Junsuke Katsuyama

MR appearance of Rathke's cleft cysts

SummaryTwo of three patients who proved to have symptomatic Rathkes cleft cysts presented with visual field deficit and all with diabetes insipidus. CT showed intra- and suprasellar cystic low density lesions with ring enhancement. MR showed intra-and suprasellar masses. On the T1-weighted images two of the three had hyperintense portions similar to fat and the other a hyperintense portion similar to white matter within the cysts. These portions were isointense to brain on the T2-weighted images in all cases. This characteristic intensity on MR images provides differentiation from cystic pituitary adenomas and cystic craniopharyngiomas, and leads to correct diagnosis of Rathkes cleft cyst.

Intradural chordoma: case report and review of the literature

Chordomas are rare neoplasms arising from notochordal remnants found predominantly in the clivus and the sacrococcygeal regions. Most clivus chordomas show extradural extension and bone destruction. Such a tumour can rarely be intradural. This report is concerned with the radiological findings in prepontine intradural chordoma.

Multiple appearing and vanishing aneurysms: primary angiitis of the central nervous system. Case report.

The authors present the case of a patient with ischemic episodes and recurrent intracerebral hemorrhages probably caused by primary angiitis of the central nervous system (CNS). An initial angiogram revealed multiple cerebral artery aneurysms as well as vascular wall irregularity; a second angiogram obtained 2 years later, however, did not demonstrate the previous aneurysms but instead showed new ones together with stenosis. Based on the histopathological findings and clinical course in this case, the multiple aneurysms appear to have been induced by vascular wall fragility and subsequent self-repair resulting from primary angiitis of the CNS. The authors present the histological and clinical characteristics of this unusual case of granulomatous, necrotizing CNS vasculitis.

Magnetic resonance imaging of infiltrating angiolipoma of the neck

Although infiltrating angiolipomas are histologically benign, recurrence has been reported in more than 50% of patients after partial extirpation. The authors have treated a 14-year-old female with a large infiltrating angiolipoma of the neck, in whom magnetic resonance imaging was more valuable than x-ray computed tomography and angiography in delineating the extent of the tumor. Total removal of the tumor was performed with the aid of an operating microscope. To our knowledge, this is the first description of the magnetic resonance imaging of an infiltrating angiolipoma. When other neuroradiologic examinations cannot be considered to demonstrate the extent of the tumor accurately, magnetic resonance imaging may be recommended.

Proliferative potential of meningiomas evaluated by proliferating cell nuclear antigen expression

Meningiomas are principally benign in nature. Some meningiomas, however, grow fast or recur even after total removal. The biological behavior of meningiomas often can not be predicted from conventional histopathological studies. A monoclonal antibody against proliferating cell nuclear antigen (PCNA) was used to investigate the usefulness of the PCNA index as a parameter to estimate the proliferative activity of meningiomas. Fifty-two meningiomas were examined. The mean PCNA index of recurrent meningiomas (3.37±0.92%) was significantly higher than that of non-recurrent meningiomas (1.12±0.51%) (p <0.005). The PCNA indices of recurrent cases were all higher than 2.0%. A semilog linear regression analysis between tumor doubling time and PCNA index showed a significant correlation (r=0.90, p < 0.05). An inverse linear correlation between PCNA index and interval to recurrence was observed (r=0.62, p < 0.05). A good linear correlation was also shown between PCNA index and BUdR labeling index (r = 0.88, p < 0.01). The results of this study suggest that, providing the methods of tissue processing, immunostaining and counting of positive nuclei are unified, the PCNA index is a useful parameter for estimating the biological behavior of meningiomas.

Giant basal prolactinoma extending into the nasal cavity

An unusual case of a giant prolactinoma extending to the nasopharynx and nasal cavity is presented. A 35-year-old man admitted for nasal obstruction and visual disturbances was found to have bilateral anosmia, right homonymous hemianopsia, and a right hemiparesis. The serum prolactin level was 13,300 ng/mL. Radiological examination revealed a large mass invading the skull base and extending into the suprasellar region and the left frontal lobe superiorly and into the nasopharynx inferiorly. Subtotal removal was done through a bilateral orbitofrontal craniotomy, which was followed by radiotherapy and bromocriptine administration. Immunohistochemical analysis confirmed a prolactinoma. The rarity of such a tumor, its location and extension, and the usefulness of magnetic resonance imaging and immunohistochemistry are stressed. Pertinent literature is reviewed.

