Norio Sunami

Agenesis of the left internal carotid artery, common carotid artery, and main trunk of the external carotid artery associated with multiple cerebral aneurysms

A case of agenesis of the left internal carotid artery, common carotid artery, and the main trunk of the external carotid artery with multiple cerebral aneurysms is presented. This case was diagnosed by angiography and computed tomography scanning and confirmed by operation. Correlation between the anomaly of the circle of Willis based on the absence of the internal carotid artery and the development of cerebral aneurysm is discussed on the basis of the reported cases.

Histopathologic investigation of a case of meningioangiomatosis not associated with von Recklinghausen's disease

A case of meningioangiomatosis not associated with von Recklinghausens disease is reported. Microscopically, irregularly branched blood vessels extending into the gray matter from the meningeal surface are surrounded by a concentric arrangement of proliferating spindle-formed cells. Ultrastructurally these proliferating cells are composed of elongated heterochromatin-rich nuclei and slender cytoplasm-containing microfilaments, occasionally associated with desmosomal junctions and basal laminalike structures. Judging from these findings, together with a negative immune reaction for S-100 protein, the histogenesis of these proliferating cells is most probably meningothelial in origin.

Serial observations of brain stem function by auditory brain stem responses in central transtentorial herniation

Changes in auditory brain stem responses were serially investigated in a patient with downward transtentorial herniation due to acute obstructive hydrocephalus to correlate the neurological signs with the results of computerized tomography. Neurological deterioration correlated highly with disruption of auditory brain stem responses, especially with that of the components of waves V to VII. A noninvasive technique, the measurement of auditory brain stem responses is thought to be useful in detecting the severity of downward transtentorial herniation and in estimating the recovery of brain stem function after surgical treatment of intracranial hypertension.

Craniopharyngioma in the third ventricle: necropsy findings and histogenesis.

A case of craniopharyngioma confined within the third ventricle with necropsy is reported. A stalk-like structure in this tumour was present in the wall of the third ventricle at its base. It is suggested that this tumour might have arisen from the remnants of Rathkes pouch persisting in the tuber cinereum.

Computed angiotomography of unruptured cerebral aneurysms.

Twenty-seven unruptured cerebral aneurysms in 25 patients were detected by computed angiotomography. A comparison of the computed angiotomographic features in common aneurysm sites with plain CT and conventional arteriography was carried out. An isodense, round cisternal defect and a calcification or high-density mass in the basal cisterns on plain CT are important findings suggestive of unruptured aneurysms larger than 7 mm in diameter. The identification of the aneurysm, as well as of the afferent and efferent arteries on computed angiotomography is essential for the direct diagnosis of smaller unruptured aneurysms related to the circle of Willis. This is possible in a number of cases when the aneurysms are relatively large. It appears that the aneurysm size must be larger than 3 mm in diameter to permit its recognition on the basis of angiotomography and the avoidance of false-positive findings.

Primitive Neuroectodermal Tumor with Peritoneal Metastasis through a Ventriculoperitoneal Shunt

A 13-month-old boy admitted with lethargy and hydrocephalus was found to have a right thalamic mass. Ventricular drainage was instituted, and the tumor mass was reduced by partial resection and local irradiation. A ventriculoperitoneal shunt was then placed. However, the tumor recurred 16 months later, with extensive ventricular seeding and peritoneal metastasis through the shunt tube. The child died 22 months after onset. Histological study of surgical specimens of the primary tumor and autopsy specimens of the brain and peritoneal metastatic tumors revealed poorly differentiated, small, round cells with numerous mitotic figures. In addition, autopsy specimens of the brain tumor contained areas of ependymal, oligodendroblastic, and spongioblastic differentiation. On immunohistochemical study, the tumor cells of each specimen were positive for anti-neuron specific enolase and anti-neurofilament antibodies, but negative for anti-glial fibrillary acidic protein antibodies. Electron microscopy revealed some zonulae adherens. These findings strongly suggest that the tumor originated from primitive multipotential cells capable of differentiating into ependymal, glial, and neuronal lines.

Screening and treatment of unruptured cerebral aneurysms

Thirty outpatients with unruptured cerebral aneurysms screened by computed angiotomography have been analysed and followed up in our clinic since 1979. Seventeen were men and the age range was 41 to 74 years old (mean 57.7 years). Patients had no or only mild neurological symptoms, such as headache, sensorimotor or speech impairment and others, which were scarcely related to the unruptured aneurysms themselves. It is important to realize that these first aneurysms which remain unruptured, have a primary significance to the individual in the protective aspect of an initial subarachnoid haemorrhage. Operation was successfully performed in fifteen patients. Transient aggravation of previous diseases, e.g. cerebral infarction, occurred in three after operation. Follow-up studies of fifteen patients without operation revealed no change in eight and some worsening or death due to other or previous diseases in six. One died of aneurysmal rupture in the 5th month after its detection. Because of the low operative risk, we advocate the operative treatment of unruptured aneurysms, following careful selection of the indicated patients.

Serial Observations of Brain Stem Function in Acute Intracranial Hypertension by Auditory Brain Stem Responses — A Clinical Study

Recently, multimodality evoked potentials have been used for the evaluation of brain function in patients with severe head injury and acute intracranial hypertension. We have studied the changes in brain stem function in patients with acute intracranial hypertension without any pressure difference between the supra- and infratentorial space and with central and uncal herniation, by measuring the auditory brain stem responses (BERs) that reflect the functional and structural integrity of the brain stem auditory pathway.

Changes in Local Blood Flow of the Brain Stem in Acute Intracranial Hypertension — An Experimental Study

In patients with supratentorial space-occupying lesions, dysfunction of the brain stem secondary to ischemia and distortion is the most important factor for their morbidity and mortality. This study has been carried out to evaluate the effect of supratentorial mass lesions on the local cerebral blood flow (1-CBF) of the brain stem with special reference to the following three points.

Management of asymptomatic unruptured aneurysms-Prospective analysis of the cases without operation.

This analysis indicates the results of a prospective study of 102 patients with 124 asymptomatic unruptured aneurysms without operation from 1993. The patients (M: 33, F: 69) were followed from 2 to 83 months (mean 38.2). The ages at diagnosis ranged from 21 to 78 years (mean 64.1) The locations were ICA: 48, MCA: 37, AcomA: 23, the vertebrobasilar artery: 9, ACA: 6 and PCA: 1. The average aneurysmal diameter was 4.3 mm, a range of 2 to 12 mm. They were followed up radiologically using MRA, MRI and 3D-CT angiography. Among the 102 patients, five had suffered subarachnoid hemorrhage (SAH) due to rupture of the aneurysms (MCA: 3, BA-SCA: 1, IC-PC: 1) The maximal diameter of the aneurysms at diagnosis ranged from 4.5 to 8 mm. The period from discovery to SAH was from 4 to 69 months and the cumulative rate of rupture of the aneurysms was 1.5 percent per year. The present study demonstrates that five asymptomatic unruptured aneurysms less than 10 mm in diameter subsequently ruptured. We ought to consider the data that unrup-tured aneurysms less than 10 mm in diameter have a very low probability of subsequent rupture published the New England Journal of Medicine (1998) very seriously.