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Biomedical subjects

I Koyanagi

Publications and source records attributed to I Koyanagi.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Anterior approach for cervical dumb-bell typed neurinomas].

We experienced three cases of the dumb-bell typed cervical neurinoma. All of them compressed the spinal cord in the spinal canal, and had developed through the intervertebral foramen and compressed and displaced the vertebral artery. The decompression of the vertebral artery and reconstruction of the spine as well as the removal of the tumor were thought to be important. We used the anterior approach and were able to operate safely and completely. The anterior approach was thought to be effective for the surgical treatment of dumb-bell typed cervical neurinoma.

Adult↗
PubMed1991

[A case of what was regarded as isolated benign cerebral vasculitis].

A 55-year-old man came to us with dysarthria and right hemiparesis. The cerebral angiography showed segmental narrowing and irregularity of the left anterior cerebral artery. The patient responded well to corticosteroid therapy and there was later angiographic evidence of healing. After systemic angiitis and central nervous system infection were excluded, the diagnosis of isolated benign cerebral vasculitis was made. According to past reports, at least 13 patients have been described as having isolated benign cerebral vasculitis. The common features of isolated benign cerebral vasculitis are as follows: 1) benign evolution, 2) sensitiveness to corticosteroids, 3) absence or minimal change of CSF findings, 4) angiographic pattern of arteritis, 5) the most common symptom is headache. We suggest that early corticosteroid therapy is necessary in any case of cerebral vasculitis.

Administration, Oral↗
PubMed1991

[Magnetic resonance imaging of posttraumatic syringomyelia and its surgical treatment].

Posttraumatic syringomyelia is an uncommon but significant late complication of spinal cord injury. It occurs in approximately 1.1 - 3.2% of cases of spinal injuries. With the increasing availability of CT and magnetic resonance imaging (MRI), the incidence of posttraumatic syringomyelia is increasing. The purpose of this report is to show MRI of posttraumatic syringomyelia and to assess the results of surgical treatment. Materials and Methods This series included 16 cases of posttraumatic syringomyelia studied with MRI. 9 out of 16 cases showed delayed deterioration of neurological symptoms following spinal injuries. The interval between the trauma and the delayed symptoms of deterioration was from 2 years 2 months to 32 years (mean, 8 years and 5 months). There were 13 men and 3 women. The age ranged from 22 to 69 years, with a mean age of 42 years. The initial spinal cord injury was located in the lower cervical region in 4 cases, the thoracic region in 8, and the upper lumbar region in 4. All the patients were studied with resistive 0.15T system (Toshiba MRT 15 A) or a superconductive 0.5T system (Toshiba MRT 50 A) or a superconductive 1.5T system (GE Sigma or Siemens Magnetom). Six patients underwent 8 operative procedures for posttraumatic syringomyelia. Syringoperitoneal shunt was performed in 4 patients, syringosubarachnoid shunt in 3 and ventriculoperitoneal shunt in one. Results 1. MRI In all cases, the posttraumatic syringomyelia was easily diagnosed by MRI. The syrinx extended superiorly and/or inferiorly from the area of the old trauma. In 4 out of 16 cases, the syrinx extended into the medulla oblongata.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Diagnosis and surgical treatment of spinal hemangioblastoma].

