Canadian Neurological Scale (CNS)

Purpose

The Canadian Neurological Scale (CNS) was developed as a simple tool to be used in the evaluation and monitoring“The process of checking the task over time for ‘quality control’ and the adjustment of behavior” (Stuss, 2009, p. 9-10)
of neurological status of patients with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More in the acute phase (Cote, Hachinski, Shurvell, Norris & Wolfson, 1986).

In-Depth Review

Purpose of the measure

The Canadian Neurological Scale (CNS) was developed as a simple tool to be used in the evaluation and monitoring"The process of checking the task over time for ‘quality control’ and the adjustment of behavior" (Stuss, 2009, p. 9-10)
of neurological status of patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More in the acute phase (Cote, Hachinski, Shurvell, Norris & Wolfson, 1986). The CNS evaluates 10 clinical domains, including mentation (level of conciousness, orientation and speech) and motor function (face, arm and leg).

Features of the measure

Items :

The CNS is comprised of 8-items measuring the level of consciousness, orientation, speech, motor function and facial weakness.

• If patient is alert or drowsy: monitor with CNS (sections A1 and A2)
• If patient is stuporous or comatose: monitor with Glasgow Coma Scale

MENTATION

Level of Consciousness

• Alert 3.0
  Spontaneous eye opening, normal level of consciousness
• Drowsy 1.5When stimulated verbally patient remains awake and alert but tends to doze

Orientation

• Oriented 1.0
  1. Where are you? (City and Hospital)
  2. What is the month and year?

  Speech can be slurred but must be intelligible.

• Disoriented 0.0Patient cannot state both place and time or cannot express answers in words or intelligible speech.

It is acceptable for patient to write answer to questions of orientation

Speech

• Receptive deficit 0.0Ask pt. 1) to close eyes; 2) Point to ceiling; 3) Does a stone sink in water?If pt. does not complete the above 3, go to Section A2.
• Expressive deficit 0.5
• Normal Speech 1.0

Adapated from Canadian Neurological Scale Cheat Sheet by Brown, M.and Li, J available from: http://www.heartandstroke.on.ca/site/c.pvI3IeNWJwE/b.5385163/k.5CDC/HCP__Canadian_Neurological_Scale_CNS.htm

SECTION A1 – No Comprehension Deficit

Face:	Ask pt. to smile:
None 0.5	No weakness – 0.5
Present 0.0	Weakness – 0.0 (Record L or R)
Arm: Proximal	Ask pt. to lift arms to shoulder level and apply resistance above elbows bilaterally
None 1.5	No weakness – 1.5
Mild 1.0	Movement to 90°, unable to oppose pressure – 1.0
Significant 0.5	Movement < 90° – 0.5
Total 0.0	Absence of motion – 0.0
Arm: Distal	Ask pt. to bend wrist back. Apply pressure on back of the hand.
None 1.5	No weakness – 1.5
Mild 1.0	Can bend wrist, unable to oppose pressure – 1.0
Significant 0.5	Some movement of fingers – 0.5
Total 0.0	Absence of movement – 0.0
Leg: Proximal	Ask pt. to flex knee to 90°. Push down on each thigh one at a time.
None 1.5	No weakness – 1.5
Mild 1.0	Can lift leg, unable to oppose pressure – 1.0
Significant 0.5	Lateral movement but no power to lift leg – 0.5
Total 0.0	Absence of movement – 0.0
Leg: Distal	Ask pt. to point toes and feet upward. Push down on each foot one at a time.
None 1.5	No weakness – 1.5
Mild 1.0	Can point foot & toes upward, unable to oppose pressure-1.0
Significant 0.5	Some movement of toes, but cannot lift toes or foot – 0.5
Total 0.0	Absence of movement – 0.0

SECTION A2 – Comprehension Deficit

Face:	Ask pt. to mimic your grin (if unable, apply pressure to sternum).
Symmetrical 0.5	Symmetrical – 0.5
Asymmetrical 0.0	Asymmetrical – 0.0
Arms:	Demonstrate/place pt. arms in front of pt. at 90° (if unable, apply finger nail bed pressure bilaterally and compare response)
Equal 1.5	Equal motor response – 1.5
Unequal 0.0	Unequal motor response – 0.0 (record L or R)
Legs:	Thighs flexed to 90° (if unable, apply toenail bed pressure bilaterally and compare response)
Equal 1.5	Maintain position or withdraw equally – 1.5

