Resting-state functional magnetic resonance imaging and probabilistic diffusion tensor imaging demonstrate that the greatest functional and structural connectivity in the hand motor homunculus occurs in the area of the thumb Journal Article


Authors: Hamidian, S.; Vachha, B.; Jenabi, M.; Karimi, S.; Young, R. J.; Holodny, A. I.; Peck, K. K.
Article Title: Resting-state functional magnetic resonance imaging and probabilistic diffusion tensor imaging demonstrate that the greatest functional and structural connectivity in the hand motor homunculus occurs in the area of the thumb
Abstract: The primary hand motor region is classically believed to be in the "hand knob" area in the precentral gyrus (PCG). However, hand motor task-based activation is often localized outside this area. The purpose of this study is to investigate the structural and functional connectivity driven by different seed locations corresponding to the little, index, and thumb in the PCG using probabilistic diffusion tractography (PDT) and resting-state functional magnetic resonance imaging (rfMRI). Twelve healthy subjects had three regions of interest (ROIs) placed in the left PCG: lateral to the hand knob (thumb area), within the hand knob (index finger area), and medial to the hand knob (little finger area). Connectivity maps were generated using PDT and rfMRI. Individual and group level analyses were performed. Results show that the greatest hand motor connectivity between both hemispheres was obtained using the ROI positioned just lateral to the hand knob in the PCG (the thumb area). The number of connected voxels in the PCG between the two hemispheres was greatest in the lateral-most ROI (the thumb area): 279 compared with 13 for the medial-most ROI and 9 for the central hand knob ROI. Similarly, the highest white matter connectivity between the two hemispheres resulted from the ROI placed in the lateral portion of PCG (p < 0.003). The maximal functional and structural connectivity of the hand motor area between hemispheres occurs in the thumb area, located laterally at the "hand knob." Thus, this location appears maximal for rfMRI and PDT seeding of the motor area. © 2018 Mary Ann Liebert, Inc.
Keywords: adult; clinical article; controlled study; structure activity relation; plant seed; functional magnetic resonance imaging; white matter; human experiment; diffusion tensor imaging; functional connectivity; thumb; primary motor cortex; human; male; female; article; dti; pdt; hand motor; rfmri; index finger; little finger
Journal Title: Brain Connectivity
Volume: 8
Issue: 6
ISSN: 2158-0014
Publisher: Mary Ann Liebert, Inc  
Date Published: 2018-08-01
Start Page: 371
End Page: 379
Language: English
DOI: 10.1089/brain.2018.0589
PROVIDER: scopus
PMCID: PMC6103248
PUBMED: 29987948
DOI/URL:
Notes: Article -- Export Date: 1 October 2018 -- Source: Scopus
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MSK Authors
  1. Robert J Young
    106 Young
  2. Sasan Karimi
    93 Karimi
  3. Kyung Peck
    77 Peck
  4. Andrei Holodny
    135 Holodny
  5. Mehrnaz Jenabi
    6 Jenabi
  6. Behroze Adi Vachha
    10 Vachha