Dyskinesias in Children/Adolescents

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. 2001. • All videos courtesy of Dr. Difazio