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Relating Chronic Pelvic Pain and Endometriosis to Signs of Sensitization and Myofascial Pain and Dysfunction

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Chronic pelvic pain is a frustrating symptom for patients with endometriosis and is frequently refractory to hormonal and surgical management. While these therapies target ectopic endometrial lesions, they do not directly address pain due to central sensitization of the nervous system and myofascial dysfunction, which can continue to generate pain from myofascial trigger points even after traditional treatments are optimized. This article provides a background for understanding how endometriosis facilitates remodeling of neural networks, contributing to sensitization and generation of myofascial trigger points. A framework for evaluating such sensitization and myofascial trigger points in a clinical setting is presented. Treatments that specifically address myofascial pain secondary to spontaneously painful myofascial trigger points and their putative mechanisms of action are also reviewed, including physical therapy, dry needling, anesthetic injections, and botulinum toxin injections.
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Relating Chronic Pelvic Pain and Endometriosis to Signs of
Sensitization and Myofascial Pain and Dysfunction
Jacqueline V. Aredo, BS1, Katrina J. Heyrana, MD, PhD2, Barbara I. Karp, MD1, Jay P. Shah,
MD3, and Pamela Stratton, MD1
1National Institute of Neurological Disorders and Stroke, Clinical Center, Intramural Research
Program NIH, Bethesda, Maryland 2Department of Obstetrics and Gynecology, University of
Rochester Medical Center, Rochester, New York 3Rehabilitation Medicine Department, Clinical
Center, Intramural Research Program NIH, Bethesda, Maryland
Abstract
Chronic pelvic pain is a frustrating symptom for patients with endometriosis and is frequently
refractory to hormonal and surgical management. While these therapies target ectopic endometrial
lesions, they do not directly address pain due to central sensitization of the nervous system and
myofascial dysfunction, which can continue to generate pain from myofascial trigger points even
after traditional treatments are optimized. This article provides a background for understanding
how endometriosis facilitates remodeling of neural networks, contributing to sensitization and
generation of myofascial trigger points. A framework for evaluating such sensitization and
myofascial trigger points in a clinical setting is presented. Treatments that specifically address
myofascial pain secondary to spontaneously painful myofascial trigger points and their putative
mechanisms of action are also reviewed, including physical therapy, dry needling, anesthetic
injections, and botulinum toxin injections.
Keywords
endometriosis; chronic pelvic pain; sensitization; myofascial trigger points; botulinum toxin
Chronic pelvic pain (CPP), defined as pain below the umbilicus for at least 6 months in
duration, is one of the most common clinical manifestations of endometriosis. Between 71
and 87% of women with CPP have laparoscopically proven endometriosis lesions,1 but
lesion location correlates poorly with the locations that patients identify as their most intense
areas of pain.2,3 Treatments for endometriosis have focused on hormonal therapies and
surgery, both of which target ectopic endometrial lesions. This approach can control the
extent of disease but often fails to provide a durable solution for associated pelvic pain.
Central sensitization and myofascial pain secondary to active (i.e., spontaneously painful)
myofascial trigger points (MTrPs) likely constitute another source of initiation,
amplification, and perpetuation of pain. Either could easily propagate pain-related symptoms
Address for correspondence: Pamela Stratton, MD, National Institute of Neurological Disorders and Stroke, Intramural Research
Program NIH, Bldg. 31, Room B2B32, 9000 Rockville Pike, Bethesda, MD 20892 (strattop@mail.nih.gov).
HHS Public Access
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Semin Reprod Med
. 2017 January ; 35(1): 88–97. doi:10.1055/s-0036-1597123.
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in women even after surgical and medical/hormonal treatment for endometriosis has been
optimized.
Unfortunately, both central sensitization and myofascial dysfunction are frequently
overlooked in the evaluation, diagnosis, and treatment of CPP associated with endometriosis.
In addition, many gynecologists have not received training in the assessment of myofascial
dysfunction, instead evaluating pelvic pain according to standard gynecological practice. In
this review, we will examine CPP related to endometriosis from a pain-centered perspective,
and discuss how sensitization and MTrPs are crucial components in the chronic pain women
experience that warrant a more comprehensive evaluation and targeted treatment.
Neural Mechanisms in Endometriosis-Associated Chronic Pelvic Pain: The
Dynamic Role of Sensitization
Pain is an unpleasant, subjective experience arising from the central nervous system (CNS)
that normally alerts and protects the body from potentially noxious stimuli.4 Chronic pain,
however, is pathological in itself, and often persists well after an inciting stimulus or injury
has resolved. It is a result of functional and structural rearrangements of the CNS that both
sustain the perception of pain and facilitate its expansion to distant regions.5 Given that
endometriosis is a disease in which hormonally dependent, inflammatory, ectopic
endometrial lesions engage the reproductive, endocrine, vascular, musculoskeletal, and
neuronal systems, there are several factors that may contribute to CPP. This section will
provide a model for CNS engagement in pain with endometriosis, and explain how
myofascial dysfunction may develop from and reinforce this relationship6 (Fig. 1).
Few hypotheses address the question of how ectopic endometrial lesions activate the nervous
system. One likely mechanism involves the innervation of lesions through neural sprouting
of sensory and sympathetic fibers that innervate nearby blood vessels.7 Since endometrial
lesions must be vascularized to survive and grow,8 the branching of blood vessels during
lesion development permits the simultaneous invasion of nerves, as the same factors that act
on sprouting blood vessels act on nerve fibers.9 Nerve growth factor (NGF), in particular,
promotes neurite outgrowth from sensory neurons and nociceptors10; is found in high levels
in peritoneal, deep adenomyotic, and ovarian endometriosis lesions11; and is associated with
greater nerve fiber density in peritoneal endometriosis lesions compared with normal
peritoneum.12 Newly sprouted nerve fibers may facilitate direct communication between the
endometrial growths and the CNS, establishing a bridge for central integration of visceral
sensory input.
Direct innervation of ectopic lesions by sensory and sympathetic nerve fibers has been
confirmed in studies using a rat model13 and in women with endometriosis.14 Furthermore,
their presence correlates with the severity of pelvic pain and dysmenorrhea.15 Sensory fibers
that innervate endometrial lesions are calcitonin gene-related peptide (CGRP)-positive,13,14
indicating that they include C-fiber nociceptors.16 Nociceptors respond to noxious stimuli in
the periphery, and are especially sensitive to immune and inflammatory factors which are
prevalent in endometriosis.
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The peritoneal fluid of women with endometriosis contains elevated levels of tumor necrosis
factor-α, interleukin (IL)-1, IL-6, IL-8, IL-10, RANTES, monocyte chemotactic protein-1,
and prostaglandins E2 and F, all of which directly sensitize or activate nociceptors or trigger
the release of activating substances from nearby cells.17 NGF found near endometriosis
lesions also activates nociceptors and recruits mast cells, which release inflammatory
molecules with degranulation.10,18
Repeated or prolonged activation of nociceptors results in lowering of their activation
threshold, a state known as peripheral sensitization.19 Once activated, nociceptors
themselves can facilitate sensitization by secreting neuropeptides such as substance P and
CGRP that are produced (by the dorsal root ganglion) and released antidromically into
peripheral tissue following repeated stimulation.20,21 These substances induce vasodilation,
increase local vascular permeability, and recruit and activate immune cells, causing
neurogenic inflammation.22 Changes also occur along the peripheral terminals of
nociceptors that permit further sensitization, such as the addition of new receptors to the cell
membrane and the increased expression of existing receptors.19 In addition, although many
visceral nociceptors are initially functionally silent even with intense stimulation, they may
be activated after being sufficiently sensitized by inflammation.23 Thus, peripheral
sensitization ultimately increases the excitability of nociceptors.
Ongoing nociceptor activation generates an afferent bombardment of noxious information
into the dorsal horn of the spinal cord.19 This process, in turn, induces structural and
functional changes throughout the spinal cord and more rostral structures, which ultimately
lead to central sensitization and evoked exaggerated responses to peripheral stimuli (Fig. 1).5
Furthermore, these dynamic alterations within the central circuitry can amplify and
perpetuate the perception of pain long after the initiating pathology resolves.5 Central
sensitization is manifested clinically as allodynia (pain to a non-noxious stimulus),
hyperalgesia (increased pain to a noxious stimulus), and referred pain (perceived pain
outside of the area of noxious stimulation).
Two aspects of central sensitization that are especially relevant to women with CPP and
endometriosis are viscerosomatic convergence and the viscerosomatic reflex. Visceral
afferents constitute only 2 to 7% of all afferent fibers that pass through each dorsal root
ganglion and synapse onto the spinal cord.24,25 As a result, almost all spinal neurons that
receive visceral input also receive somatosensory input from the muscle and skin, through a
process known as viscerosomatic convergence.26 Convergence of inputs hinders precise
localization and discrimination of sensory information.27 It is also the basis for referred
pain, and explains why visceral pathologies are commonly felt as pain in somatic structures
(particularly muscles) innervated by the same spinal segment. Furthermore, since visceral
afferent fibers terminate over several spinal segments above and below the segment level of
input, referred pain may be present in areas remote from the affected visceral organ,26,28 an
effect demonstrated in a rat model and in humans.29,30 Overall, viscerosomatic convergence
explains how ongoing noxious visceral input can sensitize multiple areas of the spinal cord,
generating the broad areas of allodynia, hyperalgesia, and referred pain seen with somatic
dysfunction.31
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Another consequence of central integration of visceral input is the development of the
viscerosomatic reflex. Visceral nociceptors converge with somatic nociceptors onto
interneurons in the spinal cord that activate both alpha and gamma motor neurons
innervating skeletal muscle.32 Ongoing visceral input can produce increased muscle tone
and spasm, usually in the area of pain referral. In addition, “guarding reflexes,” which
involve heightened sacral reflexes that are triggered by visceral pain and inflammation,
could contribute to muscle tightening and result in pelvic floor dysfunction.33 These
mechanisms may create an environment prone to generating or activating MTrPs.
The Contribution of Active Myofascial Trigger Points to Chronic Pelvic Pain
Myofascial pain arises from dysfunction in the muscle and surrounding connective tissue.
Despite being a common clinical problem with a lifetime prevalence of up to 85% in the
general population,34 myofascial pain is an underdiagnosed and often overlooked
component of nonarticular musculoskeletal pain. A hallmark of its diagnosis is the presence
of MTrPs in the symptomatic region, which are small, palpable, hyperirritable nodules
located on taut bands of skeletal muscle and that are in a sustained state of contracture.35
They can be spontaneously painful (i.e., active) or painful only upon perturbation (i.e.,
latent), and they often refer pain in predictable patterns. MTrPs may also cause motor and
autonomic disturbances, and affect the function of visceral organs.35 MTrPs are commonly
found in many chronic pain conditions, and, when active, typically present as a regional pain
syndrome.
MTrPs can be found throughout the body, including the pelvic floor, where they may refer
pain to the urethra, vagina, rectum, coccyx, sacrum, lower back, lower abdomen, and
posterior thighs.36 MTrPs may also refer pain from these muscles back to the pelvic
region,30,35–37 making myofascial pelvic pain difficult to localize. Dyspareunia, dyschezia,
and dysuria are the most common symptoms among women with myofascial pelvic pain,
though these symptoms can also reflect coincident gynecological, gastrointestinal, and
urological conditions.36
In general, MTrPs are believed to occur secondary to muscle overload or overuse. They are
also associated with a variety of medical conditions including those of metabolic, visceral,
endocrine, infectious, and psychological origin.35,37 Within the pelvic floor, previous
gynecological surgeries, childbirth, injury, sexual abuse, dyspareunia, and improper
mechanics may all contribute to MTrP formation.37 MTrPs can also develop secondary to
visceral disease.35 Studies have shown that MTrPs are associated with endometriosis38 and
interstitial cystitis/painful bladder syndrome39 as well as other gynecologic, genitourinary,
and gastrointestinal conditions, such as vulvodynia, irritable bowel syndrome, coccygodynia,
and urethral syndrome.36,40 MTrPs compound the pain experienced with any of these
conditions. Abdominal and pelvic MTrPs were commonly found in women with CPP and
current biopsy-proven endometriosis, and, adjusting for any history of endometriosis,
women with MTrPs were most likely to present with signs of sensitization in one clinical
study.38
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A myofascial component to pelvic pain adds another dimension to a patient’s disease and
requires its own diagnosis and treatment. Once formed, MTrPs can become a self-sustaining
source of pain even after the visceral insult has resolved.41 Active MTrPs, in particular, serve
as a source of ongoing nociception; they can reduce pain thresholds, enhance visceral and
referred pain, and sensitize the nervous system.42 In regard to endometriosis, MTrPs that
develop secondary to disease could sustain the pain and dysfunction despite lesion removal
and hormonal management.
Clinical Evaluation for Endometriosis-Related Pelvic Pain and Sensitization
Given the multifaceted nature of CPP associated with endometriosis, clinical evaluation
benefits from a systematic, interdisciplinary approach that includes a targeted pelvic
examination and a broader neuro-musculoskeletal pain assessment. Table 1 presents a
summary of this clinical assessment and complements the standard approach for a
gynecological assessment by focusing on evaluating pain related to endometriosis rather
than the lesions themselves or other noted pathology.
When taking a medical history, practitioners focus on the details regarding the history of
endometriosis and CPP. Often, having the patient complete a pain calendar for a menstrual
cycle can help reveal patterns of pain associated with menstruation and hormonal
fluctuations. Past and current treatments (pharmaceutical, hormonal, surgical, etc.) for
endometriosis or pain and the outcomes for each treatment aid to inform treatment options.
The pelvic examination for active MTrPs explores the external and internal pelvic areas as
well as the abdomen using only a single digit or one hand. This approach isolates areas of
tenderness and allows for assessment of myofascial dysfunction and sensitization. Since
abdominal wall muscle pain can refer to the pelvis,35 all regions of the abdominopelvic
region are examined for allodynia and diffuse tenderness, which can be signs of
sensitization.41 The abdomen is assessed for the number and location of abdominal muscle
MTrPs, and the severity of pain elicited with palpation. Sacroiliac (SI) joint tenderness is
also assessed.
