This is reproduced from the guidelines published by St. Joseph’s and Fowler Kennedy:
POST-CONCUSSION SYNDROME MANAGEMENT GUIDELINES
The most recent Consensus Statement on Concussion in Sport has defined a concussion as a“complex pathophysiological process affecting the brain, induced by traumatic biomechanicalforces”. Concussions can be caused by a blow to the head, face, neck or body. This trauma willresult in a set of clinical symptoms that may or may not include loss of consciousness. A concussion will typically result in short lived, spontaneously resolving neurologic impairments and largely reflect a functional rather than structural injury. (1)
Current guidelines recommend that any athlete who has suffered a concussion be removed from play and not allowed to return until evaluated by a physician, even if they report being symptom free. (2) Current treatment following concussion includes physical and cognitive rest until asymptomatic, at which time a stepwise return to sport can be initiated. (1) The majority of sport-related concussions recover within a 7-10 day period from onset (80-90%), (1) but a minority of these subjects may experience persistent symptoms, cognitive and physical deficits beyond this point. (3)
When symptoms persist beyond the natural recovery period, the term post-concussion syndrome (PCS) can be applied. (4) There is confusion currently surrounding the definition of post- concussion syndrome with the World Health Organization suggestion that persistent symptoms lasting greater than 1 mo while the DSM-IV classficiation requires greater than 3 mo. (5,6)
The primary forms of treatment for PCS have traditionally included, rest, education, neurocognitive rehabilitation and antidepressants. These forms of treatment have shown little effectiveness in the treatment of PCS. (7) More recently, studies have begun looking at varying treatment options including vestibular rehabilitation (8,9), visual training (8-11), cardiovascular training (7,8,12-17) and treatment of cervical spine dysfunction (8) with some promising results.
This document is intended to provide the user with instruction and direction in the rehabilitation of PCS. The physiotherapist must exercise their best professional judgment to determine how tointegrate this protocol into an appropriate treatment plan. As an individual’s symptoms andprogress is variable, this protocol must be individualized. It is essential to ensure that any treatment should be performed with the goal of avoiding symptom exacerbation.
POST-CONCUSSION SYNDROME AND TREATMENT GUIDELINES1) CERVICOGENIC Background Cervical spine injury is well documented following a trauma; however, it is often overlooked following a concussion. Anatomically, the cervical spine is closely linked to structures that can cause many of the same symptoms as concussion. Cervicogenic headache frequently co-exists with complaints of dizziness, tinnitus, nausea, imbalance, hearing complaints and ear/eye pain. Baron (18) identified the greater occipital nerve (GON) as the source of these symptoms in a group of 147 patients whose chief complaints were dizziness (93%), tinnitus (4%), headache (3%) and ear discomfort (0.7 %).
Literature has reported the referral patterns of the three occipital nerve roots (C1-3) and their convergence on the nucleus caudalis of the trigeminal tract. These nerve roots along with the joint complexes (z-joint, ligaments, nerves, discs and muscles) have been identified as possible sources of head pain. Muscle trigger points have also been implicated in head pain, dizziness and nausea. (19)
The receptors in the cervical spine have many connections to the vestibular and visual apparatus. Dysfunction of the cervical receptors due to a cervicogenic headache can alter afferent input, subsequently changing integration of timing and sensorimotor control. Changes in cervical joint position sense, eye movement control and postural stability have been measured in patients with neck pain (20, 21)
1) SubjectiveReports Common subjective reports of cervicogenic headache include (22):
o Moderate to severe, non-throbbing pain, usually starting in the necko Episodes of varying duration or fluctuating, continuous paino Headaches commonly unilateral and provoked by neck movements,
prolonged postures or pressure on tender pointso Can present as pain on the opposite side when severe, but does not appear
isolated to opposite sideo Ipsilateral, non-radicular arm pain can occur frequentlyo Frequently co-exists with complaints of dizziness, tinnitus, nausea,
imbalance, hearing complaints, ear/eye pain
2) Flexion- Rotation Test (FRT) (23,24)
- Cervical spine is fully flexed and then rotated. Positive flexion-rotation test isthought to be related to dysfunction of C1/2
- Positive test = 15 degree difference in rotation on one side compared to the other.45 degrees on range considered normal
- Can be reliably used with subjective complaints of a headache (24)
- 90% sensitivity, 88% specificity (23)
- 3) Cranio-Cervical Flexion Test (CCFT) (25)
- Assesses the ability to isolate the deep neck flexors, accurately target specificpressure and to measure endurance
- Patient lying in supine with pressure biofeedback (PBU) under cervical lordosis
- Inflate PBU to 20mmHg and instruct patient in head nod using deep neck flexors
