Metabolism is the chemical reaction in the body’s cells that changes food into energy. It’s a complex process that involves many different enzymes and proteins. If there are mutations on the genes that code for these proteins or enzymes, the metabolic process can go wrong and cause problems known as metabolic disorders (also called inborn disorders of metabolism).
Metabolic disorders have been linked to epileptic seizures. It’s important to know if seizures are caused by a metabolic disorder because it may be possible to stop the seizures by treating the metabolic disorder. Although some metabolic disorders may be diagnosed during routine newborn screening, others may only be identified later on in childhood, adolescence, or even adulthood if someone develops symptoms.
Genetic mutations that cause metabolic disorders tend to be passed from one generation to the next (inherited).
Gaucher disease is one example of a metabolic disorder marked by seizures. Gaucher disease is a genetic disorder caused by mutations in the GBA gene. For someone to have Gaucher disease, they must receive mutated genes from both parents. Gaucher disease causes problems with lipid (fat) metabolism, resulting in lipids building up in organs.
Our bodies are so sensitive to changes in metabolism that problems with just one of these enzymes or proteins can be disastrous.
There are a few ways in which metabolic disorders can cause seizures. For example, these disorders can:
Because a breakdown of metabolic processes can directly lead to epilepsy, it is important to recognize the metabolic disorder and treat it to reduce (or even eliminate) seizures.
The International League Against Epilepsy recognizes several different types of metabolic epilepsies:
Each of these metabolic disorders has unique genetic causes and associated symptoms, but they all cause seizures.
Biotinidase deficiency and holocarboxylase synthetase deficiency are both inherited disorders that affect the way the body processes a vitamin called biotin (vitamin H). Biotin is a very important vitamin needed to break down protein, lipids, and carbohydrates.
Biotinidase deficiency is associated with muscle weakness, problems controlling body movements, developmental delay, and issues with vision and hearing. Holocarboxylase synthetase deficiency is associated with poor appetite, vomiting, lethargy, irritability, muscle weakness, and skin problems.
These diseases are also known to cause seizures. In both disorders, biotin supplementation has been shown to reverse seizure activity.
In people with a cerebral folate deficiency, a lack of vitamin B folate (vitamin B9) in the brain results in degeneration of the nervous system. The folate deficiency is caused by dysfunctions in the protein needed to activate it.
This disease causes slow head growth, poor muscle tone, impaired balance and movement, muscle spasticity, speech difficulties, and epilepsy.
Creatine is a compound that is vital for energy metabolism in the cells. Creatine disorders include several conditions in which the production and transport of creatine are disrupted. Signs of creatine malfunctions include intellectual disability, muscle weakness, autism or behavioral problems, and seizures.
Folinic acid-responsive seizures and pyridoxine-dependent epilepsy both refer to rare epileptic brain disorders in newborns. Folinic acid-responsive seizures are related to vitamin B12, and pyridoxine-dependent epilepsy is related to vitamin B6. Both of these disorders are characterized in newborns by periods of irritability, unusual eye and facial movements, fluctuating tone, and poor feeding before seizures develop.
Glucose is a simple sugar that acts as fuel in the body. Glucose transporter type 1 deficiency is caused by a genetic mutation that results in a shortage of brain glucose. This condition causes cognitive impairment, microcephaly, epilepsy, and movement disorders.
Mitochondria are called the powerhouses of cells because they are responsible for energy production. Mitochondrial disorders result when mitochondria are affected by genetic mutations.
Mitochondrial disorders are the most common group of inherited metabolic disorders. Mitochondria are found in every cell of the body except red blood cells, so disease of the mitochondria can affect nearly every part of the body, including the brain.
Peroxisomes are cellular organs that help to process fatty acids and amino acids. Peroxisomal disorders refer to diseases that affect peroxisomes. Symptoms of these disorders include hearing and vision loss, reduced muscle tone, neurological issues, developmental delays, feeding issues, seizures, and liver, kidney, and bone disease.
Other metabolic disorders associated with epilepsy include:
Metabolic disorders can be treated in many ways. In some cases, specific vitamins and essential nutrients can replace what’s missing in the body. For instance, research shows that biotin, creatine, pyridoxine, and folinic acid can all be used to treat conditions in which that respective nutrient is missing. In other cases, medication may be prescribed to help manage the disorder.
Lifestyle changes may be able to help, too. For example, ketogenic diets have been shown to help manage glucose transporter type 1 deficiency. Read more here about the ketogenic diet.
MyEpilepsyTeam is the social network for people with epilepsy. On MyEpilepsyTeam, more than 105,000 members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.
Are your seizures caused by a metabolic disorder? Share your experience in the comments below, or start a conversation by posting on MyEpilepsyTeam.