Barth A. Green

Extrusion of an intervertebral disc associated with traumatic subluxation or dislocation of cervical facets. Case report.

The occurrence of a clinically significant anterior herniation of a cervical disc in association with an injury to the posterior ligaments and subluxation or dislocation of facets (zygapophyseal joints) has received sparse attention in the orthopaedic and neurosurgical literatur&358’3”5. Similarly, inadequate attention has been paid to the fact that the neurological status of a patient might worsen with increasing protrusion of the disc as the posterior displacement of the facets is corrected2’3’6. In July 1980, a patient who had dislocation of the facet joints at the sixth and seventh cervical levels and hemiation of the disc between those two vertebrae was treated at our institution, and the result was catastrophic. Since that time, we have been alert to the possibility that a herniation of a cervical disc might accompany the posterior injury. We encountered the cases of five additional patients who had these concomitant injuries. At the Jackson Memorial Hospital in Miami, Florida, from July 1980 to August 1987, we operated on sixty-eight patients who had an acute injury to the cervical posterior ligaments associated with subluxation or dislocation, or both, of facet joints. Our routine, in general, is as follows. Traction with Gardner-Wells skull-tongs is applied initially to every patient who has a posterior cervical injury. We attempt a closed reduction by gradually increasing traction. We monitor the situation with serial roentgenograms. We do not attempt a manipulative reduction. As long as the neurological status does not deteriorate, we use this method of reduction for as long as seventy-two hours and with as much as twenty-three kilograms (fifty pounds) of traction. A myelogram or a computerized tomography or magnetic resonance-imaging scan (or, often, more than one of these studies) is made during that interval to reveal whether there is hemiation of a disc. If there is no such herniation, posterior cervical wiring and arthrodesis is done after a closed reduction. If the subluxated or dislocated facet was not reduced with skull-tong traction, we perform an operative

Acute traumatic central cord syndrome: MRI-pathological correlations

SummaryThe acute traumatic central cord syndrome (ATCCS) is commonly stated to result from an injury which affects primarily the center of the spinal cord and is frequently hemorrhagic. To test the validity of this widely disseminated hypothesis, the magnetic resonance images [MRI] of 11 consecutive cases of ATCCS caused by closed injury to the spine were analyzed and correlated with the gross pathological and histological features of 3 cervical spinal cords obtained at post mortem from patients with ATCCS, including 2 of patients studied by MRI. The MRI studies were performed acutely (18 h to 2 days after injury) in 7 patients and subacutely (3–10 days after injury) in 4. Ten of the 11 patients had pre-existing spondylosis and/or canal stenosis. The 11th suffered a cervical fracture. All patients exhibited hyperintense signal within the parenchyma of the cervical spinal cord on gradient echo MRI. None showed MRI features characteristic of hemorrhage on T1-weighted spin echo or T2*-weighed gradient echo studies. Gross and histological examination of the necropsy specimens showed no evidence of blood or blood products within the cord parenchyma: the primary finding was diffuse disruption of axons, especially within the lateral columns of the cervical cord in the region occupied by the corticospinal tracts. The central gray matter was intact. In patients with ATCCS, the predominant loss of motor function in thedistal muscles of the upper limbs may reflect the importance of the corticospinal tract for hand and finger function in the primate. In this study, the MRI and pathological observations indicate that ATCCS is predominantly a white matter injury and that intramedullary hemorrhage is not a necessary feature of the syndrome; indeed, it is probably an uncommon event in ATCCS. We suggest that the most common mechanism of injury in ATCCS may be direct compression of the cervical spinal cord by buckling of the ligamenta flava into an already narrowed cervical spinal canal; this would explain the predominance of axonal injury in the white matter of the lateral columns.

Cervical sagittal spinal canal size in spine injury.

This study investigated the relationship between cervical spine sagittal canal diameter and neurologic injury in cases of spinal fracture-dislocation. A group of 98 patients with such injuries was reviewed; 45 had no neurologic deficits, 39 had incomplete quadriplegia, and 14 had complete quadriplegia. Spinal canal sagittal diameter was measured in all, and large diameter and small canals were defined. Small diameter canals were correlated significantly with neurologic injury, while large diameter canals allowed protection from neurologic injury in cervical fracture dislocation.

Oncologic and functional outcome following sacrectomy for sacral chordoma.

