Lectures Medical Neuroscience and
Neuroanatomy
, Inhoud
Lecture 1 .............................................................................................................................. 3
Part 1: Introduction in neuroanatomy – Major subdivisions of the nervous system ............................................. 3
Lecture 2 .............................................................................................................................10
Part 1: Continuation of the introduction in neuroanatomy ................................................................................. 10
Part 2: Cerebral blood flow ................................................................................................................................ 14
Lecture 3 .............................................................................................................................20
Part 1: Lateral motor systems ........................................................................................................................... 20
Part 2: Medial motor systems ............................................................................................................................ 23
Part 3: Guest lecture about synaptic transmission ............................................................................................ 26
Lecture 4 .............................................................................................................................27
Part 1: Somatosensory pathways ...................................................................................................................... 27
Lecture 5 .............................................................................................................................33
Part 1: Cranial nerves........................................................................................................................................ 33
Part 2: Sleep ..................................................................................................................................................... 38
Part 3: Consciousness ...................................................................................................................................... 43
Lecture 6 .............................................................................................................................46
Part 1: Cranial nerves........................................................................................................................................ 46
Part 2: Guest lecture about electromyography .................................................................................................. 53
Lecture 7 .............................................................................................................................56
Part 1: Cranial nerves........................................................................................................................................ 56
Part 2: Visual system......................................................................................................................................... 58
Part 3: Autonomic nervous system .................................................................................................................... 61
Part 4: Hypothalamus ........................................................................................................................................ 68
Lecture 8 .............................................................................................................................72
Part 1: Limbic system – Hippocampus .............................................................................................................. 72
Part 2: Limbic system – Amygdala .................................................................................................................... 78
Part 3: Cerebellum ............................................................................................................................................ 80
Lecture 9 .............................................................................................................................89
Part 1: Brain tumors .......................................................................................................................................... 89
Part 2: Macroscopic dissection of the brain ....................................................................................................... 96
Part 3: Basal ganglia ....................................................................................................................................... 102
Lecture 10 .........................................................................................................................107
Part 1: Basal ganglia ....................................................................................................................................... 107
Part 2: Neurosurgery in epilepsy ..................................................................................................................... 110
Part 3: Cerebrospinal fluid disorders ............................................................................................................... 119
Lecture 12 .........................................................................................................................123
Part 1: Neuro-imaging ..................................................................................................................................... 123
Part 2: Midterm + questions + clinical cases ................................................................................................... 124
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,Lecture 1
Friday 09-09-2022
Part 1: Introduction in neuroanatomy – Major subdivisions of the nervous system
When you see a glance on top of the brain, then this is because of the pia mater, which is
one of the meninges. When you remove the outer layer of the brain, and then look at the
brain regions/cortex, then you can see the gyri and sulci.
The white color comes from the myeline (white matter). The function of myeline is signal
transmission. The higher the quality of the myeline, the higher the speed of the signal
transmission. Up until 25/30 years of age you are still developing the myeline. The higher the
cognitive reserve is, the more you are protected later against neurodegenerative diseases,
such as AD.
The myeline is interrupted by the nodes of Ranvier, which you need because the signal
jumps from one node to another.
Here you see the maturation of 4 tracks out of 18.
The first 12 years are important for the growth of the
white matter (myelination), and after that you see a
plateau. There is a reorganization of the central
nervous system, which means that a number of issues
will go down, like the gray matter, the volume will
decrease and there will be more space for the white
matter. This reorganization is a very critical period, at
this age you are extra vulnerable for psychiatry, like
eating disorders, depression, anxiety, etc. From that age on you see
an increase of the volume of the white matter.
After 30 years of age, what happens with the quality of the
myeline/white matter? This decreases. Each line in the picture
represents a lobe, the red line is the frontal lobe. The decline has a
number of severe consequences. The brain is not helping you to
remain challenged. What are the people doing that remain leveled at
that age, so the dots that are above the line?
- New things that are challenging
- Mental effort (in combination with physical effort)
Why is the white matter vulnerable for ageing? If you close one blood vessel, then the grey
matter will be damaged. You need vascularization and your heart to be active during the day
and to activate this system. When you sit all day, then the cerebral blood flow will decrease.
The superior longitudinal fascicle (SLF) has
three different pathways. These tracks are
associated with exercise and with cognition.
The upper part, so the dorsal SLF, is involved
in motor control, so exercise and movement,
but also in visual-spatial attentional network, this is what you need for mathematics, but also
language. So it is involved in both motor control and cognition. The ventral SLF is involved in
motor control, attentional and social cognitive network, and language: auditory
comprehensive articulatory processing. These functions won’t be asked on the exam!
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, Pure hemiparesis means no sensory loss, but only motor problems. You see here a
hemiparesis on one side of the body. A hemiparesis means a weakness of the muscles at
one side of the body. You could also say a hemiparalysis. What is the difference between
hemiparesis and hemiparalysis? Paralysis means a complete loss of function, and paresis
means that there is still some function possible. But these two terms are often misused.
Where do you expect the lesion to be? In the central or in the peripheral nervous system?
This is what you need to be able to answer at the end of the course.
You see here a pyramidal decussation, which
means that there is a crossing over of the
pyramidal tract, which is the cortical spinal. This
means that it is going from the cortex to the spinal
court.
Where is the origin of the corticospinal
tract/pyramidal tract? Posterior or anterior? It is
indeed more anterior. What function has the
parietal lobe when it comes to motor function?
Somatosensory information. If you look at the
corticospinal tract, it will descent. But before you initiate a movement, then there are a few
motor ‘loops’, for instance in the basal ganglia. Are the basal ganglia subcortical or cortical
regions? Subcortical. Also the thalamus is involved in this process, this is also subcortical. If
you look at the pons and the brain stem, then this is also subcortical.
Executive functions: planning, inhibition, working memory, etc. These functions are higher
order cognitive functions. Which subcortical areas are involved in executive functions?
Thalamus. Which cortical areas are involved in executive functions? Hippocampus. The
hippocampus is located at the medial-temporal lobe. The hippocampus is associated with
episodic memory, but also motor functions. An explanation of what makes the executive
functions a cortical-subcortical function is the fronto-striatal pathway. The striatum is the
combination of caudate nucleus and putamen (basal ganglia) and they have a strong
connection with the prefrontal cortex. So the fronto-striatal pathway is an example of a
cortical-subcortical combination for higher order cognitive functioning.
Which neurodegenerative disease comes to mind when we talk about the basal ganglia?
Parkinson’s disease. Would you expect a vulnerability in executive functioning in Parkinson’s
disease? Yes. They don’t have a decline here, but they are more vulnerable for it.
Could it be a peripheral nervous system problem?
No, because then all the peripheral nerves should
be affected. Then what is left is a central nervous
system lesion. So it is a central nervous system with
a pure hemiparesis.
If it is a cortical lesion, then you would also expect
problems in the sensory functions. The fact that the
upper part of the face is not affected, but the lower
part is affected. This means that the cortical part is
still intact.
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