- Palpate for superficial muscle recruitment (ie. SCM, scalene) and look forimproper form, difficulty targeting or fatigue
- Hold 10 sec, 10 times before progressing
- Continue with sequential testing from 22-30mmHg
- Scoring is out of 100
- 4) PAIVM
- Performed in prone
- Most painful segment and hypomobile segment on PAIVM has a kappa value of .45-.76 (moderate to good) (24)
- 5) Length Tension Testing (LTT)
- Uneven loading of the upper cervical spine can be associated with degenerativechanges in the spine or abnormal length tension of muscles that attach to theocciput and upper cervical spine
- Length-tension testing of the following muscles should be considered (26):
o Sub-occipital muscleso Upper fibres of trapso Anterior/posterior scaleneo Levator Scapo Splenius capituso Masseter/temporalis
6) Cervical joint position sense
The treatment program implemented will depend on patient-specific assessment findings and patient tolerance. Treatment options for patients with cervicogenic pain and dysfunction include:
1) Range of Motion – unidirectional and/or combined movements 2) Mobilizations – as per assessment findings3) Deep Neck Flexor (DNF) training
- Can be performed in multiple positions: 1) sitting (with/without head support) 2) supine3) 4-point kneeling
- Can progress to DNF recruitment with extremity movement, addition of resistance or change in position4) Deep Neck Extensor (DNE) training
Can also be performed in multiple position and in combination with DNF
5) MuscleExtensibilityExercises Stretching
Muscle energy techniques 6) Posturalcorrection
7) CervicalProprioception Ex. head repositioning exercises, vestibular exercises
2) AUTONOMICBackgroundFollowing a concussion, a metabolic cascade of brain neurochemical changes produces an initial hypermetabolic state as the brain attempts to restore homeostasis. This is quickly followed by metabolic depression as cerebral blood flow (CBF) declines and the demands of brain energy begin to exceed their supply (27).
Concussion is also associated with other metabolic and physiologic changes such as:
- Greater HR at rest (28)
- Greater HR with physical (29) and cognitive stresses (30)
- Greater sympathetic and lower parasympathetic nervous system activity (29)
- Altered Heart Rate Variability (HRV) which reflects the brain-heart physiologicalconnection between the sympathetic and parasympathetic N.S. balance (31)
- Decreased CBF and disturbed cerebral autoregulation (ability to maintain CBF atrelatively constant levels)(32)Initial treatment of concussion consists of a period of physical and cognitive rest because symptoms can be exacerbated with these tasks in the acute post-injury phase (2). Exercise in this acute period may increase brain metabolic demand (increased ATP) at a time when the brain energy is compromised (33). Exercise too soon afterwards can also affect the production of brain-derived neurotrophic factor (BDNF) which promotes neuronal recovery (34).Beyond the acute stages, PCS treatment has traditionally consisted of rest, education, neurocognitive rehabilitation and anti-depressants with limited effectiveness (35,36). In this post- acute phase, exercise may provide some benefit to the patient with PCS such as: Increased parasympathetic activity and improved autonomic regulation (37) Increased global, regional and cerebral blood flow (38) Increased BDNF production with improved cognitive performance (12) Improved mood, sleep and depression (39, 40, 41)
Reduction in systemic markers of inflammation (42)
– Measures the autonomic response to positional changes– Pt lying for 8 minutes while wearing a heart rate monitor– The average heart rate for the last two minutes of lying is recorded– Pt then stands up. Heart rate is recorded after 15 seconds of standing and the average heart rate between 60-90 seconds is also recorded– An elevated heart rate between 60-90 seconds post standing may be indicative of poor recovery hard training, illness or stress
2) BikeTesting– Patient’s baseline SCAT2 scores are taken at rest, and resting heart rate is recorded– Patient begins riding at 50% of their maximum heart rate and symptoms are re-recorded every 5 min– After 5 minutes, if there is an increase in any one symptom, the patient is to stop riding. If no change or decrease in all symptoms, the patient may continue up to a time of 20 minutes– The patient is also advised to stop at any point in time if they note an exacerbation of symptoms– Treatment should start at an intensity of 80% of the maximum heart rate achieved before symptom exacerbation (sub-symptom threshold) (17)
Leddy et al found that the use of a graded exercise program resulted in an increased in thepatient’s max HR and BP threshold as well as their maximum exercise time.(15) Baker et. al also reported a 71% return to full activity following a graded exercise program. (13)
Based on their research, Leddy et al. recommend that the exercise program be an individualized, progressive, sub-symptom threshold aerobic exercise program. (15) Exercise options may include:
Stationary bike Treadmill walking/running Elliptical
As mentioned above, aerobic exercise begins at an intensity of 80% of the maximum heart rate achieved before symptom exacerbation (sub-symptom threshold).
