Posterior fossa tumors in children--indications for ventricular drainage and for V-P shunting

A clinical analysis of 95 patients with posterior fossa tumors treated in the Department of Neurosurgery of the Medical University in Gdansk over a period of 16 years (1979-1995) is presented. The following preoperative factors were studied: localization, size and suspected type of tumor, size of the ventricular system, and presence or absence of the "halo" symptom. The indications for ventricular drainage (Fisher) versus V-P shunting as a preliminary treatment are discussed. Finally, the advantages of each of these procedures are emphasized.     

Core neurocognitive functions in children treated for posterior fossa tumors.

Identifying cognitive deficits associated with pediatric brain tumors and their treatment is important in delineating the mechanisms of intellectual decline often associated with these diseases. The authors evaluated sustained attention, information processing speed, working memory, and IQ in 64 patients with posterior fossa tumors, including those treated with either: (a) surgery and cranial radiation (n = 32), and (b) surgery without radiation (n = 32). Ten patients treated for non-CNS solid tumors were included as a comparison group. The authors also examined the impact of relevant demographic and medical variables on neurocognitive outcome. The authors found that neither age at, nor time since, diagnosis predicted cognitive outcome in this sample. Further, sustained attention and working memory were largely intact and there were no differences between groups. Patients treated with cranial radiation demonstrated lowered short-form IQ and slow information processing speed: Patients treated with cranial radiation and who experienced postsurgical complications demonstrated the poorest performance. The authors consider information processing speed to be an excellent candidate mechanism in understanding the impact of cranial radiation on intellectual outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posterior fossa meningiomas: surgical experience in 52 cases

The ability to discriminate between galactose and N- acetylgalactosamine, observed in some lectins, is crucial for their biological activity as well as their usefulness as tools in biology and medicine. However, the molecular basis of differential binding of lectins to these two sugars is poorly understood. Peanut agglutinin (PNA) is one of the few galactose-specific legume lectins which does not bind N- acetylgalactosamine at all and is, therefore, ideal for the study of the basis of specificity towards C-2 substituted derivatives of galactopyranosides. Examination of the three-dimensional structure of PNA in complex with lactose revealed the presence of both a longer loop and bulkier residues in the region surrounding the C-2 hydroxyl of the galactopyranoside ring, which can sterically prevent the accommodation of a bulky substituent in this position. One such residue, is a glutamic acid at position 129 which protrudes into the binding site and perhaps directly obstructs any substitution at the C-2 position. Two mutants in bacterially expressed PNA were therefore constructed. These were E129D and E129A, in which Glu129 was replaced by Asp and Ala, respectively. The specificity of the mutants for galactose, galactosamine, and N- acetylgalactosamine was examined through observing the inhibition of hemagglutination and binding of the lectin to immobilized asialofetuin. The results showed that the affinity of E129A and E129D for C-2-substituted derivatives of the galactose varies. The mutant E129D showed significant binding towards N- acetylgalactosamine, suggesting that the residue Glu 129 is crucial in imparting exclusive galactose-specificity upon PNA. This study not only attempts to provide an explanation for the inability of PNA to accommodate C-2-substituted derivatives at its primary subsite, but also seeks to present a basis for engineering lectins with altered specificities.     

Posterior fossa decompression without duraplasty in infants and young children for treatment of Chiari malformation and achondroplasia

