PPP4010 Clinical Neuropsychology
1
LECTURE 3 FUNCTIONAL NEUROANATOMY 2
TODAY:
1.
SENSORY PATHWAYS AND THE “AGNOSIAS”
2.
MOTOR SYSTEMS
3.
VENTRICLES AND BLOOD SUPPLY
4.
LIMBIC SYSTEM
5.
THE NEUROLOGICAL EXAM
Required reading:
Chapters or sections on the “vasculature” of the brain and ventricles from any neuroanatomy textbook you fancy
Work through your chosen textbook and my slides on the basal ganglia and thalamus in particular---see if you can
figure them out in both horizontal and coronal sections!
Also bits on visual, auditory, somatosensory and olfactory pathways, and section on the corticospinal tract please
Dr David Carey
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DeYoe et al. (2011). fMRI of human visual pathways. in Functional Neuroradiology: Principles
and Clinical Applications, S. Faro and F.B. Mohamed, Editors. 2011, Springer: New York. p.
485-511.
3
Visual agnosia
failure to recognize objects using vision
relatively “intact” vision
cannot be explained by blindness, aphasia or
dementia, etc.
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5
Visual agnosia (Cont’d)
* Two types:
Apperceptive: problems with lower level perceptual processes (e.g. they can’t copy
drawings)
Associative: problems associating the relatively intact percept with stored information
about what the percept is (e.g. can copy, but can’t recognise what they copy!)
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Visual agnosia (Cont’d)
idea is that apperceptive agnosic patients have problems “nearer” to
perceptual processing, associatives have damage further along, “nearer”
to access to long-term representations of what objects look like
visual input------->------>------>---------> recognition
Sensation
Perception
“Memory”
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8
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Visual agnosia (Cont’d)
“The patient’s failure to recognise line drawings of common objects, however,
draws attention to the importance of the opposite principle, that recognition
depends upon abstraction, not only from the environment, but even from the
object itself.
We are so familiar from an early age with the representation of common objects by
outline drawings that we are apt to forget how abstract such symbols are.”
Brain (1941)
Who is this….??
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Prosopagnosia
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failure to recognize familiar faces
often accompanies visual agnosia but can occur in isolation
is it a “real” disorder, or are faces just an extremely difficult class of visual stimuli?
Sheep? Cows? Cars? Birds?
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Prosopagnosia
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“When Bodamer discovered the patient’s problem, he was able to establish that S. could tell
that certain objects were faces, but not to whom they belonged-indeed he was unable to
read facial expressions or even distinguish women from men, except by using hair or hat
cues. When confronted with his own face in a mirror, S. could not recognise it-nor even be
sure of its gender.”
Ellis (1996) on Bodamer (1947) in Classic Cases in Neuropsychology. C Code et
al. (Eds.), Psychology Press.
14
From: Kanwisher, N., & Yovel, G. (2006). The fusiform
face area: a cortical region specialized for the
perception of faces. Philosophical Transactions of
the Royal Society of London B: Biological Sciences,
361(1476), 2109-2128.
From: Bernstein, M., & Yovel, G. (2015). Two neural
pathways of face processing: a critical evaluation
of current models. Neuroscience & Biobehavioral
Reviews, 55,
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Farnsworth Munsell 100 Hue test
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Achromatopsia
Acquired deficit in identifying colours (but
sometimes can discriminate one from another)
"Colour anomia" can't name them
"Colour agnosia" can see that two colours are
different, but can’t match them very well
can occur in one visual field only!
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“‘On January 2nd of this year I was driving my car and was hit by a small truck on the
passenger side of my vehicle.
When visiting the emergency room of a local hospital, I was told I had a concussion. While
taking an eye examination, it was discovered that I was unable to distinguish letters or
colors. The letters appeared to be Greek letters. My vision was such that everything
appeared to me as viewing a black and white television screen.
Within days, I could distinguish letters and my vision became that of an eagle—I can see a
worm wriggling a block away. The sharpness of focus is incredible.
BUT—I AM ABSOLUTELY COLOR BLIND.
I have visited ophthalmologists who know nothing about this colorblind business. I have
visited neurologists, to no avail. Under hypnosis I still can't distinguish colors. I have been
involved in all kinds of tests. You name it. My brown dog is dark grey. Tomato juice is black.
