Brain Damage Exam 10-2013
1. The development of Neuropsychology
Learning goals:
- What are the different paradigms in the history of neuropsychology?
- What did phrenology teach us?
- What is visual form agnosia?
- What causes visual form agnosia?
- How can you examine visual form agnosia?
[Kolb & Wishaw Ch. 1]
Cardiac/brain hypothesis
- Mentalism -> There’s a nonmaterial psyche independent of the body (Aristotle). The mind is
responsible for our behavior.
- Dualism -> Mind and body work separately, but interact (Descartes). Mind body problem: how does
an immaterial mind influence a material body?
- Monism -> mind and body are a unitary whole
- Materialism -> The nervous system causes rational behavior (Darwin). The mind is all functions of
the brain together.
Localization theories
- Phrenology -> relation brain function and skull surface (Gall & Spurzheim). Bumps on the skull mean
greater capacity for certain function.
Phrenology was the foundation for modern localization theories. The naming of cortical lobes after
the overlying skull is still used. The phrenology map is the precursor of subsequent maps of the brain.
- Specialized localization -> Speech in frontal lobes (Bouillaud), lateralization of speech (Broca) and
connection pathways between areas (Wernicke). Areas of the brain are interdependent,
disconnection can cause apraxia and alexia etc.
- Hierarchical organization -> recovery of animals after removing parts of the brain (Flourens). After
removing the cortices animals recovered (Goltz). The brain has higher and lower functions and each
part had a special attribution. Binding problem: how can multiple parallel channels lead to a unified
representation?
- Imaging techniques -> Golgi found a method to study neurons. Cajal found that there are
specialized neurons in some areas. Fritsch discovered the electrical basis of the brain. Sherrington
found that there are synapses. Loewie discovered that there are chemicals to communicate
(neurotransmitters). Non-invasive techniques were made to measure brain activity.
- Statistics -> With Galton the psychometric testing began, the normal curve from Quetelet was
applied. Binet developed the IQ test, quantitative predictions were possible
Visual form agnosia
-> not able to see shapes, recognize objects
-> able to draw from memory, reach for an object.
Patient appears to be able to see when action is required, but blind to the form of an object.
<= occipital damage: visual cortex. Primary visual cortex -> Association Visual cortex -> parietal,
temporal, frontal.
,Dorsal stream damaged: how -> unconscious
Ventral stream damaged: what -> conscious. Visual cortex -> temporal lobe. This is damaged in visual
form agnosia, because there is no conscious perception, but there are unconscious visual processes.
The patient can use visual form information to guide movements (dorsal), but can’t use visual
information to recognize the same object (ventral).
Test: Ask the patient to copy a drawing and afterwards draw from memory. Ask the patient to hold
an envelope in the right position looking at the mailbox and afterwards ask the patient just to post it.
MRI, look which regions are active while patient is recognizing objects.
Disorder Symptoms Brain area Tests Additional info
Visual form Not able to see Ventral stream: Copy drawing and draw When
agnosia shapes, recognize conscious from memory movement is
objects perception. Let patient hold an required patient
envelope in the position of is able to do it.
the mailbox and just post Able to draw
an envelope from memory
2. Measurement of cognitive domains
Learning goals:
- What are the main domains of cognitive functioning? Which tests are used and why?
- What does neuropsychological assessment look like?
- What can influence NP testing?
- What additional information do you need to interpret the results? (How to prevent bias)
[Weintraub]
Cognitive domains:
- Attention -> Continuous Performance Test: measures sustained attention (vigilance). A target is
repeatedly presented among a series of randomly assigned stimuli. Press button when the target is
there. You have to stay focused. Glasgow Coma Scale: measures wakefulness. Digit Span Test:
reproduce number of digits in the same order or reversed (normally 7).
- Motivation and mood -> Beck Depression Test: questionnaire about feelings of dysphoria.
- Naming -> Boston Naming Test: 60 drawings of objects, give the right name for each object.
- Calculation -> Arithmetic Subtest of the Wechsler Adult Intelligence Scale: mathematical word
problems presented orally with time restraints. BDAE: finger identification, finger naming and visual
finger matching.
- Comprehension -> Token Test: Manipulation of plastic pieces. “Put the small yellow circle on the big
red square”. Boston Diagnostic Aphasia Examination: auditory language. Easy ‘yes’ or ‘no’ questions.
“Do dogs fly?”
- Construction -> Facial recognition test: select from 6 photo’s the 3 photo’s that represent the
individual on top. Discrimination essential facial features and recognition. Rey-Osterrieth Complex
Figure Test: copy a complex figure and later draw it from memory. Clock drawing: draw a clock.
- Reasoning -> Visual Verbal Test: divide the same set of items into two partially overlapping groups,
,wherein each group has a common attribute. The ability is to shift to another attribute, mental
flexibility. Wisconsin Card Sorting Test: mental flexibility. Alter response based on reinforcement.
Four stimulus cards with 1 of 4 geometric forms that differ in color and number. Match each test
card with one of the stimulus cards. Shifting in concepts. Matrix-type Reasoning task: choose the
design that completes the matrix, out of 8 choices.
- Visuoperception -> Judgement of line orientation: patient must select from a radial array of lines
those that match the angular orientation of the stimulus. Hooper visual organization test: 30 items
mentally assembling the fragments, identifying the object.
- Memory -> Wechsler Memory Scale II or Visual Verbal Learning Test: word lists presented over
several learning trials. An increase in words recalled is measured as learning. Visual reproduction
subtest WMSIII: non-verbal retrieval, reproduce geometric designs. Simple designs exposed briefly
for immediate and delayed reproduction.
