The spinal cord forms a vital link between the brain and the rest of the body. Without it, the brain and the body couldn’t communicate with each other. This is why when the spinal cord is injured, the transmission of nerve impulses for movement, temperature, pressure, and sensation, among others, are disrupted.
Spinal cord injury and current treatment
An injured spinal cord swells and because there is a restriction in blood flow, it results in further critical or permanent sensory, motor, and autonomic function damage. Rapid prevention of spinal cord injury is important to prevent more serious damage to such a fragile column of bones. Once the patient is at the hospital, doctors often focus on maintaining the patient’s ability to breathe and immobilizing the neck to prevent further damage to the spinal cord. Doctors may also use surgery to remove the tissue or fluid that presses on the spinal cord.
To date, the only treatment available for spinal cord injury is steroid therapy with methylprednisolone. However, there are certain guidelines on the use of steroids after an acute SCI. For instance, the methylprednisolone may not be used within the first 24-48 hours following the acute SCI. Such treatment is also minimally effective.
The novel spinal osmotic therapy device used in rats
Now, a group of researchers from the University of California – Riverside have introduced a novel spinal osmotic therapy device that removes water molecules from the spinal cord to help swelling and secondary swelling.
The study is led by Victor G. J. Rodgers, the Jacques S. Yeager, Sr. Professor of Bioengineering of the UCR, and Devin Binder, a biomedical sciences professor at the same University. The duo said that the osmotic therapy device is capable of gently removing the fluid from the spinal cord. Although it has only been tested in injured rats, they believe that it can also be scaled up for testing in humans.
Development of the spinal cord OTD
Rodgers and team shared via Science Daily that the osmotic therapy device comprises of a flat semi-permeable membrane separations structure that is mounted on a two-compartment housing with two ports. The purpose of this was to allow the tangential flow of an osmotically active fluid across the membrane on one side. When using the device, the osmolyte – compounds that influence the properties of biological fluids and with a primary role of maintaining the integrity of the cells – cannot pass through to the membrane but the ions and water can freely cross the barrier.
Meanwhile, the opposite side of the membrane is filled with a hydrogel and is put in direct contact with the tissue right to the point of spinal cord injury in rats. Their experiments show that fluids drain into the small chamber and then cycle again through the device, removing more water. It also allows recirculation, the authors added.
In previous studies, OTD has been used to remove water to prevent brain swelling and improve neurological outcomes. Rodgers and colleagues hope that the device could also be used in treating spinal cord injury. They also plan to conduct longer experiments on rats to improve the device before they eventually move to human trials.
Estimated water extraction rate by the OTD
Their study reads that the estimated water extraction rate of the device indicates that it is capable of removing more water than that associated with edema (swelling). The excess water during the test on a rat model is approximately 7.2 μL of fluid, they wrote.
As many as 450,000 people in the US alone are living with SCI, according to the National Spinal Cord Injury Association. Every year, about 17,000 new SCIs happen in the country and most of these are caused by the trauma in the vertebral column, affecting the spinal cord’s ability to receive and send messages from the brain to the body that control the autonomic, motor, and sensory function below the level of the injury.
American Spinal Injury Association (ASIA) grading scale describes the severity of the spinal cord injury. ASIA A means a complete spinal cord injury with no motor function or sensory preserved. ASIA B describes a sensory incomplete injury with complete motor function loss. ASIA C means a motor incomplete injury with some movement but less than half of the muscle groups are already anti-gravity. ASIA D describes a motor incomplete injury with more than half of the muscle groups are anti-gravity, which means it can still lift against the force of gravity with a full range of motion.
Motor vehicle accidents are the most common (39.3%) causes of SCI, followed by falls (31.8%), violence (13.5%), sports (8%), medical or surgical (4.1%), and others (3.1%). SCI as a result of falls is most common in the elderly. Since the vertebrae, discs, and ligaments that make up the spinal column wear and tear over time, older spinal columns are more prone to serious injury after a fall. This is the reason why the elderly population is always advised to watch their step or make sure that they hold onto a railing to help stabilize them. This is according to Sci-Info-Pages, a quadriplegic, paraplegic, and caregiver resource.
Furthermore, the leading act of violence that result in SCI is a gunshot. Another common cause is assault. Sports-related accidents can also cause SCI. Study shows that the sport that causes the most SCI in the US is diving if the diver hit their head in shallow waters. Other sports that result in SCI are horse-riding, cycling, football, and wrestling.
Of new SCI cases, about 78% are male and 22% are female. The average age at injury is 43 and the median age is 35.4. The majority of people with SCI are single (50.7%). Overall, 81% of SCI patients who survive in the first 24 hours after an injury are still alive 10 years later compared to 98% of people without SCI given similar gender and age.
Spinal cord injury consequences often extend beyond health. There are also social and economic consequences. The osmotic therapy device shows great potential to improve care and overcome barriers associated with the SCI.