Yasuhiko Mochimatsu

Traumatic Intraventricular Hemorrhage: Report of Twenty-six Cases and Consideration of the Pathogenic Mechanism

A series of 26 patients suffering traumatic intraventricular hemorrhage (IVH) after closed head injury is reviewed, and the pathogenic mechanism of the traumatic IVH is discussed considering the site of origin of the IVH. Computed tomographic detection of the origin of the IVH was possible in 15 patients (Group 1): 6 had frontal or temporal contusional intracerebral hemorrhage spreading into the ventricle (Subgroup A), 5 had the original hemorrhage in the caudate nucleus (Subgroup B), and 4 originally bled in the thalamus (Subgroup C). The origin of the IVH was not determined in 11 patients (Group 2): 6 had concomitant hemorrhage around the brain stem (Subgroup D), and 5 had small IVH with or without small intracerebral hemorrhage (Subgroup E). The site of impact was not uniform in Subgroup A, whereas the other four subgroups usually had frontal or occipital impact. In Subgroup A, the IVH was discovered more than several hours after trauma. In the other four subgroups, however, the IVH was detected in as short a time as 0.5 to 1.5 hours after trauma. In Subgroups B and C, the impact along the long axis of the skull and the early occurrence of hemorrhage in the basal ganglia suggest that shear injury between the perforating vessels and the basal ganglia may be the responsible mechanism. The several other possible mechanisms in Subgroups D and E are reviewed and discussed in relation to diffuse brain injury.

Computed tomography of intracranial chondroma with emphasis on delayed contrast enhancement.

Intracranial chondroma is an unusual cartilaginous tumor originating from the base of the skull. We report on two cases of intracranial chondroma that showed delayed contrast enhancement on CT after high-dose administration of contrast medium. This CT feature may be useful to differentiate chondromas from other tumors of the skull base such as meningiomas and neurinomas.

Telecanthal Approach for Meningiomas in the Ethmoid and Sphenoid Sinuses

In three cases involving meningiomas in the ethmoid and sphenoid sinuses, transbasal spreading of the interocular distance (telecanthal approach) was used for tumor removal and reconstruction of the skull base. This telecanthal approach involves 1) bilateral en bloc removal of the superior lateral rim of the orbit, the nasal bone, and the posterior lateral wall of the orbit; 2) detachment of the medial canthal ligaments; and 3) spreading of the interocular distance. This approach provides a wide working space beneath the anterior half of the midline skull base, and needs neither a facial incision nor significant retraction of the brain. The surgical technique and its modification are described. The discussion focuses not only on comparisons with other techniques, but on the indications for this approach. Meningiomas originating in the paranasal sinuses are rare; a brief review of the literature concerning the clinicopathological features and pathogenesis is also given.