Chapter 2 - Higher congitive function
Questions
Define the following terms:
agnosia,
agnosagnosia,
apraxia,
receptive
aphasia,
expressive
aphasia,
global
aphasia,
alexia,
agraphia,
dysinhibition,
dysnomia,
paraphasic,
paratonia,
perseveration.
Agnosia is the inability to recognize what something is despite being
able to perceive it. This can be visual, auditory or tactile.
Agnosagnosia is the inability to recognize a particular deficit (for
example that one is paralyzed).
Apraxia is the inability to synthesize a complex motor pattern despite
having the strength and coordination to perform it.
Receptive aphasia is the inability to understand language (written or
verbal).
Expressive aphasia is the inability to synthesize language (written or
verbal).
Global aphasia is the inability to either understand or to synthesize
language (written or verbal).
Alexia is the inability to read.
Agraphia is the inability to write.
Dysinhibition is the appearance of responses that are normally
suppressed. In the context of higher cognitive functions, it is the
return of more primitive reflexes or behavior patterns that are
normally suppressed by "higher areas" of the brain (often the frontal
lobe).
Dysnomia is the inability to name objects.
Paraphasic errors include substituting words that have inappropriate
meaning, although the words sound somewhat similar or start with the
same sounds. This often happens with receptive aphasias.
Paratonia is an involuntary, irregular resistance to passive movement
(it feels like the patient is assisting in movement when they are not
attempting to).
Perseveration is repeating motions (or responses) when it is
inappropriate to do so.
2-1. Name some
cerebral cortical functions that are well localized and unilateral.
Answer 2-1. Well localized, unilateral cortical functions include:
somatic sensation, voluntary motor function (especially of hands), expressive
language, receptive language, attention to the contralateral world (neglect),
understanding of what is wrong (agnosagnosia), vision.
2-2. Name some
cerebral cortical functions that are well localized and represented bilaterally.
Answer 2-2. Well-localized and bilateral cortical functions: hearing,
short term memory, frontal lobe functions (mood, behavior, emotional
control, motivation, executive functions), visuospatial function
(parietal lobe)
2-3. Name some
cerebral cortical functions that are diffusely represented in the cerebral
cortex.
Answer 2-3. Diffuse cerebral cortical functions: long term memory, self
and species preservation functions (including many behavioral functions.
2-4. Damage to
which cerebral cortex produces aphasia?
Answer 2-4. Aphasia is lateralized to the dominant hemisphere
2-5. What can you
say about the ability to write in patients with aphasia?
Answer 2-5. Patients with aphasia will write and read the same way that
they speak and comprehend speech, respectively.
2-6. What can you
say about the ability of a patient with expressive, receptive, or global aphasia
to repeat complex phrases?
Answer 2-6. Patients with expressive, receptive or global aphasia will
be unable to repeat complex phrases.
2-7. What can you
say about the ability of a patient with transcortical aphasia to repeat complex
phrases?
Answer 2-7. Patients with transcortical aphasia will be able to repeat
although they may not be able to name objects that are presented to
them or to understand language.
2-8. What problems
will a patient with a transcortical aphasia have?
Answer 2-8. Transcortical aphasia: will be able to repeat complex
phrases but will either be unable to understand complex statements or
commands (transcortical receptive) or be unable to come up with names
for objects (transcortical motor).
2-9. What are the
characteristics of the patient with an expressive aphasia (Broca's)?
Answer 2-9. Epressive aphasia: Broca's area, nonfluent, frustrated,
dysnomic, can read and understand speech, telegraphic speech.
2-10. What are
the characteristics of the patient with a receptive aphasia (Wernicke's)?
Answer 2-10. Receptive aphasia: Wernicke's area, fluent, not
frustrated, dysnomic, can't read or understand complex speech.
2-11. What is
the most common lesion to produce alexia without agraphia (can write but can't
read)?
Answer 2-11. Damage to the dominant occipital lobe and splenium of
corpus callosum can produce alexia without agraphia (can write but
can't read).
2-12. What area
is involved in immediate recall (for example of a phone number)?
Answer 2-12. Immediate recall is a frontal lobe effect (give back a
phone number).
2-13. What area
is involved in short-term memory?
Answer 2-13. Short-term memory is a hippocampal function (minutes to hours).
2-14. Where is
long-term memory stored?
Answer 2-14. Long-term memory is stored diffusely (only lost if large
and diffuse areas are damaged).
2-15. What are
"executive functions" and where are they primarily located?
Answer 2-15. Executive functions in dorsolateral prefronal part of
frontal lobes - these include sequencing, planning, immediate recall,
abstractions.
2-16. Where are
the areas involved in most of emotional control and "personality"?
Answer 2-16. The orbital and medial frontal (and anterior cingulate)
cortex are involved in emotional control.
2-17. Damage to
which hemisphere is more likely to produce depression? Which will more likely
produce mania?
Answer 2-17. Left frontal damage often produces depression; right
frontal may lead to mania.
2-18. Neglect
of one side of the world is most commonly due to damage to what area?
Answer 2-18. The parietal lobe is responsible for attention to
contralateral world (damage produces neglect) and knowledge of deficits.
2-19. Agnosagnosia
most often results from damage to what area?
Answer 2-19. Agnosagnosia, a lack of recognition of problems, is due to
damage to the parietal lobe (especially the non-dominant side).
