Mitsuo Tsuru

Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries.

SummaryIn a review of the vertebral angiograms of 300 patients free from disease at the craniovertebral junction, we found atlantoaxial arterial anomalies in 2,3%. These were: 2 cases in which the vertebral artery ran in the spinal canal below C1, 3 cases of duplication of the vertebral artery above and below C1, and 2 cases of origin of the posterior inferior cerebellar artery at C2. Although these arteries ran in the spinal canal between C1 and C2, they never encroached upon the posterior third of the canal. From the survey of another 21 patients having bony abnormalities at the craniovertebral junction, the first type of arterial anomaly described above was seen in 4 patients and associated with failure of segmentation of the embryonic sclerotome such as occipitalization of the atlas or Klippel-Feil syndrome. It is possible to relate the development of these anomalous vessels to malarrangement of the embryonic segmental arteries. Our results indicate that one must be cautious with lateral C1/2 puncture or surgical exposure of the region.

High Resolution Computed Tomography in the Diagnosis of Cervical Disc Disease

SummaryIn this study, the authors evaluate the importance of computed tomography (CT) in 15 patients who underwent surgical treatment for cervical disc disease. In nine operated on by an anterior approach, all CT examinations were interpreted as positive for disc herniation and correlated precisely with surgical observations. CT demonstrated protrusion of the disc, centrally in four and posterolaterally in five in all of whom disc material was found posterior to the vertebral body. Of six who underwent laminectomy, either thickening or calcification of the ligamentum flavum was demonstrated by CT and confirmed at surgery in five. Vacuum phenomenon in the intervertebral space and hypertrophy of the intervertebral joint were not infrequently associated. CT can exactly delineate cervical disc lesions and associated pathological changes.

Light scattering properties of a rough-ended optical fibre

Abstract Uniform wide-angle irradiation of a laser beam is achieved by roughening chemically the output end of an optical fibre. The angular distribution of the scattered light is analysed experimentally as a function of the incident angle of the laser beam into the input end of the fibre and the length of the rough core surface at its output end.

Functional prognosis of surgical treatment of craniosynostosis

Twenty-three cases of craniosynostosis were studied with regard to age at operation, symptoms, operative methods, and long-term results. Long-term results of 20 cases that were followed up for more than 1 year after surgery showed that mental retardation remained in 8 cases; a slight improvement in mental function was observed in only 2 cases. Of the 8 patients with mental retradation, 7 were operated on more than 6 months after birth, 7 showed striking digital impression on skull X-ray films and 5 were suffering from oxycephaly. Of the 8 patients with mental retardation, 5 had suffered from perinatal asphyxia or had seizures during delivery and subsequent past history. From these observations, factors affecting prognosis are: (1) age at operation; (2) the degree and duration of increased intracranial pressure; (3) the extent and degree of suture closures; (4) perinatal asphyxia and seizure disorders.

Effects of mild hypercapnia on somatosensory evoked potentials in experimental cerebral ischemia.

In a previous report, the authors demonstrated the effectiveness of mild hypercapnia inenhancing decreased perfusion flow in ischemic, non-infarcted brain tissues. However, the previous worklacked in verification of improvement of suppressed brain function. Therefore, this report was attempted toevaluate the effect of hypercapnia on somatosensory evoked potential (SEP), using the similar ischemicmodel as previously. The results showed that mild hypercapnia of 43 to 55 mm Hg range was beneficial notonly for enhancing decreased perfusion flow but also for restoring suppressed SEP. This report seems to bethe first publication which verifies a presence of correlation between local cortical blood flow (LCBF) andSEP under mild hypercapnia in mildly to moderately ischemic brain tissues. Stroke Vol 15, No 2, 1984

Computed tomographic findings of vacuum phenomenon in cervical intervertebral disks

A gaseous collection in the intervertebral space, or the vacuum phenomenon, was observed on computed tomograms in as many as 30% of the patients with cervical disk disease. The condition most frequently occurred at the level of C5-6. The gas tended to accumulate more often at the marginal region of the intervertebral disks, the level at which marked degeneration was seen; thus, it may be related to cracks within not only the nucleus pulposus, but also in the annulus fibrosus.

Site and Mechanism of Vascular Stenosis under Increased Intracranial Pressure — Intracranial Venous Pressure Regulation Mechanism

Although many authors have suggested vascular congestion of venous system under increased intracranial pressure as a cause of CBF reduction, the exact site and mechanism of compression has remained obscure. The results of our previous investigations in dogs are summarized in Fig. 1. Cortical venous pressure (CVP), bridging venous pressure (bridging VP), and lateral lacunar pressure (lat lacuna P) were constantly 4–18 mmHg higher than ICP, regardless of the level of ICP, while superior sagittal sinus pressure (SSSP) is quite stable at low levels (4–6 mmHg). Thus, pressure gradients between the cortical arterial pressure and the CVP, gradually decrease as ICP is elevated, while the pressure gradient between the CVP and the SSSP continuously increases as ICP is elevated. These evidences indicate that vascular stenosis is taking place in the lateral lacuna of superior sagittal sinus.

Catheter cervical vertebral venography

Cervical vertebral venography using catheterization via the femoral vein was carried out in 78 cases. In disc disease the internal vertebral venous plexus (IVVP) are interrupted at single or multiple levels, and sometimes completely blocked. In ossification of posterior longitudinal ligament, the IVVP are separated bilaterally and interrupted at multiple levels due to centrally situated ossification and associated osteophytes. Venography helps to determine the upper and lower limits of laminectomy, and the necessary sites of facetectomy. The IVVP in the thoracic region were clearly opacified in 86% of 37 normal selective azygograms.

Clinical Significance of TCP Measurements Following Intracranial Surgery

The present study was intended to find out correlations between clinical manifestations and the level and course of ICP following major intracranial surgery.

Hand-Schüller-Christian Disease in a Girl with Cerebellar Ataxia

A case of Hand-Schuller-Christian disease with involvement of the central nervous system is reported. The patient was a 13-year-old girl, admitted with cerebellar ataxia, polydipsia and polyuria, exophthalmos and visual impairment. Computerized tomography (CT) scan with contrast enhancement revealed a high-density mass at the left cerebellopontine angle, brachium pontis, cerebellar hemisphere, ambient cistern, superior cerebellar cistern, quadrigeminal cistern and posterior third ventricle. High-density masses along the bilateral optic nerves were also revealed. Left vertebral angiography showed no tumor stain. Suboccipital craniectomy was performed after the Steins approach, and the tumor which adhered strongly to the cerebellum was partially removed. The tumor was yellowish in color, fibrous, and elastic hard. Histological examination showed histiocytosis X. It was supposed from the clinical course that the disease began in the hypothalamic region and spread through the subarachnoid and Virchow-Robin spaces to the optic nerve sheath and posterior cranial fossa. Only twenty-five cases of Hand Schuller-Christian disease with cerebellar signs or cerebellar involvement have been reported in the literature. CT findings of Hand Schuller-Christian disease with cerebellar involvement has not been reported.