Altered activation and connectivity of the supplementary motor cortex at motor initiation in Parkinson's disease patients with freezing.
Clin Neurophysiol
; 131(9): 2171-2180, 2020 09.
Article
in En
| MEDLINE
| ID: mdl-32683125
OBJECTIVE: Motor initiation failure is a key feature of freezing of gait (FOG) due to Parkinson's disease (PD). The supplementary motor cortex (SMC) plays a central role in its pathophysiology. We aimed at investigating SMC activation, connectivity and plasticity with regard to motor initiation in FOG. METHODS: Twelve patients with FOG and eleven without FOG underwent a multimodal electrophysiological evaluation of SMC functioning including the Bereitschaftspotential and movement-related desynchronisation of cortical beta oscillations. SMC plasticity was modulated by intermittent theta burst stimulation (iTBS) and its impact on gait initiation was assessed by a three-dimensional gait analysis. RESULTS: Prior to volitional movements the Bereitschaftspotential was smaller and beta power was less strongly attenuated over the SMC in patients with FOG compared to those without. Pre-motor coherence between the SMC and the primary motor cortex in the beta frequency range was also stronger in patients with FOG. iTBS resulted in a relative deterioration of gait initiation. CONCLUSIONS: Reduced activation of the SMC along with increased SMC connectivity in the beta frequency range hinder a flexible shift of the motor set as it is required for gait initiation. SIGNIFICANCE: Altered SMC functioning plays an important role for motor initiation failure in PD-related FOG.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parkinson Disease
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Contingent Negative Variation
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Gait Disorders, Neurologic
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Motor Cortex
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Movement
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Nerve Net
Limits:
Aged
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Female
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Humans
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Male
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Middle aged
Language:
En
Journal:
Clin Neurophysiol
Journal subject:
NEUROLOGIA
/
PSICOFISIOLOGIA
Year:
2020
Document type:
Article
Country of publication: