Know your spinal cord – Brown-Sequard Syndrome
We’ve made it to day twenty in our little series on knowing your spinal cord. As always, you can find each and every post in this series through our neuroanatomy category. Since we’ve covered all the major neuroanatomy, the latest posts have been on spinal cord diseases and disorders. That said, today we’re covering Brown-Sequard syndrome, so let’s take a look at what this is.
Unlike the other disorders we’ve covered Brown-Sequard syndrome is not congenital. This is the first post that covers an actual spinal cord injury and we will probably cover a few of the special cases. In this case, you have a hemisection of the spinal cord, or damage to one half of the spinal cord. In this case, we can see how the decussation (which as we learned can happen in the medullary pyramids or depending on the tract inside the spinal cord) will have different effects on the sensorimotor function.
Named after the guy who found this (isn’t that how everything gets named?) in the 1850’s, when hemisection of the spinal cord occurs it results in paralysis and loss of proprioception on ipsilateral side (or the same side) as the injury or lesion, and loss of pain and temperature sensation on the contralateral side (opposite side) as the lesion. Not every incomplete lesion causes Brown-Sequard syndrome, below is an image showing some of the types of lesions, however only the bottom is classified as a Brown-Sequard.
This is one of the reasons we know where certain tracts decussate. Over the course of history there have been several examples of injury that have lead to discoveries about how the brain/spinal cord works and in the case of Brown-Sequard syndrome, we can clearly see which tracts decussate in the cord and which decussate in the medullary pyramids based on which side of the body is affected. In fact, below is an image showing the effect Brown-Sequard syndrome has on a person.
In this case, the injury clearly happened in the cervical area. However, this isn’t always the case and the level of injury will dictate the affected area. There are a lot of causes of Brown-Sequard, such as trauma, spinal tumor, ischemia (blocked blood vessels), or diseases like tuberculosis can cause this type of injury. So now for the bad news, there is no fix as of now. That isn’t to say we aren’t working on it, but neural engineering is hard and we barely have a handle on the basics.
The treatment for Brown-Sequard syndrome is just as rudimentary and involves first attempting to fix what caused the damage to stop it from making the problem worse. That might entail surgery, medication, or a number of other options like steroids to reduce inflammation. The second line of treatment is physical therapy, which is the space where most of our labs research exists in. Things like spinal cord stimulation (for pain or rehabilitation), assistive exoskeletons, and basics like weight lifting and stretching are the main ways we deal with this.
As we go on, you’re going to find out very quickly that there is very little we can do for the spinal cord right now. In my mind, the spinal cord and it’s neural circuitry is much simpler than the brains, maybe not a lot simpler, but definitely less complex. This is why I feel that a better way of trying to tackle understanding the brain, consciousness, and it’s diseases, we would be better suited trying focusing on the spinal cord first. After all, the spinal cord can talk to the brain and the muscles, this makes it a sort of the rosetta stone of the body.
Tomorrow we can talk about other unique presentations of spinal cord injury. I haven’t quite narrowed down the topic yet, I’ve been quite busy, but I’m working on it now. So you’ll just have to wait to see.
Until next time, don’t stop learning!