Some children with Chiari malformation and achondroplasia require posterior fossa decompression that typically includes expansion of the dural tube with duraplasty. Infants and young children, however, may have a more distensible dura mater than do older patients. Furthermore, the structures that compress the hindbrain of young patients may be the bone and abnormally thickened atlantooccipital membrane, i.e., dural band, rather than the dura mater. We have treated 7 children who had Chiari malformation or achondroplasia with posterior fossa decompression without duraplasty. All children were symptomatic; 3 had Chiari-I malformations, 2 Chiari-II malformations, and 2 achondroplasia. The age range was 3 months to 2.5 years (mean 15.1 months). The exent of tonsillar herniation and other hindbrain anomalies was assessed on preoperative magnetic resonance imaging. The infants with Chiari-II malformations underwent cervical laminectomies, whereas the other young children with Chiari-I malformations or achondroplasia underwent suboccipital craniectomy as well as cervical laminectomy. In Chiari malformation, the dural band was divided; in achondroplasia, there was no identifiable dural band. Following bony decompression and division of the identifiable dural band, immediate expansion of the stenotic region with visible cerebrospinal fluid space posterior to the neural elements could be ascertained by intraoperative ultrasonography. During a follow-up period ranging from 4.5 months to 4 years (mean 22 months), all patients made improvements in their symptoms, 3 having complete resolution of their symptoms. This preliminary experience indicates that in children 2 years of age or younger, posterior fossa bony decompression without duraplasty can be effective treatment for Chiari malformations or achondroplasia.     

Posterior fossa epidural hematomas: a review and synthesis

The authors report three patients with posterior fossa epidural hematomas and analyze 80 additional cases in the accessible literature. They occur in the younger age groups with a clear male predominance (3.6 to 1). The loss of consciousness at the time of impact and just before surgical intervention have both proved to be factors indicating a poor prognosis. The clinical symptoms and signs were classified in three general types: increased intracranial pressure, brainstem dysfunction, and cerebellar disturbances. A fracture of the occipital bone was seen in 84.2% of the patients. The source of bleeding often remained undetermined, although a tear of the dural sinuses was a most frequent finding. An associated intracranial lesion was found in 39.7% of the cases, this being another factor indicating a poor prognosis. The overall mortality was 26.5%, while the surgical mortality was only 11.5%. Excellent results were achieved in 65% of the cases.     

Torticollis secondary to posterior fossa tumors

Torticollis in childhood may be a sign of many disorders. Five cases, with torticollis as the initial sign of a posterior fossa tumor, are presented. The diagnosis and treatment of the tumor was considerably delayed in all patients because posterior fossa tumor was not considered in the initial differential diagnosis. In two patients, operative procedures on the sternocleidomastoid muscle were performed before discovering the underlying causative tumors. Four of the five patients also had other associated symptoms such as headache, nausea, and vomiting. It is stressed that in acquired torticollis, posterior fossa tumor be considered in the differential diagnosis.     

Posterior chamber intraocular lens use in children

PURPOSE: The authors report on the efficacy of intraocular lens implantation during pediatric cataract surgery and the results of a consecutive series of intraocular lens implantation in children. METHODS: Twenty-one children underwent implantation of intraocular lenses in 23 eyes. Twenty-one surgeries were primary implantation immediately following anterior lensectomy. Two surgeries were secondary implantations. Primary posterior capsulectomy was performed in 18 of 21 primary implantations. All but two eyes underwent a primary anterior vitrectomy. Topical prednisolone acetate was administered in all cases. Oral prednisone was administered in 17 of 23 cases. Pre- and postoperative visual acuity, cycloplegic refraction, and postoperative complications related to inflammation such as intraocular lens (IOL) capture, IOL decentration, and posterior capsule opacification were examined. RESULTS: Eighteen of 23 eyes have achieved a visual acuity of 20/40 or better. None of the cases in which oral prednisone was used developed complications related to postoperative inflammation. One of the six cases (17%) in which oral prednisone was not used developed such complications. CONCLUSION: Intracular lens implantation accompanied by primary posterior capsulectomy, anterior vitrectomy, and management of postoperative inflammation appears to provide appropriate and safe optical rehabilitation in children.     

