Two “head problems,” two differentials

 

The night has been steady. You appear to be in a lull between local infection outbreaks. You just sent the resident down the hall to investigate an 11-day-old with the complaint “problem with his head”. Man, that could be anything. You scan the vital signs in the computer and they look alright. You decide to await events.

 

Soon enough the resident comes out and finds you. The story she presents goes like this: The baby is a full-term, 11 day-old from an uneventful pregnancy, labor and delivery. He has so far led a blameless life until this afternoon when his mother was holding him while she walked through a doorway. She says she accidentally brushed his head against the door frame. Not hard, she insists, the infant didn’t even cry. He’s been acting normally since. However, this evening she felt the back of his head and noticed a bump there that didn’t feel right to her. She remembered the door frame incident and decided he needed to be checked. He has been feeding well, has not been vomiting, has not been unusually sleepy or irritable. If it weren’t for the bump, she wouldn’t have brought him. The exam reveals and healthy and vigorous baby boy. He does indeed have a bony prominence palpable in the left post parietal-occipital region. The rest of his exam, including the newborn neuro exam (tone, grasp, suck, reflexes, and equal movement of all four extremities) is normal.

So, do you get a head CT? Incurred a head bump, has a head bump, gotta image him, right? Well, not so fast. The location of the head bump corresponds to the lambdoidal suture line. You go into the room, confirm that the baby looks great, and palpate the head carefully. Yep – the infant has a matching bump on the right corresponding to the other suture, it’s just a little more prominent on the left than on the right. The diagnosis: over-riding sutures. This is due to movement of the plates of the flexible infant skull as it comes through the birth canal. It is benign and will slowly resolve over the weeks after birth. You can find “bumps” in normal newborn skulls any place that anatomically corresponds to a suture line. You reassure the mother and send them home.

An hour later the nurse puts another infant in the same room with practically the same complaint. Another “problem with his head”. Again the vitals look fine. Off goes the resident. Back comes the story.

This infant is a 6-month-old. He was a preemie and a twin and had some early lung disease but is now doing fine. Tonight his mother noticed that his fontanelle seemed full. She has some medical knowledge and knew that this could be a problem so she brought him in. He has had no fevers or symptoms of illness. He has not been vomiting. In fact, he’s acting just fine.

On further questioning, you establish that he was a 28-week preemie. Infants that come that early are prone to head bleeds in the developing germinal matrix, which can subsequently lead to hydrocephalus. These bleeds are screened for with head ultrasounds through the open fontanelle, while the babies are still in the hospital. You ask about this and the mother tells you that the baby had two head ultrasounds, both negative for bleeds.

On exam, the infant is interactive and appropriate for corrected age (remember, if he was born three months early he won’t necessarily behave like a six-month-old, more like a three-month-old). He does have a very full fontanelle, but it is not tense or bulging. There are no other abnormalities to the skull. His extra-ocular motions are intact and his pupils are equal. The rest of this infants’s exam is completely normal. He looks great.

So what’s with this kid? Does he need an LP to r/o meningitis? No, there’s nothing here to suggest a serious infection. Does he need a head CT? Yes, because your differential includes hydrocephalus (despite the normal head ultrasounds) and also nonaccidental trauma. So you order a noncontrast head CT and wait for the results.

The head CT results come back (pictured). The infant’s ventricles are not enlarged and there is no evidence of trauma. There is some extraaxial fluid in the subarachnoid space. The Neurosurgery resident is paged and comes down to render his opinion. This is not likely hydrocephalus, given the normal-appearing ventricles. This is most likely benign extraaxial fluid of infancy.

Benign extraaxial fluid of infancy refers to an abnormal accumulation of CSF in the subarachnoid space. It does not produce symptoms or obstruction and is normally re-absorbed by the age of 18-24 months. These should be referred to Neurosurgery and the patients should get periodic follow-up scans to document that the fluid is indeed being re-absorbed.

So, two heads, two developmental variants, both benign. And two more items for your differential when you consider babies with “head problems”.

Amy Levine, MD, is an assistant professor of pediatric EM at UNC Chapel Hill

Keep it under wraps | Casting a terrible two

You’ve just examined a cute little blonde mop-top who is two years old and who fell off the bed, injuring her left elbow. X-rays confirm she has a small, nondisplaced supracondylar fracture. You know, the kind you can splint yourself. No problem, right?

You approach moppet with plaster in your hands, and the battle begins. She is not happy about this splint and she’s not going to take this one lying down. With the help of the nurse and a rather dazed medical student (who has probably just decided he is not going into pediatrics) you apply a double sugar tong to the little girl’s left arm. Is the job done? Yeah right. Your job is not just to get the splint onto a reluctant arm, but also to keep it there. Blondie has battle in her eyes–you know that as soon as you walk away she’ll do her best to tear off your handiwork. Luckily you have a few tricks up your sleeve.

For the time being you take a large ace wrap and bind the arm to the child’s chest. You then put her shirt on over this, placing two barriers between your outraged patient and her splint. Finally, you whip out a popsicle to distract Goldilocks from her mission to free her left arm. Fortunately, it works.
When Mom gets home she is advised to continue putting a shirt over the arm. A large onesie, or similar type one-piece garment that snaps in the crotch, works quite nicely. It usually allows the mother to be able to discontinue the ace wrap so she can monitor the splint better and make sure the child’s fingers remain pink and wiggly.

I told the mother that if the child removed the splint to return to the ED. My system must have worked however, because she didn’t come back. Phew!

~Dr. Levine