Critical reviews in neurosurgery : CR最新文献

We reviewed seven recent articles that discuss the risk factors associated with the hemorrhagic presentation of cerebral arteriovenous malformations (AVMs). Although several such factors have been identified, only nine have been shown to be independent predictors of AVM hemorrhage by multiple logistic regression. All of the studies reviewed are subject to biases that compromise their ability to identify risk factors for hemorrhage confidently. A prospective, multicenter, controlled trial would be necessary to identify such risk factors with certainty.

Meningiomas involving the cavernous sinus present the neurosurgeon with different choices: observation, microsurgery, or radiosurgery. During the last decade, advances in microsurgical techniques have significantly lowered the treatment-related morbidity, and some neurosurgeons have reported long-term follow-up results. Recently, several radiosurgical series have reported excellent tumor control and good functional preservation for tumors in this area. Most of these series do not provide complete information about the patient's cranial nerve function, and objective and subjective outcome data. The follow-up provided has also been short, considering that meningiomas have a tendency to recur or regrow up to 20 years postoperatively. There is also the concern about those patients who fail radiosurgical treatment, since microsurgery does not yield good results in such cases. In this paper, several radiosurgical series are critically reviewed, with a discussion about the pros and cons of microsurgery versus radiosurgery. The authors suggest that a uniform reporting strategy be adopted by all surgeons treating tumors of this area, which will allow comparative studies to be conducted. Additionally, we suggest a treatment algorithm for cavernous sinus meningiomas, based on the patients age, occupation and preference, preoperative binocular function, and curability of the tumor.

Dysembryoplastic neuroepithelial tumors (DNTs) were first described in 1988. A DNT is a cortical tumor that produces enlargement of a gyrus, forming a megagyrus that exceeds the normal thickness of the cortex. This tumor is generally seen in young patients with a long-standing history of drug-resistant and disabling seizures mostly of the complex partial type. No neurological deficits are found between the interictal periods in the majority of the reported cases. A general agreement exists over the clinical and radiological manifestations of a DNT as well as the benign biological behavior. Two pathological variants of DNT have been recognized: the single form, composed only of the so-called specific glioneuronal element, and the complex form that additionally shows glial nodules and foci of cortical dysplasia. Nevertheless, and despite the benign biological course, nuclear atypias, cellular monstruosities, foci of necrosis and mitosis can also be found. Surgical eradication of the tumor will usuallly have a good prognosis, without recurrences and with a positive control to seizure-free clinical outcome. Controversy continues to exist over a hamartomatous or a neoplastic origin of this lesion. The DNT has been placed among the neuronal and mixed neuronal-glial neoplasms in the revised World Health Organization (WHO) brain tumor classification, a category that includes the gangliogliomas and the central neurocytomas. Ultrastructural studies and immunostaining techniques may suggest that these three lesions represent different spectrums of the same condition. This paper reviews the most recent publications to offer a better understanding of DNTs and their implications in diagnosis and management.

For years, many controversies have arisen on the surgical management of trigeminal neuralgia and neuropathy. The purpose of this paper is to review most of the current surgical techniques for the management of trigeminal neuralgia and present our position on the current management of these situations.

This review looks at papers dealing with radiosurgery for tumors, cavernous malformations, and arteriovenous malformations. The tumors were meningiomas, many of them at the base of the brain, and the results were excellent. One paper used the gamma knife for patients with cavernous malformations. The authors encountered significant morbidity and concluded that these lesions should be treated surgically. There are two papers dealing with arteriovenous malformations. One of these showed that a significant number of arteriovenous malformations were not obliterated. The second report was on arteriovenous malformations treated with radiosurgery, and the authors found that some of the patients developed hemiparkinsonism and hemiparesis.

Since the publication by F. Vourc'h in 1963 [Br J Anaesth (1963) 35:118-120] describing the use of a plastic catheter inserted percutaneously for the drainage of lumbar cerebrospinal fluid (CSF) the indications for spinal drainage are numerous, but not very well systematized. The bibliographical review shows few recent papers concerning the techniques, indications, complications and pitfalls. The authors considered it interesting to analyze nine papers, in particular those dedicated to the use of spinal drainage in skull base surgery and in the prevention and/or treatment of CSF fistulas. Two papers describe for the first time pachymeningeal gadolinium enhancement associated with orthostatic headaches, owing to CSF hypotension mimicking an inflammatory or infiltrative disease. The results of the treatment of CSF fistulas are good with a high success rate, avoiding direct surgical repair. The use of a specially designed subarachnoid catheter is clearly superior to the epidural catheter, with good flow of CSF and minimal complications. The main problems are deficient flow and infections. Overdrainage is potentially dangerous, with acute pneumocephalus, brain collapse and neurological deterioration. Infrequent but possible is Chiari II-like syndrome with vocal cord paralysis and life-threatening aspiration, or temporal downward herniation with kinking of the posterior cerebral artery and acute brain infarct. The key to success lies in a rigid protocol, intermittent CSF drainage with a closed circuit, and daily biochemical and microbiological monitoring. Highly qualified medical and nursing staff are essential.

The management of thalamic and brain stem astrocytomas remains controversial. Treatment options are: (a) clinical observation, (b) radiotherapy without biopsy, (c) stereotactic biopsy followed by radio and/or chemotherapy, and (d) surgical removal with or without adjuvant therapy. Stereotactic surgical techniques have improved the morbidity and mortality rates of biopsies and surgical resection of deep-seated gliomas. The biologic behavior of these lesions is not well known and proliferation cell index tests may help in the choice of therapy. In this review, seven recent papers on the management of deep-seated gliomas are presented. Radical removal of thalamic pilocytic astrocytoma may cure the patient. In cases of low-grade astrocytomas, stereotactic guided surgical removal has low morbidity. Adjuvant radiotherapy should be used only in selected cases. Sterotactic biopsy followed by radio- and/or chemotherapy is the best option for thalamic or brain stem anaplastic astrocytomas and glioblastomas.

Telepathology in general, and teleneuropathology in particular is the practice of pathology at a distance, viewing digitized images of histological slides on a video monitor rather than directly through a light microscope. For the transmission of the digitized images from a telemicroscope to the remote diagnostic video monitor, different technologies such as ordinary telephone lines, broadband telecommunications channels, and even the Internet can be used. The transmitted images may serve for primary neuropathological diagnosis, teleconsultation, quality assurance, proficiency testing, and distance learning. Static imaging and dynamic imaging are the two major competing technologies of telemicroscopy. Static-imaging systems appear to have levels of diagnostic accuracy that are not satisfactory for diagnostic neuropathology. In contrast, high levels of diagnostic accuracy can be achieved using dynamic-imaging systems with the transmission of live video images in real time and by using a robotized telemicroscope under the control of the remote teleneuropathologist with the possibility to examine the entire histological specimen.