TY - JOUR
T1 - Tremor severity in Parkinson's disease and cortical changes of areas controlling movement sequencing
T2 - A preliminary study
AU - Benito-León, Julián
AU - Serrano, J. Ignacio
AU - Louis, Elan D.
AU - Holobar, Ales
AU - Romero, Juan P.
AU - Povalej-Bržan, P.
AU - Bermejo-Pareja, Félix
AU - del Castillo, M. Dolores
AU - Posada, Ignacio J.
AU - Rocon, Eduardo
N1 - Publisher Copyright:
© 2018 Wiley Periodicals, Inc.
PY - 2018/8
Y1 - 2018/8
N2 - There remains much to learn about the changes in cortical anatomy that are associated with tremor severity in Parkinson's disease (PD). For this reason, we used a combination of structural neuroimaging to measure cortical thickness and neurophysiological studies to analyze whether PD tremor was associated with cortex integrity. Magnetic resonance imaging and neurophysiological assessment were performed in 13 nondemented PD patients (9 women, 69.2%) with a clearly tremor-dominant phenotype. Cortical reconstruction and volumetric segmentation were performed with the Freesurfer image analysis software. Assessment of tremor was performed by means of high-density surface electromyography (hdEMG) and inertial measurement units (IMUs). Individual motor unit discharge patterns were identified from surface hdEMG and tremor metrics quantifying motor unit synchronization from IMUs. Increased motor unit synchronization (i.e., more severe tremor) was associated with cortical changes (i.e., atrophy) in wide-spread cortical areas, including caudal middle frontal regions bilaterally (dorsal premotor cortices), left inferior parietal lobe (posterior parietal cortex), left lateral orbitofrontal cortex, cingulate cortex bilaterally, left posterior and transverse temporal cortex, and left occipital lobe, as well as reduced left middle temporal volume. Given that the majority of these areas are involved in controlling movement sequencing, our results support Albert's classic hypothesis that PD tremor may be the result of an involuntary activation of a program of motor behavior used in the genesis of rapid voluntary alternating movements.
AB - There remains much to learn about the changes in cortical anatomy that are associated with tremor severity in Parkinson's disease (PD). For this reason, we used a combination of structural neuroimaging to measure cortical thickness and neurophysiological studies to analyze whether PD tremor was associated with cortex integrity. Magnetic resonance imaging and neurophysiological assessment were performed in 13 nondemented PD patients (9 women, 69.2%) with a clearly tremor-dominant phenotype. Cortical reconstruction and volumetric segmentation were performed with the Freesurfer image analysis software. Assessment of tremor was performed by means of high-density surface electromyography (hdEMG) and inertial measurement units (IMUs). Individual motor unit discharge patterns were identified from surface hdEMG and tremor metrics quantifying motor unit synchronization from IMUs. Increased motor unit synchronization (i.e., more severe tremor) was associated with cortical changes (i.e., atrophy) in wide-spread cortical areas, including caudal middle frontal regions bilaterally (dorsal premotor cortices), left inferior parietal lobe (posterior parietal cortex), left lateral orbitofrontal cortex, cingulate cortex bilaterally, left posterior and transverse temporal cortex, and left occipital lobe, as well as reduced left middle temporal volume. Given that the majority of these areas are involved in controlling movement sequencing, our results support Albert's classic hypothesis that PD tremor may be the result of an involuntary activation of a program of motor behavior used in the genesis of rapid voluntary alternating movements.
KW - Parkinson's disease tremor
KW - cortical thickness
KW - electromyography
KW - magnetic resonance imaging
UR - http://www.scopus.com/inward/record.url?scp=85045723666&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85045723666&partnerID=8YFLogxK
U2 - 10.1002/jnr.24248
DO - 10.1002/jnr.24248
M3 - Article
C2 - 29660812
AN - SCOPUS:85045723666
SN - 0360-4012
VL - 96
SP - 1341
EP - 1352
JO - Journal of Neuroscience Research
JF - Journal of Neuroscience Research
IS - 8
ER -