Treatment of Myoclonus

Abstract

Myoclonus creates significant disability for patients. This symptom or sign can have many different etiologies, presentations, and pathophysiological mechanisms. A thorough evaluation for the myoclonus etiology is critical for developing a treatment strategy. The best etiological classification scheme is a modified version from that proposed by Marsden et al. in 1982. Clinical neurophysiology, as assessed by electromyography and electroencephalography, can be used to classify the pathophysiology of the myoclonus using a neurophysiology classification scheme. If the etiology of the myoclonus cannot be reversed or treated, then symptomatic treatment of the myoclonus itself may be warranted. Unfortunately, there are few controlled studies for myoclonus treatments. The treatment strategy for the myoclonus is best derived from the neurophysiology classification scheme categories: 1) cortical, 2) cortical-subcortical, 3) subcorticalnonsegmental, 4) segmental, and 5) peripheral. A cortical physiology classification is most common. Levetiracetam is suggested as first-line treatment for cortical myoclonus, but valproic acid and clonazepam are commonly used. Corticalsubcortical myoclonus is the physiology demonstrated by myoclonic seizures, such as in primary epileptic myoclonus (e.g., juvenile myoclonic epilepsy). Valproic acid has demonstrated efficacy in such epileptic syndromes with other medications providing an adjunctive role. Clonazepam is used for subcortical-nonsegmental myoclonus, but other treatments, depending on the syndrome, have been used for this physiological type of myoclonus. Segmental myoclonus is difficult to treat, but clonazepam and botulinum toxin are used. Botulinum toxin is used for focal examples of peripheral myoclonus. Myoclonus treatment is commonly not effective and/or limited by side effects.

Analyzing reliability of seizure diagnosis based on semiology

“…The myoclonic seizure is very brief and easy to miss. Moreover, it is also similar to nonepileptic myoclonic jerks occur in physiological or pathological conditions [15].…”

Nasal pregabalin overdose and myclonus: a new way of misuse

“…There are various causes of myoclonus and pathophysiological mechanisms associated with this symptom [4,5]. Metabolic and toxic etiologies such as renal/hepatic failure, hyponatremia, hypoglycemia, hyperthyroidism, head trauma can cause myoclonus.…”

Review of Sodium Valproate Clinical and Biochemical Properties

“…Lamotrigine can be used either alone or in combination with VPA. Leveti-racetam or zonisamide can also be used as adjunct therapy with VPA [14,15]. The risk of seizures differs between 60% and 100% with low grade gliomas and between 40% and 60% in glioblastomas.…”