A new study published today explains why some women with epilepsy start experiencing breakthrough seizures after conception.

The study results, which were gathered as part of Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD), demonstrate why some women with epilepsy begin having breakthrough seizures after conception, reinforcing the need to increase antiseizure medication doses and closely monitor blood levels throughout pregnancy.

Some people believe that changes in drug concentrations in the blood do not occur until after 20 weeks of pregnancy, but this research illustrates how critical it is to begin monitoring and changing patients’ medication dosages as soon as possible.

Epilepsy is a life-altering neurological illness that affects both children and adults, with no known cause in two-thirds of cases. Nerve cells in the brain of patients with epilepsy are hyper-reactive, leading them to shift their electrical activity pattern and become spontaneously active, millions of cells at a time. Seizures, which cause a person to become disoriented, lose consciousness, and, in some situations, experience limb movements or rigidity, are a result of synchronous activation in patients with epilepsy.

Epilepsy treatment has had a tumultuous medical history, exacerbated by centuries of beliefs and stigma. Many people who have epilepsy go undetected or receive inadequate treatment. Despite the fact that drugs may often effectively control epileptic seizures, the first-generation therapies had a host of harmful side effects and were not recommended for those who were attempting to conceive.

Since then, safer drugs have entered the market and been more readily available in the United States, but clinicians have begun to notice a new problem: people with epilepsy who had been successfully controlled with medications began having seizures shortly after getting pregnant.

“Identifying which antiseizure medications may have changes in concentrations and at what point in pregnancy those changes occur is important for determining which patients may need to be monitored more closely during pregnancy and after delivery,” says senior author Angela Birnbaum.

Pennell and colleagues set out to solve the puzzle by analyzing blood concentrations of ten regularly used antiseizure medicines and comparing them across different phases of pregnancy and after childbirth.

The researchers discovered that blood levels of seven out of ten of the drugs they looked at declined considerably, ranging from 29.7 percent for lacosamide, a popular anticonvulsant, to 56.4 percent for lamotrigine.

Furthermore, the researchers found that the decline in drug content in the blood happened within days after conception, well before most women had their first prenatal appointment and the pregnancy manifested itself physically.

“Until now, we knew very little about how becoming pregnant impacted blood levels of most anti-epileptic medications,” adds Vicky Whittemore, Ph.D., program director at the National Institute of Neurological Disorders and Stroke (NINDS). “This study lays the groundwork for a larger goal of the MONEAD study, which is to improve outcomes in women with epilepsy by better managing their medications over the course of pregnancy.”

Source: 10.1001/jamaneurol.2021.5487

Image Credit: Getty

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