The pelvic exam begins with an external assessment of the pelvic floor muscles for improper
positioning, trauma, or scars, followed by having the patient contract and relax her pelvic
floor muscles to assess for myofascial pain or hypertonicity. Using a single digit, the
examiner then individually palpates the pelvic floor muscles, first externally and then
internally, starting anteriorly with the superficial perineal muscles and moving posteriorly to
the coccyx, noting MTrPs, taut bands, or generalized tenderness that reproduce the patient’s
pain. The sphincter ani, levator ani, coccygeus, and obturator internus most commonly
harbor MTrPs.43 MTrPs in these muscles are not usually nodules, but instead are taut bands
that are tender, span the distance of the fiber, and are noticeably in spasm.30 Performing the
exam slowly and pausing when pain is elicited often gives the best insights into the degree
and extent of MTrP activation and local spasticity.
Bladder and urethral tenderness as well as uterosacral, forniceal, and vaginal tenderness and
nodularity are also examined using a single digit. A bimanual exam can then be performed
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to assess central uterine tenderness. Recording the pattern of abdominopelvic tenderness as
well as the location and pattern of worst pain provides a framework for considering pelvic
pain triggers.
To supplement the pelvic examination, a brief neuro-musculoskeletal pain assessment can
identify signs of widespread pain, central sensitization, and myofascial dysfunction. Each
dermatome and myotome is evaluated with the patient reporting when pain is evoked (Table
1). Dermatomes are assessed for allodynia and hyperalgesia bilaterally over the skin,
approximately 2.5 cm lateral to each spinal process. Allodynia is assessed using the pinch-
and-roll technique or by brushing the skin with a thin microfilament, while hyperalgesia is
assessed by scratching the skin with the edge of a paper clip or Wartenberg pinwheel. The
myotome is assessed for the presence of MTrPs. By examining a series of muscles spanning
the length of the body, the examiner can evaluate the distribution of myofascial dysfunction
and extent of overall sensitization.
These complementary exams together provide a more complete assessment of patients with
CPP associated with endometriosis. The pelvic exam is valuable for identifying pelvic floor
tenderness and spasm, which may be potential triggers for persistent pain and may warrant
directed treatment. The neuro-musculoskeletal exam identifies alterations in pain perception
beyond the pelvic muscles, placing the pelvic exam findings in the broader perspective of
global neuromuscular and myofascial dysfunction.
Myofascial Release Techniques for Chronic Pelvic Pain
Treatment for pelvic pain associated with endometriosis warrants identification and therapy
directed to the pathological findings that generate and sustain pain symptoms. Since a
myofascial source may contribute to endometriosis-associated CPP even after hormonal and
surgical treatment has been undertaken, a growing number of practitioners are exploring
pain management methods that directly address myofascial pain.
One set of treatment is collectively known as myofascial release, which involves physical
therapy and other manual techniques including deep pressure massage, stretching
techniques, joint mobilization, and foam rollers, often in combination with teaching about
strategies used to manage pain, including breathing and relaxation exercises.37,44 This dual
approach addresses physiological and psychological components of chronic myofascial pain,
alleviates MTrP-related pain, and furnishes patients with coping strategies to redirect their
focus during a painful episode. Small studies tout the effectiveness of these techniques in the
treatment of myofascial pelvic pain, including one retrospective study which showed that
physical therapy benefits up to 63% of patients who attempt it.37,45 However, no
randomized, controlled trials have compared physical therapy with the standard of care for
endometriosis patients with MTrPs.
MTrP injection, with or without a topical anesthetic (wet or dry needling, respectively), is
another common form of myofascial treatment being studied. The theoretical basis of MTrP
injection is that entry into a hypercontracted muscle causes mechanical disruption that
interrupts the aberrant sensory signals that cause MTrP formation.44 Direct injection of a
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local anesthetic such as lidocaine is thought to further blunt the ability to transmit pain
signals through these hyperactive neural networks, providing additional pain relief that may
be more durable than needling of MTrPs alone. Prospective studies using dry needling have
not been performed in the pelvic region. However, dry needling in other body regions has
been shown to reduce pain and is non-inferior to wet needling, though pain relief from MTrP
anesthetic injections is longer lasting.44,46 For CPP patients with MTrPs in the abdominal
wall, direct injections with lidocaine provided superior clinical response rates to physical
therapy out to 12 weeks after treatment,47 and small studies of CPP patients who received
lidocaine injections in the pelvic musculature report pain relief as well.48,49
Botulinum Toxin Type A: Alleviating Hypertonicity to Lessen Myofascial
Pelvic Pain Associated with Endometriosis
Botulinum toxin (BTX) is the first-line therapy for focal dystonias, and is an increasingly
common treatment for other neuromuscular conditions arising from excessive muscle
activity.50,51 Randomized, controlled trials evaluating the effectiveness of BTX in relieving
myofascial pain in the neck, cervicothoracic region, shoulder, and upper back have generated
mixed results.52–54 There have been a limited number of studies to date, including two
double-blind, placebo controlled trials, evaluating BTX injection into pelvic floor muscles
for CPP. Further investigation is required to explore this approach, including optimization of
dosage and injection technique; however, the current evidence suggests that BTX may be
effective in treating endometriosis-associated CPP.
The clinical efficacy of BTX in treating spasticity, dystonia, hemifacial spasm, overactive
bladder, and migraine has been well established. BTX is a neurotoxin produced by
Clostridium botulinum
that irreversibly blocks acetylcholine release at the neuromuscular
junction.55 This action prevents the transmission of signals that stimulate muscle fibers.
When the dose is carefully titrated, excessive muscle contraction and spasm can be eased
without muscle paralysis. Clinically, a reduction of muscle spasm and associated pain
results.55 Skeletal muscle strength decreases within 2 to 5 days after injection, reaches its
nadir within 2 weeks, and recovers gradually after that. The effects of BTX on the
neuromuscular junction are irreversible, requiring new motor axon regeneration and
restoration of the neuromuscular junction. The period of clinical efficacy typically lasts 3 to
6 months for approved indications, so that reinjection is required to maintain benefit. The
safety of repeated BTX injection has been established through over 20 years of clinical use.
Two toxin serotypes (A and B) and several brands of toxin are currently commercially
available.
The duration of therapeutic effects, well-characterized muscle relaxant activity, and evidence
of direct analgesia make BTX an ideal candidate for treatment of myofascial CPP in the
setting of endometriosis. Several case studies and small trials have examined the utility of
BTX injections for treatment of various types of CPP (Table 2). The first documented
gynecologic use for BTX in 1997 included electromyography (EMG) to identify hyperactive
areas of the anterior vaginal wall in a woman with vaginismus. A series of two injections
over 7 weeks resolved bladder, urethral, and vaginal pain symptoms.65 A subsequent series
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of studies from Australian researchers examined type A BTX for the treatment of levator ani
spasm and showed a reduction in resting pelvic floor pressure by manometry as well as a
statistically significant improvement in dyspareunia and nonmenstrual pelvic pain.56,59,61,66
A randomized placebo-controlled trial from this same group examining type A BTX for 60
women showed that only improvement in nonmenstrual pelvic pain was unique to the
treatment group, implying that dry needling may contribute to pain relief at MTrPs.56 Other
groups have observed benefits of BTX injections for dysmenorrhea and quality of life in
patients with pelvic floor spasm.62–64 Unfortunately, not all studies have shown efficacy; in
a small randomized controlled trial examining 60 women with vestibulodynia, a low dose of
type A BTX into the vestibule did not significantly improve pain or quality-of-life measures
at 3 or 6 months after injection compared with placebo.57 It is likely that differences in dose,
dilution, muscle selection, and injection technique contributed to the differences seen in
these studies’ outcomes. Further research is needed on each of these aspects of BTX
treatment.
