Experimental chronic compressive cervical myelopathy: effects of decompression

1995 ◽  
Vol 83 (2) ◽  
pp. 336-341 ◽  
Author(s):  
H. Louis Harkey ◽  
Ossama Al-Mefty ◽  
Isam Marawi ◽  
Dudley F. Peeler ◽  
Duane E. Haines ◽  
...  
Keyword(s):  
Cervical Myelopathy ◽  
Disease Process ◽  
Cord Compression ◽  
Magnetic Resonance Images ◽  
Pathological Examination ◽  
Cervical Cord ◽  
Spinal Cord Blood Flow ◽  
Flow Measurements ◽  
Content Type ◽  
Fine Print

✓ Twelve dogs developed a delayed onset of neurological abnormalities from chronic cervical cord compression that was characteristic of myelopathy. The animals were divided into two groups and matched according to degree of neurological deficit. Six animals underwent decompression through removal of the anteriorly placed compressive device. Throughout the experiment, serial neurological examinations and somatosensory evoked potential studies were performed on each animal. Spinal cord blood flow measurements were obtained during each surgical procedure and at sacrifice. Magnetic resonance images were obtained after compression and before sacrifice. All animals in the decompressed group showed significant neurological improvement after decompression; no spontaneous improvement in neurological function was seen in the compressed group. On pathological examination, irreversible changes including large motor neuron loss, necrosis, and cavitation were seen in four of the animals in the decompressed group and five in the compressed group. Cervical spondylotic myelopathy in humans is known to respond to decompression; this study provides further evidence that this animal model for chronic compressive cervical myelopathy accurately reflects the disease process seen in humans.

Experimental chronic compressive cervical myelopathy

1993 ◽  
Vol 79 (4) ◽  
pp. 550-561 ◽  
Author(s):  
Ossama Al-Mefty ◽  
H. Louis Harkey ◽  
Isam Marawi ◽  
Duane E. Haines ◽  
Dudley F. Peeler ◽  
...  
Keyword(s):  
Blood Flow ◽  
Spinal Canal ◽  
Morphological Changes ◽  
Clinical Signs ◽  
Magnetic Resonance Images ◽  
Neurological Deficits ◽  
Cervical Cord ◽  
Flow Measurements ◽  
Content Type ◽  
Fine Print

✓ A canine model simulating both cervical spondylosis and its results in delayed progressive myelopathy is presented. This model allowed control of compression, an ongoing assessment of neurological deficits, and evaluation using diagnostic images, frequent electrophysiological tests, local blood flow measurements, and postmortem histological examinations. Subclinical cervical cord compression was achieved in 14 dogs by placing a Teflon washer posteriorly and a Teflon screw anteriorly, producing an average of 29% stenosis of the spinal canal. Four dogs undergoing sham operations were designated as controls. Twelve of the animals undergoing compression developed delayed and progressive clinical signs of myelopathy, with a mean latent period to onset of myelopathy of 7 months. Spinal cord blood flow studies using the hydrogen clearance method showed a significant transient increase in blood flow immediately after compression and a decrease before sacrifice. Somatosensory evoked potential studies indicated progressive deterioration during the period of compression. Magnetic resonance images revealed intramedullary changes. Histological studies showed abnormalities overwhelmingly within the gray matter, including changes in vascular morphology, loss of large motor neurons, necrosis, and cavitation. Axonal degeneration and obvious demyelination were rarely seen. The most profound morphological changes occurred at the site of greatest compression. It is proposed that a momentary arrest of microcirculation occurs during extension of the neck because of loss of the reserve space in the compromised spinal canal. This microcirculatory disturbance is predominant in the watershed area of the cord and mainly affects the highly vulnerable anterior horn cells, leading to neuronal death, necrosis, and eventual cavitation at the junction of the dorsal and anterior horns. Additional supportive evidence of this hypothesis was derived from the literature.

Experimental cervical myelopathy

1975 ◽  
Vol 43 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Michael R. Gooding ◽  
Charles B. Wilson ◽  
Julian T. Hoff
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cervical Myelopathy ◽  
Cervical Spondylosis ◽  
Local Deformation ◽  
Cervical Cord ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Adjacent Segments ◽  
Fine Print

✓ The authors report experiments designed to test the effect of regional ischemia induced by selective vascular ligations and anterior compression of the cervical cord at two adjacent segments (C-4, C-5) in the same dog. They conclude that local ischemia of the cervical cord, caused by local deformation, when superimposed on a regional reduction in spinal cord blood flow, accounts for the myelopathy of cervical spondylosis whether produced experimentally in animals or occurring naturally in man.

