Children born to mothers with rheumatoid arthritis (RA) are at increased risk for developing epilepsy, new research shows.
The study, “Parental rheumatoid arthritis and childhood epilepsy,” published in the journal Neurology, showed that children born to mothers with RA were 26 percent more likely to have epilepsy than children who had moms without the condition. Children of fathers with RA did not appear to be at greater risk for developing epilepsy.
Epilepsy is a neurological disorder characterized by recurrent epileptic seizures, often of unknown cause. Likewise, the cause of RA, a disease that affects more than 1.3 million adults, is also unknown. The causative factors in both epilepsy and RA can include family history, genetics, environmental factors, trauma, and lifestyle.
To assess the influence of parental RA on the risk of epilepsy, Ane Lilleore Rom, PhD, of Copenhagen University Hospital in Denmark, and colleagues conducted a nationwide cohort study of all children born in Denmark from 1977 to 2008 (1,917,723 children).
All children were followed for an average of 16 years. Of those, 31,491 children (1.6 percent) developed epilepsy. A total of 13,556 children (0.7 percent) had mothers with RA. This included mothers who had the condition when the child was born, as well as those who were diagnosed with RA after their child’s birth.
The researchers found that compared to unexposed children, children whose mothers had RA at the time they were born had up to a 90 percent increased risk of developing epilepsy, while children whose mothers had preclinical RA had a 26 percent increased risk of developing epilepsy.
In absolute numbers, it means that 2 percent of children from mothers with RA, and 3 percent of children whose mothers had preclinical RA, later developed epilepsy.
The results remained the same after researchers adjusted for the baby’s birth weight, gestational age at birth, and mother’s epilepsy.
“These results suggest that changes in the environment for the fetus may play a role in the development of epilepsy,” Rom said in a news release. “We don’t know yet how this may work, but it could involve the production of maternal antibodies that could affect the unborn child.”
According to Rom, since children of mothers with preclinical RA were also at increased risk for developing epilepsy, the results indicate that RA itself plays an important role in epilepsy, rather than the potential effects of drugs to treat RA. However, the influence of RA drugs on the risk of epilepsy needs to be further investigated.
Evidence from studies has shown that there is a link between autoimmune diseases involving the brain, such as multiple sclerosis, and an increased risk of epilepsy. Other studies have also shown that RA increases the risk for developing epilepsy, even though the condition does not directly affect the brain.
“But it is new knowledge that also offspring of mothers with rheumatoid arthritis seem to have an increased risk of developing epilepsy,” Rom said.