The patient’s baselines symptoms are collected using the SCAT2 and are re-checked every 5 minutes to ensure no exacerbation has occurred. Patients are instructed to STOP aerobic exercise
if any worsening of symptoms. Once the patient can reach a 20-30 minutes of cardio with no increase in their symptoms, then the intensity can increased by approximately 10%. This increase in intensity may require an associated reduction in duration. It is recommended to increase duration first, then intensity. The end goal will be to reach 80-90% intensity for 20-30 minutes with no exacerbation of symptoms
Any exercise program should be performed on a regular schedule (ie. daily) and for sufficient duration to allow the regulatory and auto-regulatory systems to adapt. Patient should STOP aerobic activity if any exacerbation of symptoms.
3) VESTIBULAR Background Balance deficits and postural instability are commonly reported post-concussion (44, 45, 46). A study by Lovell et al (47) found that 43% of patients will report balance problems. Furthermore, symptoms that may negatively affect ones balance, such as dizziness (55%) and visual blurring or double vision (49%) are also frequently reported. Balance issues have been reported to last for years post-concussion (46).
As a result, the assessment and treatment of the vestibular system as well as postural stability are an important component of the physiotherapy plan post-concussion. The 3rd Annual Consensus Statement on Concussion has found that “postural stability testing provides a useful tool for objectively assessing the motor domain of neurologic function”. Postural control can be made up of different components including static stability, dynamic stability, anticipatory reactions and reactions to external forces (48). For this reason it may be advisable to implement a battery of tests to include all components of stability.
Vestibular rehabilitation has been used as a method of treatment in patients with persistent dizziness and balance deficits that have not resolved with rest. (9) Alsalaheen et al. implemented an individualized program consisting of gaze stabilization exercises, standing balance, walking with balance challenges and in a few cases canalith repositioning. Significant improvements were reported in self-report and performance measures post vestibular rehabilitation. (9)
Assessment Evaluation of balance should consist of tests that include both static and dynamic components.
