摘要:

&NA;Intraventricular and intra‐axial lesions can be reached through a transsulcal approach, avoiding the more extensive cerebral tissue damage that may result from a conventional cortical incision. The sulci of five cadaver brains fixed in formalin solution were dissected using the operating microscope. The brains were photographed for surface mapping and x‐rays to demonstrate underlying ventricular relationships were taken. The brains were then coronally sectioned to characterize anatomical relationships between sulci and deep brain structures. Three important sulci were identified and thoroughly characterized with respect to surface relationships, average depth, and underlying structures that can be readily approached. Surgical application of these findings is discussed. (Neurosurgery24:651‐654, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The authors report on a series of 53 bedridden patients suffering from harmful spasticity in one (6) or both (47) lower limbs, who were treated with microsurgical DREZ‐otomy. Surgery was performed to treat fixed abnormal postures in flexion in 49 patients and hyperextension in 3, and, additionally, to treat pain in 37 patients. Microsurgical DREZ‐otomy was introduced in 1972, on the basis of anatomical studies of the human dorsal root entry zone (DREZ) showing a topographical segregation of the afferent fibers according to their size and functional destinations. It consists of a 2 mm deep microsurgical lesion directed at a 45° angle in the posterolateral sulcus and penetrating the dorsal root entry zone in its ventrolateral aspect, at the level of all the rootlets considered involved in spasticity (and pain). It destroys mainly the lateral (nociceptive) and central (myotatic) afferent fibers as well as the facilitatory medial part of the Lissauer tract, while sparing most of the medial (lemniscal) fibers, the suppressor lateral part of the Lissauer tract, and more or less of the dorsal horn (DH). The postoperative results were evaluated after a mean follow‐up period of 3 years and 4 months. Both spasticity and spasms were significantly decreased or suppressed in 75% and 88.2% of the patients, respectively. When present, pain was relieved without abolition of sensation in 91.6%. These benefits—combined with complementary orthopedic surgery in 23 patients—resulted in either disappearance or marked reduction of the abnormal postures in 85.3% of the patients and of articular limitations in 96.8%. Mid‐to‐severe complications occurred in 25 patients and precipitated or were responsible for death in 5. This is explained by the fact that the general and neurological conditions of most of the patients—especially those affected by multiple sclerosis—were precarious. MDT has, however, enabled a majority of these severely disabled patients to sit and lie comfortably, and has allowed them to reach a significantly improved quality of life. (Neurosurgery24:655‐670, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The cerebral effects of alterations in plasma osmolality (Osm) and colloid oncotic pressure (COP) were examined in normocarbic, normothermic, pentobarbital‐anesthetized rabbits that had been subjected to cryogenic brain injury. Monitored variables in all animals included mean arterial, right atrial, and intracranial pressures (MAP, CVP, and ICP), electroencephalographic (EEG) recordings, and cerebral blood flow (CBF). When surgical preparation was complete, a left parietal lesion was produced with liquid nitrogen. Group 1 (control, n = 8) animals subsequently received only maintenance fluids [lactated Ringer's solution (LR)]. One hour after injury, 3 other groups of animals underwent 45 minutes of plasmapheresis, carried out by arterial phlebotomy (packed red cells returned), with separated plasma being replaced by one of three fluids given in amounts sufficient to maintain MAP and CVP at baseline values. The three fluids were 1) 6% hetastarch in hypo‐osmotic LR [Group 2 (Hypo‐Osm), n = 6; COP = 21 mm Hg, Osm = 130 mOsm/kg]; 2) iso‐osmotic LR [Group 3 (Hypo‐COP), n = 8; COP = 0; Osm = 305]; and 3) 6% hetastarch in iso‐osmotic LR [Group 4 (Iso‐Osm/COP), n = 8; COP = 21, Osm = 310]. The animals were killed by exsanguination 25 minutes after completion of plasmapheresis. The brain was removed, the hemispheres separated, weighed, and sliced, and the specific gravities (SpGr) of the regional tissue determined. There were no differences in MAP, CVP, regional CBF, or EEG activity among the groups. In Group 2, osmolality decreased by 12.7 ± 2.9 mOsm/kg (mean ± SD, COP unchanged), while ICP increased to 22 ± 6 mm Hg (P< 0.001 vs. Groups 1, 3, and 4) and CBF decreased to 73% of that recorded prior to plasmapheresis. In Group 3, COP was reduced by 10.8 ± 2.2 mm Hg (Osm unchanged), while both COP and osmolality were unchanged in Group 4. ICP increased in these groups to 9 ± 3 and 13 ± 4 mm Hg, respectively, compared with 14 ± 9 in Group 1. The lesion itself caused decreases in regional SpGr in all animals (as compared with the contralateral hemispheres). The only significant fluid‐related difference, however, was associated with a reduction in osmolality—and only in tissues remote from the injury. Changes in COP had no detectable effects. These results indicate that in the acute phase of brain injury, reductions in COP do not play an important role in brain edema formation, and that changes in osmolality alter water content only in relatively normal brain regions. (Neurosurgery24:671‐678, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;This