Lecture 1
Diagnostics
- Diagnostics = the art of distinguishing a disease, the recognition of a disease from its
symptoms.
a) Reason for diagnostic research and research question:
• Knowledge → What are the problems? What goes well and what doesn’t?
• Explanation/diagnosis → Why are certain problems noticeable now, what are
reasons that these remain? What could cause this?
• Prediction → How will the problems develop? What kind of things we can
expect?
• Indication (for treatment) → How can we help the patient with the problem?
What are the strengths and weaknesses?
• Evaluation of treatment → Did the intervention help sufficiently or did the
symptoms change over time (important for neurodegenerative disorders).
b) Formation of hypothesis is based on reason for referral and information already
available (background information), we start the history taking.
- We need more sources of information as that gives greater reliability. Different
sources of information are:
• Anamnesis → information on background (daily life, occupation, marital
status), medical history/diagnosis, effects on daily life; spontaneous
complaints; functioning (normal? gravity problems? since when, and
trajectory – acute/chronic/fluctuating); specific or diffuse problems; mood;
personal circumstances.
• Heteroanamnesis → when the patient can’t communicate adequately; to
check if the picture presented by the patient is adequate; the information can
be very subjective. Is the patient aware of the problems; what is missing in the
information? Effect on social relationships?
c) Choosing the tests → one test usually measures only one function, that is why we
usually need more tests. Beware of the (im)possibilities of the patient (visual
impairment or paresis of dominant hand); which tests? Some tests are more reliable
and valid than others.
• Validity = does the test measure what it is supposed to measure.
• Reliability = do the scores represent actual functioning or is the measure error
too big? Especially important when testing multiple times with the same test!
• Norms (age, sex, level of education)
• In the NL the information on these quality specifics is checked by the
COTAN.
• Repeated testing → In theory, if a score the 2nd time of testing is outside the
confidence interval of the 1st testing; it implies significant difference between
the 2 scores. However, reliability (test – retest) information is often scarce.
Thus, it is often impossible to draw firm conclusion as people who have
multiple testing can learn (practice effect)
• Building the test battery → the test battery should be as short as possible to
not distress the patient more than needed, yet it has to answer the research
question and test the hypothesis.
i. Building the test battery: Fixed battery or flexible (individualized)?
1. Pro's fixed: the standardization means that the whole battery
together has been validated and has norms / easier to compare
, to other patients. - in flexible you don't know what the effects
of the one test on the other are. And simpler: you know what
and when to do.
2. Con's fixed: can you test all your hypotheses, and not do too
much?
ii. Order of the tests. Beware of the following:
1. Interference effects (no verbal learning tests in between
immediate recall and delayed recall of other verbal learning
tests)
2. Some tests use the same pictures
3. Practice effects (thus, spread tests that the measure the same
thing over different time periods)
4. Fatigue (demanding attention tasks schedules when patients are
still “fresh”)
5. Motivation and anxiety (start with relatively easy tasks,
except for those “high functioning patients who want to be
challenged”)
d) Differential diagnosis: symptom ≠ syndrome.
• The Halo effect = when you already believe in your head for something to be
true, and you just collect the evidence to support the idea. → Keep an open
i. mind that it could be all sorts of things, therefore we do the differential
diagnosis.
e) Importance of standardization (also of task instructions, test environment) → stick to
the same script of introducing the instructions! Try to create as clean of an
environment as possible without distractions!
- Observations during testing:
• Physical appearance → is the person able to take care of themselves, are they
groomed, do they smell, do they look age appropriate …
• Contact / rapport → are they cooperative, are they timid, eye contact…
• Understanding of the situation they are in
• Emotional reactions
• Attitude and executive functions
• Sensory functions
• Motor functioning
• Attention & concentration
• Speech & language
• Memory
- Outside of standardization
a) Testing the limits
a. When a patient cannot perform the tests – many reasons as to why may play a
role → You want to figure this out. So it’s important to see what a patient is
able to do (without time pressure), to see if they are able to handle it so it’s
just slow information processing, if they need social reassurance…
b) Disturbing factors may be related to external factors or to the patient
a. Sensory or motor handicaps, being of other ethnical background, depression,
fatigue, pain, anxiety, personality, light aphasia, legal issues (intentionally
underperforming on the tests), substance abuse/withdrawal issues, personality,
insufficient effort/lack of motivation.
