Histopathological changes following removal of the perineurium

1980 ◽  
Vol 53 (2) ◽  
pp. 233-238 ◽  
Author(s):  
John A. Nesbitt ◽  
Robert D. Acland
Keyword(s):  
Transverse Section ◽  
Degenerative Changes ◽  
Histopathological Changes ◽  
Content Type ◽  
Microsurgical Techniques ◽  
Sciatic Nerves ◽  
Fine Print ◽  
Perineurial Sheath

✓ Using microsurgical techniques, the perineurial sheath was stripped off the sciatic nerves of rats over a 0.5 cm length at a point where the nerve consists of a single fascicle. The nerves were excised 0 to 84 days after the injury, and were examined in semi-thin transverse section. A new sheath, closely resembling normal perineurium, became organized during the first 10 days; it appeared uniformly over the length of the injured segment. The new perineurial sheath was probably formed by endoneurial fibroblasts migrating from within the fascicle. In undamaged specimens, the axons immediately beneath the excised perineurium underwent no degenerative changes.

Accelerated spondylotic changes adjacent to the fused segment following central cervical corpectomy: magnetic resonance imaging study evidence

2004 ◽  
Vol 100 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Vaijayantee Kulkarni ◽  
Vedantam Rajshekhar ◽  
Lakshminarayan Raghuram
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Imaging Study ◽  
Degenerative Changes ◽  
Adjacent Segment ◽  
Mr Images ◽  
Short Term ◽  
Content Type ◽  
Fine Print

Object. The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging. Methods. Preoperative and short-term follow-up (mean duration 17.5 months, range 10–48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classifed as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes. Conclusions. On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.

The fine anatomy of the human spinal meninges

1988 ◽  
Vol 69 (2) ◽  
pp. 276-282 ◽  
Author(s):  
David S. Nicholas ◽  
Roy O. Weller
Keyword(s):  
Spinal Cord ◽  
Blood Vessels ◽  
Transverse Section ◽  
Human Cerebral Cortex ◽  
Pia Mater ◽  
Content Type ◽  
Inner Aspect ◽  
Dentate Ligament ◽  
Arachnoid Mater ◽  
Fine Print

✓ The fine anatomy of the human spinal meninges was examined in five postmortem spinal cords taken within 12 hours after death from patients aged 15 months to 46 years. Specimens of spinal cord were viewed in transverse section and from the dorsal and ventral aspects by scanning electron microscopy. Transverse sections of spinal cord and meninges were also examined by light microscopy. The arachnoid mater was seen to be closely applied to the inner aspect of the dura. An intermediate fenestrated leptomeningeal layer was observed attached to the inner aspect of the arachnoid mater and was reflected ventrally to form a series of dorsal septa. As it arborized laterally over the surface of the cord to surround nerves and blood vessels, the intermediate layer became highly fenestrated but remained distinct from the pia and arachnoid mater. The pia mater appeared to form a continuous layer which was reflected off the surface of the cord to coat blood vessels within the subarachnoid space in a manner similar to that described in the leptomeninges over the human cerebral cortex. Each dentate ligament consisted of a collagenous core which was continuous with the subpial connective tissue and was attached at intervals to the dura; pia-arachnoid cells coated the surface of the dentate ligaments. The present study suggests that the fine anatomy of the human spinal meninges differs significantly from that described in other mammals.

Anatomical data on the craniocervical junction and their correlation with degenerative changes in 30 cadaveric specimens

2005 ◽  
Vol 3 (5) ◽  
pp. 379-385 ◽  
Author(s):  
Stefan A. König ◽  
Axel Goldammer ◽  
Hans-Ekkehart Vitzthum
Keyword(s):  
Articular Cartilage ◽  
Articular Surface ◽  
Craniocervical Junction ◽  
Degenerative Changes ◽  
Content Type ◽  
Articular Surfaces ◽  
Anatomical Data ◽  
Grade Ii ◽  
Grade Iii ◽  
Fine Print

