Analysis of the composition of the wave of the dorsal surface potential of the spinal cord in rats with ascending tetanus and a paroxysmal syndrome

In teleost fishes, unlike many other vertebrates, the spinal cord originates as a solid structure, the neural keel, which subsequently hollows out. Unlike vertebrates in which the neural tube is formed from neural folds, and where the neural crest arises from wedge-shaped masses of tissue connecting the neural tube to the general ectoderm, teleosts do not possess a clear morphological neural crest. Initially, the dorsal surface of the keel is broadly attached to the ectoderm as described by Shepard (1961). As the neural primordia become larger and more discrete, the region of attachment narrows, and cells become loose (the ‘loose crest stage’). These cells represent the neural crest. Subsequently they begin to migrate and to differentiate into the various derivatives of neural crest. Both sensory and sympathetic neurons arise from neural crest. At the time of their migration the cells are not morphologically distinguishable.

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Microangioarchitecture of the feline spinal cord

Journal of Neurosurgery ◽

10.3171/jns.1987.66.3.0447 ◽

1987 ◽

Vol 66 (3) ◽

pp. 447-452 ◽

Cited By ~ 15

Author(s):

Yutaka Naka ◽

Toru Itakura ◽

Kunio Nakai ◽

Kazuo Nakakita ◽

Harumichi Imai ◽

...

Keyword(s):

Spinal Cord ◽

Dorsal Surface ◽

Ventral Surface ◽

Anterior Spinal Artery ◽

Corrosion Casts ◽

Thoracic Spinal Cord ◽

Content Type ◽

Thoracic Spinal ◽

Fine Print ◽

Anterior Median

✓ The microangioarchitecture of corrosion casts of the cat spinal cord was studied by scanning electron microscopy. On the ventral surface of the spinal cord, the anterior spinal artery and the anterior spinal vein ran parallel along the anterior median fissure. Many central arteries branching from the anterior spinal artery coursed in a wavelike manner in the anterior median fissure. The number of central arteries was lowest in the thoracic spinal cord. Central arteries at some spinal cord levels revealed well-developed anastomoses with other central arteries in the anterior median fissure. These well-developed anastomotic central arteries were frequently observed in the thoracic spinal cord, in which the number of central arteries was lowest. On the dorsal surface of the spinal cord, the posterior spinal vein ran longitudinally at the midline and was drained by circumferential veins and posterior central veins. This vein formed a characteristic anastomotic plexus. Small arterioles (20 µm in diameter) in the spinal parenchyma revealed a ring-like compression at the branching site.

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Spinal intramedullary cavernomas. Personal experience reffering to six cases

Romanian Neurosurgery ◽

10.2478/romneu-2014-0056 ◽

2014 ◽

Vol 21 (4) ◽

pp. 407-415 ◽

Cited By ~ 1

Author(s):

G. Iacob ◽

Angela Olarescu

Keyword(s):

Spinal Cord ◽

Dorsal Surface ◽

Neurological Status ◽

Duration Of Symptoms ◽

Cavernous Malformations ◽

Excellent Outcome ◽

Presenting Symptoms ◽

Asymptomatic Patients ◽

Microsurgical Techniques

Abstract Despite cavernous malformations of the CNS are pathologically similar, intramedullary cavernous malformations are very rare lesions, increasingly recognized after introduction of magnetic resonance image, generating gradual neurological decline, with severe deficits or acute loss of spinal function. We report our experience on six patients with intramedullary cavernomas defining the spectrum of presenting symptoms and signs analyzing the role of surgery as a treatment for these lesions. We present our experience with 2 cervical and 4 thoracal spinal intramedullary cavernoma from 2010 to 2014 searching history, onset of clinical manifestation, neurological status, radiological findings, operation, and clinical outcome. Among 6 patients male were 2 cases; female 4 cases; mean age was 42 years (range 25-72 years); mean duration of symptoms were 1,5 years (range 5 days and 2 years) with slowly progressive neurological decline. In two cases there was acute onset of neurological compromise. In all cases diagnosis was made on MRI and lesions were possible to be radically excised and gently extracted from the hemosiderin-stained bed inside of the spinal cord via a laminectomy and midline myelotomy with microsurgical techniques. The surgical outcome on a mean duration of follow up of 12 months were: for 4 cases - the patients neurological conditions remarkably improved 1 month later, for 2 cases no improvement were remarked. No recurrent hemorrhages were recorded. A follow-up MRI examination was made in all cases to confirm complete removal of the cavernous angioma. Spinal intramedullary cavernoma should be early recognized by MRI, can be positioned in a precarious position and generate significant neurologic deficits than cranial cavernomas. For symptomatic intramedullary cavernous malformations extended to the dorsal surface of the spinal cord, total resection with microsurgical techniques can offer good or excellent outcome, restoring neurological status and to stop chronic deterioration and acute rebleeding. To asymptomatic patients with deeper lesions which entail a higher operative risk, but also a surgically manageable cause of myelopathy a closed observation is mandatory.

