Arm Dystonia Disability Scale

Original Editor - Harshit Anand Top Contributors - Harshit Anand and Kim Jackson

Objective[edit | edit source]

Fahn[1] created the Arm Dystonia Disability Scale (ADDS) to be more sensitive to focal dystonia of the arm. It extends the Fugl-Meyer Assessment (FMA) scale with ordinal grading of motor function difficulties in performing seven specific tasks using the arm, one of which is playing a musical instrument.

See the original Fugl-Meyer Assessment of Motor Recovery after Stroke

Intended Population[edit | edit source]

People with a genetic predisposition who experience repetitive stress in the form of frequent complex motor tasks and people diagnosed with arm dystonia. See the Dystonia and Dystonia Rating Scale pages for more info.

Method of Use[edit | edit source]

The Arm Dystonia Impairment Scale (ADDS) is intended to assess disability on a scale of 0 to 100%, with 100% representing no disability. It is computed as follows:

If functional activities are restricted, the next section is completed. Score the difficulty of executing each action in the list below as follows:

0 - None (or not applicable, i.e. patient does not perform the activity)

1 - Mild

2 - Moderate

3 - Marked

Activities[edit | edit source]

The subject is made to perform the following tasks and is scored on a scale of 0-3 as listed above.

  • Writing
  • Playing a musical instrument
  • Buttoning
  • Handling utensils and feeding
  • Hygiene (e.g. shaving, brushing teeth)
  • Grasping objects
  • Housework or outside job

Result[edit | edit source]

The final score is reduced by this amount proportional to the maximum possible, i.e.:

Final score = N % - [N% x (total score / 21)]

Variations[edit | edit source]

Variations in text[edit | edit source]

For three of the seven activities, Walter et al[4]. utilise somewhat different wordings:

"eating" (instead of "handling utensils and feeding") "shaving/teeth brushing" (rather than "hygiene (for example, shaving, cleaning teeth)" ”gardening” (instead of "housework or outside job")

Variation in Score Conventions[edit | edit source]

In some uses of the ADDS[5][6][7][8][9][10][4], the scores are given not in the canonical 0-100% ability range, but in a 0-3 range.

A graph depicting the other scales used in place of the Arm Dystonia Disability Scale (ADDS) by Fahn in the first phase of treatment (CTL in light blue, SMR in dark blue). (SMR, sensorimotor retraining, CTL, control).

Variation in Scale Nomenclature[edit | edit source]

In some studies that appear to use the ADDS, the scale is not referred to as such, but rather as one of the following:

  • "Fahn Arm Dystonia Scale" is referred to as Stinear 2004 EBR[11]
  • "Fahn dystonia disability scale" is referred to as Garraux 2004 Ann Neurol[12]
  • "Fahn dystonia scale" is referred to as Zeuner 2005 Mov Dis[13]
  • "severity from Fahn" is referred to as Lim 2003 Mov Dis[14]
  • “severity scale” is referred to as Wu 2010 JNNP[15]
  • “Global Disability Score” is referred to as Schmidt 2006 Neurol[9]

References[edit | edit source]

  1. Fahn S. Assessment of the primary dystonias. In: Munsat TL, ed. Quantification of neurologic deficit: Butterworths, 1989: 241-270
  2. Medical Centric. Dystonia, Causes, Signs and Symptoms, Diagnosis and Treatment. Available from: [Last accessed 23 April 2022]
  3. Tom Seaman. What is Dystonia and What Does it Feel Like? Available from: [Last accessed 23 April 2022]
  4. 4.0 4.1 Walter U, Buttkus F, Benecke R, Grossmann A, Dressler D, Altenmüller E. Sonographic alteration of lenticular nucleus in focal task-specific dystonia of musicians. Neurodegenerative diseases 2012;9:99-103.
  5. Lie-Nemeth TJ. Focal dystonia in musicians. Phys Med Rehabil Clin N Am 2006;17:781-787
  6. Jabusch HC, Vauth H, Altenmüller E. Quantification of focal dystonia in pianists using scale analysis. Mov Disord 2004;19:171-180.
  7. Sakai N. Slow down exercise for the treatment of focal hand dystonia in pianists. Med Probl Perform Artist 2006;21:25-28.
  8. Buttkus F, Weidenmüller M, Schneider S, et al. Failure of cathodal direct current stimulation to improve fine motor control in musician's dystonia. Mov Disord 2010;25:389-393.
  9. 9.0 9.1 Schmidt A, Jabusch HC, Altenmüller E, et al. Dominantly transmitted focal dystonia in families of patients with musician's cramp. Neurology 2006;67:691-693.
  10. Berque P, Gray H, Harkness C, McFadyen A. A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians. Med Probl Perform Artist 2010;25:149-161
  11. Stinear CM, Byblow WD. Impaired inhibition of a pre-planned response in focal hand dystonia. Exp Brain Res 2004;158:207-212.
  12. Garraux G, Bauer A, Hanakawa T, Wu T, Kansaku K, Hallett M. Changes in brain anatomy in focal hand dystonia. Ann Neurol 2004;55:736-739.
  13. Zeuner KE, Shill HA, Sohn YH, et al. Motor training as treatment in focal hand dystonia. Mov Disord 2005;20:335-341.
  14. Lim VK, Bradshaw JL, Nicholls MER, Altenmüller E. Perceptual differences in sequential stimuli across patients with musician's and writer's cramp. Mov Disord 2003;18:1286-1293.
  15. Wu CC, Fairhall SL, McNair NA, et al. Impaired sensorimotor integration in focal hand dystonia patients in the absence of symptoms. J Neurol Neurosurg Psychiatry 2010;81:659-665