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Chapter 4

Case Study

Central Pain Syndrome

I was 42 years old when my life changed forever. I had a
stroke. As an avid viewer of medical programs on television I
assumed that I would have physical therapy for my paralyzed left
side and get on with my life. No one ever mentioned pain or the
possibility of pain, as a result of the stroke. I did experience
unusual sensitivity to touch while still in the hospital, but nothing
to prepare me for what was to come.

The part of my brain that is damaged is the Thalamus. This Image of the brain showing the location of
turns out to be the pain center and what I have now is an out of the hypothalamus.
control Thalamus, resulting in Thalamic Pain syndrome, also
called Central Pain Syndrome. This means that 24 hours a day, seven days a week, my brain sends
messages of pain and it never goes away. I am under the care of physicians, who not only understand
chronic pain, but are also willing to treat it with whatever medications offer some help. None of the
medications, not even narcotic medications, take the pain away. They just allow me to manage it so I
can function.

Hypothalamus
The Hypothalamus is a small part of the brain located just below the thalamus on both sides of
the third ventricle. Lesions of the hypothalamus interfere with several vegetative functions and
some so called motivated behaviors like sexuality, combativeness, and hunger. The hypothalamus
also plays a role in emotion. Specifically, the lateral parts seem to be involved with pleasure and
rage, while the medial part is linked to aversion, displeasure, and a tendency to uncontrollable
and loud laughing. However, in general the hypothalamus has more to do with the expression of
emotions. When the physical symptoms of emotion appear, the threat they pose returns, via the
hypothalamus, to the limbic centers and then the prefrontal nuclei, increasing anxiety.

The Fornix and Parahippocampal
These small structures are important connecting pathways for the limbic system.

The Cingulate Gyrus
The Cingulate Gyrus is located in the medial side of the brain between the cingulated sulcus and
the corpus callosum. There is still much to be learned about this gyrus, but it is already known
that its frontal part coordinates smells and sights, with pleasant memories of previous emotions.
The region participates in the emotional reaction to pain and in the regulation of aggressive
behavior.

Memory and Learning

Memory is defined as : The mental faculty of retaining and recalling past experiences, the act or
instance of remembering recollection. Learning takes place when we retain and utilize past memories.

There are three basic types of memory:

62 | Human Physiology