What is Executive Dysfunction?

Executive cognitive function is an interrelated set of abilities that includes cognitive flexibility, concept formation, and self-monitoring. Frontal subcortical brain changes associated with vascular disease, late-onset depression, frontal dementia, or advanced Alzheimer’s disease (AD) are among the most common causes of executive dysfunction in late life. With impaired executive dysfunction, instrumental activities of daily living, such as paying bills, shopping, medication management, and driving, may be beyond the person’s capacity despite only mild memory impairments. The person’s capacity to exercise self-control and to direct others to provide care may also be diminished.¹ Executive dysfunction is one element in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition² criteria for the diagnosis of dementia and occurs in all dementing diseases. Executive dysfunction may be a more robust predictor of nursing home admission than memory impairment.³

Assessment of Executive Dysfunction

Assessing executive function can help determine a patient’s capacity to execute healthcare decisions⁴ and discharge plans⁵ and to live in the community without assistance.⁶ The presence of executive dysfunction also has prognostic implications for mood disorders. Executive deficits may prevent the recovery of independence even when the mood disorder of a major depressive episode has been successfully treated.⁷ And because learning and memory may be preserved despite the executive dysfunction of late-onset depression, problem-solving therapy offers the promise of training the patient to overcome the associated disability. As a result, the assessment of executive dysfunction should be part of the mental status examination for both dementia and depression. The following brief screening tests of executive function can be administered in the office or at the bedside.

Controlled Oral Word-Association Test

With categories beginning with the letter “F,” then “A,” then “S,” the Controlled Oral Word Association Test by Spreen and Benton⁸ requires respondents to fill the category by providing words of three or more letters. For example, correct responses to the category cue “F” would include fish, foul, fact, etc. This test reflects abstract mental operation related to problem solving, sequencing, resisting distractions, intrusions, and perseverations. It is considered a “frontal” task as the organization of words by first letter is unfamiliar, and requires conscious, effortful, systematic organization and the filtering of irrelevant information such as natural taxonomic categories. Patients who are free of executive dysfunction will produce 10 words within 60 seconds in each category for a total of 30 words in 3 minutes. The physician allows 1 minute for the patient to provide the list before moving to the next category. Typical errors include repetitions and intrusions of words from one category to the next, and inability to meet the 10-word goal in the second and third categories.

Trailmaking Test—Oral Version

The oral version of the Trailmaking Test⁹ requires the subject to count from 1 to 25 and then recite the 24 letters of the alphabet. For testing the subject is asked to pair numbers and letters eg, “1-A, 2-B, 3-C, etc.” until the digit 13 is reached. This version does not make visual scanning or visually guided motor demands. However, the individual is required to keep the number and letter sequences in working memory so as not to lose place. More than two errors in 13 pairings is considered impairment.

Clock Drawing

In this test, the physician asks the patient to draw a clock showing the time as 1:45 and to set the hands and numbers on the face so that a child could read them. Once the task is complete, the physician draws a clock with a 2-inch diameter, with all the numbers in place, and the hands set at 1:45. Then the patient is asked to copy it. An unimpaired person will draw a round figure with the following elements: recognizable circle at least 1 inch in circumference with all the numbers present and in correct, symmetrical sequence. There will be two hands anchored in the center pointing to the correct time. If any of the above elements are missing the person is possibly impaired. If more than one is missing the person is probably impaired. Intruded elements, such as words or letters, indicate impairment. Persons with only executive dysfunction will exhibit errors on the first clock but not the second. Those with both executive function and construction apraxia, usually as a result of moderate AD or stroke, will fail both.¹⁰

A validated Spanish version of the CLOX is also available. For complete versions write to: Donald R. Royall, MD, Department of Psychiatry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, TX 78284-7792.

Category Fluency

In the test of category fluency, the patient is asked to make up an imaginary grocery list with anything he or she might buy in the supermarket. The physician allows 1 minute for the patient to provide the list before moving to the next category. Unimpaired persons will generate 9–10 words in 1 minute from each category. Persons with executive dysfunction will have difficulty staying on task and intrude items from the interview or extraneous categories.¹¹

Case Study

A man in his late 70s and his wife were admitted to a teaching hospital via the emergency medical service. The man told the emergency medical technicians that his loss of “power in the legs” was of sudden onset and he could not care for his wife who suffered from AD. The admitting physicians found his wife’s hygiene, nutrition, and hydration deficient and she could not participate in any treatment decision making. The patient initially allowed the physicians to draw his blood and perform physical examinations which demonstrated mild diabetes and extension muscle atrophy of the lower extremities. He was alert, loquacious, articulate, but soon became adamant that he and his wife be discharged. He refused further diagnostic procedures and maintained that with time he would be able to walk and care for all his wife’s needs. He said that “if and when” he needed help, he would find it without the assistance of the hospital social worker. The physicians doubted his ability to provide for his wife and were perplexed by his refusals. When asked to participate in a conference with a geriatric specialist to address the problem of discharge he enthusiastically agreed.