study evaluates the effect of superoxide dismutase, a scavenger of oxygen free radicals, on peritumoral and cold injury edema. Vasogenic brain edema was produced in 39 cats by a standardized cortical freezing lesion. Peritumoral edema was produced by the transplantation of VX2 carcinoma cells into the brain of New Zealand White rabbits. Detection of superoxide radicals was studied by topical application of nitroblue tetrazolium to the cortical injury and by incubation of the VX2 carcinoma cells. The aniamls were treated with free superoxide dismutase (SOD) and polyethylene glycol superoxide dismutase (PEG‐SOD). The following groups were studied: 1) control, 2) untreated tumor group, 3) tumor group treated with PEG‐SOD, 4) a group treated with PEG‐SOD before injury, and 5) a group treated with free SOD after injury. Brain edema was evaluated by measurement of specific gravity and planimetry study of the spread of Evans blue dye. Preliminary data indicate that superoxide radicals are present in the brain after cold injury and in the cytoplasm and nucleus of VX2 carcinoma cells. Free SOD and PEG‐SOD had no beneficial effect upon the vasogenic brain edema produced in either model. It is concluded that intracellular uptake of SOD may be one of the factors necessary for an effect upon either form of edema. (Neurosurgery24:679‐685, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Eighty‐five “well‐differentiated” astrocytomas in adults (age, ≥18 years), operated on between 1950 and 1982, were retrospectively reviewed. The pilocytic variant was not included. Twenty‐four clinical and 8 histological factors were analyzed to investigate their importance in predicting length of survival. Multivariate analysis showed that the following variables were correlated with survival time (P < 0.01): extent of surgical removal, altered consciousness during preoperative examination, focal deficit as presenting symptom, performance status (Karnofsky rating) after surgery, and vessel size in the surgical specimen. Total removal of the tumor was related to a higher 5‐year survival rate (51%) than subtotal removal (23.5%), and none of the patients with partial removal survived more than 5 years. Postoperative radiotherapy (40‐55 Gy) improved only the 1‐ and 3‐year survival rates. Based on the significant factors provided by multivariate analysis, a score was developed to detect subgroups with different prognoses. Median survival time ranged from 383 days for patients with a score ≥2.5 to 1,533 days for those with a score <0.5; no patient with a score ≥1.5 survived more than 10 years. The percentage of recurring astrocytomas that showed anaplastic areas in the second biopsy specimen was 79%. Total surgical removal is the most important factor in the management of well‐differentiated astrocytomas, whereas the efficacy of postoperative radiotherapy still needs to be confirmed by prospective and randomized studies. The rationale for treating incompletely resected astrocytomas with radiation therapy could lie in the high incidence of malignant transformation. (Neurosurgery24:686‐692, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;A retrospective review of colloid cysts diagnosed from 1974 to 1986 emphasizes the presenting symptoms of these lesions, their surgical management, and the contribution of modern imaging techniques to their diagnosis and therapy. In this 12‐year period, 84 patients (45 men and 39 women) had a colloid cyst diagnosed. The patients' mean age was 46 years (range, 7‐82 years). Surgery was performed in 55 patients, 7 of whom had undergone prior surgery elsewhere. The surgical approaches used were transfrontal‐transventricular, transcallosal, computer‐assisted stereotactic aspiration and resection by stereotactic craniotomy, and shunting of cerebrospinal fluid without removal of the lesion. There was no operative mortality, but complications occurred in 15 patients (27%). Preoperative imaging showed hydrocephalus in 93% of the patients: severe in 43%, moderate in 36%, and mild in 14%. In the surgically treated group, the most common presenting symptoms were headache, change in mental status, ataxia, nausea and vomiting, visual disturbance, emotional lability/inappropriate affect, depersonalization, and hypersomnolence. Twenty‐four patients for whom surgery was not recommended are being followed up closely. Most of these patients had normal ventricles. The symptoms in this group included headache, anxiety/nervousness, ataxia, memory impairment, visual disturbance, and seizures. Five autopsy cases of patients with colloid cysts were available during this period and were reviewed. Direct removal of colloid cysts can be accomplished with low morbidity and mortality, avoiding the frequent revisions and complications related to shunt procedures. There is a subgroup of colloid cysts that can be operated upon electively or followed up closely with serial imaging studies. (Neurosurgery24:693‐700, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;A CD 344 rat glioma model currently used to investigate boron neutron capture therapy (BNCT) was used to demonstrate an increased survival rate after thermal neutron irradiation enhanced by administration of10B‐enriched polyhedral borane, Na2B12H11SH. To investigate the possible effects of BNCT on normal and tumor microvasculature, we subjected animals to sublethal neutron irradiation with and without intravenous injection of 50 mg/kg of enriched10B and performed histological and ultrastructural analyses. In the rats that did not