Vertical translocation: the enigma of the disappearing atlantodens interval in patients with myelopathy and rheumatoid arthritis. Part I. Clinical, radiological, and neuropathological features

1997 ◽  
Vol 87 (6) ◽  
pp. 856-862 ◽  
Author(s):  
Adrian T. H. Casey ◽  
H. Alan Crockard ◽  
Jennian F. Geddes ◽  
John Stevens
Keyword(s):  
Cervical Myelopathy ◽  
Survival Rates ◽  
Cord Compression ◽  
Atlantoaxial Subluxation ◽  
Lateral Mass ◽  
Progressive Decrease ◽  
Content Type ◽  
Statistical Comparison ◽  
High Cervical ◽  
Fine Print

✓ This statistical comparison between patients with cervical myelopathy secondary to horizontal atlantoaxial subluxation and those with vertical translocation is designed to elucidate the mechanisms responsible for cranial settling and the effect of translocation on the development of spinal cord compression. In a 10-year study of a cohort of 256 patients, 186 suffered from myelopathy and 116 (62%) of these exhibited vertical translocation according to the Redlund-Johnell criteria. Vertical translocation occurred after a significantly longer period of disease than atlantoaxial subluxation (p < 0.001). Translocation was characterized clinically by a high cervical myelopathy with features of a cruciate paralysis present in 35% of individuals compared with 26% who exhibited horizontal atlantoaxial subluxation (p = 0.29), but there was a surprising paucity of cranial nerve problems. The patients with vertical translocation had a greater degree of neurological disability (p = 0.002) and poorer survival rates (p = 0.04). Radiologically, vertical translocation was secondary to lateral mass collapse and associated with a progressive decrease in the atlantodens interval ([ADI], r = 0.4; p < 0.001) and pannus (p = 0.003). Thirty percent of patients exhibited an ADI of less than 5 mm. This phenomenon has been termed pseudostabilization. The authors' studies emphasize that the ADI (frequently featured in the literature) is totally unreliable as an indicator of neuraxial compromise in the presence of vertical translocation.

Symptomatic hydrocephalus and reversible spinal cord compression in Listeria monocytogenes meningitis

1989 ◽  
Vol 71 (4) ◽  
pp. 620-622 ◽  
Author(s):  
Eric C. Raps ◽  
David H. Gutmann ◽  
James R. Brorson ◽  
Michael O'Connor ◽  
Howard I. Hurtig
Keyword(s):  
Spinal Cord ◽  
Listeria Monocytogenes ◽  
Cord Compression ◽  
Cervical Cord ◽  
Communicating Hydrocephalus ◽  
Ventricular Drainage ◽  
Central Nervous System Infections ◽  
Content Type ◽  
Clinical Syndromes ◽  
Fine Print

✓ Central nervous system infections with Listeria monocytogenes result in varied clinical syndromes ranging from meningitis to rhomboencephalitis. A case of Listeria meningitis complicated by symptomatic communicating hydrocephalus and hydrostatic cervical cord compression is presented which clinically and radiographically improved with aggressive ventricular drainage.

Cervical flexion myelopathy: a “tight dural canal mechanism”

1987 ◽  
Vol 66 (6) ◽  
pp. 935-937 ◽  
Author(s):  
Yoshinobu Iwasaki ◽  
Kunio Tashiro ◽  
Seiji Kikuchi ◽  
Mayumi Kitagawa ◽  
Toyohiko Isu ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Cord Compression ◽  
Cervical Cord ◽  
Posterior Border ◽  
Disc Disease ◽  
Content Type ◽  
Neuroradiological Examination ◽  
Cervical Flexion Myelopathy ◽  
Progressive Weakness ◽  
Fine Print

✓ The authors describe a case of flexion myelopathy due to specific morphological changes of the cervical cord, termed a “tight dural canal mechanism.” The patient was an 18-year-old man with progressive weakness and muscle atrophy of the left arm. Neuroradiological examination revealed that the lower cervical cord was compressed during flexion of the cervical spine, but that there was no disc disease or cervical vertebral instability. The cord compression was attributed to a pinching mechanism by the posterior border of the vertebral body and the posterior component of the dura on flexion.

