Treatment of Conus Injury vs. Cauda Equina Injury

[Wise Young]

A member of carecure sent me the following question"

Please can you tell me in your opinion if cord blood stem cells would have any benefit in helping with an L1 spinal cord injury? I really don’t know if the injury is Conus or Cauda Equina , I have asked my doctor but they can’t seem to make up there mind. I can tell you that the bowl and bladder is flaccid, nothing below the knees, Weak core muscles, I don’t know if this would help with the diagnosis. If you believe cord blood stem cell would not have any benefit, what in your opinion would be a helpful treatment, if any as I really value your opinion. Thank you so much for your time.

There is no evidence at the present that umbilical cord blood infusions (intravenous) would be of benefit now for spinal cord injury. I am very sorry. We are studying umbilical cord blood stem cell transplants into the spinal cord and so far have not seen the kind of improvement that would lead me to recommend that treatment yet. It is possible that there may be a way of growing stem cells from umbilical cord blood that would be useful but this, in my opinion, has not yet been achieved. I am very interested in the results of the Korean woman who received umbilical cord blood transplants but I am not yet convinced that she has recovered all that much. By the way, it seems that she did get decompression at the time of her surgery and her injury was at T12-L1.

Based on your description of an injury to the L1 vertebral level where the conus is located, the presence of flaccid bowel and bladder, and loss of function below the knees, it is likely that you have had a conus injury. A conus injury would damage the sacral segments of your spinal cord where S1 would be the muscles of your foot, S2-3 would be your bladder, and S4-5 would be your anal sphincter. On the other hand, I agree with your doctors that conus and cauda equina injuries are difficult to distinguish. Here are some clues, however, that might help you distinguish between them.
1. A conus injury often involves just the sacral segments and lower lumbar segments. Do you have weakness of your quadriceps and hip flexors? If so, this would be more consistent with a cauda equina injury.
2. Do you have any sparing of muscles in your legs, i.e. one side is better than the other? Generallly, cauda equina injuries tend to affect one side more than the other whereas a conus injury involves both sides equally.
3. Cauda equina injuries often are associated with some return of function, particularly motor function after injury, often on one side more than the other. Have you recovered function after injury and where?

The axonal regenerative therapies that are currently in clinical trial is not likely to produce dramatic results with a conus injury because this means that the neurons in your sacral spinal cord have been damaged. You will probably need motoneuronal replacement therapies. At the present, the only cells that have been shown to replace motoneurons are embryonic stem cells. Several groups, including ours, are working on fetal neural stem cells, umbilical cord blood stem cells, and bone marrow stem cell therapies for neuronal replacement but I don't think that any of these have been shown to work yet. However, I believe that motoneuronal replacement therapies are achievable and we continue to work hard on it.

Here are some possible approaches, however, that you may want to consider in the meantime. First, make sure that you have been adequately decompressed. Make sure that there is no bone that is continuing to press on the conus or cauda equina. This should be apparent on MRI. Second, you should ask your doctors if there is any tethering of your cauda equina. Although this may be hard to discern on MRI, sometimes tethering can be seen. If either or both are present, you may want to consider surgery to decompress and untether the cauda equina because this may result in some functional return. Third, in China, I know that they have been bridging from interconstal peripheral nerve above the injury site to peripheral nerves to the bladder and anal sphincter, leading to some restoration of bladder function and anal sphincter. Unfortunately, I don't know of any place in the United States that are carrying out such surgery. Fourth, if you have spinal root injury, there is the possibility that transplantation of olfactory ensheathing glia (OEG) cells into the dorsal root entry zone may encourage reentry of sensory axons back into the spinal cord and the restoration of some sensory function. Finally, as I point out above, I believe that there will be motoneuronal replacement therapies in the coming years. So, keep tuned and don't lose hope.

I hope that this is helpful.

Wise.

[jimbo71]

Dr Young,

You mentioned that conus and cauda equina injuries will probably not show dramatic improvement from axon regeneration therapies. is it possible that we could see some improvement such as bowel, bladder, and sexual function with these regeneration therapies?

[Wise Young]

Originally Posted by jimbo71

Dr Young,

You mentioned that conus and cauda equina injuries will probably not show dramatic improvement from axon regeneration therapies. is it possible that we could see some improvement such as bowel, bladder, and sexual function with these regeneration therapies?

Jimbo, I am not sure that I understand your question. Are you asking whether it is possible that bowel, bladder, and sexual function function may improve with regenerative therapies if you do not have conus injury? If you have conus injury, axonal regenerative therapies alone are probably not enough and some neuronal replacement therapies will be required. If you have higher injuries that have interrupted the connections to your conus but the conus is intact, then regenerative therapies should be able to restore some function.

Wise.