What is radiculopathy?
Radiculopathy can occur anywhere along the spine:
Neck / cervical spine = cervical radiculopathy
Mid back / thoracic spine = thoracic radiculopathy
Low back / lumbar spine = lumbar radiculopathy
Radiculopathy is a condition in which the nerve roots become damaged or pinched. At each level of the spine, between each vertebrae are small branches (nerve roots) that come off from the spinal cord.
For each level of the spine, there are two of these nerve roots on both the left and right side. The nerve roots at each level merge together to form a spinal nerve. There is a front (ventral) nerve root and a back (dorsal) nerve root - see image below.
Causes of radiculopathy
There are many causes for these nerve roots to become pinched or damaged, then leading to radiculopathy. The most common two are disc injuries and arthritis. See below:
Symptoms and signs of radiculopathy
Our spinal nerves transmit impulses to our muscles so that we can move them and to our skin for sensation. Therefore these are the aspects that are affected.
Radiculopathy presents with one or more of the following:
Please note: the above symptoms do not have to be caused by radiculopathy and they do not have to originate at the spine. There are many causes to any of the following symptoms and it is up to your clinician to determine the cause.
Sciatica
Formation of the sciatic nerve
There are two sciatic nerves; one for each leg. The nerve is the longest and widest single nerve in the body. It is formed by the joining together of 5 levels of nerve roots located in the low back and the sacrum/pelvis. The levels are L4, L5, S1, S2 & S3 (L for lumbar and S for sacrum).
These nerve roots eventually come together to form the sciatic nerve (i.e. a 'spinal nerve'). The nerve then runs through the buttock/gluteal region, down the back of the thigh to the knee. Then it separates into two nerves called the common peroneal and tibial nerves that run down the calf and into the foot.
What is the function of the sciatic nerve?
The sciatic nerve provides both motor (muscular control) & sensory supply (sensation of touch):
Motor:
Muscles of the back of the thigh (hamstrings) and a part of a muscle on the inside of the thigh called adductor magnus
Muscles in the calf and foot after it divides into the common peroneal and tibial nerves.
Sensory:
Outer aspect of the calf
The top and bottom surfaces of the foot and the heel
What is sciatica?
The terms sciatica and lumbar radiculopathy are often used interchangeably for simplicity sake.
Sciatica is radiculopathy specifically along the distribution of the sciatic nerve, i.e. one of more of the levels that form the sciatic nerve are affected (L4, L5, S1, S2, S3).
There are 5 levels in the lumbar spine, so lumbar radiculopathy that can present differently to sciatica, such as when levels L1, L2 or L3 are affected.
Sciatica symptoms
The location of symptoms for sciatica are anywhere along the trajectory of the nerve:
buttocks/gluteal region
hamstring/back of thigh
calf
foot
Symptoms of sciatica are the same as lumbar radiculopathy. They include one or more of the following as displayed in the image.
A qualified health professional such as an osteopath, physiotherapist, general practitoner, etc is trained to diagnose the cause of radiculopathy/sciatica.
Treatment of sciatica/lumbar radiculopathy
Treatment options for sciatica/lumbar radiculopathy depend on the cause.
The right diagnosis ensures appropriate management.
Summary
Radiculopathy involves nerve roots being affected anywhere along the spinal coloumn. There is cervical, thoracic and lumbar lumbar radiculopathy.
The symptoms & signs of radiculopathy are weakness, radicular pain, loss of sensation, numbness, tingling, muscle wasting & loss of reflexes.
Sciatica is the equivalent of lumbar radiculopathy but specifically along the sciatic nerve.
There are many causes of sciatica/lumbar radiculopathy. Have an appropriately qualified health practitioner make the diagnosis so that they can help you find a resolution.