Two Point Discrimination

Low Back Pain Clinical Trial

— TPD  

Official title:

Retuning the Nervous System in Youth With Chronic Pain

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03686748
• Other study ID #: CIN_TPD_001
• Status: Recruiting
• Phase: Early Phase 1
• Start date: July 21, 2018
• Est. completion date: July 16, 2023

Study information

• Verified date: January 2020
• Source: Children's Hospital Medical Center, Cincinnati
• Contact: Geraldine C Schulze
• Phone: 513-978-3007
• Email: geraldine.schulze[@]cchmc.org
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

SPECIFIC AIMS

Pain in both youth and adults is a complex, subjective and personal experience, and remains poorly understood. One particularly perplexing dimension of some forms of pain is the tendency of pain to spread outside of an affected body site to adjacent location, and then to unaffected body sites. Such widespread pain may reflect an altered spatial tuning of somatosensory processing, such that lateral inhibition is diminished, thereby allowing pain to spread. To date, no therapies exist which are designed specifically to diminish or even reverse the spatial spread of pain. However, training in two-point discrimination holds the potential to retune spatial aspects of somatosensory processing and may represent a novel therapy for widespread pain. Thus, the present investigation will test the following aims:

Aim 1. Do youth with chronic pain have disrupted spatial tuning of somatosensory processing? Deficits in two point tactile discrimination have long been noted in adults with chronic pain, but such deficits remain poorly documented in pediatric chronic pain patients. In order to determine if such deficits exist, youth with both chronic pain and healthy youth will undergo assessment of two point discrimination thresholds.

Aim 2. Does two-point discrimination training result in diminished pain and disability in youth with somatic pain? After initial characterization of tactile discrimination thresholds, youth with chronic pain will participate in multiple sessions of either two-point discrimination training or a single-point spatially-directed attentional control condition. Training will involve up to 9 additional sessions. Efficacy of training will be assessed by 1) reductions in the spatial extent of pain, 2) reductions in pain intensity and unpleasantness, and 3) reductions in pain-related disability.

Description:

STUDY DESIGN Prior to commencing this investigation, investigators will optimize the tactile discrimination threshold testing (i.e. as per baseline visit, below), and the training conditions, in up to ten participants (patients and/or healthy controls). This will serve as a pilot to refine operational aspects of study procedures before investigators commence the main investigation proposed herein. Following this, youth with either chronic pain (ages 10-17, n=40) or healthy youth (ages 10-17, n=20) will undergo assessments of two-point and single-point discrimination thresholds in an initial session (Aim 1). After this initial session, youth with chronic pain will participate in up to 9 additional sessions of attentional training (Aim 2). These chronic pain patients will be randomized to either two-point discrimination training (n=20) or a single-point spatially-directed attentional control condition (n=20). Participants will not be informed of which intervention they will receive (single-blind study). Psychological questionnaires will be completed in the first and last sessions in order to determine how these variables relate to tactile discrimination and response to training.

STUDY INTERVENTIONS 5.1 Two Point Discrimination Training: Two-point discrimination threshold (TPD) training may be performed 1) at spatial locations remote from pain, 2) at spatial locations adjacent to the region of pain, and/or 3) at spatial locations in the site of pain, if the participant will tolerate it. TPD is defined as the smallest distance between two points at which someone can recognize two points, and not one, touching their skin. As such this is a test of one's ability to identify separate stimulation of two discrete areas, and relies heavily on lateral inhibition. Highly precise mechanical calipers will be gently placed onto the skin and the distance between the prongs will be increased/decreased. After repeated decreases and increases in the distance between the prongs, the TPD will be deemed as the distance at which participants consistently report two points instead of one. One-point stimuli will be interleaved to serve as a control condition. Participants will be informed immediately of correct and incorrect responses as part of the discrimination training.

5.2 Control Stimulation: Participants will undergo a single-point discrimination training at the same sites as described above. Probes of different sizes will be used for this portion - a small diameter probe (~1-5 mm) and a large diameter probe (~6-50mm). The probes will be gently placed in contact with the participants' skin, and the participant will be instructed to respond if they were contacted with the small or large probe. Participants will be informed immediately of correct and incorrect responses as part of the discrimination training.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 60
• Est. completion date: July 16, 2023
• Est. primary completion date: July 17, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 10 Years to 17 Years

Eligibility

Inclusion Criteria:

Chronic Pain Patients:

• Somatically located chronic pain

• amplified musculoskeletal pain syndrome

• complex regional pain syndrome

• low back pain

• fibromyalgia

• other forms of chronic, widespread pain

• Male or female, 10-17 years

• High fluency in written and oral English language

Control Participants:

• Youth in good general health

• Male or female, 10-17 years

• High fluency in written and oral English language

Exclusion Criteria:

• Present significant mental health disorder as defined by DSM V (e.g. psychosis, bipolar disorder, major depression),

• alcohol or drug dependence

• documented developmental delays or impairments (e.g., autism, cerebral palsy, or mental retardation) of a magnitude that would interfere with adherence to study requirements or safe participation in the study

• Primary complaint of migraine or visceral (abdominal) pain, with minimal somatic involvement.

