No abstract

The sciatic nerves of rabbits were frozen at different temperatures (-20 degrees C, -60 degrees C, -100 degrees C, -140 degrees C, and -180 degrees C). The morphology and function of the frozen nerves were examined with light microscopy (hematoxylin and eosinophilin stain and a histochemical thiocholine method) and electron microscopy. The function of the nerve after freezing was assessed using short latency somatosensory evoked potentials, sensory conduction velocity, and electromyogram at various intervals after freezing. There were no changes in morphology or function of nerves cryolesioned at -20 degrees C. The nerve fibers cryolesioned at -60 degrees C showed signs of freezing degeneration and lost their conductive function although, these nerves all recovered. Approximately half of nerve fibers cryolesioned at -100 degrees C showed Wallerian degeneration, and although the time to remyelination was delayed, nerve regeneration was still complete. At -140 degrees C and -180 degrees C the nerve fibers showed immediate necrosis, with destruction of basal membranes and proliferation of collagen fibers. The results explained the mechanism of cryoanalgesia. Our study demonstrates that cryo-temperatures lower than -140 degrees C will cause permanent alterations in nerve morphology and function, whereas warmer temperatures do not result in permanent nerve damage and are therefore not likely to provide long-term analgesia to patients.

This article reviews the relationship between the spinal dorsal ramus system and low back pain, including the anatomy, clinical findings, pathogenesis and treatment of low back pain mediated by spinal dorsal ramus and zygapophysial (facet) joint syndrome. Each spinal dorsal ramus arises from the spinal nerve and then divides into a medial and lateral branch. The medial branch supplies the tissues from the midline to the zygapophysial joint line and innervates two to three adjacent zygapophysial joints and their related soft tissues. The lateral branch innervates the tissues lateral to the zygapophysial joint line. The clinical pain presentations follow these anatomic distributions, which can be used for localizing the involved dorsal ramus. The diagnosis can be confirmed by performing a single dorsal ramus block that results in relief of pain and muscle spasm. Etiologically, any factor that stimulates the spinal dorsal ramus can cause low back pain, which is distinct from zygapophysial joint syndrome. Clinically, L1 and L2 are the most common sites of dorsal rami involvement. Treatment includes spinal dorsal ramus injection therapy and percutaneous neurotomy. Summarily, irritation of the spinal dorsal ramus system is a potential source of low back pain. Based on the anatomy and clinical presentation, the involved spinal dorsal ramus can be localized and treated

Proper patient selection is paramount to a successful outcome of arthroscopic disc surgery. Sequestered migrated herniations and large central herniations at L5-S1 in individuals with elevated iliac crests will require open surgery.

The results of this retrospective trial demonstrate that HVPC plus standard care improved the healing rate of high-risk ischemic wounds. A direct relationship was shown between improved healing rates and increased periwound perfusion. A prospective randomized controlled trial is needed to further support these observational, preliminary findings.

C(1/2), C(2/3) facet joint injections and C(2), C(3) spinal rami blocks were effective and well tolerated for the treatment of cervicogenic headache in this study. The procedures provided significant and prolonged pain relief in the majority of patients. Larger controlled studies are needed to further evaluate the efficacy of this treatment modality in cervicogenic headache.

No abstract

Chronic Pain is a serious public health problem both in the United States and globally. Neurolysis therapy with radiofrequency, phenol/alcohol, and cryotherapy has been used in pain management for several decades. Characteristics of each modality are reviewed in this article including: history, mechanism, clinical indication, contraindication, side effects, and efficacy. An extensive literature search has been performed to determine which technique has the best efficacy while producing the least amount of adverse effects.