Trial Outcomes & Findings for Central Nervous System Amplification in Lumbar Failed Back Surgery Syndrome (NCT NCT03444168)

Central Nervous System Amplification in Lumbar Failed Back Surgery Syndrome

Measured by the Brief Pain Inventory (BPI). The BPI scores are a numerical rating scale and range from 0 to 10. A score of 0 is equal to no pain and a score of 10 is equal to pain as bad as you can imagine.

2011 Fibromyalgia Survey score is calculated by combining the widespread pain index (WPI) and the Symptom Severity Scale (SSI) to derive a score from 0-31. Scores greater than or equal to 13 indicate a diagnosis of Fibromyalgia. Higher scores indicate the degree of central sensitization present in a given individual.

PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.

PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.

The Oswestry Disability Index will be used to assess low back pain. There are 10 sections on the index. Each section has a possible score of 5. The total possible range of scores is 0 to 50. A score of 0 indicates no pain. A score of 50 indicates the person is bed-bound or exaggerating their symptoms.

A 6-item catastrophizing scale that measures ways to cope or deal with pain. Each item is scored on a scale of 0-6. Scores can range from 0-36, with the higher the score the higher the rate of catastrophizing.

Pressure pain sensitivity is measured by Algometry (measured at the trapezius and lumbar spine). It yields a pressure pain threshold value measured in kPA. Tests were performed at the Left and Right trapezius in triplicate at each site and the average is calculated and used for analysis.

Pressure pain sensitivity is measured by Algometry (measured at the trapezius and lumbar spine). It yields a pressure pain threshold value measured in kPA.Tests were performed at the Left and Right lumbar spine in triplicate at each site and the average is calculated and used for analysis.

Pressure pain sensitivity is measured by the Multimodal Automated Sensory Testing (MAST) System (measured at the thumbnail). It yields a pressure pain threshold value measured in kg/cm2. Thumb Pain30, Pain40, and Pain50 are the pressure intensities that provoke a pain rating of 30/100, 40/100, and 50/100, respectively. Thumb Pain Tolerance is the pressure intensity that provokes a response greater than or equal to 80/100.

Conditioned Pain Modulation as measured at the thumbnail using the MAST. It yields a numerical pain rating difference on a 0-100 numerical scale that can either be positive or negative called CPM magnitude. CPM magnitude will be calculated as the difference (post-pre) in the mean of the three pain ratings given to the test stimulus prior to the conditioning stimuli and the three pain ratings of the test stimulus given during the conditioning stimuli. A reduction in test stimulus rating by conditioning stimulation implies functional (inhibitory) CPM, and the degree of reduction expresses the efficiency of CPM.