undergo tumor transplantation, minimal detectable morphological changes in the microvasculature of the central nervous system were observed after treatment, both in the immediate posttreatment phase and at 10 months. Light microscopy of cerebral cortex and caudate nucleus showed normal cytoarchitecture with no evidence of vessel occlusion, hyalinization, thickening, or reactive gliosis. Electron microscopy demonstrated that the junctional complexes of the endothelial cells, the basal lamina, and the perivascular glia were comparable in both treated and control animals. In those animals examined at 18 months, pathological membrane‐bound clusters of electron‐dense vesicles were seen in pericytes. In the rats implanted with gliomas, vascular proliferation with evidence of breakdown of the blood‐brain barrier and vasogenic edema occurred. In the irradiated animals, we noted increased peritumoral edema 3 days after treatment. At seven days, both increased peritumoral edema and necrosis were noted in the rats treated with BNCT. These observations show that the normal microvasculature of the central nervous system tolerates BNCT at the treatment parameters used in our experimental model; the progressive edema and necrosis found in the peritumoral region after BNCT indicate a pathological endothelial response. (Neurosurgery24:701‐708, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;We present the results of monitoring descending pathways with motor evoked potentials (MEP) in 50 patients during neurosurgical operations on the spinal cord. The electromyographic responses of the anterior tibial muscles were recorded. In addition, in 24 patients responses of the thenar muscles after transcranial electrical stimulation of the motor cortex were recorded. Usually, the averages of 5 to 15 signals were evaluated. Although potentials were obtained preoperatively in all 50 patients, during neuroleptanesthesia intraoperative recording from the anterior tibial muscles was possible in 43 patients (86%) and from the thenar muscles in 21 patients (87.5%). Amplitudes were superior to latencies as evaluation criteria for intraoperative changes in potentials. On the basis of acceptable changes in amplitudes of up to 50% at the end of the operation, 16 recordings from the thenar muscles (76.2%) and 35 from the anterior tibial muscles (81.4%) correlated correctly with the postoperative neurological status; there were false positive results in 5 (23.8%) and 8 (18.6%) patients, respectively. We did not observe false negative findings. Postoperative neurological complications coincided in every case with permanent reduction in amplitudes of more than 50% of the base lines or with intraoperative loss of potentials as observed in 3 and 1 patient, respectively. MEP monitoring during neurosurgical operations on the spinal cord is a sensitive method for early detection of impending neurological complications. Major problems are the influence of anesthesia and the definition of acceptable limits for changes in amplitudes. (Neurosurgery24:709‐712, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Evidence has accumulated that indicates that laminectomy with or without radiotherapy is not necessarily the best mode of treatment for all cases of spinal cord compression of malignant pathogenesis. Success is limited, and there is a high risk of adverse neurological developments, particularly where there is anterior vertebral collapse. A prospective series of 26 consecutive patients with neurological complications of neoplastic extradural cord compression is described. Anterior decompression followed by stabilization in a single stage procedure was selected as the most appropriate method of treatment for all 26 patients. Various techniques were used in the replacement of the excised vertebral body, including the use of two types of prosthesis created specifically for the purpose. Of the patients who were not ambulatory at the time of surgery, 62% became so postoperatively; 71% of those with intractable pain were pain free after surgery. The postoperative mortality rate was 30%, which reflected the poor condition of the patients; in light of this, the criteria for operative selection are reviewed. Neurological deterioration did not occur in any patient. The method is recommended, for selected patients, for the management of cord compression caused by collapse of the vertebral body. The patient's prospects of restored ability to walk after a single‐stage operation are good, and the risk of adverse neurological effects is negligible. (Neurosurgery24:713‐717, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;In three cases of lumbar disc herniation, autologous fat grafts were inserted over the dura mater and the exposed nerve roots during surgery with the aim of preventing postoperative epidural fibrosis. A second operation had to be performed in two of these cases as a result of the radiographic appearance of excessive scar formation in the epidural and adjacent regions of the nerve root giving rise to symptoms. In the third patient, myelographic studies revealed the development of this type of hypertrophic scarring; however, the patient refused a further operation. The hypertrophic epidural scarring occurred in these three cases despite the presence of autologous fat grafts. Histopathological examination of the fat removed from the two patients who were operated on a second time showed a fibrotic infiltration into the fat graft. (Neurosurgery24:718‐721, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID