摘要:

THIS STUDY PRESENTS six patients with hypothalamic hamartomas diagnosed on the basis of magnetic resonance imaging. Histological confirmation was performed in three patients who underwent surgery. Immunohistological assays were used to determine the neurosecretory pattern. Four patients presented with epilepsy, including gelastic seizures. Other symptoms included behavioral abnormalities in four patients and precocious puberty and visual impairment in two patients. One patient presented associated developmental defects. Good results without morbidity were achieved with surgical resectioning in two patients with large hamartomas associated with behavioral abnormalities and gelastic epilepsy that was unresponsive to conventional medical treatment and in one patient with visual impairment. We propose a classification of the hypothalamic hamartomas based on topographical and clinical data obtained from 36 selected cases in the literature and six of our own cases. This classification should help to classify the various treatment methods and the surgical risks into four subgroups (Types Ia, Ib, IIa, and IIb). We conclude that the surgical approach is a realistic alternative in certain cases, including large and broad-based Type IIb hamartomas associated with gelastic epilepsy and behavioral disorders.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

IN A RETROSPECTIVE study of 82 cases of oligodendroglioma, the influences of tumor size, site, and grade, the age of the patient, the extent of surgical excision, and the effect of additional radiation therapy on the clinical course, as well as their dependencies, were investigated. Tumor grade and tumor site significantly affected the survival rates of the patients. When tumor site was kept constant by distinguishing between frontal and nonfrontal localized oligodendrogliomas, the grading system still showed discriminating power. Conversely, when controlled for grade, the frontal site appeared to be favorable for prognosis. Age was only faintly correlated with survival, with younger patients tending to survive longer. This was compatible with the finding that, in younger patients, more frontal localized tumors were found and that older patients had oligodendrogliomas with higher grades. Tumor volumes did not correlate with survival. No correlation between tumor volume and tumor grade was found. Patients who had undergone a decompression tended toward longer survival, although this trend did not reach significance. No beneficial effect of radiation therapy on the survival rate was demonstrable.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

MUTATIONS IN THE p53 gene, which codes for a cell division regulatory protein, have been identified in approximately one-third of adult astrocytomas. We evaluated 35 astrocytic tumors (17 pilocytic, 4 diffuse low grade, 12 anaplastic, and 2 glioblastoma) in pediatric patients for p53 mutations, using polymerase chain reaction-single-stranded conformation polymorphism analysis as a screening technique. Additionally, those tumors identified with homozygosity in the area of the p53 gene on chromosome 17 by Southern blotting were sequenced to look for p53 mutations. No tumors were identified with polymerase chain reaction-single-stranded conformation polymorphism analysis shifts indicative of mutations in the p53 gene. Five of 21 tumors were homozygous in the region of the p53 gene on chromosome 17; no mutations in exons 5 to 8 were found in any of these tumors. The frequency of p53 mutation in pediatric astrocytomas is significantly less than the frequency for adult tumors, regardless of tumor grade. Furthermore, the frequency of p53 mutations in high-grade astrocytomas is significantly lower in pediatric tumors than in adult tumors. These results suggest that p53 is not important in the oncogenesis of pediatric astrocytomas. Oncogenesis in pediatric astrocytomas may occur by different mechanisms than those of similar tumors in adults.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A RETROSPECTIVE STUDY of subdural empyema and epidural abscess spanning 11 years and encompassing 41 patients was performed, demonstrating that the clinical characteristics of intracranial suppuration have changed over time. Sinusitis and otitis media, previously the predominant etiologies, were predisposing factors in only 29% of patients. A prior craniotomy had been performed in 66% of cases and was the most common risk factor for abscess development. The postoperative patients were subjected to detailed analysis. Patients who had undergone a prior craniotomy were notable for the following features: older age, lack of fever, evidence of wound infection, frequent false-negative computed tomographic scans, and a high percentage of Gram negative aerobic organisms or skin flora as pathogens. The population at highest risk for abscess development ranged from 50 to 60 years old, older than in previous series. Older age and an advanced degree of encephalopathy were indicative of a poor prognosis. Patients with subdural empyema had a worse prognosis as well. Hyponatremia was a frequent complicating factor. A much greater percentage of Gram-negative aerobic bacteria were isolated than in previous studies. Computed tomographic scans, half of which were performed with intravenous contrast material, were nondiagnostic in 30% of patients. The mortality rate was 18.5%, and delay in treatment correlated with increased risk of poor outcome. All patients were treated with a craniotomy. Repeated operations were required in three patients and were associated with the development of intraparenchymal abscess.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