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Fictive locomotion and scratching inhibit dorsal horn neurons receiving thin fiber afferent input

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2000.279.2.r394 ◽

2000 ◽

Vol 279 (2) ◽

pp. R394-R403 ◽

Cited By ~ 13

Author(s):

A. M. Degtyarenko ◽

M. P. Kaufman

Keyword(s):

Spinal Cord ◽

Dorsal Horn ◽

Tibial Nerve ◽

Dorsal Surface ◽

Fictive Locomotion ◽

Thin Fiber ◽

Group Iii ◽

Dorsal Horn Neurons ◽

The Mean ◽

Stimulation Of

In decerebrate paralyzed cats, we examined the effects of two central motor commands (fictive locomotion and scratching) on the discharge of dorsal horn neurons receiving input from group III and IV tibial nerve afferents. We recorded the impulse activity of 74 dorsal horn neurons, each of which received group III input from the tibial nerve. Electrical stimulation of the mesencephalic locomotor region (MLR), which evoked fictive static contraction or fictive locomotion, inhibited the discharge of 44 of the 64 dorsal horn neurons tested. The mean depth from the dorsal surface of the spinal cord of the 44 neurons whose discharge was inhibited by MLR stimulation was 1.77 ± 0.04 mm. Fictive scratching, evoked by topical application of bicuculline to the cervical spinal cord and irritation of the ear, inhibited the discharge of 22 of the 29 dorsal horn neurons tested. Fourteen of the twenty-two neurons whose discharge was inhibited by fictive scratching were found to be inhibited by MLR stimulation as well. The mean depth from the dorsal surface of the cord of the 22 neurons whose discharge was inhibited by fictive scratching was 1.77 ± 0.06 mm. Stimulation of the MLR or the elicitation of fictive scratching had no effect on the activity of 22 dorsal horn neurons receiving input from group III and IV tibial nerve afferents. The mean depth from the dorsal surface of the cord was 1.17 ± 0.07 mm, a value that was significantly ( P < 0.05) less than that for the neurons whose discharge was inhibited by either MLR stimulation or fictive scratching. We conclude that centrally evoked motor commands can inhibit the discharge of dorsal horn neurons receiving thin fiber input from the periphery.

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Reflex activity and axonal conduction in the L-7 spinal cord segment following experimental compression trauma

Journal of Neurosurgery ◽

10.3171/jns.1985.62.6.0898 ◽

1985 ◽

Vol 62 (6) ◽

pp. 898-905 ◽

Cited By ~ 6

Author(s):

Amadeo C. Nacimiento ◽

Matthias Bartels ◽

Hans-Dietrich Herrmann ◽

Friedrich Loew

Keyword(s):

Spinal Cord ◽

Structural Changes ◽

Dorsal Surface ◽

Dorsal Column ◽

Reflex Activity ◽

Partial Recovery ◽

Content Type ◽

Axonal Conduction ◽

Spinal Cord Segment ◽

Polysynaptic Reflex

✓ In cats in which the spinal cord was transected at C-1, the exposed L-7 spinal cord segment was compressed with an electromagnetically driven rod applied to the dorsal surface of the segment. With the magnitude of compression constant at 3 mm, the cord was compressed for durations of 50 msec, 0.5 sec, or 1.0 sec. Polysynaptic reflex discharges integrated in the injured segment and action potentials conducted in dorsal column axons traversing the same region were electrophysiologically measured before, during, and for 4½ hours after trauma. Structural changes were evaluated on frozen serial sections obtained both from compressed segments and from tissue adjacent to the injury. At a compression duration of 50 msec, the amplitude of evoked reflex activity decreased abruptly, and dorsal column axonal conduction was blocked for 1 minute following compression. This early-phase response was followed by partial recovery of both functions which persisted until the end of the experiment. Prolonging compression to 0.5 sec brought about a further decrease of polysynaptic reflex activity. Axonal conduction was also decreased, but not significantly. With compression lasting 1.0 sec, no significant changes in reflex discharges and axonal conduction occurred compared with those measured at 0.5 sec. Neither function was abolished, even after the longest compression time. Prolongation of compression significantly increased both the intensity and the spread of edema, whereas changes in hemorrhage were not significant. Thus, a plateau rather than a progressive increase in severity of functional and structural posttraumatic changes was reached by increasing the duration of compression. This injury model reduces the sources of variability found in other experimental compression trauma models and permits the quantitative assessment of basic spinal cord mechanisms and correlated histopathological changes in the same preparation following trauma.

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Models of Spinal Cord Injury: Part 1

Neurosurgery ◽

10.1227/00006123-198611000-00006 ◽

1986 ◽

Vol 19 (5) ◽

pp. 752-762 ◽

Cited By ~ 38

Author(s):

Black Perry ◽

S. Markowitz Ronald ◽

Cooper Viraf ◽

Mechanic Alan ◽

Kushner Harvey ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Motor Function ◽

