RESUMO
STUDY DESIGN: Immunohistochemistry labeled pre- and postsynaptic structural markers to quantify excitatory and inhibitory synapses in the spinal superficial dorsal horn at 14 days after painful facet joint injury in the rat. OBJECTIVE: The objective of this study was to investigate the relationship between pain and synapse density in the spinal cord after facet injury. SUMMARY OF BACKGROUND DATA: Neck pain is a major contributor to disability and often becomes chronic. The cervical facet joints are susceptible to loading-induced painful injury, initiating spinal central sensitization responses. Although excitatory synapse plasticity has been reported in the superficial dorsal horn early after painful facet injury, whether excitatory and/or inhibitory synapse density is altered at a time when pain is maintained is unknown. METHODS: Rats underwent either a painful C6/C7 facet joint distraction or sham surgery. Mechanical hyperalgesia was measured and immunohistochemistry techniques for synapse quantification were used to quantify excitatory and inhibitory synapse densities in the superficial dorsal horn at day 14. Logarithmic correlation analyses evaluated whether the severity of facet injury correlated with either behavioral or synaptic outcomes. RESULTS: Facet joint injury induces pain that is sustained until day 14 (Pâ<0.001) and both significantly greater excitatory synapse density (Pâ=â0.042) and lower inhibitory synapse density (Pâ=â0.0029) in the superficial dorsal horn at day 14. Injury severity is significantly correlated with pain at days 1 (Pâ=â0.0011) and 14 (Pâ=â0.0002), but only with inhibitory, not excitatory, synapse density (Pâ=â0.0025) at day 14. CONCLUSION: This study demonstrates a role for structural plasticity in both excitatory and inhibitory synapses in the maintenance of facet-mediated joint pain, and that altered inhibitory, but not excitatory, synapse density correlates to the severity of painful joint injury. Understanding the functional consequences of this spinal structural plasticity is critical to elucidate mechanisms of chronic joint pain. LEVEL OF EVIDENCE: N /A.
Assuntos
Artralgia/fisiopatologia , Vértebras Cervicais/inervação , Corno Dorsal da Medula Espinal/fisiopatologia , Potenciais Sinápticos/fisiologia , Articulação Zigapofisária/inervação , Animais , Artralgia/diagnóstico , Artralgia/etiologia , Vértebras Cervicais/lesões , Hiperalgesia/fisiopatologia , Masculino , Cervicalgia/fisiopatologia , Plasticidade Neuronal/fisiologia , Medição da Dor , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Articulação Zigapofisária/lesõesRESUMO
BACKGROUND: Pain of spinal origin contributes significantly to cervical, thoracic, and lower back pain presentations. Such pain originates in the nerve fibers supplying the joints or the surrounding ligaments and intervertebral discs. Although there has been little detailed discussion of spinal bony innervation patterns in the literature, the clinical implications of these patterns are anatomically and medically significant. METHODS: The present review provides a detailed analysis of the innervation of the spine, identifying the unique features of each part via online search engines. CONCLUSIONS: The clinical implications of these various studies lie in the importance of the innervation patterns for the mechanism of spinal pain. Immunohistochemical studies have provided further evidence regarding the nature of the innervation of the spine.
Assuntos
Dor nas Costas/fisiopatologia , Disco Intervertebral/inervação , Ligamentos/inervação , Cervicalgia/fisiopatologia , Plexo Cervical/fisiopatologia , Humanos , Imuno-Histoquímica , Plexo Lombossacral/fisiopatologia , Articulação Sacroilíaca/inervação , Nervos Espinhais/fisiopatologia , Coluna Vertebral/inervação , Articulação Zigapofisária/inervaçãoRESUMO
AIM: Many techniques are used in the back pain treatment, standing out the facet denervation as a therapeutic option for pain that originates in the facet joints. It's known that the facet joint is an abundant area of nocireceptor innervation, although the distribution and the location of the involved branches have not being well demonstrated. A good comprehension about the affected innervation is very important to get an effective treatment. Purpose of study was to describe innervation of the lumbar facet joints, potentially used in the diagnosis and treatment of painful pictures of the lumbar region by facet syndrome. STUDY DESIGN: anatomical study of nerve roots distribution of the facet joint 3 human corpses. The determination of the neurotomy s point was carried out by direct visualization and the radiological study in human parts. METHODS: Three anatomical pieces of the human lumbar spine were dissected. In those 3 pieces, the facet joint innervation distribution was studied thoroughly using surgical microscope and microsurgical technique. In one of the pieces the needles positioning was first made to test through the radiological study the possible application of the precise denervation in low back pain treatment. RESULTS: The L1 to L4 segments, each dorsal branch of root emits a medial branch that emerges from intertransversal ligament. This branch crosses the superior margin of the medial termination of transverse process, passing through the root of the superior articulate process. Each branch innerves the anterior region of the inferior facet and the inferior portion of articulation which one spins around. The L5 dorsal branch was larger than the superior branches. It emerges dorsally and in the inferior region on top of the sacrum wing. This nerve is in the bone fissure of the junction between the wing and the posterior region of the sacrum articular process. Near the inferior portion of the articular process, the nerve ramifies itself in lateral and medial branch. The medial branch comes back around the inferior portion of the lumbar-sacrum articulation that it innervates. CONCLUSIONS: We didn't note great variations in the anatomy from L1 do L4. The L5 segment has a different distribution of the branches that should be considered when we do a percutaneous denervation procedure. The approach of the needle must touch the transverse process and feels the resistance of the articular joint . The determination of the neurotomy s point tends to become more precise denervation procedure.