>Object. The goal of this project was to measure vertebral dimensions at the craniocervical junction and to investigate degenerative changes in this region and their correlations with the anatomical data. These studies will assist in an understanding of biomechanical conditions in this region, which are clinically relevant in cases of cervicogenic headaches and vertigo. Methods. The authors examined 30 cadaveric specimens obtained from patients ranging in age from 24 to 88 years at death. Measurements of angles of the vertebrae were conducted using an imprint method. Microsections of osseous endplates and articular cartilage were graded according to their degrees of degeneration by using the Petersson classification (0, no sign of degeneration; I, superficial degeneration with several fragmentations; II, deeper degeneration with cartilaginous disintegration and penetrating ulceration; or III, complete cartilaginous degeneration with the appearance of subchondral bone in > 50% of the articular surface). The authors found Grade I changes in 100% of the occiput specimens. In the superior articular cartilage of C-1 no changes (Grade 0) were found in two specimens, whereas 6% of the specimens exhibited Grade II changes and 89% exhibited Grade I changes. In the inferior articular cartilage of C-1, 57% of the specimens displayed Grade I changes, 14% Grade II, and 20% Grade III changes. In the superior articular cartilage of C-2, 62.5% of the specimens displayed Grade I changes and 25% Grade II changes. At the occiput—C1 level the authors found a higher frequency of degeneration at the upper left articular surface of the atlas (Quadrants 1 and 3), and at the C1–2 level they found a higher frequency of degeneration at the upper left and upper right articular surfaces of the axis (Quadrants 2 and 3, respectively). Using the McNemar test, the authors investigated the frequency of affection of single quadrants in a left—right side comparison (lateral reversal). Significant differences were identified for Quadrant 2 of the upper left articular surface of C-2 and Quadrant 3 of the upper right articular surface of C-2. These results correlate with the analysis of single articular surfaces of the axis, but contradict the results for the atlas, in which no significant difference in the left—right side comparison was found. Conclusions. Severe degeneration in the atlantooccipital joints appears to be a rare condition, with no Grade II or III degeneration found in the occipital condyles and 6% Grade I, 89% Grade II, but no Grade III changes in the superior articular cartilage of the atlas. Degeneration of the inferior articular cartilage of C-1 and the superior articular cartilage of C-2 indicates that the atlantoaxial joint faces more intense mechanical exposure, which is increased at the upper joint surfaces.

Muscle basal lamina: a new graft material for peripheral nerve repair

1986 ◽  
Vol 65 (3) ◽  
pp. 354-363 ◽  
Author(s):  
James W. Fawcett ◽  
Roger J. Keynes
Keyword(s):  
Basal Lamina ◽  
Peripheral Nerves ◽  
Nerve Repair ◽  
Graft Material ◽  
Axon Diameter ◽  
Content Type ◽  
Refractory Periods ◽  
Conduction Velocities ◽  
Sciatic Nerves ◽  
Fine Print

✓ The suitability of muscle basal lamina as a graft material for the repair of peripheral nerves was investigated. Grafts were prepared by evacuating the myoplasm from muscles excised from rats and rabbits. This produced a material consisting mainly of basal lamina and connective tissue, with the basal lamina arranged as parallel tubes. Rat- and rabbit-derived graft material in 0.5-cm lengths was sutured into rat sciatic nerves, and 4-cm lengths of rabbit-derived graft material were interposed into rabbit sciatic nerves. For controls, 0.5-cm nerve autografts were grafted into rats and 4-cm autografts into rabbits. After 2 to 3 months, the success of the grafts was assessed functionally, electrophysiologically, and anatomically. By all these criteria the basal lamina grafts were as successful as nerve autografts; essentially the same number of axons of the same size grew through both graft types, animals recovered their limb function equally well, and the nerve conduction velocities and relative refractory periods were the same in both groups of animals. In rats, following both basal lamina and nerve autografts, the number of axons distal to the grafts was approximately the same as that proximal to them, but axon diameter and speed of conduction were significantly less than normal. The authors conclude that muscle basal lamina grafts are as effective as nerve autografts for repairing severed rat or rabbit peripheral nerves, and suggest that grafts prepared in this way may prove to be useful for nerve repair in humans.

