The Significance of Peripheral Input

Neuropathic Pain Clinical Trial

Official title:

The Significance of Peripheral Input in Patients With Post Surgery Neuropathic Pain: Evaluation of Trigger Point Anesthesia. A Double-blind, Randomized, Controlled Exploratory Study

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04764045
• Other study ID #: NP-FM-19
• Status: Recruiting
• Phase: N/A
• Start date: November 20, 2019
• Est. completion date: May 1, 2021

Study information

• Verified date: February 2021
• Source: Bispebjerg Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The investigators want to examine trigger point injections of local anesthetics, in patients with post operative neuropathic pain, determine changes in sensory disturbances such as allodynia, hyperalgesia and thermal sensitivity and examine whether trigger point injections will attenuate pain in rest and activity.

Description:

The presence of cutaneous trigger points in the surgical incision of patients with post-surgery pain has been shown in our pain clinic, all patients have persistent pain for more than 3 month and different sensory disturbances.

Examinations with trigger point injections of local anesthetics have been used to determine the influence of peripheral changes and the significance of afferent input on persistent post-surgery neuropathic pain.

In the present study the investigators will document the influence of cutaneous trigger point injections for both subjective pain experience and objective findings in the area such as allodynia, hyperalgesia and thermal sensitivity. The investigators expect reduction in spontaneous pain intensity and de-crease in peripheral sensory disturbances and will determine the significance of peripheral input in persistent neuropathic pain.

The investigators aim to investigate whether injection of local anesthesia into trigger points compared with placebo (saline) injection will attenuate pain and normalize abnormal sensations, such as hyperalgesia and allodynia. The investigators believe this to be an important investigation to understand the mechanisms behind chronic post-surgery pain.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 12
• Est. completion date: May 1, 2021
• Est. primary completion date: May 1, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age > 18 years old

• Patients with chronic pain (daily VAS pain scores >30 mm) for at least 3 months after knee, shoulder or foot surgery

• Patients with at least one identifiable trigger point in relation to incision from the knee, shoulder or foot surgery. A trigger point is defined as an ar-ea in relation to the incision from surgery, in which a light pressure from a cotton pin radiate pain to the nearby area, and exudes a motor reflex causing withdrawal of the leg

• A written informed consent to participate in the study after having fully understood the contents of the protocol and restrictions

Exclusion Criteria:

• Patients who cannot cooperate

• Patients who cannot understand or speak Danish.

• Patients with allergy to the drugs used in the study

• Patients in treatment with vitamin K antagonists.

• Patients with other pain conditions

• Patients with diabetes

Related Conditions & MeSH terms

• Neuralgia
• Neuropathic Pain

Intervention

Drug:
• Ropivacaine
Injection of 1 ml Ropivacaine in all trigger points in and around scar. Injection of 1 ml saline in all trigger points in and around scar.

Locations

Country	Name	City	State
Denmark	Bispebjerg Hospital	Copenhagen

Sponsors (1)

Lead Sponsor	Collaborator
Bispebjerg Hospital

Country where clinical trial is conducted

Denmark, 

References & Publications (3)

Haroutounian S, Ford AL, Frey K, Nikolajsen L, Finnerup NB, Neiner A, Kharasch ED, Karlsson P, Bottros MM. How central is central poststroke pain? The role of afferent input in poststroke neuropathic pain: a prospective, open-label pilot study. Pain. 2018 Jul;159(7):1317-1324. doi: 10.1097/j.pain.0000000000001213. — View Citation

Haroutounian S, Nikolajsen L, Bendtsen TF, Finnerup NB, Kristensen AD, Hasselstrøm JB, Jensen TS. Primary afferent input critical for maintaining spontaneous pain in peripheral neuropathy. Pain. 2014 Jul;155(7):1272-1279. doi: 10.1016/j.pain.2014.03.022. Epub 2014 Apr 2. — View Citation

Wijayasinghe N, Ringsted TK, Bischoff JM, Kehlet H, Werner MU. The role of peripheral afferents in persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled, crossover trial of ultrasound-guided tender point blockade. Br J Anaesth. 2016 Jun;116(6):829-37. doi: 10.1093/bja/aew071. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in worst pain in rest and in activity	Change in worst pain assessed on a visual analogue scale (VAS, 0-100 mm) at rest and after stair walking/abduction of shoulder, before and after trigger point injections compared to baseline pain score	30 minutes
Secondary	Change in area of sensory disturbances	Area of pin-prick hyperalgesia, using von Frey filament 60 g and brush allodynia, using Somdic brush, assessed pre- and post-injection. Areas identified at a control day between the two intervention days.	30 minutes
Secondary	Change in warm and cold detection, threshold and tolerance before and after intervention in area with hyperalgesia compared to normal skin	Detection, thresholds and tolerance for cold and heat within the hyperalgesia area compared to normal skin at the contralateral site, before and after trigger point injections. All measures made with Somedic MSA Thermal Stimulator	30 minutes