Anatomic and physiologic classification of common types of myoclonus*

Cortical

Asterixis (some cases)

Epilepsia partialis continua

Cortical reflex myoclonus

Cortical myoclonus without exaggerated reflex features

Certain drug-induced and toxic-metabolic etiologies of myoclonus

Neurodegenerative disease with cortical involvement:

- Alzheimer disease

- Corticobasal degeneration

- Creutzfeldt-Jakob disease

- Huntington disease

- Parkinson disease and other Lewy body disorders

Posthypoxic action myoclonus (Lance-Adams myoclonus)

Progressive myoclonic ataxias

Progressive myoclonic epilepsies

Cortical-subcortical

Absence seizures

Primary generalized epileptic myoclonus

Primary generalized myoclonic seizures

Subcortical-nonsegmental

Essential myoclonus (hereditary)

Hyperekplexia

Opsoclonus-myoclonus syndrome

Propriospinal myoclonus

Reticular reflex myoclonus

Segmental

Palatal myoclonus

Segmental spinal myoclonus

Peripheral

Hemifacial spasm

* More than one mechanism may be operative in an individual patient or disease.

Modified from: Caviness JN, Brown P. Myoclonus: current concepts and recent advances. Lancet Neurol 2004; 3:598.

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