We report a case of meningioma diagnozed 23 years after high-dose cranial and whole-body irradiation for the treatment of acute lymphocytic leukemia (ALL). Radiotherapy in this case also caused early radiation injury to the lenses and the pituitary gland, with growth retardation and mineralizing angiopathy. Radiation-induced meningiomas are more commonly malignant, more commonly multiple, and more likely to recur after resection than non-radiation-induced meningiomas. Survivors of childhood ALL treated with high-dose cranial irradiation are at risk both for early radiation injury in radiosensitive organs, such as the lens and pituitary gland, and for the later development of a radiation-induced meningioma.

BACKGROUNDCerebral germinomas and their occasional recurrences can usually be cured by irradiation, chemotherapy, or a combination of the two treatment modalities. Late recurrences, as in our case, are distinctly rare. CASEDESCRIPTIONThis patient presented at age 24 with a calcified tumor in the pineal area. The radiological diagnosis was germinoma. No tissue diagnosis was obtained. Radiation therapy was given, and there was a complete response. The patient's symptoms reappeared 13 years later. Imaging studies revealed a lesion in the anterior corpus callosum. A germinoma was diagnosed by stereotactic biopsy. Because of complications attributed to the initial course of radiation therapy, no further radiation was given. Five courses of chemotherapy resulted in a partial remission lasting six months. The patient later died because of massive tumor progression with intracerebral, intraventricular, cerebellar, and meningeal dissemination.CONCLUSIONSAs this case illustrates, exceptional recurrences of cerebral germinomas may appear even many years after adequate initial treatment with radiation and chemotherapy. (C) 2002 by Elsevier Science Inc.

The supracerebellar transtentorial (SCTT) approach, a modification of the infratentorial supracerebellar approach, facilitates simple and minimally invasive access to posterior temporomedial structures without requiring retraction of the temporal or occipital lobe. The SCTT approach was used in 16 patients over a 3-year period. Eleven patients harbored tumors confined to, or located mainly within, the posterior hippocampal formation, three patients harbored aneurysms (one ruptured posterior cerebral artery [PCA] aneurysm at the P2-P3 junction, one ruptured giant PCA [P2] aneurysm, and one giant basilar artery-superior cerebellar artery aneurysm), one patient had juvenile-type moyamoya disease, and one patient suffered from medically intractable epilepsy. In these patients, the SCTT approach enabled tumor removal, aneurysm clipping, and vascular bypass procedures. The authors' experience suggests that this approach can be used routinely in treating lesions in the posterior temporomedial region.

Rathke's cleft cysts usually present with an intrasellar or a combined intrasellar and suprasellar localization. In this report we present a 58-year-old man with a Rathke's cleft cysts in an entirely suprasellar location with intact diaphragm and intact sella. Although this presentation of a Rathke's cleft cyst is extremely rare, it belongs in the differential diagnosis of entirely suprasellar lesions. The relevant literature is discussed.

around the tentorial notch may be gained by occipital interhemispheric, subtemporal, or temporal transventricular approaches. Each approach carries its own inherent risk of compromising visual fields and/ or language function (when performed in the dominant hemisphere) because of the need for retraction or cortical incision. The SCTT approach was devised to avoid these risks and was originally reported, as far as we can determine from our review of the literature, by Voigt and Yasargil20 in 1976 for removal of a cavernous angioma in the left parahippocampal gyrus. In this communication we describe our experience in using the SCTT approach to structures such as the posterior hippocampal formation and the PCA (P2 and P3 segments), which does not place these highly important functional areas at risk. Clinical Material and Methods

Ninety-eight patients with aneurysms of the posterior circulation were admitted to our department from 1993 to 1997. Sixty of them underwent microsurgical treatment, mostly in the acute stage of subarachnoid hemorrhage. Peri- and intraoperative management were carried out according to a structured treatment strategy. Special aspects of surgical technique included extradural selective anterior clinoidectomy for basilar head aneurysms, lateral suboccipital craniotomy and partial condylectomy without laminectomy for aneurysms of the vertebral artery or posterior inferior cerebellar artery, and a trans-Sylvian approach, as used in selective amygdalohippocampectomy, for aneurysms of the posterior cerebral artery. A careful angiographic evaluation of the aneurysms in relation to the neighboring important arteries and bony structures was essential for optimal surgical planning. Forty-nine patients (82%) made a good recovery by 3 months after surgery. The mortality was 7%.

BACKGROUND- Moyamoya disease (spontaneous occlusion of the circle of Willis) is a rare disease, previously thought ;to be confined to Japan and other Asian countries, but now known to occur worldwide, although at a lower frequency. Information about its correct diagnosis and appropriate treatment is frequently requested, especially in Europe and the United States.REVIEW SUMMARY- The clinical features of Moyamoya disease are now well established, as is its treatment, which is directed against cerebral ischemia. It is possible that Asian, American, and European patients differ in some ways in the clinical expression of the disease. Similar clinical features associated with other systemic diseases should be referred to as Moyamoya syndrome, rather than Moyamoya disease. The prognosis with regard to life expectancy is relatively favorable, but the associated impairment of intellectual development is currently drawing more attention. Revascularization procedures reportedly improve the prognosis in this regard. The optimal choice of revascularization procedure remains under discussion. Recent scientific developments include the application of molecular biological techniques, such as testing for basic fibroblastic growth factor in the vascular wall and in the cerebrospinal fluid, and genetic analysis of familial cases, which account for approximately 10% of all cases, in the search for the still unknown etiology of the disease.CONCLUSION- The principal clinical manifestations of Moyamoya disease are cerebral ischemia in children and intracranial bleeding in adults. These are caused by the severe stenosis or occlusion of the internal carotid artery at its terminal portion bilaterally, which induces the formation of abnormal vasculature (Moyamoya) in the basal ganglia. it is treated by the administration of aspirin to prevent progression of the disease and by a revascularization procedure to augment the cerebral blood flow.