Scoring and Score Interpretation:

• Mentation: Comprised of evaluating consciousness, orientation and speech.
• Motor function evaluations are separated into sections A1 and A2. A1 is administered if the patient is able to understand and follow instructions. A2 is administered in the presence of comprehension deficits (Cote et al., 1986, 1989). Each motor item is rated for severity and each rating is weighted “according to the relative importance of a particular neurological deficit” (Cote et al., 1989).
• It should be noted that assessment using the CNS focuses on limb weakness over other possible neurological impairments (Muir, Weir, Murray, Povey & Lees, 1996).
• The CNS scores only the motor strength of the weakest limb. For patients with a comprehension deficit, asymmetry in strength is scored. Therefore, in addition to using the CNS, clinicians may wish to further evaluate and document the upper and lower extremity strength and power in patients with comprehensive deficit (O’Farrell & Yong Zou, 2008).
• Scores from each section are summed to provide a total score out of a possible 11.5. Lower scores are representative of increasing severity.

Nilanont et al. (2010) developed and validated a conversion model that allows clinicians and researchers to predict NIHSS scores for patients based on their CNS score in order to allow for comparability between the two scales. CNS scores can be reliably converted into NIHSS scores using the following conversion: NIHSS = 23 – (2 x CNS score).

Time:

The CNS takes approximately 5 to 10 minutes to complete (Cote et al., 1986, 1989; O’Farrell & Yong Zou, 2008).

Training requirements:

It is advised that the CNS be completed by a healthcare professional trained in its administration. The CNS does not need to be completed by a neurologistThis team member is responsible for “the diagnostic evaluation, medical treatment, prevention of stroke recurrence, patient and family education, staff and trainee education, research, program evaluation.”(Suggested by Philips et al, 2002)
.

A trained observer rates the patent’s ability to answer questions and perform activitiesAs defined by the International Classification of Functioning, Disability and Health, activity is the performance of a task or action by an individual. Activity limitations are difficulties in performance of activities. These are also referred to as function.
. Training is minimal and is available through participationAs defined by the International Classification of Functioning, Disability and Health, participation is an individual’s involvement in life situations in relation to health conditions, body functions or structures, activities, and contextual factors. Participation restrictions are problems an individual may have in the manner or extent of involvement in life situations. More in a 2-hour workshop or a self-directed learning package and review video. For more details on training requirements please visit the following website: http://www.heartandstroke.on.ca/site/c.pvI3IeNWJwE/b.5385163/k.5CDC/HCP__Canadian_Neurological_Scale_CNS.htm

Subscales:

The subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
items encompass level of consciousness, orientation, speech, motor function and facial weakness.

Equipment:

None typically reported.

Alternative forms of the assessment

None typically reported

Client suitability

Can be used with:

• Patients in the acute phase of strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More who are either alert or drowsy (Cote et al., 1986).

Should not be used with:

• As the CNS was designed as an observational scale, measurement by self-report or by telephone is not possible.

Languages of the measure

None reported.

