This document discusses myoclonus, which are sudden, brief involuntary muscle jerks. It describes the different types of myoclonus including positive vs negative and cortical vs subcortical. Various potential causes are outlined such as neurological disorders, metabolic conditions, infections, and medications. Treatment options mentioned include anticonvulsant medications and deep brain stimulation.

1. Myoclonus
AdeWijaya, MD – November 2019

2. Introduction
• Sudden, brief, shock-like involuntary movements, associated
with bursts of muscular activity (positive myoclonus) or
silencing of muscular activity (negative myoclonus)
• It may be present at rest, during voluntary movement (action-
induced) or due to provoking stimuli such as sensory, visual,
auditory or emotional cues
• Typically, myoclonus presents as short (10–50 ms, rarely more
than 100 ms), non-rhythmic jerks, often without any
discernible pattern
Caviness, J.N. Myoclonus. Mayo Clin. Proc. 1996, 71, 679–688.
Shibasaki, H. Neurophysiological classification of myoclonus. Neurophysiol. Clin. 2006, 36, 267–269

3. Epidemiology
• The average annual incidence: 1 per 100,000 person-years
• Lifetime prevalence: less than 10 cases per 100,000 population
• The rate increased with advancing age and was consistently
higher in men
• Neurodegenerative and dementing diseases were the most
common cause of symptomatic myoclonus (about 70%)
Caviness, J.N.; Alving, L.I.; Maraganore, D.M.; Black, R.A.; McDonnell, S.K.; Rocca, W.A. The incidence and prevalence of myoclonus in olmsted county, minnesota. Mayo Clin. Proc. 1999, 74, 565–569.
Caviness, J.N.; Brown, P. Myoclonus: Current concepts and recent advances. Lancet Neurol. 2004, 3, 598–607.

4. Classification
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

5. Cortical Myoclonus
• Myoclonus in the Context of Epilepsy
• Neurodegenerative and Mitochondrial Disorders
• Cerebrovascular Disease with Probable Cortical Sources
• Acute post-hypoxic myoclonus
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

6. Subcortical Myoclonus
• Myoclonus Dystonia
• Orthostatic Myoclonus
• Chronic Posthypoxic Myoclonus
• Cerebrovascular Disease with Probable Subcortical Sources
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

7. Others
• Segmental and Peripheral Myoclonus
• Propriospinal Myoclonus
• Negative Myoclonus
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

8. Metabolic Causes of Myoclonus
• Uremic encephalopathy
• Hepatic encephalopathy
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

9. Autoimmune Conditions with Myoclonus
• Opsoclonus-Myoclonus Syndrome
• Steroid-Responsive Encephalopathy with Autoimmune
Thyroid Disease
• Stiff-Person Syndrome and Progressive Encephalomyelitis
with Rigidity
• Limbic encephalitis
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

10. Infectious und Para-Infectious Causes of
Myoclonus
• HIV infection
• Whipple disease
• Viral (VZV, HSV-1, EBV, measles, mumps, WNV, St. Louis
encephalitis, EEE (Eastern equine encephalitis) virus,WEE
(Western equine encephalitis) virus, Dengue virus), bacterial
(Leptospira, Mycoplasma pneumonia), parasitic (cerebral
malaria) or slow virus infections (subacute sclerosing
panencephalitis)
Cardoso, F. Hiv-related movement disorders: Epidemiology, pathogenesis and management. CNS Drugs 2002, 16, 663–668.
Louis, E.D.; Lynch, T.; Kaufmann, P.; Fahn, S.; Odel, J. Diagnostic guidelines in central nervous system whipple’s disease. Ann. Neurol. 1996, 40, 561–568.
Zutt, R.; van Egmond, M.E.; Elting, J.W.; van Laar, P.J.; Brouwer, O.F.; Sival, D.A.; Kremer, H.P.; de Koning, T.J.; Tijssen, M.A. A novel diagnostic approach to patients with myoclonus. Nat. Rev. Neurol. 2015, 11, 687–697.

11. Medication andToxin-Induced Myoclonus
• Opioids
• Antidepressants
• Classic or atypical antipsychotics
• Antiepileptic drugs
• Antibiotics
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

12. Treatment
• Cortical myoclonus: levetiracetam, valproic acid, clonazepam
or piracetam
• Subcortical myoclonus: clonazepam
• Deep brain stimulation
Eberhardt O, Topka H. Myoclonic disorders. Brain sciences. 2017 Aug;7(8):103.

13. Summary
• Sudden, brief, shock-like involuntary movements
• Positive vs negative myoclonus
• Cortical vs subcortical myoclonus
• Various etiologies
• Treatment: anticonvulsants; deep brain stimulation

14. THANKYOU