Examining the chronic complications of spinal cord injury

Spinal cord injuries can lead to a cascade of downstream health challenges. For example, many individuals are more susceptible to infections and also have greater difficulty healing wounds or other injuries. “When you damage the spinal cord, you break the communication between the spinal cord and the immune system. As a result, the immune system works less efficiently,” says Phillip Popovich, PhD, director of the Center for Brain and Spinal Cord Repair. His laboratory focuses both on understanding this connection and finding ways to treat or prevent this problem in patients.

Researchers have known that spinal cord injury in the head or thorax can interfere with fundamental reflexes that most people take for granted. When these reflex circuits aren’t regulated—autonomic dysreflexia—blood pressure elevates and patients face an increased risk for stroke and cardiovascular problems. In a study published in the Journal of Neuroscience, Popovich and his colleagues have connected those problems within the reflex circuits to the immune system in a mouse model and in humans. “In someone with a spinal cord injury, not only is that reflex control lost, it can stimulate a real pathological change in how it controls the immune system. It can drive down immune function and cause immune suppression,” he explains.

Popovich and his team have found that PAM2CSK4 protect immune cells from this exaggerated reflex in mice in the short term. So he and his colleagues are trying to design better drugs that would allow them to pre-treat the immune system for defined periods of time. Such a scenario could allow these immune-compromised patients to receive potentially life-saving vaccinations.

But the immune suppression reflex is likely permanent, Popovich says, which means that they’re also looking at ways to shut it down without causing cardiovascular effects. “We’re also trying to use the mouse model to manipulate the spinal circuitry, to ‘fix’ the broken reflex,” he says. “If we can do that, then we might be able to contain these out-of-control reflexes.”

Read the complete Journal of Neuroscience article.