1. Dyskinesias in Children/Adolescents
CPT Timothy L. Switaj, MC, FS, USA
Neurology (Child) Intern

2. Objectives
To demonstrate the basic abnormal movements in children/adolescents
To begin to think about a differential for each type of movement
Brief discussion of the most likely etiologies of the abnormal movements

5. Basic Movement Types * Chorea/Athetosis Ballismus Dystonia
Hemifacial Spasm
Mirror Movements
* Myoclonus
Stereotypies
* Tics
* Tremor
Fasciculations
Myokymia
Seizures

6. Things to ask yourself when seeing patient
What does the movement look like?
Is it rhythmical, jerky or “dancelike”?
Can it be suppressed?
What medications is the patient taking?
Any Family History of similar movements?

7. General Characteristics (1)
Chorea/Athetosis – usually seen together
Chorea – rapid movement affecting body part that is incorporated into voluntary movement to hide it, NO FIXED FORM
Constant movement (restlessness)
Movements flow from side to side and limb to limb
Athetosis – slow, writhing movement of the limbs
Can occur alone but usually associated with chorea – athetosis without chorea is due to perinatal brain injury (most likely perinatal asphyxia)
Ballismus – high-amplitude, violent flinging of a limb (an extreme form of chorea)
Tardive Dyskinesia – uncommon in children

8. General Characteristics (2)
Dystonia – sustained muscle contractions
Can be focal, segmental, hemi or generalized
Hemifacial spasm – involuntary, irregular contraction of muscles innervated by one facial nerve
Very rare in children
Mirror movements – involuntary movements of one side of body that are mirror reversals of intended movements on the other side
Normal during infancy and disappear before age 10 – persistence can be familial trait
Obligatory movements are abnormal at any age

9. General Characteristics (3)
Myoclonus – involuntary movements characterized by rapid muscle jerks
Can be rhythmic, nonrhythmic; focal, multifocal or generalized; spontaneous, action or reflex
Stereotypies – repeated, purposeless movements
Can be simple or complex

10. General Characteristics (4)
Tics – “habit spasms”; complex, stereotyped movements or utterances that are sudden, brief and purposeless
As opposed to chorea, are stereotyped
Can be suppressed for short periods, with some discomfort and are never part of a voluntary movement

11. General Characteristics (5)
Tremor – involuntary oscillating movement with a fixed frequency
Product of frequency and amplitude are constant
Frequency decreases with age, amplitude increases
Shuddering, ataxia and dysmetria are not tremor because they lack rhythm

12. General Characteristics (6)
Fasciculations
Rippling movements of a small group of muscles, benign with low amplitude common in young
Myokymia
Slow, worm-like, undulating movements usually in the face but also in the large limb muscles
Seizures

13. Chorea - Differential Neurodegenerative diseases (Huntington’s)
Lesions of the basal ganglia
Drugs (Dopamine agonists, stimulants, opiates, antiepileptics, estrogens)
Metabolic conditions (Wilson’s, hyperthyroid, hyperglycemia, hypoglycemia, electrolyte disorders)
Systemic disorders (Syndenham’s, lupus, chorea gravidarum)
Essential chorea syndromes
Paroxysmal chorea
Cardiopulmonary bypass (1 to 10%)

14. Huntington’s - Genetics
Autosomal dominant, full penetrance, 50% chance to pass to
Offspring, CAG repeat of greater than 39 is diagnostic

15. Huntington’s - Features
Age of onset typically 35-45, but childhood to >80 has occurred
Chronic, progressive, generalized chorea
Failure of indirect pathway
Can have other movement disorders present (parkinsonism, dystonia and tic)
Dementia late in disease

16. Syndenham’s - Features
A.K.A. Rheumatic Chorea
10 to 30% of cases of rheumatic fever
Symptoms appear 1 to 6 months after infection and last 5 to 15 weeks
Recurs in 20% of patients
Can cause mental status changes
Most cases in ages 5 to 15
Migratory chorea of limbs and face
Cardinal features of chorea, hypotonia, dysarthria and emotional lability
Treatment with steroids and treatment for infection

17. Chorea Gravidarum
Due to antiphospholipid antibody syndrome, with or without SLE
Usually during 2nd to 5th month, sometimes postpartum
Cognitive changes may be present
Symptoms resolve spontaneously in weeks to months

18. Chorea – workup/treatment
Neuroimaging, glucose, electrolytes, thyroid studies, CBC with smear, copper studies, genetic studies
Treat underlying cause
Can use clonazepam as first line
Neuroleptics are second line
Follow-up important because chorea tends to evolve

19. Myoclonus - Evaluation
Distribution
Generalized, focal, multifocal, segmental
Temporal profile
Continuous, intermittent
Activation
Rest, voluntary, stimulus

20. Myoclonus - classification
First – determine major category
Second – match clinical and lab/radiology findings with diagnosis within major category

21. Myoclonus - Categories
Physiological
Essential
Epileptic
Symptomatic

22. Myoclonus - Physiologic
Neurologically normal persons
Sleep jerking – most common
Also be anxiety or exercise related
Diagnosis based on history alone
NO TREATMENT NEEDED

23. Myoclonus - Essential
Clinically significant jerking occuring at any time
Usually most prominent or only finding
Differs from physiologic because of social or physical disability
Condition progresses slowly or not at all
Hereditary (Autosomal dominant) or sporadic
Face, trunk and proximal muscles
Clinical features and family history make diagnosis
Clonazepam drug of choice is treatment needed

24. Myoclonus - Epileptic
In persons with chronic seizure disorder and epileptiform activity on EEG
Juvenile Myoclonic Epilepsy
Myoclonic seizures with generalized tonic-clonic or absence
Onset in adolescence with peak between 12 and 18
Abnormality on chromosome 6

25. Myoclonus - symptomatic
Neurodegenerative syndromes
Infection/Postinfection
Drugs, toxins, metabolic disorders
Hypoxia
Focal or segmental
Paraneoplastic
Post-CNS injury

26. Myoclonus – workup/treatment
Electrolytes, glucose, renal and hepatic function testing, drug and toxin screening, brain imaging, EEG
Genetic studies, tissue biopsy and CSF studies as clinically indicated
Treatment is clonazepam
Valproic acid for JME

27. Tics Can be suppressed for short periods of time Simple or complex
Transient tics occur in 20% of children under 10 years of age
Gilles de la Tourette syndrome

28. Tourette’s 10 cases per 10,000 population
Onset between 2 and 15 (mean 6.5)
Vocal tics begin 1 to 2 years after motor tics
75% are tic free by 18 years old
Increase in severity with stress, caffeine, stimulants, fatigue, heat, steroids
Decrease with THC, alcohol, nicotine and decrease in mental activity
Disability usually social but may be physical injury
50% also with ADHD, 30 to 50% with OCD
Multiple other behavioral problems

29. Tourette’s Diagnosis: Multiple motor and one or more vocal tics
Onset before age 18
Tics occur many times a day, nearly every day
Variation in location, frequency and complexity over time
Not related to toxins or CNS disease
Symptoms cause impairment

30. Tourette’s Genetic factors in 75% with bilineal transmission in 25%
Radiologic/Laboratory workup not needed
Treatment
Clonidine, benzodiazepines, haldol, risperdal, clozapine, reserpine
Surgery for drug-resistant tics, but not shown effective in Tourette’s

31. Tremor
All people have a physiologic tremor inherent in movement that cannot be normally noticed unless measured
Fine or coarse
Resting, postural, action

32. Connor GS et al. Esential Tremor: A Practical Guide to Evaluation,
Diagnosis, and Treatment. Clinician, 19(2): 2001.

33. Tremor - differential
Drug induced (Anticonvulsants, antidepressants, caffeine, steroids)
Hyperthyroidism
Juvenile Parkison’s disease (Not common)
Paroxysmal Dystonic Head Tremor
Essential tremor

34. Essential tremor 1 in 20 arise in childhood
70% of pediatric cases in males
Not associated with other neurologic disturbances
Genetics – ETM1 on 3q13, ETM2 on 2p25, complete penetrance, autosomal dominant
Most common movement disorder
Prevalence of 0.1 to 22% worldwide
20 times more common than Parkinson’s

35. ETM1 – Chromosome 3q13

36. ETM2 – Chromosome 2p25

37. Essential tremor - Features
4 to 8 hertz
Usually in limbs, occassionally head and face
Appears first in hands because it is enhanced by greater precision movements
Can be postural (early) and action (later)
Generally life-long
Can impact writing and other functions
Worsening due to enhanced physiologic tremor
Enhanced by anxiety, attempts to suppress, fatigue
Tremor can become severe with significant disability

38. Connor GS et al. Esential Tremor: A Practical Guide to Evaluation,
Diagnosis, and Treatment. Clinician, 19(2): 2001.

39. Essential Tremor – workup/treatment
Neuroimaging normal, pathology not indicated, genetic research possible if familial
Treatment usually not needed
If needed use beta-blockers first
Then anticonvulsants, benzos, calcium channel blockers, botox
If severe tremor, drug-resistant, deep brain stimulation

40. DBS - Thalamus

41. DBS - Localizing

42. DBS - Leads

43. References Postgraduate Medicine, 108(5), Oct 2000.
Pranzatelli MR. Movement Disorders in Childhood. Ped Rev, 17(11): 1996.
Gerald M. Fenichel. Clinical Pediatric Neurology, 4th Edition
All videos courtesy of Dr. Difazio