Point
6
Intro
Pathway
Deficits
Note
Problems
Contents
Anatomy
|
NOW FOR A DIFFICULT CONCEPT. There
are sympathetic-related fibers that arise from cells in the
hypothalamus and descend through the brainstem
to reach the spinal cord. In the spinal cord they travel in
the lateral funiculus in the most medial part of the LCST.
If these fibers are interrupted anywhere above T1, (in the
brainstem or between spinal levels C1 and T1) cells in the
lateral horn at spinal level T1 have lost their major drive.
The result is similar to a lesion in the lateral horn or
ventral root at T1. That is, the sympathetic outflow to the
head is interrupted, resulting in a Horner's syndrome. ALSO
SWEATING OVER THE REST OF THE BODY IS AFFECTED because cells
in the lateral horn, below T1, have lost their drive. So, a
lesion of the descending sympathetics above T1 = loss of
sweating over the entire body ipsi to the lesion. Lesion of
descending sympathetics below T1 spares the head and
involves loss of sweating below the level of the lesion.
|