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Muscle Contraction01:10

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Updated: Sep 25, 2025

Corticospinal Excitability Modulation During Action Observation
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Speech-induced action myoclonus.

Hugh D Simpson1, Joseph R Duffy2, Julie A G Stierwalt2

  • 1Division of Movement Disorders, Department of Neurology, Mayo Clinic, Rochester, MN, USA.

Parkinsonism & Related Disorders
|April 25, 2022
PubMed
Summary
This summary is machine-generated.

Speech-induced action myoclonus, a rare condition causing facial twitching from speaking, is often misdiagnosed. Diagnostic tools like speech tasks and electrophysiology aid in identifying this challenging myoclonus syndrome.

Keywords:
Action myoclonusNeurophysiologySpeechSpeech therapy

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Area of Science:

  • Neurology
  • Movement Disorders
  • Clinical Electrophysiology

Background:

  • Speech-induced action myoclonus can be part of generalized myoclonus syndromes.
  • It may also present in isolation, posing diagnostic challenges due to limited associated findings.

Purpose of the Study:

  • To describe a retrospective case series focusing on restricted speech-induced action myoclonus.
  • To highlight diagnostic challenges and aids for this specific myoclonus presentation.

Main Methods:

  • Retrospective review of speech-induced action myoclonus cases at Mayo Clinic (1989-2020).
  • Exclusion of cases with generalized myoclonic disorders.
  • Extraction of clinical, imaging, and electrophysiologic data.

Main Results:

  • Four cases of predominant craniofacial speech-induced action myoclonus were identified.
  • Symptoms included cranial muscle twitching and speech interruptions; diagnosis confirmed by speech pathologists.
  • Diagnostic aids like speech task modulation and surface electrophysiology were utilized, revealing craniofacial myoclonus induced by speaking.
  • Previous misdiagnoses included functional disorders, dystonia, and hemifacial spasm.

Conclusions:

  • Speech-induced action myoclonus can occur in isolation and is prone to misdiagnosis.
  • Diagnostic aids such as varying speech tasks and surface electrophysiology are crucial for accurate diagnosis.