A Case of the Week: Cassidy’s brachial plexus and radial nerve damage

November 24, 2012 by · 3 Comments 

cassidy brachial plexus radial nerve damageCassidy, a year old Australian Shepherd, was picked up by animal control and brought to the Humane Society of Jackson County, IN in late August. She had an injured left front leg that was swollen and dangling at the time. 3 veterinarians said it was nerve damage and only time would tell if the leg would regain use. Cassidy has brachial plexus and radial nerve damage sometimes called brachial plexus avulsion and is a common injury in dogs that are hit by cars.

In October she came to see me for treatment of the dangling leg since it was not seeming to be improving and in fact she was getting sores on the top of her foot. Her vet was considering amputation. Examining her it was obvious that she had suffered a severe injury to her brachial plexus and radial nerve and could not extend her leg as her triceps muscles and her digital extensor muscles were limp. She had also developed a common complication of this injury in that the opposing muscles the biceps and the carpal flexor muscles were contracted, since they have no opposing force to stretch them back out.

Most general practice veterinarians will give an anti-inflammatory (many times corticosteroid) and give the nerve time to heal and in many cases it does. If the brachial plexus or the radial nerve has been completely severed the dog will never regain use of its leg – the extensor muscles will remain flaccid and the flexor muscles will remain contracted. In cases in which the dog appears to not gain any movement back in the leg for an extend time such as in Cassidy’s case, most vets assume that the nerve is then severed and usually opt to amputate the limb; however some of these cases the brachial plexus/radial nerve just doesn’t heal with out stimulation. Neuromodulation is necessary to stimulate the nerve to regain function. It is sort of like you don’t use it so you lose it concept. Canine rehabilitation with neuro rehab is the treatment of choice for these dogs. The only problem, without trying to do electrodiagnostic testing, is that we will not know if it will work without doing the rehab and we have to try for 4-6 weeks without improvement to determine if it will not work.

In a case like Cassidy’s we have two goals – increase brachial plexus and radial nerve function and reduce flexor muscle contraction.

Therapies to reduce flexor muscle contraction –

  • Laser Therapy
  • Ultrasound Therapy
  • Manual Manipulation and Stretching
Therapies to increase brachial plexus and radial nerve function –
  • Acupuncture
  • Chiropractic
  • Laser Therapy
  • Electrostimulation
  • Manual Therapy and exercises to coax her to extend

Cassidy’s first visit we did laser therapy and chiropractic. Electrical acupuncture the next week. The third week we saw no improvement so we started electrical stimulation and laser therapy weekly along with exercises to entice her to extend her leg. The very next week we noticed movement in her triceps muscles! Some progress which meant that the brachial plexus was intact and eventually she would heal she just needed some stimulation.

There still was no movement even with electrical stimulation to the extensor muscles that controlled her carpus (wrist). What is very interesting is that if the nerve does not function electrical stimulation will not contract the muscle no matter how high of an electrical current you place into the muscle. If the nerve doesn’t work, the muscle does not work period. However repeated electrical stimulation will entice the nerve to function. I was a little discouraged that we had movement in the triceps but not the digital extensors I was starting to fear that the damage to the radial nerve was too great and we were not going to get that function back.

The very next week Cassidy came in still the same and although she was really extending her elbow. Although weak she was extending it during play, but the wrist remained contracted and unable to extend. We could straighten the wrist out about 80% of normal manually but there was no movement in the extensors, that is until we placed the electrical stimulator on her. We have movement with electrical stimulation to her toes! Way to go Cassidy!

We are going to continue electrical stimulation and exercises to entice her to extend her limb for the next few weeks. Hopefully in the next month or two she will be back to normal. Her brachial plexus and her radial nerve damage will be repaired and she will have normal function an start rebuilding the muscle she lost from the last 6 months.

About Dr Daniel Beatty
An Infopreneur with a Veterinary Medicine degree.