Selection of instrumentation and fusion levels for scoliosis: where to start and where to stop

2004 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Keith H. Bridwell
Keyword(s):  
Adult Patient ◽  
Degenerative Changes ◽  
Final Decision ◽  
Adolescent Patient ◽  
Lumbar Curve ◽  
Content Type ◽  
Apical Rotation ◽  
A Minor ◽  
Selection Of ◽  
Fine Print

Object. Although there are several papers in the literature regarding selection of fusion levels in the adolescent patient, fewer articles pertain to this in the adult patient. The author reviewed his experience and the literature and reports on the choice of fusion levels in the adolescent and adult patient. Methods. After a review of available data, the author determined that the proximal and distal extent of the fusion should be based on defining curves as either major or minor in the adolescent patient. It is often possible to exclude minor curves from the fusion. Relative Cobb measurement, apical deviation from the plumb line, and apical rotation are the most useful means of distinguishing a major from a minor curve. Otherwise, the proximal and distal extent of a fusion should be performed in such a way that the proximal and distal vertebrae are both neutral and stable (bisected by the center sacral line) postoperatively. Additional segments may need to be included in the adult patient in whom extensive degenerative changes and subluxations are present. The decision of whether to terminate a long fusion at L-5 or the sacrum in an adult degenerative lumbar curve is complex and many factors have to be considered. Conclusions. Guidelines exist for fusion levels in both adolescent and adult patients. Not all curves require fusion. There are many coronal and sagittal considerations that have to be analyzed when making the final decision.

Spatial pattern of type I collagen expression in injured peripheral nerve

1997 ◽  
Vol 86 (5) ◽  
pp. 866-870 ◽  
Author(s):  
Rahul K. Nath ◽  
Susan E. Mackinnon ◽  
John N. Jensen ◽  
William C. Parks
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Production ◽  
Content Type ◽  
Spatial Expression ◽  
Sciatic Nerves ◽  
Fine Print

✓ The authors studied the spatial expression and regulation of messenger RNA for the a 1 subunit of collagen type I in crushed rat sciatic nerve to provide a basis for future therapeutic manipulation. Sciatic nerves in 20 male or female adult Lewis rats were crushed for 60 seconds; the unharmed contralateral sciatic nerves served as controls. Twenty-one days after injury the experimental animals were killed and their tissue was harvested. The spatial expression of collagen type I was determined by using in situ hybridization techniques. Quantification of fibroblast number and total signal was performed through computerized morphometry. Collagen upregulation was evident in epineurial and perineurial layers, with the epineurium displaying higher activity. The cells responsible for procollagen type I production were fibroblasts. No activity was seen in the endoneurium. Morphometric findings indicated that collagen upregulation in the epineurium and perineurium occurred at both pretranscriptional and posttranslational levels when compared to controls; a paired t-test analysis confirmed statistical significance for all comparisons between injured and control tissues. Epineurial fibroblasts are responsible for the collagen production associated with crushed peripheral nerve injury in the rat. Regulation occurs pretranscriptionally as well as posttranslationally. It is interesting to speculate that the delivery of agents directed against collagen production (such as neutralizing antibodies to growth factors) into epineurial tissues proximate to the time and location of clinical nerve injury might mitigate later deleterious effects of excess collagen production in axonal regeneration.

Reconstruction of the MCA bifurcation after excision of a giant aneurysm

1988 ◽  
Vol 68 (6) ◽  
pp. 974-977 ◽  
Author(s):  
W. Michel Bojanowski ◽  
Robert F. Spetzler ◽  
L. Philip Carter
Keyword(s):  
Doppler Ultrasonography ◽  
Operative Procedure ◽  
Giant Aneurysm ◽  
Left Middle Cerebral Artery ◽  
Content Type ◽  
History Of ◽  
Microsurgical Techniques ◽  
Left Middle ◽  
Good Flow ◽  
Fine Print

✓ A patient with a giant aneurysm of the left middle cerebral artery (MCA) presented with a history of subarachnoid hemorrhage and ischemic symptoms. When the aneurysm was explored, its base was found to be very firm and atherosclerotic. Temporary clips were applied to the MCA, the aneurysm was excised, and the MCA bifurcation was reconstructed using microsurgical techniques. Good flow in the reconstructed MCA trunk was demonstrated by intracranial Doppler ultrasonography. A description of the operative procedure is presented.