At our center, we conducted a randomized placebo-controlled pilot study in which seven
women with CPP, most of whom had laparoscopically confirmed endometriosis, received
either 100 U onabotulinum toxin A diluted into 4 mL of saline or placebo injected
transvaginally into the areas of pelvic floor spasm in the levator ani muscles under EMG
guidance (data not published). The injections were part of a comprehensive approach to
pelvic pain after surgical treatment of endometriosis in which patients could also choose to
use hormonal contraceptives, progestin-releasing intrauterine devices (IUDs), analgesics,
and have pain and palliative care therapy including massage, acupuncture, and mind–body
therapies.
Women in both active drug and placebo groups experienced improvement in pain. The
duration of pain improvement was longer in those who received BTX (3.5 weeks for BTX
vs. 1 week for placebo). Women receiving BTX were more likely to be able to quantify the
extent and duration of benefit from injection, whereas those who received placebo reported
benefit in vague terms. These findings suggest, as in the Abbott et al study, that dry needling
of MTrPs may have provided at least some brief pain relief to women in the placebo
group.56 These preliminary data are difficult to interpret, as those receiving BTX had lower
overall pain severity prior to injection than those in the placebo group (3.6 vs. 8.5 on VAS
scale from 0 to 10). However, these data were promising enough that we are now conducting
a double-blind, placebo-controlled study of BTX for CPP in women with surgically
documented endometriosis (NCT01553201).
BTX is, thus, a promising treatment for endometriosis-associated CPP. With regard to the
myofascial contribution to CPP characterized by MTrPs of muscle fibers that are in a
prolonged state of contracture, BTX may be effective in relaxing the muscles of the pelvic
floor that are unlikely to respond to surgery or hormonal therapy, and that may not respond
to myofascial release techniques.
BTX may also have direct analgesic effects that complement the effects on muscle
relaxation.68 Although BTX is highly specific for cholinergic neurons, it has shown
additional effects on the secretion of peripheral and central neurotransmitters in culture and
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in mouse models.68 These studies have shown a decrease in the release of proinflammatory
neuropeptides such as substance P and CGRP, a resultant decrease in inflammation, and
alterations in intracellular trafficking patterns that, altogether, may contribute to an overall
decrease in pain and inflammation.68
In addition, the effects of BTX on pain may not be limited to peripheral benefits. The
inflammatory nature of the endometriosis lesions as well as the abnormal contracture of
MTrPs all contribute to a feed-forward mechanism that eventually restructures how pain is
centrally processed and experienced. Research studies have shown that the release of the
MTrPs is followed by a corresponding decrease in the levels of substances associated with
pain and inflammation around the area of treatment.69,70 Lowering the levels of these
proinflammatory molecules reduces the barrage of noxious input from the periphery that
cause maladaptive changes within the CNS.71 Thus, BTX may not only target the peripheral
sources of CPP but can also work in conjunction with the usual gynecologic treatments in
endometriosis to reduce peripheral and central sensitization and restore normal pain and
sensory information processing.
Conclusion
It is important to consider CPP associated with endometriosis from a global pain-centered
perspective, as MTrPs and sensitization appear to contribute significantly to the clinical
manifestations. While direct innervation of endometrial lesions may set the stage for visceral
nociception and peripheral sensitization, over time, central sensitization creates a process for
pain sustention that is independent of the initial pathology and is potentially reversible.41
Viscerosomatic convergence may not only provide the means for pain referral to somatic
structures but also govern the reflex that induces muscle spasm and the eventual formation
of MTrPs. Painful MTrPs, in turn, may serve as an additional source of nociceptive input,
and become a key component of CPP. Their deactivation through a targeted intervention may
be a critical aspect to reversing central sensitization and improving pain associated with
endometriosis.
Acknowledgments
This work was funded by the Intramural Research Program of the National Institutes of Health, the NIH Clinical
Center, and the National Institute of Neurological Disorders and Stroke.
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Fig. 1.
Nervous system engagement by endometrial lesions gives rise to different types of pain. (a)
This figure illustrates how endometrial lesions can engage the nervous system to give rise to
different types of pain associated with endometriosis and comorbid conditions. (1) Typical
laparoscopic view of pelvic organs from the umbilicus. Inset demonstrates a deeply
infiltrating lesion on the left uterosacral ligament. Both peptidergic sensory (blue) and
sympathetic nerve fibers (green) sprout axon branches (red dashed lines) toward this lesion.
Estradiol and sympathetic-sensory coupling drive peripheral sensitization (red asterisk) of
new sensory fibers within the lesion. (2) Central sensitization (red asterisk) is propagated at
synapses between sensitized peripheral nerve fibers and neurons in the sacral spine. This
central sensitization is modulated differently from and can eventually become independent
of peripherally sensitizing signals. (3) Although input from pelvic peripheral afferent fibers
typically synapse with dorsal root ganglia in the sacral spine, branches of the fibers extend to
other segments (blue dashed lines), and can propagate sensitization at distant spinal cord
segments (red dashed lines). (4) Normally, multiple intersegmental spinal synaptic
connections exist to coordinate bodily functions (double-arrowed black lines). In
pathological pain conditions, this communication can alter processing of nociceptive and
non-nociceptive sensory information in remote segments (“remote central sensitization, red
asterisks). Via (3) and (4), increased nociception propagates into distant spinal segments. (5)
Multiple afferent (blue) and efferent (green) pathways exist between the CNS and PNS with
terminal connections in the brain. Input from sensitized spinal neurons can affect activity
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throughout the neuroaxis (red asterisks), altering normal processing of nociceptive and non-
nociceptive information. Alterations in processing can occur on the medial cortical surface;
the lateral prefrontal, frontal, and parietal lobes; and within the temporal lobe (dotted black
ellipses). These influences can propagate signals independent of peripheral sensitization
associated with lesions. (b) Muscles of the pelvic floor feed into sensitization pathways in
the same manner as endometrial lesions. All mechanisms outlined can cause endometriosis-
associated pain in the pelvis and at distant sites. (Reprinted with permission from Stratton
and Berkley.3)
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Aredo et al. Page 16
Table 1
Clinical evaluation of endometriosis-related pain and sensitization
Patient History
History of endometriosis
Method of diagnosis
Previous and current treatments with their outcomes
Gynecologic and obstetric history
Menses: duration of flow, cramping, spotting, regularity, infertility, desire for future children
Gynecologic conditions, history of sexually transmitted infections
Current hormonal therapy
Surgery (type, findings, and treatment)
General medical history
Medical conditions
Headaches/migraines, depression, anxiety
Bowel and bladder symptoms suggestive of irritable bowel and painful bladder
Current medications/allergies
History of chronic pelvic pain
Duration, frequency (intermittent, constant)
Any temporal relationship to menstrual cycle (ovulation, menstruation, etc.)
