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\begin{document}

\title{An active approach in the treatment of post-concussion syndrome -
Evidence-based practice in a collective case study}



\author[1]{Thomas Christensen}%
\author[1]{Marianne Kyvsgaard}%
\author[2]{Peter Vindelev}%
\author[3]{Sofie Joergensen}%
\author[1]{bodil wiberg larsson}%
\affil[1]{University College Copenhagen - Carlsberg Campus}%
\affil[2]{Rigshospitalet}%
\affil[3]{Bispebjerg Hospital}%


\vspace{-1em}



  
  \date{May 08, 2024}


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\selectlanguage{english}
\begin{abstract}
Rational, Aims and Objectives: Prolonged symptoms after a mTBI, known as
Post-Concussion Syndrome (PCS), remains a challenging area of
rehabilitation. Evidence shows that an active approach can improve
prognosis, however PCS is a multifaceted condition with many
comorbidities and large variety in patient response. This study
investigated the use of submaximal aerobic exercise and body awareness
therapy, and the influence on symptoms in PCS cases, viewed through the
lens of evidence-based practice (EBP). Method: Four cases were separated
into two case studies. Cases in Study A received an aerobic exercise
protocol consisting of 8 individual sessions distributed twice a week
over 4 weeks, with additional cervical endurance training. Cases in
Study B received a body awareness therapy protocol consisting of 6
guided practices distributed twice a week over 3 weeks. Using method
triangulation, both quantitative and qualitative data were gathered
through the use of the Rivermead Post-Concussion Questionnaire (RPQ) and
semi-structured interviews, as well as the Craniocervical Flexion Test
(CCFT) in Study A, and the Short Form-36v2 (SF-36) questionnaire in
study B. Lastly, research evidence on PCS was included to contextualize
cases. Results: Both cases in Study A showed marked improvements in
their RPQ scores, but only one showed improvement in the CCFT. In Study
B, one case improved in RPQ score and in the mental component of
SF-36v2, while the other case did not experience any significant change.
All cases expressed positive associations with the interventions during
the interviews. Conclusion: These results illustrate how an active and
individualized approach can represent important qualities that can be
applied to further and larger studies. Based on the results and
discussion of this paper, relevant findings and suggestions are
summarized in a modified EBP model, which may be of help to
practitioners in dealing with PCS patients in the clinical practice.%
\end{abstract}%



\sloppy


\textbf{Keywords}

Mind Body Therapy, Mild Traumatic Brain Injury, Aerobic Exercise,
Autonomic Nervous System, Physical Therapy Modalities, Neck

\section*{1. Introduction~}

{\label{introduction}}

In Denmark approximately 25.000 cases of mTBI are diagnosed each
year\textsuperscript{1} with an additional estimated 25\%
undiagnosed,\textsuperscript{2} bringing the national incidence rate up
to 545 pr. 100.000. This is in line with the international rate where
incidents of mTBI, including diagnosed and undiagnosed, are estimated to
be about 600 per 100.000 worldwide, or around 45 million a
year.\textsuperscript{3} Of these, roughly 75-90\% experience gradual
remission of symptoms within 14 days, whereas 10-25\% continue having
symptoms, which may then devolve into Post-Concussion Syndrome
(PCS).\textsuperscript{4,5} While no consensus on the timeframe exists,
PCS can be defined as experiencing persistent symptoms of a mTBI for
longer than 3 months, as by the DSM-5 criteria, with additional
psychosocial sequelae.\textsuperscript{6,7} Patients often experience
difficulties in maintaining their social, professional and physical
levels of activity, and may be at risk of not participating in and
contributing to the financial state of society. A Danish survey found
that 19\% of all mTBI patients were on sick leave for more than a month
and that 2\% had still not returned a year after the initial
trauma.\textsuperscript{8} In the U.S., a report from the Agency for
Health Research and Quality found that TBI patients across all levels of
severity had a higher prevalence of long term depression at 30\%, which
is more than three times the national average at 8-10\%, as well as
higher rates of anxiety and PTSD.\textsuperscript{9}

An increasing amount of evidence shows that an active approach, contrary
to earlier beliefs about a ''wait and see approach'', can improve
outcomes and long term prognosis.\textsuperscript{10--12} The
international consensus statement on Concussion in Sports from 2016 in
Berlin recommends a period of 24-48 hours of physical and cognitive rest
after the initial trauma, followed by a progressively active
rehabilitation.\textsuperscript{13} It is well established that PCS
patients can experience barriers towards physical and cognitive
activity, with higher levels of cognitive exertion associated with
longer duration of symptoms in some,\textsuperscript{14} and that
adequate management between rest and activity is a central yet complex
part of the recovery process.\textsuperscript{15--17} These barriers
often manifest as exercise intolerance, cervicogenic headaches, rapid
eye exhaustion, dizziness, nausea, excessive fatigue, and a low
threshold for managing sensory input.\textsuperscript{18--22} Therefore,
it is important to clarify the parameters of an active approach to
treatment in a rehabilitation setting. In this context, an active
approach can be both an up or downregulation of physical and mental
stimulation, as well as providing education and tools to promote patient
self-efficacy.

One of the major challenges in dealing with PCS is categorizing the
underlying pathologies and understanding their effect on the
symptomatology, to which the evidence suggests a multitude of
neurophysiological and psychosomatic mechanisms. These mechanisms
include disruptions in cerebral blood flow
(CBF),\textsuperscript{23,24}changes in brain
metabolism,\textsuperscript{25} axon damage,\textsuperscript{26} changes
in autonomic and neuroendocrine function,\textsuperscript{27--30}
cervical injury and postural weakness,\textsuperscript{31} disturbances
in the vestibular and oculomotor system,\textsuperscript{32,33} and
neuropsychological dysfunctions.\textsuperscript{34,35} These myriad of
components and overlapping comorbidities adds to the complexity of PCS,
and highlights the difficulties of having a single treatment regimen. It
may also explain the varying responses to clinical
assessment.\textsuperscript{36}

A useful tool in organizing and providing the most relevant care is the
evidence-based practice (EBP) model originally coined by
Sackett\textsuperscript{37} and further developed through
Straus\textsuperscript{38} and Howick.\textsuperscript{39} While
different iterations exists, the model formulates three dimensions of
best practice: Best Research Evidence which is the highest graded and
most appropriate evidence in the scientific literature, Clinical
Expertise which is the clinical experience and knowledge, and Patient
Preferences which is the individual patient preferences, their values or
larger group characteristics. Using the EBP model practitioners can more
easily stratify the individual variables and formulate a cohesive plan
of action to target the multifaceted nature of PCS.

By applying two distinct interventions, this paper will examine how an
active and individualized approach can be used in the treatment of PCS.
The empirical data will be derived from two case studies, each
consisting of two cases with separate protocols, highlighting the
aspects of overcoming symptoms of PCS with insight from the cases, as
well as an inclusion of the relevant literature. This will be viewed
through the lens of a modified EBP model and ultimately summarized in a
visual presentation, to more appropriately transfer knowledge to the
clinical practice.

\section*{2. Methodology}

{\label{methodology}}

In both case studies method triangulation was used as the foundation of
the study designs, including a quantifying positivistic approach to
measure changes in clinical symptoms as a result of the interventions,
combined with a qualitative humanistic approach used to gain an
understanding of the cases' subjective experiences of the interventions.
The quantitative data was gathered through clinical examination and
questionnaires, and the qualitative understanding was gathered through
the use of semi-structured interviews. Because of the volatile symptoms
of PCS, the interventions were designed as a cyclical process with the
intention of including cases by listening to their feedback and
adjusting protocols, if necessary, based on any potentially adverse
reactions. This design was inspired by Malterud's research spiral which
is based on a continuous evaluation and defining of the problem and
intervention, thus preparing researchers to be adaptable and increase
transferability to the rehabilitation.\textsuperscript{40,41}

\section*{2.1 Ethical Foundation}

{\label{ethical-foundation}}

Permission for initiating the study was granted from The Danish National
Committee on Health Research Ethics prior to the beginning of the
project, concluding that cases were not at risk of harm, and the ethical
aspects of the project were assessed according to the Helsinki
Declaration.\textsuperscript{42} Cases were given oral and written
information about the protocols and signed an informed consent form with
the right to withdraw at any time. All cases were anonymized, and
qualitative data collection was handled with discretion with no sharing
of personal information.

