered somatosensory perception, increased pain and abnormal activation of cortical somatosensory areas
We examined the effects of lateralized motor impairment on somatosensory brain processing by using somatosensory evoked potentials (SEP) in persons with bilateral CP
Comparison between individuals with cerebral palsy (CP) and healthy controls Somatosensory assessment Figure 1 displays mean scores of touch and pain sensitivity at the lip and thumb for healthy controls and CP individuals grouped by dominant side of motor impairment

Summary

Introduction

Cerebral palsy (CP) is usually defined as a group of permanent motor disorders due to non-progressive disturbances in the developing fetal or infant brain, recent research has shown that CP individuals are characterized by altered somatosensory perception, increased pain and abnormal activation of cortical somatosensory areas. A case study by Ragazzoni and colleagues (2002) [27] has further showed that somatosensory function of the affected (right) arm was preserved, whereas motor function was poor despite fast-conducting ipsilateral cortico-motoneuronal output from primary motor cortex of the intact hemisphere to the affected arm This finding seems to suggest that different forms of motor and somatosensory reorganization are involved in congenital brain injury, and that fast-conducting connections between primary cortex areas and ipsilateral spinal cord are not sufficient for preservation or recovery of function

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