Alleviating and exacerbating factors
Other pain conditions
Previous and current treatments with their outcomes
Gynecological Examination – Evoked Pain Assessment
Abdominal wall
Location and pattern of tenderness (diffuse, focal, not localized)
Allodynia
Myofascial trigger points (number, location, severity of pain)
Perineum
Improper positioning, trauma, scars
Observe pelvic floor muscle contraction and relaxation
Pelvic region
Superficial perineal muscles for muscle spasm and tenderness
Pelvic floor muscles: myofascial trigger points, taut bands, tenderness
Bladder and urethral tenderness
Uterosacral, forniceal, and vaginal tenderness and nodularity
Central uterine tenderness
Pattern of pelvic tenderness (diffuse, focal, not localized)
Location of worst pain
Neuro-Musculoskeletal Examination
Dermatome:
Allodynia via pinch and roll technique
a
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Aredo et al. Page 17
Hyperalgesia via Wartenberg pinwheel
a
Myotome
b
Regional/abdominopelvic muscles: rectus abdominis, external oblique, iliacus and gluteus maximus
General muscles: temporalis, masseter, upper trapezius, supraspinatus, adductors, vastus medialis
a
Assess spinal segments paraspinally, bilaterally in the region of pain. Record which segments have allodynia and hyperalgesia. If most segments
are affected, then add segments above and below to assess the extent of sensitization.
b
Palpate bilaterally for myofascial trigger points in region of pain and throughout the body; identify as pain free or painful (latent or active) by
region or in general. Integrate the pelvic and neuro-musculoskeletal examination findings with the clinical presentation.
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Table 2
Clinical studies evaluating botulinum toxin type A treatment for chronic pelvic pain
Study type Authors (year) NTotal BTX-A dose Areas injected Outcomes
Randomized controlled trial Abbott et al56 (2006) 60 Onabotulinum-toxin A 80 U Puborectalis and pubococcygeus
bilaterally Both treatment and placebo groups had
reductions in dyspareunia and pelvic floor
pressure BTX-A group alone showed
improved nonmenstrual pain
Petersen et al57 (2009) 64 Onabotulinum-toxin A 20 U Musculus bulbospongiosus No improvement compared with placebo at
3 and 6 mo; both treatment and placebo
groups had pain reduction at 6 mo
Prospective open-label study Ghazizadeh and
Nikzad 58 (2004) 23 Abobotulinum-toxin A 150–400 U Puborectalis at 3 points bilaterally Dyspareunia and vaginismus subjectively
improved
Jarvis et al59 (2004) 12 Onabotulinum-toxin A 40 U Puborectalis and pubococcygeus
bilaterally Dyspareunia and dysmenorrhea significantly
improved Significant reduction in resting
pelvic floor muscle pressure
Bertolasi et al60 (2009) 39 Type A toxin not otherwise specified up to 8
repeat cycles over 120 wk Levator ani Dyspareunia, levator ani hyperactivity by
EMG improved Improvements in subjective
pain, function, and quality of life by
standardized pelvic pain surveys
Nesbitt-Hawes et al61
(2012) 37 Onabotulinum-toxin A 100 U Puborectalis and pubococcygeus
bilaterally 26 women received single injection 11
women received two or more injections
Dyspareunia, nonmenstrual pelvic pain, and
vaginal pressures significantly improved in
both groups
Morrissey et al62 (2015) 21 Onabotulinum-toxin A Up to 300 U Levator ani Dyspareunia and sexual dysfunction
significantly improved Significant reduction
in pelvic floor muscle tenderness, resting
pressures, and in maximum contraction
pressures
Retrospective cohort study Adelowo et al63 (2013) 29 Onabotulinum-toxin A 100–300 U Individualized tender and
contracted points in the pelvic
floor muscles
Levator tenderness on palpation significantly
improved
Self-reported urinary incontinence decreased
significantly
Case series Romito et al64 (2004) 2 Abobotulinum-toxin A 40–80U Levator ani Complete resolution of pelvic pain and
spasm
Case report Brin and Vapnek et al65
(1997) 1 Onabotulinum-toxin A Two 10 U injections
then 40 U after 7 wk Anterior vaginal wall muscles Vaginal, bladder, and urethral spasms
subjectively improved
Thomson et al66 (2005) 1 Onabotulinum-toxin A Two 40 U injections
then two 80 U injections, ~20 wk apart Puborectalis and pubococcygeus
bilaterally Dyspareunia, dysmenorrhea, and dyschezia
improved after each injection
Reduction in pelvic floor muscle manometry
readings
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Study type Authors (year) NTotal BTX-A dose Areas injected Outcomes
Park and Paraiso67
(2009) 1 Type A toxin not otherwise specified. 40 U Levator ani and pubococcygeus Unresolved postsurgical dyspareunia
improved
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... Various physician-led clinical assessments were used to detect the presence of endometriosis-related sensitization. For instance, Aredo et al. (2017) [42] and Phan et al. (2021) [48] noted the use of a digital exam to identify active myofascial trigger points in the pelvic region as possible indicators of abdominopelvic tenderness and allodynia, which are proxies of sensitization. Somatosensory signaling from visceral and somatic organs sometimes converges on the same sensory neuron within the CNS [77] (pp. ...
... Various physician-led clinical assessments were used to detect the presence of endometriosis-related sensitization. For instance, Aredo et al. (2017) [42] and Phan et al. (2021) [48] noted the use of a digital exam to identify active myofascial trigger points in the pelvic region as possible indicators of abdominopelvic tenderness and allodynia, which are proxies of sensitization. Somatosensory signaling from visceral and somatic organs sometimes converges on the same sensory neuron within the CNS [77] (pp. ...
... Additionally, prolonged viscerosomatic convergence from pain signaling can lead to hypertrophy in skeletal muscles in the referred area, which can present itself as viscerosomatic reflexes like myofascial trigger points [79]. Aredo et al. (2017) [42] proposed examining the number and location of abdominopelvic myofascial trigger points, as well as the intensity rating of the pain elicited, as indicators of CS. Furthermore, some studies have linked the presence of active myofascial trigger points to sustained nociception and decreased pain thresholds following the removal of the initial noxious stimulus [8,79]. ...