Color TV is a hodge-podge”.
Sacks and Wasserman (1987)
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“‘You might think’, Mr. I. said, ‘loss of colour vision, what’s the big deal? Some of
my friends said this, my wife sometimes thought this, but to me at least it was
awful, disgusting.’
It was not just that colours were missing, but that what he did see had a distasteful,
‘dirty’ look, the whites glaring, yet discoloured and off-white, the blacks
cavernous-everything wrong, unnatural, stained and impure.”
Sacks and Wasserman (1987)
Some achromatopsics can see the borders between two colours if adjacent. BUT…. if they
are separated by a thin black line, can't tell if they are same or different!
Lesion usually includes the fusiform and lingual gyri in the occipto-temporal cortex
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Zeki, S. (1990). A century of cerebral achromatopsia. Brain, 113, 1721-1777
A
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Lesion overlaps with neuroimaging results. Achromatopsia and prosopagnosia lesion overlaps are shown with
representative neuroimaging peak activations superimposed. On achromatopsia lesion overlap (left), black symbols
indicate posterior color-sensitive findings and red symbols indicate anterior color-sensitive findings...
On prosopagnosia overlap (right), black symbols indicate responses near the face-sensitive area FFA, red symbols indicate
responses near the face-sensitive area OFA, and the purple symbol indicates a response near the face-sensitive area STS
Bouvier, S.E.& Engel, S.A. (2006). Behavioral deficits and cortical damage loci in cerebral
achromatopsia. Cerebral Cortex, 6, 183-191.
22
Of course, we also identify things using sound, touch, and taste…
Non-visual agnosias
Can you recognise things from other sensory modalities?
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Primary somatosensory cortex: anaesthesia
Primary auditory cortex: cortical “deafness” (?)
Primary visual cortex: cortical blindness
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25
Somatosensation – really a grab bag category of
senses that have to do with the body….pain, vibration,
temperature, cutaneous sensations (e.g. light touch,
movement, stretch of skin), proprioception (body
position), kinesthesis (body movement)
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Somatosensory pathways
From Carlson (2010)
Physiology of Behavior 10th ed. Allyn
and Bacon
Dorsal columns-medial lemniscus
pathway—fine touch, position sense
Spinothalamic pathway--pain,
temperature and crude touch
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Hoffman (1884) “stereognosis” – ability to recognise objects by touch
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Many different types of
somatosensory receptor (e.g.
mechanoreceptors under your skin,
muscle spindles that detect stretch
etc.)
Astereognosis – disturbances in the ability to recognise objects by touch (more or less
synonymous with “somatosensory agnosia”)
29
"Patient H.K., a 51-year-old man, attended medical care due to paraesthesias on the left
side of his body. Cranial computerized tomography and MRI revealed a right parietal
tumour. Craniotomy was performed a few days later for removal of the tumour, which was
histologically classified as meningeoma. His postoperative clinical and neurological status
was unchanged.
Four weeks postoperatively he was admitted to our department for functional neurological
evaluation and rehabilitation, since he subjectively reported deficits of fine motor control of
his left hand even though no overt paresis could be documented.
Platz, T. (1996). Tactile agnosia. Casuistic evidence and theoretical remarks on modality specific
meaning representations and sensorimotor integration. Brain, 119, 1565-1574.
Platz, T. (1996). Tactile agnosia. Casuistic evidence and theoretical remarks on modality specific
meaning representations and sensorimotor integration. Brain, 119, 1565-1574.
30
An MRI of the head was also done 10 months postoperatively and revealed
cortical damage of the right postcentral gyrus, but especially of the right supramarginal
gyrus (Fig. 1)
"Routine testing of sensibility revealed normal sensation of light touch, pinprick,
position sense and vibration throughout his body. Sensation of temperature
seemed to be slightly impaired for his left hand.
Without visual clues he recognized numbers written on his palm flawlessly on both
sides. However, he seemed unable to recognize common objects when they were
put in his left hand even though he could name these objects instantly when put in
his right hand afterwards".
31
Platz, T. (1996). Tactile agnosia. Casuistic evidence and theoretical remarks on modality specific
meaning representations and sensorimotor integration. Brain, 119, 1565-1574.
