Primary Image

RehabMeasures Instrument

International Cooperative Ataxia Rating Scale

Last Updated

Purpose

The ICARS was developed to quantify the level of impairment as a result of ataxia as related to hereditary ataxias. Disorders rated as subscales within the ICARS are: Postural and gait disturbances, Limb Ataxia, Dysarthria, and Oculomotor disorders.

Link to Instrument

Instrument Details

Acronym ICARS

Administration Mode

Paper & Pencil

Cost

Free

Key Descriptions

  • 19 items with 4 subscales:
    1) Posture and Gait Disturbance
    2) Kinetic Function
    3) Speech Disorder
    4) Oculomotor Disorders
  • Scoring:
    1) Minimum Score: 0
    2) Maximum score: 100
    3) Higher score indicates greater impairment
  • Each subscale has an ordinal scale with 0 indicating normal and the higher score indicating greatest impairment or that the patient is unable to complete the task.
  • Scale is typically administered by a physician. However, it can be administered by an appropriately trained individual such as a PT or OT.

Number of Items

19

Equipment Required

  • 1 pre-drawn pattern of Archimedes' Spiral

Time to Administer

20-30 minutes

Depends on proficiency of administrator and amount of involvement of patient

Required Training

No Training

Instrument Reviewers

Initially reviewed by Maryleen K. Jones, PT, MPT, NCS, CLT in 10/2013.

ICF Domain

Activity

Considerations

  • Item ratings on subscales are not “qualified ” with ratings being termed “slightly reduced”, “markedly reduced” and “extremely slow” - it would be helpful for consistency to know what qualifies as “slightly reduced gait speed”, etc.
  • Some items scores are related to others thus the scoring on the items may indirectly bias the score/rating of another items 
  • The ICARS may not be sensitive enough to detect change in a short assessment period 
  • Further Studies are needed to validate the use of the ICARS in other neurological populations that experience ataxia, such as Multiple Sclerosis, Stroke, Traumatic Brain Injury, Neoplastic Brain Injury, Spinal Cord Injury or Toxicity

Do you see an error or have a suggestion for this instrument summary? Please e-mail us!

Movement and Gait Disorders

back to Populations

Test/Retest Reliability

Spinocerebellar Ataxia:

(Schmitz-Hubsch et al, 2006)

  • Excellent test retest reliability (ICC = 0.97)

Interrater/Intrarater Reliability

Spinocerebellar Ataxia:

(Schmitz-Hubsch et al, 2006)

  • Excellent interrater reliability (ICC = 0.95) for full scale (n = 97)
  • Excellent interrater reliability for subscales:
    • Posture and Gait Disturbances (ICC = 0.96)
    • Kinetic Functions (ICC = 0.88)
    • Oculomotor Disorder (ICC = 0.87)
    • Speech Disorders (ICC = 0.76)
  • Excellent Intrarater reliability (ICC = 0.97) for full scale (n = 34) based on limited set of intrarater assessments
  • Excellent Intrarater reliability for subscales:
    • Posture and Gait Disturbances (ICC = 0.93)
    • Kinetic Functions (ICC = 0.95)
    • Speech Disorder (ICC = 0.85)
    • Oculomotor Disorders (ICC = 0.81)

 

Spinocerebellar Ataxia & Friedreich’s Ataxia:

(Storey et al, 2004; n = 22; n = 11 for SCA Type 1; n = 1 for SCA Type 2, and n = 10 for Friedreich’s Ataxia; Avg. Age of 37.6. SD not reported)

  • Excellent: Interrater reliability (Kendall’s w = 0.994 / 95% Confidence Interval (CI) = 0.988 - 0.997) for full scale (n = 22)
  • Excellent Interrater reliability for subscales:
    • Posture and Gait Disturbances = (Kendall’s w = 0.989/95% CI = 0.989 - 0.997)
    • Kinetic Function = (Kendall’s w = 0.981/95% CI =0.962 - 0.991)
    • Speech Disorder = (Kendall’s w = 0.791/95% CI = 0.598 - 0.899)
    • Oculomotor Disorder = (Kendall’s w = 0.990/ 95% CI = 0.990/95% CI = 0.987 - 0.998)

Internal Consistency

Friedreich’s Ataxia:

(Burk et al, 2009, n = 96, mean age 29 (13); Disease Duration = 16 (10) years.)

  • Poor Cronbach’s alpha = 0.69

 

Spinocerebellar Ataxia:

(Schmitz-Hubsch et al, 2006)

  • Adequate: Cronbach’s alpha 0.95 – Items 17 & 19 indicate redundancy (gaze nystagmus and saccade dysmetria)

 

Multiple System Atrophy Cerebellar Type:

(Tison et al, 2002, n = 50; mean age = 67.6 years, SD not reported, Disease Duration = 66 months SD not reported.)