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Background Transgender and gender diverse (TGD) people embody social and health inequalities that disproportionately affect this community more than the cisgender population. Endometriosis is a chronic condition of the reproductive tract that affects 5–10% of cisgender women. A recent systematic review with meta-analysis uncovered a pooled prevalence of 25.14% among TGD individuals undergoing gender-affirming surgeries. Objective This study aims to investigate the causes of the gap in prevalence of endometriosis between the TGD community and the cisgender population. Methods A systematic review with a fit-for-framework analysis was conducted. Results were analysed according to the adjusted developmental framework for embodiment with an intersectional approach. Sources were categorised in multi-levels relating to the framework mechanisms of expression, shaping, interaction, and incorporation. Results Four hundred twenty-three (423) studies published between 2001 and 2024 in English and Spanish were identified on the PubMed, Web of Science, Sociological abstracts, and PsycInfo databases. Thirty-two (32) peer-reviewed sources were selected. Discussion The higher prevalence of endometriosis among TGD people compared to the cisgender population reflects a complex phenomenon whereby individual biomedical characteristics, and psychological and environmental factors interplay on multiple levels throughout one’s lifespan. The prevalence gap is striking in a context where TGD people experience great barriers and delays to access healthcare, and endometriosis is typically understood as a “women’s disease.” TGD people express lifestyle and environmental factors correlated with endometriosis more often than cisgender women, such as history of trauma, low self-image, obesity. Endometriosis interacts with one’s quality of life, and especially with gendered expectations related to menstruations, family planning and sexuality. This interference can result in biographical disruption and gender self-perception changes in both cisgender and TGD people. Exogenous testosterone use as gender-affirming therapy results in amenorrhea in 80% of cases. However, endometrium and follicular activities are still reported upon testosterone use suggesting endometriosis may be active. It is hypothesised that testosterone use could lead to a hyper-estrogenic state that would stimulate endometriosis proliferation.
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Objective The primary objective of this study was to describe referral patterns to an interdisciplinary CPP clinic at a tertiary care center. Study design This was a retrospective cohort study of female patients assigned an ICD-10 code diagnosis related to chronic pelvic pain at a tertiary care referral center between January 2017 and December 2019. Electronic medical records were queried for patient and clinician characteristics. The rate of referral to this clinic was determined based on the data collected, and patient and provider factors associated with referral were assessed using logistic regression analyses. Results Of the 732 patients identified, 25.9% ( n = 190, 95% CI = [22.9%,29.3%]) received a referral to an interdisciplinary CPP clinic. Logistic regression analyses significantly revealed multiple factors associated with referral: number of previous treatment modalities used (adjusted OR [aOR] = 1.76 per treatment 95% CI = [1.48, 2.10], p < 0.001), distance to the treatment center (aOR = 0.48 [0–25 miles vs 25–60 miles] 95% CI = [0.31, 0.74], p < 0.001), IBS diagnosis (aOR = 1.67 95% CI = [1.02, 2.74], p = 0.044), endometriosis diagnosis (aOR = 1.63 95% CI = [1.06, 2.52], p = 0.026), as well as a psychiatric diagnosis (aOR = 1.46 95% CI = [1.00, 2.12], p = 0.048). Physicians were less likely to make a referral compared to Advanced Practice Providers (aOR = 0.38 95% CI = [0.22, 0.65], p < 0.001). Conclusion Approximately one in four patients with a diagnosis of CPP were referred to our interdisciplinary clinic. Several patient factors were associated with referral. These data show a need for education about the existence of this type of center.
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Background The diagnosis of neuromuscular pelvic pain is challenging. Despite the increasing use of magnetic resonance imaging (MRI) in the assessment of pudendal neuralgia, there are limited data describing radiological variations of the nerve. Additionally, the utility of MRI in the assessment of pelvic floor tension myalgia is unknown. Aims To describe the anatomical variations of the pudendal nerve and dimensions of pelvic muscles in patients investigated for neuromuscular pelvic pain using a combined MRI protocol. Materials and methods A retrospective audit of MRI reports for 136 patients referred to a single radiologist was conducted. Reported data included the appearances of the pudendal nerve and its perineural structures, and the maximal thicknesses of pelvic muscles. Results Several anatomical variations were identified in the course of the pudendal nerve at or above the ischial spine. Likely/highly likely nerve compression at this level was present in 34.6% of hemipelves. Variations associated with compression included delayed separation of the sacrospinous and sacrotuberous ligaments ( p < 0.0001), close apposition of ligaments ( p < 0.0001), interligamentous bands ( p = 0.033), coccygeal muscle contributions to the sacrospinous ligament ( p = 0.014) and proximal ( p < 0.0001) and thickened falciform ligaments ( p < 0.0001). Variations below the ischial spine were uncommon. Conclusions This study represents a quantitative and qualitative expansion to the radioanatomical basis of pudendal nerve entrapment on MRI, and highlights the limitations of MRI obtaining reproducible measurements of pelvic muscles. Images from asymptomatic controls and further prospective evaluation of treatment outcomes is required to determine the clinical significance of MRI findings in the assessment of pudendal neuralgia.
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Recent research has proven that peripheral (PS) and central sensitization (CS), mental health, and myofascial dysfunction all play a role, alongside nociception, in the genesis and in the perpetuation of endometriosis’ symptoms. However, such components of pain are still largely ignored in clinical practice, although not considering such contributors may entail serious consequences on women’s health, including the choice of unnecessary surgery and leaving the real causes of pain untreated. At the present time, we are facing a paradox by which 25–40% of women who undergo laparoscopic surgery for pelvic pain do not have an obvious diagnosis, while the percentage of women with endometriosis who have signs of CS, of depressive or anxiety disorders, or who have an increased pelvic muscle tone ammounts to 41–55%, 15–88% and 28–73%, respectively. Moving from the widely-accepted stepwise approach suggested for endometriosis management, which consists in the initial prescription of low-dose combined oral contraceptives (COCs) or of a progestin monotherapy, followed by GnRH analogues and, ultimately, by surgery, when COCs and progestins have proven ineffective or are not tolerated or contraindicated, we propose an integration of such model which takes into account the identification and the simultaneous treatment of all pain contributors. Our objective is to encourage physicians’ awareness of the need of a multidisciplinary, multimodal approach to endometriosis-related pain, and ultimately to promote a reduction in the number of unnecessary surgeries.
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The purpose of this review is to consider current ideas about psychophysiology of chronic pelvic pain (CPP) in external genital endometriosis (GE), as well as the impact of the psychoemotional state and sexual function in women with CPP on its development and maintenance. The review is based on the study of original Russian and English-language articles and our own extensive clinical experience. References are made to statistically reliable, randomized and placebo-controlled studies of the last 20 years, in some cases to small and open-ended studies indicating their low evidence. The analysis shows a variety of opinions on this issue united by an understanding of the promising role of a biopsychosocial approach to the diagnosis and treatment of CPP in GE. Further studies of the role of psychosocial factors in the development of CPP are needed, as well as an assessment of the effectiveness of a comprehensive multidisciplinary approach to the treatment of CPP and associated sexual dysfunctions.
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Primary dysmenorrhea (PD), a prevalent menstrual condition characterized by pelvic pain during the menstrual cycle, significantly impacts the quality of life of women and produces increased pain sensitivity that can persist throughout the menstrual cycle. However, scientific literature has not studied whether there are implications for alterations in muscle function and endurance in the abdominopelvic region during the non-painful phases of the menstrual cycle. The aim of this study was to compare muscle function and endurance capacity in the abdominopelvic region in women with PD versus women without this condition. An observational, cross-sectional study was designed to analyze muscle activation and endurance capacity using electromyography (EMG) during McGill exercises. Forty-four women were included, 22 with PD and 22 without dysmenorrhea. The results did not indicate significant differences in muscle activation and endurance of the abdominopelvic musculature between the two groups (p > 0.05). However, the analysis suggests that women with primary dysmenorrhea might develop compensatory strategies that allow them to maintain physical function despite their condition. These results suggest that the approach to PD could focus more on pain management rather than physical functionality, and more studies are needed from a comprehensive approach to more accurately evaluate the relationship between PD and muscle function.
