[Causative factors resulting in intractability of congenital hydrocephalus--analysis of psychomotor development and MRI findings of the brain in sixteen congenitally hydrocephalic patients].

Sixteen patients out of 58 children with congenital hydrocephalus were retrospectively investigated in terms of their psychomotor development and morphological findings of the brain by magnetic resonance imaging (MRI), and morphological backgrounds of the brain in patients affected by "intractable hydrocephalus" were intended to be clarified. The 16 patients were primarily diagnosed as having aqueductal stenosis or communicating hydrocephalus during the era before introduction of MRI. On the basis of the rate of head growth, sixteen patients were divided into three groups; group-1: overt neonatal hydrocephalus (5 cases) ; group-2: rapidly progressive hydrocephalus with normal head circumference at birth (5 cases); and group-3: slowly progressive hydrocephalus with its onset after the neonatal period (6 cases). Psychomotor development of the 16 cases was analyzed by using various methods including the Tanaka-Binet intelligence test and WISC-R. Four cases in group-1 and all cases in group-2 were found to have IQ or DQ below 50, while the other remaining cases were found to have IQ of 82 in group-1 (one case) and IQ ranging from 67 to 113 in group-3. MRI performed in those 9 cases with IQ below 50 revealed various morphological abnormalities of the brain. Those abnormalities were characterized by disturbance of organogenesis and/or histogenesis of the brain dating from the first 20 weeks of fetal life. It is strongly suggested that in the pathogenesis of intractable hydrocephalus developmental malformation of the brain occurring during the first 20 weeks of gestation are involved. Functional and morphological impairments of the brain possibly caused by progression of fetal hydrocephalus and delay of CSF diversion before and after birth seem important in the pathogenesis of intractable hydrocephalus.

Corticobasal degeneration: MR with histopathologic comparison.

The purpose of this study was to illustrate the MR findings of corticobasal degeneration and to compare those findings with pathologic specimens. MR findings of atrophy in the perirolandic gyri, atrophy of the basal ganglia, and T2 prolongation in the posterolateral putamen are useful evidence supporting the clinical diagnosis of corticobasal degeneration.

Serial neuroradiological studies in focal cerebritis.

We report serial neuroradiological studies in a patient with focal cerebritis in the head of the left caudate nucleus. On the day after the onset of symptoms, CT showed an ill-defined low density lesion. The lack of contrast enhancement appeared to be the most important finding for differentiating focal cerebritis from an encapsulated brain abscess or a tumour. MRI two days later revealed the centre of the lesion to be of slightly low intensity on T1-weighted inversion recovery (IR) images and very low intensity on T2-weighted spin echo images, which appeared to correspond to the early cerebritis stage of experimentally induced cerebritis and brain abscess. Ten days after the onset of symptoms, CT revealed a thin ring of enhancement in the head of the caudate nucleus, and a similar small ring was seen in the hypothalamus 16 days after the onset, corresponding to the late cerebritis stage. MRI nine days later revealed ill-defined high signal lesions within the involved area on the T1-weighted IR images. To our knowledge, this is the first published MRI documentation of the early cerebritis stage developing into an encapsulated brain abscess. The mechanisms underlying of these radiographic changes are discussed.

[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.

Neurosyphilis manifesting as a focal mass lesion: computed tomographic and magnetic resonance imaging features--case report.

The computed tomographic (CT) and magnetic resonance (MR) imaging findings in a middle-aged male with cerebral syphilis are described. He presented with convulsive seizures and focal neurological deficits. A CT scan revealed a slightly enhanced, low-density mass in the left parieto-occipital region. MR imaging showed low intensity on T1-weighted images and high intensity on T2-weighted images. He was initially diagnosed as having a low-grade glioma. However, intraoperative histological examination of a small surgical specimen revealed no tumor cells but heavy infiltration of inflammatory cells in the meninges and cerebral parenchyma. Immunostaining for Treponema organisms by the peroxidase-antiperoxidase method was positive. Although the clinical and radiological findings are nonspecific, neurosyphilis should be considered in any patient in whom a nonspecific mass lesion is demonstrated by CT and MR imaging.

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.

[Visibility of the inferior horns in computed tomography of normal subjects and epileptics].

In recent years brain CT scan has been so popular that many investigators have been trying to clarify the normal CT images. But little attention has been paid to the inferior horns of lateral ventricles in spite of their importance for judging mesial temporal lobe structures. The present study was designed to elucidate how the inferior horns were visualized on brain CT in normal subjects from childhood to aged group, and to evaluate whether the inferior horns were dilated in the epileptics or not. The subjects of the present study were 502 normal controls (2-79 y, mean 36.1 y) and 163 epileptic patients with normal CT image (4-68 y, mean 26.6 y) including 55 cases of temporal lobe epileptics. CT scans were performed with EMI 1010 scanner, and slices were obtained every 10 mm from the projection of 5-10 degrees angle for orbito-meatal line. Inferior horns were examined at the level of basal cisterns. Because inferior horns were not necessarily visible in our cases, we examined the frequency of clearly visualized inferior horns at each decade, and regarded their frequency as the size of inferior horns at each decade. In normal controls, frequency of visible inferior horns was relatively high in early childhood, and decreased as they grew. In the 3 rd to 4 th decades the visibility frequency became the lowest (30-35%), and then gradually increased as the subjects became older.(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.

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.

Pure memory loss with hippocampal lesions: a pneumoencephalographic study.

A case of pure memory loss occurred suddenly following inhalation anesthesia. Examination seven years after the onset of amnesia disclosed a profound and selective impairment of recent memory without concomitant deterioration of other higher functions or evidence of other neurologic abnormalities. Pneumoencephalotomography focused on the temporal horns showed severe atrophic changes confined to both hippocampi. This finding provides a radiologic counterpart of previously reported surgical and pathological observations of bilateral hippocampal lesions in cases with relatively pure loss of memory.