King Devick Test | Assessing Oculomotor Function

King Devick test is a valuable diagnostic tool for the assessment of oculomotor function, particularly in cases of concussions and other neurological disorders. Originally developed in the 1970s as a screening mechanism for identifying learning disabilities in young people, the King Devick test has evolved to become a cornerstone in the detection of subtle cognitive and visual scanning impairments. Its utility in clinical settings, particularly for healthcare professionals specializing in neurology, sports medicine, and rehabilitation, cannot be overstated.

See Also: Cognitive Tests & Assessments

How to do the King Devick Test?

The King Devick test is a straightforward, yet effective, visual scanning test that typically takes between 2 to 3 minutes to administer. It involves the patient reading a sequence of numbers as quickly as possible from three different cards, with each card designed to progressively increase in visual difficulty. This is achieved through variations in the spacing of the numbers. Before the test begins in earnest, the patient is shown a demonstration card to familiarize them with the task ahead.

Patients are required to read rows of single-digit numbers from left to right without making errors, while the examiner times the completion of each card. The total time taken to read all three test cards is recorded, alongside the number of errors made. This time-sensitive nature of the test is crucial for assessing the efficiency and accuracy of the patient’s visual scanning abilities.

Clinical Relevance

The King Devick test is particularly relevant in the context of acute concussions and other neurological disorders that may impact cognitive function and visual scanning abilities, such as saccadic rhythm and language comprehension. By comparing the test results to baseline assessments typically obtained during preseason evaluations for athletes, healthcare professionals can determine if there has been a deterioration in performance indicative of a concussion or other neurological impairments.

It is important to note that concussed athletes often exhibit a significant increase in the time required to complete the test, usually taking 5 to 7 seconds longer than normal. This highlights the sensitivity of the King Devick test in detecting even subtle changes in cognitive and visual scanning functions following a concussion.

Limitations and Considerations

While the King Devick test is a valuable tool in the assessment of oculomotor function, it does not evaluate other critical aspects such as pursuit, convergence, or accommodation, which are also important to consider when diagnosing concussions. Furthermore, the test is subject to a learning effect, which may limit its usefulness for serial assessments over time. Therefore, it should be utilized as part of a comprehensive neurological examination that includes additional tests to assess these other domains.

Conclusion

The King Devick test is an essential component of the neurological assessment toolkit, offering healthcare professionals a quick and effective means of evaluating oculomotor function in patients. Its application extends beyond the identification of learning disabilities, providing critical insights into the subtle cognitive and visual scanning impairments associated with concussions and other neurological disorders. Despite its limitations, when used judiciously and as part of a broader assessment strategy, the King Devick test can significantly aid in the timely diagnosis and management of patients with neurological impairments.

References & More

1. Orthopedic Physical Assessment by David J. Magee, 7th Edition.
2. Galetta KM, Barrett J, Allen M, Madda F, Delicata D, Tennant AT, Branas CC, Maguire MG, Messner LV, Devick S, Galetta SL, Balcer LJ. The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters. Neurology. 2011 Apr 26;76(17):1456-62. doi: 10.1212/WNL.0b013e31821184c9. Epub 2011 Feb 2. PMID: 21288984; PMCID: PMC3087467. Pubmed