Key Benefits of Nerve Root Blockade
Recent study have demonstrated increased nerve root blood flow in an animal model, by applying local anesthetic to the nerve root Pain relief with nerve blockade may be explained by the increased blood flow and resolution of ischemia present to root compression. Spinal Blocks are diagnostic procedures that help to determine the source of patients' back pain. They may also temporarily relieve pain. There are two main types of blocks - facet blocks and selective nerve root blocks.
Link to article : Paraspinal Injections: Facet Joint and Nerve Root Blocks
Nerve Root Blockade
Clinically, radiculopathic (pain secondary to nerve root inflammation) pain can be relieved by the direct application of local anesthetic and/or steroid preparation to the nerve root. The mechanism(s) for the prolonged analgesia from these blocks are only starting to be understood. A recent animal study has demonstrated that a vascular connections exists between the epidural space and the nerve root. This vascular connection can help to explain the transfer of inflammatory nucleus pulposus materials from, the epidural space, selectively, to the nerve root. The therapeutic, effectiveness of nerve root injection with local anesthetic and/or steroid may be explained by the transfer of these drugs via this vascular connection to the epidural space.
Alternate explanations can be offered for the response to nerve root injection. Compression or manipulation of nerve root, during retraction in surgery, or tethering in disc herniation, can cause nerve root ischemia and subsequent injury.
The recent study of nerve root compression, have demonstrated increased nerve root blood flow in an animal model, by applying local anesthetic either to the nerve root itself or to the adjacent sympathetic ganglion.Thus the therapeutic effect of somatic or sympathetic block may be related to increased radicals, blood flow, improved nutrition, or, potentially, to the "washout" of inflammatory or irritative substances.
Other animal studies have suggested that nociceptive fibers supplying the lumbar paravertebral muscles may be responsive to sympathetic neural input. These findings suggest a role, although undefined, for the sympathetic nervous system in low back and radicular pain. The blood flow, to the nerve root itself is predominantly from the periphery. Pain relief with sciatic or sympathetic blockade distal to the root lesion may therefore be explained, partially, by the increased blood flow and resolution of ischemia present to root compression.
In addition to the alterations in blood flow, other mechanisms may account for the pain following nerve root compression. Experimental chronic nerve root compression can produce specific changes in neuropeptide levels within the peripheral nerve and dorsal horn. The clinical and therapeutic significance of these findings is just starting to be appreciated.
From: Cousins MJ, Bridenbaugh PO: “NEURAL BLOCKADE in Clinical Anesthesia and Management of Pain” Lippincott - Raven 1998 p.905
- Facet Joint Block (Medial Nerve Block)
- Selective Nerve Root Block
- Sacroiliac Joint Block
- Epidural Injection
Link to article : Paraspinal Injections: Facet Joint and Nerve Root Blocks
Nerve Root Blockade
Clinically, radiculopathic (pain secondary to nerve root inflammation) pain can be relieved by the direct application of local anesthetic and/or steroid preparation to the nerve root. The mechanism(s) for the prolonged analgesia from these blocks are only starting to be understood. A recent animal study has demonstrated that a vascular connections exists between the epidural space and the nerve root. This vascular connection can help to explain the transfer of inflammatory nucleus pulposus materials from, the epidural space, selectively, to the nerve root. The therapeutic, effectiveness of nerve root injection with local anesthetic and/or steroid may be explained by the transfer of these drugs via this vascular connection to the epidural space.
Alternate explanations can be offered for the response to nerve root injection. Compression or manipulation of nerve root, during retraction in surgery, or tethering in disc herniation, can cause nerve root ischemia and subsequent injury.
The recent study of nerve root compression, have demonstrated increased nerve root blood flow in an animal model, by applying local anesthetic either to the nerve root itself or to the adjacent sympathetic ganglion.Thus the therapeutic effect of somatic or sympathetic block may be related to increased radicals, blood flow, improved nutrition, or, potentially, to the "washout" of inflammatory or irritative substances.
Other animal studies have suggested that nociceptive fibers supplying the lumbar paravertebral muscles may be responsive to sympathetic neural input. These findings suggest a role, although undefined, for the sympathetic nervous system in low back and radicular pain. The blood flow, to the nerve root itself is predominantly from the periphery. Pain relief with sciatic or sympathetic blockade distal to the root lesion may therefore be explained, partially, by the increased blood flow and resolution of ischemia present to root compression.
In addition to the alterations in blood flow, other mechanisms may account for the pain following nerve root compression. Experimental chronic nerve root compression can produce specific changes in neuropeptide levels within the peripheral nerve and dorsal horn. The clinical and therapeutic significance of these findings is just starting to be appreciated.
From: Cousins MJ, Bridenbaugh PO: “NEURAL BLOCKADE in Clinical Anesthesia and Management of Pain” Lippincott - Raven 1998 p.905