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Objective: Botulinum toxin injection has been applied for pain relief in various chronic pain syndromes. Recently, systematic review studies reported inconclusive effects of Botulinum toxin in myofascial pain management. The present study aimed to demonstrate the efficacy and safety of Botulinum toxin type A (BTxA) (Botox®) injection for pain reduction in myofascial trigger point (MTrP) of the upper trapezius muscle. Material and Method: Thirty-three patients with 48 MTrP on the upper trapezius muscles over three months with moderate to severe pain intensity diagnosed at physical medicine and rehabilitation outpatient department were recruited between December 2011 and March 2012. Eligible patients were blinded and randomly injected with single 0.2 ml (20 IU) of BTxA for 24 MTrP and 0.2 ml of 0.9% NaCl solution for 24 MTrP at the most tender trigger point on the upper trapezius muscle. All patients were advised for stretching exercise and ergonomic adaptation throughout the study. At 3- and 6-week after injections, visual analogue scale (VAS), the pressure pain threshold (PPT), and reported adverse effects were measured. Results: Both BTxA and control groups demonstrated statistically significant differences in VAS reduction and increased PPT after 3 weeks and 6 weeks compared with before treatment. There were no statistically significant differences in VAS reduction from baseline between the two groups at 3- and 6-week after treatment. A statistically significant difference in improvement of PPT from baseline and 6-week after BTxA injection compared with 0.9% NaCl group was shown (1.0±0.9 and 0.5±0.7, p = 0.036). There was mild degree side-effects that spontaneous resolved within one week in both groups without significant difference in percentage. No severe adverse effects were reported during the study. Conclusion: The efficacy in VAS reduction of a single 20 IU of Botulinum toxin type A (Botox®) injection was not different from 0.9% NaCl for myofascial trigger point at the upper trapezius muscle. However, Botulinum toxin type A (Botox®) showed statistically significant more increased in pressure pain threshold at 6-week after injection without severe adverse effects.
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Background: Chronic pelvic pain is a common condition among women, and 10 to 30 % of causes originate from the abdominal wall, and are associated with trigger points. Although little is known about their pathophysiology, variable methods have been practiced clinically. The purpose of this study was to evaluate the efficacy of local anaesthetic injections versus ischemic compression via physical therapy for pain relief of abdominal wall trigger points in women with chronic pelvic pain. Methods: We conducted a parallel group randomized trial including 30 women with chronic pelvic pain with abdominal wall trigger points. Subjects were randomly assigned to one of two intervention groups. One group received an injection of 2 mL 0.5 % lidocaine without a vasoconstrictor into a trigger point. In the other group, ischemic compression via physical therapy was administered at the trigger points three times, with each session lasting for 60 s, and a rest period of 30 s between applications. Both treatments were administered during one weekly session for four weeks. Our primary outcomes were satisfactory clinical response rates and percentages of pain relief. Our secondary outcomes are pain threshold and tolerance at the trigger points. All subjects were evaluated at baseline and 1, 4, and 12 weeks after the interventions. The study was conducted at a tertiary hospital that was associated with a university providing assistance predominantly to working class women who were treated by the public health system. Results: Clinical response rates and pain relief were significantly better at 1, 4, and 12 weeks for those receiving local anaesthetic injections than ischemic compression via physical therapy. The pain relief of women treated with local anaesthetic injections progressively improved at 1, 4, and 12 weeks after intervention. In contrast, women treated with ischemic compression did not show considerable changes in pain relief after intervention. In the local anaesthetic injection group, pain threshold and tolerance improved with time in the absence of significant differences between groups. Conclusion: Lidocaine injection seems to be better for reducing the severity of chronic pelvic pain secondary to abdominal wall trigger points compared to ischemic compression via physical therapy. Trial registration: ClinicalTrials.gov NCT00628355. Date of registration: February 25, 2008.
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Current evidence suggests that botulinum neurotoxins (BoNTs) A1 and B1, given locally into peripheral tissues such as skin, muscles, and joints, alter nociceptive processing otherwise initiated by inflammation or nerve injury in animal models and humans. Recent data indicate that such locally delivered BoNTs exert not only local action on sensory afferent terminals but undergo transport to central afferent cell bodies (dorsal root ganglia) and spinal dorsal horn terminals, where they cleave SNAREs and block transmitter release. Increasing evidence supports the possibility of a trans-synaptic movement to alter postsynaptic function in neuronal and possibly non-neuronal (glial) cells. The vast majority of these studies have been conducted on BoNT/A1 and BoNT/B1, the only two pharmaceutically developed variants. However, now over 40 different subtypes of botulinum neurotoxins (BoNTs) have been identified. By combining our existing and rapidly growing understanding of BoNT/A1 and /B1 in altering nociceptive processing with explorations of the specific characteristics of the various toxins from this family, we may be able to discover or design novel, effective, and long-lasting pain therapeutics. This review will focus on our current understanding of the molecular mechanisms whereby BoNTs alter pain processing, and future directions in the development of these agents as pain therapeutics.
Book
This important book fills a need in the developing area of Pain Medicine, providing physicians with an up-to-date resource that would detail the current understanding about the basic science underlying the mechanism of action of the various CAM therapies used for pain, summarizing the clinical evidence both for efficacy and safety, and then end with practical guidelines about how such treatments could be successfully and safely integrated into a Pain practice.
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High-tone pelvic floor dysfunction (HTPFD) is a debilitating chronic pain disorder for many women with significant impact on their quality of life (QoL). Our objective was to determine the efficacy of electromyography-guided onabotulinumtoxinA (Botox; Allergan, Irvine, Calif) injections in treating patient's perception of pelvic pain and improving QoL measurement scores. This is a prospective pilot open-label study of women with chronic pelvic pain and HTPFD who have failed conventional therapy between January 2011 and August 2013. Botox injections (up to 300 U) were done using needle electromyography guidance, from a transperineal approach, to localize spastic pelvic floor muscles (PFMs). Data were collected at baseline, 4, 8, 12, and 24 weeks after injections. This included demographics; Visual Analog Scale (VAS) scores for pain and dyspareunia; validated questionnaires for symptoms, QoL, and sexual function; Global Response Assessment scale for pelvic pain; digital examination of PFM for tone and tenderness; and vaginal manometry. Side effects were also recorded. Out of 28 women who enrolled in the study, 21 completed the 6-month follow-up and qualified for analysis. The mean (SD) age was 35.1 (9.4) years (range, 22-50 years), and the mean (SD) body mass index was 25 (4.4). Comorbidities included interstitial cystitis/bladder pain syndrome (42.9%) and vulvodynia (66.7%). Overall, 61.9% of subjects reported improvement on Global Response Assessment at 4 weeks and 80.9% at 8, 12, and 24 weeks post injection, compared with baseline. Of the subjects who were sexually active at baseline, 58.8% (10/17), 68.8% (11/16), 80% (12/15), and 83.3% (15/18) reported less dyspareunia at 4, 8, 12, and 24 weeks, respectively. Dyspareunia Visual Analog Scale score significantly improved at weeks 12 (5.6, P = 0.011) and 24 (5.4, P = 0.004) compared with baseline (7.8). Two of the 4 patients who avoided sexual activity at baseline secondary to dyspareunia resumed and tolerated intercourse after Botox. Sexual dysfunction as measured by the Female Sexual Distress Scale significantly improved at 8 weeks (27.6, P = 0.005), 12 weeks (27.9, P = 0.006), and 24 weeks (22.6, P < 0.001) compared with baseline (34.5). The Short-Form 12 Health Survey (SF-12) showed improved QoL in the physical composite score at all post injections visits (42.9, 44, 43.1, and 45.5 vs 40 at baseline; P < 0.05), and in the mental composite score at both 12 and 24 weeks (44.3 and 47.8 vs 38.5, P = 0.012). Vaginal manometry demonstrated significant decrease in resting pressures and in maximum contraction pressures at all follow-up visits (P < 0.05). Digital assessment of PFM (on a scale from 0 to 4) showed decreased tenderness on all visits (mean of 1.9, 1.7, 1.8, 1.9; P < 0.001) compared with baseline (2.8). Reported postinjection adverse effects included worsening of the following preexisting conditions: constipation (28.6%), stress urinary incontinence (4.8%), fecal incontinence (4.8%), and new onset stress urinary incontinence (4.8%). Electromyography-guided Botox injection into PFM could be beneficial for women with refractory HTPFD who have failed conservative therapy.