Spinal hemangioblastoma is a rare tumor. Its incidence varies from 1.6 to 2.1% of primary spinal cord tumors. In this report, the authors described MRI (magnetic resonance imaging) of spinal hemangioblastoma and its surgical results. [MATERIALS AND METHODS] This series included 10 spinal hemangioblastomas studied with CT or MRI. There were 8 men and 2 women. The age ranged from 21 to 68 years, with a mean age of 45 years. 6 patients were preoperatively and postoperatively studied with a resistive 0.15 T system (Toshiba MRT 15A) or a superconductive 1.5 T system (GE Signa or Siemens Magnetom). The lesions were single in 8 out of 10 patients and multiple in 2. 10 spinal hemangioblastomas were located in intramedullary space and 2 in both intramedullary and extramedullary space. 8 out of 10 patients (80%) were associated with cyst. [RESULTS] (1) MRI In T1-weighted MR images after administration of Gd-DTPA, the solid component of the tumor enhanced brilliantly. The enhanced lesions contained serpiginous areas of signal void, reflecting vascular structures in 5 out of 6 cases. The intrinsic spinal cord signal was heterogenous with low intensity areas representing the associated cyst. The cyst appeared either isointensive to cerebrospinal fluid (CSF) or hyperintense relative to CSF and slightly hypointense relative to the spinal cord. The precise delineation of the tumor was impossible without enhancement. Noncontrast T1-weighted MR images displayed diffuse widening of the spinal cord. On T2-weighted MR images, all regions of the spinal cord enlargement increased in signal. (2) Postoperative results All 10 cases of spinal hemangioblastomas were totally removed with good postoperative results and the associated cysts were drained. The postoperative MRI showed the disappearance of the tumor and significant reduction in the size of the cyst. [CONCLUSION] (1) Gd-DTPA enhanced MRI was useful in defining and outlining the solid component of spinal hemangioblastoma. (2) The complete removal of the tumor with only drainage of the cyst was possible with good postoperative results.

Adult↗
PubMed1990

[Anterolateral approach to giant cell tumor in T4 vertebral body].

A case of giant cell tumor involving the Th4 vertebral body is reported. A 27-year-old man, who had a 2 month history of back pain and paraparesis, was admitted to our department in August, 1986. On the first admission, he manifested severe paraparesis and sensory disturbance below the Th5 dermatome level. Neuroradiological examination demonstrated an epidural tumor involving the Th4 vertebral body and compressing the spinal cord. Emergency laminectomy for decompression and biopsy was performed. The surgical specimen was a giant-cell tumor. 6 weeks after the first operation, total removal of the tumor and anterior fusion of the Th 3-5 with iliac bone graft was performed through the anterolateral transthoracic approach. Postoperative course was uneventful. A curative resection and immediate stabilization was thus able to be undertaken through the anterolateral transthoracic approach, when the epidural tumor was confined to the thoracic vertebral body.

Adult↗
PubMed1990

[Clinical reference values for laboratory hematology tests calculated using the iterative truncation method with correction: Part 1. Reference values for erythrocyte count, hemoglobin quantity, hematocrit and other erythrocyte parameters including MCV, MCH, MCHC and RDW].

Age and sex dependent differences in the clinical reference values for erythrocyte count (RBC), hemoglobin quantity (Hb), hematocrit (Ht) and other erythrocyte parameters including MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), MCHC (mean corpuscular hemoglobin concentration) and RDW (red cell distribution width), were calculated by the iterative truncation method with correction (Usui's method) using the results from tests on 6,300 patients' specimens obtained at Kyoto University Hospital. For RBC, Hb and Ht, the data obtained from the individuals below 13 years old showed the normal or sometimes log-normal distribution, but adjustment by the Xn-type variable transformation was often necessary to obtain the normal distribution for the data taken from the populations containing individuals over the age of 14. For the clinical reference values of RBC, Hb and Ht, no sex difference was observed below the age of 12. The values for males were significantly higher than those of females in the age range 13-79, and the values showed no significant sex-dependent difference at ages above 80. In females, age-dependent change of values for RBC, Hb and Ht was less prominent than in males; especially the upper limit values for females were very stable for all ages. MCV and MCH gradually increased with age both in males and females, and the MCHC remained constant in all age populations of male and female. The reference value for RDW was generated by the percentile method instead of the iterative truncation method because of the strong deviation in the distribution pattern, and the RDW values showed a gradual increase with age in both males and females.

Age Factors↗
PubMed1989

Significance of spinal cord swelling in the prognosis of acute cervical spinal cord injury.

