What is the Difference between Peripheral Neuropathy and Complex
Regional Pain Syndrome?
By Elliot T. Udell, DPM
In podiatry, when we talk about peripheral neuropathy we
generally are referring to conditions that affect the local
nerves in the lower extremity. This is distinct from conditions
that affect the brain and/or spinal cord Diabetes is one of
the leading causes of peripheral neuropathy. Research shows
that diabetes affects the tiny nerves and small arteries in
the area where the patient is experiencing pain. The pain
is generally described as "severe burning" or "pins
and needles" and is generally worse at night. Months
or years later, this pain may lead to numbness indicating
the presence of far greater nerve damage, and in such cases
we have to be concerned with the development of ulcerations.
Complex regional pain syndrome (CRPS) presents quite differently.
Because my practice is focused on patients with severe foot
and ankle pain syndromes, I treat people with both peripheral
neuropathy and CRPS. Hence, I am well aware of the overt
as well as subtle differences between these conditions.
People with CRPS generally present with a history of
an inciting injury, which may be a sprain, fracture or even
surgery (many elective surgical procedures can lead to CRPS).
They also present with severe pain, which is far more intense
than that experienced by people with peripheral neuropathy.
The pain is so severe at times that even air blowing on the
area can cause a person to wince in distress. People who have
CRPS can also present with other symptoms generally not
associated with peripheral neuropathy, such as sleep disturbances
and clinical depression. The depression results from the physiology
and anatomy of the sympathetic nervous system synapses rather
than purely from an emotional reaction to the pain. Moreover,
we commonly see skin problems associated with CRPS, such
as edema and small shiny plaques that are exquisitely painful.
Another significant difference is the tendency of non-treated
CRPS to progress to the opposite extremity and to the
upper limbs. A glance at the anatomy of the sympathetic nervous
system, which runs parallel up and down both sides of the
spinal cord with perpendicular crosses from right to left,
may explain why this illness can easily progress to other
parts of the body. Also, CRPS patients often have both
spasms of the muscle and progressive muscle weakness. Untreated,
this muscle weakness can lead to atrophy and loss of use of
the extremity. Such extensive and debilitating muscle weakness,
as well as atrophy, is not common in peripheral neuropathy.
Because the anatomy and physiology of the symptoms are different,
so are the treatments of these conditions. The treatment of
CRPS is complex; we use intense physical medical modalities
and many different types of oral pain medications and antidepressants.
Each condition is different, challenging, and time consuming,
but the rewards of seeing patients leave their wheel chairs
and crutches and return to work and school makes any effort
we put into working with these people emotionally rewarding.
Dr. Elliot Udell specializes in pain management of the foot
and ankle. He is in practice in Hicksville, New York. He is
currently president of the American Society of Podiatric Medicine
and is on the board of the American Society of Podiatric Dermatology.
He is board certified in Podiatric Primary Care as well as
Pain Management. He lectures at medical seminars throughout
the US as well as in Europe.
Updated October 15, 2005