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The intent of this paper is to discuss the evolving role of the myofascial trigger point (MTrP) in myofascial pain syndrome (MPS) from both a historical and scientific perspective. MTrPs are hard, discrete, palpable nodules in a taut band of skeletal muscle that may be spontaneously painful (i.e. active), or painful only on compression (i.e. latent). MPS is a term used to describe a pain condition which can be acute or, more commonly, chronic and involves the muscle and its surrounding connective tissue (e.g. fascia). According to Travell and Simons, MTrPs are central to the syndrome-but are they necessary? Although the clinical study of muscle pain and MTrPs has proliferated over the past two centuries, the scientific literature often seems disjointed and confusing. Unfortunately, much of the terminology, theories, concepts, and diagnostic criteria are inconsistent, incomplete, or controversial. In order to address these deficiencies, investigators have recently applied clinical, imaging (of skeletal muscle and brain), and biochemical analyses to systematically and objectively study the MTrP and its role in MPS. Data suggest that the soft tissue milieu around the MTrP, neurogenic inflammation, sensitization, and limbic system dysfunction may all play a role in the initiation, amplification, and perpetuation of MPS. The authors will chronicle the advances that have led to the current understanding of MTrP pathophysiology and its relationship to MPS, and review the contributions of clinicians and researchers who have influenced and expanded our contemporary level of clinical knowledge and practice. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Article
To evaluate sensitization, myofascial trigger points, and quality of life in women with chronic pelvic pain with and without endometriosis. A cross-sectional prospective study of women aged 18-50 years with pain suggestive of endometriosis and healthy, pain-free volunteers without a history of endometriosis. Patients underwent a physiatric neuromusculoskeletal assessment of clinical signs of sensitization and myofascial trigger points in the abdominopelvic region. Pain symptoms, psychosocial, and quality-of-life measures were also assessed. All participants with pain underwent laparoscopic excision of suspicious lesions to confirm endometriosis diagnosis by histologic evaluation. Patients included 18 with current, biopsy-proven endometriosis, 11 with pain only, and 20 healthy volunteers. The prevalence of sensitization as measured by regional allodynia and hyperalgesia was similar in both pain groups (83 and 82%) but much lower among healthy volunteers (15%, P<.001). Nearly all women with pain had myofascial trigger points (94 and 91%). Adjusting for study group, those with high anxiety (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.004-1.099, P=.031) and depression (OR 1.06, 95% CI 1.005-1.113, P=.032) scores were more likely to have sensitization. Pain patients with any history of endometriosis had the highest proportion of sensitization compared with the others (87% compared with 67% compared with 15%; P<.001). Adjusting for any history of endometriosis, those with myofascial trigger points were most likely sensitized (OR 9.41, 95% CI 1.77-50.08, P=.009). Sensitization and myofascial trigger points were common in women with pain regardless of whether they had endometriosis at surgery. Those with any history of endometriosis were most likely to have sensitization. Traditional methods of classifying endometriosis-associated pain based on disease, duration, and anatomy are inadequate and should be replaced by a mechanism-based evaluation, as our study illustrates. ClinicalTrials.gov, www.clinicaltrials.gov, NCT00073801. LEVEL OF EVIDENCE:: II.
Article
To determine the prevalence of myofascial pain and the outcome of transvaginal pelvic floor physical therapy for the treatment of chronic pelvic pain caused by myofascial pelvic pain in a tertiary care facility. A retrospective chart review was performed on all women who presented to our facility between January 2005 and December 2007. Those diagnosed with myofascial pelvic pain and referred for transvaginal pelvic floor physical therapy over this 3-year period were evaluated. Participants with an initial pain score of > or = 4, myofascial pelvic pain on examination, and who attended 2 or more physician visits were included in the analysis. Patient physical examination findings, symptoms, and verbal pain ratings were reviewed. In all, 146 (13.2%) of 1,106 initially screened patients were diagnosed with myofascial pain. Seventy-five (51%) of the 146 patients who were referred for physical therapy were included, and 75% had an initial pain score of > or = 7. Pain scores significantly improved proportional to the number of physical therapy visits completed, with 63% of patients reporting significant pain improvement. Transvaginal physical therapy is an effective treatment for chronic pelvic pain resulting from myofascial pelvic pain.
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Clinical management of endometriosis is limited by the complex relationship between symptom severity, heterogeneous surgical presentation, and variability in clinical outcomes. As a complement to visual classification schemes, molecular profiles of disease activity may improve risk stratification to better inform treatment decisions and identify new approaches to targeted treatment. We use a network analysis of information flow within and between inflammatory cells to discern consensus behaviors characterizing patient subpopulations. Unsupervised multivariate analysis of cytokine profiles quantified by multiplex immunoassays identified a subset of patients with a shared "consensus signature" of 13 elevated cytokines that was associated with common clinical features of endometriosis, but was not observed among patient subpopulations defined by morphologic presentation alone. Enrichment analysis of consensus markers reinforced the primacy of peritoneal macrophage infiltration and activation, which was demonstrably elevated in ex vivo cultures. Although familiar targets of the nuclear factor κB family emerged among overrepresented transcriptional binding sites for consensus markers, our analysis provides evidence for an unexpected contribution from c-Jun, c-Fos, and AP-1 effectors of mitogen-associated kinase signaling. Their crucial involvement in propagation of macrophage-driven inflammatory networks was confirmed via targeted inhibition of upstream kinases. Collectively, these analyses suggest a clinically relevant inflammatory network that may serve as an objective measure for guiding treatment decisions for endometriosis management, and in the future may provide a mechanistic endpoint for assessing efficacy of new agents aimed at curtailing inflammatory mechanisms that drive disease progression.