Auditory pathways
From Carlson (2010)
Physiology of Behavior 10th ed. Allyn
and Bacon
32
33
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Baumann, S., Petkov, C. I., & Griffiths, T. D. (2013). A unified framework for the organization of
the primate auditory cortex. Frontiers in Systems Neuroscience, 7, 11.
35
Auditory agnosias?
Reviewed 175 cases of auditory perceptual disorders from 1883-2001. Throws out a bunch…
"We were left with 45 cases of circumscribed vascular damage to one or both hemispheres with
sufficient evidence concerning both music and environmental sound recognition. Of these, 32 were
not dissociated: both music and environmental sounds were spared in 5 and impaired in 27. The
remaining 13 cases (28.9%) were dissociated.
Music was found to be selectively impaired in 11 cases and environmental sounds in 2…"
Vignolo (2003). Music agnosia and auditory agnosia: Dissociations in stroke patients.
Annals of the New York Academy of Sciences, 999, 50-57.
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Vignolo, LA (1982). Auditory agnosia. Phil. Trans. R. Soc. London B, 298, 49-57.
Auditory agnosias?
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NS, a 68-year-old left-handed man, had difficulty understanding speech after a stroke sustained
during coronary artery bypass surgery. When he awoke from anesthesia, he could not understand
what people were saying, as if they were “speaking too fast or in Chinese.” His own speech was not
affected, and he could read and write.
Twelve years after his stroke, the patient underwent further evaluation for his auditory disorder. On
interview, he was aware of his auditory difficulty and reported that speech still sounded fast and
foreign and environmental sounds muffled. He endorsed a greater appreciation of music and would
illustrate this by breaking out into song.
Mendez (2001). Generalized auditory agnosia with spared music recognition in a left hander.
Analysis of a case with a right temporal stroke. Cortex, 37, 139-150.
Auditory agnosias?
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Mendez (2001). Generalized auditory agnosia with spared music recognition in a left hander.
Analysis of a case with a right temporal stroke. Cortex, 37, 139-150.
Auditory agnosias?
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Mendez (2001). Generalized auditory agnosia with spared music recognition in a left hander.
Analysis of a case with a right temporal stroke. Cortex, 37, 139-150.
Perception
Auditory
input
Recognition
Acoustical analysis
Representations
“Apperceptive
agnosia”
“Associative
agnosia”
Auditory agnosia
is generally of this type
In visual agnosia some evidence for apperceptive and associative agnosia
Apperceptive agnosia – inability to form useable percepts, therefore poor recognition
Associative agnosia – inability to recognise the object but able to perceive its elements
etc to a reasonable degree
CORTICOSPINAL (PYRAMIDAL) TRACT
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Corticospinal tract – originates mainly
from primary motor cortex (but some
somatosensory and premotor neurons
contribute to it as well)
Pyramids – refer to a sort of hindbrain
“bulge” where many of the axons
cross over (“decussate”) to the other
side of the spinal cord
“upper motor neurons”
Dr David Carey
CORTICOSPINAL (PYRAMIDAL) TRACT
This anterior limb and posterior limb of the
internal capsule business is easy if you are
in a horizontal section
42
<-Still anterior limb here
<-posterior limb from just before
this section backwards
Dr David Carey
CORTICOSPINAL (PYRAMIDAL) TRACT
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Pyramids – refer to a sort of hindbrain
bulge where many of the axons cross
over to the other side of the spinal
cord
Dr David Carey
CORTICOSPINAL (PYRAMIDAL) TRACT
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From Netter.
Dr David Carey
CORTICOSPINAL (PYRAMIDAL) TRACT
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Some older books talk about the
“extrapyramidal motor system—
meaning all of the other circuits in the
brain that can eventually influence
spinal motor neurons.
Note that the basal ganglia aren’t
shown—they don’t talk much to the
spinal cord per se, but to motor bits of
the thalamus and to the premotor
and motor cortices
From Brodal, P. (1998). The central
nervous system: structure and function
(2nd ed.). Oxford: Oxford Univesity
Press.
Dr David Carey
CORTICOSPINAL (PYRAMIDAL) TRACT
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From Brodal, P. (1998). The central
nervous system: structure and function
(2nd ed.). Oxford: Oxford Univesity
Press.