Seven cases of acute cervical cord injury examined by CT-myelography are reported. Cord swelling was observed in 2 patients who developed complete lesions. Another 5 cases had an incomplete lesions. Spinal cord swelling indicated severe cord damage. External decompression seemed to have little effect on cord swelling. When cord swelling is absent, neurological improvement was expected though the initial neurological state showed severe deficits. A further 4 patients who had an acute cervical cord injury who were treated by myelotomy at the injury site are also reported. Two patients obtained significant improvement in upper limb function. The presence or absence of cord swelling as shown by CT-myelography is important for diagnosing the severity of cord damage. Myelotomy in the immediate post-accident period may relieve the effects of cord swelling.

Acute Disease↗
PubMed1989

Magnetic resonance imaging in cases of spinal dural arteriovenous malformation.

Two patients with spinal dural arteriovenous malformations associated with intramedullary changes confirmed by the T2-weighted magnetic resonance imaging (MRI) scans are reported. The characteristics of the MRI findings for these 2 patients were as follows. 1) In the T2-weighted spin-echo image, intramedullary changes observed by MRI were visualized as a high signal intensity area at the level where delay in venous circulation of the spinal cord was revealed by the angiography of the spinal cord. 2) After the obliteration of the arteriovenous shunt by surgical management, intramedullary changes remarkably decreased and disappeared with the disappearance of swelling of the spinal cord observed preoperatively. After that, the atrophy of the spinal cord was shown. 3) The level, extent, and severity of intramedullary changes were decided by the condition of the level where the radiculospinal vein, as the flowing vein, refluxes into the coronal venous plexus and venous flow occurs through the radiculospinal vein into the epidural veins. We suspect that intramedullary changes shown by the T2-weighted MRI scan chiefly represent edema of the spinal cord, caused by an increase in venous pressure due to venous congestion of the spinal cord. MRI is a very useful diagnostic aid to detect intramedullary changes associated with a spinal dural arteriovenous malformation and to evaluate therapeutic results after surgery.

Angiography↗
PubMed1989

[Myelotomy for acute cervical cord injury. Report of four cases].

Four cases of acute cervical cord injury treated by posterior midline myelotomy are described. The initial neurological examinations of these four patients indicated complete cord lesions. On plain neck X-rays, two exhibited anterior dislocation and two showed no bony injury other than ossification of the posterior longitudinal ligament. Myelography via C1/2 lateral puncture showed complete block of the subarachnoid space in two cases, and incomplete block in the other two. Computed tomographic myelography revealed cord swelling in all cases. Posterior midline myelotomy was performed after administration of a steroid and mannitol, or reduction of spinal dislocation. The time from injury to myelotomy ranged from 5 to 21 hours. No patient developed new deficits postoperatively. During long-term follow-up, which ranged from 10 to 19 months, all patients showed improvement in motor function of the upper extremities. Sensory disturbances also diminished to some degree. However, in one patient, who underwent myelotomy 18 hours after injury and had shown progressive neurological deterioration before surgery, the improvement in motor function was only slight. In this case, earlier myelotomy may have been more beneficial. These results support the indication for myelotomy in cases of acute cervical cord injury with cord swelling. Particularly if performed early, this procedure is effective in preventing secondary neurological damage.

Acute Disease↗
PubMed1988

[Spinal intramedullary tumor with exophytic growth].

We experienced 22 cases of spinal intramedullary tumor, in which 5 cases were accompanied with exophytic growth. We discussed their clinical and radiological features, and therapeutic problems. Concerning the locations of tumors with exophytic growth, the most common site was conus medullaris, accounting for 60% (3 cases). Histopathological findings were astrocytoma in two cases, and in one case, mixed glioma, ependymoma and hemangioblastoma. In neurological observation, the most common initial symptom was back pain and lumbago, suggesting root pain. No neurological features distinguishable from those of extramedullary tumors were presented. In radiological examination, myelography and CT myelography were very helpful for diagnosis. Myelography and CT myelography showed extramedullary mass, shift and deformity of spinal cord that was not serious as compared with the size of extramedullary mass, and showed the portion where the spinal cord was swollen. Good outcomes were obtained in a case with total removal, and two cases with subtotal and partial removal that were managed with additional irradiation and chemotherapy. However recurrence and intracranial seeding made prognosis poor in two cases where total removal was impossible. We thought that postoperative careful follow-up was necessary not only to detect recurrence but also to detect intracranial seeding in the cases of spinal intramedullary tumor with exophytic growth.

