In this unit we will be studying disorders of the central
and peripheral nervous systems. The one over riding feature of pathology
of the nervous system, especially so for the brain, is the location of
the lesion. Time and again we will see that a perfectly benign tumor or
seemingly minor and seemingly inconsequential injury can be devastating,
if not lethal, when it occurs in a strategic location. Just as it is said
of real estate, the three most important facets of a property are its location,
its location and finally its location. The feature distinguishing central
nervous system from other systems we have studied is the fact that the
brain is a veritable prisoner within the fixed cranial vault. Edema of
the brain and mass lesions have no where to go. The pressure on surrounding
structures will prove most important. Still, as with every other
organ the nervous system suffer injury from all the major categories of
illness we have repeatedly visited.