[Adverse reactions to low osmolar iodine contrast media (second report)].

From January to December 1990, we performed a prospective survey of adverse reactions to contrast media at two different institutes of Juntendo University. We collected a total of 4555 case sheets during the period. The radiological procedures we investigated were computed tomography, intravenous urography, arteriography, venography and myelography. Low osmolar iodine contrast medium was used almost exclusively (except for five cases). The overall incidence of adverse reactions was 7.0%, and there were no severe or fatal reactions. The incidence of adverse reactions was higher in females (8.5%) than in males (6.1%). The incidence of adverse reactions increased according to the dose of contrast medium, especially when more than 101 ml was injected. Intra-arterial injection caused adverse reactions most often, followed by regular intravenous injections, followed by bolus intravenous injections. Adverse reactions occurred most often during injection. The next occurred in 5 minutes after injection, and then, 5-10 minutes after the injection of contrast medium. The incidence of adverse reactions was higher in patients with a history of allergy or previous reactions. Allergic adverse reactions were observed at a higher frequency. Pretesting was performed in 56.7% of the cases.

[Adverse reactions to low osmolar iodine contrast media].

From January 1989 to December 1989, we performed a prospective survey of adverse reactions to contrast media at three institutes of Juntendo University. We collected a total of 4365 case cards during the period. Low osmolar iodine contrast media were given in all but one case. Procedures using contrast media included computed tomography, intravenous urography, arteriography, venography and myelography. The overall incidence of adverse reactions was 6.6%, and there were no severe or fatal reactions. The incidence of adverse reactions was about the same in both sexes. However, in males, the incidence was higher in the fifth decade, and in females, it was higher in the third and seventh decades. There was no relation between the dose of contrast medium and adverse reactions. Intravenous bolus injections caused adverse reactions more often, followed by intra-arterial injections and then usual intravenous injections. The incidence of adverse reactions in patients with a history of allergy or previous reactions was higher. Pretesting was performed in 48.9% of the cases.

Identification of pre- and postcentral gyri on CT and MR images on the basis of the medullary pattern of cerebral white matter.

The authors illustrate a new method to identify the pre- and postcentral gyri on computed tomographic (CT) and magnetic resonance (MR) images of the brain on the basis of the pattern of the medullary branches of the cerebral white matter. The most commonly used method to identify the gyri depends on recognition of the central sulcus by surface arrangement of the sulci. The two methods were compared by analysis of CT images of 104 subjects who had normal findings (age range, newborn to 60 years; 57 males and 47 females). The usefulness of the new method was also determined in angiographic studies of nine patients with space-occupying lesions. The method is especially helpful for identification of gyri on the lower level of the centrum semiovale and if space-occupying lesions are present that may result in a blurred depiction of sulci. Since MR imaging depicts the medullary branches more clearly than does CT, this new method should facilitate identification of the gyri with either modality.

[CT findings of watershed infarction; comparison of 123I-IMP SPECT and IV-DSA].

A watershed infarction is a specific type of a cerebral infarction. This occurs at the border zone between major cerebral arteries. Its CT findings are characteristic as a wedge shaped low density appearing either in the superior frontal region (watershed between anterior and middle and posterior cerebral artery), and always involving the deep white matter onto the ventricle wall. Even though the CT feature is small, a patient, without exception, suffers from neurologic deficit. We studied four cases of a watershed infarction on X-ray CT and compared with 123I-IMP SPECT. DSA was also made to demonstrate an obstruction of an artery which was usually found at the more proximal segment then what we expected from the CT feature. The findings on the 123I-IMP SPECT were better predictable of neurologic symptoms and they were larger in extent than the CT findings.

Left-right asymmetry of the temporal and parietal regions in children: based on the medullary pattern of cerebral white matter.

Lateralization of the posterior temporal lobe and inferior parietal lobule in childhood was studied on CT of 276 cases and compared with those in adulthood of 371 cases. CT images were analyzed based on the morphological features of medullary branches of the cerebral white matter. In children below 5 years of age, the left planum temporale was already more posteriorly located than the right in 56%, while the right was more so in 21%. The asymmetry of the middle temporal gyrus was similar to those of the planum temporale. The folding of the inferior parietal lobule was extensive and intricate on the left side in 63% and on the right side in 8% of children, almost identical to those in the adult. The visualization rates of the intraparietal sulcus were lower compared to those of the adult, but the higher visualization of the left side was a common tendency regardless of age. These alterations in left-right asymmetry seemed to be a morphologic substratum indicating the processes of localization of auditory function to those association areas.

MRI findings in the mild type of mucopolysaccharidosis II (Hunter's syndrome).

Neuroradiological findings in a 44-year-old male with the typical mild type of Hunter's disease are reported. Cranial MRI revealed patchy areas of increased and decreased signals in T1- and T2-weighted images in the thalamus and the basal ganglia giving rise to a honey comb-like appearance as a whole. The deep white matter showed high signals in the T2-weighted image. To our knowledge, the honey comb-like appearance has never been reported in this disorder. Deposition of mucopolysaccharides and/or glycolipids and increase in fluid content seem to be responsible for these changes.

'Salt and pepper on the face' pain followed by cardiac and respiratory arrests. The stormy postoperative manifestations after the surgery of posterior fossa arteriovenous malformation.

The authors describe 'salt and pepper on the face' pain in a case of medullary arteriovenous malformation (AVM), which was caused by post-operative hemorrhage from a very small residual nidus of AVM left remaining in the left dorsal medulla. The peculiar, sharp, jabbing pain, which has been rarely reported at the onset of intracranial hemorrhage, was followed by acute elevation of blood pressure, arrhythmia, cardiac and respiratory arrests. The patient had been in a comatose state for a month and gradually recovered from the cardiopulmonary and neurological derangements. The pathophysiology of the phenomenon which occurred in this case is discussed.

[Intramedullary schwannoma with extradural extension: case report].

Intramedullary schwannoma without evidence of von Recklinghausen's disease is extremely rare. Only 23 cases have been reported in the literature. A 42-years-old woman with transverse type myelopathy at the level of Th 6, was referred to our department. Myelography showed diffuse swelling of the thoracic cord. Delayed myelo CT scan revealed the existence of syrinx at C 6 and Th 10 spinal cord level. On NMR spin echo image, high intensity signal with an ovoid shape was visualized in Th 7-8 spinal cord parenchyma and the syrinx was verified below the level of C 5. Based on these findings, she was diagnosed as having Th 7-8 intramedullary spinal cord tumor. Th 6 to Th 9 laminectomy followed by the complete removal of well encapsulated tumor was performed. The rostral and caudal pole of the tumor was found to be located intramedullary. The tumor at the level of Th 7-8, extended not only to the extramedullary space but also to the extradural space. Histopathological examination revealed that the specimen was Antoni A type neurinoma. She showed good recovery. Following hypotheses have been postulated on the cytogenesis of intramedullary schwannoma in the literature: Central displacement of Schwann cells during embryonic development. Schwann cells ensheathing aberrant intramedullary nerve fibers. Schwann cells along the intramedullary perivascular nerve plexus. A critical area where posterior root loose their sheath on entering the pia mater. Transformation of pial cells of neuroectodermal origin into Schwann cells. The cytogenesis of these reported cases may not be identical.(ABSTRACT TRUNCATED AT 250 WORDS)

Left-right asymmetry in the temporal and parietal region based on the medullary pattern of cerebral white matter.

