Single Letter Cancellation Test (SLCT)

Evidence Reviewed as of before: 19-08-2008
Author(s): Lisa Zeltzer, MSc OT; Anita Menon, MSc
Editor(s): Nicol Korner-Bitensky, PhD OT; Elissa Sitcoff, BA BSc

Purpose

The Single Letter Cancellation Test (SLCT) is used to evaluate the presence and severity of visual scanning deficits, and is used to evaluate unilateral spatial neglect (USN) in the near extra personal space (Diller, Ben-Yishay, Gertsman, Goodkin, Gordon, & Weinberg, 1974).

In-Depth Review

Purpose of the measure

The Single Letter Cancellation Test (SLCT) is used to evaluate the presence and severity of visual scanning deficits, and is used to evaluate unilateral spatial neglect (USN) in the near extra personal space (Diller, Ben-Yishay, Gertsman, Goodkin, Gordon, & Weinberg, 1974).

Available versions

The SLCT was published by Diller et al. in 1974.

Features of the measure

Items:

There are no actual items for the SLCT.

The test consists of one 8.5 x 11 sheet of paper containing 6 lines with 52 letters per line. The stimulus letter H is presented 104 times. The page is placed at the patient’s midline. The patient is told to put a line through each H that is found on the page. The time taken to complete the test is recorded.

Scoring:

The score is calculated by subtracting the number of omissions (H’s that were not crossed out) from the possible perfect score of 104 (0 to 53 on the left and 0 to 51 on the right). Higher scores indicate better performance. Presence of USN can be inferred by calculating the frequency of errors to the left or to the right from the center of the page. Omissions of 4 or more have been found to be pathological (Zoccolotti, Antonucci, Judica, Montenero, Pizzamiglio, & Razzano, 1989). Commissions are rarely seen and are therefore not included in the analyses.

Normative data has been published by sex and age, based on the results from 341 patients with lesions of the right hemisphere (Gordon, Ruckdeschel-Hibbard, Egelko, Diller, Simmens, & Langer, 1984).

Normative data has been published by sex and age, based on the results from 341 patients with lesions of the right hemisphere (Gordon, Ruckdeschel-Hibbard, Egelko, Diller, Simmens, & Langer, 1984).

Time:

Less than 5 minutes.

Training:

None typically reported.

Subscales:

None.

Equipment:

  • 11x 8-inch page of paper containing 6 lines with 52 letters per line and the stimulus letter H presented 104 times (53 times on left, 51 on right).
  • Pencil
  • Stopwatch

Alternative forms of the SLCT

None typically reported.

Client suitability

Can be used with: Patients with stroke.

  • Patients must be able to hold a pencil to complete the test (the presence of apraxia may impair this ability).
  • Patients must be able to recognize letters of the alphabet to complete the test.

Should not be used with:

  • The SLCT cannot be used to differentiate between sensory neglect and motor neglect because it requires both visual search and manual exploration (Ladavas, 1994).
  • The SLCT cannot be completed by proxy.

In what languages is the measure available?

The SLCT has been used with English and French-speak patients.

A Hebrew version of the SLCT has been used in some studies as part of the Behavioral Inattention Test (e.g. Friedman & Nachman-Katz, 2004).

Summary

What does the tool measure? Unilateral Spatial Neglect (USN) in the near extra personal space.
What types of clients can the tool be used for? Patients with stroke.
Is this a screening or assessment tool? Screening.
Time to administer Less than 5 minutes.
Versions None.
Other Languages

The SLCT has been used with English and French-speak patients. A Hebrew version of the SLCT has been used in some studies as part of the Behavioral Inattention Test.

Measurement Properties
Reliability
  • No studies have examined the internal consistency of the SLCT.
  • One study has examined the test-retest reliability of the SLCT and reported adequate test-retest.
Validity

Construct:

Adequate correlation with mean CT-scan damage; adequate to excellent correlations with Albert’s Test , Sentence Reading Test, and the Wundt-Jastrow Area Illusion Test; significant correlation with the Semi-Structured Scale for the Functional Evaluation of Hemi-inattention

Does the tool detect change in patients? Not applicable.
Acceptability The SLCT should be used as a screening tool rather than for clinical diagnosis of USN. Apraxia must be ruled out as this may affect the validity of test results. This test cannot be completed by proxy. Patients must be able to hold a pencil and recognize letters of the alphabet to complete. The SLCT cannot be used to differentiate between sensory neglect and motor neglect.
Feasibility The SLCT requires no specialized training to administer and only minimal equipment is required (a pencil, a stopwatch, and the test paper). The test is simple to score and interpret. A suggested cutoff score for the presence of USN is provided (omissions of 4 or more). The test is placed at the patient’s midline and the time it takes for the patient to complete the test is recorded.
How to obtain the tool?

