This conference was great. It was what a motorsport conference covering safety, medical and rescue issues should be. No topic was off limits, no presenter was protected from being challenged (and most audience challenges stuck to the rules of engagement), invited speakers were from a broad range of backgrounds (gender, profession, motorsport category and geography) and most appealing of all, there was a general air of desire to promote and progress improved understanding and practice.

(I don't know who the attribution for this algorithm originally lies with, but it's good.)

Maybe the ICMS 2016 AGM had the advantage of relative comparison but it mirrored the changes that have occurred in the critical care conference arena over the past 5 years (think SMACC, Critical Care Reviews and ICS SOA albeit with a much smaller target population and a little less fanfare).

You can check out the ICMS 2016 AGM program here, though it may no longer be available once the 2017 program is released.

You may be thinking that you have heard of this conference somewhere before and that would be true. Podcast 14 was with Dan Marin, the conveynor of the 2015 (and 2016) ICMS AGM. So I was looking forward to attending in person this time and as you might be able to tell, I was pretty happy with how it went. Each day was packed with goodies so I am going to review it over two or more posts. Certain topics may get a post of their own later on.

Wednesday, December 7, 2016

The role of concussion biomarkers - Alain Ptito

This was a good talk, yet there was no mention of serological biomarkers, rather it focussed on radiology and is relevant to the formal clinic-based, specialist assessment that occurs following removal from competition. A brief review of concussion pathophysiology (organic v functional, cumulative injury) and clinical features was followed by a description of key radiological features.
  • No changes due to concussion alone on CT of the brain.
  • No white matter changes on conventional MRI. Need techniques such as FLAIR and Diffusor Tensor Weighted imaging (DTI) but still has a false negative rate. {DTI is a group of MRI techniques and there is no agreement on which component is most indicative of concussion. Existing studies are small and heterogenous and DTI features appear to vary with time from the injury.}
  • fMRI during active tests such as pattern recognition and navigation exercises results in altered patterns of activation (volume, location) that appear to correlate with severity, timing and recovery of injury.

Formal neuropsychiatric cognitive testing for concussion demonstrates impaired response accuracy and speed that correlates with severity of injury; though there is little difference between controls and mild injury. The accuracy of concussion diagnosis appears to improve with combined testing; eg fMRI + Cognitive testing. Combined testing seems to be able to differentiate between a mild and moderate spectrum of injury. Interestingly, as there is both behavioural and emotional aspects to the concussion feature spectrum, depression severity also correlates with fMRI activation patterns.

For more details on neuroimaging in mTBI read these articles. They are chock full of technical language and physics so grab a mug of coco and settle in:

Dr Ptito briefly reviewed two techniques for brain injury rehabilitation called Repetitive Transcranial Magnetic Stimulation (rTMS) and Tongue Stimulation Therapy, as possibly therapeutic options for concussion. They sound a bit voodoo but look promising from the videos that were shown; however, no supporting reference literature was cited and it would have been good to see trial data rather than showcase videos. In fairness, my own search for supportive literature didn't reveal much outside of its use in neuropsychiatry where the role of rTMS is still being explored.

Here's a paper that describes rTMS and how it might be applied to mTBI rehabilitation:
Here is a trial proposal to examine the use of rTMS in TBI:

Here are three papers exploring tongue stimulation for neurorehabilitation:

If anyone can contribute their knowledge of experience here, please tap away in the comments section below.

Neurosensory Assessment and Neurobiofeedback in The Management Of Concussion - Michael Hoffer, MD
Another good talk. Again, this talk started off with a quick review of concussion clinical features and then moved on to some commonly held concerns around using clinical assessment and some of the trackside screeening tests; which are really just formalised assemblies of concussion-associated symptoms and signs.

Symptom description (self report) as assessment of concussion is subjective, limited by lack of a common language (technical and linguistic) for inquiry and interpretation and can suffer from both patient bias (eg desire to return to competition) and physician/medic bias (e.g. desire to keep position on the team).

Examinable features are often thought of as objective but there is concern over how these may be gamed, especially for screening exams that rely on a pre-season baseline; the allegation being that well competitors might deliberately underperform at their baseline test in order to have a more achievable threshold should injury occur later on.

Michael then expanded upon a testing concept that Steve Olvey had briefly described during the FIA conference a week earlier; that of occulovestibuar reflex testing (OVRT). It involves testing a series of reflexes that coordinate body posture, head and eye movements. Through his experience in concussion management in the military and sports, this led to his involvement in advising on the development of a set of VR goggles called the IPAS Goggles as a novel diagnostic modality. If these deliver on what they promise we could well see concussion diagnosis evolve in a big way.

I tracked Michael down and interviewed him about the goggles which you can listen to here - Podcast 16 - Michael Hoffer and Virtual Reality for concussion.