Dura Mater ◽

Static Load ◽

Dorsal Surface ◽

Sprague Dawley ◽

Inclined Plane ◽

Cord Injury ◽

Extent Of Damage

Abstract Testing of potential therapies for spinal cord injury has been significantly hampered by the unavailability of a standardized, reproducible animal model with predictable outcome at a given force of injury (dose-response). The rat was selected in the development of this model in preference to larger animals for economy and availability; this permits use of large numbers of animals to increase statistical validity. In the experiments reported in this article, a static load method (weight placed gently on cord) of inducing cord injury was evaluated. A total of 198 Sprague-Dawley rats were used. Under general anesthesia, a one-level laminectomy was carried out at T-12 with the dura mater intact. Weights varying from 80 to 150 g were lowered onto the dorsal surface of the intact dura mater for durations of 0 to 300 seconds. Recovery of motor function was assessed for up to 8 weeks using two behavioral tests, a modified Tarlov scale and an inclined plane test of hind limb motor function. A statistically significant relationship was found between force of injury and motor recovery as measured by the Tarlov scale, but this did not correlate with inclined plane performance; the duration that the weight rested on the cord did not influence outcome. Pathologically, there was variation in the extent of damage for a given injury load. A semiquantitative pathological assessment of cord injury showed a statistically significant correlation between pathological score and behavioral deficit as measured by the Tarlov scale, but this did not correlate with inclined plane performance. In view of these deficiencies, the static load technique does not seem to be an ideal model for spinal cord injury research.

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Two-stage Operation for Resection of Spinal Cord Astrocytomas:Technical Case Report of Three Cases

Operative Neurosurgery ◽

10.1227/01.neu.0000208965.41531.a3 ◽

2006 ◽

Vol 58 (suppl_4) ◽

pp. ONS-E373-ONS-E373 ◽

Cited By ~ 7

Author(s):

Kazutoshi Hida ◽

Yoshinobu Iwasaki ◽

Toshitaka Seki ◽

Shunsuke Yano

Keyword(s):

Spinal Cord ◽

Neurological Deficit ◽

Dorsal Surface ◽

Position Sense ◽

Joint Position Sense ◽

Low Grade ◽

Two Stage ◽

Intramedullary Tumors ◽

Intramedullary Spinal Cord ◽

Exophytic Tumor

Abstract Objective and Importance: Surgery for excision of intramedullary spinal cord tumors without increasing neurological deficit is one of the more difficult operations in spinal surgery. In particular, infiltrating astrocytomas without a clear cleavage between the tumor and normal spinal cord parenchyma are difficult to remove totally without producing additional neurological impairment. In this study, we describe a two-stage resection facilitating total resection of intramedullary tumors. Clinical Presentation: Three cases of spinal cord astrocytomas were treated using a two-staged method. Technique: The first surgery included myelotomy, biopsy and duroplasty. A thin expanded polytetrafluoroethylene sheet was placed between the dorsal surface of the spinal cord and dura mater to prevent adhesions. Two or 3 weeks after surgery, a second surgery was performed to remove the now exophytic tumor. Results: Magnetic resonance imaging scans showed exophytic extrusion of the tumor in all three cases before the second operation. In each patient, we were able to carry out gross total removal of the tumors without additional neurological deficit except for transient joint position sense loss in one case. All three patients remain neurologically stable without evidence of tumor recurrence more than 3 years after surgery. Conclusion: A two-stage operation may enhance the surgeon's ability to completely resect extensive low-grade spinal cord astrocytomas and, at the same time preserve neurological function.

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A Transmedullary Approach to Occlusion of a Ventral Perimedullary Arteriovenous Fistula of the Thoracic Spinal Cord

Neurosurgery ◽

10.1227/01.neu.0000365365.10977.48 ◽

2010 ◽

Vol 66 (3) ◽

pp. 611-615 ◽

Cited By ~ 3

Author(s):

Alf Giese ◽

Peter A. Winkler ◽

Christian Schichor ◽

Sven Rainer Kantelhardt ◽

Tobias Boeckh-Behrens ◽

...

Keyword(s):

Spinal Cord ◽

Arteriovenous Fistula ◽

Dorsal Surface ◽

Venous Drainage ◽

Venous Flow ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Complete Obliteration ◽

Fistula Site ◽

Ventral Spinal Cord

Abstract OBJECTIVE A spinal perimedullary arteriovenous fistula (PMAVF) is a direct fistula of one or more spinal arteries into the perimedullary venous network with reversed venous flow and subsequent venous congestion of the spinal cord. The therapeutic goal of surgery is to normalize the venous drainage by obliterating the fistula. Strictly ventral lesions typically require an anterior approach to ensure adequate exposure of the fistula as well and the preservation of the physiological blood supply to the spinal cord. CLINICAL PRESENTATION We present a case of a ventral PMAVF at the level of T10 with feeders from the anterior spinal artery, caudally draining veins on the ventral spinal cord, and a dilated transmedullary vein filling cranially draining veins on the dorsal aspect of the spinal cord. TECHNIQUE The dilated transmedullary vein was approached by a laminectomy. The vein was coagulated, and the gliotic channel was used to approach the ventral fistula site from the dorsal surface of the spinal cord. Complete obliteration of the fistula was achieved, and the preoperative neurological deficit improved. CONCLUSION We conclude that transmedullarly draining veins offers a possible dorsal approach for the occlusion of some ventral PMAVFs, thus avoiding more complex anterior approaches to the ventral spinal cord.

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