It should never be forgotten that there is far more to microsurgery than the mere possession of a highly perfected optical instrument. Without bipolar coagulation, specialized instruments, and, above all, knowledge and skill in atraumatic microtechniques, the microscope alone is of little value. Perfection of atraumatic microsurgical technique is best acquired by operating on small-diameter blood vessels (0.8 mm to 1.5 mm) in animals.

To evaluate the results of a structured treatment approach to aneurysm surgery in the acute stage, 150 consecutive patients with aneurysmal subarachnoid hemorrhage were studied, including 46 males and 104 females; World Federation of Neurological Surgeons grade I: 21 cases, II: 65, III: 41, IV: 23; day of operation < or = day 3: 103 cases, < or = day 7: 131. Patients underwent angiography on the day of admission or the next followed by surgery. The lamina terminalis and the membrane of Liliequest were routinely opened at surgery. The aneurysm neck was radically clipped after temporary clipping or trapping of the parent arteries. Intraoperative hemodynamic monitoring was used, and the craniotomies were closed without cisternal, epidural, or subgaleal drains. Nimodipine was given perioperatively (48 mg i.v./day for 10 to 14 days). Cases of symptomatic vasospasm were treated with selective intra-arterial administration of papaverine, sometimes combined with angioplasty. Outcome at discharge and 3 months later is good recovery in 61% and 75%, and death in 6% and 7%. The incidence of symptomatic vasospasm was 17%. Devastating vasospasms were observed in 5%. One-third of patients had mean flow velocities exceeding 120 cm/sec determined by transcranial Doppler sonography between days 4 and 14. Communicating hydrocephalus necessitating ventriculoperitoneal shunt occurred in 9%. Our results clearly show a favorable outcome compared with previous reports, especially with respect to the reduced occurrence of fatal vasospasm, hydrocephalus, and technical insufficiency.

A questionnaire was distributed in early 1996 to 160 leading European neurological, neuro-pediatric and neurosurgical centers to assess the present status of Moyamoya disease in Europe. The response rate was 43%. Information was obtained on a total of 168 patients, of whom 110 had presented before 1992, and 58 from 1993 onward. 82% of the patients were Caucasian. In all other respects, the clinical findings were similar to those observed in Japan. The present study yields an incidence of 0.3 patients per center per year, which is approximately one-tenth of the incidence in Japan. Alongside these results, the history of the recognition and treatment of this disease in Europe is briefly discussed.

The phenomenon of non-Fourier motion (visually perceived motion that cannot be explained simply on the basis of the autocorrelation structure of the visual stimulus) is well recognized, and is generally considered to be due to nonlinear preprocessing of the visual stimulus prior to a stage of standard motion analysis. We devised a sequence of novel visual stimuli in which the availability of a motion stimulus depends on the nature of the nonlinear preprocessing: an nth order stimulus Pn will generate a perception of motion if it is preprocessed by a nonlinearity of polynomial order n or greater, but not if preprocessed by a nonlinearity of polynomial order less than n. We found that unambiguous motion direction was perceived for P2, P3, and P4, but not for higher-order stimuli, and we measured the contrast thresholds for direction discrimination with superimposed noise. We found that an asymmetric compressive nonlinearity can, in a unified fashion, account for these results, while a purely quadratic nonlinearity or a rectification of the form T(p) = |p| cannot. We compared velocity discrimination judgements for second-order non-Fourier stimuli (P2) with standard drifting gratings. Although velocity comparisons were veridical, uncertainties were greater for the non-Fourier stimuli. This could be reproduced by substituting a Fourier grating with superimposed noise for the non-Fourier grating. These findings are consistent with a single pathway which processes both Fourier and non-Fourier short-range motion, and are discussed in the context of other investigations which have been interpreted as demonstrating separate pathways. © 1997 Elsevier Science Ltd.

THORACIC COMPLICATIONS OF ventriculoperitoneal shunts are rare, but potentially serious. The authors report a case of a drainage of cerebrospinal fluid into the tracheobronchial tree through a peritoneal shunt catheter that migrated into the chest. After injection of contrast material into the shunt, a plain radiograph of the chest revealed a bronchogram. The symptoms resolved after a revision of the shunt. Published case reports of this and other thoracic complications of ventriculoperitoneal shunts are comprehensively reviewed. A classification of such complications into three types is proposed as follows: intrathoracic trauma during placement of a shunt, migration of the peritoneal catheter into the chest (by either a supradiaphragmatic or a transdiaphragmatic route), and pleural effusion accompanying cerebrospinal fluid ascites. The possible mechanisms and contributing factors are discussed.