In summary:
  • OVRT is typically a batch of 6 or so tests
  • Traditionally conducted in a dim room with the patient seated on a mobile chair and following instructions to follow, avoid or find dots projected on a wall while an infrared camera tracks and records their eye movement. It is expensive, bulky, needs a technician and requires significant training to interpret.
  • The IPAS Goggles are run using a laptop and a set of virtual reality-type goggles. The testing can be completed within 5-10 minutes. The system is portable, cheaper, can be conducted as a point of care test (Michael's team will be using the IPAS system in the circuit medical centre at all of the 2017 IndyCar races) and give an on-the-spot binary result of red ("consistent with concussion") or green ("concussion unlikely") via an algorithm that does not require specialist training to interpret. Additionally, the system can run different tests for diagnosis and rehab to avoid a learning effect.

The IPAS system looks promising for both initial diagnosis and return to play decision making. It may also facilitate tailoring individual patient rehab programs (Neuromodulation therapies) to areas of deficit rather than relying on a shotgun approach.

A Q&A session followed these two presentations which highlighted the following points on concussion diagnosis and management:
  • Current diagnostic recommendation = For now stick with symptom and clinical assessment, until developing modalities have been sufficiently validated.
  • VR goggle OVRT may soon prove useful at the event medical centre.
  • Work is being done on near infrared spectroscopy correlation with fMRI as trackside test.
  • Biomarkers still being explored. Alain Ptito reckons we are only 2-3 years away from having a useful serological concussion biomarker. Here's some background posted on this site two years ago: Concussion biomarkers - The new brain 'troponins'?  New biomarkers are being looked at since this post.
  • Alain and Michael's current views are that all of these tests should act as triggers for referral onwards for formal clinic based assessment and intervention. This may be more of a problem for club level events than high end professional motorsport.
  • There may be a role for neck strength conditioning in preventing concussion, which may partly explain increased incidence of concussion in female and paediatric athletes.
  • Happily, strict rest beyond 24 hours after injury does not appear to be beneficial and likely to be reflected in next Berlin Concussion Management Guidelines. No literature reference was provided for any part of this statement, but here's what I dug up:
 -  Benefits of Strict Rest After Acute Concussion: A Randomized Controlled Trial. Thomas DG et al. Pediatrics. January 2015. The study cohort was 11-22 year old patients presenting to the ED with an acute diagnosis of concussion. (There's a good critical appraisal of this loose study on the SGEM: Bang Your Head – Paediatric Concussions)

 - Physical Activity Level and Symptom Duration Are Not Associated After Concussion. David R. Howell et al. Am J Sports Med. Vol 44, Issue 4, 2016.. This paper includes an overview of some of the "strict rest" literature, suggesting that enforced physical and cognitive rest beyond the first 24 hours post injury may increase symptom burden and lead to longer recovery times.

 - The Berlin Concussion Management Guidelines are currently being written for publication some time soon, having been
hashed out at the recent 5th International Consensus Conference on Concussion in Sport.


Clinical Assessment of Concussion and Brain Health In Sports - Jeffrey Kutcher, MD
This was the final part of the concussion trilogy and came across as pragmatic. Having acknowledged that diagnostic modalities are evolving, Dr Kutcher posed the valid question:

"but what to do practically in the meantime?"

He then outlined how athletes held from activity will often feel unwell, whether concussed or not. This is labelled as "Unplugged syndrome" and can occur with both concussion and being restricted from usual activity. So as stated above by Dr Hoffer, prolonged rest beyond 24hrs may not be helpful.

Here's the strategy that Dr Kutcher proposes:

Mechanism + Clinical effect -> Likelihood of concussion
  1. Definite or probable -> Treat as concussion
  2. Possible -> Situational intervention, including allowing return to play if concussion not thought likely with ongoing close supervision for a variable period.
  3. Unlikely -> Return to play with supervision for a variable period

Dr Kutcher also questioned the value of baseline testing?
  • Easy to do, but ...
  • Little more than a formalised collection of clinical testing
  • Needs to be linked to a subsequent treatment regime to be truely useful
  • Potential for manipulation by players, medics/doctors and coaches/managers.

Everyone likes a graded return to play algorithm. Here's Jeffrey's:

Return to play process: B.R.A.I.N.
  • Bike (Smooth, negligible impact activity assuming we're not going downhill mountain biking)
  • Run
  • Agility (More cognitive load than the first two steps)
  • In red - simulating athlete-specific activities and cognitive load (I don't know what In Red refers to. Maybe it just fits the mnemonic)
  • No restriction

Software Systems with Crash Prediction Capabilities for Drivers and Riders - Jarno Zaffelli, ME

Some incidents are avoidable (predictable); some are in the hands of the gods. Jarno is an engineer who is involved in race track design and crash analysis. In the course of his work he posed a question and then realising that he had the skills and resources to find an answer, set about doing just that. The result was a fascinating talk on how big data from crashes and circuit characteristics followed by application to virtual modelling can lead to circuit design features tailored to predictable risk for that circuit.

Jarno has performed this analysis off his own bat on several well known race tracks and is able to produce circuit diagrams that highlight risk-weighted crash trajectories which in turn can be used to identify predictable hazards, escape routes and potential risk mitigation modifications. This can be tailored for any vehicle type for which crash data exists, be it car, bike, truck or otherwise.

The risk prediction algorithms also facilitates cost/benefit analysis of resourcing high risk locations with appropriate features (run off length, run off surface, barrier material, barrier positioning/angle, official positioning and protection).

