Myoclonus involves rapid, involuntary, irregular jerking movements that cannot be consciously suppressed. It may arise in a wide range of conditions.
Metabolic encephalopathy:
(1) post-hypoxic encephalopathy
(2) electrolyte imbalance
(3) hepatic failure
(4) renal failure
(5) hypoglycaemia
(6) hyperthyroidism
Drugs and toxins:
(1) narcotics
(2) antiarrhythmics
(3) psychiatric medication
(4) lithium
(5) antibiotics
(6) L-dopa
(7) amantadine
(8) marijuana
(9) heavy metals
(10) strychnine
Physical encephalopathy:
(1) post-traumatic
(2) sunstroke
Paraneoplastic encephalopathy
Infectious/post-infectious encephalitis:
(1) herpes simplex virus (HSV)
(2) AIDS
(3) subacute sclerosing panencephalitis (SSPE)
Dementia:
(1) Creutzfeld-Jakob disease
(2) Alzheimer disease
(3) frontotemporal dementia
(4) Lewy body dementia
Basal ganglia and spinocerebellar degeneration:
(1) Huntington’s disease
(2) Parkinson’s disease
(3) progressive supranuclear paralysis (PSP)
(4) multiple system atrophy (MSA)
(4) Friedreich’s ataxia
(5) spinocerebellar ataxia (SCA1, SCA2)
(6) Wilson’s disease
Lipid storage disease:
(1) Lafora body disease
(2) Tay-Sachs disease
(3) GM2 gangliosidosis
Focal central nervous system lesions
Epileptic syndromes:
(1) childhood myoclonic epilepsy
(2) epileptic myoclonic jerks
(3) infantile spasms
(4) epilepsia partialis continua
(5) photosensitive myoclonus
Essential myoclonus:
(1) hereditary
(2) sporadic
(3) myoclonus-dystonia
Physiological myoclonus:
(1) sleep jerks
(2) exercise
(3) hiccup
