A prescription drug used to prevent stroke complications may help preserve and repair the nerve damage caused by multiple sclerosis (MS), according to a review of animal studies. The medication, nimodipine, was linked to reduced inflammation, less nerve damage, and lower disease severity in several preclinical models, suggesting it could be repurposed as an MS treatment.

How Does MS Damage the Nervous System?

In MS, the immune system mistakenly attacks myelin, the fatty protective coating around nerve fibers that helps them send electrical signals. This attack causes inflammation and nerve damage that disrupts communication between the brain and the rest of the body, leading to a wide range of neurological symptoms. Most current MS treatments work by modifying the immune system to reduce relapses and slow disease progression, but they generally do not directly repair myelin that has already been lost.

What Did the Animal Studies Show About Nimodipine?

Researchers in Iran reviewed five animal studies investigating whether nimodipine could have potential as an MS treatment. Four studies involved rodents with experimental autoimmune encephalomyelitis (EAE), a condition commonly used to model MS, and one used cuprizone, a toxin that causes demyelination, or loss of the protective myelin coating around nerves.

Because the studies differed substantially in their design, the researchers conducted a narrative review rather than combining the results into a single statistical analysis. Overall, nimodipine reduced disease severity in the EAE models. The drug was associated with several beneficial effects:

• Reduced relapse severity: In one study, nimodipine reduced the severity of relapsing-remitting EAE and lessened disease severity during the early active phase.
• Improved myelin repair: Nimodipine was linked to less myelin loss and fewer demyelinated nerve fibers. In one study, treatment increased the number of nerve fibers showing signs of remyelination, the process through which damaged myelin is rebuilt.
• Reduced inflammation: Animals treated with nimodipine showed fewer signs of inflammation in the brain and spinal cord and lower blood levels of some inflammation-related proteins.
• Better blood flow: The drug was linked to improved blood flow and oxygen levels in the spinal cord, while one study found reduced clinical scores and improved motor performance.
• Enhanced nerve protection: Other studies reported reduced relapse rates, fewer sensory and motor problems, and effects suggesting protection of nerve cells.

In the cuprizone model, where demyelination was triggered by a toxin rather than an autoimmune attack, nimodipine was associated with fewer reactive immune cells in the brain and with faster, more complete myelin repair.

How Does Nimodipine Work?

Nimodipine is a prescription drug widely used to prevent blood vessel spasms following bleeding in the brain. It works by relaxing narrowed blood vessels to improve blood flow to injured brain tissue. Previous research has suggested that the drug may also reduce inflammation and nerve damage while supporting myelin repair, making it a candidate for drug repurposing, a strategy that finds new uses for medications already approved for other conditions.

"These findings underscore the potential of drug repositioning to uncover novel clinical mechanisms for nimodipine and expand its therapeutic applications to other diseases, such as MS," the researchers wrote.

Researchers, Study published in Brain Research

What's Next for Nimodipine as an MS Treatment?

The researchers called for further studies to reproduce the findings and early-stage human trials to determine whether nimodipine can safely provide similar benefits for people with MS. While the animal data are promising, translating these results to human patients will require careful clinical investigation to establish both safety and efficacy.

The potential of nimodipine represents an important example of drug repurposing in MS research. Rather than developing entirely new medications, researchers are exploring whether existing drugs with established safety profiles might address unmet needs in MS treatment, particularly the challenge of promoting myelin repair.