(539) SP6 manual acupuncture reduces mechanical hyperalgesia in neurophatic pain

Abstract

While patients with carpal tunnel syndrome (CTS) report pain and paresthesia in conjunction with decreased median nerve conduction velocities, patients with idiopathic hand pain (IHP) report similar symptoms but with normal nerve conduction. While brain plasticity has been reported for CTS, the effects of acupuncture on structural plasticity in either IHP or CTS are unknown. We evaluated 19 IHP patients, 21 CTS patients, and 13 healthy controls (HC) with structural T1weighted MRI at 3T (Siemens Trio) before and after 8weeks of acupuncture. Symptoms were evaluated with the Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ) before, after, and 3-months following acupuncture therapy. Acupuncture included 2Hz electrical stimulation at acupoints PC7 and TW5 near the affected wrist. Gray matter thickness data were contrast between IHP and CTS at baseline, and before versus after acupuncture. Difference maps were calculated, cluster corrected for multiple comparisons at p=0.05. Cortical thickness data were also correlated with BCTSQ change. BCTSQ symptoms decreased following acupuncture, retained at 3-month follow-up in both groups (IP; baseline: 2.760.6, mean6SD, post-acup: 1.960.5, 3-months: 1.760.5, CTS; baseline: 2.860.6, post-acup: 2.160.7, 3-months: 2.260.7, p<0.01). At baseline, cortical thickness in bilateral insulae was significantly greater in IHP compared to CTS (p<0.05), and both groups showed, on average, reduced thickness compared to HC. Following acupuncture in IHP, cortical thickness was significantly increased in bilateral insulae. Furthermore, insula thickness increase was negatively correlated with post-acupuncture symptom change (r=-0.53, p=0.05). Thus, greater thickness increase was associated with greater reduction in symptom severity. These changes were not seen for CTS. Symptoms were reduced by acupuncture and sustained during 3-months follow up. Increased insula thickness postacupuncture was correlated with symptom reduction for IHP. Thus, cortical thickness may be sensitive to improvements in symptomatology, but not when such symptoms are maintained by a peripheral lesion. Funded by NCCAM, NIH.NADA acupuncture protocol is the most common form of acupuncture treatment for substance addiction in the US and Europe. This protocol has been utilized as an adjunctive therapy for addiction treatment, behavioral health, cancer and blood disorders. The protocol uses five ear points: shenmen, sympathetic, kidney, liver, and lung. Clinical studies had shown contradicting results regarding the efficacy of NADA protocol in controlling opioid-induced withdrawal and other craving-related symptoms. The mechanism by which it serves as a successful treatment remains inconclusive, therefore establishing an animal model of NADA acupuncture treatment is important. Repeated morphine administration in rodents has been shown to produce locomotor sensitization. In addition, discontinuation of morphine treatment results in withdrawal symptoms, including increased pain sensitivity. We administered rats with 10 mg/kg of mo...