Novel Approach Fusing Top Neck Vertebrae Shows Promise in Bow Hunter Syndrome

Recently published research suggests that fusing the neck’s top 2 vertebrae—in a novel procedure called C1C2 posterior fusion—is safe and effective for preventing strokes in pediatric patients with bow hunter syndrome.

The findings, appearing in Child’s Nervous System, detail the researchers’ ability to prevent strokes in 11 patients ranging in ages from 18 months to 15 years.

"Strokes in children are exceedingly rare, and those caused by bow hunter syndrome are even rarer," explained Bruno P. Braga, MD, assistant professor of neurological surgery and pediatrics at UT Southwestern Medical Center and an attending physician at Children’s Health, in a statement. "Because this condition is so uncommon, it is often underdiagnosed. In addition, the best way to treat it and prevent subsequent strokes has been unknown."

In patients with bow hunter syndrome, turning the head compresses blood vessels supplying the back of the brain from the vertebral artery. In pediatric patients, the cause of the condition is often not clear and typically is not discovered until there is a tear in the vertebral artery, causing the spilling of blood clots and subsequently leading to stroke.

All of the patients in the study had received a diagnosis of stroke—based on their presentation of a combination of neurological symptoms like vomiting, headache, and dizziness—between September 2014 and July 2020. The researchers were able to identify a tear in the vertebral artery (V3) located at the top of the neck as the cause for the strokes.

In the new approach, researchers fused the top 2 vertebrae with 2 screws, which proved successful in all of the children. According to the researchers, there was minimal blood loss (just 57.7 mL), no blood vessel or neurological injuries, and just 1 postsurgical complication—a superficial wound infection that was treated with oral antibiotics. After approximately 5 years of follow-up (with a mean follow-up of 33.3 months), no patient had experienced a repeat stroke.

"Avoiding a second stroke is infinitely better than treating a second stroke," said Braga. "Our new protocol could offer a lasting way to prevent pediatric bow hunter syndrome patients from a further devastating neurological event."

Treating a second stroke often becomes a reality, as children with this type of stroke—caused by a tear in the vertebral artery—are given the standard treatment consisting of a neck brace and anticlotting drugs in the absence of further investigation into its cause.

For each of the patients included in the study, the researchers tested the children after 3 months to see if the tear was caused by bow hunter syndrome. They used a dynamic angiogram, which showed that as patients turned their heads gently from side to side, there was compression in 1 or both of the vertebral arteries at the site of the previous tear, a defining feature of the syndrome.

Notably, the researchers identified a specific segment and configuration of the vertebral artery highly suggestive of the disease.

Reference

Braga B, Sillero R, Pereira R, et al. Dynamic compression in vertebral artery dissection in children: apropos of a new protocol. Child’s Nerv Syst. Published online November 6, 2020. doi:10.1007/s00381-020-04956-1