Kaku Niimura

Research Institute for Brain and Blood Vessels-Akita, Akita, Akita, Japan

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Publications (7)9.7 Total impact

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    ABSTRACT: Large tumors invading the dorsal part of the anterior third ventricle are difficult to manage. The anterior transcallosal approach is usually used to manage these tumors. In our clinic, anterior callosal section was combined with the anterior interhemispheric (AIH) translamina terminalis approach for these tumors with excellent results. The AIH approach is useful for removing tumors in and around the anterior part of the third ventricle. However, AIH alone is insufficient for large tumors invading the dorsal part of the anterior third ventricle. In such situations, simple anterior callosal section enables the neurosurgeon to extirpate the caudal part of the tumors deeply hidden from operative field, sparing the foramen of Monro, fornix, etc. We treated four large tumors (malignant teratoma, recurrent chordoid glioma, recurrent papillary tumor of pineal region occupying the third ventricle, and paraventricular meningioma) without major complications. The malignant teratoma case exhibited no recurrence with >10 years follow-up. The chordoid glioma and papillary tumor of pineal region were totally removed. The meningioma was subtotally removed except only a small tumor around the bilateral anterior cerebral artery. This simple technique is a new way to manage difficult large lesions in and around the third ventricle.
    Neurosurgical Review 04/2013; · 1.97 Impact Factor
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    ABSTRACT: Papillary tumor of the pineal region (PTPR) is a recently described neoplasm. Several studies have been published on this tumor, but its pathological features and the appropriate treatment remain unclear. PTPR is reported to originate from ependymal cells in the subcommissural organ. Isocitrate dehydrogenase 1 and 2 (IDH1/2) mutations have been a focus area in glioma research as promising predictors. We report a case of PTPR that was characterized by local recurrence, although subtotal removal and radiotherapy seemed effective for many months. Histological examination showed ependymal features in the surgical specimens. As far as we are aware, this case study is the first to show that the IDH1/2 genotypes in PTPR cells are wild-type genotypes, which is consistent with the negative immunoreactivity that was observed for the IDH1 mutant antibody in this study.
    Brain Tumor Pathology 03/2012; · 1.58 Impact Factor
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    ABSTRACT: There are limited indications for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in the treatment of cerebral atherosclerotic disease. However, recent reports emphasize that STA-MCA bypass may be beneficial for select patients. In this report, we describe a case in which a flow-dependent STA-MCA bypass was achieved in a patient with unstable internal carotid artery (ICA) stenosis. A 51-year-old woman presented with left ICA occlusion. A severely elongated mean transit time (MTT) indicated misery perfusion. STA-MCA bypass was performed immediately and blood flow through the graft appeared excellent on magnetic resonance angiography (MRA). Two weeks later, MRA revealed normal anterograde ICA blood flow and the bypass graft was not visible. Three years later, the left ICA stenosis again became severe and the patient developed contralateral hemiparesis. She underwent endovascular surgery and the ipsilateral MCA became occluded during the procedure. The STA-MCA bypass graft appeared immediately after the MCA occlusion and became a major provider of blood flow to the ipsilateral MCA area. She recovered with almost no deficit. This is a rare case which shows that dynamic flow changes through an STA-MCA bypass can occur with variable ICA blood flow. STA-MCA bypass can be beneficial for the treatment of unstable ICA stenosis.
    Surgical Neurology International 01/2012; 3:20. · 1.18 Impact Factor
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    ABSTRACT: Angiocentric glioma (AG) is defined as an epilepsy-associated stable or slowly growing cerebral tumor primarily affecting children and young adults, histologically consisting mainly of monomorphic, bipolar spindle-shaped cells and occasional round to monopolar columnar epithelioid cells, showing angiocentric growth pattern and features of ependymal differentiation. We describe two clinicopathologically unusual cases of AG. Case 1 is a 54-year-old woman with a 10-year history of complex partial seizures. MRI revealed non-enhancing T1-low, T2/fluid-attenuated inversion recovery (FLAIR)-high intensity signal change in the left hippocampus and amygdala. After selective amygdalohippocampectomy, she had rare non-disabling seizures on medication for over 50 months (Engel's class I). Case 2 is a 37-year-old man with a 3-year history of complex partial seizures. MRI revealed non-enhancing T1-low, T2/FLAIR-high intensity signal change in the left uncus and amygdala. After combined amygdalohippocampectomy and anterior temporal lobectomy, he has been seizure-free for over 11 months. Histologically the tumors in both cases consisted mainly of infiltrating epithelioid cells (GFAP- ∼ ± , S-100-) with perinuclear epithelial membrane antigen (EMA)-positive dots and rings, showing conspicuous single- and multi-layered angiocentric arrangements. Occasional tumor cells showed spindle-shaped morphology (GFAP+, S-100+) with rare EMA-positive dots aligned radially and longitudinally along parenchymal blood vessels. Focal solid areas showed a Schwannoma-like fascicular arrangement with rare EMA-positive dots and/or sheets of epithelioid cells with abundant EMA dots. Electron microscopic investigation demonstrated features of ependymal differentiation. These cases, together with a few similar cases previously reported, appear to represent a rare but distinct clinicopathological subset of AG characterized by adult-onset, mesial temporal lobe localization and epithelioid cell-predominant histology.
    Neuropathology 12/2011; 32(5):479-91. · 1.91 Impact Factor
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    ABSTRACT: Spontaneous spinal epidural hematoma (SSEH) is a rare condition, and its etiology remains unclear. Spinal venous wall instability due to intravenous pressure changes and the resultant venous rupture seem to be the underlying pathophysiological mechanisms. Here, the authors report a case of posterior SSEH at the C3-5 level causing mild left hemiparesis in a previously healthy 56-year-old woman. Angiography performed at the time of admission showed left internal jugular vein (IJV) thrombotic occlusion and dilation of the surrounding venous plexus, strongly suggesting that these pathologies caused the SSEH. Furthermore, immediate MR imaging suggested severely impaired blood flow in the left IJV. The hematoma soon resolved after spontaneous IJV thrombolysis. The authors' radiological observations imply that idiopathic IJV thrombosis may cause cervical SSEH.
    Journal of neurosurgery. Spine 04/2011; 15(2):187-9. · 1.61 Impact Factor
  • Nosotchu 01/2010; 32(2):190-196.
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    ABSTRACT: Using magnetoencephalography (MEG), auditory evoked magnetic N100m were measured in patients with focal epilepsy and the influence of focal interictal epileptic spikes on primary auditory cortex (PAC) was evaluated. Spontaneous cerebral magnetic fields and auditory evoked magnetic fields were recorded in 40 epileptic patients and 9 healthy volunteers using MEG and latency of N100m in the bilateral hemisphere, and the distribution of epileptic spike dipoles were measured. Depending on the presence of structural lesions and the localization of spike dipoles, the patients were divided into groups as follows: group I, patients with structural lesions in PAC; group II, patients without structural lesions and with spike dipoles in PAC; and group III, patients with neither structural lesions nor spike dipoles in PAC. Nine healthy volunteers were recruited and evaluated as control group. Compared with group III and the control group, N100m latencies in groups I and II were significantly delayed. A delay in N100m latency was found not only among patients with structural lesions in PAC, but also among patients demonstrating cluster of epileptic spike dipoles in PAC. This finding indicates that the presence of epileptic spikes may influence the mechanism of processing auditory information in PAC.
    Journal of Clinical Neurophysiology 07/2007; 24(3):263-70. · 1.45 Impact Factor