Tuesday, May 29, 2012

Dementia Clocks

Dementia Clocks

The clock drawing test is quite helpful to me as a neurologist but is also often non-specific. That's the first thing I think you should know about this simple test. 

There are many things that can interfere with the ability to draw a clock successfully. I use it in the context of the patient as a whole, their history, what family has to say about how they are doing, other quick cognitive tests; in that way it can be quite helpful and sometimes very specific. If anything, it is often enlightening to the family, as often the family is under-appreciating the level of difficulty thinking/overall processing their loved one is having. This is often because the family, first, loves them and therefore fills in their deficits with the wonderful “blindness” of a loving eye, and, second, is often due to the gradual change in the patient, and since the loved ones are often consistently there, they gradually lose perspective on how far the patient has actually declined.

Because the clock test often requires many different types of thinking at once, it is helpful, often bringing some degree of clarity to the family that things are amiss.

Think about drawing an analog clock face that reads “ten minutes after eleven” with its hands. Try to think back to what it was like to learn to interpret and document time this way as a child. 

The clock drawing test is always the same: Quiet room. No help. No reminders (usually).
The patient is given a pen, blank good-sized paper, all the time they need, and the request to “please draw the face of clock, with all the numbers on it, and please make it show the time ‘ten minutes after eleven.’” Some clinicians (especially if formally scoring the clock on a point system) draw a 10cm diameter circle for the patient and tell them that it represents the face of the clock to begin with. I do this too sometimes, usually in more advanced dementia or sometimes in the hospital for possibly delirious patients.

What’s tested:
General orientation
Conceptualization of time
Visual spatial organization
Executive function
Hearing/Auditory comprehension
Motor programming
Numerical knowledge
Inhibition of distracting stimuli
Frustration tolerance

Sometimes, depending on how a patient responds to the test or performs the this basic test, it can point toward some specific cognitive problem warranting further investigation or resource allocation.

There are actual scoring systems such as the SHULMAN (most common 5 point test), CAMDEX, and excellent formal methods of evaluation by Sunderland et al, and Watson et al. But I find these helpful for research criteria primarily and don’t really help me when evaluating patients as an outpatient for diagnosis and treatment plans.

A general rule of thumb: If someone performs this test without any reminders or guidance and without frequent practice “trials” and without looking at a clock….. (cheating in other words) AND they miss two items (or more of course), then they should be evaluated for some degree of impairment in thinking or cause for some other reason, because that’s not normal. If they draw it right, it doesn’t rule out dementia or more subtle cognitive impairment; it’s just a start.

Studies suggest that if abnormal, it will at least pick up at least 75% of people with dementia successfully, and picks up about 40 to 50% of people with Mild Cognitive Impairment (MCI can be a precursor to dementia later).

A few examples from my patients:

Example 1:  
I saw this patient a few days ago. It is a great example for the fact that not all dementias are Alzheimer’s dementia and, that it may not only affect treatment, but understanding by the family helps with meeting the current and potential future needs of the patient to keep them safe and as comfortable as possible.
During the test, she realized something was wrong with the first drawing, crumpled it up, gave me the evil eye, and threw it on the ground (at me for frustrating her with “stupid things”). She made a second attempt (seen here) and then was about to crumple it up, but I took it first… so she threw her pen at me instead. Now, this is highly atypical for this pleasant woman who is still able to play the organ at her church better than I could ever hope to learn, but it reveals something about her. She came to me with a diagnosis of “mild” Alzheimer’s disease… but she doesn’t have this dementia (Alzheimer's-type) at all in fact, and her behavior seemed at odds with what the family read about Alzheimer’s disease.
And the patient was on specific medications for Alzheimer's which likely will not help her.

Notice that she successfully remembered all the numbers, placed them in the right place and even put different sized hands on the clock.
BUT, she drew them to the 10 and to the 11. This is something called “frontal pull.” When you draw the long hand to the “2” you recognize that as the abstraction of 10 minutes. But if you literally draw the hand to the “10”… you are missing that abstraction and not able to overcome the missed understanding enough to not draw the hand altogether or ask me to repeat the instructions again. When people have problems with the frontal lobes (which helps you think through such things), they are more likely to have frontotemporal dementia (FTD) which is a different type of dementia from Alzheimer’s. Now, this test alone doesn’t tell me that; it also was helpful that she was not able to reign in her frustration (disinhibition) and threw stuff at me, and she also had difficulty with other things like drawing a giraffe and owl, which are slightly unusual animals stored in the temporal lobes of the brain (remember: fronto-temporal dementia). But this clock drawing test was helpful toward redirecting her care.