Spinal Cord Blood Flow in Experimental Transient Traumatic Paraplegia

1980 ◽  
Vol 52 (3) ◽  
pp. 335-345 ◽  
Author(s):  
Dean C. Lohse ◽  
Howard J. Senter ◽  
John S. Kauer ◽  
Richard Wohns
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Spinal Cord Blood Flow ◽  
Flow Measurements ◽  
Content Type ◽  
The Mean ◽  
Blood Flow Measurements ◽  
Fine Print

✓ Blood flow in the lateral funiculus of the thoracic spinal cord was measured in 24 anesthetized cats using the hydrogen clearance method. In a control series of eight nontraumatized animals, blood flow measurements were taken from the T-5 and T-6 segments for 6 consecutive hours. The mean spinal cord blood flow (SCBF) in the control group was 12.8 ± 3.51 (SD) ml/min/100 gm on the basis of 107 measurements over 6 hours. In the experimental groups, 16 animals were similarly prepared. The spinal cords of these animals were then traumatized by dropping a 20-gm weight 5 cm (100 gm-cm trauma) or 13 cm (260 gm-cm trauma) onto the T-5 segment. Previous experiments have shown that these trauma levels lead to a transient paraplegia of less than 10 and 30 days' duration, respectively. Two hundred blood flow measurements from T-5 and T-6 were taken over the 6 hours following trauma. In the seven animals of the 100 gm-cm group, mean SCBF after trauma from the T-5 segment was 12.6 ± 3.45 (SD) ml/min/100 gm on the basis of 50 measurements taken over 6 hours; not significantly different from the controls (p > 0.70). In the 260 gm-cm group, mean SCBF from T-5 for 6 hours after trauma was 17.3 ± 6.60 (SD) ml/min/100 gm; significantly higher than controls (p < 0.001). Mean SCBF 3 to 6 hours after trauma was significantly elevated over controls (p < 0.05). The mean hyperemia in the 260 gm-cm group was found to be due to marked hyperemia in only four animals of the series, while five animals maintained blood flows in the normal range. This experiment provides quantitative evidence that white matter ischemia does not occur in spinal cord injuries that can be expected to produce only transient paraplegia. The data support the concept that white matter ischemia in the acute phase of severe spinal cord trauma may be related to secondary injury and subsequent permanent paraplegia.

Symptomatic subependymoma: a clinicopathological and flow cytometric study

1991 ◽  
Vol 75 (4) ◽  
pp. 583-588 ◽  
Author(s):  
Daniela Lombardi ◽  
Bernd W. Scheithauer ◽  
Fredric B. Meyer ◽  
Glenn S. Forbes ◽  
Edward G. Shaw ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Lateral Ventricle ◽  
Magnetic Resonance Images ◽  
Pathological Examination ◽  
Dystrophic Calcification ◽  
Content Type ◽  
Cytological Atypia ◽  
Postoperative Irradiation ◽  
Fine Print

✓ Twenty-one intracranial subependymomas were reviewed with regard to presentation, diagnosis, operative findings, and long-term follow-up data. The histopathological features were critically reviewed, and deoxyribunucleic acid analysis was performed by flow cytometry. The patients' mean age was 48.5 years (range 32 to 72 years). In 14 cases the tumor was located in the fourth ventricle, in six within a lateral ventricle, and in one in the third ventricle with extension into the lateral ventricle. Radiographic characteristics included isodensity with minimal enhancement on computerized tomography, frequent dystrophic calcification, and isointensity on T1-weighted or slight hyperintensity on T2-weighted magnetic resonance images. The predominant histological features in all cases were those of classic subependymoma. Nonetheless, pathological examination showed a minor (< 20%) ependymoma component in five cases, significant cytological atypia in seven, mitoses in 11, endothelial prominence in four, and focal hemorrhage-associated necrosis in two. Flow cytometry revealed a diploid pattern in 12 patients, tetraploidy in two, and aneuploidy in one. Two patients died in the perioperative period. Of the remaining 19, 12 underwent gross total resection (two of whom received postoperative irradiation) and seven underwent subtotal resection (five of whom received irradiation). None of the 12 non-irradiated patients developed tumor progression or died of direct tumor-related causes. Of the seven irradiated patients, follow-up imaging studies demonstrated their tumors to be radioresponsive, particularly with doses of 5000 cGy or greater. Despite the presence of cytological atypia and mitotic activity in the majority of cases, the prognostic effects of such factors as tumor location and the extent of surgical resection outweighed those of the standard histopathological parameters. Routine postoperative irradiation is not recommended, but should be reserved for cases with a symptomatic residual or recurrent subependymomas following surgery.

