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.

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.

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.

[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)

[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.

[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.