Left-to-right differences in cerebral structures of the posterior temporal and inferior parietal region were investigated in CT examinations from 500 cases, by anatomic analysis based on the medullary branches of cerebral white matter. On the left side, the planum temporale and middle temporal gyrus were positioned more posteriorly, the intraparietal sulcus was deeper and lower, and the folding of the inferior parietal lobule was more extensive. The lateralization of the planum temporale diminished gradually from 19 years of age downwards. An anatomic analysis of the medullary branches succeeded in revealing the cerebral asymmetry and is expected to be useful in magnetic resonance imaging.

Surgically confirmed myelographic classification of congenital intraspinal lipoma in the lumbosacral region.

Twenty-four cases of histologically confirmed congenital intraspinal lipoma of the lumbosacral region were studied by means of myelography with metrizamide. The findings were compared with intraoperative observations. Myelography with metrizamide clearly revealed the detailed intrathecal structures and allowed a classification of intraspinal lipomas into four types, in terms of their insertion into the conus medullaris: dorsal type, either with direct or indirect (via an intrathecal stalk) insertion of the extrathecal lipoma into the dorsal aspect of the conus medullaris; caudal type; combined type; and filar lipoma. Based on our surgical experience in untethering and decompression of the lesions, the classification was found to be useful in designing a safe and effective surgical procedure which minimized all possible trauma to the intrathecal neural structures.

Cervical radiculomyelopathy due to calcification of the ligamenta flava.

Three cases of cervical radiculomyelopathy caused by calcification of the ligamenta flava of the cervical spine are reported. A review of the literature yielded 13 cases of calcification of the cervical ligamenta flava with findings similar to those in our cases. Specifically, we observed that 1) all patients were more than 50 years of age; 2) most were female; and 3) the calcifications appeared consistently as oval nodules, located symmetrically and paramedially in and around the region of the fifth cervical vertebra. Such characteristic similarities in both clinical and radiologic features are important in considering the etiology of calcification of the cervical ligamenta flawa.

Middle fossa arachnoid cyst: clinical, neuroradiological, and surgical features.

16 patients and 4 adult cases of small-or medium-sized middle fossa arachnoid cyst were subjected to various neuroradiological investigations and their results were analyzed in terms of possible mechanisms of cyst expansion. Based on the results of the investigations which strongly suggested that the cyst is an expanding lesion, all cases were surgically treated by the same techniques of craniotomy, excision of the outer cyst membrane, followed by a cystoperitoneal shunt, resulting in complete disappearance of the cyst concomitant with reexpansion of the surrounding brain and marked improvement in the clinical pictures of the patients.

[Radiculomyelopathy due to calcification of the cervical ligamenta flava--report of 2 cases and a review of literature].

Calcification of ligamenta flava in the cervical spine is rarely seen. Only few cases in the literature have been available. Recently we have had experience with two cases on that lesion who had progressive radiculomyelopathy. The purpose of this report is not only case presentation but also an analysis of 11 cases from the literature in clinical, radiological and histological aspects. Case 1 was a 60-year-old woman who had numbness in both hands, mild weakness of the right foot on walking and clumsiness of the right hand. Ten years before she had suffered tbc. meningitis, but no history of neck injury. Neurological examination revealed spastic paresis in right extremities, muscle atrophy in both forearms, hypesthesia and hypalgesia in both hands and feet. Vibration sense was disturbed below the knee joint and both feet. Sphincter function was normal. Radiological examination of cervical spine revealed oval calcified nodules in the posterior spinal canal at the level of C34, C45, C56 and C67. These were all situated in the paramedian portion and symmetrically situated at C56. Air myelogram demonstrated that the spinal cord was displaced forward and choked by the posterior situated calcification. Cervical laminectomy was carried out from C2 through Th1 and calcified nodules in the hypertrophied ligamenta flava were successfully removed. Case 2 was also 66-year-old woman who had been suffering from cerebral thrombosis with left hemiparesis. In addition with left hemiparesis she started to complain with paresthesia in right hand, deteriorated numbness in left extremities and gait disturbance developed a year later.(ABSTRACT TRUNCATED AT 250 WORDS)