  • Excellent (Cronbach’s alpha = 0.93)

 

Multiple System Atrophy Parkinson’s Type:

(Tison et al, 2002, = 50; mean age = 67 years, SD not reported, Disease Duration = 82.8 months, SD not reported)

  • Adequate Cronbach’s alpha = 0.79

Criterion Validity (Predictive/Concurrent)

Frediedreich’s Ataxia:

(Metz et al, 2012; n = 603; mean Age = 27 (13.2) years; Disease Duration = 14.3 (9.1) years)

  • Adequate predictive validity for disease progression of 2.5 points +/- 0.18 points for early onset patients (< 14 yrs of age for first 20 years of disease) and later onset (> 14 yrs of age) 1.8 points +/- 0.27 points

 

Spinocerebellar Ataxia:

(Schmitz-Hubsch et al, 2006)

  • Excellent correlation to Barthel Index (r = 0.70)
  • Adequate correlation to disease duration (r = 0.43)

Construct Validity

Spinocerebellar Ataxia:

(Schmitz-Hubsch et al, 2006)

ICARS score to disease Stage as rated by Klockgether & Colleagues:

  • Stage 0 = ICARS Score of 2.1 +/- 1.4
  • Stage 1 = ICARS Score of 28.8 +/- 11.7
  • Stage 2 = ICARS Score of 45.8 +/- 15.6
  • Stage 3 = ICARS Score of 66.0 +/- 99

Floor/Ceiling Effects

Friedreich’s Ataxia:

(Metz et al, 2012)

  • Adequate ICARS Total Score: Floor effect 1% and ceiling effects 2%
  • Adequate for Subscales:
    • Posture & Gait Subscales: 6% Ceiling Effect
    • Oculomotor Subscale: 10% Floor Effect

Responsiveness

Friedeich’s Ataxia:

(Fahey et al, 2007; n = 76; assessed at 12 months)

  • Adequate: Effect Size = 0.26 with 0.73 Standard Response Mean

 

Spinocerebellar Ataxia:

(Franca et al, 2009; n = 34; assessed at 13 months)

  • Adequate: Effect Size = 0.26

Non-Specific Patient Population

back to Populations

Construct Validity

Chronic Alcoholics:

(Fitzpatrick et al, 2012; n = 49, mean Age = 53.41 (9.53) years; Years of Heavy Drinking = 33.80 (10.64) years)

  • Excellent correlation coefficient (r = 0.60%)
  • Suggested score of 14 strongly suggests cerebellar dysfunction

Bibliography

Burk, K., Malzig, U., et al. (2009). "Comparison of three clinical rating scales in Friedreich ataxia (FRDA)." Mov Disord 24(12): 1779-1784. Find it on PubMed

Cano, S. J., Hobart, J. C., et al. (2005). "International Cooperative Ataxia Rating Scale (ICARS): appropriate for studies of Friedreich's ataxia?" Mov Disord 20(12): 1585-1591. Find it on PubMed

Fahey, M., Corben, L., et al. (2007). "How is disease progress in Friedreich’s ataxia best measured? A study of four rating scales." Journal of Neurology, Neurosurgery & Psychiatry 78(4): 411-413.

Fitzpatrick, L. E., Jackson, M., et al. (2012). "Characterization of cerebellar ataxia in chronic alcoholics using the International Cooperative Ataxia Rating Scale (ICARS)." Alcoholism: Clinical and Experimental Research 36(11): 1942-1951.

Metz, G., Coppard, N., et al. (2013). "Rating disease progression of Friedreich's ataxia by the International Cooperative Ataxia Rating Scale: analysis of a 603-patient database." Brain 136(Pt 1): 259-268. Find it on PubMed

Saute, J. A. M., Donis, K. C., et al. (2012). "Ataxia Rating Scales—Psychometric Profiles, Natural History and Their Application in Clinical Trials." The Cerebellum 11(2): 488-504. 

Schmitz-Hubsch, T., Tezenas du Montcel, S., et al. (2006). "Reliability and validity of the International Cooperative Ataxia Rating Scale: a study in 156 spinocerebellar ataxia patients." Mov Disord 21(5): 699-704. Find it on PubMed

Storey, E., Tuck, K., et al. (2004). "Inter-rater reliability of the International Cooperative Ataxia Rating Scale (ICARS)." Mov Disord 19(2): 190-192. Find it on PubMed

Tison, F., Yekhlef, F., et al. (2002). "Application of the International Cooperative Ataxia Scale rating in multiple system atrophy." Mov Disord 17(6): 1248-1254. Find it on PubMed

Trouillas, P., Takayanagi, T., et al. (1997). "International Cooperative Ataxia Rating Scale for pharmacological assessment of the cerebellar syndrome. The Ataxia Neuropharmacology Committee of the World Federation of Neurology." J Neurol Sci 145(2): 205-211. Find it on PubMed

Save now, read later.