Intraoperative ultrasonographic evaluation of the spinal cord in cervical myelopathy

This article describes the construction of a 15-item short-form of the Scale of Egalitarian Sex Role Attitudes (SESRA-S) based on factor analysis and examines the reliability and the validity of the short-form using data from a sample of 109 men and 93 women. SESRA-S is a self-report measure of the level of egalitarian attitudes toward the roles of men and women. Its reliability coefficient was .91, the test-retest coefficient with a four-week interval .89, and the correlation coefficient with the full form .94. These support the reliability of the short-form. Evidence of the construct validity was derived from the confirmation of five hypotheses regarding gender, educational attainment, women's employment status, age, and surname change after marriage. The findings of the present study provide evidence for the utility of the short-form as a satisfactory and time-efficient substitute for the SESRA full form.     

MRI in presumed cervical anterior spinal artery territory infarcts

20 pairs of sera from the National System of Seroepidemiological Surveillance of the triple viral vaccine received in the laboratory with febrile rash diagnosis were studied. By using the hemagglutination inhibition test, it was observed an abnormal answer of antibodies to both rubella and measles through a falling of the antibody titre in one or both diseases, or in one of them with seroconversion to the other one. With the aim of defining the existence of a possible polyclonal activation already described in literature, it was decided to study the antibody response to family Herpesviridae (HSV, EBV, CMV, VZV). 80% of answer to these viruses were found. The results are submitted and discussed.     

Percutaneous access to the anterior spinal canal through a cervical disk

We describe a CT-guided percutaneous technique for aspiration of an anterior intraspinal fluid collection through a cervical disk. The approach is identical to that of cervical diskography or percutaneous cervical diskectomy, with intentional placement of the needle tip in the spinal canal. This procedure had no adverse effects and avoided an open operation to exclude spinal cord compression.     

One-stage internal fixation and anterior fusion in complex cervical spinal disorders

The authors describe their experience with the Morscher titanium cervical plate with cancellous locking screws in the management of complex cervical spine disorders. Fifty patients (32 males and 18 females) with a mean age of 54 years (range 10 to 84 years) underwent anterior spinal fixation that extended two to five vertebral bodies, using a titanium cervical plate and autogenous bone graft. Surgeries were performed for a variety of reasons: one for a congenital lesion, five for spinal neoplasms, nine for trauma, and 35 for degenerative arthritides. Ten patients had symptomatic kyphoses due to previous laminectomy, failed anterior surgery, or trauma. Satisfactory fixation and fusion with no neurological deterioration was obtained in all but two cases. Specific complications included six cases of dysphagia, one of sepsis, one of Horner's syndrome, and one case in which the patient had a fatal myocardial infarction the night after surgery. At the end of the follow-up period, fusion was found to have occurred in all remaining cases with no outstanding implant-related problems.     

Clinical study of combined acupuncture-drug anesthesia for anterior approach cervical discectomy

OBJECTIVE: To observe the effect of combined acupuncture-drug anesthesia for anterior approach cervical discectomy. METHODS: Fifty patients scheduled for anterior approach cervical discectomy were randomized into two groups, the control group (5% procaine combined with drug anesthesia, n = 25), and the experiment group (combined acupuncture-drug anesthesia, n = 25). In the experiment group, bilateral acupoints of Neiguan (P6) and Hegu (LI4) of the patients were stimulated for 30 minutes by Hans Acupoint Nerve Stimulator through skin electrode while a combination of dolantin 25 mg and droperidol 2.5 mg were administered intravenously during induction. RESULTS: There was no statistical difference of hemodynamic variation between the two groups (P < 0.05). The experiment group could also provide the same anesthesia effect as control group did, as well as it had less postoperative complications, more rapid recovery with less expense. CONCLUSIONS: The acupuncture-drug anesthesia for anterior approach cervical discestomy is feasible and it is worthwhile to be widely used in clinical practice.     