\subsection*{2.2 Case and Study
Descriptions~}

{\label{case-and-study-descriptions}}

Case characteristics are presented in Table 1 and 2. The four cases were
recruited through a collaboration with a center of rehabilitation in the
capital region of Denmark and separated into two different case studies,
Study A and Study B, examining two different intervention protocols.
Cases in Study A participated in a submaximal graded aerobic exercise
intervention supplemented by postural correction of the cervical spine
and cases in Study B participated in a modified body awareness
intervention with additional group feedback sessions.

TABLE 1

Study A Inclusion criteria; Persistent symptoms of mTBI for more than 12
months following initial trauma, above the age of 18 and able to sit on
a stationary bike without referred pain.

Study B inclusion criteria; Persistent symptoms of mTBI for more than 12
months following initial trauma, above the age of 18, able to stand for
a duration up to 20 minutes, able to lie flat on their backs.

Excluding criteria; Unable to communicate in Danish, unable to attend
twice a week and contraindicated disorders making the planned
interventions impossible.

TABLE 2

\subsection*{2.3 Data and Analysis}

{\label{data-and-analysis}}

All four cases underwent a clinical examination before the interventions
covering relevant injury history, current and previous work history,
social participation, daily activities and bodily functions in relation
to the International Classification of Functioning Disability and Health
(ICF) model.\textsuperscript{43} All cases were scored on the
Rivermead-Post Concussion Questionnaire (RPQ), a standardized
post-concussion questionnaire with two
subscores,\textsuperscript{44}pre- and post-intervention, as well as a
semi-structured qualitative interview post intervention. Additionally,
cases in Study A underwent a Craniocervical Flexion Test
(CCFT)\textsuperscript{45} pre and post intervention, and cases in Study
B were scored on the SF-36v2 Quality of Life (QOL)
questionnaire\textsuperscript{46} pre and post intervention. RPQ, SF-36
and CFFT have shown to be valid testing tools in measuring prolonged
symptoms of mTBI, QOL and cervical function in different population
groups with moderate to high construct validity and
reliability.\textsuperscript{47--50} Questionnaires followed the
guidelines for analysis of RPQ\textsuperscript{47} and
SF-36v2\textsuperscript{51,52} using simple comparative statistics in
calculating averages and the semi-structured interviews were recorded,
transcribed and analysed by identifying codes and sub-codes, which were
clustered ad modum Kvale.\textsuperscript{53} The CFFT was administered
as per standardized guidelines.\textsuperscript{45}

\subsection*{2.4 Interventions}

{\label{interventions}}

\textbf{Study A}

\textbf{Submaximal Graded Aerobic Exercise~}

The aerobic exercise was done on a stationary bike to reduce exposure of
cervical compression and impact forces, minimizing symptom exacerbation
due to something other than the exercise itself.~During the initial
session, cases were instructed to reach a baseline heart rate (HR) above
100 BPM if possible, while being monitored for any increase in symptoms
which would terminate the test. In each of the following sessions cases
then attempted to increase their HR by 10 BPM, on the condition that
symptoms were not aggravated. HR thresholds were noted during the first
and last session. The intervention consisted of 8 individual
consultations distributed twice a week over 4 weeks, with~the exercise
lasting 15 minutes each session.

\textbf{Correction of malalignment~}

Cases were given home exercises based on findings in the CCFT test and
posture analysis following Panjabi.\textsuperscript{54} These consisted
of low intensity endurance training of the deep cervical flexors with a
focus on muscle control and close attention not to activate any
superficial muscles, as well as additional static stretching. Exercises
were done daily in 1-3 sets of 10 repetitions and stretches were held
for 45 seconds up to 3 times a day.

\textbf{Study B}

\textbf{Body Awareness Therapy}

The series of movements were inspired by Basic Body Awareness Therapy
(BBAT) and designed in cooperation with a physical therapist specialized
in BBAT. Large cervical rotations and strenuous movements were removed
to minimize possible symptom exacerbation. Cases were guided in the key
principles, which emphasize that all movements should be performed with
a physical and cognitive presence, allowing them to stay grounded,
breathe freely and move energy-economically, in order to make the series
flow relaxed and naturally.\textsuperscript{55,56} All sessions were
concluded with patients doing a brief body scan lying supine on the
floor, followed by a short group feedback session. The intervention
consisted of 6 guided practices distributed twice a week over 3 weeks,
with each session lasting 45 minutes.

\section*{3. Results}

{\label{results}}

\subsection*{3.1 Study A}

{\label{study-a}}

\textbf{Rivermead Post-Concussion Questionnaire}

As shown in Fig. 1 and 2, Case 1 had a reduction from 12 to 8 (33\%) in
RPQ-3 score and 44 to 25 (43\%) in RPQ-13 score, pre- to
post-intervention. Case 2 had a similar reduction in both scores, going
from 5 to 3 (40\%) in RPQ-3 score and 22 to 13 (41\%) in RPQ-13 pre- to
post-intervention.

FIGURE 1

FIGURE 2

\textbf{CCFT and Aerobic Threshold}

Case 1 remained a positive grade 3 in the CCFT throughout the study.
Case 2 was initially scored as a positive grade 1 in the CCFT, managing
the requirements with shaky and uneven movements, but improved to a
positive grade 3 post intervention.

As shown in Fig. 3, Case 1 managed a working HR of 100 during the first
session and 126 in the last session. The exercise intensity, as a
percentage of a calculated maximum HR, went from 55\% in the first
session to 70\% in the last session. Case 2 managed a working HR of 119
during the first session and 138 in the last session. The exercise
intensity went from 73\% in the first session to 85\% in the last
session. Both cases experienced no aggravation of symptoms during the
exercise.

FIGURE 3

\textbf{Semi-Structured Interview}

As shown in Table 3, emerging from these codes were themes of protection
against overstimulation and the importance of being in a comfortable
setting. Cases explained how this was helpful in preventing them from
reaching their mental or physical symptom thresholds. Considering their
reduced tolerance to sensory input, controlling the surroundings lowered
unwanted stimuli and allowed cases to devote their energy to the
intervention itself, without dealing with unnecessary triggers. Both
cases described an initial feeling of a lifeless body and how they had
avoided exercise for a long time before the intervention. Strenuous
physical activity can lead to symptom exacerbation in many PCS patients
causing a negative feedback loop further reducing physical activity,
making their bodies less resilient long term. After the intervention
however, both cases expressed feelings of physical success and improved
physical confidence which enabled them to continue to exercise on their
own.

TABLE 3

\subsection*{3.2 Study B}

{\label{study-b}}

\textbf{Rivermead Post-Concussion Questionnaire}

As shown in Fig. 4 and 5, RPQ-3 score remained unchanged for Case 3 from
pre- to post-intervention, however there was an increase from 28 to 33
(15\%) in RPQ-13 score. Case 4 had a reduction in both scores, from 5 to
4 (20\%) in RPQ-3 score and 28 to 19 (32\%) in RPQ-13 score, pre- to
post intervention.

FIGURE 4

FIGURE 5

\textbf{Short Form-36}

As shown in Fig. 6, Case 3 had an increase in the physical component
from 30 to 32 (7\%) and the mental component from 37 to 40 (8\%) from
pre to post intervention.

Case 4 had a decline from 40 to 39 (3\%) in the physical component,
while the mental component increased, going from 32 to 50 (56\%) with a
notable improvement on questions regarding levels of concentration and
fatigue.

FIGURE 6

\textbf{Semi-Structured interview}

As shown in Table 4, emerging from these codes were the meaningfulness
of engaging in an acknowledging social space with others, and the
positive experience in meeting peers with the same condition and similar
challenges. Cases explained how they had withdrawn from social
activities due to symptoms and had experienced a loss in the ability to
nurture social relationships. Both cases highlighted that attending the
intervention had given them a sense of purpose and something to look
forward to during the week, which they emphasized was of great
importance. Here cases expressed their views on body awareness therapy
as a treatment tool, and the pros and cons of this type of activity
compared to other more familiar types, like aerobic exercise. Both cases
experienced some difficulty conceptualizing the idea initially, which
Case 3 continuously had issues with throughout the intervention. They
also expressed an improved ability to detect their bodily sensations and
Case 4 especially considered this a tool to help reduce unwanted tension
and improve self-efficacy. The final codes revolved around reflecting on
the intervention and improving ideas to apply to other protocols in the
future, as expressed by the cases. The cases underscored the importance
of the weekly group feedback session and conversations after each
session, which was done with a focus on progression and daily
strategies, and how this had helped create a constructive environment.
Lastly, the cases expressed that a longer intervention duration would be
needed for participants to feel fully comfortable in each other's
presence, and to improve one's own presence of body and mind during the
movements.

TABLE 4

\section*{4. Discussion}

{\label{discussion}}

PCS patients are characterized by their heterogeneity and the syndrome
is in many ways used as an umbrella-term for several complex and
overlapping physiological and psychological pathologies. When examining
the cases we found that, while having had similar experiences, they had
different primary symptoms, different concerns and varying degrees of
emotional and physical debilitation. Some researchers have argued that
dividing PCS into various subcategories, or so called `post-concussion
disorders', could be used to improve outcomes and better treat
underlying causes.\textsuperscript{28,57--59} Others have suggested the
use of the RPQ, with additional questionnaires, as a possible
classification system.\textsuperscript{60}~While categorizing the cause
and effect relationships remains important in advancing the treatment of
PCS, the exact mechanisms between symptomatology and pathology is still
unclear. Bearing this in mind, there is a need for a rehabilitation that
is multifaceted, explorative and tailored to the
individual.\textsuperscript{4}~To further reflect on this process, the
following section will examine the nature of PCS pathology and
rehabilitation through the lens of the EBD model, while contextualizing
our cases.

\subsection*{4.1 Best Research Evidence}

{\label{best-research-evidence}}

Dysfunction of the ANS, or dysautonomia, acutely following a mTBI has
been linked to symptoms of exercise intolerance, lowered tolerance to
mental and physical stimuli, decreased cognitive ability, increased
stress response and emotional
dysfunction.\textsuperscript{28,61,62}Prolonged dysautonomia is
prevalent in the PCS group, with a recent review finding at least one
form of autonomic dysregulation in the majority of
patients.\textsuperscript{27}~Evidence shows that the ANS plays a
central role in psychological well-being\textsuperscript{63--65}and that
declining mental health after a mTBI is unfortunately a common
occurrence,\textsuperscript{35,66} with PCS patients demonstrating
higher incidence rates of both depression and anxiety compared to
controls.\textsuperscript{67,68} Our cases reported an inability to deal
with large crowds and various degrees of anxiety, frustration, worry or
depression as well as reduced tolerance to external stimuli contributing
to social isolation. This is in line with what is often observed in the
clinical practice where many PCS patients will abstain from social
activities to prevent symptom exacerbation. This abstinence functions as
a negative feedback loop creating further withdrawal and worsening
symptoms.~Considering that prolonged social isolation is linked to poor
mental health outcomes in the general
population,\textsuperscript{69,70}it is not entirely clear to what
extent the relationship with PCS is causal or correlated. Furthermore,
depression and anxiety might be risk factors for initially developing
PCS.\textsuperscript{71,72} Yet, studies on rodents have found evidence
of causality, in which induced mTBI disrupts limbic system function,
subsequently leading to long lasting depressive, fearful and anxious
behavior.\textsuperscript{73--75} Whatever the case, the
neuropsychological nature of PCS makes providing psychosocial coping
strategies a viable part of the multidisciplinary approach, and some
reviews have supported the use of cognitive behavioral therapy in
improving psychosocial outcomes\textsuperscript{76}; however, more
research is needed.

Meditation and mindfulness,\textsuperscript{77--80} body awareness
therapy,\textsuperscript{81--83} breathing exercises and
stretching,\textsuperscript{84,85} have shown to be effective ways of
modulating the ANS, lower sympathetic activity and improve biomarkers of
stress in various populations. Little evidence exists on treatments
specifically addressing dysautonomia as a result of mTBI, although one
pilot study did show improvements in QOL and self-efficacy on a group of
PCS patients after undergoing a mindfulness-based
intervention.\textsuperscript{86} Moreover, studies show that meditation
can improve cognition and regulate CBF,\textsuperscript{77,87} making it
an area of interest considering that CBF disruptions are linked to mTBI
and PCS symptomatology.\textsuperscript{24,88}~The efficacy of
meditation techniques and body awareness strategies can vary between
individuals\textsuperscript{89} and some techniques can be harder to
conceptualize than others, which was illustrated by Case 3 who expressed
difficulty in this regard. Our modified BBAT intervention in Study B was
directed at addressing the high arousal and stimuli intolerant state of
our cases, hopefully modulating the ANS and reducing PCS symptoms. While
both cases reported positive associations with the sessions, only Case 4
experienced symptom relief and significant improved QOL. Considering
that the intervention lasted 3 weeks, a longer duration of exposure may
have been required to more accurately assess the protocol, as a duration
of up to 8 weeks has been necessary before experiencing the full
benefits of similar methods.\textsuperscript{90}

Exercise intolerance is a common phenomenon in PCS patients and all of
our cases reported having experienced symptom exacerbation during
physical activity. Studies have found increased blood pressure (BP), HR
and arterial CO2 in PCS patients compared to healthy controls during
exercise, which may be linked to the changes in CBF and a reduced
ability of the ANS to regulate orthostatic
BP.\textsuperscript{22,91,92}This exercise intolerance occurs at
different ranges of HR and while finding the appropriate range for the
individual can be challenging, abstaining from exercise and physical
activity entirely is not recommended.\textsuperscript{92}~Both cases in
Study A showed a significant decrease in their PCS symptoms
post-intervention and were ultimately able to increase their HR
intensity, relative to their maximum HR, during exercise by 15\% and
12\%, for Case 1 and 2 respectively, without symptom exacerbation.
However, as the cases simultaneously underwent cervical treatment, it is
not possible to isolate the results of the exercise intervention
completely. Yet our findings are in line with other studies showing
improvements in physiological exercise biomarkers and PCS symptoms using
similar protocols.\textsuperscript{59,91,93} This may be partly due to
changes in CBF, as a pilot study, using fMRI, found that PCS patients
had a normalization of brain activity and CBF after the implementation
of a submaximal aerobic intervention.\textsuperscript{94} An important
aspect of the protocol is keeping intensity levels below symptom
threshold, before gradually increasing the intensity while assessing
individual response. Early initiation of aerobic exercise has been
associated with a faster recovery\textsuperscript{95}; however,
overexertion at different stages post-mTBI can be
detrimental\textsuperscript{15,96--98}and some evidence suggests that
the appropriate intensity is timing-based.\textsuperscript{99} It is
therefore recommended that practitioners monitor progress under
controlled conditions and with the proper testing tools. A high quality
and specifically developed method for testing this is the Buffalo
Concussion Treadmill Test,\textsuperscript{100} but other testing
methods with comparable protocols could be similarly applied.

Whiplash is commonly associated with PCS and exists both as part of the
symptomatology, as well as a comorbidity. It has similar injury
biomechanics to mTBI, such as the abrupt acceleration and deceleration
of the cervical spine and head, and shares a majority of
symptoms.\textsuperscript{101} One of the underlying mechanisms behind
this may be cranial nerve trauma, including the vagus nerve which
regulates the ANS,\textsuperscript{102,103} either as a direct result of
impact, or as a secondary effect based on changes in arthrokinematics
and joint degeneration.\textsuperscript{104,105} Cervical trauma has
been linked to oculomotor deficiencies\textsuperscript{32,106,107} and
whether as a result of whiplash or otherwise, issues with convergence,
accommodation and saccades occur regularly after mTBI and often lingers
in patients with PCS.\textsuperscript{19,108} Screening for this, and
possibly referring to neuro-ophthalmologic treatment, is
recommended.\textsuperscript{109}

All our cases reported cervical stiffness and pain, and evidence shows
that a high prevalence of various cervical and periarticular impairments
are common after a mTBI. These include postural imbalances, myofascial
triggers, muscle weakness, decreased joint mobility and weakness of
cervical flexors associated with cervicogenic
headaches.\textsuperscript{110,111} Considering this, and that up to
50\% of whiplash patients still report symptoms a year after
injury,\textsuperscript{112} cervical pathology is a critical
consideration in the PCS rehabilitation.\textsuperscript{113--115} Both
cases in Study A reported reductions in cervical associated symptoms
such as dizziness, nausea, and headaches, although only Case 2 improved
in CCFT grading. These findings are inconclusive, but other studies have
suggested that deep flexor strengthening can have a positive effect on
neck-related issues in some PCS patients\textsuperscript{114} and that
cervical and vestibular rehabilitation may reduce cervicogenic
symptoms.\textsuperscript{116,117} A variety of manual treatments may
also improve outcomes, however, efficacy seems highly individual and
more research is needed.\textsuperscript{113,118} Clinically, some PCS
patients are sensitive to cervical treatment and may respond with
symptom exacerbation to mobilizations, manipulations, strengthening
exercises and even stretching.

\subsection*{4.2 Clinical Expertise}

{\label{clinical-expertise}}

When initiating the PCS rehabilitation, identifying potential physical
and mental barriers to activity, and acknowledging these limitations, is
an important part of the planning. The process requires submaximal
testing and treatment, and a deliberate slow progression as symptom
thresholds are often low in the early stages. By taking inspiration from
other chronic pain protocols, a proper pacing strategy can be useful in
building tolerance to the treatment,\textsuperscript{119} and using
positive reinforcement and education on the nature of PCS can help
demystify the condition. This includes focusing on solutions and brain
plasticity instead of limitations when communicating with the patient,
after the initial explanation on pathology, and may help avoid the
unwanted nocebo effects that many chronic pain patients can be
susceptible to.\textsuperscript{120,121}~Setbacks and symptom volatility
are to be expected even with thoughtful consideration to programming,
which is why the practitioner benefits from listening to the patient and
adjusting volume and intensity accordingly, as well as including an
appropriate frequency of examination and re-testing. Working on
acceptance of current disability may help improve emotional outcomes and
patient self-efficacy,\textsuperscript{122} and celebrating short term
goals helps improve patient motivation and long term
compliance.\textsuperscript{123,124} Lastly, a key part of administering
the rehabilitation is knowing when a referral is indicated and if
treatment is outside the bounds of expertise of the practitioner.

\subsection*{4.3 Patient preferences}

{\label{patient-preferences}}

PCS is in many ways a ``hidden condition'' not easily visible and with
no current standardized biomarkers for
diagnosis,\textsuperscript{125}and the path towards rehabilitation is
often confusing, and uncertain, for patients and practitioners alike.
Most general practitioners are not well equipped to treat PCS patients,
which is highlighted by the lack of standardized care, and rest is often
the only offered treatment strategy. Our cases expressed dissatisfaction
with their healthcare providers and felt neglected, as well as not
having been taken seriously. One of the emerging themes derived from the
cases was the importance of meeting other patients in similar
circumstances who could relate to them and inhabit an acknowledging
space to freely share experiences and discuss daily obstacles. This
acknowledgement and social exchange was seen as a central part of coping
with the condition, and should be viewed by practitioners as a
legitimate consideration for rehabilitation in the clinical practice.
The use of deliberate framing and the facilitation of a constructive and
accommodating environment in our studies were beneficial in dealing with
the psychosocial challenges. Cases further highlighted that being in a
safe environment, and adjusting for unwanted mental and physical
overstimulation, resulted in less exacerbation of symptoms. Besides the
benefits of rehabilitation on their mood, stamina and cognitive
function, our cases expressed a sense of meaning in their daily lives
when having something to attend, especially considering that three of
the cases were on sick leave, with none regularly engaging in scheduled
social events. The interventions themselves were seen as motivating
factors, regardless of any improvement in symptoms, suggesting that an
active approach has an inherent advantage compared to a passive or
non-active approach even before considering outcomes.~Through the
gathering of the qualitative data, including the group feedback
sessions, our cases helped clarify valuable areas of concern
illuminating patient preferences and individual perspectives on the
intervention protocols which would not have been possible otherwise.

\subsection*{4.4 Model of Conclusion}

{\label{model-of-conclusion}}

By taking advantage of the three dimensions of the EBP model as a
methodological approach to the PCS cases, this paper incorporated the:
Best Research Evidence, Clinical Expertise and Patient Preferences,
through an examination of the benefits of two distinct intervention
protocols. These results illustrate how an active and individualized
approach can represent important qualities that can be applied into
further and larger studies, and we recommend additional studies
regarding exposure to active, individualized and graded treatments to
patients dealing with PCS. Based on the results and discussion in this
paper, we have summarized relevant findings and suggestions in the
following modified EBP model (Fig. 7), which may be of help to
practitioners in the clinical practice.

FIGURE 7

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\textbf{Acknowledgement}

We would like to thank the Center for Rehabilitation of Brain Injury in
Copenhagen for hosting the facilities. We would also like to thank the
cases themselves, as their participation is highly valued and forms the
basis for this article. Finally, we wish to thank The University College
of Copenhagen for their support.

\textbf{Funding}

No funding was given for this study.

\textbf{Conflicts of Interest Statement~}

The authors declare no conflicts of interest.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image1/image1}

\end{center}
\end{figure}

Figure 1 - Results from the Rivermead Post Concussion Questionnaire
RPQ-3 score for Study A -- Case 1 and 2 - conducted at first
intervention and after the intervention. RPQ-3 score includes symptoms
of headache, dizziness and nausea. Each symptom is scored from 0 to 4 --
0=not experienced at all, 1=no longer a problem, 2=a mild problem, 3=a
moderate problem, 4=a severe problem. RPQ-3 range: 0-12\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image2/image2}

\end{center}
\end{figure}

Figure 2 - Results from the Rivermead Post Concussion Questionnaire
RPQ-13 score for case Study A -- Case 1 and 2 -- conducted at first
intervention and after the intervention. RPQ-13 score includes symptoms
of noise sensitivity, sleep disturbance, fatigue, irritability,
depression, frustration, poor memory, difficulty concentrating, reduced
cognitive function, blurry vision, light sensitivity, double vision and
restlessness. Each symptom is scored from 0 to 4 -- 0=not experienced at
all, 1=no longer a problem, 2=a mild problem, 3=a moderate problem, 4=a
severe problem. RPQ-13 range: 0-52\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image3/image3}

\end{center}
\end{figure}

Figure 3 - Graphic illustration showing the absolute HR and the exercise
intensity, expressed in percentages, first session and last session for
Case 1 and 2 in Study A\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image4/image4}

\end{center}
\end{figure}

Figure 4 - Results from the Rivermead Post Concussion Questionnaire
RPQ-3 score for case Study B -- Case 3 and 4 - conducted at first
intervention and after the intervention. RPQ-3 score includes symptoms
of headache, dizziness and nausea. Each symptom is scored from 0 to 4 --
0=not experienced at all, 1=no longer a problem, 2=a mild problem, 3=a
moderate problem, 4=a severe problem. RPQ-3 range: 0-12\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image5/image5}

\end{center}
\end{figure}

Figure 5 - Results from the Rivermead Post Concussion Questionnaire
RPQ-13 score for Study B -- Case 3 and 4 - conducted at first
intervention and after the intervention. RPQ-13 score includes symptoms
of noise sensitivity, sleep disturbance, fatigue, irritability,
depression, frustration, poor memory, difficulty concentrating, reduced
cognitive function, blurry vision, light sensitivity, double vision and
restlessness. Each symptom is scored from 0 to 4 -- 0=not experienced at
all, 1=no longer a problem, 2=a mild problem, 3=a moderate problem, 4=a
severe problem. RPQ-13 range: 0-52\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image6/image6}

\end{center}
\end{figure}

Figure 6 - Results from the SF-36 questionnaire for Study B -- Case 3
and 4 -- conducted before the first intervention and after the last
intervention. The questionnaire is separated into mental and physical
health, with higher scores signifying better quality of life\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image7/image7}

\end{center}
\end{figure}

Figure 7 - The modified EBP model directed at treating PCS in the
clinical practice, with bullet point suggestions encompassing the three
dimensions of Best Research Evidence, Clinical Expertise and Patient
Preferences\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-1/Figure-1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-2/Figure-2}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-3/Figure-3}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-4/Figure-4}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-5/Figure-5}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-6/Figure-6}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-7/Figure-7}

\end{center}
\end{figure}

\textbf{Hosted file}

\verb`Table 1.docx`  available at \url{https://authorea.com/users/339469/articles/465669-an-active-approach-in-the-treatment-of-post-concussion-syndrome-evidence-based-practice-in-a-collective-case-study}

\textbf{Hosted file}

\verb`Table 2.docx`  available at \url{https://authorea.com/users/339469/articles/465669-an-active-approach-in-the-treatment-of-post-concussion-syndrome-evidence-based-practice-in-a-collective-case-study}

\textbf{Hosted file}

\verb`Table 3.docx`  available at \url{https://authorea.com/users/339469/articles/465669-an-active-approach-in-the-treatment-of-post-concussion-syndrome-evidence-based-practice-in-a-collective-case-study}

\textbf{Hosted file}

\verb`Table 4.docx`  available at \url{https://authorea.com/users/339469/articles/465669-an-active-approach-in-the-treatment-of-post-concussion-syndrome-evidence-based-practice-in-a-collective-case-study}

\selectlanguage{english}
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\end{document}

