A combination of the Glasgow Coma Scale (GCS), along with clinical variables such as pupillary reaction and computed tomography (CT) brain findings are utilised by most clinicians, but self-assessed to be accurate only 37% of the time.1
At the other end of the process following mTBI, most patients ‘recover fully’ but up to 15% experience persistent disabling problems including reduced functional ability, heightened emotional distress, and delayed return to work or school.2 Existing clinical tools to assess the extent of mTBI include the Galveston Orientation and Amnesia Test (GOAT), the (Modified) Oxford PTA Scale (MOPTAS), the Westmead post-traumatic amnesia (PTA) Scale (WPTAS and the Revised-WPTAS (2004, Ponsford version)*.3-6
* As noted in our Biobit Trail.
Limitations associated with these scales refer to imperfect accuracy, because not all answers to memory questions can be verified.7 Furthermore, several test items are retrospective in nature, and pictures are used instead of words as memory items, which may be impractical, especially in ED settings and the level of task difficulty with some questions routinely failed by control subjects.8
Westmead Post Traumatic Amnesia Scale (WPTAS)9
Of patients hospitalised for traumatic brain injury (TBI), most pass through a state of altered consciousness known as “post-traumatic amnesia” (PTA). Despite the lack of a consistent definition, PTA is widely used as a construct in neurosurgical practice to guide decision-making and prognosis. Accurate PTA assessment is important, because over-evaluation leads to excess social, financial and opportunity costs, whilst under-evaluation risks patient welfare. Whilst anterograde memory is certainly disrupted in PTA, PTA in fact involves a far more extensive memory disturbance. More instructively, the complete “post-TBI syndrome” also comprises an extensive cognitive deficit which includes a confusional state, as well as a behavioural disturbance characterised by acute agitation. Recently, impairments in attention and executive functioning have also been emphasised; indeed, some consider these the primary disturbance with PTA. Although all of these features were fully described (or implied) by the earliest pioneers, most current PTA scores do not assess the complete “post-TBI syndrome”. Currently, the Westmead PTA scale (WPTAS) directs most in-hospital TBI management throughout Australasia: however, in addition to general defects, specific limitations have been identified in the levels of evidence for WPTAS validity.
Canadian CT Head Rule (CCHR)10
The CCHR indicates that any one of the following findings is a high risk factor for neurologic interventions:
Glasgow glaucoma score (GCS) below 15 at 2 hours post injury Suspicion of an open or depressed skull fracture Any sign of a basal skull fracture (eg, hemotympanum, raccoon eyes, Battle sign, cerebrospinal fluid [CSF] otorrhea/rhinorrhea) Two or more episodes of vomiting Age 65 years or older
Medium risk factors for brain injury detection on CT scanning, per the CCHR, include the following:
Persistent retrograde amnesia of 30 minutes or longer A dangerous mechanism of injury (eg, pedestrian struck by a vehicle, being ejected from a vehicle, fall from 3 feet or higher or five stairs)
NOTE: The CCHR does not apply in nontrauma cases and in those who: have a GCS below 13, are younger than 16 years, are taking warfarin or have a bleeding disorder, or have an obvious open skull fracture.
New Orleans Criteria (NOC)11
The NOC indicate that the presence of any one of the following findings requires CT scanning of the head:
Headache Vomiting Age older than 60 years Drug/alcohol intoxication Persistent deficits in short-term memory Visible trauma above the clavicle Seizure
Patients should be advised to be aware of symptoms of postconcussive syndrome, which can develop over the weeks following an event. Diagnostic criteria include at least three of the following eight symptoms: headache, dizziness, fatigue, irritability, insomnia, concentration problems, memory difficulty, and/or stress/emotional/alcohol intolerance. If the patients play contact sports such as ice hockey or are at risk for a second impact, they should be counseled not to return to play until cleared by their primary physician to avoid secondary impact syndrome.
Military Acute Concussion Evaluation (MACE)12
In 2006 MACE was add to the list of tools to screen casualties. While the MACE has been well integrated into the military medical evaluation, it still relies on subjective recall of the events, may be affected by fatigue as other neuropsychological tests and has shown low sensitivity when administered greater than 12 h. Thus there remains a gap for the ability to objectively measure brain injury with a method that is not impacted by other factors such as extra-cranial injury (i.e., polytrauma), stress, fatigue, or battlefield conditions.
Sports Concussion Assessment Tool (SCAT5)13
The Sport Concussion Assessment Tool 5 is a standardized sideline concussion screening tool for use by medical professionals. The SCAT-5 can be used to assess athletes ages 13 and older for a variety of mental and physical changes following a head injury. Athletes ages 12 and younger should be assessed using the Child SCAT-5. The SCAT-5 can be given as a baseline for use post-injury, or as a standalone test. The SCAT-5 views the following areas:
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7. Marshman LA, Jakabek D, Hennessy M, et al. Post-traumatic amnesia. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia 2013;20(11):1475-81.
8. Jacobs B, van Ekert J, Vernooy LP, et al. Development and external validation of a new PTA assessment scale. BMC Neurology 2012;12(1):1-9.
9. Marshman LAG, et al. Post Traumatic Amnesia. Journal Neuro Clinical Science. Volume 20, Issue 11, Nov 2013, P 1475–1481
10. Kavalci C, Aksel G, Salt O, et al. Comparison of the Canadian CT head rule and the New Orleans criteria in patients with minor head injury. World J Emerg Surg. 2014 Apr 17;9:31.
11. Bernhardt DT. Concussion. Medscape Drugs & Diseases from WebMD. Updated: July 25, 2016. Available at: http://emedicine.medscape.com/article/92095-overview. Accessed January 13, 2017
12. Schmid K, et al, The Diagnosis of Traumatic Brain Injury on the Battlefield. Neurology, 2012; 3:90.