Can our nerves be poisoned? Let's talk about neurotoxicity!

Do you sometimes feel dizzy for no reason? Do your limbs go numb? Or do you feel like your memory is getting worse, or it's hard to keep your mind in one place? Maybe the reason for this is something we don't even think about. That is neurotoxicity, or as we call it in medical terms, a condition called neurotoxicity . Let's talk about this in a little more detail today, okay?

Simply put, what is neurotoxicity?

Neurotoxicity is when naturally occurring or man-made toxins (called neurotoxicants) in the air we breathe, the water we drink, the food we eat, and some of the things we use damage our nervous system. Did you know that our nervous system is a very complex network? It includes our brain, spinal cord, and nerves throughout our body . These are the ones that control everything we think, do, say, and feel.

So, these toxins can cause changes in the functioning of the nervous system. These changes can sometimes be minor, and sometimes very severe . While some changes can be treated and cured, some may be lifelong. In the worst cases, this neurotoxicity can even lead to death . Imagine how dangerous that is!

Sometimes, even things that are normally not toxic to us, for example, some medications, can cause neurotoxicity if taken in excess. Or, there are some substances, like lead, that can be toxic even in small amounts.

This neurotoxicity can occur during fetal development , child development , or adulthood . However, the damage caused by exposure to these toxins during fetal and early childhood is usually greater. Also, people with certain diseases, for example, those with jaundice (hyperbilirubinemia) or those with diseases such as Charcot-Marie-Tooth Disease (CMT), are at higher risk of developing this neurotoxicity.

What are these neurotoxicants?

In fact, there are hundreds of types of these nerve agents. They can be in gaseous, liquid, or solid form. Some toxins can cause symptoms even in very small amounts, or after a single exposure. While others require large amounts and prolonged exposure to cause symptoms.

Here are some examples:

• Heavy metals: For example, lead, mercury.
• Other naturally occurring substances: For example, carbon monoxide, arsenic, and trichothecene mycotoxins from some molds.
• Insecticide:For example, `(organophosphates)` and `(chlorpyrifos)`. These are used in our farming, right?
• Solvents found in factories and cleaning products: For example, `(tetrachloroethylene)`.
• Manufacturing materials: For example `(vinyl chloride)`, `(toluene)`, `(formaldehyde)` and `(polybrominated diphenyl ethers) (PBDEs)`.
• Drugs and Alcohol: Alcohol, Amphetamines, Opioids, Inhalants, and Cocaine.

There are also chemicals that affect our hormonal systems, called Endocrine-disrupting chemicals (EDCs). Examples include Bisphenol A (BPA) (found in some plastics), phthalates, and polychlorinated biphenyl compounds (PCBs). These can indirectly cause neurotoxicity.

The relationship between medications and neurotoxicity

Did you know that some medications, for example, some antibiotics and even some antipsychotics, can cause neurotoxicity for various reasons? But in most cases, the benefits of these medications far outweigh the risks of neurotoxicity . That's why doctors prescribe them with great care.

Some medications, especially those used in cancer treatments, can also cause neurotoxicity.

• Platinum-containing drugs: `(oxaliplatin)`, `(cisplatin)`, `(carboplatin)`
• Taxane drugs: `(paclitaxel)`, `(docetaxel)`
• Vinca alkaloids: `(vincristine)`, `(vinblastine)`
• Proteasome inhibitors
• Thalidomide analogs

Not only chemotherapy, but radiation therapy can also damage the central nervous system and cause neurotoxicity.

How common is this condition?

In fact, it's hard for researchers to say exactly how common this condition is, given the sheer number of types of nerve agents and the variety of symptoms. However, researchers say that our exposure to these nerve agents is widespread .

Let me give you two examples to help you understand the extent of this:

• One study found that there are about 385 million accidental poisonings from pesticides worldwide each year , resulting in about 11,000 deaths each year.
• It is also estimated that about one million people die each year from lead poisoning . One in three children worldwide – that’s about 800 million children – have high levels of lead in their blood . Imagine how serious this is! Lead can be found in paint in old houses and in some toys.

What are the symptoms?

Symptoms of nerve agent poisoning can vary greatly. It depends on the type of toxin you were exposed to. Symptoms can range from mild to severe . Sometimes symptoms can appear immediately after exposure to the toxin, or they can take weeks, months, or even years to appear.

Here are some physical symptoms:

• Problems with balance and coordination (not being able to walk properly, having trouble grasping things)
• Diarrhea (stomach ache)
• Tiredness, fatigue
• Headache
• Appetite
• Pain conditions such as neuropathic pain
• Muscle problems: weakness, cramps, twitching
• Nausea and/or vomiting
• Numbness in the limbs
• Sleep changes: such as insomnia
• Difficulty speaking, slurred speech (dysarthria)
• Vision problems or vision loss

Now let's see what the mental and cognitive symptoms are:

• Behavioral changes or problems
• Decreased intellectual abilities, for example, mild cognitive impairment
• Dizziness or disorientation
• Executive dysfunction: This means difficulty controlling emotions and being unable to concentrate.
• Becoming angry more quickly than usual, becoming aggressive
• Memory loss
• Mood changes

The most important thing is to see a doctor if you or your child notice any changes or problems in their thinking, behavior, mood, or physical health . This could be due to neurotoxicants, but there could be other causes.

Symptoms that indicate an emergency

Sometimes neurotoxicity can be very sudden and severe (acute neurotoxicity). These symptoms can appear suddenly. If you have any of the symptoms below, you should go to the hospital immediately. Call 911 (1990 in Sri Lanka) or go to the nearest hospital.

Symptoms of acute nerve poisoning may include:

• Changes in heart rate
• Confusion or delirium
• Loss of consciousness
• Psychosis, including hallucinations
• Seizures
• Significant changes in body temperature (very high fever (hyperthermia) or very low body temperature (hypothermia))
• Sudden onset of extreme muscle weakness
• Sudden vision problems or loss of vision
• Difficulty breathing

What are the causes of nerve poisoning?

Simply put, neurotoxicity occurs when the aforementioned neurotoxicants damage, alter, or kill cells in our peripheral or central nervous system. Most often, this affects nerve cells, or neurons . You know, these neurons are the main ones that transmit and process signals in our brain, spinal cord, and peripheral nerves. Not only neurons, but other parts of the nervous system can also be damaged, for example , the myelin that covers the nerves.

Because our nervous system is such a complex system, damage caused by neurotoxicity can manifest in a variety of ways. Here are a few examples:

• Changes in the levels of neurotransmitters (for example, dopamine), an important chemical in our brain, and their signaling.
• Inflammation, or swelling, of the brain or spinal cord (neuroinflammation).
• Structural changes in the brain, for example, changes in the volume of gray and white matter in the brain.
• Damage to the myelin sheath surrounding peripheral nerves.

Exposure to nerve agents

There are various ways these nerve agents can enter our bodies:

• By breathing
• Through food or drink (from things you eat or drink)
• By absorption through the skin

These toxins can also affect a fetus. If these toxins enter the mother's body during pregnancy, they can pass through the bloodstream to the fetus through the umbilical cord . That's why some medications are not recommended during pregnancy, because they can have neurotoxic effects on the fetus.

When these toxins enter our bloodstream, they can cross the blood-brain barrier (BBB) ​​that protects our brain and directly affect parts of the central nervous system. Or, like the previously mentioned EDCs, they can affect the brain indirectly by altering other body systems.

There are many places where you can be exposed to these nerve agents, because the sources of these toxins are spread everywhere.

• Environmental pollution: vehicle exhaust, emissions from agriculture, emissions from factories.
• Local pollution: In places like parks, schools, or from chemical accidents in the area.
• Household pollution: From some household items, food and drinks. For example, some cleaning liquids, insect sprays, and paints.

What are the possible complications?

We have already discussed that some neurotoxicants can cause chronic neurological conditions . In severe cases, even death can occur.

Exposure to certain neurotoxicants, especially during fetal development and early childhood, has been found to be associated with several of the following conditions:

• Attention-deficit/hyperactivity disorder (ADHD)
• Learning disabilities
• Depression
• Anxiety
Schizophrenia-emotional `(Schizophrenia)`
• Autism spectrum disorder (ASD)

But it's important to remember that this only suggests a link between exposure to neurotoxins and these conditions. Researchers still don't know for sure whether these toxins directly cause these conditions. They are continuing to study all the possible effects and complications of these neurotoxins.

How do you find this? (Diagnosis)

Because there are hundreds of types of nerve agents and the symptoms of nerve agents vary widely, a diagnosis may require a number of tests and exams. Your doctor will first ask you about your symptoms and medical history . Then they will perform physical and neurological exams.

In addition, the following tests may be recommended:

• Behavioral assessment
• Blood tests
• Cognitive tests
• Electroencephalogram (EEG)
• An eye exam
• Imaging tests such as a brain MRI scan
• Nerve conduction study and electromyography (EMG)
• Neuropsychological testing and assessment
• Cerebral spinal fluid (CSF) analysis (Spinal tap / Lumbar puncture)

In some cases, doctors may not be able to find the exact cause of the symptoms of neurotoxicity.

What are the treatments?

Treatment options depend largely on your symptoms and the type of neurotoxin that is causing them. Treatment usually involves eliminating or reducing exposure to the toxin, then treating or managing the symptoms .

What is the outlook? (Prognosis)

The outlook for someone with a neurotoxicosis depends on many factors, including:

• What kind of nerve agent was exposed?
• How much exposure was there?
• How long was the exposure?
• How much damage has been done to the nervous system?
• Your age and overall health

Exposure to some nerve agents can be fatal. In some cases, even if the exposure is life-threatening, the nervous system may not fully recover. In other cases, full recovery is possible after treatment.

How do you avoid this? (Prevention)

To be honest, given how pervasive these nerve agents are in everyday life, it's difficult to completely avoid them all . However, there are a few things you can do to reduce your risk of exposure:

• Install a carbon monoxide detector in your home, and change its batteries once a year.
• Never mix cleaning products or household chemicals together. Doing so can have dangerous, even fatal, results.
• Have your home tested for other harmful toxins, such as lead.
• Keep your windows closed on days with poor air quality (high air pollution).
• Avoid using drugs and alcohol.
• If you are pregnant, talk to your doctor about exposure to nerve agents and how it may affect fetal development.

Most importantly, protecting yourself and your family from these nerve agents is not your responsibility alone. It is the collective responsibility of state and local governments, companies, and citizens alike. Institutions like the National Institute of Environmental Health Services (NIEHS) continue to research how the environment and nerve agents affect human health.

Finally, things to remember

Neurotoxicity can be caused by a variety of things and can cause a variety of symptoms. While it is difficult to avoid all neurotoxicants, there are things you can do to protect yourself and your family. If you or your child has any neurological symptoms, or if you have concerns about exposure to neurotoxicants, be sure to see a doctor. They are here to help.

` Neurotoxicity, Nervous system, Toxins, Symptoms, Brain health, Prevention