Cervical cord compression due to a hypoplastic atlas

2001 ◽  
Vol 94 (1) ◽  
pp. 133-136 ◽  
Author(s):  
Daniel May ◽  
Benoît Jenny ◽  
Antonio Faundez
Keyword(s):  
Cord Compression ◽  
Cervical Cord ◽  
Posterior Decompression ◽  
Late Adulthood ◽  
Content Type ◽  
Cervical Cord Compression ◽  
Sagittal Diameter ◽  
Fine Print

✓ The authors report the case of a 66-year-old man with progressive, nontraumatic, C-1 cord compression who presented with a complete but hypoplastic atlas. They review six cases found in the literature. Symptoms usually develop in the late adulthood; the sagittal diameter of the canal measures 10 mm or less. The treatment requires a posterior decompression. Opening of the dura is sometimes necessary. There is no pressing need for a primary stabilization device.

Acute cervical cord injury without fracture or dislocation of the spinal column

2000 ◽  
Vol 93 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Izumi Koyanagi ◽  
Yoshinobu Iwasaki ◽  
Kazutoshi Hida ◽  
Minoru Akino ◽  
Hiroyuki Imamura ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Cervical Spine ◽  
Spinal Canal ◽  
Spinal Column ◽  
Cord Compression ◽  
Cervical Cord ◽  
Content Type ◽  
Cord Injury ◽  
Cervical Cord Injury ◽  
Fine Print

Object. It is known that the spinal cord can sustain traumatic injury without associated injury of the spinal column in some conditions, such as a flexible spinal column or preexisting narrowed spinal canal. The purpose of this study was to characterize the clinical features and to understand the mechanisms in cases of acute cervical cord injury in which fracture or dislocation of the cervical spine has not occurred. Methods. Eighty-nine patients who sustained an acute cervical cord injury were treated in our hospitals between 1990 and 1998. In 42 patients (47%) no bone injuries of the cervical spine were demonstrated, and this group was retrospectively analyzed. There were 35 men and seven women, aged 19 to 81 years (mean 58.9 years). The initial neurological examination indicated complete injury in five patients, whereas incomplete injury was demonstrated in 37. In the majority of the patients (90%) the authors found degenerative changes of the cervical spine such as spondylosis (22 cases) or ossification of the posterior longitudinal ligament (16 cases). The mean sagittal diameter of the cervical spinal canal, as measured on computerized tomography scans, was significantly narrower than that obtained in the control patients. Magnetic resonance (MR) imaging revealed spinal cord compression in 93% and paravertebral soft-tissue injuries in 58% of the patients. Conclusions. Degenerative changes of the cervical spine and developmental narrowing of the spinal canal are important preexisting factors. In the acute stage MR imaging is useful to understand the level and mechanisms of spinal cord injury. The fact that a significant number of the patients were found to have spinal cord compression despite the absence of bone injuries of the spinal column indicates that future investigations into surgical treatment of this type of injury are necessary.

Anomalous vertebral artery—induced cervical cord compression causing severe nape pain

2001 ◽  
Vol 95 (1) ◽  
pp. 146-149 ◽  
Author(s):  
Kei Watanabe ◽  
Kazuhiro Hasegawa ◽  
Kou Takano
Keyword(s):  
Spinal Cord ◽  
Rare Case ◽  
Cord Compression ◽  
Cervical Cord ◽  
Resonance Imaging ◽  
Content Type ◽  
Cervical Cord Compression ◽  
Vertebral Arteries ◽  
Signal Void ◽  
Fine Print

✓ The authors describe a very rare case of cervical cord compression caused by anomalous bilateral vertebral arteries (VAs). A 65-year-old woman had been suffering from intractable nape pain and torticollis. Magnetic resonance imaging revealed a signal void region in which spinal cord compression was present. Angiography demonstrated anomalous bilateral VAs compressing the spinal cord. Microvascular decompressive surgery was successfully performed. Neuroradiological and intraoperative findings are presented.

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