2-20. What "primitive
responses" would be expected to be uncovered by damage to the frontal lobes?
Answer 2-20. disinhibited glabellar, snout, suck, palmomental and
grasp reflexes.
2-21. Paratonia
is a sign of what?
Answer 2-21. Paratonia results from diffuse cortical dysfunction (some
degree may be normal).
2-22. What would
you expect to see in the patient with a split corpus callosum?
Answer 2-22. Corpus callosum lesions may prevent information from
transferring from one hemisphere to the other. The "left hand does not
know what right hand is doing."
2-23. The neocortex
provides inhibitory modulation of what four basic drives?
Answer 2-23. Feeding, fighting, fleeing and procreation (the four F's).
2-24. What is
the clinical term used to describe diffuse hemispheric disease (one word)?
Answer 2-24. Dementia.
2-25. What are
the clinical signs of advanced dementia?
Answer 2-25. Loss of cognitive, intellectual functions in more than one
sphere of function.
2-26. What regressive
reflexes emerge with loss of cortical inhibition?
Answer 2-26. Dysinhibition of glabellar response, palmomental reflex,
grasp reflex, suck reflex, rooting reflex, snout reflex and loss of
nuchocephalic reflex.
2-27. What
are the functions of the limbic areas of the brain?
Answer 2-27. Self and species preservation functions, the "four
F's" and emotional reactivity.
2-28. Of 100 people,
how many will have significant R hemispheric representation of speech functions?
Of these, how many will have bilateral speech representation?
Answer 2-28. 1% right dominant and 2% mixed.
2-29. What percentage
of R-handed people are L-hemisphere dominant for speech?
Answer 2-29. About 99.9%.
2-30. What percentage
of L-handed people are L-hemisphere dominant for speech?
Answer 2-30. About 70%.
2-31. Below what
age can speech function be recovered if the dominant hemisphere is damaged?
Answer 2-31. Age four.
2-32. What are
dysfunctions of speech called? What is a complete loss of speech called?
Answer 2-32. Dysphonia (if hoarseness due to mechanical problems in
larynx), dysarthria (if due to problems with cranial nerves or
cerebellum) or aphasia (this is actually a language problem, not just
speech problem). Dysphasia is incomplete, aphasia complete loss of
language function.
2-33. A patient
with verbal language dysfunction, homonymous hemianopsia, right visual field deficit
and little motor deficit most likely has what type of dysphasia?
Answer 2-33. Receptive (Wernicke's) - this is because Wernicke's area
is closer to the parietal lobe (and the optic radiations).
2-34. A patient
with verbal language dysfunction, marked hemimotor and hemisensory deficit,
and no visual abnormality most likely has what type of dysphasia?
Answer 2-34. Expressive (Broca's) - this is because Broca's area is
closer to the motor cortex.
2-35. Where is
Broca's area located? Where is Wernicke's area located? Name the fasciculus
that links the two of them.
Answer 2-35. Broca's - Inferior frontal lobe, just anterior to motor
cortex and near Sylvian fissure; Wernicke's - posterior part of
superior temporal gyrus; the arcuate (superior longitudinal) fasciculus
connects these language areas.
2-36. What gyrus
is important in language, especially in word retrieval?
Answer 2-36. Angular gyrus.
2-37. Do most
patients with dysphasia have Broca's, Wernicke's, or a combination of both?
Why is this so?
Answer 2-37. Combination because they are in same vascular distribution
on same side.
2-38. What language
abnormalities are manifested with a lesion to Broca's area? Wernicke's area?
Angular gyrus? Arcuate (superior longitudinal) fasciculus?
Answer 2-38. Broca's - expressive aphasia; Wernicke's - conductive
aphasia; Angular - dysnomic aphasia; Arcuate fasciculus - conductive
aphasia.
2-39. What part
of the corpus callosum transfers COMPLEX [i.e., verbal] visual info between
the two hemispheres?
Answer 2-39. The splenium.
2-40. What are
the predominant functions of the R cerebral hemisphere?
Answer 2-40. Visuospatial functions, attention to contralateral world,
musicality.
2-41. Which patient
will be more motivated to recover from a hemispheric lesion, one with damage
on the L or the R?
Answer 2-41. The left (the right hemisphere lesion can result in a lack
of appreciation for deficits and therefore problems in compensating).
2-42. Where is
the location of a lesion that causes visuospatial disorientation? How does
this manifest itself?
Answer 2-42. Right parietal lobe. Patients may get lost and have
trouble assembling things or figuring out how to make them work.
2-43. What type
of lesion will result in the loss of the ability to imprint new information?
Answer 2-43. Hippocampal lesions - medial temporal lobe (bilaterally).
2-44. Can well-learned
material be easily destroyed by a focal lesion? Why or why not?
Answer 2-44. No, there is diffuse representation.
2-45. What three
categories of questions need to be asked when testing a patient for problems
with learning and memory?
Answer 2-45. Immediate recall; short term recall (several minutes after
distraction); recall of remote events.
2-46. What evidence
would lead to the conclusions that a demented patient has disease localized
primarily in the frontal lobes (i.e., what are the manifestations of lesions
to the frontal lobes)?
Answer 2-46. Emotional lability, personality change
and/or loss of executive functions.
2-47. What is
the effect of lesions localized to the medial aspect of the frontal lobes
(parasagittal frontal cortex - supplementary motor area)?
Answer 2-47. Inability to initiate movements (abulia).