The obvious sometimes bears repeating: Sick people have trouble thinking. They may be suffering from a delirium, a dementia or a more subtle disturbance of cognition caused by fever, drugs, infection, inflammation, trauma, hypoxemia, metabolic derangement, hypotension, tumor, intracranial pathology, pain and so forth. All clinicians know this, and psychiatric consultants in the general hospital or the clinic may know it best of all, as they are specifically charged with the assessment of the patient's thought processes.
Yet formal cognitive testing is often difficult because of the threat it poses to the patient's sense of integrity. Of course, it is true that the astute clinician, after history taking, often identifies problems, even makes the correct diagnosis, simply by sitting at the bedside and "chatting" with the patient.
How does this clinician document findings, demonstrate them to colleagues and family members, and track changes in cognition from day to day without alienating the patient? Everyone has his or her methods, of course. I would like to share one of mine.
Administration of the 10-Point Clock Test
Beginning in 1986, a series of authors began to describe the use of different types of clock-drawing tests for the identification of dementia (Shulman et al., 1986; Sunderland et al., 1989; Wolf-Klein et al., 1989; Mendez and Underwood, 1992; Tuokko et al., 1993; Watson et al., 1993; Freedman et al., 1994). Some suggested that these tests might be useful for the detection of delirium (Shulman et al., 1986; Trezepacz and Wise, 1997).
Before I was familiar with the clock-drawing literature cited above, I began administering my own clock test to patients after about 10 years of full-time inpatient hospital consultation work, and after having been scowled at frequently, if not inevitably, by the defensive and cognitively impaired patients whose wits I had endeavored to test by other means.
I told my patients that when people were ill they had trouble concentrating and that I wished to observe their concentration abilities. I traced a four-inch diameter circle in the chart and then asked the patient to write in the numbers that appear in the face of a clock. When they had finished that task, I asked them to make the clock read ten minutes after 11, consciously avoiding mention of the hands of a clock. This is the entire procedure for the administration of the 10-point clock test (Manos and Wu, 1994). Eventually, I produced a clear plastic template, four inches in diameter and divided into eighths, both to trace the circle and score the test.
To score, the clock is divided into eighths, beginning with a line through the number 12 and the center of the circle. (If the 12 is missing, its position is assumed to be counterclockwise from the 1 at a distance equal to that between the 1 and 2.) Any straight edge may be used to divide the clock into eighths. This is accomplished more quickly by placing the clear, flat plastic template over the circle with a line through the number 12.
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