Early observation can help kids with this rare birth defect grow and develop normally.
by Featured Provider Nicholas Wetjen on Monday, November 2, 2020
Tiny rolls and dimples are part of what makes babies so darn cute. As your bond with your baby grows, you get to know all the dimples, freckles and spots that make your little one unique. You’re so in tune with your child’s every quirk that you can catch when something’s different right away.
Occasionally, there’s something that’s been right in front of your eyes the whole time. But since your baby was born with it, you never knew it was problematic until other symptoms showed up.
It’s called a sacral dimple — a possible sign of a congenital condition.
Does your baby have a small dent in their lower back, just above their tush? Up to eight percent of babies are born with this skin defect. Most of the time, it’s meaningless — one of those little dimples you coo over as you change diapers.
In rare cases, it’s a surface-level sign of an underlying spinal condition called tethered cord syndrome.
“In some babies, the bottom part of the spinal cord doesn’t form properly and ends up being attached to the bottom of the spinal column, either by a thickened band or large lump of fat,” explains Nicholas M. Wetjen, MD, a pediatric neurosurgeon at The Iowa Clinic. “But usually there are clues on the skin — either a dimple, discoloration, very thin skin or a track above the gluteal cleft — that might be an indication that there’s an abnormality on the spine.”
Your Child's Health Is Our #1 Priority, Too
Trust Central Iowa's most experienced pediatric neurosurgeon, Dr. Nicholas Wetjen.
Meet Dr. Wetjen ►
Other tethered cord symptoms aren’t noticeable until later in life.
As a child grows, their spine grows. When part of the spinal cord is stuck in place, the cord slowly stretches as a baby gets bigger. This damages the cord and the nerves around it, which hurts development and presents neurologic issues.
“There can be a number of neurologic issues. You could see a weak foot or foot deformity, delayed walking, bowel issues or back pain in older kids. Bladder dysfunction, in particular, is common. Those all might indicate there’s a tethered cord,” Wetjen says.
Children hit developmental milestones as they grow, whether it’s learning to walk or potty training. You may never notice anything is wrong until they fall behind the typical child development timeline.
Diagnosing tethered cord syndrome often relies on symptoms like these to appear. But the condition can stay hidden for years if it’s asymptomatic. Children typically don’t show symptoms in the first year or two, Dr. Wetjen says. They’re more likely to occur in toddlers or school-age children.
Older children and even adults may find they have tethered cords when undergoing diagnostic imaging after an accident or injury. Or they start experiencing unexplainable leg weakness or back pain that worsens with activity.
“It’s not as common to find it in teenagers. And usually, it’s a less complicated case,” says Dr. Wetjen. “But they’ve had a tethered cord their whole life and, for whatever reason, were able to accommodate it until they got older. And then they developed symptoms.”
“There’s probably some unknown percentage of adults that have never developed symptoms and we just don’t know who they are.”
Detethering the spinal cord resolves, or prevents, symptoms.
Nobody wants to put their young baby through surgery. But the spinal cord doesn’t untether over time and the neurological issues cannot be fixed if you don’t go to the source of the problem. The earlier you treat the issue, the smaller the chance for permanent neurological deficit.
“If a child has symptoms, they should be treated right away. If they’re asymptomatic, you can decide to intervene early or wait for symptoms to develop,” Dr. Wetjen says.
He prefers to treat infants with tethered cord syndrome early — even if they show no symptoms. That often means he’s performing surgery to detether the spinal cord of babies well before their first birthday.
“It’s very difficult to identify some of these abnormalities in a baby. Younger babies are often diagnosed with a tethered cord through ultrasound or MRI,” Dr. Wetjen says. “But you want to get a diagnosis early — within the first six months — so you can monitor the baby and have a discussion about the best way to approach the problem.”
Some tethered cords are more complicated than others and there may be a risk that detethering surgery will bring on symptoms that were not there before. Waiting is also a risk.
Every situation is different. The cord can be tethered in all sorts of ways. That’s why Dr. Wetjen recommends discussing the pros, cons and timing of tethered cord surgery with your pediatric neurosurgeon so you can make an individualized and informed decision.
“There’s always a possibility a child may never develop symptoms and that surgery, theoretically, would be completely necessary. But the risk of surgery is really low. The potential complications aren’t irreversible, they’re treatable. Whereas, if a child develops symptoms late, it could be too late to correct them,” he says.
“There’s some nuance to the decision-making. So there needs to be a fair and balanced discussion about whether to operate early or wait until your child develops symptoms.”