Neuroprotection for neurological disease
Researchers are looking for ways to protect the body after acute events, such as a stroke or nervous system injury, and to help people with conditions that affect the nervous system, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis (MS).
Current neuroprotectors cannot reverse existing damage, but they may protect against further nerve damage and slow down any degeneration of the central nervous system (CNS).
Scientists are currently investigating a wide range of treatments, and some are already in use today. Some approaches may help with more than one condition, as different neurological conditions often share the same features.
What causes neuron damage?
Different conditions that relate to the CNS can have different symptoms, but the processes by which neurons, or nerve cells, die are often similar.
Scientists currently believe that these processes include:
Neurological damage underlies a range of health issues.
Certain chemical reactions in the body produce waste substances called free radicals. These electrically charged particles occur in an oxygen-rich environment. They can interact, affect other substances, and cause cell damage.
The body can remove unwanted free radicals, but if it cannot remove them all, oxidative stress can occur.
Mitochondria are specialized structures within cells that generate energy.
Nerve cells can die in the brain if they become overactivated.
Glutamate, a brain chemical, excites the interaction between nerve cells. It is an important step in neurotransmission, which is the process of passing of information from one nerve cell to another.
However, too much glutamate can result in cell destruction. Overstimulation of nerves by nerve impulses can result in damage or loss of function.
Excitotoxicity is a key factor in nerve damage following a stroke.
Inflammation is an essential part of the body's immune response. It can occur anywhere in the body when the immune system reacts to a foreign organism or infection. It can also occur after cell damage or injury as the body tries to repair itself.
When inflammation occurs in the brain or CNS, it can result in the death of neurons
It can contribute to cell death in Alzheimer's, Parkinson's, and infections of the brain and the CNS.
The buildup of iron in the brain may play a role in degenerative diseases such as Alzheimer's, Parkinson's, and ALS, possibly as part of a cycle of excitotoxicity and cell death.
Researchers are looking for substances that may help remove excess iron from the CNS. Using these substances to remove iron could potentially restore balance to the brain and CNS.
In dementia, certain proteins build up in the brain.
There appears to be a link between high levels of TNF, excitotoxicity, and high levels of glutamate.
Types of neuroprotection
Neuroprotection aims to:
- limit nerve death after a CNS injury
- protect the CNS from premature degeneration and other causes of nerve cell death
Neuroprotective agents counter the effects of neurodegeneration, or nerve breakdown.
Several types of substance have neuroprotective effects:
Free radical trapping agents
These convert damaged and disease-causing unstable free radical cells into molecules that are more stable and easier for the body to manage.
Antioxidants can interact with and reduce the impact of free radicals. They are present in foods, especially plant-based foods, and supplements.
Scientists do not know exactly how they work. Their mechanism of action seems to depend on both the condition they are targeting and factors unique to each individual.
Vitamin E, for example, has shown antioxidant properties in Alzheimer's and, to a lesser degree, ALS.
However, research has also suggested that vitamin E supplementation can make brain function and dementia worse in some people.
It is important to talk to a doctor before using any herbal products, over-the-counter medications, or supplements.
Many products can interact with other medicines to produce unwanted side effects.
Anti-excitotoxic agents may help manage involuntary movements.
Glutamate is an excitatory neurotransmitter. It is necessary for normal nerve cell function, but too much may be harmful.
Stopping glutamate from reaching some cells by blocking glutamate receptors, for example, may prevent overstimulation and degeneration.
Amantadine, which is one treatment option for Parkinson's, may help reduce Parkinson's-related dyskinesia, or involuntary movements.
It seems to work by changing the interaction between glutamate and another brain chemical.
However, side effects including hallucinations, blurred vision, confusion, and swelling of the feet can occur.
Apoptosis, or programmed cell death, refers to the natural death of cells as the body ages and grows.
These can relieve pain as well as reduce the inflammatory processes that may worsen Parkinson's and Alzheimer's.
One group of biomolecules called neurotrophic factors can promote neuron growth.
Scientists are looking into ways of delivering these protein molecules for treatment purposes.
Some people with Alzheimer's, Parkinson's, or ALS appear to have higher-than-normal iron levels.
For this reason, some scientists believe that lowering iron levels may help with these conditions. Substances that remove extra iron from the body, or iron chelators, may help.
In one study, scientists found that iron-binding treatment improved the condition of rodents with an Alzheimer-like disease. More studies are needed to confirm these results, however.
It is unclear what role stimulants might play in the development of brain functioning problems such as dementia.
In the past, animal studies have suggested that caffeine may have neuroprotective properties.
However, a 2015 review of research on caffeine use and dementia concluded that it was neither preventative nor harmful to brain function.
Scientists are looking into gene and stem cell therapies for neurological diseases.
The blood-brain barrier prevents infections and viruses from entering the brain, but it can also stop treatments from reaching the brain. This makes it hard to deliver a treatment directly to the brain.
Gene therapy, which involves identifying and replacing a disease-causing gene, could solve this problem.
However, as with many neuroprotective agents, research has not yet confirmed that gene therapy is consistently effective.
Stem cell therapy
Research is ongoing as to how scientists might use stem cell technology to regenerate body cells, including nerve cells.
Alzheimer's, Parkinson's, and MS are common conditions that affect the nervous system and can reduce a person's quality of life.
Research into neurodegenerative conditions and possible neuroprotective therapies is rapidly progressing. Scientists hope that they may lead to a cure or the development of effective treatment for a range of conditions in future.
For now, however, many of these options need more research to confirm that they are safe and effective.
How far along are these types of treatments? Are many already in use?
Currently, people use anti-inflammatory medications and supplements when inflammation is a major part of the condition, such as in MS. No neuroprotective medications have approval at this time, but there is a great deal of research into their effects.Heidi Moawad, MD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.