Study of Possible Changes in QST After Application of Capsaicin on Patients With Peripheral Neuropathic Pain

Kind and Duration of Possible Changes of the Sensory Profiles After the Topical Application of Capsaicin (8%) in Patients With Peripheral Neuropathic Pain

The treatment of neuropathic pain ist still a challenge. A new promising therapy is the use of capsaicin on skin.

The investigators first experiences with capsaicin in patients with peripheral nerve injury showed changes in the sensibility, which achieved its maximal extent after four weeks and was regressive, but not completely abolished 1,5 months after application.

In this study the investigators hope to specify, how long and in which way exactly this changes in sensibility appear.

Study Overview

• Status: Completed
• Conditions: Postherpetic Neuralgia; Peripheral Nerve Injury
• Intervention / Treatment: Procedure: quantitative sensory testing (QST)

Detailed Description

The topical application of a high dosage of capsaicin (8%) is a new promising approach. There is only little knowledge about the extent and the duration of drug-induced changes of detection and pain thresholds based on a currently recommended standardized quantitative sensory testing (QST). The assessment of QST changes would be an important step forward to understand the way of action as well as the time course of the presumed recovering of the C-fiber function after topical application of a high concentration capsaicin patch.

10 patients suffering from peripheral neuropathic pain due to peripheral nerve injury and 10 patients suffering from postherpetic neuralgia will be investigated by QST following the protocol of DFNS (German Research Network on Neuropathic Pain), using both thermal and mechanical nociceptive as well as non-nociceptive stimuli.

QST will be performed at the following times:

• at baseline
• 2, 4, 6, 8 weeks later, and every two weeks at least until re-occurrence of pain and/or recovering of the capsaicin-induced worsening of the C-fiber function.

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• Germany
  • Bochum, Germany
    • Bergmannsheil, department for pain management

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

proved peripheral neuropathy (e.g. peripheral nerve lesion, postherpetic neuralgia)

Description

Inclusion Criteria:

• age >18 years with signed informed consent
• with planned topical application of capsaicin (8%) and with no involvement in any other study
• with neurological proved peripheral neuropathy (e.g. peripheral nerve lesion, postherpetic neuralgia) and with remaining moderate pain intensity under the current treatment (> NRS 3; numeric rating scale 0-10)
• some remaining sensory function at the baseline QST with z-scores ≥ - 3 for cold, warmth and tactile thresholds

Exclusion Criteria:

• with missing informed consent
• with any contraindications for capsaicin application
• with diabetes mellitus,
• using lidocaine patch in the test area in the last 6 months before enrollment
• with inadequate knowledge of the german language

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
patients with peripheral nerve injury; 10 patients with neuropathic pain, because of peripheral nerve injury will obtain a baseline-QST and after capsaicin-application a QST 2, 4, 6, 8 and every 2 weeks until re-occurrence of pain and/or recovery of the capsaicin-induced sensory deficits	Procedure: quantitative sensory testing (QST); with QST the small-fibre function is tested by registering thermal and mechanical thresholds, so that changes in the sensory profile can by specified
patients with postherpetic neuralgia; 10 patients with neuropathic pain, because of postherpetic neuralgia will obtain a baseline-QST and after capsaicin-application a QST 2, 4, 6, 8 and every 2 weeks until re-occurrence of pain and/or recovery of the capsaicin-induced sensory deficits	Procedure: quantitative sensory testing (QST); with QST the small-fibre function is tested by registering thermal and mechanical thresholds, so that changes in the sensory profile can by specified

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of the functional loss of the C- and A-delta-fibres after therapeutic application of capsaicin 8% as measured by the impairment of the thermal thresholds	measurement of thermal detection thresholds for warmth (WDT) and cold (CDT) by QST (standard DFNS protocol), change of z-values for WDT and CDT from baseline to 8 weeks after capsaicin-application (ANOVA)	8 weeks after capsaicin-patch (8%) application
Extent of the functional loss of the C- and A-delta-fibres after therapeutic application of capsaicin 8% as measured by the impairment of the thermal thresholds	measurement of thermal detection thresholds for warmth (WDT) and cold (CDT) by QST (standard DFNS protocol), change of z-values for WDT and CDT from baseline to 8 weeks after capsaicin-application (ANOVA)	8 weeks after capsaicin-patch (8%) application

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Decrease of thermal Hyperalgesia	change of thermal hyperalgesia measured by QST (z-value of heat pain and cold pain threshold)from baseline to 8 weeks after capsaicin-application	8 weeks after capsaicin-patch (8%) application
Decrease of mechanical hyperalgesia	change of mechanical hyperalgesia measured by QST (z-value of mechanical pain threshold and mechanical pain sensitivity) from baseline to 8 weeks after capsaicin-application	8 weeks after capsaicin-patch (8%) application
Decrease of dynamical mechanical allodynia	change of dynamical mechanical allodynia measured by QST from baseline to 8 weeks after capsaicin-application	8 weeks after capsaicin-patch (8%) application
Correlation of efficacy on the sensory function and the reported soothing of symptoms after capsaicin-application	comparison of z-values for cold, warmth and mechanical detection threshold to the outcome of the german versions of the following questionnaires: PainDETECT, NPSI (Neuropathic Pain Symptom Inventory) and Patient's global impression of change (PGIC), analyzed by ANCOVA	8 weeks after application of capsaicin-patch (8%)

Collaborators and Investigators

• Sponsor: Ruhr University of Bochum
• Investigators: Study Director: Christoph Maier, Prof.Dr.med, University hospital Bergmannsheil department of pain management

Study record dates

Study Major Dates

• Study Start: April 1, 2011
• Primary Completion (Actual): November 1, 2012
• Study Completion (Actual): November 1, 2012

Study Registration Dates

• First Submitted: February 23, 2012
• First Submitted That Met QC Criteria: May 9, 2012
• First Posted (Estimate): May 11, 2012

Study Record Updates

• Last Update Posted (Estimate): December 20, 2012
• Last Update Submitted That Met QC Criteria: December 19, 2012
• Last Verified: December 1, 2012

More Information

Terms related to this study

• Keywords: neuropathic pain; postherpetic neuralgia; PHN; peripheral nerve injury; PNI; Capsaicin; QST; quantitative sensory testing; sensory profile
• Additional Relevant MeSH Terms: Nervous System Diseases; Pain; Neurologic Manifestations; Wounds and Injuries; Neuromuscular Diseases; Peripheral Nervous System Diseases; Trauma, Nervous System; Neuralgia; Neuralgia, Postherpetic; Peripheral Nerve Injuries
• Other Study ID Numbers: Capsaicin2011

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No