[目的・対象・方法]内頸動脈系の慢性期の虚血性脳血管障害47例にxanthine誘導体であるpropentofylline及びpentoxifyllineを投与し,投与前後のWAISによる高次脳機能と脳血流量(CBF),血液量(以下CBV),平均通過時間(以下MTT)の定量的評価を行ない有効性の検討を行なった.[結果]投薬前のCBFは正常より低く,CBVは正常範囲であった.投薬後CBFは局所的に増大したが平均値は有意な増加は見られなかった.CBVは有意な増大を示し,pentoxifyllineの併用で更に顕著な増大を示した.MTTも有意な増大を示した.WAIS IQは投薬後改善したが全体では有意な差はなかった.脳梗塞発症から投薬までの期間が短い群では改善傾向が見られた.又投与前のTIQが100点から110点迄の群では有意な改善が得られた.[考察・結論]xanthine誘導体の薬理作用が血管拡張として捉えられたものと思われた.CBVの増大によりMTTは延長し,結果的に脳酸素摂取率が上昇,脳酸素代謝率を正常化すると思われた.
Since vascular dementia is preventable and treatable to a certain degree, a safe therapy that effectively improves the cerebral circulation and metabolism at the chronic phase of cerebrovascular diseases is nceded. We administered two xanthine derivatives, 1-(5'-oxobexyl)-3-methyl-7-propyl-xanthine (propentofylline) and 3, 7-dimethyl-l-(5-oxohexyl) -xanthine(pentoxifylline), to 47 patients aged less than 80 years, who were in the chronic phase of ischemic diseases of the internal carotid artery territory. The propentofylline was ad-ministered alone (22 cases) or in combination with pentoxifylline (25 cases). The therapeutic effects were ovaluated by assessing. The pre-and post-treatment high level cerebral functions using WAIS, and quantitatively measuring the cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) employing single photon computed tomography. Before treatment, the mean CBF was lower than normal at 41.4 (ml/100 g/min) and the CBV was within the normal range at 4.45 (ml /100 g). After treatment, the mean CBF increased but with no significant change. The mean CBV increased significantly after treatment, and it was enhanced in hemispheres with infarct lesions and following combined treatment with pentoxifylline. The MTT was also increased significantly after treatment. The WAIS IQ scores appeared to improve after treat-ment, but with out significant differences. The improvement tended to be greater when the interval from the onset of disease to treatment was short. The group of patients with pretreatment TIQ volues of 100 to 110 showed a significant improvement of their TIQ following pentoxifylline administration. The pharmacological effect of the xanthine derivatives was adjudged as vasodilation. Such vasodilation and a prolonged MTT may consequently increase the cerebral oxygen uptake and normalize the ccrebral metabolic rate of oxygen, resulting in an improvement of intellectual functions.