Alzheimer's footnote:
Depending on far along they are, they may have any number of errors. In a different patient with Alzheimer's, a few common problems that help point toward this type of dementia: They often will need to have the clock drawing test request repeated because they forget the series of commands before completing them, or distract themselves into forgetting them as they start the test. They may start counter-clockwise, leave out numbers, or have the spacing between numbers off, or draw the entire clock f ace too small to begin with before trying to place numbers. Often earlier in this dementia they will realize something is wrong and attempt to self-correct or because slightly flustered if they can’t correct it. In other words, they may retain some degree of insight that something is wrong. As it progresses, the patient will lose insight into the fact that they are amiss in their attempt and the errors will add up.

Example 2:

I saw this patient yesterday, Memorial Day. She and I were unfortunately both spending the holiday within the fluorescent-lit world of the hospital. She, however, was ill, but not with dementia. She had a Urinary Tract Infection, one of the most common causes of altered mental status in elderly women. This woman has delirium. You can see here that she drew all the numbers in mostly the right place, and tried to get her clock divided up into quarters correctly by drawing lines, and realizing her quartering line to the bottom was slightly "off," tried to draw a little line at the bottom bringing it to the 6. And she actually did get the basic "10 minutes after 11" concept, but the hands aren't placed very well. And she also drew the number "10" in the top right corner randomly during the attempt, and also drew something (perhaps a clock base?) at the bottom.
So, overall, she did everything right, just slow. As a general rule, she could have drawn ANYTHING, and it would have been consistent with delirium. The moral of this example is that a clinician should never diagnose dementia in the hospital.... since delirium can be caused by a very long list of things and also affect clock drawing.

Example 3: 

Now in this patient, he already has established moderate-to-severe Alzheimer’s dementia, and I guided him through the test, so you can see how this improved performance.
Trail 1: Notice that he at first draws more of a watch setup after he quickly wrote the numbers “10” and “11.” I smiled at this because I get it.
Somewhere inside, he realizes he’s going to have trouble, so he either wrote the numbers as quickly as possible after I said the instructions so as not to forget them, or he wrote them down so that he could “de-abstract” them by writing them. Either way, by the time it came to actually writing numbers, he could not decide how to start, and then kind of lost track of the objective and looked up at me pleadingly for assistance.
Trial 2: With his next attempt, he still has trouble planning the clock face size to be able to put in numbers and then continues to have difficulty, and cannot remember the instruction to draw the numbers when it comes to that point.
Trial 3: By now, he’s heard the instructions about 5 times, and I walked him through step-by-step to see if he would be able to recognize that “10 minutes after” should be represented in abstraction by the “2.” I was pleased that he was still able to do this eventually, even if strong guidance was needed. That fact, in and of itself, was helpful for the family present to know.

Example 4:

Lastly, I just wanted you to see a post-stroke patient of mine's clock: (I drew the circle for this patient to begin the test)

This patient had a stroke on the right side, in the back part of their brain. They did not lose vision but, instead had something called neglect. They literally neglect (ignore) the left half of their world (right side of brain usually affects the left side). A person who cannot see the left side of their world might draw a warped clock and complain of the cut in their vision or try to “bend” the shape of the clock to keep it in view. They are often at least indirectly aware that something is wrong on that side, even if they can’t define it (since the brain tries to fill it in for you). A person who neglects the left half of their world, just leaves it out as if it is irrelevant. They don’t seem to mind…. Because the very part of them that has the ability to care (the brain) is itself damaged. I confess it is an unusual concept (and a slightly philosophical concept) to wrap our thinking around, but it’s part of the way we are wired as humans.

In this patient, you can see him struggling to put the 8 in the part of his vision he is beginning to neglect, and kind of realizes that the hour hand should go toward an "11" which doesn't exist in his world... a world he finds "irrelevant" because his mind is ignoring it... even though he "knows" that the hour hand should go this direct somehow. I don't believe you or I can ever truly understand the mini-dilemma he is facing: trying to internally remedy working into a world he is neglecting (with the hour hand) from a part of the brain which is damaged, against the non-damaged part of the brain which tells him it should be there.

Why it was helpful in this patient: they wanted to drive and their family did not know how to say no because the patient seemed so “normal” and have normal conversations with everyone. At home they only seem to bump into things at times and stopped using their left hand as much as before even though it seems strong when they do use it. By showing, with this simple test, that the family member is ignoring most of the left half of their world… it can easily be seen that this person would not (could not) make appropriate nor safe driving decisions.