1. Altered brain morphometry in carpal tunnel syndrome is associated with median nerve pathology
- Author
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Cristina Malatesta, James D. Sheehan, Vitaly Napadow, Pia Mezzacappa, Leslie R. Morse, Yumi Maeda, Joseph Audette, Norman W. Kettner, Jessica Gerber, Claire McManus, Jieun Kim, and Stephen Cina
- Subjects
Pathology ,medicine.medical_specialty ,Diffusion tensor imaging (DTI) ,Cognitive Neuroscience ,CTS, carpal tunnel syndrome ,Nerve conduction velocity ,Article ,Voxel-based morphometry (VBM) ,White matter ,NCV, nerve conduction velocity ,03 medical and health sciences ,VBM, voxel-based morphometry ,0302 clinical medicine ,Peripheral nerve ,Neuroplasticity ,Fractional anisotropy (FA) ,medicine ,Radiology, Nuclear Medicine and imaging ,WM, white matter ,FA, fractional anisotropy ,Carpal tunnel syndrome ,030304 developmental biology ,0303 health sciences ,M1, primary motor cortex ,Radial diffusivity (RD) ,Brain morphometry ,medicine.disease ,Median nerve ,RD, radial diffusivity ,nervous system diseases ,medicine.anatomical_structure ,Neurology ,S1, primary somatosensory cortex ,GM, gray matter ,Neurology (clinical) ,DTI, diffusion tensor imaging ,Nerve conduction velocity (NCV) ,Axial diffusivity (AD) ,Brain Gray Matter ,Psychology ,030217 neurology & neurosurgery ,AD, axial diffusivity - Abstract
Objective Carpal tunnel syndrome (CTS) is a common median nerve entrapment neuropathy characterized by pain, paresthesias, diminished peripheral nerve conduction velocity (NCV) and maladaptive functional brain neuroplasticity. We evaluated structural reorganization in brain gray matter (GM) and white matter (WM) and whether such plasticity is linked to altered median nerve function in CTS. Methods We performed NCV testing, T1-weighted structural MRI, and diffusion tensor imaging (DTI) in 28 CTS and 28 age-matched healthy controls (HC). Voxel-based morphometry (VBM) contrasted regional GM volume for CTS versus HC. Significant clusters were correlated with clinical metrics and served as seeds to define associated WM tracts using DTI data and probabilistic tractography. Within these WM tracts, fractional anisotropy (FA), axial (AD) and radial (RD) diffusivity were evaluated for group differences and correlations with clinical metrics. Results For CTS subjects, GM volume was significantly reduced in contralesional S1 (hand-area), pulvinar and frontal pole. GM volume in contralesional S1 correlated with median NCV. NCV was also correlated with RD and was negatively correlated with FA within U-fiber cortico-cortical association tracts identified from the contralesional S1 VBM seed. Conclusions Our study identified clear morphometric changes in the CTS brain. This central morphometric change is likely secondary to peripheral nerve pathology and altered somatosensory afference. Enhanced axonal coherence and myelination within cortico-cortical tracts connecting primary somatosensory and motor areas may accompany peripheral nerve deafferentation. As structural plasticity was correlated with NCV and not symptomatology, the former may be a better determinant of appropriate clinical intervention for CTS, including surgery., Highlights ► CTS demonstrated reduced GM volume in S1, pulvinar, and frontal pole. ► GM volume in S1 was significantly correlated with median nerve conduction velocity. ► Median nerve velocity was linked to WM microstructure in tracts connected to S1.
- Published
- 2013
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