The Effect of Vaporized Cannabis on Neuropathic Pain in Spinal Cord Injury

描述（由申请人提供）：本研究旨在评估汽化大麻对脊髓损伤所致神经性疼痛患者的镇痛作用。将对大麻（3.5%和7.0% δ -9- thc）与安慰剂对自发性和诱发性疼痛的影响进行一项受试者内交叉研究。将对疼痛强度和疼痛不愉快程度进行评估，以确定大麻对感觉-辨别性疼痛的影响是否大于或小于动机-情感成分。如果存在，将通过重复测试评估机械异常性疼痛的区域，以确定通过汽化器吸入大麻后异常性疼痛消退的程度（如果有的话）。热诱发性疼痛将通过Medoc TSA 2001定量感官测试仪，使用电子控制的Peltier接触热模将轻度至中度疼痛的热刺激传递到受试者身体的疼痛区域。神经心理功能（注意力、学习记忆和精神运动表现）将在雾化大麻前后通过数字符号模态测试、霍普金斯语言学习测试、凹槽钉板测试、轨迹制作测试和节奏性听觉连续加法测试（PASAT）进行评估。情绪反应将使用情绪状态档案进行评估。然后将抗痛觉程度与大麻的神经心理和情绪影响进行比较，以概述所使用剂量的相对有效性（即功效与副作用）。主要的假设是，汽化大麻可以诱导自发性和诱发性疼痛的神经性疼痛受试者的抗痛觉改变。第二个假设是，使用更高剂量的大麻（7.0%）将诱导相同或更大程度的抗感觉，这并非独立于情绪、认知和精神运动表现的差异。

DESCRIPTION (provided by applicant): The present study will be designed to evaluate the analgesic effects of vaporized cannabis in patients with neuropathic pain due to spinal cord injury. A within-subject crossover study of the effects of cannabis (3.5% and 7.0% delta-9-THC) versus placebo on spontaneous and evoked pain will be performed. Both pain intensity and pain unpleasantness will be assessed to see if marijuana affects sensory-discriminative pain more or less than the motivational-affective component. If present, areas of mechanical allodynia will be assessed with repeated testing to determine the degree of the allodynia regression (if any) after inhaling cannabis via a vaporizer. Heat evoked pain will be studied using mild to moderately painful heat stimuli delivered to the painful area of the subject's body using an electronically controlled Peltier contact thermode via a Medoc TSA 2001 quantitative sensory tester. Neuropsychological functioning (attention, learning and memory, and psychomotor performance) will be evaluated with the Digit Symbol Modalities Test, the Hopkins Verbal Learning Test, the Grooved Pegboard Test Trail Making Test and the Paced Auditory Serial Addition Test (PASAT) before and after the administration of vaporized cannabis. Emotional responses will be evaluated using the Profile of Moods States. The degree of antinociception will then be compared with neuropsychological and mood effects of cannabis for a synopsis of the relative effectiveness (i.e., efficacy versus side-effects) of the doses employed. The major hypothesis will be that vaporized cannabis can induce antinociceptive changes in spontaneous and evoked pain in subjects with neuropathic pain. The second hypothesis will be that the higher dose of cannabis (7.0%) employed will induce the same or a greater degree of antinociception that is not independent of differences in mood, cognition, and psychomotor performance. PUBLIC HEALTH RELEVANCE: This study will demonstrate that vaporized marijuana results in antinociception when compared to placebo in subjects with spinal cord injury. To further evaluate potential benefits and side effects, the effect of different strengths of cannabis on mood, cognition and psychomotor performance will also be measured.