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RehabMeasures Instrument

Canadian Neurological Scale

Purpose

The CNS provides a standardized neurological assessment of cognitive and motor function in stroke patients (alert or drowsy).

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Instrument Details

Acronym CNS

Area of Assessment

Aphasia
Cognition
Functional Mobility

Assessment Type

Observer

Administration Mode

Paper & Pencil

Cost

Free

Diagnosis/Conditions

  • Stroke Recovery

Populations

Key Descriptions

  • The CNS assesses alertness in stroke patients.
  • Includes the following assessments:
    1) Level of consciousness
    2) Orientation
    3) Aphasia
    4) Motor strength
  • Assessments of motor function are separated into two sections:
    1) A1 - administered if patient is able to understand and follow instructions
    2) A2 - administered in the presence of comprehension deficits
  • Each motor item is rated for severity and each rating is weighted “according to the relative importance of a particular neurologic deficit” (Cote et al., 1989).
  • Scores submitted form each domain section are summed to provide a total score out of a possible 11.5.
  • Lower scores are representative of increasing severity.
  • CNS scores can be converted into NIHSS Scores using: NIHSS = 23 – (2 X CNS Score).

Time to Administer

10 minutes

Required Training

No Training

Age Ranges

Adult

18 - 64

years

ICF Domain

Body Function
Activity

Measurement Domain

Cognition
Motor

Considerations

Assessment using the CNS is focused on limb weakness over other possible neurological impairments (Cuspineda et al, 2003; Muir et al, 1996).

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Stroke

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Normative Data

Acute Stroke: (Nilanont et al. 2010; n = 350; mean age = 63.4 (range 19 to 93) years; Thai sample)

Scale

Score Median (range)

CNS score

9 (1.5–11.5)

NIHSS score

 4 (0–26)

CNS scores can be reliably converted into NIHSS Scores using the following conversion:

NIHSS = 23 –  (2 X CNS Score)

Interrater/Intrarater Reliability

Acute Stroke: (Bushnell at al. 2001; n = 59 retrospective study; Cote et al. 1989; n = 157; mean age = 68.8 years)

  • Excellent interrater reliability (ICC = 0.97; raters = 2 neurologists)
  • Excellent intra-rater reliability (r = 0.924; correlation of nurse and physician ratings)

Review of common stroke measures: (D'Olhaberriague et al, 1996)

  • Excellent Interrater Agreement; Kappa = 0.76

Internal Consistency

Acute Stroke: (Cote et al, 1986; n = 34; mean age = 61.2 years & Cote et al, 1989)

  • Excellent internal consistency (Cronbach's alpha = 0.89)
  • Excellent internal consistency (Cronbach's alpha = 0.79)

Criterion Validity (Predictive/Concurrent)

Acute Stroke: (Cote et al, 1989)

  • Excellent concurrent validity with Neurologic Examination (r = 0.775; mean of 3.71 hours between assessments)

Item

Number

Spearman r 95% CI

Level of consciousness

155

0.574*

0.384 - 0.764

Orientation

149

O.71S*

0.583 - 0.849

Speech

153

0.S91*

0.581 - 0.801

Weakneas

134

0.767*

0.695 - 0.839

Global score versus total score

155

0.776*

0.720 - 0.830

*p < .001

Excellent to moderate predictive validity with:

  • Death within 6 months (crude odds ratio = 0.73)
  • Cardio/CVA event within 6 months (crude odds ratio = 0.70)
  • Independence with ADLs within 6 months (crude odds ratio = 1.60)
  • Overall, low initial scores correlated with higher mortality, greater incidence of recurrent vascular events, and lower independence at 6 months post-stroke

Acute Stroke: (Muir et al, 1996; n = 344, median age = 69 years; CNS and other common measures used in stroke)

 

MCANS

NIHSS

Guy's

CNS

.977**

-.948**

.397*

** Excellent; * Adequate

MCANS = Middle Cerebral Artery Neurological Score

NIHSS = National Institutes of Health Stroke Scale 

Guy's = Guy's prognostic score (from clinical data)

Construct Validity

Acute Stroke: (Cote et al, 1989)

  • Excellent correlation between the CNS and a standard neurologic examination (r = 0.769)

Content Validity

The scales content scale was validated by a panel of experts who agreed on the items to be included and their respective weights No statistical analysis provided (Cote et al, 1989).

Responsiveness

Acute Stroke: (Hagen et al, 2003; n = 136; mean age 70 (11) years; sensitivity compared across 3 measures)

Outcome measure (months)

Mean difference

SD

Min

Max P-value~

SRM

Barthel Index (1–3)

1.1982

2.3696

-3

9

<0.001***

0.5057

CNS (1–3)

0.2072

0.7245

-1.5

2

0.004**

0.286

MMSE (1–3)

1.036

2.6317

-8

8

<0.001***

0.3937

Barthel Index (3–6)

0.1532

1.8887

-8

5

0.263

0.0811

CNS (3–6)

0.7115

0.7115

-2

3.5

 0.003**

0.2849

MMSE (3–6)

0.5586

2.2225

-5

8

0.011*

0.2513

CNS = Canadian Neurological Scale 

MMSE = Mini-Mental State Examination

~Wilcoxon signed rank test; *P < 0.05; **P < 0.01; ***P < 0.001

Bibliography

Bushnell, C., Johnston, D., et al. (2001). "Retrospective assessment of initial stroke severity: comparison of the NIH Stroke Scale and the Canadian Neurological Scale." Stroke 32(3): 656. Find it on PubMed

Cote, R., Battista, R., et al. (1989). "The Canadian Neurological Scale: validation and reliability assessment." Neurology 39(5): 638. Find it on PubMed

Cote, R., Hachinski, V., et al. (1986). "The Canadian Neurological Scale: a preliminary study in acute stroke." Stroke 17(4): 731. Find it on PubMed

Cuspineda, E., Machado, C., et al. (2003). "Predicting outcome in acute stroke: a comparison between QEEG and the Canadian Neurological Scale." Clinical EEG electroencephalography 34(1): 1-4. Find it on PubMed

D'Olhaberriague, L., Litvan, I., et al. (1996). "A reappraisal of reliability and validity studies in stroke." Stroke 27(12): 2331. Find it on PubMed

Hagen, S., Bugge, C., et al. (2003). "Psychometric properties of the SF-36 in the early post-stroke phase." J Adv Nurs 44: 461-468. Find it on PubMed

Muir, K., Weir, C., et al. (1996). "Comparison of neurological scales and scoring systems for acute stroke prognosis." Stroke 27(10): 1817. Find it on PubMed

Nilanont, Y., Komoltri, C., et al. (2010). "The Canadian Neurological Scale and the NIHSS: development and validation of a simple conversion model." Cerebrovasc Dis 30(2): 120-126. Find it on PubMed

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