Intraoperative electromyography during thoracolumbar spinal surgery

Intraoperative electromyography can provide useful information regarding lumbosacral nerve root function during thoracolumbar spinal surgery. Free-running electromyography provides continuous feedback regarding the location and potential for surgical injury to the lumbosacral nerve roots within the operative field. Stimulus-evoked electromyography can confirm that transpedicular instrumentation has been positioned correctly within the bony cortex. However, electromyography has a number of potential limitations, which are discussed in this article along with improved methods to increase the overall efficacy of intraoperative electromyography, including: 1) Electromyography is sensitive to blunt lumbosacral nerve root irritation or injury, but may provide misleading results with "clean" nerve root transection. 2) Electromyography must be recorded from muscles belonging to myotomes appropriate for the nerve roots considered at risk from surgery. 3) Electromyography can be effective only with careful monitoring and titration of pharmacologic neuromuscular junction blockade. 4) When transpedicular instrumentation is stimulated, an exposed nerve root should be stimulated directly as a positive control whenever possible. 5) Pedicle holes and screws should be stimulated with single shocks at low-stimulus intensities when pharmacologic neuromuscular blockade is excessive. 6) Chronically compressed nerve roots that have undergone axonotmesis (wallerian degeneration) have higher thresholds for activation from electrical and mechanical stimulation. 7) Hence, whenever axonotmetic nerve root injury is suspected, the stimulus thresholds for transpedicular holes and screws must be specifically compared with those required for the direct activation of the adjacent nerve root (and not published guideline threshold values).     

Intraoperative electroneurodiagnostics (transcranial electrical motor evoked potentials) to evaluate the functional status of anterior spinal roots and spinal nerves during brachial plexus surgery

Intradural spinal root lesions cannot be recognized by dissecting the brachial plexus and lead to ineffective surgery if they remain undetected. Therefore, patients need to undergo a diagnostic procedure to assess the intradural status of the spinal roots. Although motor recovery is the main goal of brachial plexus surgery, the techniques currently applied do not permit adequate evaluation of the anterior root. In search of an alternative, we performed intraoperative motor evoked potentials. Ninety spinal nerves in 19 patients suffering from brachial plexus lesions were dissected. Twenty-seven spinal nerves were avulsed; 8 nerves were disrupted and 17 were completely scarred, resulting in 25 stumps. Thirty-eight nerves appeared to be undamaged. On central stimulation, nerve compound action potentials were recorded from the exposed spinal nerves. Nerve compound action potentials could only be recorded from 21 stumps and from 32 apparently undamaged nerves. No recordings were obtained from 4 stumps and 7 spinal nerves in continuity. According to these findings, it is highly probable that surgery would have been insufficient in 10 spinal nerves if intraoperative motor evoked potentials had not been performed. We conclude that (1) intraoperative motor evoked potentials are an effective means for investigating the functional status of anterior motor roots and motor fibers in exposed spinal nerves, and (2) the use of motor evoked potentials should be considered during brachial plexus surgery to improve interventions.     

Thoracoscopic anterior spinal procedures in children

METHODS: From February 1996 through July 1997, 20 patients were determined to be appropriate for a thoracoscopic approach for the anterior portion of their spinal surgery. Ages ranged from 8 to 17 years of age and weight from 20 to 70 kg. The diagnosis included severe idiopathic and neurogenic scoliosis or kyphosis (n = 20) and congenital hemivertebra (n = 4). The procedures performed included diskectomy and anterior release from two to nine vertebral levels, hemivertebrectomy, and epiphysiodesis. Four patients also had an open lumbar exposure and all had a posterior fusion. RESULTS: All procedures were completed successfully endoscopically. Surgical times for the thoracoscopic portion of the procedure averaged 106 minutes and total procedure times were comparable with the standard open technique. Three patients were extubated at the end of the procedure with the majority extubated on postoperative day 1. Average intensive care unit stay was 1.8 days, and chest tubes were removed between postoperative day 1 and 5 (average, 2.2 days). In follow-up, surgical correction was deemed to be acceptable and equivalent to open techniques in all cases. CONCLUSION: This technique has proven to be safe and effective in children and appears to be associated with less pain and morbidity as evidenced by earlier extubation and chest tube removal and shorter ICU stay.     

Clinical features of transurethral anterior sphincterotomy and urological management of patients with cervical spinal cord injury

BACKGROUND: The ideal urological management for the patients with cervical spinal cord injury (CSCI) is to obtain catheter free urination and to prevent urinary tract complications. We have evaluated cases that had undergone transurethral anterior sphincterotomy from the view-point of the operative indications and the efficacy. METHODS: We carried out sphincterotomy 166 times on 133 male patients with CSCI in our Center. Before the operations were performed, all patients suffered from urinary incontinence, and they were unable to catheterize themselves for low level activity of daily life. Before and after the operation, their detrusor functions with sphincter reactions were assessed by urodynamic study. In principle we have followed up these cases by cystogram combined with cystometry, cystogram and excretory-pyelography or abdominal ultrasonography. RESULTS: In post-operative evaluations, more than 80% of cases attained hypotonic detrusor contractions and residual urine was significantly decreased. In long term follow-up, 96% of patients had obtained catheter free urination and about 85% of patients had no urinary tract complications, such as bladder deformity, vesicoureteral reflux, or hydronephrosis, with the exception of common unavoidable urinary infections. About 20% of cases had to be re-operated upon, and some cases showed hypertonic detrusor contractions or detrusor-sphincter-dyssynnergia during follow-up. CONCLUSION: The operative indications of sphincterotomy should be decided when the CSCI patients is unable to perform self-catheterization, and when due to the dysfunction of the urethral sphincter, these patients suffered from voiding difficulties or autonomic dysreflexia, or when the urinary tract complications might occur. In the majority of cases the aims of the sphincterotomy were achieved but some cases underwent another operation or had recurrent dysfunction of the urethral sphincter, indicating the need for careful follow-up.     

