Category Archives: Head

What You Need To Know About Frontal Sinus Fractures

Fracture of the frontal sinus is less common than other facial injuries, but can be more complex to deal with, both in the shorter and longer terms. These are generally high energy injuries, and facial impact in car crashes is the most common mechanism. Fists generally can’t cause the injury, but blunt objects like baseball bats can.

Here’s the normal anatomy:

sinus-fracture-treatment

 

Source: www.facialtraumamd.com

There are two “tables”, the anterior and the posterior. The anterior is covered with skin and a small amount of subcutaneous tissue. The posterior table is separated from the brain by the meninges.

Here’s an image of an open fracture involving both tables. Note the underlying pneumocephalus.

frontal_sinus1

A third of injuries violate the anterior table, and two thirds violate both. Posterior table fractures are very rare. A third of all patients will develop a CSF leak, typically from their nose.

These fractures may be (rarely) identified on physical exam if deformity and flattening is noted over the forehead. Most of the time, these patients undergo imaging for brain injury and the fracture is found incidentally. Once identified, go back and specifically look for a CSF leak. Clear fluid in the nose is, by definition, CSF. Don’t waste time on a beta-2 transferring (see below).

If a laceration is clearly visible over the fracture, or if a CSF leak was identified, notify your maxillofacial specialist immediately. If more than a little pneumocephalus is present, let your neurosurgeon know. Otherwise, your consults can wait until the next morning.

In general, these patients frequently require surgery for the fracture, either to restore cosmetic contours or to avoid mucocele formation. However, these are seldom needed urgently unless the fracture is an open fracture with contamination or there is a significant CSF leak. If in doubt, though, consult your specialist.

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Is Decompressive Craniectomy Any Better Than Craniotomy?

Severe TBI consists of a primary injury to the brain, followed by swelling, vascular, and ischemic problems which may cause a secondary injury. Much of the critical care management of this injury involves avoiding or ameliorating secondary injury. This is typically accomplished via medical means first, and through surgical procedures when medical management is insufficient.

Two types of surgical decompression are currently practiced: craniotomy and evacuation of blood/clot, and decompressive craniectomy with removal of a bone flap. The latter can be performed prophylactically before severe swelling occurs, or therapeutically as a damage control procedure when ICP is refractory to all other measures.

There has been a decades-old debate as to whether craniectomy, which is a major undertaking with months of skull/bone flap management, is actually worthwhile. Most studies have examined the utility of damage control craniectomy for refractory ICP. The results have not really been convincing one way or the other.

But what about prophylactic decompressive craniectomy (DC) to avoid future ICP problems while the patient is in the ICU? The surgical group at the University of Arizona at Tucson performed a five year retrospective review of their experience. Using propensity score matching, they identified 99 severe TBI patients who underwent DC (33) or craniotomy only (CO, 66). A power analysis showed that this sample size should be sufficient to demonstrate a significant difference.

Here are the factoids:

  • Both groups were similar with respect to age, GCS, ISS, AIS-head, and type of bleed
  • 26% died and 63% were discharged to rehab or skilled nursing facility
  • When comparing DC to CO groups, there were no differences in mortality, discharge to skilled nursing facility, discharge GCS or Glasgow Outcome Scale
  • There were more complications in the DC group, including shunt insertion for hydrocephalus (9% vs 0%), and reoperation (12% vs 2%)
  • Rates of wound infection and ventriculitis were the same for both groups (0-3%)

Bottom line: Although the study is small, it supposedly had enough patients for identification of significant differences. And basically, it didn’t show a positive difference for prophylactic decompressive craniectomy. There is certainly some opportunity for selection bias by the neurosurgeons that cannot be controlled for by this retrospective design. But it is yet another piece of the decompressive craniectomy puzzle. 

Overall, the literature support for either prophylactic or damage control craniectomy is not very strong. If it were, we would have identified some real benefits by now. What we don’t know is if there are specific subgroups of severe TBI patients who might benefit from it. So if your center is not involved in a project to study this, you should probably ask your neurosurgeons to base their practice only on what we know about this procedure to date. 

What Happens To Your Average Subarachnoid Hemorrhage?

Management of traumatic brain injury (TBI) is a common issue faced by trauma professionals. And isolated subarachnoid hemorrhage (SAH) is one of the more common presentations. In many centers, this diagnosis frequently results in admission to the hospital, neurosurgical consultation, and repeat imaging.

Is this too much care? We adopted a practice guideline nearly two years ago based on our own clinical experience that eliminated the last two. Patients were still admitted for neurologic monitoring for 16 hours. But is even this too much?

What we really need is a better understanding of the natural history of uncomplicated traumatic SAH. Well, a study from Sunnybrook and the University of Toronto does just that. They performed a 17 year meta-analysis of the literature on isolated SAH with mild TBI (GCS 13-15). They pared their initial literature search of nearly 2900 studies down to the usual few, 13 in this case. All but one were retrospective, of course, and they had the usual design flaws.

Here are the factoids:

  • How many patients eventually needed neurosurgical intervention?  0 (Well, almost zero. It was 0.0017%, to be exact.)
  • How many had progression of the SAH? About 6%
  • How many had neurologic deterioration? 0.75%, which included two  patients with increased headache and one with some confusion. Two developed intraparenchymal hemorrhage (one was on anticoagulants)
  • How many died? Only 1 died from neurologic causes, and that patient was anticoagulated at the time of injury.

