Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT03228160 |
| Other study ID # |
N201511030 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 1, 2016 |
| Est. completion date |
December 31, 2024 |
Study information
| Verified date |
May 2022 |
| Source |
Taipei Medical University Shuang Ho Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Background. Sympathetically maintained pain (SMP) can be effectively relieved by light
irradiation to the area near stellate ganglion (SGI), which is applied as an alternative to
sympathetic blockade. The clinical efficiency of SGI on heart rate variability (HRV) and its
association with pain outcome need to be further identified.
Objectives. This study is aimed to identify the effects of SGI on pain, HRV indices, quality
of life, and function outcomes.
Design. A prospective, double blind, randomized designed study Setting. An outpatient pain
medicine clinic Subjects and Methods. A total of 44 patients will be enrolled and randomized
to their allocations: the experimental group (EG, n=22) and control group (CG, n=22). All
patients in EG will receive 12 sessions (twice a week) of standard SGI, while those in CG go
through the same protocol except a shame irradiation is applied. Pain, HRV variables, quality
of life, and function outcoms are measured before and after SGI in each session. All measures
at the first-half and second-half courses are analyzed.
Description:
Sympathetically maintained pain (SMP) is defined as an aspect of pain which is maintained or
mediated by sympathetic efferent activity including the action of circulating catecholamine
and is often linked to the complex regional pain syndrome (CRPS). SMP has been categorized as
a subset of neuropathic pain mediated by the underlying mechanism of peripheral sensitization
referring to noradrenergic sensitization of peripheral afferent nociceptive fibers and a
pathologically sympathetic-sensory coupling interaction between the efferent sympathetic and
the afferent system. Besides, SMP is associated with vasomotor and sudomotor dysfunction
through either peripheral integerized by an adrenoreceptor stimulated or central organized by
sensitization. Therefore, modulation of sympathetic activity either by means of
pharmacological analgesics or local sympathetic ganglion blockade may influence the pain
course in patients with chronic pain and hyperalgesia that were suspected to be
sympathetically maintained.
The pain associated with sympathetic activity can be relieved by blockage of efferent
sympathetic nerves to the affected area. Stellate ganglion block (SGB), a local anesthetic
blockade of sympathetic ganglia, has been advocated as an early intervention to achieve
sympatholysis and its strong evidence had been identified. However, a success of SGB depends
on the skilled invasive technique in application and several potential complications may be
elucidated. Alternatively, the light irradiation near the stellate ganglion region (SGI)
using either low-reactive level laser or linear-polarized near-infrared light irradiation had
been used as a noninvasive method for local anesthetic sympathetic blockade. Furthermore, SGI
can be safely and conveniently performed in clinical practice even when an anesthetic
physician is not available, had been well tolerated by patients, and no thermal injury or
side effects were reported by literatures.
SGI had been identified to offer similar effects of SGB for patients with neuropathic pain,
including improving blood flow by dilating vessels and reducing pain by directly blocking
afferent nociceptive signal traveling via sympathetic pathways. The irradiation effect on
heart rate variability (HRV), which is an objectively non-invasive marker of the autonomic
nervous system, had not yet been well established. If the pathogenesis of SMP is closely
referred to some abnormality in the function of autonomic nerve system (ANS), it is more
necessary to measure autonomic activity for validation rather than pain status, local
temperature or peripheral blood flow. Whether the relieved pain level after SGI is associated
to HRV changes remains unclear. Identifying the relationship between HRV and pain status
following SGI allows the clinicians to set a prompt protocol of phototherapy using SGI, and
to accurately follow the outcome of autonomic dysfunction in patients with SMP.
The purpose of this study was to demonstrate the sympatholytic and clinical effects of linear
polarized near-infrared irradiation applied on stellate ganglion in patients with SMP.
An experimental design with two groups will be used and a double blind, prospective
randomized control trial will be conducted at the chronic pain medicine center in the
physical medicine and rehabilitation department. Potential patients will be recruited. The
enrolled patients will be randomly assigned to the experimental group or the control group
(CG) using a table of random numbers. Patients in the experimental group will receive a
6-week standard SGI treatment protocol (12 irradiation sessions), while those in the control
group being undergo a sham irradiation during the same period. Both the investigators and the
patients will be blinded to the group assignments. All outcome measures will be collected by
a trained research assistant at the baseline admission prior to SGI therapy, before and after
SGI at each irradiation session, and at the follow up admission immediately after the end of
6-week treatment period.
