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Biomedical subjects

M Tsuru

Publications and source records attributed to M Tsuru.

At least 145 records · Page 8Linked to original sources
PubMed1976

[Atlanto-axial dislocation--instability index and indications for surgery (author's transl)].

Thirty cases of atlanto-axial dislocation were investigated and the results are reported. The may be divided into 2 groups; (a) 15 cases of abnormalities of the odontoid process, i. e. 7 cases of os odontoideum, 7 cases of fractured odontoid, 1 cases of deformed odontoid, and (b) 15 cases with no abnormalities of the odontoid process. Neurological signs were noted in 14 cases which may be divided into the following three types, i.e. acute, recurrent, and chronic-progressive. The spinal canal diameter at the atlanto-axial level was measured in the position of flexion and extension using cervical tomography. The degree of motility thus obtained was expressed in terms of "Instability Index" (I. I.) devised in our clinic. In the group with neurological signs, the acute type showed an I. I. of 39 percent which was the highest value, and followed by 33 percent in the recurrent type. In the chronic-progressive type, the I. I. value was as low as 3.75 percent with a mean maximal diameter of 11.0 mm. Operation was performed in 16 cases. In 12 cases, posterior fusion was performed from the occipital bone to C3 or in some cases C4. In 3 cases, posterior decompression and fusion from the occipital bone to C3 were conducted. In one case, anterior decompression and fusion was performed by the transoral approach. The outcome was generally satisfactory. As a new method of posterior fusion, we have used "single bone-flap" method since 1972, that could fix the occipital bone and the cervical spines more tightly. In conclusion, the operation is indicated in the following cases; (1) when neurological signs are evident, (2) even in the abcence of neurological signs, (a) when the I. I. is high (over 20 percent), (b) even when the I. I. is low, when the maximal diameter of the canal is under 14.0 mm.

Adolescent↗
PubMed1976

[Six cases of hydroencephalodysplasia (author's transl)].

Six cases of hydroencephalodysplasia were evaluated from the points of clinical signs and symptoms and neuroradiological procedures and diagnostic problems were discussed. All of our cases were characterized by extensive dysplasia of the brain and increased cerebrospinal fluid pressure. Deformity of the head and developmental arrest of the psychomotor function were observed in five cases. The side of the skull deformity was consisted with that of the brain defect. Pneumoencephalography and cerebral angiography are characteristic in this disease, but these procedures have to be carried out with caution in case of poor general condition. Transillumination and brain scan are also useful procedures and RI-cisternography is important for indication of shunting operation. Early rehabilitation for the motor dys function is main therapeutic trial, though the cases with increased intracranial pressure require cerebrospinal fluid shunt.

Agenesis of Corpus Callosum↗
PubMed1976

[The antero-posterior diameter of the cervical spinal canal in cervical spondylosis (author's transl)].

1. The antero-posterior diameter (APD) of the cervical spinal canals in 96 healthy adults, 108 cases of radiological cervical spondylosis (asymptomatic) and 96 cases of cervical spondylosis with radiculopathy or radiculomyelopathy was measured for each vertebra by the method of Burrows. (Filmfocus distance was 1.2m). 2. The APD in patients with symptomatic spondylosis was found to be significantly narrower than those of without. 3. Since the upper limit of APD at C4 to C6 vertebrae in symptomatic spondylosis was 16 mm, while the lower limit of APD in asymtomatic spondylosis was 14 mm, the following conclusion appears justified. 1) When the APD is narrower than 16 mm, the osteophytes along the posterior border of the spinal bodies or degenerative disc protrusions may produce cervical radiculomyelopathy, although the cord and the roots may escape from compression by the spondylotic changes even when the APD is wider than 14 mm. 2) When the APD is narrower than 13 mm, it is almost always certain that the osteophytes or herniated discs compress the cervical cord and roots.

Adult↗
PubMed1976

[A case of intramedullary spinal schwanoma (author's transl)].

