Please read this and see my comments on the end of the article.
Myoclonus
Treatment
The most important step in treating myoclonus is to first identify and appropriately classify the subtype of the disorder because the pathology—and, therefore, treatments and outcomes—are cause specific in many cases. Before proceeding to therapy, it is essential to treat any underlying conditions, such as metabolic derangements and toxin or drug exposures that have led to the disorder. In many cases, treatment is not necessary; however, when myoclonus interferes with quality of life and activities of daily living, a number of therapies are available. The mainstay of treatment is with pharmacologic agents, but in specific circumstances, chemodenervation with botulinum toxin injection therapy, immunomodulatory therapy, and surgical interventions are warranted.
Pharmacologic Agents
Few randomized, double-blind, placebo-controlled trials have been conducted on the effects of antimyoclonic drugs, and although clonazepam and valproic acid are often used in the treatment of myoclonus, they have never been formally studied for this use. Expert opinion forms the basis for the use of most drugs in treating myoclonus. The guiding principles in the pharmacologic treatment of myoclonus are (1) to recognize that therapy is empiric, targeted at symptom relief, and (2) that, although polytherapy is often required, treatment should be instituted with a single drug. The choice of drugs is based upon the answers to questions identified in the diagnostic approach—the fundamental cause and origin of the movements—and the side-effect profile of the agents. The primary drugs used to treat myoclonus include levetiracetam (Keppra®), clonazepam (Klonopin®), valproic acid (Depakote®, Depakene®), primidone (Myidone®, Mysoline®), piracetam (Nootrypl®), and acetazolamide (AK-Zol®, Diamox®).
Primary Pharmacologic Agents: Levetiracetam
Levetiracetam (Keppra®), a pyrrolidone derivative, has been shown in open-label trials and multiple case reports to have antimyoclonic activity.1-9 Because this drug is well tolerated, has no interaction with other drugs, does not require titration, and is not metabolized but is excreted unchanged in the urine, a trial is warranted in most patients with myoclonus, particularly those with proven posthypoxic cortical myoclonus.
Types of myoclonus in which levetiracetam may be useful
•Cortical1-3◦Lance Adams syndrome2-4
◦Postencephalitic myoclonus4
◦PME,2,5,6
◦Creutzfeldt-Jakob disease7
•Paraneoplastic2
•Negative8
•Spinal9
Mechanism of action
•Unknown, but does not appear to derive its benefit from any interaction with known mechanisms involved in inhibitory and excitatory neurotransmission.
Adverse reactions
•Asthenia
•Headache
•Somnolence
•Dizziness
Cautions
•Dosage should be adjusted based on renal function
•Should be used with caution in the elderly
Comment:
I have had several patients on this. Some don’t tolerate it well. Its just another bandaid that is a temporary solution that many really don’t find changes the myoclonus significantly.
John Lieurance, D.C.