HYPONATREMIA HAS BEEN reported in up to one third of patients with intracranial disease and has frequently been associated with tuberculous meningitis, often complicated by hydrocephalus. The lowered plasma sodium levels were previously attributed to the syndrome of inappropriate secretion of antidiuretic hormone. A controlled prospective study of 24 patients with tuberculous meningitis and hydrocephalus was carried out. Analyses of serum electrolytes and cerebrospinal fluid were performed. Plasma and cerebrospinal fluid levels of atrial natriuretic peptide (ANP) and antidiuretic hormone (ADH) were measured by radioimmunoassay. Fifteen patients were found to be hyponatremic (plasma sodium < 130 mmol/L) and ANP levels of 12 to 1,488 pg/ml were present (median, 26 pg/ml). The remaining 9 patients had normal plasma sodium values between 130 and 145 mmol/L, and in these, plasma ANP values varied between 12 and 21.7 pg/ml (median, 12 pg/ml). The difference between these two groups was not statistically significant. (Control values from patients undergoing myelography were established to range between 12 and 40 pg/ml; median, 14.4 pg/ml.) ANP levels were undetectable in the cerebrospinal fluid in all. Plasma ADH levels in the hyponatremic group were between 7 and 159 pg/ml (median, 40 pg/ml). In the normonatremic group, plasma ADH levels of 25 to 250 pg/ml (median, 29 pg/ml) were obtained. (The controls ranged between 3.6 and 35 pg/ml; median, 10.4 pg/ml). In the hyponatremic group, there was a moderate negative correlation (r= −0.683) between plasma ANP and plasma sodium (P= 0.02). No correlation between plasma ADH and plasma sodium was found (r= −0.168;P= 0.62). It therefore appears that plasma ANP accounted for 65% of the variation in plasma sodium (P= 0.0085), while ADH accounted for only 3% (P= 0.489). These findings suggest that elevations in plasma ANP account for the major proportion of the hyponatremic states in tuberculous meningitis with hydrocephalus, while ADH, initially thought to be important, seems to play a negligible role. A more accurate and useful description of the hyponatremic state in tuberculous meningitis would be “hyponatremic natriuretic syndrome.”

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

EPIDURAL CYSTS, EITHER synovial or ganglion, are an unusual cause of epidural compressive syndromes. We report a series of 26 patients with cysts, including 1 cervical, 2 thoracic, and 23 lumbar. Complaints at the time of admission and findings were similar to those associated with other epidural lesions at the same locations. The surgical technique is similar to that for other spinal lesions, with a wide exposure to enable a clear view of the cyst and surrounding structures, and is governed by imaging studies. Patients with cervical and thoracic lumbar cysts were free of symptoms and signs postoperatively. Of the 23 patients with lumbar cysts, 15 were free of symptoms after an operation, 7 had symptomatic improvement but had some pain and neurological findings, and 1 patient had no improvement. Computed tomography and magnetic resonance imaging permit accurate preoperative evaluation.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

