Clinical And Pathological Research On Cervical Spinal Cord Injury Without Radiographic Abnormality

Objective:To retrospectively analysis the non-surgical and surgical treatment outcome of patients with cervical spinal cord injury without radiographic abnormality, and to explore its pathological mechanism. To investigate the impairment for system composed of short cervical propriospinal tracts and neurons which plays a crucial role in mechanism of cervical cord central injury around grey matter, to analyze short cervical descending/motor and ascending/sensory propriospinal tracts concerning respectively principal distribution and reciprocal correlation, to clarify the extent and trend of immune, inflammation or reparative reaction related to regeneration, reconstruction and death of soma and axon derived from short cervical propriospinal neurons after the contusion damage.Methods:(1)From January2005to March201030patients (21males,9females; mean57.5years old) with cervical spinal cord injury without radiographic abnormality were included in this study. The American spinal injury Association (ASIA) score and the Japanese Orthopaedic Association (JOA) score were reviewed before and after treatment.11cases underwent Non-surgical treatment, while19cases underwent surgical treatment, and the JOA score were compared between the two groups to evaluate the clinical outcome.(2)By means of retrograde labeling of Dextran Tetramethyl Rhodamine(DTMR), we should observe dispersal and convergence of sensory and motor propriospinal tracts affiliated to cervical upper and lower myelomeres, via establishing bilaterally dorsal compression or contusion injury model involving rat cervical enlargement, utilizing immunohistochemistry and immunofluorescence staining to survey microenvironment reactions, light microscopy combined with transferase-mediated deoxyuridine triphosphate-biotin nick end labeling and coloring to measure the change trend of immune and inflammation reaction.Results:(1)The follow-up time were10to26months with an average of18months. According to the ASIA functional classification, the sensory and motor function of majority surgical patients were improved significantly, while, partial improvement of neurological function were found in the patients with non-surgical treatment. Compared with the non-surgical treatment group, the JOA score of surgery group improved significantly (9.50±4.55,7.35±4.25; P<0.05).(2)At the time of12hours after the fifth cervical myelomere contusion, immediate or short-term apoptosis reaction happen, particularly cervical3and4myelomeres obvious, fairly weaker at cervical6,7and8consecutive myelomeres. Apoptosis, regeneration and reconstruction reactions were simultaneously induced at different time-points12and24hours after above-mentioned trauma, growth assocaited protein-43on behalf of regeneration and Caspase-3typical representative of cell death up-regulation or highly expression compared to previously intact state prior to injury, short propriospinal neurons in which cytoplasm staining with DTMR cyteblast dyeing with GAP-43and/or Casp-3were colocalized within identical area. Sensory or ascending short propriospinal tracts subordinate to cervical8spinal root principally distributed in ventral part of lateral funiculus, mostly coursed in dorsal part of lateral funiculus, which approached more closely to central canal or grey matter than motor Counterpart in process of superiorly adjacent myelomeres.Conclusions:(1) The pathological mechanisms of cervical spinal cord injury without radiographic abnormality were cervical spinal cord compression caused by trauma and resulted in spinal cord hemorrhage, edema, ischemia or nerve tissue necrosis; Timely surgical treatment after injury is better than non-surgical treatment; Early surgery treatment is necessary for patients with significant cervical spinal cord compression.(2)Primary short propriospinal tracts attached to cervical inferior myelomeres close to edge of white matter, Level two or above short propriospinal tracts close to border of grey matter, in accordance with the commonly clinical principle of central cervical cord injury of upper myelomeres followed by more easily involving short ascending and descending conduction bundles. Short sensory propriospinal tracts affiliated to cervical lower myelomeres near to ventral part of funiculus lateralis, partly overlap with short motor propriospinal tracts belong to same segment, which may interpret why sensory deficit and motor impediment(including tardive hand intrinsic muscle atrophy simultaneously occur after cervical canal decompression; series of immune, inflammation and apoptosis responses induced simultanelously and immediately after disturbance of short cervical propriospinal tracts, which conform to intensity enhance and range amplification of high signal zone on T2-weighted MRI indicative of secondarily harmful injury or the concept of’white cord syndrome; Short cervical motor propriospinal tracts attributed to upper segments far away from grey cord, that linked with lower segments draw near to grey matter, coincidence with the theory of the area surrounding grey matter located at the district of supply end of nourish vessel as well as oxygen consumption or metabolism level watershed, which result in susceptibility to exogenous, chronic, repeated or continuous stimuli, traction and irritation, opposed to array pattern of gradual(cervical,thoracic,lumbar, sacral) alternation from central canal to white cord margin for long ascending and descending tracts (cortispinal tract included);Short motor propriospinal tracts pertained to lower segments more far away from grey cord brim, corresponding sensory components considerably adjacent to grey cord, convenient for disclosing why central cord injury or cervical decompression, more often complicated by intraoperative and postoperative sensory abnormity,not frequently plagued with clumsy hands or motor function compromise to a certain degree.