Cryoablation for the treatment of occipital neuralgia.

BACKGROUND: Treatment of occipital neuralgia (ON) can be complex, though many treatment options exist. Cryoablation (CA) is an interventional modality that has been used successfully in chronic neuropathic conditions and is one such option. OBJECTIVE: To study and evaluate the efficacy and safety of cryoablation for treatment of ON. STUDY DESIGN: Retrospective evaluation. SETTING: Academic university-based pain management center. METHODS: All patients received local anesthetic injections for ON. Patients with greater than or equal to 50% relief and less than 2 week duration of relief were treated with CA. RESULTS: Thirty-eight patients with an average age of 49.6 years were included. Of the 38 patients, 20 were treated for unilateral greater ON, 10 for unilateral greater and lesser ON, and 8 for bilateral greater ON. There were 10 men and 28 women, with an average age of 45.2 years and 51.1 years, respectively. The average relief for all local anesthetic injections was 71.2%, 58.3% for patients who reported 50 - 74% relief (Group 1) and 82.75% for patients who reported greater than 75% relief (Group 2). The average improvement of pain relief with CA was 57.9% with an average duration of 6.1 months overall. Group 1 reported an average of 45.2% relief for an average of 4.1 months with CA. In comparison, Group 2 reported an average of 70.5% relief for 8.1 months. The percentage of relief (P = 0.007) and duration of relief (P = 0.0006) was significantly improved in those reporting at least 75% relief of pain with local anesthetic injections (Group 2 vs Group 1). Though no significance in improvement from CA was found in men, significance was seen in women with at least 75% benefit with local anesthetic injections in terms of duration (P = 0.03) and percentage (P = 0.001) of pain relief with CA. The average pain score prior to CA was 8 (0 - 10 visual analog scale, VAS), this improved to 4.2, improvement of 3.8 following CA at 6 months (P = 0.03). Of the 38 patients, 3 (7.8%) adverse effects were seen. Two patients reported post procedure neuritis and one was monitored for procedure-related hematoma. LIMITATIONS: Study limitations include the retrospective nature of the study. Additionally, only the percentage of relief, pain score, and duration of relief were collected. CONCLUSIONS: CA is safe, and should be considered in patients with ON. KEY WORDS: Cryoablation, cryoanalgesia, occipital neuralgia, treatment, adverse effects.

Androgen deficiency in long-term intrathecal opioid administration.

BACKGROUND: Intrathecal drug delivery of opioids is an efficient and effective treatment option for pain management in the chronic nonmalignant pain population. As with all treatments, in addition to the benefits, risks and side effects exist. One such risk in intrathecal opioids is opioid-induced androgen deficiency. OBJECTIVE: This study evaluates opioid-induced androgen deficiency in long-term intrathecal opioid administration in chronic nonmalignant pain. STUDY DESIGN: Case series. Sixteen consecutive patients with intrathecal drug delivery with opioids were screened for androgen deficiency. SETTING: Academic university-based pain management center. METHOD: All the subjects were seen in a 2 month period, during a scheduled maintenance refill visit. Eight consecutive men and eight consecutive women receiving intrathecal drug delivery therapy for non-malignant chronic pain were ordered blood work and asked to complete a questionnaire. Patient and patient-related data were also collected. RESULTS: Ten of the 16 (62.5%) patients were found to have androgen deficiency, 4 of 8 men based on free testosterone levels and 6 of 8 women based on DHEA levels. In men, erectile dysfunction correlated with endocrine dysfunction (P = 0.02) while depressive symptoms correlated in women (P = .03). Overall, 2 of the 16 patients had hydromorphone as the opioid in the intrathecal system. Both patients had normal endocrine functions. Both patients with hydromorphone were men and the use of hydromorphone showed an insignificant trend (P = 0.06). Three of the 4 men with normal endocrine functions had in addition to an opioid, bupivacaine, in the intrathecal system. The presence of bupivicaine in men was significant (P = 0.02). No women had bupivicaine while one of the 8 women had clonidine in addition to the opioid. Presence of another substance in addition to the opioid showed an insignificant trend (P = 0.08). LIMITATIONS: Study limitations include the small sample size and case series nature. Additionally the symptoms data was solely based on subjective patient reports. CONCLUSIONS: Androgen deficiency is common in patients treated with intrathecal opioids for chronic nonmalignant pain. Patients experience numerous and wide ranging symptoms. Erectile dysfunction may be more suggestive for androgen deficiency in men while complaints of depressed mood may be correlative in women. Additionally, combining bupivicaine with the intrathecal opioid may provide a protective role.