Posterior cranial fossa surgery in 454 children. Comparison of results obtained in pre-CT and CT era and after various types of management of dura mater

At the Department of Neurosurgery, Hradec Kralové, 454 children (aged under 18 years) were operated on for posterior cranial fossa lesions in a period of 49 years (1948-1996). The majority (402) had tumours: cerebellar astrocytomas 149 (37.1%), medulloblastomas 139 (34.6%), brain stem gliomas 46 (11.4%), ependymomas 28 (7.0%), and others 40 (9.9%). Postoperative mortality was compared for the pre-CT era (1948-1977) and the CT era (1978-1996): astrocytomas (8.6%:4.7%), medulloblastomas (14.9%:2.9%), brain stem gliomas (21.7%:19.0%), ependymomas (18.2%:6.3%), and others (40.0%:7.4%). The initially high mortality was due to insufficient intracranial decompression, brain oedema and disturbances of cerebrospinal fluid circulation. Obstructive hydrocephalus was treated in 53 children with tumours and 25 with aqueduct stenoses, by Torkildsen's drainage in 5.5%, and/or by catheterisation of aqueduct in 12.3%. The main postoperative complications of medial posterior fossa surgery in 429 children operated on were: pseudomeningocele (12.3%), active hydrocephalus (6.2%) and CSF leakage (4.6%). Only 8.2% had shunts placed for these complications. We presume that this low percentage of shunts used results from a frequent use of duraplasties and drains installed at the primary operation. The dura mater was initially (1948-1954) left open (50 cases), and later (1955-1958) also sutured (37 cases), and from 1958, onward, and especially from 1961, reconstructed by a medial approach by means of various grafts (377 cases). In all, duraplasty was performed in 81.6% of cases. The grafts used for dura mater reconstruction were prepared from autogeneic (1.6%), allogeneic (72.3%), xenogeneic (24.8%), or synthetic (1.3%) material. They were successful in 99.2% of cases (all materials). Our own suture technique for posterior fossa duraplasty is presented.     

Posterior fossa decompression for Chiari I deformity, including resection of the cerebellar tonsils

This is an analysis of 19 consecutive cases of symptomatic patients with Chiari I deformities, undertaken to evaluate the long-term effect of posterior fossa decompression and duraplasty, assessed by postoperative imaging. Sixteen of the patients had syringomyelia and three had foramen magnum syndromes without a syrinx. Eighteen patients underwent posterior fossa craniectomy, subpial resection of the cerebellar tonsils, and duraplasty. Four patients were 16 years of age or younger. One of the children with syringomyelia had a posterior fossa decompression without resection of the tonsils. In the 15 patients with syringomyelia whose surgery included resection of the tonsils, the syrinx was reduced or resolved in 14. The patient whose syrinx did not change was a child with a lumbosacral lipoma. Three patients had syndromes of the foramen magnum without a syrinx, and of these only a patient with prior chemical and bacterial meningitis caused by a lumboureteral shunt failed to improve dramatically. When our patients are combined with 40 in the literature treated by decompression and duraplasty, 51 of 55 patients had reduction or resolution of the syrinx. Although it does not clearly affect the result, resection of the tonsils can be done safely.     

Surgical treatment of posterior fossa tumors in infancy and childhood: techniques and results

Fetal/neonate kidneys obtained at the time of autopsy were utilized to determine a suitable needle biopsy gauge to obtain renal parenchyma for histologic evaluation. Twenty-one fresh kidney specimens from 11 fetuses/neonates between 16-40 weeks gestation were used to obtain needle biopsies using 20-, 18-, 16-, and 14-gauge biopsy catheters. The specimens were graded according to the presence of normal histologic features of renal parenchyma. Seventy-five renal biopsies were obtained. The biopsy histology was interpreted using a grading system based on the presence of normal features of the renal parenchyma. Sixty-three (84%) of the samples were graded histologically as adequate (cortex or medulla present). Samples with both cortex and medullary structures present (completely adequate) were obtained in 39/63 (62%) of these adequate biopsies. The 14- and 16-gauge biopsy catheters gave the best results, respectively yielding 79 and 69% completely adequate biopsies. This is in contrast to the 20- and 18-gauge catheters that respectively yielded 35 and 25% completely adequate biopsies. Our initial results indicate that adequate kidney biopsies can be obtained. However, the current technique is associated with core sample disruption when the smaller gauge catheters are used. This could account for the low rate of completely adequate samples with the smaller gauge catheters. A different sampling technique is needed to overcome sample disruption, to determine the smallest catheter gauge that will yield a suitable tissue sample for histologic evaluation.     