Summary

What does the tool measure?	The CNS measures neurological status.
What types of clients can the tool be used for?	Patients with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More in the acute phase who are either alert or drowsy.
Is this a screeningTesting for disease in people without symptoms. or assessment tool?	Assessment
Time to administer	Approximately 5 to 10 minutes.
Versions	There are no alternative versions reported.
Other Languages	No information reported.
Measurement Properties
ReliabilityReliability can be defined in a variety of ways. It is generally understood to be the extent to which a measure is stable or consistent and produces similar results when administered repeatedly. A more technical definition of reliability is that it is the proportion of “true” variation in scores derived from a particular measure. The total variation in any given score may be thought of as consisting of true variation (the variation of interest) and error variation (which includes random error as well as systematic error). True variation is that variation which actually reflects differences in the construct under study, e.g., the actual severity of neurological impairment. Random error refers to “noise” in the scores due to chance factors, e.g., a loud noise distracts a patient thus affecting his performance, which, in turn, affects the score. Systematic error refers to bias that influences scores in a specific direction in a fairly consistent way, e.g., one neurologist in a group tends to rate all patients as being more disabled than do other neurologists in the group. There are many variations on the measurement of reliability including alternate-forms, internal consistency , inter-rater agreement , intra-rater agreement , and test-retest .	Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More: One study examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More of the CNS and reported excellent internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More. Inter-rater: Two studies investigated the inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept. and found adequate to excellent inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept. .
ValidityThe degree to which an assessment measures what it is supposed to measure.	Criterion: Concurrent: One study evaluated the concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.” of the CNS and found excellent concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.” between the CNS and global neurological examination. Predictive: Two studies evaluated the predictive validityA form of criterion validity that examines a measure’s ability to predict some subsequent event. Example: can the Berg Balance Scale predict falls over the following 6 weeks? The criterion standard in this example would be whether the patient fell over the next 6 weeks. of the CNS and found initial CNS scores to predict death within 3 to 6 months, morbidity, and recovery of ADL within 3 to 5-months. Construct: Discriminant: One study evaluated the discriminant validityMeasures that should not be related are not. Discriminant validity examines the extent to which a measure correlates with measures of attributes that are different from the attribute the measure is intended to assess. of the CNS and found excellent correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases – for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases – for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation. between total CNS scores and standard neurological examinations.
Floor/Ceiling Effects	Floor/ceiling effects have not yet been examined.
Does the tool detect change in patients?	The CNS can be used to monitor change in neurological status in patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More.
Acceptability	The CNS is short and simple. Patient burden associated with its use should be minimal.
Feasibility	A trained healthcare professional should administer the CNS. It may be used both prospectively and retrospectively.
How to obtain the tool?	The CNS is available from strokecenter.org. A full version of the measure can be found in the following article: Cote, R., Hachinski, V., Shurvell, B., Norris, J. & Wolfson, C. (1986). The Canadian Neurological Scale: A preliminary study in acute stroke. Stroke, 17(4), 731-737.

Psychometric Properties

Overview

For the purposes of this review, we conducted a literature search to identify all relevant publications on the psychometric properties of the CNS.

Floor/Ceiling Effects

Floor/ceiling effects have not yet been examined.

Reliability

Internal ConsistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More:
Cote et al. (1986) examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More of the CNS in 34 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. Four raters (one neurologistThis team member is responsible for “the diagnostic evaluation, medical treatment, prevention of stroke recurrence, patient and family education, staff and trainee education, research, program evaluation.”(Suggested by Philips et al, 2002)
, one resident in neurology and two nurses) evaluated the patients. Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More, as calculated using Cronbach’s alpha, was excellent for all domains (leg weakness 0.896; facial weakness 0.934; distal arm weakness 0.969; orientation 0.979; proximal arm weakness 0.98; and speech 1.00). No differences between professionals were found.

Test-retest:
Test-retest reliabilityA way of estimating the reliability of a scale in which individuals are administered the same scale on two different occasions and then the two scores are assessed for consistency. This method of evaluating reliability is appropriate only if the phenomenon that the scale measures is known to be stable over the interval between assessments. If the phenomenon being measured fluctuates substantially over time, then the test-retest paradigm may significantly underestimate reliability. In using test-retest reliability, the investigator needs to take into account the possibility of practice effects, which can artificially inflate the estimate of reliability (National Multiple Sclerosis Society).
has not been reviewed.

Intra-rater:
Intra-rater reliabilityThis is a type of reliability assessment in which the same assessment is completed by the same rater on two or more occasions. These different ratings are then compared, generally by means of correlation. Since the same individual is completing both assessments, the rater’s subsequent ratings are contaminated by knowledge of earlier ratings.
has not been examined.

Inter-rater:
Cote et al. (1986) examined the inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
of the CNS in 34 patients with acute strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More. Four raters (one neurologistThis team member is responsible for "the diagnostic evaluation, medical treatment, prevention of stroke recurrence, patient and family education, staff and trainee education, research, program evaluation."(Suggested by Philips et al, 2002)
, one resident in neurology and two nurses) evaluated the patients within two to four hours of each other using the CNS. Inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
, as calculated using kappa statistics, was adequate to excellent for all domains (leg weakness 0.722-0.842; facial weakness 0.535-1.00; distal arm weakness 0.758-0.974; orientation 0.744-1.00; proximal arm weakness 0.788-1.00; and speech 0.934-1.00).

