Alright, so we've covered all of the motor stuff, it's time to move on to the next tier of
sensory processing. We've talked before about assessing for vibration sense and
proprioception, etc., the cortex needs to take all that information that's coming in and
integrate it and make sense of it. And so, this next set of tests are designed to assess
cortical sensation, so called cortical sensation as opposed to the peripheral vascular system
with proprioception, etc. So what we're going to have our patient do is do 3 quick tests to
make sure that specifically the parietal lobes are integrating all that information that's
coming up from the spinal cord. First one we'll do is called stereognosia. Alright, so for
stereognosia I'm going to basically have you close your eyes and put out your left hand.
"And I just want you to try and identify what that is in your hand." "It's a house key?"
"Perfect, that is a key. And now give me your right hand. And see if you can identify what
that is." "A quarter?" "Perfect. Now you got exactly not that it's just a coin but actually that
is a quarter, so that's perfect." So, the ability to take all the information and sensory
information and process it is the work of the parietal lobe and that tells me that that is
functioning well. And now they're great, that's called stereognosia, the next one is called
graphesthesia. "Can I have your left hand again? And I'm going to draw a letter or a number
and I want you to see if you can identify what it is." "Number 3." "Perfect. Your right hand."
"Is that a plus sign?" "Perfect." So, that's graphesthesia. And the last one we'll do to assess
for parietal lobe function is called extinction and what I'm simply doing is oftentimes if there
are descent inputs to both hemispheres but one is deceased in some way you may be able to
process sensory information if there are no distractions but if you sample both sides at the
same time the dominant parietal lobe will detect a sensation whereas the other lobe may
may not be able to detect it. "So, can you feel this?" "Eyes closed?" "Eyes closed, sorry."
"Can you feel this on the left?" "Yes." "Can you feel this on the right?" "Yes." "Can you feel it
on both sides?" "Yes." So, a patient who is having a subtle stroke or subtle problem with the
parietal lobe or even the sensorimotor strip on either side may have extinction, that is
sensory extinction. When you apply stimulus to both sides, they are no longer able to feel it
on the affected side. With that, we can move on to higher cortical processing having just
done cortical sensation. We're going to just touch on higher cortical functioning, executive
functioning in so far as we're talking about tests for dementia and for delirium. Now for
dementia, there is a variety of well-validated, widely disseminated instruments that you can
find online in our all part of downloadable material such as the Folstein's Mini-Mental Status
Exam, the Mini-Cog, the Montreal Cognitive Assessment, and even just the clock drawing
test. I'm not going to go into these or demonstrate these because they are essentially a
script that you walk through, anybody could walk through them, it's very straightforward.
They're also available in almost every language on the planet and so I just invite you to
familiarize yourself with those particular instruments because they are very useful validated
tools to assess for early or advanced dementia and staging dementia over time. For delirium,
there is also a variety of tools that are out there. It is a clinical bedside diagnosis and the
tool that I often use is the confusion assessment method, the CAM. And it has only 4
components and the patient has to have 3 out of those 4 components to meet the criteria
for delirium. The first 2 are required components. And that is the patient's mental status
should be acutely changed and fluctuating. So this is not something where the person has had
a slowly indolent progression of memory loss or what have you over the span of weeks or
months. Delirium is, by its nature, a fluctuating mental status. Secondly, the patient should
have problem with attention. So if I said to you "I want you to close your left eye and wiggle
your right finger while tapping your left toe." That's a very complicated, coordinated task.
He requires some degree of attention to be able to do that. A patient with delirium is not
going to be able to attend to things in that way so you have to have both of those criteria,
the fluctuating acute mental status change and a problem with attention and then either of
the next 2 findings. So, one would be disorganized thinking and that's simply if I ask him to
tell me why he is in the hospital or tell me some other piece of information if he's tangential,
not making sense, can't follow his own line of thinking, that would be evidence of disorganized
thinking. And then the last thing would be altered level of consciousness. So if the patient is
having trouble staying awake if I have to do a sternal rub or what have you to wake him up
again, either of those 2 things would be that 3rd criteria and it's necessary for the confusion
assessment method. And that's the full assessment of delirium.