Dsytonia virti shah

1. Chorea, athetosis and
dystonia
DR VIRTI SHAH

2. Basal Ganglia and pathways
 Structures included –
1. Caudate nucleus
2. Putamen
3. Globus pallidus – interna and externa (GPi and GPe)
4. Subthalamic nucleus
5. Substantia Nigra – pars compacta (SNc) and pars reticulata(SNr)
 Caudate and putamen – striatum
 Putamen and globus pallidum – lentiform nucleus
 Striatum is main region for receiving information from cortex and SN

4. Direct pathway
 Direct pathway helps in
initiating and
maintaining movements
 Substantia nigra
stimulates the direct
pathway

5.  Indirect pathway plays a
role in suppression of
unwanted actions.
 Substantia Nigra inhibits
this indirect pathway
 In normal states direct and
indirect pathways act
together for causing
smooth movements and
avoiding involuntary
actions.

6. Dystonia
 Sustained muscle contractions causing twisting and repetitive movements or
abnormal postures.
 Due to co-contraction of agonists and antagonist muscles
 4 consistent features of all dystonia –
1. Relatively long contractions (compared to myoclonus and chorea)
2. Simultaneous contraction of agonist and antagonist
3. Twisting of affected body parts(except in facial muscles – patterned movement)
4. Continual contraction of same muscle groups

7. Classification
 By age of onset
1. Early onset ≤ 26 years
2. Late onset > 26 years
 Useful for prognosis
 Younger the age of onset more likely the dystonia will become severe and spread
to multiple body parts
 Older age – more likely to remain focal

8.  By distribution –
1. Focal – single area of body affected – e.g. blepharospasm, writers cramp, torticollis
2. Segmental – 2 or more contiguous parts affected – e.g meigs syndrome –
oromandibular and blepharospasm
3. Generalised - combination of crural (both legs or leg plus trunk) and involvement
of any other body parts
4. Hemidystonia - one half of body affected – this is usually secondary due to
stroke, perinatal injury, trauma
5. Multifocal – dystonia which doesnot fit into the above category.

9. Blepharospasm
 Older individuals affected
 Women> men
 Begins as excessive blinking followed by longer closing of eyes
 Muscle involved is orbicularis oculi – 7th nerve
 Symmetrical in both eyes
 Sensory trick – touching corner of eye, talking
 Bright light aggravates
 Spread of blepharospasm is more common than other focal dystonia

10. Cervical dystonia
 Age – 20-50years
 Head can either turn to one side( rotational torticollis), bend forward (antecollis)
or backwards (retrocollis) or a combination
 Muscles involved are supplied by 11th cranial nerve and upper cervical roots
 Sensory trick – touching the face or back of head
 Pain in neck muscle is common

12. Oromandibular dystonia
 Muscles involved are supplied by 5th cranial nerve
 Usually associated with lingual dystonia (CN 12)
 Jaw opening dystonia – jaw is pulled down by pterygoids
 Jaw clenching dystonia – jaw shut by masseter and temporalis
 Can cause difficulty in chewing and swallowing
 Sensory trick – placing of object or biting down on an object like a pencil

13. Task specific dystonia
 Writers cramp – only action of writing will bring out tightening of fingers, forearm
and arm muscles
 In 15% - spreads to other arm
 Sensory tricks – placing pen inbetween other fingers, placing non-writing hand on
top of writing hand
 Musicians cramp – involves fingers in instrumentalists like pianists, guitarists.

15. Generalised dystonia

17.  By etiology
1. Primary
2. Dystonia plus
3. Secondary dystonia
4. Heredodegenerative dystonia

18. Primary dystonia
 Only dystonia with/without tremor
 No other neurological abnormality
 Eg – DYT 1,2,4,6,7
Dystonia Plus
 Associated with parkinsonism or
myoclonus without degeneration or loss
of neurons.
 Eg – DYT 3,5,8,9,10

20. Secondary Dystonia
1. Perinatal injury
2. Encephalitis
3. Hypoxic brain damage
4. Autoimmune – APLA syndrome, Sjogrens
5. Metabolic – hypoparathyroidism
6. Drug induced – levodopa, D2 blocking drugs like metoclopramide
7. Toxin – CO, cyanide

21. Heredodegenerative
 As a part of a disease involving other neurological structures other than dystonia.
 Wilsons disease
 NBIA
 Niemann – Pick C
 Associated with PSP, MSA

22. Treatment
 Non pharmacological
 Physiotherapy –
 Helps in preventing muscle shortening
 Increases range of motion and flexibility
 Gait and balance training
 Examples include – Kinesiotherapy for cervical stretching, active and passive neck
movements, functional electrical stimulation of non dystonic muscles with
opposite action for cervical dystonia

23.  Pharmacological –
1. Dopaminergic drugs – helps in DRD
2. Antidopaminergic therapy – tetrabenazine
3. Anticholinergic – trihexyphenidyl
4. Muscle relaxants like baclofen
5. Benzodiazepine
6. Botulinum toxin
 Surgical -
 Deep Brain stimulation of Globus
Pallidus internus may help in certain
dystonia

25. Chorea and Athetosis

26. Definitions
 Chorea – involuntary, irregular, purposeless, non rhythmic, abrupt, unsustained
movements that appear to flow from 1 body part to another.
 2 additional features
1. patients with chorea often blend or incorporate the chorea into their normal
movements, as if they are attempting to hide it. This phenomenon is called
parakinesia. For example, when chorea is present in the arm, a patient may try to
blend chorea by lifting or moving the arm to a target in the same direction as the
choreic movements.
2. Motor impersistence – inability to maintain a sustained contraction – milkmaid
grip, inability to keep tongue protruded

27.  Athetosis - slow, writhing, continuous, involuntary movements. Usually present in
distal limbs.
 Ballismus – involuntary, large amplitude, flinging and flailing limb movements of
proximal limbs

28. Approach to chorea – based on body part involved

29. Can be acquired or sporadic
Acquired causes
Structural Strokes, tumors, demyelination
Metabolic Non-ketotic hyperglycemia
Hypoglycemia
Hypo/hypernatremia
Liver/kidney disease
Hypo/hyperparathyroidism
Infectious Toxoplasma, HIV, Prion disease
Autoimmune Sydenhams chorea
SLE,APLA, SS
Paraneoplastic
Drugs Levodopa
Cocaine, amphetamine
Neuroleptic
Others Chorea gravidarum, OC pill use
Polycythemia vera

30. Genetic causes
 HUNTINGTONS DISEASE
 Clinical features-
 Chorea – most common feature – present in forehead with elevation of eyebrows
followed by generalised chorea
 Gait difficulty – dance like gait
 Bradykinesia and parkinsonism
 Dystonia, tics, myoclonus – later stages
 Apart from movement disorder , it has behavioural changes like depression, apathy,
agitation
 Dementia
 Autosomal dominant
 CAG repeats ≥ 36

31.  Other genetic causes of chorea –
1. Huntington like disorders 1-4
2. Chorea acanthocytosis
3. Benign hereditary chorea
4. SCA 2, 17
5. Neurodegeneration with Brain Iron accumulation
6. Mc Leods disease

32. Principles of Chorea Treatment
 Step 1: Does chorea need to be treated? When it is mild and nonbothersome, treatment is not
required.
 Step 2: Is specific treatment available?
 Step 3: If chorea is not controlled by specific treatment or specific treatment is not available,
what symptomatic therapies should be selected?
 Step 4: Are there any other symptoms than chorea that require treatment or surveillance?
Patients can benefit from multidisciplinary approach.
 Step 5: Does any family member need further evaluation or genetic counseling?

36. Thank you