Test consists of 6 conditions with eyes closed in 3 different stances: narrow based, single leg and tandem stance performed on level ground and a compliant surface (ie. Airex)Positions are held for 20 seconds and the examiner records the number of errors Errors include: removing hands from iliac crest, opening eyes, taking a step, stumbling, abducting or flexing the hip > 30 degrees and lifting the forefoot/heel off the ground
The maximum number of errors per position is 10Clinical acceptable reliability (0.80) was attained when BESS was administered 3 times in a single day or 2 times on separate days (49)
Dynamic Gait Index 8-item test with a 4-point ordinal scale with 0 representing severe impairment and
3 representing normal function Research has shown that the subtests of 1) “gait with vertical head turn”, 2) “gait
with horizontal head turn” and 3) “gait and pivot turn” correlated significantlywith self-reported balance problems (46)
MiniBEST (48) 14-item test with 4 “subscales” being tested:
o Anticipatory postural adjustmentso Postural responseso Sensory orientation while on compliant or inclined surfaceo Dynamic stability in gait, with or without a cognitive task
Each item scored on a 3-point scale from 0 (severe) to 2 (normal) Patient performs all balance tasks in flat heeled shoes or bare feet
BPPV testinga. Dix-Hallpike Test
o Patient seated with head rotated 45 degrees towards test sideo Patient rapidly taken supine with head extended 30 degreeso Ensure patient keeps eyes open and observe for nystagmuso Patient may also reports symptoms of vertigo
b. Head Roll Testo Patient lying supine with head elevated approximately 20 degreeso Roll head quickly to lefto Observe eyes for nystagmuso Bring head back to neutral position and roll head quickly to right and
observeo Affected side is the one that provokes the most vertigo and nystagmus
VOR Assessmenta. VOR cancellation
o Grasp patient’s head with both hands and tilt head forward to 30 degreeso Instruct patient to focus on your noseo Slowly move the patient’s head side to side while you move in same
direction with your faceo Note patient’s ability to maintain fixation and any saccadic eye
movements or reports of symptoms
b. VOR slowo Same setup as per the VOR cancellation testo Slowly move the patient’s head side to side while you remain stationaryo Note patient’s ability to maintain fixation on your nose or any reports of
c. Head Thrust Testo Same setup as per above
o Slowly move the patient’s head side to side, then quickly rotate thepatient’s head in one direction and stop
o Movement should be a small amplitude with position held at the endo Note patient’s ability to maintain fixation, saccadic eye movements or
reports of symptomso Forgo this test if significant pain or restriction in cervical spine mobility.
Instruct patient regarding quick movement prior to initiating the test.
- 1) Canalith Repositioning – as findings on Dix-Hallpike or Head Roll Test dictate
- 2) Balanceexercises Can progress from:
o 2-1 foot
o Firm to soft surfaceo Level ground to incline or uneven surfaceo Add upper/lower extremity movements, first without resistance and then
witho Decreased to increased # of tasks (ie. add cognitive task to balance)o Incorporate visual training exercises (as discussed below)o Sport/activity specific balance
- 3) VOR Exercises
- Substitution exercises – move eyes to a target and then head
- VOR exercise – keep focused on target while shaking head back and forth
- Can work side to side, up and down
- Can work in increasing speed, change base of support (ie. sitting to standing tosingle leg stance) or incorporate functional activities (ie. walking while looking)
- 4) Corestabilityexercises
- 5) Gaitexercises
4) VISION/VISUAL PROCESSING Background Studies have shown that 50-90% of individuals with an acquired brain injury demonstrate visual dysfunction. These visual deficits may be the result of trauma to primary or secondary visual pathways as well as the primary and visual associated visual cortices. (10, 11)
Signs and symptoms of visual dysfunction may include blurred vision, light sensitivity, slowed or loss of place while reading, peripheral vision restrictions, poor spatial judgement/depth perception and vestibular symptoms in crowded environments. (10, 11)
Vision plays an important role in balance, gait, driving and other activities of daily living, andtherefore, disturbances can have a profound effect on one’s physical abilities. Visual field deficits may also present a safety hazard as poor spatial awareness and depth perception can increase the risk of tripping, bumping into objects and falling. (10, 11)
Visual deficits, although separate from cognitive deficits can exacerbate cognitive difficulties such as memory, attention and concentration. (10)
It is therefore important to screen for visual dysfunction early in the rehabilitation process. Early intervention may also be advantageous because the first year post traumatic brain injury has been identified as an important period during which natural recovery occurs. (10)
Assessment1) Cover Test
- Have the patient look at a close target (ie. your nose)
- Cover one eye with your hand and remove it to the side of their face. Repeat 2-3x
- Assessing eye movement as the eye is uncovered. Exotropia is the eye movinginwards, esotropia is the eye moving outwards and vertical is the eye moving up or down.
