Dystonia

Question 1

What is the most common movement disorder

Answer 1

essential tremor

Question 2

What is the second most common movement distorder

Answer 2

parkinson’s

Question 3

What is the 3rd most common movement disorder

Answer 3

Dystonia

Question 4

Dystonia: definition

Answer 4

sustained muscle contractions causing repetitive twisting movements or abnormal postures during functional movements
*misrepresentation of the body in the brain

Question 5

3 axes of classification

Answer 5

1. etiology/cause (primary, heterotodegenerative, secondary)
2. Age of onset (early, late)
3. Distribution (focal, segmental, multifocal, generalized, hemi-dystonia)

Question 6

3 types of primary dystonias

Answer 6

1. Primary “pure”
2. Primary plus
3. Primary Paroxysmal

Question 7

Primary Pure dystonia

Answer 7

Torsion dystonia is the only clinical sign

No identifiable exogenous cause or other inherited or degenerative disease

Question 8

Primary plus dystonia

Answer 8

Torsion dystonia is a prominent sign, but is associated with another movement disorder (myoclonus, parkinsonism)
No evidence of neurodegeneration

Question 9

Primary Paroxysmal Dystonia

Answer 9

torsion dystonia occurs in brief episodes with normalcy in between
idiopathic

Question 10

3 forms of primary paroxysmal dystonia

Answer 10

1. Paroxysmal kinesigenic dyskinesia (PKD)- attacks induced by sudden movement
2. paroxysmal exercise-induced dystonia (PED)- attacks induced by exercise
3. Non-kinesigenic form (PNKD)- attacks induced by alcohol, coffee, tea, etc

Question 11

Heredodegenerative Dystonias

Answer 11

dystonia is a feature (amongst other neurodegenerative signs)
example = wilson’s disease
Both hereditary and degenerative

Question 12

Secondary Dystonias

Answer 12

Dystonia is a symptom of identified neurological condition (brain tumor, focal brain lesion, exposure to drugs and chemicals)

Question 13

Early-Onset dystonia

Answer 13

onset at 20-30yrs (before 30)

starts in single leg or arm, progresses to involve other limbs and the trunk

Question 14

Late onset dystonia

Answer 14

starts in the neck, cranial muscles, or one arm

remains localized with restricted progression to adjacent muscles

Question 15

Focal dystonia

Answer 15

single body segment (writers cramp)

Question 16

Segmental dystonia

Answer 16

Contiguous body regions (cranial and cervical, cervical and upper limb- Cervical dystonia is common)

Question 17

Multifocal dystonia

Answer 17

non-contiguous body regions (upper limb and lower limb, cranial and upper limb)

Question 18

Generalized dystonia

Answer 18

both legs and at least one other body region (usually one or both arms)

Question 19

Hemidystonia

Answer 19

half of the body (usually secondary to a structural lesion in the CL basal ganglia)
Cerebellum –> control of IL side affected
Basal Ganglia –> Control of CL side affected

Question 20

Risk factors of dystonia

Answer 20

1. repetition/excessive practice
2. Poor ergonomics
3. stress
4. trauma/anatomic defects
5. compulsive personality, perfectionists, impatient
6. environment
7. aberrant physiology
8. genetics (susceptibility gene)

Question 21

physiological circuits involved in dystonia

Answer 21

1. Basal ganglia
2. cerebellar
3. SMA (primary motor cortex)
4. Sensory motor cortex

Question 22

Pathogenesis of excessive practice and dystonia

Answer 22

excessive practice –> degradation of cortical and subcortical representation –> loss of sensitivity in distinguishing between sensory stimuli
*loss of sensitivity: excessive/persistent firing of neurons in both sensory and motor cortex independent of the stimuli

Question 23

Can excessive practice lead to dystonia on its own?

Answer 23

No! must be in combination with genetic mutations, environmental causes, and susceptibility genes

Question 24

Graphesthesia

Answer 24

ability to identify objects drawn on your hand with another finger without visual cues

Question 25

Stereognosis

Answer 25

being able to identify objects by using only tactile perceptors and fingers (no visual cues)

Question 26

Components of the neuro exam for dystonia

Answer 26

1. motor exam
2. sensory exam (graphesthesia, stereognosis)
3. evaluation of task performance

Question 27

Fahn-Marsden Movement Scale

Answer 27

one of the most common scales used to evaluate presence of dystonia
looks at provoking and severity factors to grade dystonia

Question 28

Fahn-Marsden Movement Scale: Provoking Factors

Answer 28

0 = none
1 = only with particular action (writer's dystonia)
2 = with many actions
3 = on action of distant part of body or intermittently at rest
4 = at rest

Question 29

Fahn-Marsden Movement Scale: Severity Factor

Answer 29

0 = none present
1 = slight dystonia, clinical insignificance
2 = mild, obvious dystonia, but not disabling
3 = moderate, able to grasp with some manual function
4 = most severe, no functional grasp

Question 30

Factors of successful intervention in dystonia

Answer 30

1. time commitment (~30-60mins, must stop the abnormal movement)
2. Expectation: the pt must expect to get better and recognize it may take up to a year
3. supervision: for watching ergonomics and techniques

Question 31

Practice principles of dystonia

Answer 31

1. activities must be learned based, requiring focused attention
2. Address reacquisition of normal movement, then maitenance of the normal movement (break the task into subtasks)
3. Begin practice with a similar task, but only include the normal movements
4. May begin with mental rehearsal (firing 30% of the neurons)
5. start practice in an unusual nontarget position (but ultimately in the normal position)
6. consider compensatory strategy
7. short practice intervals, spaced over time
8. globally repetitive, but progressed with small increments
9. include sensory modificiation strategies
10. mirror imagery

Question 32

Sensory Modification Techniques

Answer 32

1. enhancement of sensory inputs- splint/tape, modifying interface
2. reinforce task performance with other senses (watching video tape, listening to the instrument)