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Purpose

The AST is a 12-item bedside screen to assess the presence and severity of apraxia. The screen is extracted from the comprehensive test of upper limb apraxia (TULIA).

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Instrument Details

Acronym AST

Cost

Free

Diagnosis/Conditions

  • Multiple Sclerosis
  • Parkinson's Disease & Movement Disorders
  • Stroke Recovery

Key Descriptions

  • 12 total gestures, including 1 meaningless imitation, 3 intra-transitive (communicative), and 8 transitive (tool-related).
  • Minimum score= 0 Maximum score= 12; Maximum score indicates no apraxia.
  • For each item, the participants receives a score of 1 (=pass) or 0 (=fail). Cut-off scores of 9 and 5 estimate abnormal/mild and severe apraxia, respectively.
  • The participant is seated in front of the examiner with both forearms placed on a table. Patients with hemiparesis execute gestures with their non-affected limb. Otherwise both upper limbs are tested.

Number of Items

12

Equipment Required

  • Seat Surface (for participant)
  • Table-Top Surface

Time to Administer

3 minutes

Required Training

No Training

Instrument Reviewers

Initially reviewed by Lauren Wiseman MS, OTRL on 9/29/14.

ICF Domain

Activity

Considerations

Multiple Sclerosis:

  • Limb apraxia may be associated with higher Expanded Disability Scale Status scores.
  • A higher prevalence of limb apraxia may be present in those with primary progressive and secondary progressive multiple sclerosis as compared to relapsing remitting multiple sclerosis.
  • Ataxia was not associated with apraxia in the multiple sclerosis population study. (Kamm et al, 2012)

Parkinson’s disease:

  • The scoring method of the AST neglects minor apraxic temporal-spatial errors that could be confounded by PD motor symptoms.
  • Ideomotor apraxia delineates PD from subtypes of atypical parkinsonism (corticobasal syndrome).
  • During advanced stages of PD, other motor and cognitive deficits (tremor, dysexecutive function) may confound errors not explained by apraxia alone. (Vanbellingen et al, 2011)

Stroke:

  • The AST is a convenient bedside screen for assessing apraxia
  • In the stroke population, the AST provides a 100% positive predictive value
  • In the stroke population, the AST provides 92% negative predictive value which may miss mild forms of apraxia
  • Aphasia with severe comprehension impairments may fall below cut-off scores in the AST due to impaired auditory comprehension during the pantomime items. (Vanbellingen et al, 2011)

Multiple Sclerosis

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Cut-Off Scores

Multiple Sclerosis: (Kamm et al, 2012; n = 76; mean age 44.8 (12.5); disease duration = 11.2 (9.6) years; average clinically isolated syndrome = 2 (2.6); average relapsing remitting type = 45 (59.2); average secondary progressive type = 23 (30.2); average primary progressive type = 6 (7.8); average Expanded Disability Status Scale = 3.4 (1.8)

  • Score of 10-12 indicates no praxis errors
  • Score of 6-9 indicates abnormal praxis or mild apraxia
  • Score of 5 or less indicates severe apraxia
  • Alternative cut-off score <5 for imitation part only, in case of severe language comprehension problems (can be presumed, if three or more amorphous movements occur for pantomime)

Construct Validity

Multiple Sclerosis

  • Excellent construct validity for correlation with Expanded Disability Status Scale (EDSS) scores (r = -.63) and Scale for the Assessment and Rating of Ataxia scores (r = -.60) (Kamm et al, 2012)

Content Validity

The Apraxia Screen of Tulia (AST) was created by reducing the Test for Upper Limb Apraxia (TULIA) down to 12 items by two clinical experts.

Parkinson's Disease

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Cut-Off Scores

Parkinson's Disease:(Vanbellingen et al, 2011; n = 75; mean age 63.4 (10.72); disease duration = 9.41 (5.79) years; mean Levadopa equivalent 806.87 (314.12) mg/day; Hoehn & Yahr stage 1 = 11, stage 2 = 31, stage 3 = 25, stage 4 = 8)

  • Score of 10-12 indicates no praxis errors
  • Score of 6-9 indicates abnormal praxis or mild apraxia
  • Score of 5 or less indicates severe apraxia
  • Alternative cut-off score <5 for imitation part only, in case of severe language comprehension problems (can be presumed, if three or more amorphous movements occur for pantomime)

Construct Validity

Parkinson’s disease

  • Adequate construct validity of the AST for correlation with Hoehn & Yahr stage (r = -0.32) (Vanbellingen et al, 2011)
  • Poor discriminant validity comparing the AST to the Movement Disorders Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS part III (r= 0.17, p= 0.1) (Vanbellingen et al, 2011)
  • Poor convergent validity between the AST and MDS-UPDRS part II (r= -0.35, p= 0.004) and Hoehn and Yahr (r= -0.32, p= 0.006) (Vanbellingen et al, 2011)

Content Validity

The Apraxia Screen of Tulia (AST) was created by reducing the Test for Upper Limb Apraxia (TULIA) down to 12 items by two clinical experts.

Stroke

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Standard Error of Measurement (SEM)

Stroke: (Vanbellingen et al, 2011; = 31; mean age = 63.4 (13.7); mean time post-acute CVA = 19.0 (5.3); mean time post chronic stroke = 57.3 (25.5)) (calculated from statistics in Vanbellingen et al, 2011)

  • SEM for AST apraxic = .648 *points (0-12 point scale)
  • SEM for AST non-apraxic = .22 * points (0-12 point scale) 
    * compared to same 12 items in original full-version of TULIA

Minimal Detectable Change (MDC)

Stroke: (calculated from statistics in Vanbellingen et al, 2011)

  • MDC for AST = 1.79 points (0-12 point scale)

Cut-Off Scores

Stroke: (Vanbellingen et al, 2011)

  • Score of 10-12 indicates no praxis errors
  • Score of 6-9 indicates abnormal praxis or mild apraxia
  • Score of 5 or less indicates severe apraxia
  • Alternative cut-off score <5 for imitation part only, in case of severe language comprehension problems (can be presumed, if three or more amorphous movements occur for pantomime)

Internal Consistency

Stroke: (Vanbellingen et al, 2011)

  • Excellent internal consistency (Cronbach alpha =0.92)

Construct Validity

Stroke (Vanbellingen et al, 2011)

  • Adequate construct validity for correlation with the screening version of the Token Test score (r = .81)
  • Poor construct validity for correlation with the Bell Test (p =>0.05)
  • Apraxia Screen of Tulia (AST) was constructed using the Test for Upper Limb Apraxia (TULIA)
  • Using item-reduction analysis based on classical test theory, two clinical experts reviewed 48 items from the TULIA to reduce the screen to 12 items (to make the AST). TULIA items with less inter-rater reliability, floor and ceiling effects, less internal consistency and lower content validity were excluded.
  • The six-point scoring system used in the TULIA was simplified to a dichotomous pass/fail scoring system.
  • Excellent test-retest reliability (ICC = .95)* results of the AST were compared to the TULIA to assess test-retest (Vanbellingen et al, 2011)

Content Validity

The Apraxia Screen of Tulia (AST) was created by reducing the Test for Upper Limb Apraxia (TULIA) down to 12 items by two clinical experts.

Bibliography

Kamm, C., Heldner, M., Vanbellingen, T., Mattle, H., Müri, R., & Bohlhalter, S. (2012). Limb apraxia in multiple sclerosis: prevalence and impact on manual dexterity and activities of daily living. Archives Of Physical Medicine And Rehabilitation, 93(6), 1081-1085. https://doi.org/10.1016/j.apmr.2012.01.008. Find it on Research Gate.

Ozkan, S., Adapinar, D., Elmaci, N., & Arslantas, D. (2013). Apraxia for differentiating Alzheimer's disease from subcortical vascular dementia and mild cognitive impairment. Neuropsychiatric Disease And Treatment, 9947-951. https://doi.org/10.2147/NDT.S47879. Find it on PubMed.

Vanbellingen, T., Kersten, B., Van de Winckel, A., Bellion, M., Baronti, F., Müri, R., & Bohlhalter, S. (2011). A new bedside test of gestures in stroke: the apraxia screen of TULIA (AST). Journal Of Neurology, Neurosurgery, And Psychiatry, 82(4), 389-392. https://doi.org/10.1136/jnnp.2010.213371. Find it on Research Gate.

Vanbellingen, T., Lungu, C., Lopez, G., Baronti, F., Müri, R., Hallett, M., & Bohlhalter, S. (2012). Short and valid assessment of apraxia in Parkinson's disease. Parkinsonism & Related Disorders, 18 (4), 348-350. https://doi.org/10.1016/j.parkreldis.2011.11.023. Find it on Research Gate.