Increased EMG intermuscular coherence and reduced signal complexity in Parkinson’s disease

Flood, Matthew W.; Jensen, Bente Rona; Malling, Anne Sofie Bøgh; Lowery, Madeleine M.

doi:10.1016/j.clinph.2018.10.023

Cited by 38 publications

(33 citation statements)

References 47 publications

(75 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All participants understood the task and scored >23 on the mini mental status exam. Our sample size is intended to be sufficient for detection of large differences and correlations, and is in line with similar recent literature [e.g., Flood et al, (11)] where such effects were found.…”

Section: Participantssupporting

confidence: 52%

“…While elevated intermuscular coherence between anatomicallysynergistic muscles has been found during static voluntary tasks in PD (7,11), these findings may not extend to dynamic actions, or to functionally-different muscles whose coordination can change depending on task.…”

Section: Introductionmentioning

confidence: 71%

“…Tremor at rest (rest tremor) typically has a frequency of ∼3-6 Hz, while "action tremor" extends from ∼6-15 Hz and occurs during voluntary static (postural action tremor) or dynamic (kinetic action tremor) muscle activation (1)(2)(3)(4)(5)(6). Further, PD is associated with increased corticomuscular drive in the range of 15-30 Hz during static contractions (7)(8)(9)(10)(11), as well as reduced neural drive to muscles in the 30-50 Hz range in unmedicated patients (12).…”

Section: Introductionmentioning

confidence: 99%

“…Our primary hypotheses were that (1) intermuscular coherence would be larger in PD, especially at ∼10 Hz during both dynamic tasks, (2) the task-dependent modulation of intermuscular coherence seen in controls would be preserved in PD, and (3) the amplification of alpha-band coherence would correlate with clinical severity, since dynamic tasks should preferentially utilize neural pathways known to deliver alphaband drive to muscles, and which are known to be disrupted in PD, such as the cerebello-thalamo-cortical circuit (30,(40)(41)(42). Given that intermuscular coherence analysis has been suggested as a potential avenue for biomarker development (11), and that we lack simple, cost-effective methods for detecting the presence of PD and the severity of neural damage, a secondary aim was to determine the ability of coherence measures to discriminate between PD and control groups, as this would justify future efforts to develop clinically-applicable metrics using EMG.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Parkinson's Disease Exhibits Amplified Intermuscular Coherence During Dynamic Voluntary Action

Laine

Valero-Cuevas

2020

Front. Neurol.

View full text Add to dashboard Cite

Parkinson's disease (PD) is typically diagnosed and evaluated on the basis of overt motor dysfunction, however, subtle changes in the frequency spectrum of neural drive to muscles have been reported as well. During dynamic actions, coactive muscles of healthy adults often share a common source of 6-15 Hz (alpha-band) neural drive, creating synchronous alpha-band activity in their EMG signals. Individuals with PD commonly exhibit kinetic action tremor at similar frequencies, but the potential relationship between the intermuscular alpha-band neural drive seen in healthy adults and the action tremor associated with PD is not well-understood. A close relationship is most tenable during voluntary dynamic tasks where alpha-band neural drive is strongest in healthy adults, and where neural circuits affected by PD are most engaged. In this study, we characterized the frequency spectrum of EMG synchronization (intermuscular coherence) in 16 participants with PD and 15 age-matched controls during two dynamic motor tasks: (1) rotation of a dial between the thumb and index finger, and (2) dynamic scaling of isometric precision pinch force. These tasks produce different profiles of coherence between the first dorsal interosseous and abductor pollicis brevis muscles. We sought to determine if alpha-band intermuscular coherence would be amplified in participants with PD relative to controls, if such differences would be task-specific, and if they would correlate with symptom severity. We found that relative to controls, the PD group displayed amplified, but similarly task-dependent, coherence in the alpha-band. The magnitude of coherence during the rotation task correlated with overall symptom severity as per the UPDRS rating scale. Finally, we explored the potential for our coherence measures, with no additional information, to discriminate individuals with PD from controls. The area under the Receiver Operating Characteristic curve (AUC) indicated a clear separation between groups (AUC = 0.96), even though participants with PD were on their typical medication and displayed only mild-moderate symptoms. We conclude that a task-dependent, intermuscular neural drive within the alpha-band is amplified in PD. Its quantification via intermuscular coherence analysis may provide a useful tool for detecting the presence of PD, or assessing its progression.

show abstract

Section: Participantssupporting

confidence: 52%

Section: Introductionmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Parkinson's Disease Exhibits Amplified Intermuscular Coherence During Dynamic Voluntary Action

Laine

Valero-Cuevas

2020

Front. Neurol.

