The primary objective of the proposed pilot study is to determine the efficacy of pregabalin in prolonging the time to onset of pain and reducing the severity of pain associated with walking in patients with neurogenic claudication. Neurogenic claudication is defined as movement induced leg pain, numbness, heaviness, or vague discomfort in part or all of one or both legs provoked with walking and standing and relieved by sitting, squatting, or forward flexion posturing. The secondary objective is to examine the functional benefit of pregabalin with respect to improvement in duration and distance of walking.
Subjects were randomized into one of two treatment sequences: pregabalin/active placebo or active placebo/pregabalin. Each arm lasted 10 days, with a washout period of 10 days between treatments. Pregabalin was administered as a standardized two step titration, starting at 75mg twice daily up to a maximum daily dose of 150mg twice daily; and likewise, diphenhydramine (active placebo) was administered starting at 6.25mg twice daily up to a maximum daily dose of 12.5mg twice daily. The primary endpoint was time to first symptoms of moderate intensity (NRS ≥ 4/10) during treadmill ambulation. Ambulation assessment was performed during the screening visit, and on day 10 of each period to evaluate pain intensity associated with walking as well as distance covered by the patients. Quantitative assessment of ambulation was conducted on a treadmill at 0° ramp incline at 1.2 miles per hour (mph). Measurement of self-reported symptom severity using the NRS at baseline, and every 30 seconds for a maximum of 15 minutes was recorded. The following information was also recorded: time to first symptoms, total ambulation time. The examination was stopped after 15 minutes or at the onset of severe symptoms. Severe symptoms were defined as the level of discomfort that would make patients stop walking in usual life situations. No one was encouraged or prompted to continue walking beyond this point. Patients were instructed to walk with an upright posture. They were not permitted to lean forward or hold onto the handrails during the examination. Secondary outcome measures included area under the curve of present pain intensity with ambulation at each specified time point, final pain intensity with walking, walking tolerance, time to return to baseline pain level after ambulation, as well as the results of a series of pain related questionnaires including: Visual Analog Scale (VAS), Patient Global Assessment (PGA), NRS, Roland Morris Disability Questionnaire (RMDQ), modified Brief Pain Inventory short form (mBPI-sf), Oswestry Disability Index (ODI), and Swiss Spinal Stenosis (SSS).
Study Type
Pregabalin started at 75mg twice daily for 3 days; pregabalin increased to 150mg twice daily for 7 days; pregabalin reduced to 75mg twice daily for 3 days.
diphenhydramine started at 6.25mg twice daily for 3 days; diphenhydramine increased to 12.5mg twice daily for 7 days; diphenhydramine reduced to 6.25mg twice daily for 3 days.
2180 South Clinton Avenue
Rochester, New York, United States
Time to First Symptoms of Moderate Pain
Using the Numeric Rating Scale (NRS) (0=no pain, 10=worst pain imaginable)the time to first symptoms (Tfirst) with a NRS score greater than or equal to 4 (moderate pain level), with treadmill ambulation was measured.
Time frame: 10 days
Final Pain as Measured by NRS
Subjects were instructed to walk on the treadmill and to tell the research coordinator to stop testing when they reached the point at which they typically would need to stop and sit down, or until 15 minutes had elapsed. At defined intervals subjects were asked what their pain level was according to the NRS. When the subject reached their maximum distance, they were asked their NRS score. This was recorded as final pain intensity. Using the Numeric Rating Scale (NRS) (0=no pain, 10=worst pain imaginable)the time to first symptoms (Tfirst) with a NRS score greater than or equal to 4 (moderate pain level), with treadmill ambulation was measured.
Time frame: 10 days
Total Distance
Subjects were instructed to walk on the treadmill and to tell the research coordinator to stop testing when they reached the point at which they typically would need to stop and sit down, or until 15 minutes had elapsed. When the subject reached their maximum distance, the treadmill testing was stopped. This was recorded as total distance based on number of minutes and seconds walked. Minutes was converted to meters based on calculation of defined speed of the treadmill.
Time frame: 10 days
Recovery Time
After the subject completed the treadmill test they were asked to immediately return to the seated position. At this point a timer was started. When the subjects pain level returned to baseline (level of pain subject felt in a seated position before walking) the time was stopped. This was recorded as recovery time. Maximum recovery time is 15 minutes.
Time frame: 10 days
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
29
Area Under the Curve
Subjects were instructed to walk on the treadmill and to tell the research coordinator to stop testing when they reached the point at which they typically would need to stop and sit down, or until 15 minutes had elapsed. At defined intervals (every 30 seconds) subjects were asked what their pain level was according to the NRS. The area under the curve of present pain intensity multiplied by the amount of time the subject walked.
Time frame: 10 days
Visual Analog Scale (VAS)
The VAS asked subjects to place a mark indicative of their low back pain during the past day on a 100mm line, with 0mm representing no pain and 100mm representing extreme pain.
Time frame: 10 days
Oswestry Disability Index (ODI) Score
The ODI is a set of 10 questions each with five choices (maximum score of 5 points per question) designed to determine how back pain has affected the ability to manage everyday life (pain intensity, personal care, lifting, walking, sitting, standing, sleeping, social life, traveling, and change positions). A total score range of 0-50; score of 0 indicates no disability and a score of 50 would indicate 100% disability.
Time frame: 10 days
Swiss Spinal Stenosis (SSS) Score- Symptom Severity
The SSS is a series of questions asking about symptom severity, physical function, and satisfaction. The symptom severity section is a set of 7 questions (maximum score is 5 points per question) and asks to rate pain for each question based on no pain, mild, moderate, severe or very severe pain. The total score (maximum=35) is added up and divided by seven. The maximum score for the symptom severity section (score=5) indicates very severe symptom severity.
Time frame: 10 days
Swiss Spinal Stenosis- Physical Function
The SSS is a series of questions asking about symptom severity, physical function, and satisfaction. The physical function section is a series of 5 questions (maximum 4 points per question) and asks to rate function for each question based on comfortably, sometimes with pain, always with pain, no functional ability. The total score (max=20) is divided by five. The maximum score for the physical function section (max=4) indicates no ability to function.
Time frame: 10 days
Modified Brief Pain Inventory (mBPI)- Interference Score
The mBPI is a series of questions that rates the severity and impact of pain on daily function. The questionnaire is made up of 4 pain severity items using the NRS scale, and seven pain interference sub-scales. The final interference score is an average of the seven sub-scales (0 indicating no interference and 10 indicating complete interference).
Time frame: 10 days
Roland Morris Disability Questionnaire
The RMDQ consists of 24 yes/no statements about activity limitations due to back pain. These questions center on movement, ambulation, and self-care activities. Positive (yes) answers each contribute 1 point to cumulative score with total scores ranging from 0 (no disability) to 24 (severely disabled).
Time frame: 10 days
Patient Global Assessment (PGA)
Subjects were asked to rate their low back pain according to the PGA. PGA is the impact of disease activity. PGA was measured on a 5-point scale, where 1=very good, 2=good, 3=fair, 4=poor, and 5=very poor.
Time frame: 10 days