The National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, is looking for individuals to participate in clinical studies. Participating in clinical trials allows you to play an active role in research on the nature and causes of many disorders of the brain and nervous system, and to possibly help physician-scientists develop future treatments. The information below is designed to help you quickly learn about actively recruiting research studies for which you or someone you know may be eligible.


This trial has several objectives: Primary Objective To determine which combination (dose-ratio) of dextromethorphan and lidocaine provides the best balance of pain reduction and toxicity. Secondary Objectives include To evaluate the analgesic efficacy of both dextromethorphan and lidocaine in attenuating pain related to central nervous system sensitization, specifically spontaneous pain, mechanical allodynia, and hyperalgesia.

Eligibility Criteria:

Inclusion Criteria: 1. Healthy male or female adults, age 18 to 70 with central neuropathic pain for a minimum of 3 months following SCI as confirmed by neurologic evaluation, with an average pain intensity score of at least moderate over at least 50% of the day for the 7 days prior to the screening visit and over the 7 days prior to starting study medication. 2. Subjects used no medication or a stabilized medication regimen for chronic and well-controlled medical conditions 3. Serum laboratory examination obtained at study entry: 4. Normal cognitive function. 5. Signed informed consent. Exclusion Criteria: 1. Pregnancy or breast-feeding. 2. Renal or hepatic dysfunction. 3. Significant cardiac disease (e.g. MI within 1 year). 4. Signs or symptoms of central neurological disorder, excluding SCI. 5. Severe psychological disorder requiring treatment. 6. History of hypersensitivity or intolerance to dextromethorphan or lidocaine. 7. Participation in a study of an investigational drug or device within 30 days prior to screening for this study.

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