The importance of sonography in the diagnosis of septic complications following spinal surgery

The detection of infection after surgery on the thoracic and lumbar spine is difficult due to the anatomical circumstances. Clinical symptoms, laboratory findings, and most radiological techniques are of limited diagnostic value. Among other benefits, sonography offers the advantage of early postoperative examination, even with metal implants in the operated area. In a retrospective study, 27 patients with clinically suspicious wounds were evaluated by sonography in the postoperative follow-up; all cases were verified by puncture and/or operative revision. Eleven cases turned out to be hematomas, and 16 cases were found to be infections. Accumulations of fluid, however, could not be differentiated by the established sonomorphological criteria such as internal echo structures, septation, demarcation from the environment, and reaction of the surrounding tissue. Ultrasonically guided transcutaneous needle aspiration biopsy served to differentiate the local findings and to establish the diagnosis and therefore is required as an obligatory method of investigation.     

Intraoperative monitoring for spinal cord tumor by spinal cord evoked potential following unilateral spinal cord stimulation

We described our experiences with intraoperative spinal cord monitoring in 6 cases of spinal cord tumor. During the operation, spinal cord evoked potential following unilateral spinal cord stimulation was recorded from subdural monitoring electrodes. This series included two cases of intradural extramedullary tumor (one case each of neurinoma and of meningioma) and four cases of intramedullary tumor (2 cases of cavernous angioma, one case each of ependymoma, and of glioblastoma multiforme). Before the removal of the tumor, the spinal cord evoked potential showed lower amplitude or no response on the more affected side in all 6 cases. During the operation, the different intraoperative changes were shown on each side. The authors think that the detection of unilateral damage to the spinal cord is possible in spinal cord evoked potential using unilateral spinal cord stimulation.     

Geometric changes in the cervical spinal canal during impact

SUMMARY OF BACKGROUND DATA: Although the extent of injury after cervical spine fracture can be visualized by imaging, the deformations that occur in the spinal canal during injury are unknown. STUDY DESIGN: This study compared spinal canal occlusion and axial length changes occurring during a simulated compressive burst fracture with the residual deformations after the injury. METHODS: Canal occlusion was measured from changes in pressure in a flexible tube with fluid flowing through it, placed in the canal space after removal of the cord in cadaver specimens. To measure canal axial length, cables were fixed in C1 and led through the foramen transversarium from C2-T1, then out through the base, where they were connected to the core rods of linearly variable differential transformers (LVDT). Axial compressive burst fractures were created in each of ten cadaveric cervical spine specimens using a drop-weight, while force, distraction, and occlusion were monitored throughout the injury event. Pre- and post-injury radiographs and computed tomography scans compared transient and post-injury spinal canal geometry changes. RESULTS: In all cases, severe compressive injuries were produced. Three had an extension component in addition to compression of the vertebra and retropulsion of bone into the canal. The mean post-injury axial height loss measured from radiographs was only 35% of that measured transiently (3.1 mm post-injury, compared with 8.9 mm measured transiently), indicating significant recovery of axial height after impact. Post-injury and transient height loss were not significantly correlated (r2 = 0.230, P = 0.16) demonstrating that it is not a good measure of the extent of injury. Similarly, mean post injury canal area was 139% of the minimum area measured during impact, indicating recovery of canal space, and post-injury and transient values were not significantly correlated (r2 = 0.272, P = 0.12). Mean post-injury midsagittal diameter was 269% of the minimum transient diameter and showed a weak but significant correlation (r2 = 0.481, P = 0.03). CONCLUSIONS: Two potential spinal cord injury-causing mechanisms in axial bursting injuries of the cervical spine are occlusion and shortening of the canal. Post-injury radiographic measurements significantly underestimate the actual transient injury that occurs during impact.     