Adult↗
PubMed1988

[Radiological diagnosis of chronic spinal cord compressive lesion at thoraco-lumbar junction].

Radiological findings in five cases with chronic spinal cord compressive lesion at thoraco-lumbar junction were reported. Three cases had spondylosis and two cases had ossification of yellow ligament (OYL). The levels of the lesions were T12/L1 in three cases and T11/12 in two cases. Two out of three spondylotic patients had also OYL at the same level. The five cases consisted of three men and two women. The ages ranged from 42 to 60 years old with a mean age of 53 years old. Neurologically, every patient showed flaccid paresis and sensory disturbance of the legs. Two cases had sensory disturbance of stocking type. The intervals from the onset of the symptoms to the final diagnosis were 6 months, 7 years, 8 years, 11 years and 12 years. Myelography showed anterior spinal cord compression by bony spur in spondylotic patients, and posterior compression by OYL in other cases. Myelography in flexion posture disclosed the cord compression by bony spur more clearly in two out of three spondylotic patients. Delayed CT-myelography showed intramedullary filling of contrast material in two cases, which indicated degenerative change or microcavitation due to long term compression of the spinal cord. MRI was taken in three spondylotic patients and could directly show compression of the spinal cord. Difficulty in detecting abnormality at thoraco-lumbar junction on plain roentgenogram, and similarity of the symptoms to peripheral nerve disease often lead to a delay in diagnosis. The significance of dynamic myelography and delayed CT-myelography when dealing with such a lesion was discussed here.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Spinal epidural tumors without destructive bone change: clinical and radiological studies].

CT in 61 patients having spinal epidural tumors were reviewed. Of these patients twelve had an epidural mass lacking of destructive bone change. Histological examination of these 12 cases revealed that usual carcinomatous tumors are relatively less common but sarcomatous tumors and malignant hematologic neoplasms are more likely to form an epidural mass without bone destruction. The tumors preponderance thoracic spine and extended usually more than three spinal levels along spinal axis. In all but one tumor masses were found in the intervertebral foramen and the paraspinal region in addition to the spinal canal. Contrast enhanced CT was particularly effective to delineate tumor location and extension. Ring enhancement of the dural sac which constricted by epidural masses was considered pathognomonic of epidural tumors.

Adult↗
PubMed1988

[Thermographic findings of syringomyelia].

Thermographic findings in 10 cases of syringomyelia were reported. 7 cases were associated with Arnold-Chiari malformation and 3 cases with spinal adhesive arachnoiditis. The cases included 3 men and 7 women, aged 7 to 56 years (mean age 27.7 years). Comparing the right side of the body with the left side, in 9 cases, thermography demonstrated asymmetric skin temperature of the trunk or extremities. MRI revealed laterality of the syrinx at the level of cervical or lumbo-sacral cord in 9 cases. The side with the lower temperature corresponded with the side of lateralized syrinx in 8 cases. Neurologically, 9 cases had laterality of sensory disturbance and 6 cases had asymmetric motor weakness. The side with the lower temperature also corresponded with the laterality of sensory disturbance in 8 cases, and the side of the motor weakness in 4 cases. Considering these findings, many of the patients with syringomyelia are thought to have asymmetric skin temperature. Intramedullary involvement of sympathetic pathway by the syrinx may cause such a change. As thermography is non-invasive and easy to carry out, it should be a useful method for estimating or even detecting cases of syringomyelia, especially when applied to out-patients.

Adolescent↗
PubMed1986

[CT-myelography of cervical cord injury].