PROTON MAGNETIC RESONANCE spectroscopic imaging (1H-MRSI) and positron emission tomography with the tracer L-[1-11C]tyrosine (11C-TYR) were used to localize gliomas for biopsy or resection. This is especially helpful in cases of low-grade gliomas, if these lesions are not visualized by contrast-enhanced computed tomographic and magnetic resonance imaging scans. The clues to improved localization are provided by changes in tissue metabolite contents, such as elevation of phosphocholine, indicating cellular proliferation; decrease ofN-acetylaspartate, denoting loss of neurons (as these are replaced by tumor cells); and elevation of lactate, pointing to the prevalence of glycolysis, as observed in many tumors. These data on tissue metabolite content have been obtained in vivo in the patient by proton magnetic resonance spectroscopy; metabolite maps derived from these data then visualize the distribution of the various metabolites over the section of the brain under investigation. Alternatively, localization of a tumor may be achieved by means of positron emission tomography depicting the pattern of uptake of the amino acid tracer11C-TYR, as it tends to be incorporated in the process of cellular proliferation and protein biosynthesis. Five cases are presented as examples.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE RETROSIGMOID TRANSMEATAL technique remains the approach of choice for hearing preservation during the removal of acoustic neuromas that protrude from the porus acusticus. However, encroachment into the bony labyrinth in an effort to remove the tumor in the lateral end of the internal auditory canal (IAC) continues to compromise hearing in certain cases. The limits in the safe removal of the posterior wall of the IAC are not generally agreed on. To address this problem, we have performed a morphometric analysis of 32 fixed cadaveric temporal bones by microsurgical dissection and measurement with fine-cut bone window computed tomographic (CT) scans. The morphometric relationships of identifiable surface landmarks were first determined. Fine cut bone window CT scans were next performed on each bone and the distances between the fundus, the vestibule, and the common crus (CC) with the internal auditory meatus (IAM) were determined. Additionally, the thickness of the bone overlying the posterior semicircular canal at the CC was measured. From a retrosigmoid trajectory, employing a 4-cm craniotomy, the posterior wall of the IAC was removed with a high-speed drill, limiting removal to the distance from the vestibule to the IAM, as determined by CT measurement. Preservation of the integrity of deep structures was confirmed by inspection. The length of the actual IAC unroofed was measured and was compared with the IAC length, from IAM to fundus, measured by CT. The average canal length by CT measured 10.0 mm ± 1.8 (range, 6.6–14.0). The length of the canal uncovered averaged 5.9 mm ± 1.4 (4.0–8.5). The vestibule, CC, and posterior semicircular canal were then uncovered, and measurements were taken to verify those determined by CT. The average distances from the IAM to the vestibule and CC closely correlated with those determined by CT and were 9.52 mm ± 1.93 (6.5–13.5) and 10.43 mm ± 2.13 (7.0–14.0), respectively. The average greatest thickness of bone overlying the posterior semicircular canal was 3.64 mm ± 1.43 (1.5–6.5). Analysis of all morphometric data failed to reveal a reliable correlate between surface landmark morphometry and the structures of the inner ear. From this study, we conclude the following: 1) there is significant variability in the morphometry of the adult temporal bone; 2) surface morphometric relationships may be generally unreliable as a guide to internal temporal bone anatomical relationships; 3) it is not safe in most cases to broadly apply a generalized guideline measurement for the unroofing of the posterior IAC without a high risk of violating the bony labyrinth or vestibule; 4) from a retrosigmoid trajectory, the extent of IAC unroofed is less than the measured length of the canal because of the angle of approach; 5) the length of the IAC that may be uncovered safely is, in general, proportional to the angle of approach; and 6) preoperative imaging with fine-cut bone window CT will provide a reliable and valuable adjunct to maximize the exposure of the IAC contents, while helping to minimize morbidity.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE EXTRADURAL MIDDLE fossa transpetrosal approach has been used to access lesions of the petroclival and posterior cavernous sinus regions by several neurosurgical groups, including our own. This is a technically demanding approach that provides a relatively wide extradural corridor interposed between the 5th cranial nerve and the cranial nerve VII-VIII complex, which minimizes brain retraction. We performed a microanatomical study to determine the limits of this exposure and in particular how the removal of the petrous bone could be maximized through this approach. Dissection of 15 fixed human cadaveric heads and 8 isolated temporal bones was performed to yield 38 sides studied. We identified a rhomboid-shaped construct of middle fossa landmarks that serve as a guide to maximally removing the petrous apex. The points defining this construct are as follows: 1) the junction of the greater superficial petrosal nerve and the trigeminal nerve; 2) the lateral edge of the porus trigeminus; 3) the intersection of the petrous ridge and arcuate eminence; and 4) the intersection of the lines extended along the axes of the greater superficial petrosal nerve and arcuate eminence. A morphometric analysis determined the average lengths of the respective sides of the complex to be 13.2 mm ± 2.6 × 22.2 mm ± 2.8 × 16.4 mm ± 3.4 × 16.6 mm ± 1.5 (beginning at “1” and proceeding sequentially), with an approximate area of the construct equal to 2.9 square centimeters. Maximal bone removal was found to extend inferiorly beyond the inferior petrosal sinus to the clivus, posteriorly to unroof the internal auditory canal completely, anteriorly under the trigeminal ganglion to include the petrous apex, and laterally to the geniculate ganglion and carotid artery. A simple geometric construct was also devised that proposes to assist in locating the cochlea.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

TWENTY-EIGHT ABDUCENT NERVES were examined after injecting india ink and gelatin into the vertebrobasilar arterial system. All the abducent nerves were found to be crossed and/or penetrated by the surrounding vessels. The ventral surface of the nerves was crossed by the anterior inferior cerebellar artery (AICA) (75.0%), the posterior inferior cerebellar artery (17.85%), the common trunk of the AICA and posterior inferior cerebellar artery (7.14%), the internal auditory artery (14.28%), the anterolateral artery (46.43%), the pontomedullary artery (92.86%), and the corresponding veins (46.43%). The dorsal surface of the cisternal segment was crossed by the AICA (35.71%), the inferolateral pontine artery (10.71%), the anterolateral artery (82.14%), and the certain veins (46.43%). Sixty-four percent of the cisternal segments were penetrated by one or more of the following vessels: the AICA (25.0%), the anterolateral artery (17.86%), the pontomedullary artery (3.57%), and/or by the corresponding veins (42.86%). The majority of the cisternal segments of the abducent nerves were supplied by the anterolateral arteries (85.71%), and only some of them by the AICA (14.29%) or the pontomedullary artery (7.14%). The authors discuss the possible clinical significance of the anatomical data.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID