Question: " I was told I have radiculopathy. What is this?"

Answer:

• The name is derived from Latin and Greek
• In Latin, radicula refers to root.  In medicine, radiculo- refers to a spinal nerve root.  
• In Greek, pathos refers to suffering. In medicine, -pathy at the end of a word is a general way of saying there is disease there.
• Therefore, radiculopathy is disease of the spinal nerve root. 

Background anatomy (Spine, Disc, Nerves):
I have some great anatomy pictures from my anatomy textbooks. However, I apparently have to get copyright permission to post the images. I’ll draw something if my description doesn’t do the trick.

-Spine (bone):

• In the lower back (lumbar spine) the five bones are labeled L1, L2, L3, L4, and L5.
• The “L” is short for Lumbar, and the following number is the vertebra (from top to bottom).
• The 5 bones stack up like toy wooden blocks.
• There is a disc between each vertebra (this is often the cause of the problems).
• The spinal nerves pass through a narrow apace between each vertebral body.  This space is known as the neural foramina.

-Anatomy (disc):

• There is a disc between each vertebra which acts like a shock absorber and allows for some movement. This disc space is a type of joint.
• The disc itself is looks a bit like a ¼ inch section of a tree branch. However, this cut branch of soft wood has a round sphere of jelly in the center.
• The outside of the disc, (the part with the wood-like looking rings), is called the annulus fibrosis.
• The central jelly part of a disc is called the nucleus pulposus.
• In total; the disk with two adjacent vertebral bodies is like a jelly donut between two blocks of bone (vertebra).

-Anatomy (Neurologic):

• The best way to think of the spinal cord is a bundle of electrical wires.  These wires connect your brain to the rest of your body and then and back again to your brain.
• The spinal cord carries many different types of wires in a space called the central canal.  The central canal is a tube in the middle of your back surrounded by bone.
• The wires that branch off the spinal cord are called a spinal nerves which innervate (connect to) both muscles and skin.
• A pair of spinal nerves branch off from the spinal cord and travels outward between each vertebra through the space known as the neural foramina. 
• The nerves are labeled in the same way the vertebral bodies are labeled; L1... through L5. 

-Anatomy (Neurologic more specific):

• Each pair of nerves has a specific job(s) and takes care of a specific area(s).
• When something happens to a specific spinal nerve, you will have symptoms/disability in the territory that that nerve innervates.  This can cause the symptoms of radiculopathy.
• Specific maps of spinal nerve-skin intervention are called dermatomes. For example, a map of the area that the L4 spinal nerve innervates is of an area of skin from the back to your leg and knee, down to your foot.
• Specific muscles are also controlled by spinal nerves and when injured there can be associated decreased leg strength and atrophy.

There are several causes of radiculopathy but most of them are either the result of an injured disc, bone (or both).

Disc causes:

• When a disc gets worn out many things can happen.
• Sometimes the disc will just bulge out like a beer belly.
• In another scenario, a tear forms in the annulus fibrosis.  This creates an opening for the jelly like center nucleus pulposus to squeezes out through the tear. Commonly this is called this a “ruptured disc.” This process is similar to jelly doughnut being squeezed with the jelly squirting out of one side. This jelly nucleus pulposus is thick and can squish whatever is in its way.
• If there is adequate room for the adjacent nerves, and if the rupture is small, then symptoms may be minor. However, when the disc material pins a spinal nerve or the spinal cord against bone, the symptoms can be severe.

Anatomic cause (bone):

• The spinal cord is protected from outside injury by the surrounding vertebra-bone.
• The nerve roots leave the central canal of the vertebra through openings called neural foramen.
• A possible outcome of the degenerative repair process is large bony callus formation which narrows the neural foramen and central canal. This is callus formation process is similar to a callus that may form on your foot in response to repetitive use. However, in the case of degenerative disc disease, the callus is made of bone.
• This bulky bony callus can get in the way and narrow the central canal and/or neural foramen.
• This callus generally grows relatively slowly and is not thought to be the cause of acute pain.
• However, a nerve within a critically narrowed space will be venerable to the presence of anything extra in that compromised area.  In this scenario, even the smallest disc bulge can completely narrow an already compromised opening.
• When the nerve gets pinched, you feel pain it in the area where that nerve was programmed to work.
• As discussed above, this can result in pain in a specific dermatome band and/or weakness of a muscle supplied by that nerve.

Diagnosis:

• Physical exam and symptoms often point to the problem.
• Anatomy and function are intimately related. The 3D imaging capability of MRI and CT can provide exquisite detail of the anatomic problem.
• As a result, imaging with MRI and CT can both confirm the cause of symptoms and quantify the extent of disease.  There is usually a direct correlation between the severity of the visible anatomic problem and symptoms. Imaging not only diagnoses the cause of symptoms, but also directs the type of treatment; the need for surgery or conservative therapy.