PRESENTED BY MATTHEW EBRIGHT PGY-2

MYOCLONUS - OUTLINE
Definition
Pathophysiology
Classification
Etiologies
Specific Examples
Evaluation
Treatment
Videos

DEFINE MYOCLONUS
What is it?
• Rapid
• Brief
• Involuntary
• Contraction
• One or multiple muscles, around a joint
• Symmetry?
• Synchrony?
Differential Diagnosis?

PATHOPHYSIOLOGY
Not entirely clear!
• Reduced intracortical inhibition
• Hyper-excitable sensorimotor cortex
• Cerebellar degeneration
• Striatal lesions

HOW TO CLASSIFY
MYOCLONUS
1.
Anatomic localization
2.
Time course
3.
Triggers
4.
Other general clinical features

HOW TO CLASSIFY
MYOCLONUS
1.
Anatomic localization
2.
Time course
3.
Triggers
4.
Other general clinical features

LOCALIZATION
Is it…
• Focal
• Segmental
• Multi-focal
• Diffuse/generalized

LOCALIZATION
Cortical
• Diffuse vs focal
• Sensorimotor cortex
Subcortical
• Cortical-subcortical and subcortical-nonsegmental
Segmental
• Brainstem
• Spine

HOW TO CLASSIFY
MYOCLONUS
1.
Anatomic localization
2.
Time course
3.
Triggers
4.
Other general clinical features

TIME COURSE
Non-progressive
• Spinal, benign rolandic epilepsy, JME, post-hypoxic, iatrogenic, metabolic
Progressive
• Neurodegenerative, epilepsia partialis continua
Rapid onset or progression
• CJD, SSPE, post-infectious, anti-NMDA, metabolic, psychogenic

HOW TO CLASSIFY
MYOCLONUS
1.
Anatomic localization
2.
Time course
3.
Triggers
4.
Other general clinical features

TRIGGERS
1.
Spontaneous
2.
Action-induced
3.
Sensory-induced

HOW TO CLASSIFY
MYOCLONUS
1.
Anatomic localization
2.
Time course
3.
Triggers
4.
Other general clinical features

CLINICAL GROUPING

PRIMARY MYOCLONUS
• Physiologic
• Essential/hereditary
• Myoclonus-dystonia syndrome
• Hyperekplexia
• Epileptic
• EPC, benign rolandic epilepsy, juvenile myoclonic epilepsy, familial cortical tremor with epilepsy
• Primary progressive myoclonus of aging

SECONDARY MYOCLONUS
• Progressive myoclonic encephalopathies and storage diseases
•
Lafora body
• MERRF
• Lipofuscinosis
•
Unverricht disease
• Ramsay Hunt
• Krabbe
• Tay Sachs
• Sandhoff
•
Sialidosis (cherry-red spot myoclonus)
• Gaucher type III
• Dentatorubrual-pallidoluysian atrophy

SECONDARY MYOCLONUS
• Neurodegenerative diseases
• Alzheimer dementia
• Parkinson disease
• Dementia with Lewy bodies
• Corticobasal degeneration
• Multiple system atrophy
• Frontotemporal dementia

SECONDARY MYOCLONUS
• Infectious/Inflammatory
• Encephalitis (NMDA encephalitis)
• Post-infectious
• SSPE
• Opsoclonus-myoclonus syndrome

SECONDARY MYOCLONUS
• Metabolic
• Liver, renal, dialysis, sodium, glucose, Celiac, Whipples
• Drugs/Toxins
• Anti-convulsants, anti-psychotics, anesthetics, morphine, levodopa, contrast, heavy metals
• Nervous System Damage
• Post-hypoxic, traumatic, stroke, spinal cord lesions, demyelinating disease
• Psychogenic

SPECIFIC EXAMPLES
• Myoclonus-dystonia
• Syndrome of essential myoclonus
• Action-induced multifocal myoclonus
• Cervical dystonia or writer’s cramp
• Autosomal dominant
• Alcohol-responsive

SPECIFIC EXAMPLES
• Post-Hypoxic Myoclonus (Lance-Adams Syndrome)
• Subcortical, multifocal
• Action-induced, exquisitely
• Days to weeks after recovery

SPECIFIC EXAMPLES
• Neurodegenerative Diseases
• PD – levodopa, amantadine, severe late disease
• Corticobasal degeneration – action induced and stimulus sensitive
• MSA – low-amplitude, irregular, arrhythmic, hands and fingers, face
• LBD
• CJD – aggressive, progressively multifocal

SPECIFIC EXAMPLES
• Opsoclonus-myoclonus ataxia syndrome
• Chaotic myoclonic eye movements
• Oscillopsia
• Multifocal, action-related myoclonus
• Paraneoplastic or post-infectious

SPECIFIC EXAMPLES
• Hyperekplexia
• Autosomal dominant
• Stiff babies
• Episodic tonic spasms
• Nocturnal myoclonus
• Exaggerated startle responses
• Brainstem localization
• Non-habituating
• Overly-sensitive to stimuli
• May persist through life

SPECIFIC EXAMPLES
• Canine myoclonus
• Distemper - RNA virus
• Multi-system disease
• Encephalomyelitis
• Myoclonus, seizures, rapid neurodegeneration

EVALUATION
• Localize!
• Labs, CSF?
• Imaging
• EMG
• EEG-EMG

TREATMENT

Opsoclonus-Myoclonus https://www.youtube.com/watch?v=zX4j0IsFbAk
Propriospinal Myoclonus https://www.youtube.com/watch?v=W15D8N0wlyY
Generalized Myoclonus in SSPE https://www.youtube.com/watch?v=pfCQP7IL2XY
Myoclonic Dystonia http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4s/ permalink/cont/a/cont_19_5_2013_08_08_zadikoff_190510_sdc3.mp4
Post-hypoxic Myoclonus (Lance-Adams) http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4s/ permalink/cont/a/cont_19_5_2013_08_08_espay_190510_sdc4.mp4
Amantadine-induced http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4s/ permalink/cont/a/cont_19_5_2013_08_08_espay_190510_sdc6.mp4
and http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4s/ permalink/cont/a/cont_19_5_2013_08_08_espay_190510_sdc7.mp4

VIDEOS
Corticobasal Degeneration http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4 s/permalink/cont/a/cont_19_5_2013_08_08_duker_190510_sdc11.mp4
Unverricht-Lundborg http://wolterskluwer.http.internapcdn.net/wolterskluwer_vitalstream_com/MP4 s/permalink/cont/a/cont_19_5_2013_08_08_morgante_190510_sdc12.mp4
Hyperekplexia http://www.dailymail.co.uk/health/article-2767882/The-fathers-literally-scared-STIFF-time-s-startled-sudden-noise-taken-surprise.html
Focal Cortical Myoclonus https://www.youtube.com/watch?v=BHeCok19jWo
Palatal Myoclonus – https://www.youtube.com/watch?v=GlnxI93PrMM
Canine Myoclonus – https://www.youtube.com/watch?v=MHQhoH5gYWo

IN SUMMARY
Myoclonus:
History
Exam
Localize
Time course
Clinical features
Diagnostics
Treat
Neurology all in one special!