o No movement of either eye = no strabismuso If one eye moves = strabismus on that sideo If both eyes moves = incorrect or alternating strabismus
- Evaluates the ability of the patient to locate and fixate on a target within theirvisual field
- Present a target at midline (approx. 16-20 inches from face). Patient should beable to located the target and fixate for several seconds (ie. 10 seconds)
- Repeat to left/right of midline
- Steady fixation is the ability to maintain fixation for several seconds. Unsteadyfixation is the ability to fixate but the inability to maintain the fixation. Finally, no fixation is the inability to find the target
3) Smooth Pursuits (11) Have the patient look at a target with their head straight (approx. 20 inches from
- The patient follows the moving target using only their eyes
- Move the target to the left about 45 degrees from the center, then move upwardsand downwards. Repeat the same pattern on the right
- Inability to direct their gaze in one or more directions is a sign of impairment
- Also observe the effort required to complete the task4) Saccades(11)
- Use 2 small targets at 20 inches away from the patient’s face and about 12 inchesapart
- With their head facing forward and looking between the two targets, have thepatient look back and forth at the two targets using only their eyes
- Abnormal finding is the eyes missing or over/undershooting the targets. Must alsoobserve the effort required to complete the task5) Convergence(11)
- Use a small target starting about 16 inches from the patient’s nose
- Slowly move the target towards the patient’s nose
- The Near Point of Convergence (NPC) is recorded when the patient reportsdiploplia (double vision) or loss of ocular alignment. Normal is 2-3 inches fromnose
- The Near Point of Discomfort for Convergence (NPDC) is recorded at the pointwhere the patient reports discomfort from fixation
- Slowly move the target away from the patient’s nose. Recovery is the point wherethe patient reports single vision again. Normal is 3-4 inches from the nose
- Scoring is as follows:
o Absent = no convergenceo Impaired = inability to converge on target within 12 cmo Intact = convergence less than 12 cm
- Stand at side of patient and ensure no objects in front of patient to orient them tomidline
- Eyes (but not head) follow a wand as you move it across their visual field at aconstat speed
- Patient tells you to stop when the wand is directly in front of their nose
- Can assess from either side, up and down
- Using a face diagram, draw a line indicating where the patient reported theirmidlineAll visual exercises can be performed in isolation or can be progressed by increasing speed, increasing duration, changing base of support or incorporating vestibular integration. All exercises should be performed within symptom tolerance.
- 1) Fixations
- Keep head still and move eyes to different target, hold vision on each target for afew seconds
- Gradually increase duration of fixation, or number/location of target
- 2) Pursuits
- Use eyes to track objects moving within the patient’s visual field (ie. ball on astring, pen)
- Gradually progress duration of movement, location and speed of object
- 3) Saccades Eyes will jump back and forth between two targets without moving the head Repeat as fast as possible Gradually progress speed or location of targets
- 4) Near/Far
- Hold onto a paper with a photo/word and have a second page on a wall in thedistance
- Using only their eyes, patient will look down at the image until it is in focus, thenlook up until image on wall is in focus
- Repeat as fast as possible
- 5) Vergence Brock String
o 3 beads on a string and hold string up to noseo Patient looks at closest bead which should look like a single bead. The
other two will appear as two beads (like the string is making a “Y”)o Move to the middle bead which should now look like a single bead, and
the others should appear double (like an “X”)o Move up and down the string and gradually progress speed
Pencil Push-upso Patient holds pencil in front of their nose at a distance where they see only
a single pencilo Patient slowly brings the pencil closer to their nose until the pencil appears
doubleo Hold for a few seconds and slowly move away from their noseo May gradually increase duration, number of repetitions
6) Visual/Vestibular Integration
- May progress balance tasks by adding head movements, ball for maintainingfixation or for tracking
- Progress task from 2 to 1 leg stance, add Airex or BOSU, incorporate functionalmovements such as lunges/squats/walking/running
- Incorporate visual field stimulation with objects such as Bodyblade, ball toss(up/down, bouncing on floor, against wall) Binasal Occlusion – Patient with visual dysfunction may benefit from the use of binasal occlusion, which involves placing translucent tape (cloudy scotch tape) on the medialportion of a pair of glasses (either the patient’s current glasses or a pair of frames without lenses). The width of the tape will vary depending on patient’s deficits and may decrease
over time. Tape can be placed vertically or at an angle depending on which is more beneficial to the patient (see picture below).