UNLABELLED: We reported seven cases of acute cervical cord injuries who were examined by CT-Myelography (CTM) within 7 days after trauma. The presence or absence of spinal cord enlargement, the initial neurological status and the neurological prognosis of these patients were studied. The neurological status of each patient was graded by the method of Frankel who defined five grades from A to E according to the severity of neurological deficits. Seven patients were all males. The youngest was 18 and the oldest was 73 years old, with a mean age of 40.7 years. Follows up periods ranged from 7 to 23 months. RESULT: CTM revealed the enlargement of spinal cord in two cases, who had severe neurological deficits and were graded to A. No neurological improvements were obtained in these cases. Five cases without cord enlargement were graded to A in one patient, B in one patient and C in three patients. Four of these five patients improved neurologically. One grade C patient remained grade C. Complete block of subarachnoid space was observed in two out of seven cases. Cord enlargement was present in one of them. Another case of complete block improved from C to D. CONCLUSION: We consider the presence of cord enlargement which can be demonstrated by CTM well correlates the severity of the cord damage and presume poor neurological prognosis. Internal decompression, such as posterior longitudinal myelotomy may be recommended to the case of cord enlargement. When the cord enlargement is absent, improvement of neurological grade is expected although the initial neurological status shows severe deficits.

Adolescent↗
PubMed1985

[External immobilization of cervical spine with a halo vest--experience with 31 cases].

Post-traumatic or post-operative immobilization of cervical spine often requires long term bed-rest. But, bed-rest indeed gave discomfort to patients, nonetheless, sometimes complete external fixation cannot be gained. Since 1982, we have applied Halo vest to the patients who required external immobilization of cervical spine. In this paper, we reported our experiences with 31 cases who were treated by Halo vest. Thirty-one cases comprised 19 cases of cervical spinal trauma, 5 cases of atlanto-axial dislocation, 1 case of foramen magnum meningioma, and 6 cases of ossification of posterior longitudinal ligament (OPLL). In traumatic cases, Halo vest was used as external fixation of injured spine in 8 cases, and as an adjunct to surgical fusion in other cases. In case of atlanto-axial dislocation, 3 cases underwent posterior fusion, and 2 cases underwent anterior fusion. Anterior fusion of C1-2 was also done in case of foramen magnum meningioma after total excision of tumor. Six cases of OPLL underwent anterior decompression and anterior fusion. Mean immobilization time by Halo vest was as follows: 58 days (28-113) in case of cervical spinal trauma, 85 days (56-144) in case of atlanto-axial dislocation who underwent posterior fusion, 92 days (89-93) in case of atlanto-axial dislocation and foramen magnum meningioma who underwent anterior fusion, 59 days (54-70) in case of OPLL. Early ambulation was achieved in many cases. Good external fixation and result was obtained 27 cases out of 31 cases. Re-dislocation of cervical spine occurred in 1 case of cervical spinal trauma while he was in Halo vest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Nidus embolization of cerebral arteriovenous malformation fed mainly by a pericallosal artery prior to surgical excision. Case report].

Nidus embolization of large arteriovenous malformation (AVM) by silastic spheres is not rarely performed prior to surgical excision of AVM. This technique is highly indicated for the large AVM supplied by the middle and the posterior cerebral arteries since silastic spheres injected into either the internal carotid or the vertebral arteries usually enter the middle or the posterior cerebral arteries due to less sharp angle from the main arteries. The authors report a case whose AVM, fed mainly by the anterior cerebral artery, was successfully embolized with silastic spheres using balloon catheter technique. On December 1, 1983, a 27-year-old man was admitted to our department with chief complaint of headache and clonic convulsion of the left upper and lower limbs. Convulsion began in 1973 and severe headache suddenly appeared two months prior to admission. He was neurologically asymptomatic on admission. Right internal carotid angiogram taken on admission showed a presence of large arteriovenous malformation in the medial portion of the right fronto-parietal lobe and corpus callosum fed mainly by the right pericallosal artery. Nidus embolization with silastic spheres was planned to make surgical removal easier. To prevent stray of silastic spheres into the right middle cerebral artery, balloon, introduced into the M1, was inflated for a few minutes, during which time, injection of 40 silastic spheres of 1.5 and 2.0 mm in diameter was performed via the right internal carotid artery. The nidus was significantly reduced and total removal of the nidus was successfully done 28 days following the embolization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