Manifestations of thalamic tumors in children

On the basis of observation of 11 cases of thalamic tumours in children at various age the author discusses differences in symptoms and signs in relation to the same tumours in adults. The first pathological sign was most frequently hemiparesis without, however, typical characteristics of classical spastic hemiparesis. Later on various involuntary movements appeared, most frequently bilaterally. In half of these cases infection, vaccination, cranial trauma or excessive effort were the factors provoking the appearance of first symptoms. Typical symptoms of raised intracranial pressure developed late and were present in some cases only. The course of the disease was chronic, the survival time up to several years. The results of vertebral angiography were of decisive significance for the diagnosis. Carotid angiography showed only internal hydrocephalus without giving any more detailed clues as to the location of the process.     

Posterior polymorphous dystrophy associated with astigmatism and amblyopia in children

BACKGROUND: Posterior polymorphous dystrophy has been described in the scientific literature as having more than a casual association with keratoconus in adults. We studied four consecutive children with posterior polymorphous dystrophy who had coexisting astigmatism. In our patients, the posterior changes appeared to be associated with the corneal astigmatism, as evidenced by videokeratography. METHODS: Four consecutive cases of posterior polymorphous dystrophy in children were found over a 3-year period by one of the authors (PD). They presented with varying degrees of amblyopia in the eyes with the greater amount of posterior polymorphous dystrophy. Cycloplegic refractions and keratometry readings were performed. The more affected eyes had greater degrees of astigmatism, presumably causing the amblyopia. Whenever possible, the results were supplemented by confirmation by a corneal specialist, specular microscopy, slit-lamp photographs and videokeratography. RESULTS: Greater asymmetry of posterior polymorphous dystrophy was associated with greater astigmatism in the more affected eye. When more astigmatic anisometropia was present there was a greater amblyopia. Videokeratography of one of the patients showed that an area of confluent blebs forming a crescent shape compared exactly with a steep cylinder along the same axis. With-the-rule astigmatism was associated with a more diffuse pattern of blebs. CONCLUSION: Decreases in visual acuity in children with posterior polymorphous dystrophy may sometimes be due to an amblyopia caused by the astigmatism of asymmetric disease.     

增强CT三维重建在颞下咽旁间隙肿瘤中的应用

目的:应用Mimic,软件重建颞下咽旁间隙肿瘤增强CT影像中的颅骨、血管及肿物,探讨三维CT重建技术在颞下咽旁间隙肿瘤的诊断及术前手术设计的临床意义.方法:选取4个颞下咽旁间隙肿瘤患者,利用Siemens16排螺旋CT薄层扫描技术,基于2 mm层厚,Mimics 软件直接读人Dicom格式原始数据,利用表面阴影重建法分别重建血管、颅骨及肿瘤,显示其空间关系.结果:观察三维重建图像,可以清晰显示肿瘤范围、大小、位置及其与血管和颅骨的关系.结论:利用Mimics软件三维重建增强CT可以清晰显示颞下咽旁间隙肿瘤的特征及其与颅骨、血管关系,有利于手术方案设计,可以避免手术中损伤重要解剖结构.     

Thoracic tumors in children with neurofibromatosis-1

Lymphocytes were isolated from volunteers before and after receiving a single supplement of vitamin C, vitamin E or beta-carotene. The lymphocytes were treated with H2O2, and DNA strand breaks were measured by single cell gel electrophoresis (the comet assay). Significant protection against oxidative DNA damage was evident 2-4 h after vitamin C intake, and 18-24 h after consumption of the other antioxidants. Lymphocytes from smokers were more sensitive to DNA damage than those from non-smokers, and they showed at least as great a protective effect with antioxidants.