Bottom line: It looks like we may be overdoing it for patients with isolated SAH and mild TBI. The natural history seems to be fairly benign, unless the patient is taking anticoagulants. The type of drug was not specified, so warfarin, aspirin, clopidogrel, and the newer anticoagulants should all be included.

Perhaps it’s time to update the our practice guidelines further. It looks like most of these simple, isolated SAH can be evaluated and released. However, if the GCS is 13 or 14, they should still be admitted for monitoring for a short period. And if on anticoagulants, admission with a repeat CT is in order.

Related posts:

Reference: The clinical significance of isolated traumatic subarachnoid hemorrhage in mild traumatic brain injury: A meta-analysis. J Trauma , published ahead of print, July 8 2017.

Tips For Taking Care Of CSF Leaks

The management of CSF leaks after trauma remains somewhat controversial. The literature is sparse, and generally consists of observational studies. However, some general guidelines are supported by large numbers of retrospectively reviewed patients.

  • Ensure that the patient actually has a CSF leak. In most patients, this is obvious because they have clear fluid leaking from ear or nose that was not present preinjury. Here are the options when the diagnosis is less obvious (i.e. serosanguinous drainage):
    • The “halo” or “double ring sign” is a form of pillow chromatography. The blood components separate from the CSF as they move through the pillow fabric, creating a clear ring or halo surrounding a bloody spot. This is the cheapest, fastest test and is actually fairly reliable.
    • High resolution images of the temporal bones and skull base. If an obvious breach is noted, especially if fluid is seen in the adjacent sinuses, then a CSF leak is extremely likely.
    • Glucose testing. CSF glucose is low compared to serum glucose.
    • Beta 2 transferrin assay. Don’t do it!! This marker is very specific to CSF. However, the test is expensive and results may take several days to a few weeks to receive. Most leaks will have closed before the results are available, making this a poor test.
  • Place the patient at bed rest with the head elevated. The basic concept is to decrease intracranial pressure, which in turn should decrease the rate of leakage. This same technique is used for management of mild ICP increases after head injury.
  • Consider prophylactic antibiotics carefully. The clinician must balance the likelihood of meningitis with the possibility of selecting resistant bacteria. If the likelihood of contamination is low and the patient is immunocompetent, antibiotics may not be needed.
  • Ear drops are probably not necessary. They may confuse the picture when gauging resolution of the CSF leak.
  • Wait. Most tramatic leaks will close spontaneously within 7-10 days. If it does not, a neurosurgeon or ENT surgeon should be consulted to consider surgical closure.

References:

  1. Brodie HA, Thompson TC. Management of complications from 820 temporal bone fractures. Am J Otol, 1997;18:188-197.
  2. Brodie HA. Prophylactic antibiotics for posttraumatic cerebrospinal fluid fistulas. Arch Otolaryngol Head, Neck Surg. 123:749-752.

Do We Really Need To Consult Neurosurgery For Mild TBI?

We consult our neurosurgeons too often. Think back on all the head injured patients you have admitted and placed a neurosurgical consult. How many times did they recommend something new or different, or take them to surgery? Not very often, I would guess.

This is becoming a hot topic. Check out the references below to read about a few other studies that have taken a similar approach.

The trauma group at Scripps Mercy in San Diego retrospectively reviewed their admissions to determine how often patients with mild TBI (GCS > 13) and some degree  intracranial hemorrhage required neurosurgical intervention, even if they were intoxicated or taking anti-platelet or anticoagulant drugs. A total of 500 patients were studied over a 28 month period.

Here are the factoids:

  • 49 (10%) of patients required some sort of neurosurgical intervention (41 craniotomy/craniectomy, 8 ICP monitors)
  • 93% of patients had neurosurgical consultation, and made additional recommendations in only 10 (2%),none of which changed management
  • There was no clinical difference in GCS between those who received an intervention and those who did not
  • Epidural and subdural hematomas were significant predictors of neurosurgical intervention
  • Intoxication or use of anti-platelet or anticoagulant drugs was not associated with intervention. These were present in 30% of all patients!
  • Unsurprisingly, ICU and hospital length of stay were longer in patient who underwent an intervention

Bottom line: As I said, this seems to be a hot research topic. And in this study, the numbers are getting larger and the criteria more inclusive (alcohol and anticoagulants allowed).

Neurosurgeons play a very important role in patients with more moderate to injury to their brain, and with spine injuries. But their input may not be needed in many patients with milder injuries. These data suggest that, in patients with GCS > 13, only subdural and epidural hematomas require consultation because they are much more likely to require intervention. 

This parallels a practice guideline we have in place where patients with subarachnoid or small intraparenchymal hemorrhage, or a linear skull fracture are managed by the trauma service without neurosurgical consultation. We do involve them if there is any intracranial hemorrhage with a history of anticoagulant use, however.

We all need to use our neurosurgeons wisely, and this paper helps to clarify situations where they may and may not be needed. 

Related posts:

Reference: Routine neurosurgical consultation is not necessary in mild blunt traumatic brain injury. J Trauma 82(4):776-780, 2017