Brushnell, Johnston and Goldstein (2001) looked at the retrospective inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
scoring of both the CNS and the National Institute of Health StrokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More Scale (NIHSS). They compared data from academic medical centers to data from community hospitals with neurologists and community hospitals without neurologists. Inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
for the CNS, as calculated using Intraclass correlation coefficient (ICC)Intraclass correlation (ICC) is used to measure inter-rater reliability for two or more raters. It may also be used to assess test-retest reliability. ICC may be conceptualized as the ratio of between-groups variance to total variance., was found to be excellent for all charts reviewed (academic medical center ICC=0.97; community hospital with neurologists 0.88; community hospital without neurologists 0.78). The inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
for the NIHSS was excellent for the charts reviewed from the academic medical centre and the community hospital with a neurologistThis team member is responsible for "the diagnostic evaluation, medical treatment, prevention of stroke recurrence, patient and family education, staff and trainee education, research, program evaluation."(Suggested by Philips et al, 2002)
(ICC=0.93; 0.89 respectively), however only adequate agreement was found for charts reviewed from the community hospital without a neurologist (ICC=0.48). More data was missing for the NIHSS in comparison to that missing for the CNS likely due to the fact that the NIHSS requires a more detailed neurological examination. These results suggest that scoring the CNS retrospectively is reliable regardless of whether the medical record contains evaluation material from a neurologistThis team member is responsible for "the diagnostic evaluation, medical treatment, prevention of stroke recurrence, patient and family education, staff and trainee education, research, program evaluation."(Suggested by Philips et al, 2002)
.

Validity

Content :

Content validityRefers to the extent to which a measure represents all aspects of a given social concept. Example: A depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension.
has not been reviewed.

Criterion :

Concurrent:
Cote et al. (1989) evaluated the concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.”
of the CNS in the original validation study involving 157 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. Patients were evaluated by staff neurologists or neurology residents upon admission to the hospital and were classified as either having no, mild, moderate or severe deficit resulting from acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. Nurses then evaluated the patients using the Glascow Coma Scale (GCS) and the CNS. An average interval of 3.71 hours occurred between assessments. Concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.”
was evaluated by correlating CNS item with the appropriate components of the neurological examination, and the total score of the CNS with the global assessment on the neurological examination (no, mild, moderate or severe). Concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.”
, as measured by Spearman rank correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases – for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases – for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
, was found to be excellent between the global neurological examination and the total CNS score (0.775). The concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.”
between the neurological components and CNS was found to be excellent for orientation (0.716), speech (0.691) and weakness (0.767); and adequate for level of consciousness (0.574).

Predictive:
Cote et al. (1989) evaluated the predictive validityA form of criterion validity that examines a measure’s ability to predict some subsequent event. Example: can the Berg Balance Scale predict falls over the following 6 weeks? The criterion standard in this example would be whether the patient fell over the next 6 weeks.
of the CNS in 157 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. Three outcomes were evaluated: 1) death at 6 months; 2) any vascular event within 6 months (for example, MI, CVA or vascular death); and 3) independence in ADL at 5 months or beyond. Initial CNS scores were found to significantly predict death within 6 months, morbidity, and recovery of ADL within 5-months. For patients with scores of ≥ 11, only 2.1% had died at 6 months, 2.1% experienced another vascular event, approximately 90% were independent in ADLS at 5 months or beyond; compared to those that scored <9 initially where 13.2% had died at 6 months, 20.6% experienced another vascular event and <50% were independent in ADLS at 5 months or beyond.

Muir et al. (1996) compared the CNS, National Institute of Health StrokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More Scale (NIHSS) and the Middle Cerebral Artery StrokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More Score (MCANS) to see which scale best predicted good (alive at home) or poor (alive and requiring in care or dead) outcome at 3-months in 373 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. Predictive accuracy of the variables was compared by ROC curves and stepwise logistic regression. Logistic regression showed that the NIHSS added significantly to the predictive value of all other scores. The overall accuracy for the CNS, NIHSS and MCANS as stand alone measures was adequate (0.79, 0.79 and 0.83 respectively).

SensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
/Specificity:
The sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also "Specificity."
/specificity has not been examined.

Construct :

Convergent/Discriminant:
Cote et al. (1989) evaluated the discriminant validityMeasures that should not be related are not. Discriminant validity examines the extent to which a measure correlates with measures of attributes that are different from the attribute the measure is intended to assess.
of the CNS and the Glascow Coma Scale (GCS) by comparing results with a standard neurological examination. Results from the GCS and the CNS evaluation of 157 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More were compared with a standard neurological examination. Excellent correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases – for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases – for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
was found between the total CNS score and the standard neurological examination (r2=0.769), however only adequate correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases – for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases – for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
was found between the GCS and the standard neurological examination (r2=0.563). These results suggest that the CNS may better discriminate neurological deficit.

Known Groups:
The known groups validityKnown groups validity is a form of construct validation in which the validity is determined by the degree to which an instrument can demonstate different scores for groups know to vary on the variables being measured.
has not been examined.

Responsiveness

Cote et al. (1989) evaluated the responsivenessThe ability of an instrument to detect clinically important change over time.
of the CNS in 79 patients with acute strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. The CNS was administered on admission and throughout the first 48 hours. Patients were classified as either 1) remaining stable over first 48 hours or 2) status changed over first 48 hours. A change in score ≥ 1 yielded the highest negative predictive value (0.969), with a sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of 0.933 and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of 0.508). The results of this study suggest that the CNS can be used to monitor clinically significant differences in neurological status.

Hagen, Bugge, and Alexander (2003) examined the responsivenessThe ability of an instrument to detect clinically important change over time.
of the CNS and other commonly used outcome measures in 136 patients in the early post-stroke period. The outcomes measures were administered at 1, 3 and 6 months after strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More onset. The sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of the CNS to detect change from 1 to 3 months and 3 to 6 months, as calculated using Standardized Response MeanThe standardized response mean (SRM) is calculated by dividing the mean change by the standard deviation of the change scores.
, was small (SRM=0.2860 and 0.2849 respectively). These results suggest that the CNS has some ability to detect change in patients with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More in the subacute phase of recovery.

References

• Bushnell, C.D., Johnston, D.C.C. & Goldstein, L. B. (2001). Retrospective assessment of the initial stroke severity: Comparison of the NIH Stroke Scale and the Canadian Neurological Scale. Stroke, 32, 656-660.
• Cote, R., Battista, R.N., Wolfson, C., Boucher, J., Adam, J., Hachinski, V. (1989). The Canadian Neurological Scale: Validation and reliability assessment. Neurology, 39, 638-643.
• Cote, R., Hachinski, V., Shurvell, B., Norris, J. & Wolfson, C. (1986). The Canadian Neurological Scale: A preliminary study in acute stroke. Stroke, 17(4), 731-737.
• Cuspineda, E., Machado, C., Aubert, E., Galan, L, Liopis, F, Avila, Y. (2003). Predicting outcome in acute stroke: A comparison between QEEG and the Canadian Neurological Scale. Clinical Electroencephalography, 34(1), 1-4.
• Muir, K.W., Weir, C.J., Murray, G.D., Povey, C., Lees, K.R. (1996). Comparison of neurological scales and scoring systems for acute stroke prognosis. Stroke, 27, 1817-1820.
• Nilanont, Y., Komoitri, C., Saposnik, G., Cote, R., Di Legge, S., Jin, Y. et al. (2010). The Canadian Neurological Scale and the NIHSS: Development and validation of a simple conversion model. Cerebrovascular Disease, 30(2), 120-126.
• Shinar, D., Gross, C.R., Mohr, J.P., Caplan, L.R., Price, T.R., Wolf, P.A. et al. (1985). Interobserver variability in the assessment of neurologic history and examination in the stroke data bank. Archives of Neurology, 42, 557-565.

See the measure

How to obtain the CNS?

The CNS is available from strokecenter.org.

A full version of the measure can be found in the following article: Cote, R., Hachinski, V., Shurvell, B., Norris, J. & Wolfson, C. (1986). The Canadian Neurological Scale: A preliminary study in acute stroke. Stroke, 17(4), 731-737.

A training video has been produced by the Heart & StrokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More Foundation of Canada using the Canadian Neurological Scale.