QUANTITATIVE RHEOLOGICAL EVALUATION OF THE EFFECT OF NAFTIDROFURYL ONDISORDERS OF THE CEREBRAL MICROCIRCULATION

Impaired oxygenation due to microcirculatory changes within the cerebr al parenchyma may contribute to deterioration of intellectual function in vascular senile dementia (Hachinski score greater than or equal to 7). The action of naftidrofuryl, used for treating elderly patients w ith senile dementia, was evaluated objectively in two groups of patien ts given naftidrofuryl either as a single intravenous dose or by chron ic oral administration for three months. Their cerebral, microcirculat ory flow rate was assessed before and after treatment by in vivo cinea ngioscintigraphy following an i.v. bolus of Tc-99m labelled erythrocyt es. The deformability of erythrocytes from orally treated patients was also measured using an in vitro cellular transit time analyser (CTA) technique. A further experiment assessed the theology of a rigid sub-p opulation of erythrocytes in pathological samples when exposed to naft idrofuryl at concentrations appropriate to clinical use. Cerebral flow rates increased by about 20% and 30% after intravenous or chronic ora l naftidrofuryl, respectively and these differences were statistically significant. In 10 orally treated patients, mean transit times by CTA decreased from 3.12 ms (day 0) to 2.70 ms (day 87 of treatment) (p< 0 .01). In the presence of naftidrofuryl, the proportion of the least de formable erythrocytes in pathological samples decreased by at least 50 %. Clinical effects of naftidrofuryl on the cerebral microcirculation were not restricted to acute exposure. Naftidrofuryl may enhance the d eformability of individual erythrocytes.