Natural history of postoperative aneurysm rests

1987 ◽  
Vol 66 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Isaac Feuerberg ◽  
Christer Lindquist ◽  
Melker Lindqvist ◽  
Ladislau Steiner
Keyword(s):  
Natural History ◽  
Content Type ◽  
Follow Up Studies ◽  
History Of ◽  
Microsurgical Techniques ◽  
Fine Print ◽  
Saccular Aneurysms

✓ In a series of 715 patients operated on by microsurgical techniques for intracranial saccular aneurysms between 1970 and 1980, part of the aneurysmal sac was not obliterated in 28 aneurysms in 27 patients (3.8% of 715 cases). Clinical follow-up evaluation for 8 years (range 4 to 13 years) and angiographic follow-up studies for 6 years (range 2 to 10 years) in these 27 cases revealed that one aneurysm rest increased in size and bled twice, five were spontaneously obliterated, two decreased in size, 13 remained unchanged, and in seven cases no late follow-up angiography was performed. The incidence of rebleeding from an aneurysm rest was 3.7% of the 27 in whom the sac was not obliterated and 0.14% of all 715 patients who were operated on.

RG2 glioma growth in rat cerebellum after subdural implantation

1986 ◽  
Vol 65 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Stanislaw Krajewski ◽  
Jürgen C. W. Kiwit ◽  
Wolfgang Wechsler
Keyword(s):  
Light And Electron Microscopy ◽  
Tumor Model ◽  
Nerve Tissue ◽  
Blue Dye ◽  
Histological Techniques ◽  
Content Type ◽  
Rat Glioma ◽  
Glioma Growth ◽  
Microsurgical Techniques ◽  
Fine Print

✓ The nitrosourea-induced rat glioma clone RG2 was tested for its capacity to form multicellular tumor spheroids (MTS's). Resulting spheroids were investigated by light and electron microscopy with regard to their proliferation patterns and morphological features. Using microsurgical techniques and avoiding mechanical injury of the brain tissue, the authors successfully transplanted avascular MTS's under the dura of the cerebellum, above the vermis, in 43 adult syngeneic Fischer CD rats. The rate of tumor establishment was 93%, and the tumors that were solid and spheroid in shape grew exponentially. Neovascularization could be observed at 3 days after implantation, and invasion of the cerebellum occurred by 3 to 5 days. Neurological deterioration, including ataxia, impairment of walking, and apathy, could be observed after 10 days. The mean survival time was approximately 16 days. The subdural cerebellar tumors were studied by histological techniques, and two morphometric methods were applied to check the growth of implanted spheroids. All tumors were deeply stained with the Evans blue dye-albumin complex, demonstrating disturbance of the blood-brain barrier. The easy accessibility of the cerebellar vermis in rats, the microsurgical implantation of glioma spheroids under the dura avoiding nerve tissue disruption, and the high percentage of reproducible establishment of tumors favor this experimental brain-tumor model. This should be an excellent model for study of experimental therapies.

Spinal cord arteriovenous malformations with significant intramedullary components

1983 ◽  
Vol 59 (3) ◽  
pp. 471-478 ◽  
Author(s):  
Philip Cogen ◽  
Bennett M. Stein
Keyword(s):  
Arteriovenous Malformations ◽  
The Other ◽  
Neurological Deficits ◽  
Content Type ◽  
Postoperative Course ◽  
Microsurgical Techniques ◽  
Spinal Arteriovenous Malformations ◽  
High Degree ◽  
Fine Print

✓ Few neurosurgeons have stressed the occurrence, manifestations, and resectability of intramedullary spinal arteriovenous malformations (AVM's). In six of 17 patients in the authors' series of operable spinal AVM's, the lesions had major intramedullary components. Three of these six patients presented with subarachnoid hemorrhage, and all had catastrophic neurological deficits which gradually improved. The hemorrhages appeared to originate from large venous varices lying adjacent to the intramedullary portion of the AVM. The mechanism explaining the sudden neurological deficit in the other three patients was presumed to be thrombosis within the venous varices associated with their AVM's. The reliability of the various radiographic procedures in identifying the intramedullary components of these AVM's is discussed. These malformations may be removed totally with a high degree of safety using microsurgical techniques. The postoperative course in this series of patients was gratifying in terms of improvement of neurological deficits. Postoperative angiography was not performed on all of these patients. However, the follow-up period averaged 5 years.

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