PubMed Health⌕ Search

Biomedical subjects

Y Nagaseki

Publications and source records attributed to Y Nagaseki.

5 recordsLinked to original sources
PubMed1992

Oblique sagittal magnetic resonance imaging visualizing vascular compression of the trigeminal or facial nerve.

An oblique sagittal magnetic resonance (MR) imaging method was developed to provide better visualization of vascular compression of nerves. The MR images of 12 patients with trigeminal neuralgia and 24 with hemifacial spasm were analyzed. The oblique sagittal views were obtained along the nerve identified by the axial view at an angle of 105 degrees between the line along the dorsal brain stem and the line along the margin of the pontomedullary junction (in patients with hemifacial spasm) or by the midsagittal view through the midpons (in patients with trigeminal neuralgia). The T1- and T2-weighted, proton-density, and/or gradient-echo MR images were evaluated to optimize imaging conditions. The oblique sagittal gradient-echo MR image most clearly visualized vascular compression of the nerves as high-intensity lines in six patients with trigeminal neuralgia, which was confirmed intraoperatively in four. Fifteen (75%) of 20 oblique sagittal gradient-echo MR images demonstrated vascular compression of the facial nerves in patients with hemifacial spasm; 12 of these were confirmed intraoperatively. The control study used 15 oblique sagittal gradient-echo MR images of nonaffected contralateral and normal sites. Four false-positive findings were found. Oblique sagittal gradient-echo MR images are a useful planning aid, allowing differential diagnosis prior to microvascular decompression in trigeminal neuralgia and hemifacial spasm.

Adult↗
PubMed1991

[Superior sagittal sinus thrombosis complicated with multiple aneurysms presenting as subarachnoid hemorrhage. Case report].

A 48-year-old female suffered from severe headache, vomiting, and disturbance of consciousness. On admission, she was somnolent with mild paresis of the left leg. Precontrast computed tomography (CT) scans showed a high-density area in the left sylvian fissure and the posterior horn of the left lateral ventricle. Angiographically, a right middle cerebral artery aneurysm and a basilar artery aneurysm were recognized. Furthermore, on the venous phase of bilateral carotid angiograms, superior sagittal sinus (SSS) thrombosis was recognized. Subarachnoid hemorrhage (SAH) was probably induced by rupture of a dilated vein associated with SSS thrombosis, because high-density area on CT scan and location of the aneurysms were different. The patient was initially treated conservatively. Two months later, craniotomy was performed which did not disclose any trace of hemorrhage around the aneurysms and aneurysms themselves. Postoperatively, acute brain swelling and generalized convulsion were induced. The patient became ambulatory 5 months after surgery. In SAH cases, the venous phase should be examined at least in one side of the carotid arteries. In such a SAH case induced by venous thrombosis complicated by aneurysms it is very difficult to decide the timing of surgery for aneurysms.

Cerebral Angiography↗
PubMed1989

Primary internal ophthalmoplegia due to head injury.

Six cases of internal ophthalmoplegia due to direct head injury are presented. All six patients had a dilated, nonreactive pupil. Four had no extraocular palsies or ptosis and two had partial extraocular palsies or ptosis. Disturbance of consciousness was absent or very mild, and all patients fully recovered within 1 to 7 days after the traumatic event. No patient had a history that suggested a cause for oculomotor nerve palsy, and emergency CTscans showed no mass lesions. The internal ophthalmoplegia was recognized immediately after trauma. Although minimal oculomotor nerve palsies due to unruptured intracranial aneurysms have been described, none of our patients complained of periorbital or retroorbital pain either before or after the trauma, which rules out intracranial aneurysms as the cause of the internal ophthalmoplegia. Therefore, we concluded that the internal ophthalmoplegia was due to direct head injury. The pathophysiological mechanism of the internal ophthalmoplegia appeared to be slight injury of the pupillomotor fibres on the ventromedial surface of the third nerve at the posterior petroclinoid ligament, which acted as the fulcrum due to the downward displacement of the brainstem at the time of impact.

Adult↗
PubMed1989

Cytometric analysis of the thalamic ventralis intermedius nucleus in humans.

1. The cytoarchitecture and the exact borders of the thalamic ventralis intermedius (Vim) nucleus of humans as originally delineated by Hassler (17) have been studied on the basis of stereotaxic coordinates correlated with Nissl- and Golgi-impregnated sections, using a microscopic image analyzer. 2. The Vim nucleus forms part of a relatively "cell-sparse zone" which includes the other ventrolateral thalamic subnuclei. It is distinguished by the presence of darkly stained, large and medium sized, angular cells with areas of approximately 500-1,000 microns 2 and 300-400 microns 2, respectively, and a cell density of approximately 50-90 (mean 65)/mm2 in 50-microns-thick sections. 3. Both sets of neurons have the characteristics of thalamocortical relay neurons in Golgi preparations. Large neurons have rectangular or square somata 30-50 microns diam and are concentrated mainly in the lateral and ventral two-thirds of the nucleus. The medium neurons have square to round somata, 15-25 microns diam, and are distributed homogeneously through the nucleus. The total dendritic arborization of both types is usually symmetrical in all directions and at least 500-600 microns diam. 4. The borders between the Vim nucleus and the Nucleus ventrooralis (Vo) and between the Vim nucleus and the Nucleus ventrocaudalis internus (Vci) are clearly identified by clearcut differences in cell size and cell density. The borders between the Vim nucleus and the Nucleus ventrooralis internus (Voi) and between the Vim nucleus and the Nucleus zentrolateralis intermedius (Zim) are quite obscure, and these nuclei, with Vim, seem to be parts of the large cell sparse zone comparable to that described in monkeys as VLp or VL. The border between the Vim nucleus and the Nucleus ventrocaudalis externus anterior (Vcea) is also unclear but the increased cell density and intermingling of small and medium-to-small neurons with large neurons are the major features that distinguish the Vcea nucleus from the Vim nucleus cytometrically. 5. The position and anatomic organization of the human Vim nucleus make it likely that it is the region in which kinesthetic response were recorded in the accompanying paper but extension of the recording sites into the Vcea nucleus cannot be ruled out.

Aged↗