Publications by authors named "Masahito Katoh"

Background:  It is very rare for a choroid plexus tumor to occur intraparenchymally in the absence of a relation to the choroid plexus.

Clinical Presentation:  A case of cerebral intraparenchymal choroid plexus tumor in a 30-year-old woman presenting with left hemiparesis is described. Brain magnetic resonance imaging depicted a large cystic mass in the right frontal lobe.

View Article and Find Full Text PDF

Introduction: It is well-known that localized reversible high signal intensities in the splenium of the corpus callosum or the basal ganglia appear on diffusion-weighted MRI in the presence of hypoglycemia. The aim of this study was to clarify the incidence and significance of such high signal intensity lesions.

Results: We analyzed 70 cases of hypoglycemia with consciousness disturbance referred to our outpatient office.

View Article and Find Full Text PDF

Temozolomide (TMZ) is an oral alkylating agent which is widely used in the treatment of glioblastoma (GBM) and is composed of astrocytic and/or oligodendroglial tumors, and the evaluation of O(6) -methylguanine DNA methyltransferase (MGMT) expression is important to predict the response to TMZ therapy. In this study, we conducted immunohistochemical analysis of 117 cases of Japanese GBM including 19 cases of GBM with oligodendroglioma component (GBMO), using a scoring system for quantitative evaluation of staining intensity and proportion of MGMT, and performed survival analysis of these patients. Immunohistochemically, 55 cases (47%) were positive for MGMT with various intensities and proportions (total score (TS) ≥ 2), while 62 cases (53%) were negative (TS = 0).

View Article and Find Full Text PDF

It is important to predict the outcome of tissue plasminogen activator (tPA)-treated patients early after the treatment for considering the post-tPA treatment option. We assessed cerebral blood flow (CBF) of tPA-treated patients with single-photon emission computed tomography (SPECT) 1 hour after tPA infusion to predict the patient outcome. Technetium-99m-hexamethylpropyleneamine oxime SPECT was performed in 35 consecutive tPA-treated patients.

View Article and Find Full Text PDF

It is well-known that idiopathic neuralgias of the trigeminal and glossopharyngeal nerves are caused by vascular compression at the root entry zone of the cranial nerves. Because they are functional diseases, initial treatment is medical, especially with carbamazepine. However, if medical therapy fails to adequately manage the pain, microvascular decompression (MVD) is prescribed.

View Article and Find Full Text PDF

Atypical teratoid/rhabdoid tumor (AT/RT) is a malignant tumor that mostly occurs in early childhood and has poor prognosis despite aggressive therapy. Adult cases are rare and, as far as we are aware, only 30 cases have been reported to date. Here we present the case of a 27-year-old female with left parietal AT/RT with the chief complaint of numbness of the right superior limb.

View Article and Find Full Text PDF

Spontaneous regression of an intracranial mass is rare. We report a 77-year-old man with spontaneous regression of an anterior skull base mass suspected to be an inflammatory pseudotumor. The patient attended our outpatient department approximately once per month for a regular check-up following a brain stem infarction.

View Article and Find Full Text PDF

Supplementary motor aphasia results from impairment of the supplementary motor area in the left mesial frontal cortex. We report a rare case of subarachnoid hemorrhage presenting with supplementary motor aphasia as an initial symptom. A 52-year-old woman was brought to our hospital by ambulance due to sudden severe headache and supplementary motor aphasia.

View Article and Find Full Text PDF

Evaluation of O6-methylguanine-DNA methyltransferase (MGMT) expression is important for antiglioma therapy as many clinical trials have demonstrated that promoter hypermethylation and low level expression of MGMT are associated with an enhanced response to alkylating agents. However, here we report that the current strategies used to evaluate MGMT status in gliomas are unreliable. We observed discordance in the MGMT expression status when immunohistochemical evaluation and polymerase chain reaction-based methylation assessments were used: 73% of gliomas with methylated MGMT promoter had substantial numbers of MGMT-immunopositive tumor cells.

View Article and Find Full Text PDF

Background: Cerebral amyloid angiopathy is a well-known disease that is predominantly recognized in elderly people and repeatedly causes large subcortical hemorrhages. These hemorrhages may be derived from vessel wall weakness because of Abeta depositions in the wall of the cortical and leptomeningeal arteries. Although vessel ruptures in CAA have been thought to occur in cortical arteries, it was recently demonstrated that the primary hemorrhage occurs in the subarachnoid space, particularly the cerebral sulci, as a result of multiple ruptures of meningeal arteries in some cases of subcortical hematoma caused by CAA.

View Article and Find Full Text PDF

Although vestibular schwannoma is a common tumor in the cerebellopontine angle, calcified vestibular schwannoma is rare. A 59-year-old woman with sudden onset epileptic seizures, was referred to Hokkaido Neurosurgical Memorial Hospital. Neurological examination revealed left Bruns nystagmus, left deafness and left cerebellar ataxia.

View Article and Find Full Text PDF

Two cases of clear cell ependymoma (CCE) of the fourth ventricle are reported in a 49-year-old woman with dysphagia and a 59-year-old woman with dizziness and gait disturbance. CCE is a relatively new variant of ependymoma added to the WHO classification of tumors in 1993. Tumor cells display an oligodendroglioma-like appearance with a clear perinuclear halo.

View Article and Find Full Text PDF

Survivin, a member of the inhibitor of apoptosis proteins gene family, was recently shown to be expressed by tumors originating from different cell lineages. There are also cumulative evidences that spontaneous immune response against survivin derived epitopes may occur. Here, using RT-PCR, Western-blot analysis and immunohistochemistry, we show that survivin is widely expressed by gliomas, meningiomas and schwannomas, both in vitro and in vivo.

View Article and Find Full Text PDF