Understanding the Limbic System’s Role in the Symptoms and Treatment of Multiple Chemical Sensitivity

by Dr. Susan Tanner, MD

In our last article, we discussed multiple chemical sensitivity, or MCS. We outlined the main characteristics and symptoms of MCS, how it usually develops and presents in sufferers, and some of the biological/biochemical interventions that have been proven to be helpful in treating it. If looking at the disorder more holistically, though, our discussion would be incomplete without also addressing the neurological impacts of MCS—both cognitive and psychological.

The Neurological Impacts of MCS

Many sufferers of MCS are reluctant to explore or consider the neurological component of the disorder, mainly because, unfortunately, they have been made to feel that their symptoms are “all in their heads.” Many sufferers have even been told that they are manifesting “imagined” symptom and not dealing with a “true” illness. The stigma of being labelled as having a mental disorder, rather than a physical one is exacerbated by the attitude of dismissal of their symptoms by both medical professionals and friends and family. Feelings of anxiety, isolation, and depression are prevalent among MCS patients. As a result, most sufferers resort to hiding their suffering or completely avoiding all things that cause reactions, rather than continuing to seek medical treatment. Sadly, while avoidance can be helpful, in not seeking treatment, the patients’ suffering and symptoms often continue to get worse.

I feel strongly that it is important to put aside any preconceived notions of mental health disorders when dealing with chronic illness. MCS patients, in particular, ARE dealing with something that is affecting both their bodies and their brains. As a matter of fact, in treating these patients we have learned that a series of nerve pathways have often been damaged or disrupted (usually by toxins, an infection, virus, or trauma). The disruption is what creates the physical sensations and visible reactions to chemicals, scents, smells, dyes, medications, foods, textures, etc., that are so debilitating. Unfortunately, the full impact of any chronic illness, especially as it affects the wiring of the brain and nervous system is often not discussed as part of a treatment plan.

MCS and the Brain

To fully discuss brain chemistry and function is well beyond the scope of this article, but I do want to touch on the limbic system, how it is impacted, and how it affects many areas of brain function.   The limbic system, to keep it simple, is the complex network of nerves in the cerebral cortex, which is the outermost part of the brain. It affects mood, stability, and a host of other reactions. The limbic system is under the control of hormones and biochemical compounds, and responds electrically to stimulate different centers of the cerebral cortex. Over time, these responses can become somewhat hard-wired, in that they happen very quickly with less and less stimulation. To make things even more complex, the mechanisms that control the release of certain brain chemicals can become erratic allowing sudden and large outpourings of neurotransmitters such as dopamine, norepinephrine, and serotonin, followed by sudden cessations or withdrawals of these compounds. Rather than responding “normally” to outside stimuli, the limbic system then responds times 100, in what is often termed the “flight or fight” response, sometimes, even getting stuck in a state of hypervigilance. For example, some MCS sufferers experience instant skin flushing and prickly sensations and/or nausea when they smell certain scents–magnified physical reactions that do not even require contact with the substance. These experiences can feel hopeless and very out of control for the sufferer. Without proper intervention, a vicious, cycle can then evolve, often manifesting clinically with an anxious, depressed, or seemingly obsessive patient.

Causes for Limbic System Imbalances

Chemical exposures in a sensitized patient can set this limbic system imbalance into motion, but it can stay imbalanced by the nature of the system itself. This is the reason that full MCS treatment involves addressing the limbic system as well as all of the other detoxification modalities laid out previously.

Any type of trauma, whether it be from chemical exposure, from physical damage, or from emotional distress can affect the wiring of the limbic system. Color uptake studies of the brain show that areas of the cerebral cortex actually can become damaged by the ongoing nature of these traumas. But, the good news is that the brain can heal when the faulty pathways and trauma are properly addressed.

Treatments for MCS that Address “Rewiring” the Limbic System

  1. Targeted amino acid/nutritional therapies. These can help keep levels of neurochemicals in better supply. This treatment is done after specific testing, as each patient may have different needs. Treatment may include supplementing with 5HTP, L-tyrosine, GABA, and phosphatidylserine, among others.
  2. Talk therapy. The old Freudian analysis is not what I am referencing here. Cognitive behavioral therapy helps to reframe the trauma and retrain the response that the brain automatically tries to take. Over time and with diligence, this therapy can change those faulty wirings. It must be remembered that “thoughts are things” and as such, can be helpful or hurtful to the body. An excellent book on this subject is The Molecules of Emotion by Candace B Pert, PhD.
  3. Gentle martial arts, such as Qi Gong or Tai chi, which combine breathing strategies with physical movement. These work extremely well in calming the limbic system and gradually helping to rebalance it.
  4. Neurofeedback. This looks like a brain wave study, but patients are taught through concentration and breathing to actually control reactions in the system.
  5. Working with a reiki practitioner, acupuncturist, or therapeutic massage practitioner. These are types of body work that are quite affective in changing the programming through physical stimulation and manipulation.
  6. Prescription Medications. While they are not a first choice, helping get chemical levels in order sometimes must be done in order to proceed with and get the full benefit from some of these other treatment modalities.

The main takeaway with this article is that while MCS is a real illness with physical symptoms, the resulting brain and psychological impacts must be treated as well for full recovery. Post-traumatic stress disorder (PTSD) is not at all uncommon in this type of illness and can continue to be devastating even when physical healing has largely been accomplished.