Correlation of quantitative sensorimotor tractography with clinical grade of cerebral palsy

Department of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
Neuroradiology (Impact Factor: 2.49). 08/2010; 52(8):759-65. DOI: 10.1007/s00234-010-0703-8
Source: PubMed


The purpose of this study was to determine whether tract-specific diffusion tensor imaging measures in somatosensory and motor pathways correlate with clinical grades as defined using the Gross Motor Function Classification System (GMFCS) in cerebral palsy (CP) children.
Quantitative diffusion tensor tractography was performed on 39 patients with spastic quadriparesis (mean age = 8 years) and 14 age/sex-matched controls. All patients were graded on the basis of GMFCS scale into grade II (n = 12), grade IV (n = 22), and grade V (n = 5) CP and quantitative analysis reconstruction of somatosensory and motor tracts performed.
Significant inverse correlation between clinical grade and fractional anisotropy (FA) was observed in both right and left motor and sensory tracts. A significant direct correlation of mean diffusivity values from both motor and sensory tracts was also observed with clinical grades. Successive decrease in FA values was observed in all tracts except for left motor tracts moving from age/sex-matched controls to grade V through grades II and IV.
We conclude that white matter tracts from both the somatosensory and the motor cortex play an important role in the pathophysiology of motor disability in patients with CP.

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    • "Two DTI studies observed more severe damage in the posterior white matter fibers connecting the thalamus to the sensory cortex than in the descending corticospinal tracts in children with periventricular leukomalacia (PVL) (Hoon et al., 2002) and SCP (Nagae et al., 2007), despite a history and clinical presentation consistent with motor tracts. Compared to TD children, children with CP have been reported to have decreased fractional anisotropy (FA) and increased apparent diffusion coefficient (ADC) values for the motor and sensory tracks (Trivedi et al., 2010); for the affected side of the corticospinal tract (Son et al., 2007; Yoshida et al., 2010); and for the tracks on the side ipsilateral to the periventricular lesion in corticospinal tract, corticobulbar tract, and superior thalamic radiation (Thomas et al., 2005). Fundamental understanding of sensory function in CP children is extremely important, since SS input is an essential component of motor function, control, and development. "
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    ABSTRACT: Although cerebral palsy (CP) is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities [magnetoencephalography (MEG), diffusion tensor imaging (DTI), and resting-state fMRI] whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP), three with hemiplegic CP (HCP), and three typically developing (TD) children. Somatosensory (SS)-evoked fields (SEFs) were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the pre-central and post-central gyri in both hemispheres. The sensorimotor resting-state networks (RSNs) were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary SS cortex (S1). In five CP children, abnormal somatotopic organization was observed in the affected (or more affected) hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Resting-state functional MRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal SS processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.
    Full-text · Article · Sep 2014 · Frontiers in Human Neuroscience
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    • "Both diffusion MRI and tractography have previously been used to investigate CP in paediatric populations (see Scheck et al., 2012 for a systematic review). Perhaps not surprisingly, the corticospinal tract – the major descending motor pathway in the brain – has been the most frequent target of tractography investigations in CP (Chang et al., 2012; Chaturvedi et al., 2012; Glenn et al., 2007; Holmström et al., 2011; Hoon et al., 2002; Koerte et al., 2011; Rha et al., 2012; Rose et al., 2011; Son et al., 2007, 2009; Thomas et al., 2005; Trivedi et al., 2010; Yoshida et al., 2010), with a recently increased interest in ascending sensory pathways (Chaturvedi et al., 2012; Hoon et al., 2002; Rha et al., 2012; Rose et al., 2011; Thomas et al., 2005; Trivedi et al., 2010; Yoshida et al., 2010). Other projection, association and commissural pathways have been investigated less frequently (Koerte et al., 2011; Thomas et al., 2005). "
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    ABSTRACT: Background Cerebral palsy (CP) is a term to describe the spectrum of disorders of impaired motor and sensory function caused by a brain lesion occurring early during development. Diffusion MRI and tractography have been shown to be useful in the study of white matter (WM) microstructure in tracts likely to be impacted by the static brain lesion. Aim The purpose of this study was to identify WM pathways with altered connectivity in children with unilateral CP caused by periventricular white matter lesions using a whole-brain connectivity approach. Methods Data of 50 children with unilateral CP caused by periventricular white matter lesions (5–17 years; manual ability classification system [MACS] I = 25/II = 25) and 17 children with typical development (CTD; 7–16 years) were analysed. Structural and High Angular Resolution Diffusion weighted Images (HARDI; 64 directions, b = 3000 s/mm2) were acquired at 3 T. Connectomes were calculated using whole-brain probabilistic tractography in combination with structural parcellation of the cortex and subcortical structures. Connections with altered fractional anisotropy (FA) in children with unilateral CP compared to CTD were identified using network-based statistics (NBS). The relationship between FA and performance of the impaired hand in bimanual tasks (Assisting Hand Assessment—AHA) was assessed in connections that showed significant differences in FA compared to CTD. Results FA was reduced in children with unilateral CP compared to CTD. Seven pathways, including corticospinal, thalamocortical, and fronto-parietal association pathways were identified simultaneously in children with left and right unilateral CP. There was a positive relationship between performance of the impaired hand in bimanual tasks and FA within the cortico-spinal and thalamo-cortical pathways (r2 = 0.16-0.44; p < 0.05). Conclusion This study shows that network-based analysis of structural connectivity can identify alterations in FA in unilateral CP, and that these alterations in FA are related to clinical function. Application of this connectome-based analysis to investigate alterations in connectivity following treatment may elucidate the neurological correlates of improved functioning due to intervention.
    Full-text · Article · Jun 2014 · Clinical neuroimaging
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    • "damage present in the thalamocortical tracts is related to reduced muscular strength and a more severe Gross Motor Function Classification System level in children with CP (Hoon et al. 2009; Trivedi et al. 2010). Because CP can involve damage to both the sensory and motor tracts, it is unclear whether these sensory deficits generally contribute to the motor impairments seen in these children, or if they are more independent symptoms that share a common cause (i.e., perinatal brain damage). "
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    ABSTRACT: Cerebral palsy (CP) results from a perinatal brain injury that often results in sensory impairments and greater errors in motor performance. Although these impairments have been well catalogued, the relationship between sensory processing networks and errors in motor performance has not been well explored. Children with CP and typically developing age-matched controls participated in this investigation. We used high-density magnetoencephalography (MEG) to measure event-related oscillatory changes in the somatosensory cortices following tactile stimulation to the bottom of the foot. In addition, we quantified the amount of variability or errors in the isometric ankle joint torques as these children attempted to match a target. Our results showed that neural populations in the somatosensory cortices of children with CP were desynchronized by the tactile stimulus, while those of typically developing children were clearly synchronized. Such desynchronization suggests that children with CP were unable to fully integrate the external stimulus into ongoing sensorimotor computations. Our results also indicated that children with CP had a greater amount of errors in their motor output when they attempted to match the target force, and this amount of error was negatively correlated with the degree of synchronization present in the somatosensory cortices. These results are the first to show that the motor performance errors of children with CP are linked with neural synchronization within the somatosensory cortices.
    Full-text · Article · Nov 2013 · Journal of Neurophysiology
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