Effects of electrical stimulation on intracranial pressure and systemic arterial blood pressure in cats. Part II: Stimulation of cerebral cortex and hypothalamus.

This experimental work was carried out to examine whether activation of autonomic cortical and hypothalamic areas by electrical stimulation is related to changes in the intracranial pressure (ICP) in cats anaesthetized lightly with sodium pentobarbital. Electrical stimulation was performed using a concentric electrode with a train of electrical pulses (pulse duration, 0.4 ms; frequency, 40 Hz; intensity, 50-400 microA). Stimulation of sites in the anterior cingulate gyrus produced a rise in ICP associated with a fall in systemic arterial blood pressure (BP) or with no change in BP. Stimulation of sites in the anterior hypothalamus produced a fall in BP with an increase in ICP. Stimulation of sites in the area extending from the anterior hypothalamus to the posterior hypothalamus produced rises in BP and ICP. These observations suggest that activation of autonomic cortical and hypothalamic areas is involved in changes in ICP.

Effect of Steroids on the Resolution Process of Edema

The mechanism of the action of steroids on brain edema is not fully understood despite its long history. Recently it has been reported that the beneficial effect of steroids might be attributed to inhibition of edema spread or acceleration of edema resorption (Matsuoka, Hossmann 1981; Hossmann et al. 1983; Fenstermacher et al. 1984; Hartmann et al. 1984). Almost all experimental models of edema must involve the formation process and the resolution process of edema which can not be separated from each other experimentally. Using the direct infusion model of edema, the only model in which one can separate these two processes, the question of whether the effect of steroids is exerted on the resolution process was investigated.

Microsurgical Removal of Intramedullary Spinal Cord Tumours: Report of 22 Cases

The management of patients with intramedullary spinal cord tumours is controversial. The authors have treated these tumours in accordance with the principles of radical resection, using micro-surgical techniques. There have been 22 cases of intramedullary spinal cord tumours (4 astrocytomas, 3 glioblastoma multiformes, 5 ependymomas, 7 haemangioblastomas, 1 dermoid, 1 lipoma and 1 schwannoma) thus treated at our department during the past 13 years. Sixteen were adults and six were children. The early and late results of their surgical treatment have been analyzed, with follow-up periods ranging from 10 months to 12 years. Of the 22 patients, total removal was performed in 16, subtotal removal in 5 and biopsy in 1. Guidetti’s criteria were adopted in assessing the results of surgery. Long-term results were as follows: 8 very good, 5 good, 3 fair, 3 poor and 3 deceased. The 3 latter cases were glioblastoma multiformes. Gross total removal of intramedullary tumours is technically feasible and compatible with neurological recovery. Since the majority of intramedullary tumours are benign and their course may span not only years but decades, long-term follow-up is essential.

Delayed Opening of the Blood-Brain Barrier in Direct Infusion Edema Model

Marmarou et al. developed a unique model for studying brain edema by infusing a relatively large amount of fluid into the white matter [2]. Such intraparenchymal infusion did not induce local breakdown of the blood-brain barrier (BBB): the BBB was found intact at 0 hour, 72 hours and at 7 days after the infusion [1]. Therefore, this model could be considered suitable for investigations on the resolution process of brain edema in terms of no new edema fluid supplied from the blood vessels. A recent study using this model showed that the fluid infused into the brain migrated, in an extremely short period after infusion, to the ventricular system and also to the cortical surface [4]. Such a fast movement of fluid along the intraparenchymal vessels may change their permeability in a short time after the infusion. In the present study we reinvestigated the effect of intraparenchymal infusion on the BBB within 24 hours after the infusion.