Jarno insisted that the aim is not to create a bland race track but to objectively identify and quantify predictable areas of risk and reduce residual risk. The resulting race track design goes both ways, allowing low risk sections to bulk up their chalenge factor. The circuit anaysis facilitates resource allocation in high risk areas and removal of excessive or pointless protection from where it is not needed or helpful to ultimately create a more exciting race track from a driver and spectator perspective.

I really enjoyed this talk. It demonstrated the power of big data and how it can be used to improve the sport without resorting to knee-jerk protectionism.

Formula E and Electric Hazards in Motorsports - Jonathan Webb, MD

Dr Webb works for a medical equipment and provision company that also provides the response team for Formula E. So I
was a little wary of the significant potential for conflict of interest issues here. Thankfully this did not obviously occur in what turned out to be a useful outline of some of the key issues in the growing categories of electric powered race vehicles (e-racing).

Main dangers:
  • Electrical hazard
  • Thermal runaway (Li ion battery fires)
  • Complex burn injuries
  • Dry ice cold injuries
  • Hydroflouric acid exposure
  • Toxic gasses

Insulated gloves and matting provide an electrical resistance of 240000ohms.
800V/240000Ohm = 3.3mA (Pain threshold = 5mA)

Both DC and AC is present in Formula E.

There is an arcing risk during cable connection / disconnection. The main people at risk are the mechanics in the garage/pits and the response vehicle engineer tasked with rendering the vehicle safe at the scene of a crash. Hence they also wear a European Class 0 helmet and facemask.

Thermal runaway (Li Battery fire)
An individual battery cell overheats in turn heating its neighbour leading to a chain reaction, called thermal runaway. Once established it is virtually impossible to extinguish and instead is cooled while the rescue response proceeds and then left to burn itself out. The rescue implications are therefore:
  • Knowing the location of the battery
  • Knowing the safe car cut zones for disincarceration
  • Having a well practiced hazard minimisation approach (heat, electricity, toxic exposures)

Water can be safely used to cool thermal runaway as at high temperatures the battery ceases to conduct charge. {Can any fire technicians or engineers confirm this for me? Is there a threshold temperature for this?}. Temperatures greater than 500C have been recorded while the battery is burning. Following cooling, temperatures over 100C have been recorded even 24hrs later! The central management option is burying the vehicle in a sand pit. Glass bead heat sink technology is also being developed.

Further resources:

Short Course on Lithium-Ion Batteries from NASA.

Thermal Runaway and Safety of Large Lithium-Ion Battery Systems from Battcon, an international battery conference (Yeah, I know. Who would have thought?).

Spinal Motion during Race Car Driver Extracation - Tara Amenson, PhD
Dr Amrenson's talk drew attention to evolution of practice in an area that has recently been facing challenges. Her literature review of civilian practice, similar to those of others, showed that there is:
  • Little evidence benefit for the routine use of a c-spine collar
  • Little evidence of use of spine board for transport. Even extrication using a rigid board with dedicated training does not eliminate spinal movement.

To try and estimate the amount of movement occuring, Dixon et al conducted their often quoted biomechanical analysis trial. There is trial in motorsport competitors that used Triaxial Goniometry skin patches placed along the spines of volunteers in an attempt to use motion capture to analyse movements. As it is an unpublished trial, details were scarce.

How much motion is too much? asked Amrenson. Maybe it's the direction that matters - lateral, flexion, extension, rotation as posed by White & Panjabi in their 1990 textbook Clinical Biomechanics of the Spine.

Tara herself is looking at this in a motorsport context and has completed an initial pilot trial that sought to track spinal motion during extrication of a single healthy volunteer using accelerometers placed on the skin at strategic locations along the person's spine. The next move will be study spinal movement during extrication of a variety of competitors from different types of vehicle. The problem however is the confounders and error margins when trying to assess spinal column movement by using probes that are adhering to the overlying skin.

It was good to see this topic being proactively researched for the motorsport context but it will be better when the material actually gets published.

Here's an up to date review on spine biomechanics since the publication of White and Panjabi's text:

Fundamental biomechanics of the spine--What we have learned in the past 25 years and future directions. Oxland TR. J Biomech. 2016 Apr 11;49(6):817-32.

Value of Explosive Olympic Weightlifting in Motorsports - Leo Totten, MS

This talk started off well and looked like it would have application particularly to the pit crew mechanics, portraying them as athletes who work in short bursts of activity during races. There was, however, too much detail about specifics of different lifting techniques without clear relevance to motorsport populations for many of them.

And that was just Day 1! I headed off to central Indianapolis for dinner with a few friends feeling pretty pleased that I had made the effort to fly from the heat of Sydney to mid-winter North America. We ended up in a place on Mass. Avenue called Louie's Wine Dive which was a weird mix of hipster cafe with waiters and chefs who looked like they were out of prison on a day release program and really good food. I wandered in to the kitchen after the meal and had a chat with the chefs who were a really nice bunch of guys. Worth checking out if you are looking for somewhere to eat in Indianapolis.

Days 2 and 3 reviews will follow in the next few weeks.

As usual, your thoughts, responses and opinions are welcome below.