Laurie's Blogs.

In this week’s blog I wanted to review an article that I found quite fascinating:

Jeffery ND, Barker AK, Hu HZ, et al.  Factors associated with recovery from paraplegia in dogs with loss of pain perception in the pelvic limbs following intervertebral disk herniation.  J Am Vet Med Assoc  248 (4): 386-394, 2016.

Background

Thoracolumbar intervertebral disc herniation (IVDH or IVDD) is more common in chondrodystrophic dogs due to their accelerated intervertebral disc degeneration.

The resultant injury to the spinal cord almost always involves a contusion component and a compression component.

The prognosis for surgically treated dogs with thoracolumbar IVDH varies and appears to be particularly predicted by the presence of absence of deep pain perception in the pelvic limbs (although the subject is controversial).  Dogs that retain deep pain have excellent prognosis for recovery of the ability to walk independently.

Information is lacking to help clinicians predict whether a dog without deep pain perception will recover its ability to walk again.

The purpose of this study was to investigate association between recovery of locomotion and prognostic factors in dogs with loss of deep pain perception in the pelvic limbs caused by IVDH between T10 – L3.

Materials & Methods

This was a prospective cohort study with cases collected from three university centres from November 2011 to February 2014.

All dogs included had a history taken and physical and neurological examination.  All had paraplegia and absence of deep pain perception.  MRI or CT imaging were conducted on the dogs and dogs were subsequently treated  in accordance with the recommendations of the attending clinician and wishes of the owners.  The MRI or CT scans of each dog were examined independently by two observers.

The primary outcome assessed was the ability to walk independently within 3-months after spinal decompression surgery.  Choice of decompressive surgical technique was made by each surgeon and tailored to the specific lesion.

Post-operative care consisted of opioid analgesics, manual bladder expression, and physical therapy tailored to each dog’s requirements.

Results

There were 93 dogs included for consideration in the study.  Exclusions from the study were made due to lack of imaging, euthanasia, or signs of myelomalacia, leaving 78 dogs remaining for inclusion.  

Forty-four dogs were Dachshunds ad the remaining 34 were various small- to medium-sized purebred dogs or dogs of mixed breeding.

Outcome

45 (58%) dogs had recovery of independent locomotion within the 3-months follow-up period.  Median interval to recovery for all dogs was 49 days.

Of the 33 dogs that did not recover, 10 (13% of all dogs) developed signs consistent with progressive myelomalacia.

Prognostic factors associated with outcome

Evaluation of the data revealed that none of the factors hypothesized to be associated with the recovery of locomotion (age, compression ration, duration of clinical signs, delay between onset of loss of independent locomotion and initial referral evaluation, or corticosteroid drugs received) were significantly associated with prognosis.  

Discussion

The results of this paper contradict the results of other retrospective studies.  The power of this study is the numbers of dogs followed is much higher than any of the previous studies, the prospective nature of the study, the almost complete follow-up information on all dogs, and the multicenter involvement.

One conclusion to be drawn is that the prognosis for ambulation after loss of deep pain sensation is already fixed at the point of injury (i.e. the damage may be irreparable in some dogs).  Additionally the data also suggests that immediacy of surgery for a dog lacking deep pain perception does not affect outcome.

The researchers suggest that blood flow in the area is likely the more important determinant to successful recovery in these dogs and that future studies should focus on detection of blood flow and biomarkers for such in IVDH cases in dogs with paraplegia and lack of deep pain.

WHAT DOES THIS MEAN TO REHAB PROFESSIONALS? – Laurie’s thoughts…

So right off the bat, if the dog is paralyzed and has loss of deep pain, there is at best a 58% chance of recovery with surgery.  And surgery may not have had anything to do with that success rate.  Blood flow likely does!  (And I’ve been saying this for decades… increase blood flow to help the spinal cord.  There’s a paper – Joaquim et al, 2010, JAVMA -  that looks at acupuncture for dogs with grades 4 or 5 neurologic signs >48 hours that found that acupuncture was more beneficial than surgery alone or surgery plus acupuncture.  What does acupuncture do –as an oversimplification?  Increases blood flow!)  So post-operatively or non-operatively, these dogs need to go for rehab / physio and likely rather intensively in the early stages for therapies targeting increasing blood flow to the spinal cord.  My favourites:  Laser, acupuncture (or TENS or E-stim if no acupuncture is available), PEMF, Traction (i.e. tail pulls), and home heating or icing of the area (or both using a contrasting hot pack x 30 sec, cold back x 30 seconds regimen for 10 minutes total.)  Ultrasound could be used, if the area was clipped so at to remove the impedance of the hair in delivering this mode of energy transfer.  Anything that increases circulation without concurrently increasing pain could be utilized… so perhaps massage distal to the injury or even radial shockwave distal to the injury, other mobilizations distal to the injury (all within pain tolerance) could be considered as well.

So, bottom line, GET THESE DOGS TO REHAB AS SOON AS POSSIBLE!