View full text Add to dashboard Cite

show abstract

“…Priori et al 44 reported a change of lower frequency bands (2-7 Hz, alpha (7-13 Hz) and beta (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) Hz)) of the local field potential (LFP) of the subthalamic nucleus (STN) in the course of deep brain stimulation (DBS) in off and on medication state in PD patients. Thereby, the low frequency (2-7 Hz) activity increased after levodopa administration, whereas the low beta (13)(14)(15)(16)(17)(18)(19)(20) Hz) activity decreased in the on-state 44 .…”

Section: Discussionmentioning

confidence: 99%

Parkinson patients without tremor show changed patterns of mechanical muscle oscillations during a specific bilateral motor task compared to controls

Schaefer

Bittmann

2020

Sci Rep

View full text Add to dashboard Cite

the pathophysiology of parkinson's disease (pD) is still not understood. there are investigations which show a changed oscillatory behaviour of brain circuits or changes in variability of, e.g., gait parameters in PD. The aim of this study was to investigate whether or not the motor output differs between PD patients and healthy controls. Thereby, patients without tremor are investigated in the medication off state performing a special bilateral isometric motor task. The force and accelerations (ACC) were recorded as well as the Mechanomyography (MMG) of the biceps brachii, the brachioradialis and of the pectoralis major muscles using piezoelectric-sensors during the bilateral motor task at 60% of the maximal isometric contraction. The frequency, a specific power ratio, the amplitude variation and the slope of amplitudes were analysed. The results indicate that the oscillatory behaviour of motor output in PD patients without tremor deviates from controls: thereby, the 95%-confidence-intervals of power ratio and of amplitude variation of all signals are disjoint between PD and controls and show significant differences in group comparisons (power ratio: p = 0.000-0.004, r = 0.441-0.579; amplitude variation: p = 0.000-0.001, r = 0.37-0.67). The mean frequency shows a significant difference for ACC (p = 0.009, r = 0.43), but not for MMG. It remains open, whether this muscular output reflects changes of brain circuits and whether the results are reproducible and specific for PD.The pathogenesis and pathomechanism of Parkinson's disease (PD) are not clarified yet 1-4 . A damage or death of neuronal cells through aggregation of misfolded alpha-synuclein in Lewy bodies is reported to be necessary 5,6 . The occurrence of those Lewy bodies in PD are reported for brain and other nerval structures as the spinal cord, peripheral nervous system, cervical sympathetic trunk and vagal nerve 6 , but also for the submandibular gland or the upper gastrointestinal tract 4 . The misfolded alpha-synuclein spread in diverse cells and lead to several deficits of bodily functions as e.g. mitochondrial function 5,6 . However, also other proteins than alpha-synuclein and other pathological changes are discussed to be relevant in PD 6,7 . This emphasises the complexity of PD and explains the different symptom appearances in patients, which complicates the diagnosis.PD is characterized by the presence of multiple motor and nonmotor symptoms 1,6,7 . The motor symptoms are not limited to tremor, but also appear as postural instability or gait impairment 6,8,9 . In addition, the tremor appears not only as resting tremor, but also as holding or postural tremor 10 . The motor symptoms are primarily explained by the loss of dopaminergic cells in the substantia nigra 2,5-7 . If the motor stage is reached, already around 50% of the dopaminergic neurons of the total substantia nigra are lost 11,12 and around 80% of the striatal dopamine is reduced [12][13][14] . If the amount of loss is lower, the patients are in the so called premotor state. Especial...

show abstract

Deep Brain Stimulation for Orthostatic Tremor: An Observational Study

Babeliowsky,

Bot,

Potters

et al. 2024

Movement Disord Clin Pract

View full text Add to dashboard Cite

BackgroundPrimary orthostatic tremor (OT) can affect patients’ life. Treatment of OT with deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (Vim) is described in a limited number of patients. The Vim and posterior subthalamic area (PSA) can be targeted in a single trajectory, allowing both stimulation of the Vim and/or dentatorubrothalamic tract (DRT). In essential tremor this is currently often used with positive effects.ObjectiveTo evaluate the efficacy of Vim/DRT‐DBS in OT‐patients, based on standing time and Quality of Life (QoL), also on the long‐term. Furthermore, to relate stimulation of the Vim and DRT, medial lemniscus (ML) and pyramidal tract (PT) to beneficial clinical and side‐effects.MethodsNine severely affected OT‐patients received bilateral Vim/DRT‐DBS. Primary outcome measure was standing time; secondary measures included self‐reported measures, neurophysiological measures, structural analyses, surgical complications, stimulation‐induced side‐effects, and QoL up to 56 months. Stimulation of volume of tissue activated (VTA) were related to outcome measures.ResultsAverage maximum standing time increased from 41.0 s ± 51.0 s to 109.3 s ± 65.0 s after 18 months, with improvements measured in seven of nine patients. VTA (n = 7) overlapped with the DRT in six patients and with the ML and/or PT in six patients. All patients experienced side‐effects and QoL worsened during the first year after surgery, which improved again during long‐term follow‐up, although remaining below age‐related normal values. Most patients reported a positive effect of DBS.ConclusionVim/DRT‐DBS improved standing time in patients with severe OT. Observed side‐effects are possibly related to stimulation of the ML and PT.

show abstract

Increased EMG intermuscular coherence and reduced signal complexity in Parkinson’s disease

Cited by 38 publications

References 47 publications

Parkinson's Disease Exhibits Amplified Intermuscular Coherence During Dynamic Voluntary Action

Parkinson's Disease Exhibits Amplified Intermuscular Coherence During Dynamic Voluntary Action

Parkinson patients without tremor show changed patterns of mechanical muscle oscillations during a specific bilateral motor task compared to controls

Deep Brain Stimulation for Orthostatic Tremor: An Observational Study

Contact Info

Product

Resources

About