We investigated the role of traumatic subdural fluid collection in the genesis of chronic subdural hematoma (CSDH) in 43 consecutive patients with traumatic subdural fluid collection. Traumatic subdural fluid collection was found in 43 (6%) of 715 patients who underwent CT scans because of head injury. Twenty-four of the 43 patients were more than 65 years of age and this problem occurred in 30% of the 79 head-injured patients over 65 years of age. In 20 (Group 1) of the 43 patients CSDH subsequently developed. During the same period, 30 other patients were treated for CSDH. Twenty-four (Group 2) of these 30 patients had a history of head injury more than two weeks prior to the developing sings and symptoms and had hyper- or iso-dense hematomas on their first CT scan. It may have been that they too first had a traumatic subdural collection. Forty to sixty percent of the patients with asymptomatic traumatic subdural fluid collection may develop CSDH, and this may occur especially in the older patients. Careful observations after the head injury are particularly important in the aged because of the frequent occurrence of traumatic subdural fluid collection and the subsequent development of CSDH.
We introduced a simplified method of xenon-enhanced CT (SXe-CT) for obtaining the topographic regional cerebral blood flow (rCBF) map. In the SXe-CT, we used the method of brief (three to four minutes) inhalation of 40% xenon. To shorten the period of xenon inhalation, we substituted a predetermined brain-blood partition coefficient (L) in the entire brain for the directly estimated L to calculate the rCBF value. Because of its non-invasiveness and simplicity, the SXe-CT can be applied to the patients with diseases in the central nervous system (CNS) without any difficulties.
During the past three years, we performed the SXe-CT on 150 occasions in 100 subjects, including those with moyamoya disease, other ischemic cerebrovascular diseases, arteriovenous malformations and normal pressure hydrocephalus. In this paper, the rCBF values of seven normal healthy adults with a mean age of 24 years are reported and the flow maps of some cases of CNS diseases are presented. The normal mean value of the hemispheres was 53, those of the gray matter were in the range of 38 to 72, those of the white matter were in the range of 26 to 35 and those of the basal ganglia and thalamus were 55 to 88 (values are given in ml/100g/min). The SXe-CT has potential advantages in obtaining clinically useful rCBF measurements.
Family studies and blood grouping tests were conducted in an attempt to elucidate the etiology and genetic mechanism of ossification of posterior longitudinal ligament of the spine (OPLL). Analysis of the collected date revealed the following results:
(1) Testing of inheritance pattern
Fitness of OPLL to the hypotheses of simple recessive inheritance, simple dominant inheritance and multifactorial inheritance was tested, but fitness to any one of these hypotheses was statistically denied.
(2) Analyses of OPLL and genetic markers
A comparative study was made between the OPLL patients and healthy donors residing in Tokyo on the phenotype frequency of the blood groups (eight systems), serum groups (six systems) and red cell enzyme groups (three systems). A significant association of OPLL with MN blood groups, Hp types and PGM1 types was observed. Examination of the correlation after combining MN and Hp showed the coefficient of contingency to be C=0.6739 and that after the multiple combination of M N, Hp and PGM1 revealed the coefficient of contingency to be C=0.8923, indicating a remarkably high correlation.