Cognitive Changes With Gabapentin Treatment

Study Overview
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Brief Summary
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This is a single-cohort, prospective, observational study evaluating the effects of gabapentin on cognition. The goal of the study is to determine whether there is a measurable change in cognitive function from baseline in patients who are prescribed gabapentin for the treatment of neuropathic pain.

Official Title
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Cognitive Changes Associated With Initiation of Gabapentin Treatment in Adults With Chronic Pain

Conditions
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Neuralgia Peripheral, Pain

Intervention / Treatment
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* Drug: Gabapentin
* Diagnostic Test: BTACT
* Diagnostic Test: BPI
* Diagnostic Test: HADS
* Diagnostic Test: SLP9
* Diagnostic Test: NPSI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18 and 85 Diagnosis of neuropathic pain Patient report of average daily pain intensity in the last week >3 on 0-10 Numerical Rating Scale (NRS). Able and willing to sign an IRB-approved written informed consent Exclusion Criteria: Current pregabalin treatment Patient has started taking a new pain medication, or has changed their pain medication dose, in the past 4 weeks. Treatment with opioids exceeding 60mg MME. Severe cognitive impairment that is documented in medical chart.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with Neuropathic Pain<br> | Drug: Gabapentin<br>* Titration of gabapentin will be standardized as 300mg QHS and increased by 300mg every 3 days until taking 1200mg TID or maximum tolerable dose. Subjects will undergo cognitive evaluation prior to initiation of the medication, at 1 week (when titrated to approximately 900mg/day), 3 weeks (when titrated to approximately 2100mg/day), and at 6 weeks (when titrated to 3600mg/day or maximum tolerable dose).<br>Diagnostic Test: BTACT<br>* Cognition measure: Brief Test of Adult Cognition by Telephone<br>Diagnostic Test: BPI<br>* Pain severity and interference at baseline using the Brief Pain Inventory<br>Diagnostic Test: HADS<br>* Assessment of depression and anxiety with the Hospital Anxiety and Depression Scale<br>Diagnostic Test: SLP9<br>* Assessment of Sleep<br>Diagnostic Test: NPSI<br>* Assessment of neuropathic components<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the Brief Test of Adult Cognition by Telephone (BTACT) | Measure of cognitive functioning that assesses multiple dimensions central for effective functioning across adulthood: episodic memory, working memory, reasoning, verbal fluency, and executive functioning. Scoring: Word List Recall - Immediate & Delayed Total number unique is total number of correct responses (range 0-15) Backward Digit Span Score is highest number of digits reached (range 0, 2-8) Category Fluency Total number unique is total number of correct responses Red/Green Accuracy Normal baseline score is total number correct in normal baseline condition (range 0-20) Number Series Total number of items correct (range 0-5) Backward Counting Last number reached Total number of errors Total number of digits produced is calculated as: 100 - (number reached + number errors) | up to 6 weeks after treatment initiation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pain severity - BPI | Medical questionnaire used to measure pain, developed by the Pain Research Group of the WHO Collaborating Center for Symptom Evaluation in Cancer Care 0-10 pain severity scale, 0=no pain, 10=pain as bad as you can imagine (scoring-a mean severity score) 0-10 pain relief scale, 0%=no relief, 100%=complete relief (only one question) 0-10 pain interference scale, 0=does not interfere, 10=completely interferes (scoring-mean of 7 items) | up to 6 weeks after treatment initiation | 
| Change in Depression and Anxiety - HADS | Measure of anxiety and depression in a general population of patients. Popular for clinical practice and research. Score- 8-10 mild, 11-14 moderate, 15-21 severe (separate scores for anxiety and depression) | up to 6 weeks after treatment initiation | 
| Change in Sleep Problems - SLP9 | Questionnaire to evaluate problems with sleep. Scale: 1=all of the time, 2=most of the time, 3=a good bit of the time, 4=some of the time, 5=a little of the time, 6=none of the time Final scores range from 0-100, with higher scores indicating more sleep problems. To score the SPI II, you must first transform the responses of each item into a new score. For item 1, responses of 1, 2, 3, 4, and 5 are scored as 0, 25, 50, 75, and 100, respectively. For items 3 and 9, ratings of 1 through 6 are scored as 0, 20, 40, 60, 80, and 100, respectively. All of the other items are reverse-scored (lower ratings indicate more sleep difficulties) and so ratings of 1 through 6 for these items are scored as 100, 80, 60, 40, 20, and 0, respectively. The final SPI II score is an average of the item scores responded to. | up to 6 weeks after treatment initiation | 
| Change in Neuropathic Pain - NPSI | Questionnaire to evaluate the different symptoms of neuropathic pain. 0-10 scale, 0=no sensation, 10=greatest sensation intensity | up to 6 weeks after treatment initiation |