I had the opportunity to spend the day with Dr. John Leddy, clinic director of the University of Buffalo Concussion Clinic  and renowned published author on concussions.  Dr. Leddy is first and foremost an inspiring clinician who has nothing but time, answers and options for his patients.  He also happens to be leading a paradigm shift when it comes to actively managing concussions!

Dr. Leddy observed early on in his Sports Medicine Career that athletes with concussions who did not recover in the usual time period (7 to 10 days) grew increasingly anxious, agitated and depressed as time marched on; which was compounded by continually being told “rest, rest and more rest”.  He started experimenting with light aerobic exercise for his athletes with prolonged concussion symptoms back in 2007 and noticed many athlete’s had a threshold at which exercise aggravated their concussion symptoms.  He also noticed when he kept the exercise of concussed athlete’s below that physiologic threshold, those athlete’s seemed to recover quicker.  In 2010 he published “A preliminary study of sub-symptom threshold exercise training for refractory post-concussion syndrome”.  Clinician’s, researchers and concussion experts everywhere scoffed at the notion of exercise to treat post-concussion symptoms.  Five years later the recent 2012 Zurich Guidelines state: “the current published evidence evaluating the effect of rest following a sports-related concussion is sparse…low-level exercise for those who are slow to recover may be of benefit”.

Below are some bits and pieces of my questions, conversations and observations with Dr. Leddy in his concussion clinic:

What interventions do you use to treat concussions?

The vast majority of concussion patients present with cervical (neck) and vestibular (balance) dysfunction.  Post concussion symptoms (PCS), such as headache, dizziness and nausea typically resolve on their own in less than 2 weeks, however in his experience the cervical and vestibular dysfunction remains long after PCS, so it is important to have both of those areas addressed early on.  He refers to many different trusted chiropractors and physical therapists in the Buffalo area.

Many patients present with cognitive and/or emotional disturbances…Dr. Leddy has a Neuropsychologist, Dr. Baker, that works in his clinic to address these concerns with patients.  Dr. Baker helps patients deal with issues such as sleep hygiene or work/school concerns or helps establish an emotional support network for the patient.

For patients with suspected physiological PCS (which he describes as a systemic dysfunction affecting the heart and autonomic nervous system…. basically patients that report exercise aggravates their symptoms.) he uses the treadmill test.  Dr. Leddy uses the treadmill test to determine if a physiological threshold exists, and if so, uses this information to design a sub-symptom aerobic exercise treatment program (see below).

Medications also play a role in certain circumstances…ie. muscle relaxants or sleep meds.

What is the treadmill test?

The treadmill test is a graded exercise assessment (modified slightly from the Balke protocol) to determine if there is a level of exertion that exacerbates concussion symptoms.  Heart rate and blood pressure (Dr. Leddy noted significant variability with blood pressure and said heart rate alone is sufficient) is monitored to determine aerobic exercise intensity for treatment.  The test generally takes between 10 and 20 minutes to complete.

The testing protocol looks like this…if you are 5’5” or taller you start at 3.6mph (5.8km/hr), if you are less than 5’5” you start at 3.2mph (5.2km/hr).  Each minute the treadmill incline is increased by 1 percent, to a maximum of 15 (their clinic treadmill maxes out at an incline of 15) and if the patient can go further the speed is increased by 0.3mph each minute for increased exertion.

Each minute interval the patient is asked to rate their overall condition (a likert scale visible in front of the treadmill for easy access), on a scale from 0 to 10.  0-feel terrific, 1-2 feel some symptoms but quite tolerable, 3-4 symptoms a little worse, 5-6 symptoms worse, 7-8 symptoms much worse and 9-10 feel terrible worst I ever felt.  Each minute the patient is also asked to rate their exertion level using the Borg rating of perceived exertion (RPE) scale .

To see the treadmill test in action check out the 4 videos here.

Baseline overall condition rating and RPE are established prior to starting the treadmill test.  A change of 2-3 points on the overall condition rating or the emergence of a post-concussion symptom is an indicator to stop the test.  For research purposes, standardization of when to stop the test is still being discussed and established.

The overall condition rating, RPE and heart rate measurements at each minute intervals are used to determine if a physiological threshold for post-concussive symptoms exist.  If so, a graded exercise protocol may be of clinical benefit.

Of Note Dr. Leddy also stated that in the absence of a treadmill, other controlled exercise procedures (ie. Bike or elliptical) with careful heart rate monitoring could also be adapted to both test (and determine physiologic threshold) and design a sub-threshold exercise protocol. 

What is the exercise protocol once the treadmill test has been performed?

Dr. Leddy recommends 80% of the physiological threshold, using heart rate as the guide, 20 minutes daily.  He follows up with his patients to determine if the sub-symptom threshold exercises are well tolerated, and then progresses intensity in the range of 5 to 10bpm generally after 1-2 weeks (depending on the patient, goals etc…).

Who would you recommend perform a treadmill test?

Generally speaking athletes or active individuals do well with this protocol.  These are people that generally present clinically because their symptoms are limiting them from returning to their pre-injury activity level.  There are also many motor vehicle accident or work related head trauma patients who report with increasing levels of physical and mental exertion that their PCS is exacerbated.  One symptom he finds that correlates well with generalized physiological dysfunction is a throbbing or generalized pressure in the head.    A high risk patient, such as a patient with advanced age, poor physical condition, difficulty with clinical balance tests or problematic medical co-morbidities may not be well suited for the treadmill test and subsequent sub-threshold aerobic exercise intervention.

(for clinicians) What examination procedures do you use to monitor your concussion patients?

Post concussion symptom scale (similar to that of the SCAT3), oculomotor “H” test (looking for nystagmus), convergence test (finger clearly tracked without change to 6cm or less as normal) and horizontal saccade testing using two fingers approximately a foot apart (inability to perform, exacerbates dizziness or other PCS)…this last test was new to me for concussion eval.

Balance testing includes rhomberg’s test, tandem gait and single leg stance.

Research projects in progress?

They have a paper coming out that will challenge the clinical utility of neuropsychology testing (ImPACT) in determining return to play versus using the treadmill test.  In many of the cases followed the decision points for when an athlete could return to play differed between ImPACT and the treadmill test.

As an aside: Dr. Leddy believes neuropsychological testing is largely unnecessary, when determining return to play or otherwise.  It has become big business with massive lobbying to create need/demand/and in some cases legislature.

Dr. Leddy also said they are currently seeking large grants for an RCT as much of their research is retrospective in nature…Dr. Leddy commented on the difficulty executing such a study.

From a postgrad researcher….

We are currently performing the treadmill test on acutely concussed patients, 3 days post injury…this will set the stage for future research on acute symptomatic patients.

We have also just received a grant to study retired NFL and NHL players…obviously I probed this area, but the postgrad researcher was unable to elaborate.

Questions or comments regarding any of the above or Dr. Leddy’s work please let me know…and if I can’t answer them I can help direct your questions to Dr. Leddy.