Oral Version of the Trails Test for Cognitive Impairment

When I was a junior resident, I encountered a delirious patient while I was rotating on the general psychiatry inpatient unit at the Veterans Administration Hospital. He carried a diagnosis of Bipolar Affective Disorder and had been admitted because he was thought to be manic. He was elderly and had been taking the usual cocktail of mood stabilizers (including but not limited to Lithium) and antipsychotics in what seemed like a futile effort by his outpatient psychiatrist to protect him from severe mood episodes.

At first he seemed to talk fast and seemed overly ebullient like most of the few patients with mania I’d seen so far in the first year of my residency. But he also stopped eating and drinking and eventually, he started mumbling incoherently and started to refuse his Lithium. The nurses all knew him pretty well and guessed that his mania was worsening and insisted on trying to force his Lithium past his teeth.

Now that truly was an exercise in futility. I remember the pink goo of smashed Lithium tablets around his clenched teeth and saying over and over, “I’ll take the Lithium, I’ll take the Lithium, I’ll take the Lithium!” as he steadily became less connected with us and his environment.

My senior resident and I began to think he was delirious and called the internal medicine consultation team. I remember the resident being an arrogant fellow who clearly was disdainful of having to come to the psychiatry inpatient unit and dismissed our patient as being mentally ill. He managed to convey the impression that we were not very bright because, clearly this man’s problem was his psychiatric illness—mainly because he was admitted to the psychiatric ward. He also obviously wanted no part of going to the trouble of transferring a “psych patient” out to the internal medicine ward.

My senior resident, in a desperate effort to prove her hunch that our patient was delirious conducted an oral form of the Trails A and B test for executive function. This is a subtest of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). First she asked him to count from 1 to 7; then she asked him to recite the letters of the alphabet from A to J. She then asked him to try reciting those letters in alternating sequence. Of course he failed miserably and was eventually transferred to internal medicine. Now, the Trails is actually a paper and pencil test and it looks like a dot to dot game, like the example below:

Trails A and B

My senior resident told me she learned the oral Trails test from her senior resident and couldn’t remember anything else about it. I have used that version for years as a quick test for delirium which I openly taught to my residents—that is until one of my neuropsychologists found out about it. It was an indirect discovery which didn’t trace back to me. He openly criticized it and called it invalid, effectively saying it was a corruption of the original Trails A and B. Of course, after the residents told me about that, I took the obvious next step. I went underground. I still did the test and I still taught the residents the form that I was taught, but I asked that they not discuss it with anyone in our neuropsychology division. And I searched in vain (though admittedly not very strenuously) for years for some kind of documentation of the “verbal Trails” in the medical literature.

It wasn’t until just a few days ago that I finally found it [1]. Of course I’ve been doing it wrong. You’re supposed to have the patient count to 25, then recite the letters of the alphabet, then recite the numbers and letters in alternating sequence from 1 to 13 and A to M. More than two errors in pairings indicate cognitive impairment. Try this link to find it, http://consultgerirn.org/uploads/File/trythis/try_this_d3.pdf

There are limitations to the verbal Trails and caution is advised in more recent literature, indicating that there are moderate education effects in older patients and that it may be wiser to use both paper and pencil and oral versions together [2].

Still the search goes on for quick and dirty ways to screen for cognitive impairment in the elderly because this and advanced age are two main risk factors for delirium.

References:

1.            Ricker, J.H. and B.N. Axelrod, Analysis of an Oral Paradigm for the Trail Making Test. Assessment, 1994. 1(1): p. 47-51.

2.            Mrazik, M., S. Millis, and D.L. Drane, The Oral Trail Making Test: Effects of Age and Concurrent Validity. Archives of Clinical Neuropsychology, 2010. 25(3): p. 236-243.

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