The use of binasal occlusion in individuals with post-trauma vision syndrome has been found to increase the amplitude of visual evoked potentials. This shows that the ambient process becomes more organized and provides more appropriate spatial information (50). These changes can result in improved tolerance for visual activities and a decrease in symptoms.
It is important to educate the patient with post-concussion syndrome on the appropriate performance and structuring of return toactivity. The goal is to graduallyincrease activity tolerance without
crossing the symptom threshold. As a result, the planning and pacing of activities is of utmost importance both at home and within the clinic setting.
Intially patients often do too muchactivity and only stop when theirsymptoms limit them. Then they restand once their symptoms subside theyincrease their activity level into the symptom or “danger zone”. They often repeat this patternover and over as represented in the Current Activity Pattern graph on the right.
Patients are advised that activities should remain below symptom threshold, as increases in symptoms can delay and be detrimental torecovery. Patients and therapists should settime restrictions for activities (based on
sub-symptom threshold) and should use a timer to ensure that the patient works only within the prescribed time parameters. This will allow the therapist to monitor the patient’s response to activity and will alsoteach the patient to self-pace and self- monitor while at home.
It may be appropriate to start with shortreps of exercise with rest in between orvarying between different types of activities (ie. switching from a visual to a cardio based task). This will also help the patient pace activities and structure their activity in an appropriate manner. Patients may also benefit from using a journal to plan their day ahead of time to ensure they are following guidelines and to assist the patient who is having difficulty with memory. A journal can also be useful to reflect back on to determine any cause and effect of setbacks which may occur while in treatment.
The goal is to return to full activities without any restrictions. However, patients with Post Concussion Syndrome whose symptoms are more severe and take longer to resolve may need to continue to plan and pace their activities on a longer term basis.
1) McCrory P, Meeuwisse W, Johnston K, Dvorak J, Aubry M, Molloy M, Cantu R. Consensus Statement on Concussion in Sport: The 3rd International Conference on Concussion in Sport Held in Zurich, November 2008. Journal of Athletic Training. 2009; 44(4): 434-448.
2) McCrory P, Johnston K, Meeuwisse W, Aubry M, Cantu R, Dvorak J, Graf-Baumann T, Kelly J, Lovell M, Schamasch P. Summary and Agreement Statement of the 2nd International Conference on Concussion in Sport, Prague 2004. Clinical Journal of Sports Medicine. 2005; 15(2): 48-55.
3) Binder LM, Rohling ML, Larrabee GJ. A review of mild head trauma. Part I: Meta-analytic review of neuropsychological studies. Journal of Clinical and Experimental Neuropsychology. 1997; 19(3): 421-431.
4) MTBI Guidelines Development Team. Guidelines for Mild Traumatic Brain Injury and Persistent Symptoms. Ontario Neurotrauma Foundation. 2010. Available from:www.onf.org/documents/Guidelines%20for%20Mild%20Traumatic%20Brain%20injury%20and %20Persistent%20Symptoms.pdf. Accessed 2012 June 3.
5) World Health Organization (WHO). International statistical classification of disease and health related problems, 10th ed. 1992.
6) American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 4thed. 1994
7) Willer B, Leddy JJ. Management of Concussion and Post-Concussion Syndrome. Current Treatment Options in Neurology. 2006; 8: 415-426.
8) Weightman MM, Bolgla R, McCulloch KL, Peterson MD. Physical Therapy Recommendations for Service Members with Mild Traumatic Brain Injury. Journal of Head Trauma Rehabilitation. 2010; 25(3): 206-218
9 ) Alsalaheen BA, Mucha A, Morris LO, Whitney SL, Furman JM, Camiolo-Reddy CE, Collins MW, Lovell MR, Sparto PJ. Vestibular Rehabilitation for Dizziness and Balance Disorders After Concussion. Journal of Neurologic Physical Therapy. 2010; 4:87-93
10) Greenwald BD, Kapoor N, Singh AD. Visual impairments in first year after traumatic brain injury. Brain Injury. 2012; 1-22.
11) Kapoor N, Ciuffreda KJ. Vision Disturbances Following Traumatic Brain Injury. Current Treatment Options in Neurology. 2002; 4: 271-280.
