Efficacy of post-operative analgesia after posterior lumbar instrumented fusion for degenerative disc disease: a prospective randomized comparison of epidural catheter and intravenous administration of analgesics.

This prospective study aimed to compare the efficacy of epidural (EDA) versus intravenous (PCA) application of analgesics after lumbar fusion. Fifty-two patients scheduled for elective posterior instrumented lumbar fusion were randomized into two groups. EDA patients received an epidural catheter intraoperatively, and administration of ropivacain and sulfentanil was started after a normal postoperative wake-up test in the recovery room area. PCA patients received intravenous opioids in the post-operative period. Differences between EDA and PCA groups in terms of patient satisfaction with respect to pain relief were not significant. Nevertheless, EDA patients reported less pain on the third day after surgery. There were significantly more side effects in the EDA group, including complete reversible loss of sensory function and motor weakness. There were no major side effects, such as infection or persisting neurological deficits, in either group. The routine use of epidural anesthesia for lumbar spine surgery has too many risks and offers very little advantage over PCA.

Memantine treatment of complex regional pain syndrome: a preliminary report of six cases.

OBJECTIVES: Recent studies have confirmed the contribution of the central nervous system (CNS) to the pathogenesis of Complex Regional Pain Syndrome (CRPS), because animal models of neuropathic pain syndromes demonstrate an overexpression of N-methyl-D-aspartate-receptors in the CNS. The aim of this work was to study the influence of a central acting drug-the N-methyl-D-aspartate receptor antagonist Memantine-in patients with CRPS of one upper extremity. Here we present the results of 6 patients treated with Memantine for 8 weeks. METHODS: All patients developed CRPS after traumatic injury to one upper extremity. To document changes during the study, levels of pain were measured after clenching the hand using a numeric pain intensity scale ranging from 0 (no pain) to 10 (maximum pain). Motor symptoms were documented for the fingers (fingertips to palm and fingernails to table) and the wrist (flexion/extension). Furthermore, the force was analyzed using a JAMAR-Dynamometer and a Pinchmeter. For assessment of central changes, functional magnetic resonance imaging and magnetoencephalography were used to further document the results of other experiments in 1 patient. Autonomic changes were photographed and pictures were compared before and after treatment with Memantine. RESULTS: Six months after treatment with Memantine, all patients showed a significant decrease in their levels of pain which coincided with an improvement in motor symptoms and autonomic changes. The functional magnetic resonance imaging and magnetoencephalography results provided evidence of cortical reorganization [changes in somatotopic maps in the primary somatosensory cortex (S1)]. These changes returned to a cortical pattern comparable to the unaffected side after treatment with Memantine. DISCUSSION: Based on these first results, the use of Memantine for treatment of CRPS seems promising and supports the hypothesis of a CNS contribution to the pathogenesis and maintenance of neuropathic pain syndromes.