The patient eagerly recounted his college education and successful career as a chef. He and his wife had married late in life and shortly thereafter his wife developed AD. She had previously been admitted to a nursing facility but the care was so poor that he took her home to care for her with the assistance of a health aide. However, he also found fault with the first and 14 subsequent aides and decided to care for her without assistance. He admitted that the turnover in aides was partly his fault but that their inadequate training in AD was the deciding factor. He maintained his determination to return home with his wife and were it not for his inability to stand, his certainty and clarity of mind would have been convincing. He agreed to a physiatric assessment and said that if physical therapy could not accelerate his recovery he might consider a home health aide.

After he refused physical therapy the psychiatrist came to his bedside to address the impasse and gained permission to test his memory which he had declined in the initial encounter. His vocabulary was superior and he had no difficulties with object identification. He was able to repeat a memory phrase with ease and after a 5-minute delay, recall 3 of 5 items. However, he could not accurately complete more that one subtraction by serial sevens. When asked to recite a grocery list he generated 11 items in 60 seconds. He was able to copy the examiner’s clock drawing but could not get beyond the drawing of a circle when asked to draw a clock with the time set at 1:45. He provided seven examples when asked to generate a list of words starting with the letter “F.” However, in response to the category prompt “A” he listed only five words one of which was an intrusion from the previous category. For the “S” category he generated only three words.

The psychiatrist advised him that under the circumstances his physicians were unlikely to agree to discharge and that they would seek a court-appointed guardian to authorize nursing home admission for the couple. The patient had the option of opposing the appointment of a guardian but the process would have prolonged his hospital stay. The physicians completed the documentation necessary for the guardianship application but the patient agreed to nursing home admission prior to the court hearing.

In summary, the patient’s superior education, intact communication skills, and mild memory impairment masked the executive dysfunction which contributed to his lack of insight. He could not appreciate the gravity of his condition or his inability to meet his wife’s needs. As a result, what seemed initially to be bad judgment was more accurately impaired judgment. To have allowed him to return to the community would have been abandonment by his physicians. PP

References

1. Kennedy GJ, Scalmati A. The importance of executive deficits: assessing the older person’s capacity to remain at home. Geriatrics. 2002;57:40-41.

2. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.

3. Royall DR, Cabello M, Polk MJ. Executive dyscontrol: an important factor affecting the level of care received by elderly retirees. J Am Geriatrics Soc. 1998;46:1519-1524.

4. McCullough LB, Molinari V, Workman RH. Implications of impaired executive control functions for patient autonomy and surrogate decision making. J Clin Ethics. 2001;4:397-405.

5. Daly S, Sawchuk PJ, Wertenberger DH. Sending the elderly home. Assessing the risk. The Canadian Nurse. 2000;3:27-30.

6. Cooney LM, Kennedy GJ, Hawkins KA, Hurme SB. Who can stay at home: Assessing the capacity to choose to live in the community. Arch Int Med. In press.

7. Alexopoulos GS, Meyers BS, Young RC, et al. Executive dysfunction and long-term outcomes of geriatric depression. Arch Gen Psychiatry. 2000;3:285-290.

8. Spreen FO, Benton AL. Manual of Instructions for the Neurosensory Center Comprehensive Examination for Aphasia. British Columbia, Canada: University of Victoria; 1977.

9. Ricker JH, Axelrod BN. Analysis of an oral paradigm for the trail making test. Assessment. 1994;1:47-52.

10. Royall DR, Cordes JA, Polk M. CLOX: an executive clock drawing task. J Neurol Neurosurg Psychiatry. 1998;64:588-594.

11. Mattis S. Mental status examination for organic mental syndrome in the elderly patient. In: Bellak L, Kerasu TB, eds. Geriatric Psychiatry: A Handbook for Psychiatrists and Primary Care Physicians. New York, NY: Grune and Stratton; 1976:79-121.

Disclosure: Dr. Kennedy has received grant support from AstraZeneca, Eli Lilly, Forest, Janssen, and Pfizer.