12) Griesbach GS, Hovda DA, Gomez-Pinilla F. Exercise-induced improvement in cognitive performance after traumatic brain injury in rats is dependent on BDNF activation. Brain Research. 2009; 1288: 105-115.
13) Baker JG, Freitas MS, Leddy JJ, Kozlowski KF, Willer BS. Return to Full Functioning after Graded Exercise Assessment and Progressive Exercise Treatment of Postconcussion Syndrome. Rehabilitation Research and Practice. 2012; 1-7.
14) Gagnon I, Galli C, Friedman D, Grilli L, Iverson GL. Active rehabilitation for children who are slow to recover following sport-related concussion. Brain Injury. 2009; 23(12): 956-964.
15) Leddy JJ, Kozlowski K, Fung M, Pendergast DR, Willer B. Regulatory and autoregulatory physiological dysfunction as a primary characteristic of post concussion syndrome: implications for treatment. NeuroRehabilitation. 2007;22(3):199-205.
16) Leddy JJ, Sandhu H, Sodhi V, Baker JG, Willer B. Rehabilitation of Concussion and Post- concussion Syndrome. Sports Health. 2012; 4(2): 147-154.
17) Leddy JJ, Kozlowski K, Donnelly JP, Pendergast DR, Epstein LH, Willer B. A Preliminary Study of Subsymptom Threshold Exercise Training for Refractory Post-Concussion Syndrome. Clinical Journal of Sports Medicine. 2010; 20: 21-27.
18) Baron EP, Cherian N, Tepper SJ. Role of greater occipital nerve blocks and trigger point injections for patients with dizziness and headache. Neurologist. 2011; 17(6): 312-317.
19) Travell JG, Simons DG, Simons LS, Cummings BD. Travell & Simons’ Myofascial Pain andDysfunction : The Trigger Point Manual. Lippincott Williams & Wilkins; 1998.
20) Strimpakos N. The assessment of the cervical spine. Part 2: strength and endurance/fatigue. Journal of Bodywork and Movement Therapies. 2011; 15(4): 417-430.
21) Treleaven J. Sensorimotor disturbances in neck disorders affecting postural stability, head and eye movement control. Manual Therapy. 2008; 13(1): 2-11.
22) Sjaastad O, Fredriksen TA, Pfaffenrath V. Cervicogenic Headache: Diagnostic Criteria. Headache. 1998; 38(6): 442-445.
23) Hall TM, Robinson KW, Fujinawa O, Akasaka K, Pyne EA. Intertester reliability and diagnostic validity of the cervical flexion-rotation test. Journal of Manipulative and Physiological Therapeutics. 2008; 31(4): 293-300.
24) Hall TM, Briffa K, Hopper D, Robinson KW. The relationship between cervicogenic headache and impairment determined by the flexion-rotation test. Journal of Manipulative and Physiological Therapeutics. 2010; 33(9): 666-671.
25) Jull GA, O’Leary SP, Falla DL. Clinical assessment of the deep cervical flexor muscles: thecraniocervical flexion test. Journal of Manipulative and Physiological Therapeutics. 2008; 31(7): 525-533
26) MacHutchon M, Sanzo P. Length Tension Testing of the Upper Quadrant: A Workbook of Manual Therapy Techniques. Active Potential Rehabilitation Services; 2007.
27) Giza CC, Hovda DA. The neurometabolic cascade of concussion. Journal of Athletic Training. 2001; 36(3): 228-235.
28) King ML, Lichtman SW, Seliger G, Ehert FA, Steinberg JS. Heart-rate variability in chronic traumatic brain injury. Brain Injury. 1997; 11(6): 445-453.
29) Gall B, Parkhouse W, Goodman D. Heart rate variability of recently concussed athletes at rest and exercise. Medicine and Science in Sport and Exercise. 2004; 36(8): 1269-1274.
30) Hanna-Pladdy B, Berry ZM, Bennett T, Phillips HL, Gouvier WD. Stress as a diagnostic challenge for postconcussive symptoms: sequelae of mild traumatic brain injury or physiological stress response. Clinical Neuropsychologist. 2001; 15(3): 289-304.
31) Pomeranz B, Macaulay RJ, Caudill MA, Kutz I, Adam D, Gordon D, Kilborn KM, Barger AC, Shannon DC, Cohen RJ. Assessment of autonomic function in humans by heart rate spectral analysis. American Journal of Physiology – Heart and Circulatory Physiology. 1985; 248: H151- H153.
32) Jünger EC, Newell DW, Grant GA, Avellino AM, Ghatan S, Douville CM, Lam AM, Aaslid R, Winn HR. Cerebral autoregulation following minor head injury. Journal of Neurosurgery. 1997; 86(3): 425-432.
33) Vissing J, Galbo H, Haller R. Exercise fuel mobilization in mitochondrial myopathy: A metabolic dilemma. Annals of Neurology. 1996; 40(4): 655-662.
34) Barde YA. Trophic factors and neuronal survival. Neuron. 1989; 2:1525-1534
35) Fann JR, Uomoto JM, Katon WJ. Sertraline in the Treatment of Major Depression Following Mild Traumatic Brain Injury. The Journal of Neuropsychiatry and Clinical Neurosciences. 2000; 12(2): 226-232.
36) Ho MR, Bennett TL. Efficacy of neuropsychological rehabilitation for mild-moderate traumatic brain injury. Archives of Clinical Neuropsychology. 1997; 12(1): 1-11.
37) Carter JB, Bannister EW, Blaber AP. Effect of Endurance Exercise on Autonomic Control of Heart Rate. Sports Medicine. 2003; 33(1): 33-46.
38) Doering TJ, Resch KL, Steuernagel B, Jurgen B, Schneider B, Fischer GC. Passive and Active Exercises Increase Cerebral Blood Flow Velocity in Young, Healthy Individuals. American Journal of Physical Medicine & Rehabilitation. 1998; 77(6): 490-493.
39) Scully D, Kremer J, Meade MM, Graham R, Dudgeon K. Physical exercise and psychological well being: a critical review. British Journal of Sports Medicine. 1998; 32(2): 111- 120
40) Youngstedt SD, Freelove-Charton JD. Exercise and Sleep. In: Faulkner G. Exercise, Health and Mental Health: Emerging Relationships. New York, NY. Taylor & Francis Group; 2005
41) North TC, McCullagh P, Tran ZV. Effect of Exercise on Depression. Exercise & Sport Science Reviews. 1990; 18(1): 379-416
42) Ford ES. Does Exercise Reduce Inflammation? Physical Activity and C-Reactive Protein Among US Adults. Epidemiology. 2002; 13(5): 561-568
43) Heikki Rusko Test, Canadian Sport Center, Calgary AB, 1993
44) Guskiewick KM, Ross SE, Marshall SW. Postural Stability and Neuropsychological Deficits After Concussion in Collegiate Athletes. Journal of Athletic Training. 2001; 36(3): 263-273
45) Gottshall K, Drake A, Gray N, McDonald E, Hoffer ME. Objective Vestibular Tests as Outcome Measures in Head Injury Patients. The Laryngoscope. 2003; 113: 1746-1750
46) Kleffelgaard I, Roe C, Soberg H, Bergland A. Associations among self-reported balance problems, post-concussion symptoms and performance-based tests: a longitudinal follow-up study. Disability & Rehabilitation. 2012; 34(9): 788-794
47) Lovell M, Collins M, Bradley J. Return to play following sports-related concussion. Clinics in Sports Medicine. 2004; 23(3): 421-441
48) Frachignoni F, Horak F, Godi M, Nardone A, Giordano A. Using Psychometric Techniques to Improve The Balance Evaluation Systems Test: The Mini-BESTest. Journal of Rehabilitation Medicine. 2010; 42: 323-331
49) Broglio SP, Zhu W, Sopiarz K, Park Y. Generalizability Theory Analysis of Balance Error Scoring System Reliability in Healthy Young Adults. Journal of Athletic Training. 2009; 44(5): 497-502
50) Padula W, Argyris S. Post Trauma Vision Syndrome and Visual Midline Shift Syndrome. NeuroRehabilitation. 1996; 6: 165-171.