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Lateral wall paraclinoid aneurysms (LPA) are a rare type of aneurysm located on the lesser curve side of the internal carotid artery (ICA) bend, at the level of the anterior clinoid process. The objective of this study was to assess the influence of flexion of the ICA on the morphology of aneurysms and outcome of endovascular treatment. Between 2003 and 2018, we treated 643 cases of unruptured paraclinoid aneurysms with endovascular therapy in our institution. Of those cases, aneurysms projecting laterally on preoperative angiography were defined as LPA. The degree of bending of the ICA (ICA angle) was measured and statistically analyzed in relation to the aneurysm characteristics and the occlusion status after treatment. In all, 43 aneurysms were identified. ICA angle was positively correlated with the maximum dome size of the aneurysm (P

A 70-year-old man, who had previously undergone surgical resection of left parasagittal meningioma involving the middle third of the superior sagittal sinus (SSS) two times, presented with recurrence of the tumor. We performed removal of the tumor combined with SSS resection as Simpson grade II. After tumor removal, since a left dominant bilateral chronic subdural hematoma (CSDH) appeared, it was treated by burr hole surgery. However, because the CSDH rapidly and repeatedly recurred and eventually changed to acute subdural hematoma, elimination of the hematoma with craniotomy was accomplished. The patient unfortunately died of worsening of general condition despite aggressive treatment. Histopathology of brain autopsy showed invasion of anaplastic meningioma cells spreading to the whole outer membrane of the subdural hematoma. Subdural hematoma is less commonly associated with meningioma. Our case indicates the possibility that subdural hematoma associated with meningioma is formed by a different mechanism from those reported previously.

A 33-year-old male became aware of a painless soft mass in the left occipital region. His medical and family history were unremarkable for neurofibromatosis type 1 (NF1) or other genetic disorders. Physical examination showed no signs of NF1. Neurological and ophthalmological examinations found no abnormality. Cranial computed tomography showed an isodense mass located subcutaneously with irregular deformities in the adjacent occipital bone. Magnetic resonance (MR) imaging demonstrated that the lesion, 7.5 × 5.5 cm in diameter, was hypointense both on T1- and T2-weighted images and intensely enhanced after gadolinium infusion. The patient requested to remove the large mass. The subcutaneous tumor was well circumscribed, encapsulated, and less vascular, and resected en bloc. The histological diagnosis was neurofibroma without findings of cell atypia, whereas genomic exploration identified abnormal gains in NF1 gene, and resultant absence of neurofibromin, a protein coded on NF1 gene. Solitary neurofibromas in “clinically” non-NF1 patients may originate from the genomic changes in NF1 gene.

Drawing of metal wire has been conducted using a hole die, in which the integrity of hole is very important to warrant the quality of wire. Lapping of inner wall of the hole has been performed usually with hand-finishing using a bar daubed the paste kneaded the diamond powder. Hand working, however, needs long time to finish the hole. High speed flow finishing method developed recently, seems to have an excellent performance of the polishing of the hole die. Setup of the hole die finishing has newly developed. It is found that the surface roughness of inner wall of the hole decreases with the slurry flow passes, but that finishing time is very short. Experiments show that the flow finishing yields the smoothed surface and desirable shape of the hole.

Purpose To investigate the length variation of the posterior auricular artery and propose a novel classification of the posterior auricular artery based on angiographical appearance. Patients and Methods A series of 234 consecutive patients who had undergone conventional cerebral angiography was analyzed. The posterior auricular artery was examined on the lateral projection of the external carotid or common carotid arteriography. The posterior auricular artery was classified into four groups by length, using the external auditory canal and the top of the helix as radiographical landmarks. Our proposed classification is as follows: Type A, posterior auricular artery terminates between its origin and the center of the external auditory canal; Type B, posterior auricular artery terminates between the center of the external auditory canal and the top of the helix; Type C, posterior auricular artery terminates between the top of the helix and the vertex; and Type D, posterior auricular artery reaches up to the vertex. Results A total of 424 (right, 214; left, 210) posterior auricular arteries were analyzed in 111 men and 123 women aged 11 to 91 years (mean, 61.0 years) examined for aneurysms in 78 cases, occlusive vascular diseases in 56, intracranial hemorrhages in 41, tumors in 35, and others in 24. Types A, B, C, and D were found in 15.1%, 34.9%, 48.8%, and 1.2% of the patients, respectively. Conclusion A novel classification of the posterior auricular artery identifies four types based on its length on cerebral angiography.