Denouement: Fall on Head and Bradycardia

by Lauren Staple with Moh Saidinejaid on the Hot Seat

This is a case of an 8 year-old girl who had a low mechanism head injury, a sore neck, and normal neurological exam who developed bradycardia and was found to have a dens fracture on neck CT. For the complete case presentation, click here.

Thank you to Sabah, Dave, Behnaz, Paul, Jamil, Dipak, and Theresa who commented on this case and for the lively discussion. Click here and scroll up to see the insightful discussion.

Here is how you answered our questions:

Given the CT finding, what is your NEXT step?

No one wanted to call a trauma stat for a full trauma evaluation. Other comments:

• "Consult neurosurgery to discuss fracture management."
• "I would consult both NSU + ortho as they have a combined spine service. "
• "This patient with dens fravcture and now has drop in HR and is well perfused is in spinal shock (neurogenic shock). He will soon if not alreday hypotensive. He needs boluses of fluid and norepinephirine drip if not improved in trauma room with all c spine trauma precaution." 

What does this EKG show?

One person said, "Third degree heart block."
What is your most important next step?

Comments included, "Hemodynamically stable. Probably not related to the c-spine injury" and "not symptomatic, send labs."

The Hot Seat Response
by Moh Saidinejaid
Thanks Lauren, for an interesting and challenging case, and thanks to all others who posted responses.

This is an 8 year-old female who suffered a neck injury after losing her balance while doing head stands. The tenderness over the C1-C2 spine and the CT finding of a type I dens fracture suggest neck hyperflexion as the mechanism of this injury. She complains of a headache, but her exam is otherwise unremarkable. Additional information includes bradycardia to 40s on the monitor during her ED course.

Type 1 dens fracture (fracture through the superior aspect or tip of the dens), is the least unstable, but it can still be associated with significant ligamentous injury. I am not completely sure about what to make of the resolved neonatal issues as they relate to this case. In my opinion, the heart block is likely unrelated to the injury.

Differential diagnosis for the bradycardia: 
Traumatic brain injury with possible uncal herniation with c-spine injury: This may be considered given the headache (concussion?) and progression to bradycardia. The patient, however, is not displaying the hypertension and irregular respiration. The otherwise normal exam, the lack of LOC history, and the normal mental status, also makes this not entirely likely.

Simple vasovagal syncope versus seizure activity preceding the neck injury: This is always on the differential, and may also be related to her heart block.

Neurogenic shock: Given the mechanism of injury, disruption of the spinal cord anatomical pathways may be a consideration, especially if the atlanto-axial ligamentous injury is suspected. Bradycardia, secondary to unopposed vagal tone, and subsequent hypotension, related to decreased systemic vascular resistance and pooling of blood in the extremities. May be a progression of this. With a type I dens fracture, the spinal cord disruption is generally expected to be less.

Spinal shock: This type of non-circulatory shock is less likely, again, given the nature of the dens fracture, which makes a transection of the cord less likely. It should be considered in the differential diagnosis, however, given the neck hyperflexion severe enough to cause a dens fracture. I don’t think this patient is in spinal shock, given lack of any sensory or motor deficits. Also, the type I dens fracture makes a complete spinal cord injury, leading to spinal shock less likely.

A primary cardiac etiology unrelated to the neck injury: Given the second degree heart block (Mobitz type1, a.k.a. Wenckebach), some sort of traumatic cardiac injury versus undetected baseline heart block should be considered as well.

Management:
This patient has a serious traumatic injury mechanism, and should be considered at risk for further neurologic deterioration. In terms of what to do next, I don’t think we need to get a trauma alert called, but given our resources and challenges in coordinating various sub-specialties (Trauma surgery, orthopedics, and neurosurgery), I would ask for a trauma alert anyway. Atropine can be a treatment option for heart block and bradycardia from neurogenic shock. I am not quite ready for atropine, because of the good circulatory status. If BP starts dropping more, dopamine or norepinephrine is on my agenda.

So, this is what I would do: (very frequent monitoring of vitals)
- Trauma alert now in the ED. (With PICU)
- Rigid collar
- Bring patient to the code bay.
- Full CR monitor, and have trauma evaluation.
- Detailed neurologic exam
- Neurosurgery and orthopedics (Dens fracture), CICU consult for heart block
- Move this patient to PICU ASAP. I don’t think I need to intubate or start atropine right now, but these are both something I need to consider later.
- I would do a non-contrast head CT
- Basic trauma labs including a CBC.
- I would love to have an MRI of the c-spine when possible

The Denouement
by Lauren Staple

The patient had an emergent non-contrast head CT done in the ED which was negative for intracranial injury. Trauma surgery, Neurosurgery and Cardiology were all consulted in the ED from D side, and the patient was admitted to the PICU for close monitoring given the sequence of events.

The patient’s perfusion and vital signs remained stable before transfer to the PICU (T 35.8, HR 55, RR 17, and BP 99/70). Detailed neuro exam remained unchanged. 

The EKG was read as SINUS RHYTHM WITH MOBITZ I (WENKEBACH) BLOCK. Cardiology said it could be due to increased vagal tone secondary to trauma and did not specify any need for follow-up.

She had an MRI of her brain and C-spine without contrast the following day which showed encephalomalacia along the posterior left sylvian fissure consistent with an old infarct and a thyroglossal duct cyst at the level of the hyoid bone.  No new hemorrhage, mass lesion or acute infarct. Both the MRI of the cervical spine and the CT of the cervical spine were read as NORMAL by the attending radiologist with no type I dens fracture, and the patient was discharged home that afternoon without a Miami J C-collar.

FASCINATING CASE!!

The Hot Seat is a recurrent online case series aimed at facilitating asynchronous sharing of PEM knowledge and experience. Faculty are placed on The Hot Seat and publish their opinions without knowing the case or its outcomes. Cases are all actual cases and are written by PEM fellows at Children's National in Washington, DC. Emily Willner is the faculty advisor on case presentations. Come back again for the next case in our series and we welcome your commentary.