Surgical Anesthesia in Young Children Linked to Effects on IQ and Brain Structure

According to a study published in the journal Pediatrics, children who received general anesthesia for surgery before age 4 had diminished language comprehension, lower IQ and decreased gray matter density in posterior regions of their brain.

These findings were reported in the June edition from researchers at Cincinnati Children’s Hospital Medical Center. The team say this knowledge could make it possible to develop mitigating strategies for what the authors describe as a potential dilemma for child health, and recommend additional studies to determine anesthesia’s precise molecular effects on the brain, and contribution to diminished brain function and composition.

Andreas Loeppke, MD, PhD, FAAP and lead author of the study stated that “he ultimate goal of our laboratory and clinical research is to improve safety and outcomes in young children who have no choice but to undergo surgery with anesthesia to treat their serious health concerns.”

Loepke and his colleagues have published previous studies showing widespread cell death, permanent deletion of neurons and neurocognitive impairment in laboratory rats and mice after exposure to general anesthesia. These studies have raised concerns about similar effects in young children during a particularly sensitive neurodevelopmental period in early life, which researchers say could interfere with the refinement of neuronal networks and lead to long­term functional abnormalities.

In this study, Loeppke and his colleagues compared the scores of 53 healthy participants of a language development study (ages 5 to 18 years with no history of surgery) with the scores of 53 children in the same age range who had undergone surgery before the age of 4.

According to the researchers, the average test scores for all 106 children in the study were within population norms regardless of surgical history. However, children exposed to anesthesia scored significantly lower in listening comprehension and performance IQ compared with children who had not undergone surgery. The researchers also report that decreased language and IQ scores were associated with lower gray matter density in the occipital cortex and cerebellum of the brain.

By using extensive analysis of surgical and other medical records the researchers were able to match the children for age, gender, handedness and socioeconomic status – all confounding factors of cognition and brain structure. The types of surgeries and length of exposure to anesthetics were also factored in and the anesthetics used during the surgeries included common agents such as sevoflurane, isoflurane or halothane (used alone or in combination) and nitrous oxide.

Brain structural comparisons were conducted by MRI scans. and the children included in the study did not have a history of neurologic or psychological illness, head trauma or any other associated conditions. Neurocognitive assessments included the Oral and Written Language Scales and the Wechsler Intelligence Scale.

Loeppke and his team’s current study estimates that of the 6 million children who undergo surgery in the United States each year could experience a loss in the potential loss of 5 or 6 IQ,and that the lifetime potential earnings loss could total $540 billion. Previous research from 2008 had estimated the loss of 1 IQ point to decrease a person’s lifetime earnings potential by $18,000.

He and his team advise parents who are concerned to discuss with their pediatrician and surgeon the risks of a surgical procedure – and the potential risk of anesthetic exposure – versus the risks of not having a surgery, and insists that current methods are still very safe.

“It is important to note that no surgeries are truly elective in young children,” Loepke says.

“Many surgical procedures early in life treat life­threatening conditions, avert serious health complications, or improve quality of life. These cannot be easily postponed or avoided.”

He also stressed that researchers at Cincinnati Children’s are actively looking for alternative anesthetic techniques in their ongoing laboratory studies, and that there is ongoing research into drugs are being tested that show potential for lessening the harmful effects of anesthetics in laboratory rats and mice. Additionally, the medical center is participating in an international clinical trial to test an alternative anesthetic regimen in young children undergoing urological procedures.