BACKGROUND Sacral chordoma is a rare, low to intermediate-grade tumor that poses substantial challenges in terms of timely diagnosis and adequate treatment. Few studies have examined the oncologic and functional outcomes of patients treated for sacral chordoma. METHODS The clinical records of sixteen patients who had undergone sacrectomy for chordoma between 1985 and 2001 were evaluated retrospectively. All patients underwent resection by means of a sequential combined anterior and posterior approach. Patients were followed clinically at six-month intervals following recovery from the index surgical procedure. The disease onset, treatment, hospital stay, recurrence rates, survival, adjuvant therapy, functional outcome measures, and complications were evaluated. RESULTS The average age at the time of diagnosis was sixty-one years. The mean tumor size was 15.2 cm in diameter, and all patients had a resection involving S1 or S2. The mean duration of follow-up was sixty-six months, and the tumor recurred in twelve of the sixteen patients. The mean time to metastasis was fifty months. Four patients were clinically disease-free at a mean follow-up of 94.5 months, while five patients died as a result of progressive local or metastatic disease at a mean follow-up of 31.4 months. Only one patient had normal bowel and bladder control postoperatively, and only three were able to walk without assistive devices. Eight patients had wound complications, and one patient had a deep-vein thrombosis. With the numbers available, neither negative margins at the time of initial tumor resection nor adjuvant radiation therapy had a significant impact on survival or local recurrence. More cephalad levels of resection were associated with significantly worse bowel (p = 0.01) and bladder (p = 0.01) control. Complications were frequent and were more common with a larger tumor size at the time of presentation (p = 0.034). CONCLUSIONS The treatment of sacral chordoma is an arduous clinical undertaking that requires a multidisciplinary approach and attention to detail from the outset. Despite aggressive well-planned surgical management and adherence to strict surveillance protocols, frequent recurrence and the late onset of metastatic disease are to be expected in a substantial proportion of patients, especially those with a very large chordoma or one at a more cephalad level. Adequate surgical treatment results in substantial functional impairment and numerous complications; however, it does offer the possibility of long-term disease-free survival. We advocate an attempt at complete resection, when there is still a possibility of cure, and aggressive treatment of local recurrences. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Cardiovascular findings in quadriplegic and paraplegic patients and in normal subjects

Abstract Seven normal, 7 paraplegic and 7 quadriplegic patients underwent cross-sectional cardiovascular evaluation, including recording of sitting heart rate, blood pressure and echocardiography. Quadriplegic patients had a 26% lower left ventricular (LV) mass index (75 ± 13 g/m 2 , p 2 ) or paraplegic patients (110 ± 26 g/m 2 ). Six quadriplegic patients and 3 paraplegic patients had an unusual pattern of LV posterior wall asynergy, which was associated with a significant rightward shift of the frontal-plane QRS axis (92 ± 22 ° vs 42 ± 41 °, p

Photochemically induced spinal cord injury in the rat

We have developed in the rat a minimally invasive model of reproducible spinal cord injury initiated photochemically. With the exposed spinal column intact, 560 nm irradiation of the translucent dorsal surface induces excitation of the systemically injected dye, rose Bengal, in the spinal cord microvasculature. The resultant photochemical reaction leads to vascular stasis. Histopathological changes at 7 days include hemorrhagic necrosis of the central gray matter, edematous pale-staining white matter tracts and vascular congestion. At the level of cord irradiation (T8) the entire cord thickness is necrosed except for the periphery of the anterior funiculus. Voluntary motor function is consistently lost in the subacute phase of injury.

Clinical Outcomes Using Modest Intravascular Hypothermia After Acute Cervical Spinal Cord Injury

BACKGROUNDAlthough a number of neuroprotective strategies have been tested after spinal cord injury (SCI), no treatments have been established as a standard of care. OBJECTIVEWe report the clinical outcomes at 1-year median follow-up, using endovascular hypothermia after SCI and a detailed analysis of the complications. METHODSWe performed a retrospective analysis of American Spinal Injury Association and International Medical Society of Paraplegia Impairment Scale (AIS) scores and complications in 14 patients with SCI presenting with a complete cervical SCI (AIS A). All patients were treated with 48 hours of modest (33°C) intravascular hypothermia. The comparison group was composed of 14 age- and injury-matched subjects treated at the same institution. RESULTSSix of the 14 cooled patients (42.8%) were incomplete at final follow-up (50.2 [9.7] weeks). Three patients improved to AIS B, 2 patients improved to AIS C, and 1 patient improved to AIS D. Complications were predominantly respiratory and infectious in nature. However, in the control group, a similar number of complications was observed. Adverse events such as coagulopathy, deep venous thrombosis, and pulmonary embolism were not seen in the patients undergoing hypothermia. CONCLUSIONThis study is the first phase 1 clinical trial on the safety and outcome with the use of endovascular hypothermia in the treatment of acute cervical SCI. In this small cohort of patients with SCI, complication rates were similar to those of normothermic patients with an associated AIS A conversion rate of 42.8%.

Intradural spinal arachnoid cysts in adults.

BACKGROUND Idiopathic arachnoid cysts are rare lesions not associated with trauma or other inflammatory insults. To date, there have been few large series describing the presentation and management of these lesions. METHODS Twenty-one cases of intradural spinal arachnoid cysts were identified (1994-2001). Pediatric patients and cases with antecedent trauma were excluded. There were eight women and 13 men with an average age of 52 years. Follow-up averaged 17 months. RESULTS Cysts were most commonly found in the thoracic spine (81%). Fifteen cysts were dorsal to the spinal cord and six were ventral to the spinal cord. All patients underwent laminectomy with cyst fenestration and radical cyst wall resection. Based upon intraoperative ultrasonography, four cysts were also shunted to the subarachnoid space, and seven patients had an expansile duraplasty with freeze-dried dural allograft. Of the seven patients with syringomyelia, three resolved with extramedullary cyst resection alone. Four required syrinx to subarachnoid shunting. Follow-up MRI demonstrated cyst resolution in all cases. All seven intramedullary syrinxes were decreased in size and four resolved completely. Weakness (100%), hyperreflexia (91%), and incontinence (80%) were more likely to improve than neuropathic pain (44%) and numbness (33%). One patient had increased numbness postoperatively. CONCLUSIONS Ventral cysts are more likely to cause weakness and myelopathic signs. Preoperative symptoms of neuropathic pain and numbness are less likely to improve than weakness and myelopathy. Utilizing intraoperative ultrasound to guide aggressive surgical treatment with the adjuncts of shunting and duraplasty results in a high rate of cyst and syrinx obliteration.

Clinical application of modest hypothermia after spinal cord injury.

There is widespread interest in the use of hypothermia in the treatment of CNS injury. While there is considerable experience in the use of cooling for a variety of brain pathologies, limited data exist after spinal cord injury. In the past few years, technological advances in the induction and maintenance of cooling have been achieved and can potentially allow for a more accurate evaluation of this form of treatment. We report a series of 14 patients with an average age of 39.4 years (range, 16-62 years) with acute, complete (AIS A) cervical spinal cord injuries who underwent a protocol using an intravascular cooling catheter to achieve modest (33 degrees C) systemic hypothermia. There was an excellent correlation between intravascular and intrathecal cerebrospinal fluid temperature. The average time between injury and induction of hypothermia was 9.17 +/- 2.24 h (mean +/- SEM); the time to target temperature was 2.72 +/- 0.42 h; the duration of cooling at target temperature was 47.6 +/- 3.1 h; the average total length of time of cooling was 93.6 +/- 4 h. There was a positive correlation between temperature and heart rate. Most documented adverse events were respiratory in nature. We were able to effectively deliver systemic cooling using the cooling catheters with minimal variation in body temperature. The study represents the largest, modern series of hypothermia treatment of acute spinal cord injury with intravascular cooling techniques and provides needed baseline data for outcome studies to include larger multi-center, randomized trials.

Reversal of adaptive left ventricular atrophy following electrically-stimulated exercise training in human tetraplegics

Left ventricular (LV) myocardial atrophy and diminished cardiac function have been shown to accompany chronic human tetraplegia. These changes are attributable both to physical immobilisation and abnormal autonomic circulatory regulation imposed by a spinal cord injury (SCI). To test whether exercise training increases LV mass following chronic SCI, 8 neurologically complete quadriplegic males at 2 SCI rehabilitation and research centres underwent one month of electrically-stimulated quadriceps strengthening followed by 6 months of electrically-stimulated cycling exercise. Resting M-mode and 2-D echocardiograms were measured before and after exercise training to quantify the interventricular septal and posterior wall thicknesses at end-diastole (IVSTED and PWTED, respectively), and the LV internal dimension at end-diastole (LVIDED). LV mass was computed from these measurements using standard cube function geometry. Results showed a 6.5% increase in LV IDED following exercise training (p<0.02), with increases in IVSTED and PWTED of 17.8 (p<0.002) and 20.3% (p<0.01), rspectively. Computed LV mass increased by 35% following exercise training (p=0.002). These data indicate that myocardial atrophy is reversed in tetraplegics following electrically-stimulated exercise training, and that the changes in cardiac architecture are likely to be the result of both pressure and volume challenge to the heart imposed by exercise.