Delayed postoperative tethering of the cervical spinal cord

Tethering of the spinal cord in the lumbar and sacral regions of children with congenital anomalies is a well-recognized problem; however, tethering in the cervical region has rarely been reported. A search of the literature revealed no reports of symptomatic postoperative cervical spinal cord tethering. The authors present five cases of delayed postoperative cervical spinal cord tethering and discuss the benefit of detethering in these patients. All five patients were young (16 to 42 years of age) at presentation. All had done well after an initial surgical procedure but returned between 1 and 31 years postoperatively with symptoms including severe headache, upper-extremity pain, and progressive neurological deficits. In each case, magnetic resonance imaging indicated dorsal tethering of the cord in the cervical region. Surgical exploration with microscopic sharp detethering of the cervical cord was performed on each patient with favorable results. To avoid retethering, wide Tutoplast duraplasty is recommended.     

Transthoracic approach to the spinal column

Thoracotomy is used to approach and treat anterior spinal lesions arising from various causes. Between 1990 and 1997, we treated 56 patients (40 men and 16 women) between 14 and 67 years old (mean 38.4). All had spinal lesions that were impossible or difficult to reach by a posterior approach. Thirty-one (55.3%) had suffered spinal damage, 8 (14.3%) had spinal deformities, 7 (12.5%) had metastatic tumors, 5 (8.9%) had herniated discs, 4 (7.1%) had Pott's disease and 1 (1.8%) had osteolysis at D6. Thoracotomy was left-sided in 35 cases (62.5%) and right-sided in 19 (33.9%). Video-assisted thoracoscopy was used twice (3.6%). The level of incision was based on the site of the lesion, and the pleural cavity was opened in all cases except one. The posterolateral pleuro-diaphragmatic fold was dissected and the diaphragm opened for retroperitoneal access in 37 cases (66.1%) of thoracolumbar disease. Orthopedic treatment consisted of autologous bone grafts in all cases and placement of a Kaneda splint in 32 cases (57.1%). One patient had to undergo surgery a second time due to inappropriate placement of the vertebral splint. Pneumothorax occurred in one patient after removal of pleural drains. The incision became infected in one patient, and one case of ileal paralysis was observed. Overall, morbidity was 7.1%. We conclude that thoracotomy offers a good alternative approach to spinal lesions. Results are good and morbidity low.     

Intraoperative monitoring of the motor pathway using transtracheal stimulation of the cervical spine in dogs

Although SEP monitoring of the spinal cord has been a well established method recently, not an ultimate, perfectly developed technique for monitoring of the motor system is known so far, particularly, because of the disturbing effect of narcotic drugs and relaxants on the motor evoked potentials. In this study the upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed to the cervical spinous processes. Single and serial stimuli were applied. Recordings were obtained from the exposed right femoral nerve and quadriceps muscle. Averaging was necessary when using serial stimulations. Responses were consequent and reproducible during regular anesthesia. The origin of the different responses in the spinal cord is discussed. The method seems to be appropriate for intraoperative monitoring of the thoracolumbar spine.     

The antero-posterior diameter of the cervical spinal canal in cervical spondylosis (author's transl)

1. The antero-posterior diameter (APD) of the cervical spinal canals in 96 healthy adults, 108 cases of radiological cervical spondylosis (asymptomatic) and 96 cases of cervical spondylosis with radiculopathy or radiculomyelopathy was measured for each vertebra by the method of Burrows. (Filmfocus distance was 1.2m). 2. The APD in patients with symptomatic spondylosis was found to be significantly narrower than those of without. 3. Since the upper limit of APD at C4 to C6 vertebrae in symptomatic spondylosis was 16 mm, while the lower limit of APD in asymtomatic spondylosis was 14 mm, the following conclusion appears justified. 1) When the APD is narrower than 16 mm, the osteophytes along the posterior border of the spinal bodies or degenerative disc protrusions may produce cervical radiculomyelopathy, although the cord and the roots may escape from compression by the spondylotic changes even when the APD is wider than 14 mm. 2) When the APD is narrower than 13 mm, it is almost always certain that the osteophytes or herniated discs compress the cervical cord and roots.     

The developmental segmental sagittal diameter of the cervical spinal canal in patients with cervical spondylosis

The role of the narrow cervical spinal canal in the expression of clinical syndromes in the cervical spine was investigated in a retrospective review of 63 patients with symptomatic cervical spondylosis refractory to conservative therapy. The measurement of the developmental segmental sagittal diameter, determined at the level of the pedicle, and of the spondylotic segmental sagittal diameter, determined at the level of the disc, were applied. When divided into groups based on anatomic variance around an average size midcervical diameter of 17 mm, 40 patients were found to have less than the average size of midcervical canal. A spondylosis index was computed for the narrow canal group at 2.08 mm per segment and for the wide canal group at 3.29. Canal dimensions are determinants of symptom production and neurologic compromise.