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We studied myocardial accumulation and clearance of [123I]metaiodobenzylguanidine (MIBG) along with measurements of plasma norepinephrine concentrations.Myocardial imaging with MIBG and plasma norepinephrine concentration measurements were performed in 21 patients with chronic renal failure on dialysis and 11 control subjects. Dynamic acquisitions, begun immediately after MIBG injection, and planar images 15 and 150 min after injection were used to measure early and late myocardial uptake and clearance rates of MIBG from the heart.Early and late MIBG uptake was not significantly different from that in controls but MIBG clearance was significantly more rapid in controls. Based on echocardiographic findings, the patients were divided into three subgroups: those without left ventricular hypertrophy and dysfunction (n = 10), with hypertrophy (n = 4) and with dysfunction (n = 7). Among controls and the three patient subgroups, MIBG clearance was significantly higher in all the subgroups and also was significantly higher in patients with dysfunction than in those without hypertrophy and dysfunction. Plasma norepinephrine levels were significantly higher in patients than in controls and correlated significantly with the clearance rate.MIBG clearance from the heart was rapid in patients with chronic renal failure on dialysis, particularly those with left ventricular dysfunction or hypertrophy, suggesting cardiac sympathetic overactivity in these patients.

The patient was a 35-year-old man with confusional state and headache. Analysis of cerebrospinal fluid (CSF) showed 1,383/mm3 cell count, the protein level of 300mg/dl and glucose level of 42 mg/dl. Cryptococcus neoformans was disclosed by India ink preparation. The cryptococcal antigen test was positive at 1:125 by latex agglutination. The diagnosis of cryptococcal meningoencephalitis was determined. Antifungal treatment with amphotericin B resulted in improvement of neurologic signs, CSF findings and cryptococcal antigen test. But two months later, brain MRI demonstrated low intensity areas on T1 weighted image and high intensity areas on T2 and proton weighted images in the cerebral cortical region. Gd-DTPA MRI showed enhanced areas in the cerebral leptomeninges. It was considered that these MRI lesions corresponded to pseudocysts and Gd-DTPA enhanced lesion indicated dilated vessels or destructed blood-brain barrier. After administration of larger doses of amphotericin B, these lesions on MRI disappeared. It is suggested that brain MRI is useful in diagnosis of cryptococcal meningoencephalitis to detect pseudocysts at the cortical region which may imply the early stage of procrastinating process.

CT findings in primary low spinal fluid pressure syndrome are studied on the basis of 3 cases. Case 1 was a 43-year-old male with a complicated bilateral isodense subdural hematoma (SDH). Case 2 was a 45-year-old female with a complicated bilateral high dense SDH. Case 3 was a 36-year-old female discharged without any complications after spinal fluid pressure normalized. Slight downward displacement of the brain under low spinal fluid pressure is shown as the narrowing of with a Sylvian fissures and infratentorial cisterns on CT. On the other hand in this syndrome with a complicated bilateral isodense SDH, in addition to this finding CT reveals distortion and narrowing of body of lateral ventricles, which may be the differential findings from this syndrome without complicated SDH. Under low spinal fluid pressure, bridging veins are more stretched by a downward displacement of the brain. And consequently they are easily insured and SDH is developed.

A 43-year-old man with no history of trauma or neurosurgical procedure was admitted our hospital because of orthostatic headache made worse in upright position. Spinal fluid pressure was 0 mmH2O, and CT scan revealed wide cortical sulci and ventricles. In the 26th hospital day he had severe headache and CT scan revealed bilateral subdural hematoma, then neurosurgical procedure was done. About 2 months later, he was relieved of the headache and spinal fluid pressure returned to normal. We performed lumbar isotope cisternography and isotope choroid plexography in our case when low spinal fluid pressure and normalized pressure. Isotope cisternography revealed the radioactivity counts decreased rapidly in low pressure and normal in normal pressure. On the other hand isotope choroid plexography was almost no difference between low and normal pressure. Our data suggest that primary low spinal fluid pressure syndrome is not caused by hypoproduction, but by an undetectable leak from a minute tear in a spinal root sleeve or hyperabsorption at the spinal arachnoid membrane.

It has been well established that acquired lesions of the corpus callosum such as surgical section bring about disturbances of interhemispheric transfer of visual information. In contrast, patients with callosal agenesis do not display these specific deficits. The mechanisms of this compensation have been postulated as follows; (1) bilateral development of language function, (2) exploitation of extracallosal commissure fibers such as the anterior commissure. Several studies have reported, however, minor disturbances of interhemispheric visual transfer in callosal agenesis, such as less efficient interhemispheric transfer of complex visual stimuli (GottSaul, 1978), slower reaction time in interhemispheric comparison of visual stimuli (SauerweinLassonde, 1983), or deficits in spatial localization in the right hemi-field (Martin, 1985). In order to settle these issues, we have administered four kinds of tachistoscopic visual recognition tests on 4 patients with complete agenesis of the corpus callosum confirmed by magnetic resonance imaging (MRI). This technique enabled us to see the mid-sagittal plane of the corpus callosum and diagnose its total absence with much higher certainty and precision than previous studies employing computed tomography (CT) or pneumoencephalography. Case 1: A 41-year-old right-handed man visited us because of recurrent numbness in the four extremities. Neurological examination revealed no abnormalities. MRI has confirmed that the corpus callosum was totally lacking, and that the anterior commissure was normally visualized. Case 2: A 31-year-old right-handed man was referred to us for the treatment of partial complex seizure. Total agenesis and lipoma of the corpus callosum was diagnosed by MRI and reconstructed sagittal view of CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)