Dr David Carey
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CORTICOSPINAL (PYRAMIDAL) TRACT
Hemiplegia/hemiparesis – paralysis or
weakness on the side off the body
contralateral to a lesion which effects
motor cortex and/or the corticospinal
tract—usually pariesis as the lower
motor neuron pool in the spinal cord
are undamaged
Axial (or proximal)muscles can
recover but distal muscles like hands
often do not….
Dr David Carey
THE VENTRICLES
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Netter, F.H. (2011) Atlas of Human Anatomy.
Philadelphia: Saunders. In electronic books
Interthalamic adhesion=massa intermedia
(thing that attaches two thalami across the
midline)
Dr David Carey
THE VENTRICLES
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From Brodal (2004).
Dr David Carey
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51
Vanderah, T., & Gould.
D. (2015). Nolte’s The
Human Brain: An
Introduction to its
Functional Anatomy.
Elsevier Health
Sciences.
52
Note the “concavity”
(laterally) in each
lateral ventricle:
caused by the head
of the caudate
nucleus! Does this
help you get the 3D a
bit?
…MOSTLY TEARS (THE VENTRICLES)
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Kiernan, J., & Rajakumar,
R. (2013). Barr's the human
nervous system: an
anatomical viewpoint.
Lippincott Williams &
Wilkins.
Dr David Carey
BLOOD SUPPLY
http://www.wisegeek.com/what-are-the-blood-vessels-of-the-brain.htm
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Dr David Carey
Posterior cerebral arteries
Basilar artery
Vertebral arteries
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Anterior communicating
artery
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Anterior cerebral arteries
Posterior communicating
arteries
Internal carotid/
middle cerebral arteries
Posterior cerebral arteries
Basilar artery
Vertebral arteries
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From Walsh, K. (1987).
Neuropsychology: a Clinical
approach. Singapore:
Longman.
59
Anterior cerebral artery strokes:
1. can effect superior regions of primary motor and
primary somatosensory cortex: weakness or
hemiplegia of contralateral side, often the lower limb.
2. Medial premotor cortex (e.g. supplementary motor
cortex, the SMA and pre-SMA)—bimanual
coordination, movement sequences??
https://radiopaedia.org/articles/anteri
or-cerebral-artery-aca-infarct
3. Anterior prefrontal cortex: dysexecutive symptoms
(more on this from OT in lecture 9 on the Frontal lobes)
Case courtesy of Dr Varun Babu,
Radiopaedia.org, rID: 46794
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62
From Walsh, K. (1987).
Neuropsychology: a Clinical
approach. Singapore:
Longman.
63
Middle cerebral artery strokes:
1. can effect large parts of the
lateral brain surface weakness
or hemipariesis of contralateral
side, often the whole body of just
head, neck, trunk and arm/hand
(legs spared); hemianesthesia of
contralateral side of the body;
dysphasias and dyspraxias after
left hemisphere lesions,
hemispatial neglect after right
lesions
Case courtesy of Dr Ian Bickle,
Radiopaedia.org, rID: 46842
2. Basal ganglia and the internal
capsule; face and upper arm
“upper neuron motor” weakness
From Kiernan, J.A.
(1998). Barr’s The
Human Nervous
System.
Lippincott-Raven
65
From Walsh, K. (1987).
Neuropsychology: a Clinical
approach. Singapore:
Longman.
66
67
From Walsh, K. (1987). Neuropsychology: a Clinical approach. Singapore: Longman.
Posterior cerebral artery strokes:
68
1. Occipital lobes : visual field deficits (should be
homonymous i.e. the same in both eyes), if V1
spared then occasionally agnosias (bilateral or
right hem)/alexia (lleft hem).
2. Splenium of the corpus callosum …confusion in
50% of cases, according to one source
https://radiopaedia.org/articles/posteriorcerebral-artery-pca-infarction
69
https://studentconsult.inkling.c
om/read/vanderah-nolteshuman-brain-7/videos/video-61
From Vanderah, T., & Gould.
D. (2015). Nolte’s The
Human Brain: An
Introduction to its Functional
Anatomy. Elsevier Health
Sciences.
71
THE LIMBIC SYSTEM
Heimer, L., & Van Hoesen, G.
