So we've covered a lot of content
in this lecture,
Let's do some quick review.
So one of the things I really was
trying to highlight was
distinguishing on physical
exam between upper motor neuron
it's the neuron that starts up here
in the cerebral cortex
and sends its axon
down the cortical spinal tracts
versus the lower motor neuron
with its nucleus in
the interior horn
that then goes out via nerve roots
and the peripheral nerves.
Both of them are going to have
So that's not going to be sufficient
to help to identify
what kind of problem there is,
though it will help you
to localize exactly
which muscle group is involved.
Muscle tone in upper motor
should be hypertonic
and potentially rigid.
Whereas, patients with lower motor
neuron disease will be flaccid.
I will just mention this here is
that someone with an acute stroke
will also be flaccid,
even though that is an
upper motor neuron problem,
the rigidity and the hypertonicity
can develop days to weeks later
should be found in those
with lower motor neuron problems.
And then deep tendon reflexes will
be hyperreflexic or hyporeflexic,
the type of neuron involved.
Which pairing is incorrect?
C6 and wrist flexors,
or is it C8 and the finger flexors?
C5 and the biceps reflex,
T1 and the interosseous muscles?
Or is it C7 and the triceps reflex?
So it's always challenging
to memorize these things,
but I really find that it's very
important to lock this content
into your memory.
So in this case, the answer is
C6 and the wrist flexors
because it's the sixth nerve root
that actually causes
is correctly paired.
All of the following are associated
with upper motor neuron
Clonus, Hoffman sign,
or the extensor plantar response,
or Lhermitte's sign.
Well, the only example on this list
that we would actually associate
with a lower motor neuron problem
and in particular,
radiculopathy would be spurling sign
also known as
the foraminal compression test,
which is looking for a
Everything else would be
findings that you may identify
with an upper motor neuron problem.