Related Conditions & MeSH terms

• Amplified Musculoskeletal Pain Syndrome (AMPS)
• Chronic Widespread Pain
• Complex Regional Pain Syndrome (CRPS)
• Complex Regional Pain Syndromes
• Ehlers-Danlos Syndrome
• Ehlers-Danlos Syndrome (EDS)
• Fibromyalgia
• Low Back Pain
• Musculoskeletal Pain
• Reflex Sympathetic Dystrophy
• Somatoform Disorders
• Syndrome

Intervention

Behavioral:
• Two-point discrimination training
Patients will undergo multiple sessions of two-point discrimination training.
• One-point discrimination training
Patients will undergo multiple sessions of one-point discrimination training.

Locations

Country	Name	City	State
United States	Cincinnati Children's Hospital Medical Center	Cincinnati	Ohio

Sponsors (1)

Lead Sponsor	Collaborator
Children's Hospital Medical Center, Cincinnati

Country where clinical trial is conducted

United States, 

References & Publications (20)

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Flor H, Nikolajsen L, Staehelin Jensen T. Phantom limb pain: a case of maladaptive CNS plasticity? Nat Rev Neurosci. 2006 Nov;7(11):873-81. Review. — View Citation

Gardner EP, Martin JH, Jessell TM, Kandel ER, Schwartz JH (2000) Principles of neural science. New York: McGraw-Hill.

Groenewald CB, Essner BS, Wright D, Fesinmeyer MD, Palermo TM. The economic costs of chronic pain among a cohort of treatment-seeking adolescents in the United States. J Pain. 2014 Sep;15(9):925-33. doi: 10.1016/j.jpain.2014.06.002. Epub 2014 Jun 19. — View Citation

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Hestbaek L, Leboeuf-Yde C, Kyvik KO, Manniche C. The course of low back pain from adolescence to adulthood: eight-year follow-up of 9600 twins. Spine (Phila Pa 1976). 2006 Feb 15;31(4):468-72. — View Citation

Huguet A, Miró J. The severity of chronic pediatric pain: an epidemiological study. J Pain. 2008 Mar;9(3):226-36. Epub 2007 Dec 21. — View Citation

King S, Chambers CT, Huguet A, MacNevin RC, McGrath PJ, Parker L, MacDonald AJ. The epidemiology of chronic pain in children and adolescents revisited: a systematic review. Pain. 2011 Dec;152(12):2729-38. doi: 10.1016/j.pain.2011.07.016. Review. — View Citation

Lotze M, Moseley GL. Role of distorted body image in pain. Curr Rheumatol Rep. 2007 Dec;9(6):488-96. Review. — View Citation

Maihöfner C, Handwerker HO, Neundörfer B, Birklein F. Cortical reorganization during recovery from complex regional pain syndrome. Neurology. 2004 Aug 24;63(4):693-701. — View Citation

Maihöfner C, Handwerker HO, Neundörfer B, Birklein F. Patterns of cortical reorganization in complex regional pain syndrome. Neurology. 2003 Dec 23;61(12):1707-15. — View Citation

Moseley GL, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain. 2008 Jul 31;137(3):600-8. Epub 2007 Dec 3. — View Citation

O'Sullivan PB, Beales DJ, Smith AJ, Straker LM. Low back pain in 17 year olds has substantial impact and represents an important public health disorder: a cross-sectional study. BMC Public Health. 2012 Feb 5;12:100. doi: 10.1186/1471-2458-12-100. — View Citation

Price DD (1999) Psychological mechanisms of pain and analgesia, 0 Edition. Seattle: IASP Press.

Price DD, Bush FM, Long S, Harkins SW. A comparison of pain measurement characteristics of mechanical visual analogue and simple numerical rating scales. Pain. 1994 Feb;56(2):217-26. — View Citation

Price DD, McHaffie JG, Larson MA. Spatial summation of heat-induced pain: influence of stimulus area and spatial separation of stimuli on perceived pain sensation intensity and unpleasantness. J Neurophysiol. 1989 Dec;62(6):1270-9. — View Citation

Quevedo AS, Coghill RC. Attentional modulation of spatial integration of pain: evidence for dynamic spatial tuning. J Neurosci. 2007 Oct 24;27(43):11635-40. — View Citation

Quevedo AS, Mørch CD, Andersen OK, Coghill RC. Lateral inhibition during nociceptive processing. Pain. 2017 Jun;158(6):1046-1052. doi: 10.1097/j.pain.0000000000000876. — View Citation

Wand BM, Di Pietro F, George P, O'Connell NE. Tactile thresholds are preserved yet complex sensory function is impaired over the lumbar spine of chronic non-specific low back pain patients: a preliminary investigation. Physiotherapy. 2010 Dec;96(4):317-23. doi: 10.1016/j.physio.2010.02.005. — View Citation

* Note: There are 20 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in spatial extent of pain from baseline visit to final visit	total area of body affected by pain	baseline to final visit which is up to 5 weeks from baseline
Primary	Change in pain ratings from baseline visit to final visit	Ratings of current pain intensity on a non-numerical visual analog scale ranging from "not at all intense" to "most intense pain sensation imaginable" and of pain unpleasantness on a non-numerical visual analog scale ranging from "not at all unpleasant" to "most unpleasant pain imaginable".	baseline to final visit which is up to 5 weeks from baseline
Primary	Change in pain-related disability from baseline visit to final visit	pain-related disability as assessed by the Functional Disability Index	baseline to final visit which is up to 5 weeks from baseline
Secondary	Change in two point discrimination threshold from baseline visit to final visit	Calipers moving at fixed distances to determine threshold of two point detection	baseline to final visit which is up to 5 weeks from baseline