Degenerative Myelopathy (DM) is an incurable, chronic, progressive, neurologic disease that causes hind limb weakness and eventually leads to complete paralysis. Also known as chronic degenerative radiculomyelopathy, it is similar in many ways to amyotrophic lateral sclerosis (Lou Gehrig’s Disease). The exact cause is unknown but a hereditary predisposition has been identified. It is most common in German Shepherds and GS crosses but can be seen in other large breeds and Corgis. Also, DM usually affects older animals with the average onset age being 9 years.
DM causes degeneration of the white matter of the spinal cord. The white matter contains fibers that transmit movement commands from the brain to the limbs and sensory information from the limbs to the brain. Degeneration consists of both demyelination (stripping away the insulation of these fibers) and axonal loss (loss of the actual fibers) and interferes with the communication between the brain and limbs. DM initially affects the back legs and causes muscle weakness, muscle loss, and lack of coordination with progression over time to complete paralysis. As the disease progresses, the animal may display symptoms such as incontinence and has considerable difficulties with both balance and walking. If allowed to progress, the animal will show front limb involvement. Eventually, cranial nerve or respiratory muscle involvement necessitates euthanasia.
Historically, the average mean survival is only 8-10 months from the onset of clinical signs. There is no effective treatment. However, a study published in the Journal of Veterinary Internal Medicine in 2006 done by Kathmann, et al, showed that intensive physical therapy was able to extend the quality of life and preserve muscle strength. Underwater treadmill, range of motion, stretching, controlled standing routines, core exercises, and walking obstacles were all beneficial. At home therapy is just as critical to success, and affected dogs should be encouraged to be as active as possible.
A recent study published in Photobiomodulation, Photomedicine, and Laser Surgery, demonstrated that intensive laser therapy could significantly increase longevity and quality of life when done in conjunction with physical therapy. The study demonstrated that delivering a very high dose of therapeutic infrared laser energy to the thoracic and lumbar spine along with an intensive rehabilitation therapy regimen provided a significant beneficial effect for these patients almost doubling survival times in many patients. There are several proposed mechanisms of action related to how laser therapy slows disease progression. These would be related to the direct effects on the spinal cord and nerves as well as the benefits to the musculoskeletal system.
Photobiomodulation (PBM) will improve neurologic function by providing anti-inflammatory effects on the peripheral nerves and spinal cord. Laser therapy can slow axonal loss and demyelination. It has also been shown to improve axonal regrowth and nerve function. In addition, it is not uncommon for DM dogs to have other concurrent spinal cord or orthopedic conditions. The laser will have the same benefits in relieving pain and inflammation in the joints and the surrounding soft tissues. PBM can relieve muscle spasms, and trigger points as well as reduce adhesions, and help reverse muscle atrophy. PBM can help remodel the fibrosis in the joint capsule to aid the range of motion, issue a positive effect on the synovial lining, therefore, as well as the synovial fluid, supply a positive effect on the articular cartilage, and can reduce the inflammatory cytokines within the joint. All these aid in improving function, comfort, strength, and mobility- ultimately slowing the progression of DM.
Another key benefit is related to the need for an intensive rehab and physical therapy regimen. Not only has PBM been shown to enhance muscle function and performance, but it has shown the ability to reduce the rate of time of muscle fatigue by improving muscle energy metabolism. It has also been shown to mitigate muscle soreness related to intensive exercise. Studies show that laser therapy will reduce lactic acid and creatine kinase levels normally associated with strenuous activity. It can also speed recovery. Thus, aid the patient’s therapeutic exercise program.
Your Summus Medical Laser can easily be programmed to deliver this therapeutic treatment. The protocol is simple to produce and save in your current laser for use on any size patient using the following guidelines. Start by selecting a chronic back setting for a dark-coated animal and use the edit button to change the phase times and powers according to the following weight class for the patient(s) to be treated- the key is to aim for a dosage range of at least 14-21 J/cm2.
Weight (lbs) Phase Time(seconds) Average Power(W)
15-30 108 6.0
31-50 125 7.0
51-70 125 9.0
71-90 125 11
>90 133 12
You would treat 2 or 4 ‘Areas’ based on the diagnosis of structures involved. If there are no concurrent musculoskeletal comorbidities (Unlikely!) then just administer the above, saved programs to areas 1 and 2. Area 1: Thoracic spine from T3-T13. Area 2: Lumbosacral spine from L1-S3.
‘Areas’ 3 and 4 would be treated in any patients with concurrent hip dysplasia, DJD, atrophy, and/or weakness in the hips and rear legs. You would deliver the energy over the hips and proximal musculature in a standard fashion as described. You would use a standard hip setting for the appropriate-sized animal to treat areas 3 and 4 if needed. Area 3 and 4: Pelvis/Hips/Extremities
Recommended Treatment Plan:
Treat every other day or twice weekly for 6-10 sessions. Continue twice weekly or at least weekly indefinitely. Augmenting laser therapy and rehab with nutritional supplements, proper diet, weight loss, and other modalities or treatments can improve recovery even further.
As previously mentioned, for best results, a comprehensive physical rehabilitation program should be instituted in conjunction with laser therapy. This would include both in-clinic and in-home programs. The following procedures are recommended.
In-clinic rehab:
In-Home rehab:
As always, if you have any additional questions, please do not hesitate to contact us! Good Luck!
Sources:
Hamblin, Michael R. “Photobiomodulation, Photomedicine, and Laser Surgery: A New Leap Forward Into the Light for the 21st Century.” Photomedicine and Laser Surgery, vol. 36, no. 8, 2018, pp. 395–396.
Kathmann, Cizinauskas, Doherr, Steffen, Jaggy. “Journal of Veterinary Internal Medicine.” 2006;20:927–932.
