EMG coherence and spectral analysis in cervical dystonia: Discriminative tools to identify dystonic muscles?

Nijmeijer, S. W. R.; Bruijn, Edo de; Forbes, Patrick A.; Kamphuis, D. J.; Happee, Riender; Koelman, Johannes H. T. M.; Tijssen, Marina A. J.

doi:10.1016/j.jns.2014.09.041

Cited by 19 publications

(26 citation statements)

References 20 publications

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“…In line with previous studies [ 7 , 14 ], we found 8–14 Hz autospectral peaks in the SPL muscles of healthy controls, but not in CD patients. Several studies [ 7 , 14 , 15 ] have found evidence for synchronized activity at around 10–15 Hz in healthy neck muscles. These oscillations are hypothesized to facilitate common muscle synergies, and may originate from the reticular formation [ 15 , 16 ].…”

Section: Discussionsupporting

confidence: 93%

“…Blouin et al therefore proposed that voluntary cortical activation of the neck motor neurons occurs through a relay in the reticular formation instead of a direct corticospinal projection [ 15 ]. In line with previous studies [ 7 , 14 ] we were unable to observe the same 8–14 Hz peaks in the autospectra of SCM muscles, and they were less evident in SESP muscles. It is possible that during our specific isometric experiments, the SPL muscles but not the SCM muscles were recruited into muscle synergies facilitated by 8–14 Hz oscillations.…”

Section: Discussionsupporting

confidence: 92%

“…It can, however, not be excluded that the observed autospectral differences are the result of other factors like muscle atrophy caused by multiple BoNT injections, or the generally lower degrees of muscle contraction in patients (see limitations). Finally, we have considered the explanation that normal 8–14 Hz autospectral peaks are masked or suppressed by a more prominent dystonic drive in the 4–7 Hz frequency band, as previously described in dystonia patients [ 7 , 14 , 18 ]. However, this seems unlikely as no clear 4–7 Hz peaks were seen in the pooled autospectra of patients.…”

Section: Discussionmentioning

confidence: 99%

“…EMG activity around 4–7 Hz has frequently been described in dystonia patients reflecting a dystonic drive, probably originating from the basal ganglia [ 7 , 14 , 19 ]. This drive is mostly seen in patients with rhythmic EMG activity, or even a visible dystonic tremor [ 7 ]. In this study, CDF 10 values were indeed higher in most muscles in patients with tremor.…”

Section: Discussionmentioning

confidence: 99%

“…Unfortunately, no specific tools are available to reliably identify dystonic muscles, and discriminate them from healthy compensating muscles [ 6 ]. In a previous study we obtained intramuscular electromyography (EMG) recordings to investigate the autospectra of the EMG envelope and intermuscular coherences as possible discriminative tools to identify dystonic muscles [ 7 ]. The most discriminating finding was an 8–14 Hz autospectral peak that was measured in the splenius capitis (SPL) muscles of almost all healthy controls during isometric contraction, but that was absent in the majority of the dystonic SPL muscles in patients.…”

Section: Introductionmentioning

confidence: 99%

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Spectral EMG Changes in Cervical Dystonia Patients and the Influence of Botulinum Toxin Treatment

Nijmeijer

Bruijn

Verhagen

et al. 2017

Toxins

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Botulinum toxin (BoNT) injections in the dystonic muscles is the preferred treatment for Cervical Dystonia (CD), but the proper identification of the dystonic muscles remains a challenge. Previous studies showed decreased 8–14 Hz autospectral power in the electromyography (EMG) of splenius muscles in CD patients. Cumulative distribution functions (CDF’s) of dystonic muscles showed increased CDF10 values, representing increased autospectral powers between 3 and 10 Hz, relative to power between 3 and 32 Hz. In this study, we evaluated both methods and investigated the effects of botulinum toxin. Intramuscular EMG recordings were obtained from the splenius, semispinalis, and sternocleidomastoid muscles during standardized isometric tasks in 4 BoNT-naïve CD patients, 12 BoNT-treated patients, and 8 healthy controls. BoNT-treated patients were measured 4–7 weeks after their last BoNT injections and again after 11–15 weeks. We found significantly decreased 8–14 Hz autospectral power in splenius muscles, but not in the semispinalis and sternocleidomastoid muscles of CD patients when compared to healthy controls. CDF10 analysis was superior in demonstrating subtle autospectral changes, and showed increased CDF10 values in all studied muscles of CD patients. These results did not change significantly after BoNT injections. Further studies are needed to investigate the origin of these autospectral changes in dystonia patients, and to assess their potential in muscle selection for BoNT treatment.

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Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Spectral EMG Changes in Cervical Dystonia Patients and the Influence of Botulinum Toxin Treatment

Nijmeijer

Bruijn

Verhagen

et al. 2017

Toxins

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Isolated Cervical Dystonia: Diagnosis and Classification

et al. 2023

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This document presents a consensus on the diagnosis and classification of isolated cervical dystonia (iCD) with a review of proposed terminology. The International Parkinson and Movement Disorder Society Dystonia Study Group convened a panel of experts to review the main clinical and diagnostic issues related to iCD and to arrive at a consensus on diagnostic criteria and classification. These criteria are intended for use in clinical research, but also may be used to guide clinical practice. The benchmark is expert clinical observation and evaluation. The criteria aim to systematize the use of terminology as well as the diagnostic process, to make it reproducible across centers and applicable by expert and non‐expert clinicians. Although motor abnormalities remain central, increasing recognition has been given to nonmotor manifestations, which are incorporated into the current criteria. Three iCD presentations are described in some detail: idiopathic (focal or segmental) iCD, genetic iCD, and acquired iCD. The relationship between iCD and isolated head tremor is also reviewed. Recognition of idiopathic iCD has two levels of certainty, definite or probable, supported by specific diagnostic criteria. Although a probable diagnosis is appropriate for clinical practice, a higher diagnostic level may be required for specific research studies. The consensus retains elements proven valuable in previous criteria and omits aspects that are no longer justified, thereby encapsulating diagnosis according to current knowledge. As understanding of iCD expands, these criteria will need continuous revision to accommodate new advances. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

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Dystonia in Childhood: How Insights from Paediatric Research Enrich the Network Theory of Dystonia

McClelland

Lin

2023

Advances in Neurobiology

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EMG coherence and spectral analysis in cervical dystonia: Discriminative tools to identify dystonic muscles?

Cited by 19 publications

References 20 publications

Spectral EMG Changes in Cervical Dystonia Patients and the Influence of Botulinum Toxin Treatment

Spectral EMG Changes in Cervical Dystonia Patients and the Influence of Botulinum Toxin Treatment

Isolated Cervical Dystonia: Diagnosis and Classification

Dystonia in Childhood: How Insights from Paediatric Research Enrich the Network Theory of Dystonia

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