An Overview of Toxic Metabolic Encephalopathy: An Acquired Brain Injury

By Kristen Schreier, M.A., CCC-SLP, CBIST, HealthSouth Rehabilitation Hospital of Toms River

Have you known someone who experienced a change in his or her physical functioning or thinking skills after an infection or anesthesia? This change is often diagnosed as encephalopathy. Symptoms can develop suddenly and disappear within a few hours. However, for some, encephalopathy can be more serious, especially if you have a history of dementia or previous brain injury. One type of encephalopathy with an increased potential for lasting effects is toxic metabolic encephalopathy (TME).

Toxic is defined as something composed of or containing poisonous material capable of causing serious debilitation. Your body’s metabolism comprises the processes essential for life by which the complex substances in the body’s cells are built up or broken down. Encephalopathy is a general term that describes brain disease, damage, or malfunction usually related to inflammation within the body (Merriam-Webster, 2018). If we combine all these terms, a TME diagnosis would follow when toxic cells in the body do not allow the healthy breakdown of substances leading to inflammation of the brain cells. This can cause an altered mental status, changes with walking, and overall weakness and deconditioning. Delirium is another term you may hear for TME.

Is TME a brain injury?

Yes; it is a non-traumatic, acquired brain injury, or something that happens to the brain after birth. TME is debilitating for some, especially as we age, and may cause changes in physical and cognitive functioning. The causes of TME are numerous and varied. Some causes are infections, dehydration, malnutrition, alcohol toxicity, liver/kidney disease, metabolic imbalances, or reduced oxygen to the brain. If you have a pre-existing medical condition or if you’re not as active as you once were, you are more susceptible to developing TME. Researchers consider encephalopathy to be a symptom of an underlying condition, such as chronic urinary tract infections or uncontrolled diabetes. Therefore, if an encephalopathy is diagnosed, a pre-existing condition must also be addressed.

It is difficult to diagnosis TME because other issues have to be ruled out first. Rather than specific diagnostic testing, a combination of results from standard lab work and tests must be evaluated. Tests assess for infection, abnormal blood glucose levels, elevated ammonia levels, or changes with liver or kidney enzymes. A CT scan or MRI of the brain is used to rule out underlying neurological conditions or changes in your brain function. The results of these tests assist your physician in determining an accurate diagnosis.

Certain conditions lead to increased toxicity levels, increasing your risk of developing TME. Current or previous drug or alcohol abuse could lead to an imbalance in your metabolism, which can lead to an altered mental status. Additional causes of this type of imbalance are dehydration and malnutrition. When you drink water and consume nutrients, your body takes in a balanced amount of electrolytes, keeping the body’s cells nourished and functioning. When you are not drinking enough water, cells have a higher level of sodium, resulting in the metabolic imbalance. This leads to functional decline, an acute state of confusion, seizures, or death (Panther, 2016).“A diet rich in vitamins and minerals such as Folic Acid and Omega-3 fats prevents a cognitive decline as we age and decreases serious health risks” (Torres, et. al, 2012). Dehydration and malnutrition can lead to emergency care needs and hospitalization. With knowledge and recognition of symptoms, both are avoidable.

“Some medications can cause or exacerbate cognitive deficits and thus complicate rather than facilitate restoration of health. Use of anti-epileptic drugs to reduce seizures or cancer treatment drugs have been reported to cause delirium, reduced cognitive processing, or deficits with short term memory” (Youse, 2008). Medications that help the kidneys reduce sodium or water levels in the body can change the body’s chemical make-up and lead to dizziness and confusion. This is because the body is not breaking down the medications thoroughly, and that build-up of medications leads to toxicity. “The chances of a medication build-up increases especially in the elderly and with other medication interactions” (Abou-Khalil, 2015). It is important to review your current medications with your primary physician and pharmacist. Certain medications may have side effects or have interactions with other medications that cause symptoms of TME.

While there is no specific cure for TME, there are treatments for the underlying causes that may lead to an improvement in symptoms. For example, if your TME occurs because of an infection, you may notice your altered mental status improves and you have more energy to complete daily activities once you complete the course of antibiotics. If your sodium levels are too high because of dehydration, you will notice overall functional improvements once adequately hydrated. Underlying pre-existing conditions may prolong recovery time, and some changes and deficits may become permanent, especially as we age. Recovery might have to include adjusting how you complete routine activities.

If you are diagnosed with TME, your doctor may recommend a length of stay at a rehabilitation hospital to improve your physical or cognitive functioning. Physically, you may present with weakness and fatigue and changes with walking. This impacts your ability to complete everyday tasks such as getting in and out of bed, and increases your risk for falls. Physical and occupational therapies focus on improving strength, endurance, and balance. Therapists will educate you about compensatory strategies and will recommend necessary equipment to complete your daily activities safely. According to Gion (2013), those diagnosed with TME have a higher percentage of falls.Nearly all patients who have fallen in a hospital setting have had evidence of TME and are six times more likely to fall after they are discharged. Fall prevention and safety training through skilled therapy are key in minimizing a fall risk for yourself or a loved one.

Diagnosis of TME can impact cognition, or the everyday thinking skills that control areas such as memory, judgment and problem solving. Deficits in cognition can impact your ability to continue to live independently. For example, you may have difficulty following recipes for daily meals or organizing a daily pill schedule for medication management. Cognitive therapy at a rehabilitation center may be performed by neuropsychologists, speech-language pathologists, and occupational therapists. The focus is to improve mental skills and train compensatory strategies to improve functional daily activities.

Encephalopathy might not be fully preventable, but there are some general wellness tips that are recommended. Keep your mind active by completing your daily responsibilities and enrichment activities, such as word searches or jigsaw puzzles. As the saying goes, “If you don’t use it, you lose it.” You should also think about your nutrition. Eat the foods recommended to you by your doctor or dietician for a well-balanced diet, and make sure you’re well-hydrated to keep the cells of your body nourished. If you don’t like plain water, add some sliced fruit to give it flavor. Lastly, make sure you exercise within your means. If you can go for a walk, take it! If you can do chair yoga, do it! Exercise promotes a healthy lifestyle and keeps the body going, including getting oxygen and blood to all parts of the body – especially the brain!

References

1. Abou-Khalil, B., & Abou-Khalil, R. (2015). Seizure disorders and the effects of antiepileptic medications on cognitive-communicative function. Perspectives on Neurophysiology and Neurogenic Speech and Language Disorders, 25(2), 47. doi:10.1044/nnsld25.2.47
2. Dictionary by Merriam-Webster: America’s most-trusted online dictionary. (n.d.). Retrieved January 10, 2018, from https://www.merriam-webster.com/
3. Gion, T., & Leclaire-Thoma, A. (2013). Delirium in the brain-injured patient. Rehabilitation Nursing, 39(5), 232-239. doi:10.1002/rnj.128
4. Panther, K. (2016). Best practices for dehydration prevention. Perspectives of the ASHA Special Interest Groups, 1(13), 72. doi:10.1044/persp1.sig13.72
5. Torres, S., et al. (2012). Dietary patterns are associated with cognition among older people with mild cognitive impairment. Nutrients, 4(12), 1542-1551. doi:10.3390/nu4111542
6. Youse, K. M. (2008). Medications that exacerbate or induce cognitive-communication deficits. Perspectives on Neurophysiology and Neurogenic Speech and Language Disorders, 18(4), 137. doi:10.1044/nnsld18.4.137

Contributors: Jessica Heimall, DPT, CBIS, and Jared Burch, DPT.

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This article originally appeared in Volume 12, Issue 1 of THE Challenge! published in 2019.