Please click here to see a copy of the SLCT.

Psychometric Properties

Overview

In general, cancellation tests are believed to have greater test-retest reliability than line bisection tests and are often more sensitive for detecting USN than line bisection tests (Marsh & Kersel, 1993; Azouvi et al., 2002). The SLCT has been reported to have strong psychometric properties, including reliability and validity, in identifying USN in the near extra personal space (Menon & Korner-Bitensky, 2004). For the purposes of this review, we conducted a literature search to identify all relevant publications on the psychometric properties of SLCT.

Reliability

Internal consistency:

No evidence.

Test-retest:

Gordon, Ruckdeschel-Hibbard, Egelko, Diller, Simmens, and Langer (1984) examined the test-retest reliability of the SLCT using a group of 31 subjects and found adequate test-retest (r = 0.63).

Validity

Construct:

Egelko et al. (1988) found that the SLCT correlated adequately with mean CT-scan damage (r = -0.35).
Note: This correlation is negative because a high score on the SLCT indicates better performance, whereas a high CT-scan score indicates more damage.

Zoccolotti, Antonucci, Judica, Montenero, Pizzamiglio, and Razzano (1989) found that correlations between the SLCT and other visuo-spatial tests (Albert’s Test , Sentence Reading Test, and the Wundt-Jastrow Area Illusion Test) ranged from adequate to excellent (ranging from r = 0.36 to r = 0.69). The SLCT was found to be the most sensitive among these tests in detecting USN (from 4.1% to 25%), which may be due to the high density of stimuli used.

Zoccolotti, Antonucci, and Judica (1992) found that the SLCT correlated with the Extra personal subscale of Semi-Structured Scale for the Functional Evaluation of Hemi-inattention (Kendal’s tau = -0.52).
Note: This correlation is negative because a high score on the SLCT indicates better performance, whereas a high score on the Semi-Structured Scale indicates the presence of USN.

Criterion

No evidence.

Validity

No evidence.

References

  • Azouvi, P., Samuel, C., Louis-Dreyfus, A., et al. (2002). Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke. J Neurol Neurosurg Psychiatry, 73, 160 -166.
  • Diller, L., Ben-Yishay, Y., Gerstman, L. J., Goodin, R., Gordon, W., Weinberg, J. (1974). Studies in scanning behavior in hemiplegia. Rehabilitation Monograph No. 50, Studies in cognition and rehabilitation in hemiplegia. New York: New York University Medical Center, Institute of Rehabilitation Medicine.
  • Egelko, S., Gordon, W. A., Hibbard, M. R., Diller, L., Lieberman, A., Holliday, R., Ragnarsson, K., Shaver, M. S., Orazem, J. (1988). Relationship among CT scans, neurological exam, and neuropsychological test performance in right-brain-damaged stroke patients. J Clin Exp Neuropsychol, 10, 539-564.
  • Friedman, N., Nachman-Katz, I. (2004). Developmental neglect dyslexia in a hebrew-reading child. Cortex, 40(2), 301-313.
  • Gordon, W.A., Ruckdeschel-Hibbard, M., Egelko, S., Diller, L., Simmens, S., Langer, K. (1984). Single Letter Cancellation Test in Evaluation of the Deficits Associated with Right Brain Damage: Normative Data on the Institute of Rehabilitation Medicine Test Battery. New York: New York University Medical Center.
  • Ladavas, E. (1994). The role of visual attention in neglect: A dissociation between perceptual and directional motor neglect. Neuropsychological Rehabilitation, 4, 155-159.
  • Marsh, N. V., Kersel, D. A. (1993). Screening tests for visual neglect following stroke. Neuropsychological Rehabilitation, 3, 245-257.
  • Menon, A., Korner-Bitensky, N. (2004). Evaluating unilateral spatial neglect post stroke: Working your way through the maze of assessment choices. Topics in Stroke Rehabilitation, 11(3), 41-66.
  • Zoccolotti, P., Antonucci, G., Judica, A., Montenero, P., Pizzamiglio, L., Razzano, C. (1989). Incidence and evoluation of the hemi-negelct disorder in chronic patients with unilateral right brain damage. Int J Neurosci, 47, 209-216.

See The Measure

How to obtain the SLCT?

Please click here to see a copy of the SLCT.

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