Tag Archives: TBI

Could There Be A Simpler GCS?

The Glasgow Coma Scale (GCS) has been around forever. Or really, for about 45 years. It was actually developed in the early 1970s and known as the Coma Index. It was further refined into the GCS, when 1 was selected as the minimum component score. Ever since, it has been used as a common language among clinicians to communicate gross neurologic function and trends.

But it is still somewhat complicated. Oh no it’s not, you say? Then why do so many trauma resuscitation rooms have it posted on the wall? There are three components, each with a different number of possible values. And frankly, some are harder to remember than others. Decerebrate vs decorticate, right?

So what if someone told you that a single GCS component works just about as well as the whole bunch? Researchers have been piecing this together for years, focusing on the motor component of GCS (mGCS). There are two flavors of simplified score: mGCS and Simplified Motor Score (SMS). The mGCS is just what it sounds like: the full motor component of GCS, ranging from 1-6. The SMS is further simplified from the mGCS: mGCS of 1-4 tranlsates to SMS 0, mGCS 5 = SMS 1, and mGCS 6 = SMS 2. In my opinion, this is actually more complicated because you have to remember not only the 6 mGCS levels, but also the cutoffs to convert it to SMS.

Finally, a group from Oregon Health Sciences University in Portland performed a nice meta-analysis of the best individual studies.

Here are the factoids:

  • Only papers that compared total GCS (tGCS) to mGCS or SMS were included, and only if they analyzed a receiving operator characteristic curve. The statistics appeared sound.
  • tGCS was very slightly better than either mGCS or SMS at predicting:
    • in-hospital mortality
    • neurosurgical intervention
    • emergency intubation
    • severe TBI

Bottom line: Overall, the total GCS is slightly (just a few percent) better at doing the things listed above, compared to the motor score alone or the “simplified” (really?) motor score. Is this clinically significant in the field? Probably not. And its mere simplicity makes it appealing. 

However, there is one major problem to adopting the mGCS for use outside the hospital. Inertia. As I mentioned, we have been using the full GCS score for almost 50 years. Pretty much every trauma professional is familiar with the GCS or knows where to look up the details. But I suspect that those clincicians who assume care of the patient once in the hospital, and especially the intensive care unit (neurosurgeons) will never allow the use of an abbreviated scale. Good idea, but sorry, it won’t catch on in the real world.

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

Diagnostic Tip: Nail Discoloration After Severe TBI

Occasionally, patients who have had a severe brain injury but recovered relatively quickly may present with complaints of odd nail discoloration. This may involve fingernails and/or toenails. What gives?

This is actually a byproduct of repeated exams to determine the Glasgow Coma Scale score. A common way to determine the motor component is to squeeze the fingertip or toetip. I’ve seen some neurosurgeons use a pen to apply a great deal of force to the nail.

The discoloration is a resolving subungual hematoma. You may see different colors under different nails, depending on the age of the hematoma. Amaze your colleagues with your knowledge on this one!

Everything You Wanted To Know About: Cranial Bone Flaps

Patients with severe TBI frequently undergo surgical procedures to remove clot or decompress the brain. Most of the time, they undergo a craniotomy, in which a bone flap is raised temporarily and then replaced at the end of the procedure.

But in decompressive surgery, the bone flap cannot be replaced because doing so may increase intracranial pressure. What to do with it?

There are four options:

  1. The piece of bone can buried in the subcutaneous tissue of the abdominal wall. The advantage is that it can’t get lost. Cosmetically, it looks odd, but so does having a bone flap missing from the side of your head. And this technique can’t be used as easily if the patient has had prior abdominal surgery.

2. Some centers have buried the flap in the subgaleal tissues of the scalp on the opposite side of the skull. The few papers on this technique demonstrated a low infection rate. The advantage is that only one surgical field is necessary at the time the flap is replaced. However, the cosmetic disadvantage before the flap is replaced is much more pronounced.

3. Most commonly, the flap is frozen and “banked” for later replacement. There are reports of some mineral loss from the flap after replacement, and occasional infection. And occasionally the entire piece is misplaced. Another disadvantage is that if the patient moves away or presents to another hospital for flap replacement, the logistics of transferring a frozen piece of bone are very challenging.

4. Some centers just throw the bone flap away. This necessitates replacing it with some other material like metal or plastic. This tends to be more complicated and expensive, since the replacement needs to be sculpted to fit the existing gap.

So which flap management technique is best? Unfortunately, we don’t know yet, and probably never will. Your neurosurgeons will have their favorite technique, and that will ultimately be the option of choice.

Reference: Bone flap management in neurosurgery. Rev Neuroscience 17(2):133-137, 2009.

EAST 2017 #8: When Is “Mild TBI” Not So Mild?

Traumatic brain injury (TBI) is very common, with the majority falling into the “mild” category. This is usually defined as patients with injury to the head and a GCS of 13-15. These uncomplicated patients are frequently discharged from the emergency department, or undergo only a brief evaluation if admitted for other reasons.

The group at Shock Trauma focused on a less appreciated subset of mild TBI patients, those whose condition is a little more complicated. Specifically, these are patients with GCS 13-14 with positive findings on head CT leading to a calculated abbreviated injury score (head) of > 2, and some persistence of their symptoms while in the hospital. At many hospitals (including my own), these patients receive an inpatient TBI evaluation. But if they pass this initial screening, they are not consistently referred for any outpatient TBI followup.

Are these mild, complicated TBI patients (mcTBI) unique? Do they behave the same as the uncomplicated ones? The research group performed a prospective study on patients who sustained an mcTBI over a 4 month period.  They excluded patients with mental illness, dementia, and non-English speaking and homeless patients. They tried to contact patients up to three times after discharge to administer several standard tests and determine if they had any specific residual symptoms.

Here are the factoids:

  • Of the 142 patients with mcTBI during the study period, there was substantial attrition over time, with only 25 remaining at 6 months and 10 at one year
  • 64% of patients who responded at 6 months remained symptomatic. Depression, dizziness, and a feeling of impaired health were common.
  • 80% of patients still described symptoms at one year. The same complaints were most common, and some required changes in activities of daily living or assistive devices.

Bottom line: Although small and fraught with the usual problems in long-term tracking of urban trauma patients, this study is eye-opening. We too often dismiss “mild TBI” and being almost nothing, even in patients with positive findings on head CT. This work suggests that we are underestimating the needs of those patients. The authors used this data to design longer-term care processes for this subset of patients. Other centers should follow suit to make sure these patients’ post-injury needs are better met.

Questions and comments for the authors/presenters:

  • Describe the possible biases that patient selection and attrition may have had on the study
  • What type of TBI screening do you use in the hospital?
  • Given that a number of assessments were administered over the phone, I look forward to hearing some of the other details not listed in the abstract
  • Was there any correlation between specific CT findings and later symptoms?
  • Provide details of your long-term care programs for these patients
  • I enjoyed this thought provoking abstract!

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related posts:

Reference: Mild TBI is not ‘mild’… survivors tell their complicated stories. Quick Shot #3, EAST 2017.