An Update on Myoclonus Management

ABSTRACT

Introduction: Myoclonus is a hyperkinetic movement disorder characterized by sudden, brief, lightning-like involuntary jerks. There are many possible causes of myoclonus and both the etiology and characteristics of the myoclonus are important in securing the diagnosis and treatment. Myoclonus may be challenging to treat, as it frequently requires multiple medications for acceptable results. Few randomized controlled trials investigating the optimal treatment for myoclonus are available, and expert experience and case series guide treatment.

Areas Covered: In this article, the authors review the basics of myoclonus and its classification. The authors discuss the current management of myoclonus and then focus on recent updates in the literature, including both pharmacologic and surgical options.

Expert opinion: Myoclonus remains a challenge to manage, and there is a paucity of rigorous clinical trials guiding treatment paradigms. Furthermore, due to the etiological heterogeneity of myoclonus, defining the appropriate scope for high-quality clinical trials is challenging. In order to advance the field, the myoclonus study group needs to be revived in the US and abroad so that interested investigators can collaborate on multicenter clinical trials for myoclonus treatments.

KEYWORDS:

• myoclonus
• treatment
• deep brain stimulation
• perampanel
• zonisamide

Article highlights

• Myoclonus is a hyperkinetic movement disorder characterized by sudden, brief, lightning-like involuntary jerks.

• The etiologies of myoclonus are diverse and are broadly grouped into four categories: physiologic, essential, epileptic, and symptomatic.

• Clinical and electrophysiologic characteristics of the myoclonic jerk help to further define and localize the anatomic origin of the myoclonus within the nervous system.

• Treatment of myoclonus begins with correcting or reversing the underlying pathology if possible, followed by pharmacologic and sometimes surgical treatment if the myoclonus remains. However, adequate treatment of myoclonus may be challenging, and commonly requires multiple agents to achieve even partial improvement.

• Zonisamide and perampanel have been shown in recent studies to improve myoclonus for some subtypes of the disorder.

• DBS has become an increasingly used treatment for myoclonus-dystonia with promising results. Emerging case reports suggest DBS may also be effective in treating posthypoxic myoclonus.

• There is a paucity of level I and II evidence supporting myoclonus treatment paradigms and more randomized controlled clinical trials are needed to advance our understanding of optimal treatment.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded