Central Sensitization and Pain Syndromes

This assignment delves into the concept of central sensitization, a key mechanism underlying numerous chronic pain syndromes. It focuses on the Central Sensitization Inventory (CSI), a validated tool used to measure the presence and severity of central sensitization. The assignment analyzes research studies utilizing the CSI in patients with different pain conditions, such as temporomandibular disorders and fibromyalgia. It also examines the clinical significance of identifying central sensitization and its implications for treatment strategies.

Running head: MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
Name of the Student
Name of the University
Author note

1MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
Measuring instrument: Central Sensitizing Inventory (CSI)
Central sensitization is a physiological situation of the nervous system in which, the
chronic pain is developed and maintained. In this situation, the neurons of the central nervous
system becomes hyperactiveand both the noxious and non-noxious stimuli becomes
hypersensitive. During this, the nerves stimulus becomes persistent and this is the prime cause of
pain in individuals. This phenomenon persists even after healing of the injury and it persists for a
longer time. There is a group of syndromes that is known as central sensitivity syndrome such as
irritable bowel pain, fibromyalgia, acute fatigue and central sensitization is one of the common
etiologies for these disorders. To understand the level of pain in the patients suffering from such
chronic pain, several quantitative tool has been developed (Kregel et al., 2016). According to the
research of Smart et al. (2012), a cross sectional study was employed in patients with low back
pain and referred for physiotherapy. After that a clinical criteria checklist containing two parts
were filled by the 15 selected physicians. After filling those 38 sign and symptom-based
checklist, the patients were given results with no pain and central sensitization of pain criteria. A
minimum 464 subjects were selected after meeting little clinical and subjective inclusion or
exclusion requirements, within which 256 were selected for nociceptive pain, 102 were selected
for peripheral neuropathic pain and 106 were selected for central sensitization pain. Data
screening and univariate analyses were done, in order to exclude nondiscriminatory symptoms
and signs. Results were analyzed using a subsequent analysis using binary logistic regression,
CSP versus non-CSP graph (Smart et al., 2012). Therefore, to perform the tests for CSI, very less
instruments are needed and those instruments are easily available for the physiotherapists. To
perform the test for CSI, minimum time is required as the physiotherapist will examine the
patient’s symptoms and signs of pain and will fill a 38-question checklist. This test can be

2MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
performed by physiotherapists, general physicians and experienced registered nurses. According
to another research project by Scerbo et al. (2017), Using CSI tool for the determination of the
pain level in patients suffering from chronic pain is easier and compact qualitative results are
obtained from this measuring instrument.
Measuring instrument: Sensory Hypersensitivity Scale
Central sensitization is one of the prime reason for chronic pain in individuals
suffering from disorders such as fibromyalgia, acute osteoporosis and others. There are
several interventions has been developed for the measurement and identification of this
amplified pain, and those measuring instruments are known as pain measuring scales.
Sensory Hypersensitivity Scale (SHS) is one of such scales that are utilized to measure
pain. The scale measures the level of pain by comparing state of normal people and
people affected with pain. In this test, nine sensory modalities such as taste, touch, smell,
hearing, allergies, pain, light, heat and cold are measured and compared with others
(normal or patients affected with chronic pain). Further, a 25 questionnaire containing 25
questions were filled and analyzed by physiotherapist to determine the level of pain.
According to the experiments of Mayer et al. (2012), SHS is one of the best measuring
instrument for identification and measurement of pain. Dixon et al. (2017) developed
procedure for the development of the SHS tool and for that; they conducted five studies
for different aspects of the SHS scale. All the patients were named as normal in the study
and all of the participants were provided with a 25-question containi8ng questionnaire.
These questionnaires were prepared depending on the pain level and assessment needs
and the response of each participant was assessed by an independent assessor (Mayer et
al., 2012). The study 1 was to develop the questionnaire; study 2 examined the internal

3MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
reliability of the scale, study 3 and 4 to develop validity, and 5 to re-access every
information needed. The test was performed on patients having chronic pain syndromes
and they were to answer 25 close-ended questions about their pain. The result compared
the pain scores of those patients with that of the normal patients to determine the level of
pain. The test needed minimal time to perform the measurement and less number of
instruments is needed for that. As in the experiment by Ang et al. (2011), the test was
performed by a group of general physicians and the procedure does not require any prior
training, general physicians, registered nurses, practice assistant, physiotherapist can
perform the test.
Measuring instrument: Fibro Problem Scale (FPS)
Fibromyalgia syndrome is a complex disorder that possesses tenderness, acute pain and
its symptoms are associated with other numerous syndromes such as depression, anxiety and
fatigue, cognitive dysfunctioning and stiffness of muscles. There are several reasons 40
occurrence of fibromyalgia in individuals over 30 year of age such as neurological,
physiological, genetic, traumatic and hormonal. The measuring scale was developed for the
measuring of the level of pain in patients and it is known as Fibro Problem Scale (Neblett et al.,
2015). FPS has a particular importance in patients who are affected with rheumatoid pains and
according to the assessments, maximum of the patients are affected with rheumatoid arthritis and
chronic syndromes with inflammatory disorders. The FPS scale primarily determines the
measurements of 5 typical symptoms of the fibromyalgia, these are fatigue, fog and function,
insomnia, blues, rigidity and Ow which is also known as pain and tenderness. Boomershine
(2015) conducted a research to identify and measure the fibromyalgia related pain in patients and
the measurement process includes a questionnaire that need to be filled by the patients about

4MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
their level and status of pain in past few weeks. The scores obtained buy each of the patients
were analyzed and was put in different categories. This FPS scale is divided into ten categories
in which ‘Zero’ determines no problem or the patients does not possess any fibromyalgia related
problem in his/her body and ‘Ten’ determines totally disabling problem or the patient is suffering
from high risk for disability. Researchers provided a form containing 10 dimensions to each of
these fibromyalgia patients and the patients had to fill each of these categories depending on the
level of the pain they are feeling. The patients were to assess their own symptoms, and pain
level by choosing options in the form (Boomershine, 2015). The procedure of the test took
minimal time for the researchers and the difficulty level was low. The patients conduct this test,
as they will be filling up the forms about their status of pain.Therefore, no further training or
experience is required for the staff. Hence, the test can be monitored by any of the authorities
such as general physician, practice assistant, registered nurse and physiotherapists.
Measuring instrument for Cortisol level in saliva
The level of cortisol in saliva can be used as a screening test for a wide array of disorders
including hypercortisolism, Oesophageal Visceral Hypersensitivity (OVH) and functional
heartburn. The measuring technique used to determine the level of electrical activity generated
by the neurons of those areas and the technique is known as CEP or cortical evoked potentials.
This technique measures and generated the integrity of the sensory pathway. It represents a
sequence of negative and positive voltage changes and further provides the sensory information.
The level of cortical can be used to identify the oesophageal balloon distension and perfusing of
acid. There are several research has been conducted about the level of cortical used to identify
the level of hypersensitivity. The research conducted by Yang et al. (2006) conducted the test in
21 right-handed patients affected with functional heartburn. These patients have a long history of

5MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
heartburn and the heartburn was characterized in them with pain sensation behind their chest
bone. All the patients were asked for consent about the study as they were stopped providing
with medication, proton pump inhibitors, anti-secretory medications and H2 receptor antagonists
from 2 weeks prior to the research. The human research review committee reviewed this study
and an adapted multi-lumen catheter united with manometer, acid-perfusion and balloon-
distention was used to access the level of cortical. Stepwise distension protocol was used to
understand the first sensitization of the pain and further the process was repeated 192 times to
obtain the average value of the stimuli. Cortical evoked potentials were registered using scalp
electrodes and for that, the process was analyzed using the recommendations of 10-20
international systems. One electrode was positioned on the forehead and another was positioned
on the left ear of the subjects. At every stimulation, the epoch data that is the tolerance level was
recorded. All recordings were displayed according to the common neurophysiological
convention. The CEP data were assessed and analyzed by an autonomous operator who was
experienced in neurophysiological analysis (Yang et al., 2006). Statistical result was further
implemented the perception threshold and the level of pain was compared for every patient with
the standard. The test process took 24 hours to be completed and needed trained and experienced
physicians to continue the process (Generaal et al., 2014).Therefore, only general physicians and
physiotherapists having proper knowledge of the process can continue the measurement
procedure. The cost of the measuring instruments are high as measuring electrical impulses
needs modern and advanced technology. Therefore, the test requires much more time and capital
to be performed and the results obtain from those results can be helpful in measurement and
identification of electrical impulses that leads to functional heartburn in patients.

6MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
Measuring instrument: Condition Pain Modulation
Condition Pain Modulation (CPM) is used to determine the endogenous capacity of
analgesia in healthy as well as pain-affected patients. There are several methodology that are
used to understand the elicit CPMresponses and such measuring scale uses different
physiological stimulations such as tonic phase stimulation that determine the slower movement
of muscles. Further, there are several other stimulations present in this category that determines
the pain of cardiac disease and arterial occlusion.The scale, which is used to determine these two
are painful occlusion cuff inflation scale and Ischemic stimulation. According to Hilgenberg‐Sydney
et al. (2016), the researchers took quantitative sensory testing model to determine the sensitivity
level in patients and initially 613 volunteer femaleswere chosen for the analysis. Further
exclusion criteria such as usage of analgesics, having neurological disabilities were excluded and
then only 80 women were selected for the process and were divided into four segments. CPM
test was performed with each of the patient. The pressure pain threshold was determined by
algometer. Further, mechanical pain threshold, ischemic pain threshold and cold pressure pain
threshold was also determined and a table with data containing all the statistical analysis was
presented. Each test session for every subject was performed by the same assessor and the
sequence of the tests was determined by draw. However, the IPT and CPM tests were performed
last because of their implications in pain modulation. Three special regions were assessed in each
patient, for each test such as the body of the masseter muscle at pain side or at the most painful
side, named trigeminal (TG) zone; the cervical (CV) zone, at C1 and C2 level at the pain side or
at the most painful side; and the thenar eminence in the palm of the non-dominant hand that was
named extra trigeminal (ET) zone. Higher score in the pain threshold determined the pain level
in patients. From the research, it was understood that the instrumentation of this measuring

7MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
instrument are difficult to use and need experience or training for application. Further, the cost of
the instrumentation are high. Therefore, general physicians, physiotherapists and registered
nurses having experience of conducting such test are eligible to conduct such test (La Touche et
al., 2017).
Measuring instrument for sympathetic functionality
It is known that the determination of the functional characteristics is collected from the
responses of the organs and the researchers are aiming to estimate such systematic nerve activity.
These nerve activities are helpful in determination of activities that lead to cardiac diseases,
sympathetic skin responses and the processes that are used to determine the heart rate variability
analysis. The heart rate variability analysis helps to access the autonomic cardiac regulation and
this is done through the quantification of sinus rhythm variability. The lower band derived from
this determined physiological oscillation compared to the normal heart rate. The measures that
are used to determine this phenomenon are Average of NN intervals, standard deviation of all
NN intervals and many more. The research from Van Oosterwijck et al. (2017), determined that
central sensitization is one of the major reasons of feeling of pain and in whiplash patients, is the
reason of development and maintenance of pain. The researchers conducted a systematic review
to understand the level of pain in patients with such syndrome and compared it with normal
people. The inclusion criteria was, patients should not be disabled and should have developed
pain after any trauma. These inclusion criteria included 24 articles and 22 of them were included
to understand the methodology for the sensitizing process. The researchers performed several
tests such as tilt table testing to detect the light head due to the occurrence of acute pain,
sympathetic skin response and so on. The researchers used six stimulations to identify the
functionality. Deep tissue stimulation (Using algometry and mechanical stimuli), nerve and skin

8MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
tissue stimulation (using pressure algometry in skin and muscle tissue), Thermal stimuli (using
pain thresholds), Electrical stimuli (Electrical stimulation bypasses peripheral receptors),
Injections or local anesthetics (to examine the role of nociceptive input), Sympathetic
Vasoconstrictor (to understand the involvement of in chronic whiplash-associated disorders).
The results were statistically analyzed and further calculations were made based on that result
(Van Oosterwijck et al., 2017). The tilt table test according to Chalayeet al. (2014), this test helps
to understand the blood pressure and flow of blood through arteries and heart rate, which is
responsible for the light head symptoms. Sympathetic skin responses are also used in the
research to identify the level of acute pain due to different kind of stimuli. The result form the
research determined that central sensitization was the prime reason behind the pain stimuli of the
patient and mechanical pressure was the reason behind it. The tilt table test determined the low
blood flow during the situation and the sensory testing was positive as the nerve stimuli was
generating severe pain in patients. The test procedure for this sensory testing took less time in the
research and the difficulty of the process was very low. Further, the determination of the tests
requires training and experience as statistical analysis was dependent of the nerve stimulus.
Therefore general physicians, registered nurses and assistant practitioners were able to perform
the task. The cost of the procedure was average and therefore, any healthcare organization can
start utilizing this technique for future prospects (Pfau et al., 2014).

9MEASURING INSTRUMENT OF CENTRAL SENSITIZATION
References
Ang, D. C., Chakr, R., France, C. R., Mazzuca, S. A., Stump, T. E., Hilligoss, J., &Lengerich, A.
(2011). Association of nociceptive responsivity with clinical pain and the moderating
effect of depression. The Journal of Pain, 12(3), 384-389.
Chalaye, P., Lafrenaye, S., Goffaux, P., &Marchand, S. (2014). The role of cardiovascular
activity in fibromyalgia and conditioned pain modulation. PAIN®, 155(6), 1064-1069.
Dixon, E. A., Benham, G., Sturgeon, J. A., Mackey, S., Johnson, K. A., & Younger, J. (2016).
Development of the Sensory Hypersensitivity Scale (SHS): a self-report tool for
assessing sensitivity to sensory stimuli. Journal of behavioral medicine, 39(3), 537-550.
Generaal, E., Vogelzangs, N., Macfarlane, G. J., Geenen, R., Smit, J. H., Penninx, B. W., &
Dekker, J. (2014). Reduced hypothalamic-pituitary-adrenal axis activity in chronic multi-
site musculoskeletal pain: partly masked by depressive and anxiety disorders. BMC
Musculoskeletal disorders, 15(1), 227.
Hilgenberg‐Sydney, P. B., Kowacs, P. A., & Conti, P. C. R. (2016). Somatosensory evaluation in
dysfunctional syndrome patients. Journal of oral rehabilitation, 43(2), 89-95.
Kregel, J., Vuijk, P. J., Descheemaeker, F., Keizer, D., van der Noord, R., Nijs, J., ... & van
Wilgen, P. (2016). The Dutch Central Sensitization Inventory (CSI): factor analysis,
discriminative power, and test-retest reliability. The Clinical journal of pain, 32(7), 624-
630.

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La Touche, R., Paris‐Alemany, A., Hidalgo‐Pérez, A., López‐de‐Uralde‐Villanueva, I., Angulo‐
Diaz‐Parreño, S., & Muñoz‐García, D. (2017). Evidence for central sensitization in
patients with temporomandibular disorders: a systematic review and meta‐analysis of
observational studies. Pain Practice.
Mayer, T. G., Neblett, R., Cohen, H., Howard, K. J., Choi, Y. H., Williams, M. J., ...&Gatchel,
R. J. (2012). The development and psychometric validation of the central sensitization
inventory. Pain Practice, 12(4), 276-285.
Neblett, R., Hartzell, M. M., Cohen, H., Mayer, T. G., Williams, M., Choi, Y., &Gatchel, R. J.
(2015). Ability of the central sensitization inventory to identify central sensitivity
syndromes in an outpatient chronic pain sample. The Clinical journal of pain, 31(4), 323-
332.
Pfau, D. B., Krumova, E. K., Treede, R. D., Baron, R., Toelle, T., Birklein, F., ...&Magerl, W.
(2014). Quantitative sensory testing in the German Research Network on Neuropathic
Pain (DFNS): reference data for the trunk and application in patients with chronic
postherpetic neuralgia. PAIN®, 155(5), 1002-1015.
S Boomershine, C. (2015). Fibromyalgia: the prototypical central sensitivity syndrome. Current
rheumatology reviews, 11(2), 131-145.
Scerbo, T., Colasurdo, J., Dunn, S., Unger, J., Nijs, J., & Cook, C. (2017). Measurement
Properties of the Central Sensitization Inventory: A Systematic Review. Pain Practice.

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Smart, K. M., Blake, C., Staines, A., Thacker, M., &Doody, C. (2012). Mechanisms-based
classifications of musculoskeletal pain: part 1 of 3: symptoms and signs of central
sensitisation in patients with low back (±leg) pain. Manual therapy, 17(4), 336-344.
Van Oosterwijck, J., Nijs, J., Meeus, M., & Paul, L. (2012). Evidence for central sensitization in
chronic whiplash: A systematic literature review. European journal of pain (London,
England).
Yang, M., Li, Z. S., Xu, X. R., Fang, D. C., Zou, D. W., Xu, G. M., ... &Tu, Z. X. (2006).
Characterization of cortical potentials evoked by oesophageal balloon distention and acid
perfusion in patients with functional heartburn. Neurogastroenterology& Motility, 18(4),
292-299.