A Prospective Study On Efficacy Of Hyperbaric Oxygenation Treatment For Patients With Trigeminal Neuralgia: A Randomized, Double-Blind, Mock Hyperbaric Chamber -Controlled Trial

BackgroundTrigeminal neuralgia (TN) is a recurrent severe shooting neuropathic pain. Treatment of this pain continues to be a challenge in clinical pain management. Hyperbaric oxygen (HBO) therapy has been used successfully in the management of various diseases, which can improve blood partial pressure of oxygen, reduce edema, relieve neural oppression and attenuate inflammatory response. The hypothesis of this protocol is that HBO treatment could relieve neuropathic pain and improve the quality of life in TN patients.ObjectiveA randomized, double-blinded, imitation environment chamber controlled clinical trial was designed to assess the effectiveness and safety of HBO therapy in the primary trigeminal neuralgia patients. MethodsThe patients with primary trigeminal neuralgia enrolled at Pain Clinic of Xijing Hospital were randomly assigned to receive either HBO therapy or imitation environment chamber therapy as control for 10 days treatment. Efficacy was evaluated at Day 10 and Mo 1, Mo 2, Mo 3, and Mo 6 before and after the end of the treatments. The results of efficacy were divided into a short-term outcome for ten days HBO treatment and long-term outcome of six months follow up periods. The primary end point was carbamazepine dosage changed. The secondary end points were visual analogue scal, short-form McGill questionnaire and the patient global impression. Statistical analysis was performed based on the intent-to-treat population. Results42 patients were enrolled at Pain Clinic of Xijing hospital. 35 patients completed the treatment course and six months follow up periods (18 in control group and 17 in HBO group). The number of patients whose VAS score decreased more than 2 cm was 15 (20) after the HBO treatment and 8 (21) after the control treatment. At the Mo 6 after ending treatment, the VAS score decreased more than 2 cm in 11(17) patients of the HBO group, compared with 5(18) of control group. There were significant difference between two groups (p=0.028 and 0.044). The carbamazepine dosage in HBO group is significantly less than the control group, particularly in 1 and 2 month follow up time point, with significant P=0.0167and 0.0472 respectively. Particularly, in the Mo 1 follow-up phases, the percentage of mean decreased CBZ dose of patients in HBO group was more than which was in control group, there were apparent difference (p=0.0494). At the ending HBO treatment (Day 10), 8/20 (40.0%) patients in the HBO group and 2/21 (9.52%) patients in the control group rated themselves'much improved'on the PGIC (P=0.032). At the ending of followup (Month 6), 10/17 (58.8%) patients in the HBO group and 3/18 (16.7%) in the control group rated themselves'much improved'on the PGIC (P=0.035). ConclusionThe present small sample trial demonstrated that HBO therapy can improve the life quality of primary TN patients, and suggeted that HBO therapy is a potential effective therapeutics for patients with neuropathic pain. Therefore, a large sample, multiple center study is needed to confirm the efficacy of HBO therapy on primary TN.