Diagnostics
- Diagnostics = the art of distinguishing a disease, the recognition of a disease from its
symptoms.
a) Reason for diagnostic research and research question:
• Knowledge → What are the problems? What goes well and what doesn’t?
• Explanation/diagnosis → Why are certain problems noticeable now, what are
reasons that these remain? What could cause this?
• Prediction → How will the problems develop? What kind of things we can
expect?
• Indication (for treatment) → How can we help the patient with the problem?
What are the strengths and weaknesses?
• Evaluation of treatment → Did the intervention help sufficiently or did the
symptoms change over time (important for neurodegenerative disorders).
b) Formation of hypothesis is based on reason for referral and information already
available (background information), we start the history taking.
- We need more sources of information as that gives greater reliability. Different
sources of information are:
• Anamnesis → information on background (daily life, occupation, marital
status), medical history/diagnosis, effects on daily life; spontaneous
complaints; functioning (normal? gravity problems? since when, and
trajectory – acute/chronic/fluctuating); specific or diffuse problems; mood;
personal circumstances.
• Heteroanamnesis → when the patient can’t communicate adequately; to
check if the picture presented by the patient is adequate; the information can
be very subjective. Is the patient aware of the problems; what is missing in the
information? Effect on social relationships?
c) Choosing the tests → one test usually measures only one function, that is why we
usually need more tests. Beware of the (im)possibilities of the patient (visual
impairment or paresis of dominant hand); which tests? Some tests are more reliable
and valid than others.
• Validity = does the test measure what it is supposed to measure.
• Reliability = do the scores represent actual functioning or is the measure error
too big? Especially important when testing multiple times with the same test!
• Norms (age, sex, level of education)
• In the NL the information on these quality specifics is checked by the
COTAN.
• Repeated testing → In theory, if a score the 2nd time of testing is outside the
confidence interval of the 1st testing; it implies significant difference between
the 2 scores. However, reliability (test – retest) information is often scarce.
Thus, it is often impossible to draw firm conclusion as people who have
multiple testing can learn (practice effect)
• Building the test battery → the test battery should be as short as possible to
not distress the patient more than needed, yet it has to answer the research
question and test the hypothesis.
i. Building the test battery: Fixed battery or flexible (individualized)?
1. Pro's fixed: the standardization means that the whole battery
together has been validated and has norms / easier to compare
, to other patients. - in flexible you don't know what the effects
of the one test on the other are. And simpler: you know what
and when to do.
2. Con's fixed: can you test all your hypotheses, and not do too
much?
ii. Order of the tests. Beware of the following:
1. Interference effects (no verbal learning tests in between
immediate recall and delayed recall of other verbal learning
tests)
2. Some tests use the same pictures
3. Practice effects (thus, spread tests that the measure the same
thing over different time periods)
4. Fatigue (demanding attention tasks schedules when patients are
still “fresh”)
5. Motivation and anxiety (start with relatively easy tasks,
except for those “high functioning patients who want to be
challenged”)
d) Differential diagnosis: symptom ≠ syndrome.
• The Halo effect = when you already believe in your head for something to be
true, and you just collect the evidence to support the idea. → Keep an open
i. mind that it could be all sorts of things, therefore we do the differential
diagnosis.
e) Importance of standardization (also of task instructions, test environment) → stick to
the same script of introducing the instructions! Try to create as clean of an
environment as possible without distractions!
- Observations during testing:
• Physical appearance → is the person able to take care of themselves, are they
groomed, do they smell, do they look age appropriate …
• Contact / rapport → are they cooperative, are they timid, eye contact…
• Understanding of the situation they are in
• Emotional reactions
• Attitude and executive functions
• Sensory functions
• Motor functioning
• Attention & concentration
• Speech & language
• Memory
- Outside of standardization
a) Testing the limits
a. When a patient cannot perform the tests – many reasons as to why may play a
role → You want to figure this out. So it’s important to see what a patient is
able to do (without time pressure), to see if they are able to handle it so it’s
just slow information processing, if they need social reassurance…
b) Disturbing factors may be related to external factors or to the patient
a. Sensory or motor handicaps, being of other ethnical background, depression,
fatigue, pain, anxiety, personality, light aphasia, legal issues (intentionally
underperforming on the tests), substance abuse/withdrawal issues, personality,
insufficient effort/lack of motivation.