A rare case of intramedullary schwannoma of the spinal cord has been reported, The patient was a 30-year-old woman, who began to notice weakness in her right leg approximately 6 months prior to admission, followed 4 months later by numbness and weakness of the right arm. The above symptoms were progressively getting worse, and she was admitted to Hokkaido University Hospital on February 23, 1974. Neurological examination revealed slow speech, bilateral horizontal nystagmus, absent gag reflex and weakness of right trapezius muscle. Spasticity was noted in 4 extremities, in addition to right hemiparesis. All deep tendon reflexes were hyperactive, right more than left, with bilateral Hoffmann's and Babinski's signs. Vibration sense was diminished below the level of bilateral iliac crests. A tumor around the foramen magnum was suspected, however plain skull and neck, laminogram of cervical spines, vertebral arteriogram, fractional pneumoencephalogram and myodil myelogram failed to disclose abnormalities. Manometric Queckenstedt test showed a partial block on flexion, with CSF protein of 56 mg/dl. Air myelogram clearly visualized the presence of an intramedullary tumor at the level of the medullo-spinal junction. Subtotal removal of the intramedullary tumor at C1 was performed, which proved to be a schwannoma histologically. 14 such cases are reported in the literature and summarized on Table I, including our case. Clinical features of tumors around the foramen magnum are fairly complexed, and some radiological examinations might not be conclusive. It is stressed that air myelogram is extremely valuable in the diagnosis of lesions around the foramen magnum.

Adult↗
PubMed1975

[Circulatory disturbance of the venous system under intracranial hypertension (3rd report)-an experiment using primates (author's transl)].

Although many authors suggested vascular compression of venous system under increased intracranial pressure, the exact site and mechanism of the compression are still obscure. By the previous reports obtained in mongrel dogs, we clarified that a vascular stenosis took place 1-2 mm lateral to the junction between the lateral lacuna and the superior sagittal sinus as the intracranial pressure (ICP) was elevated. The present study was designed to reinvestigate the internal pressure of the intracranial venous pathways using crab-eating monkeys under gradually increasing ICP. (1) METHODS: Using crab-eating monkeys, pressure of the cortical veins and the superior sagittal sinus was measured by cannulating small calibred (0.4 - 0.5 mm in outer diameter) polyethylene tube. The ICP was elevated by inflating rubber balloon placed in the epidural space. Pressure of the above mentioned vessels, systemic blood pressure and ICP were measured with a standard pressure transducer. Pressure gradient between the lateral lacuna and the superior sagittal sinus was measured by moving to and fro the tip of small calibred tube which was inserted into the lacuna under operation microscope. (2) RESULTS: The pressure of the cortical vein was constantly 50 - 250 mmH2O (4-18 mmHg) higher than the ICP in monkeys, regardless of the level of ICP (Fig. 1, 2 & 3). Pressure of the superior sagittal sinus was quite stable at the low level untill the ICP was elevated up to 500mmH2O (36 mmHg) and more or less increased thereafter (Fig. 1 & 2). The pressure in the parasagittal venous pathways presented abrupt alterations between the lacuna and the superior sagittal sinus in monkeys (Fig. 6). (3) CONCLUSIONS: It was concluded that a gradual stenosis of parasagittal venous pathways took place 1-2 mm lateral to the junction between the lateral lacuna and the superior sagittal sinus in monkeys when the ICP was gradually elevated. This result suggests that also in humans a gradual stenosis occurs in a similar fasion as the ICP is elevated. The results of the experiment obtained in monkeys were almost the same as those previously obtained in dogs.

Animals↗
PubMed1975

[The rapid microscopical diagnosis of brain and spinal cord tumors by cryostat-cut frozen section (author's transl)].

The rapid histological diagnosis of neurosurgical biopsy material is of prime importance for the neurosurgeon. Cryostat-cut sections of fresh frozen tissues have been used in our department. The surgical materials are rapidly frozen at - 150 degrees C, and serial sections, 10 microns thick, are cut in a cryostat at -18 degrees to -20 degrees C. The sections are adhered to cover glasses and stained with Metachrome solution (a mixture of 1% Azure A and 0.5% Erie Garnet B). The rapid and accurate diagnosis can be obtained within 5 minutes. The advantage of cryostat-cut frozen section is the preservation of cell density and tissue architecture, which is most important in the diagnosis of neurosurgical materials, especially in case of diffusely infiltrating glioma. The previously reported methods, such as smear technique and frozen sections by using freezing microtome are also reviewed and discussed.

Brain Neoplasms↗