ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEAn applicator system for the Leksell G frame was constructed to enable accurate placement of the frame for stereotactic magnetic resonance imaging (MRI) and successful stereotactic surgery. The applicator prevents inaccurate placement of the fiducial box on the patient’s head and prevents contact of the frame holder with the patient’s shoulder while in the MRI unit. It also helps to ensure optimal positioning of desired targets within the three-dimensional stereotactic space defined by the frame.METHODSThe applicator is made of transparent acrylic plates, which simulate the fiducial box that is attached to the frame for the preoperative stereotactic MRI study. An air cuff at the top supports the frame at any desired height and makes minute adjustments possible. Side cuffs help to keep the frame at the desired position from right to left. Indicators attached to the frame for the anterior fiducial plate prevent potential contact of the plate with the anterior posts and help avoid a poor fit caused by bending of the frame from excessive torque on the cranium fixation screws. Indicators for the MRI frame holder on the foot screws predict potential collision of the holder with the patient’s shoulder before actually applying the holder on the frame. The applicator shows the range and limits of the Leksell stereotactic arc.RESULTSThis applicator system has been used effectively in more than 89 MRI-based functional stereotactic procedures. These include pallidotomy, thalamotomy, implantation of deep brain stimulators, and implantation of depth electrodes. It has functioned well and has facilitated excellent operative results in these cases.CONCLUSIONThis simple frame applicator eliminates the need for reapplication of the stereotactic frame and additional imaging studies, thus providing successful and appropriate frame placement for stereotactic surgery.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVETo test the efficacy of a simple technique of frontal sinus obliteration during low frontal craniotomy using hydroxyapatite cement instead of more traditional methods, such as pericranial flaps, free muscle or adipose grafts, lumbar drainage, or fibrin glue.METHODSEight patients undergoing low frontal craniotomy for intradural surgery had the frontal sinus obliterated by careful removal of mucosa followed by filling of the sinus with hydroxyapatite bone cement. No other adjuncts for preventing cerebrospinal fluid leakage through the sinus were used.RESULTSAt an average follow-up of 9 months, there were no cerebrospinal fluid leaks, infections, instances of resorption, or cosmetic deformities.CONCLUSIONHydroxyapatite bone cement seems to be a simple and effective method for frontal sinus obliteration and prevention of cerebrospinal fluid leakage.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVE AND IMPORTANCESymptomatic basilar artery stenosis has a poor prognosis. Treatment options are limited. Surgical bypasses are technically demanding and of no proven benefit. Percutaneous angioplasty is associated with a significant complication rate, because of intraplaque dissection, restenosis secondary to vessel recoil, and embolic phenomena. A new generation of intravascular stents that are flexible enough to navigate the tortuosities of the vertebral artery may provide a new therapeutic approach. We report a case of basilar artery stenosis that was treated using stent-assisted angioplasty.CLINICAL PRESENTATIONA 56-year-old woman experienced a vertebrobasilar ischemic stroke, from which she recovered. Magnetic resonance angiography revealed severe proximal basilar artery stenosis. Brain Neurolite-single-photon emission computed tomographic scans revealed significantly decreased perfusion of the brainstem. Endovascular intra-arterial pressure measurements revealed a 35-mm Hg gradient across the lesion.INTERVENTIONThe patient underwent uncomplicated angioplasty and stenting of the proximal basilar artery, with excellent angiographic results.CONCLUSIONThe availability of new flexible intravascular stents, allowing access to tortuous proximal intracranial vessels, provides a new therapeutic approach for patients with basilar artery stenosis. Long-term follow-up monitoring is required to assess the durability of this approach.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEMultiple meningiomas are uncommon brain tumors occurring concurrently in several intracranial locations in the same patient. In the present study, we determined the clonality, methylation status of deoxyribonucleic acid, and relationship of genetic alterations in eight meningiomas from one female patient.METHODSSix molecular genetic techniques, including two methylation-based clonality assays and one transcription-based clonality assay, methylation analysis of CpG islands by methylation-specific polymerase chain reaction, loss of heterozygosity, microsatellite instability, and mutational analysis of theNF2gene on chromosome 22, were used in comparative investigations on clonality and genetic alterations.RESULTSThe presence of clonal tumor cells was demonstrated by 1) loss of the same copy of chromosome 22 in all eight tumors; 2) transcription of the humanARgene from the same allele in six of eight tumors; 3) a common unmethylated allele at theARlocus in all eight tumors; and 4) the identical single-basepair insertion mutation in exon 9 of theNF2gene in six of eight tumors. In addition, loss of a copy of the X chromosome in one tumor nodule and microsatellite instability in another nodule were observed.CONCLUSIONTaken together, this case of multiple meningiomas was most likely monoclonal in origin. Loss of chromosome 22 was an early event during the development of multiple meningiomas and was followed by mutations at theNF2locus. Later events, including loss of the X chromosome, variation ofARgene expression, or microsatellite instability, may also have played a role in the development of multiple meningiomas in this patient.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID