Laboratory Studies

Complete blood count, chemistry, creatine kinase, thyroid testing group, sedimentation rate, Lyme titer, Venereal Disease Research Laboratory (VDRL) test, and rheumatology screening are the basic laboratory tests for all patients with clinical myokymia. Serum alcohol level and toxic screen are recommended for acute onset of generalized myokymia.

Imaging Studies

Neuroimaging studies with CT scan or MRI usually are performed for certain regions after careful examination and in cases in which electrodiagnostic studies have localized a lesion to a particular area. For example, if facial myokymia is confirmed, MRI study of the brain with special attention to posterior fossa is ordered to search for an anatomic lesion. Imaging studies are not otherwise necessary for establishing the diagnosis of myokymia.

Other Tests

Nerve conduction velocity (NCV) and EMG studies are necessary to qualify and quantify neurogenic/myogenic dysfunction.

NCV can detect the presence of plexopathy, mononeuropathy, and polyneuropathy (axonal or demyelinating).
EMG can confirm the presence of myokymic discharges or neuromyotonia. The specific findings of myokymia in EMG examination are detailed in the Physical section.
EMG study also can document the presence of neurogenic/myogenic dysfunction and its distribution.
Information obtained through these studies serves as a guide for further diagnostic investigation. Serial studies can objectively document the evolution of the myokymia.

Procedures

Lumbar puncture with examination of cerebrospinal fluid (CSF) usually is performed for patients with documented acute or chronic polyradiculoneuropathy, central nervous system demyelinating disorder, or other suspected inflammatory, infectious, or neoplastic processes.

Treatment & Management

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Author

Suying L Song, MD Assistant Clinical Professor of Neurology, New York University School of Medicine

Suying L Song, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Neil A Busis, MD Chief of Neurology and Director of Neurodiagnostic Laboratory, UPMC Shadyside; Clinical Professor of Neurology and Director of Community Neurology, Department of Neurology, University of Pittsburgh Physicians

Neil A Busis, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: American Academy of Neurology<br/>Serve(d) as a speaker or a member of a speakers bureau for: American Academy of Neurology<br/>Received income in an amount equal to or greater than $250 from: American Academy of Neurology.

Chief Editor

Nicholas Lorenzo, MD, CPE, MHCM, FAAPL Co-Founder and Former Chief Publishing Officer, eMedicine and eMedicine Health, Founding Editor-in-Chief, eMedicine Neurology; Founder and Former Chairman and CEO, Pearlsreview; Founder and CEO/CMO, PHLT Consultants; Former Chief Medical Officer, MeMD Inc

Nicholas Lorenzo, MD, CPE, MHCM, FAAPL is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, American Association for Physician Leadership

Disclosure: Nothing to disclose.

Additional Contributors

Carmel Armon, MD, MSc, MHS Chair, Department of Neurology, Assaf Harofeh Medical Center, Tel Aviv University Sackler Faculty of Medicine, Israel

Carmel Armon, MD, MSc, MHS is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Association of Neuromuscular and Electrodiagnostic Medicine, American Clinical Neurophysiology Society, American College of Physicians, American Epilepsy Society, American Medical Association, American Neurological Association, American Stroke Association, Massachusetts Medical Society, Sigma Xi, The Scientific Research Honor Society

Disclosure: Received research grant from: Neuronix Ltd, Yoqnea'm, Israel<br/>Received income in an amount equal to or greater than $250 from: JNS - Associate Editor. UpToDate - Author Royalties.