Diseases of the central nervous system. Cerebral atherosclerosis, transient ischaemic attacks, Menière's disease, and disorders of balance

Effects of adenosine diphosphate administration on the vestibulo-oculomotor reflex of rabbits

Adenosine diphosphate (ADP) injection into a unilateral vertebral artery in rabbits decreased per-rotational nystagmus; the nystagmus beating toward the injected side was predominantly suppressed. This influence became obvious when the animal's blood pressure was low. Field potentials were recorded in the vestibular nuclei upon electric stimulation of the vestibular labyrinth. ADP administration into the vertebral artery also suppressed the amplitude of vestibular evoked potentials (VEPs). Effects of ADP upon the vestibulo-ocular reflex and VEP were considered to be due to regional ischemia induced by the microemboli, which consisted of platelet aggregation.

The effect of pentoxifylline ('Trental') on cerebral blood flow: a double-blind study

A double-blind, placebo controlled crossover study was carried out in 20 geriatric patients with cerebrovascular insufficiency ot asses the effect of pentoxifylline on cerebral blood flow. Using 99m Tc cerebral scinitigraphy and a gamma comera/computer system, the pattern of blood flow in 5 brain areas was manitored after a single intravenous infusion of 200 mg pentoxifylline (10 ml) and after 10 ml saline solution. The results showed that, with the exception of one brain area, there was a statistically significant increase both in regional and hemispheric cerebral blood flow after pentoxifylline. It is of particular interst that global hemispheric blood flow, which gives an indication of total blood supply to the brain, showed approximately the same percentage increase on both sides with pentoxifylline.