W. (2006). The limbic lobe and
its output channels:
implications for emotional
functions and adaptive
behavior.Neuroscience &
Biobehavioral Reviews, 30(2),
126-147.
“Paul Broca considered the limbic lobe to be the fifth lobe of the brain. It is on the medial surface of
each hemisphere. It is actually a rim of cortex. This cortex is not convoluted and is phylogenetically
among the oldest structures of the brain. This circular area includes the septal region, hippocampal
gyrus, cingulate gyrus and island of Reil. The limbic system includes the olfactory bulb and tract,
hippocampus, fornix, amygdaloid body, and septal nuclei. The principal effectors of the limbic
system are the reticular formation and the hypothalamus. This "old brain," especially the amygdala is
quite involved in emotion. The hippocampus is involved in memory”.
www.csuchico.edu/~pmccaff/limbic.html
Dr David Carey
THE LIMBIC SYSTEM
Dr David Carey
THE LIMBIC SYSTEM
http://www.acbrown.com/neuro/Lectures/Lmbc/NrLmbcLmbc.htm
Dr David Carey
THE LIMBIC SYSTEM
http://www.acbrown.com/neuro/Lectures/Lmbc/NrLmbcLmbc.htm
Dr David Carey
THE LIMBIC SYSTEM
http://www.acbrown.com/
neuro/Lectures/Lmbc/NrLm
bcLmbc.htm
Dr David Carey
3D corpus callosum and fornix
http://www.univbrest.fr/S_Commun/Biblio/ANATOMIE/Web_anat/Snc/Cer
veau/Fornix.jpg
78
http://www.yalescientific.org/2
011/05/the-neural-basis-ofolfaction/
Disorders of smell
79
“Unless smell or taste is necessary for a particular hobby or profession (e.g. cooking or winetasting), most people treat these senses as being of much less importance than, for example,
vision and hearing. They are often taken for granted, and minor disturbances consequently go
unnoticed.
We neurologists undoubtedly neglect both smell and taste, as exemplifed by the standard
teaching that examination of the first cranial nerve just involves asking the patient whether or not
they have noticed any problem with their sense of smell.
Both smell and taste are usually not examined at all, as evidenced by the rather disgusting dried
out, crystal-encrusted smell and taste bottles which can often be found gathering dust at the
back of examination equipment cupboards on most neurology wards.”
Lueck (2003), Smell and taste complaints [book review]. Brain (2003)
126(5): 1244-1245 doi:10.1093/brain/awg097
80
From Carlson (2010)
Physiology of Behavior 10th ed. Allyn and Bacon
Disorders of smell
81
“Eichenbaum et al. (1983) found that H.M., a patient with bilateral medial temporal lobe
resection, exhibited impaired olfactory identification
(by matching to sample or naming) despite normal performance on tests of odour
detection [and] discrimination of odour intensity…”
Levin et al. (1985), Brain 108, 579-591
Fornix—connects
hippocampus to
mammillary bodies
(hypothalamus) and
anterior nucleus of
thalamus
Dr David Carey
3D corpus callosum and
fornix
http://www.univbrest.fr/S_Commun/Biblio/ANA
TOMIE/Web_anat/Snc/Cervea
u/Fornix.jpg
3D corpus callosum and
fornix
The Neurological examination
84
Mental status testing—(Mini mental status exam or more recently the “MOCA”—Montreal
Cognitive Assessment). More frequently “orientation” where are you? What is the date? How did
you get here? Why are you seeing me here?
Cranial Nerves (smell, visual acuity, pupil size and state, accommodation, eye alignment, eye
movements, saccades versus pursuit), facial sensation, jaw reflex, chewing, tongue movements,
say “ahhhh”, gag reflex….
Muscle strength, tone and bulk….
Reflexes
Coordination
Sensory Function
Gait
Dr David Carey
85
Next week: Neuropathology.
Required reading:
Goldstein and McNeil (2013) pgs 28-56. (most of the
chapter called Neuroanatomy and neuropathology).
Coetzer and Balchin (2014) chapt 3. Neuropathology.
Gurd et al. (2013). Chapt 26 Neuropsychology of vascular
disorders and Chapt 27 Neuropsychological presentation
and treatment of traumatic brain injury.