How to Diagnose Nerve Injuries Correctly
Our nerves need a healthy environment to work properly. This includes easy movement past the other tissues in the body, a good blood supply and lots of oxygen. Nerves don’t like to be compressed, stretched, irritated by inflammatory chemicals or lacking in blood and oxygen supply. With Carpal Tunnel Syndrome, the median nerve, which has to pass through a very small space at the wrist can easily become trapped and irritated. The blood supply can be compromised, leading to pain, a pins and needles feeling, numbness or weakness in the hands. Such symptoms are typical of nerve injury, but how are patients properly diagnosed to ensure the correct treatment options are offered? This is where tests such as the Tinel’s and Phalen’s tests are invaluable.
Irritated nerves do not respond well to vibration. Named after the French neurologist Jules Tinel, this test uses a vibration type pressure to aggravate nerve problems. The assessor will tap lightly but repeatedly at a fast pace over the nerve in question, and if the patient’s symptoms are reproduced into the hand or fingers, then the test can be deemed positive. Tinel’s test can be used to identify carpal tunnel syndrome, where the assessor will tap the median nerve at the wrist, or it can be used to identify other problems such as Guyon’s canal syndrome, which occurs when the ulnar nerve running down the forearm is compressed at the wrist.
George S. Phalen, the American hand surgeon, developed this test to diagnose carpal tunnel syndrome. The wrist is put into full flexion, where the palm of the hand is bent towards the arm, and held in this position for 1 minute. If symptoms are reproduced into the patient’s hand or fingers in this time then the test is deemed positive. This test works by making the carpal tunnel even smaller and so exacerbates nerve problems by further compressing the irritated nerve. This test can also be performed in full extension of the wrist (where the palm of the hand is bent away from the arm,) to achieve the same altered sensation and is referred to as the Reverse Phalen’s Test.
Both of these tests can be used confidently to assess nerve problems, but a physiotherapist would always use them as part of a complex clinical reasoning model to rule out other possible causes.
If a clear diagnosis of nerve injury or irritation has been reached, then treatment can commence and at intervals during your treatment, the Tinel’s and Phalen’s tests can be used again to review your progress. As nerve irritation can be slow to respond, these can be useful reassessment tools to identify improvement.
Are you concerned about a possible nerve injury? One of our experienced physios can come to you at home or work to solve what’s causing the pain and fix the problem. Don’t delay, contact us today!
Post by Leanne Plenge, Physiotherapist and Bristol Manager.