- Planning -> Tower of London: a puzzle with planning and sequencing. The patient gets an apparatus
and a picture is shown of it. The patient has to move the beads , bead per bead, until it is the same as
the picture, in 4 steps. The Porteus Mazes Test: strategy to find a route in a maze. Taking some time
to examine the maze before initiating response.
- Language -> BDAE: naming pictures. WAIS: explanation of words, describe what they mean.
Influence on test results:
Age, gender, education, cultural and language background, medication, drug dependene, sensory
and motor status, intelligence, flexibility, mood, arousal, attention, motivation, executive functions.
[Kolb & Wishaw]
Attentional deficits => problems in almost every other area of cognition.
Distractability => interferes with leaning and cognitive performances.
Fatigue => cognitive impairment.
Pain => reduced attention, processing speed and psychomotor speed.
Motivation => perform below capacities.
Anxiety, stress and distress => mental efficiency problems.
Depression and frustration => interference motivation and related to fatigue.
Legal purposes => only tests that are scientifically defensible.
Prevent bias:
Prevent practice effects, order of tests important. Malingering, intentionally doing bad on the test
(to test malingering: TON, 50 pictures, which one they have seen before, <45 is malingering).
[Kolb & Wishaw] Background data, behavioral observation , test data, norms, sensitivity of a test
(correct positive).
[Kolb & Wishaw Ch. 28]
What does NP testing look like:
- History taking, diagnostic, source of condition and descriptive, behavior.
- Explanation about referral, plans about overall approach
- Prepatory interview: purpose, reason for examination, use of information, confidentiality, feedback
from patient, explanation of procedures and how does the patient feel?
- Observations, indirect (by others, nurse reports) direct (during examination and anamnesis).
- Test selection, validity, specificity and sensitivity
,- Basic Test Battery, major dimensions (drop some and choose new ones depending on patient)
- Hypothesis testing, data examination
- Selection additional tests
- Concluding the examination, answer diagnosis and descriptive questions or explanation why they
can’t be answered. Tip: end with easy task to give patient some sense of success.
- Interpretative interview, follow-up, patient understanding problems, relation with future,
recommendations. Briefly describing tests and examples of everyday functions that relate to it.
- Written reports, appropriate for circumstances
3. Traumatic Brain Injury (TBI)
Learning goals
- What is TBI?
- How do you determine how severe the damage is?
- What is coup-contre coup?
- What are the cognitive consequences of frontal lobe and parietal lobe damage?
- What is post-commotional syndrome?
- Explain the graph (with confidence intervals)
[Rohling]
Mild TBI has initially a small effect on neuropsychological functioning, but that dissipates quickly.
75% of the TBI is mild (mTBI).
Post-concussive syndrome -> dizziness, memory loss, headaches. Non-specific symptoms. Minority in
TBI patients continue to suffer from episodic memory loss, slow thinking, tiredness, irritability,
depression and changes in coping mechanisms: post-commotional syndrome.
Meta-analysis mTBI:
- Average loss of consciousness brief (10 min)
- posttraumatic amnesia relatively short
- Glasgow Coma Scale relatively high
mTBI is most sensitive to: verbal memory problems, working memory problems and visual memory
problems. Negative effects diminish over time.
There is a mild neuropsychological impairment after mTBI because of physiological changes on
cellular level, which are reversible. Initially there’s an impairment on verbal and visual memory.
Temporal lobe and orbitofrontal cortex vulnerable for mTBI effects.
[Frencham]
After 3 months post injury there is no significant reduction in cognitive functioning due to mTBI.
There is a cognitive impairment I working memory, attention and memory immediately after injury.
Tasks that are sensitive to TBI: speed of processing (Symbol Digit Modalities Test) , reaction time
tasks & recall (VVLT delayed recall).
[Kolb& Wishaw Ch.16]
Frontal lobes
Controlling behavior in response to social and environmental stimuli.
Lateral prefrontal cortex: multimodal areas, visual, auditory and somatic stimuli.
, Inferior ventral: olfaction and taste.
Control of movement:
- motor cortex
- premotor areas
- frontal eye fields
All receive projections from the dorsolateral prefrontal
cortex.
Prefrontal areas get input from dorsal and ventral streams. Orbitofrontal areas get input from all
sensory modalities. The orbitofrontal area sends input to amygdale and hypothalamus (autonomic
nervous system) . All neurons lead to the frontal lobe eventually.
Executive functions:
- Premotor cortex -> select movements (primarily external cues), movement sequences and
association with cues. Eye movements. Supplementary movement area: selection and direction
- Prefrontal cortex (PFC) -> making movements, controlling cognitive processes and selection at
correct time and place (internal- , external cues or self-knowledge). Short term memory. Autogenetic
awareness, self-knowledge as continuous through time.
LH: language related movements (speech), encoding information to memory
RH: Nonverbal movements (facial expressions), memory retrieval
! not as lateralized as parietal lobe.
Damage PFC => difficulties inhibiting behavior directed to external stimuli, because of lack of internal
stimuli (disctraction).
Orbitofrontal damage => association problems
Inferior frontal cortex damage=> problems with adaptation to social context
Frontal lobe damage
Symptom Examples Lesion site Test
Discturbances of motor Loss of fine movements - Hand
function Loss of strength Dorsolateral dynamometry
Poor movement Premotor, dorsolateral (strength), Finger
programming Frontal eye fields tapping (speed)
Poor voluntary eye gaze Premotor, dorsolateral
Poor corollary discharge
(stability world) Broca’s area
Broca’s aphasia
