Pinched Nerve Double Crush Syndrome

Pinched Nerve Double Crush Syndrome

Last year I saw a gentleman with complaints of pain and numbness in the neck, shoulder, arm and little and ring fingers of the hand. He was involved in professional motorcycle racing and had his share of accidents over the years. We had every reason in the world to think he was suffering from a pinched nerve in his neck.

Where was the pinched nerve located?

His MRI scan showed that he had a pinched C7 (cervical 7) nerve root at the C6-7 level of his cervical spine. It was pinched in the foraminal canal with a finding of severe foraminal stenosis (narrowing) at cervical 6-7. The foraminal canal is the short canal located at every level of the spine to allow passage of nerves out of the larger spinal canal. The nerves branch off the spinal cord and then pass through the foraminal canal before passing freely out to the arms and legs.

How was this pinched nerve freed up?

I don’t perform any fusions or disc replacements in my practice, so my treatment was to do endoscopic spine surgery to remove a small part of the facet joint (foraminotomy) that forms part of the foraminal canal. This requires that a small amount of bone be removed, but not enough to cause any instability. This is done through a 3/8” incision with minimal disturbance of the surrounding soft tissues. Once the nerve is decompressed (freed up), the symptoms of pain and numbness are expected to resolve, and they did resolve over the next several weeks except for one area.

What area still had symptoms?

Over the next several weeks, things progressed as expected with the exception that the little finger and a part of the ring finger remained numb with a little pain. This is the last area to regain sensation since it is the furthest away from the neck, but there just wasn’t any improvement. I like to be patient with the healing process and let the body heal itself, but I also like to set time limits on healing. In other words, if healing and improved symptoms don’t occur in a given time limit, then something else might be wrong.

Could the nerve be getting pinched somewhere else?

Yes, it can. The C7 nerve root passes out of the cervical spine (foraminal canal) and then joins with some other nerves to form the brachial plexus. Beyond the brachial plexus, the nerves are given names such as the median, radial and ulnar nerves. The nerves are just like electrical wires traveling throughout the body. In most instances, the route is very similar between different people. In the case of the little and ring fingers, they receive the nerve supply from the ulnar nerve. The ulnar nerve passes through a small bony tunnel on the inside of the elbow where it can get pinched.

How do we confirm a pinched nerve at the elbow?

As previously mentioned, an EMG with nerve conduction velocity was performed. This electrical test did show slowing of electrical impulses across the elbow that demonstrated that the ulnar nerve was getting pinched. An MRI scan was also done to confirm the dimensions of the bony tunnel – it was narrow. The diagnosis of Cubital Tunnel Syndrome of the elbow was now confirmed.
Is this an example of “Double Crush”?

Yes, it clearly is. The same nerve (C7 nerve root) going from the neck down to the little and ring finger was getting compressed in two separate locations. One was in the foraminal canal in the neck (C7) and the other was in the cubital tunnel on the inside of the elbow (ulnar nerve). This example of the same nerve getting pinched at two locations is referred to as “double crush” syndrome.

Unfortunately, it’s not usually possible to determine which area of compression is causing the most problem, so both areas have to be surgically decompressed. This is one example of double crush syndrome and there are several.

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