Summary
50 patients from a group of 130 patients with transient ischaemic attacks or cerebral
infarction were found to demonstrate in vitro spontaneous platelet aggregation (SPA) while 80 normal subjects tested never showed
this phenomenon.
The following additional findings point towards a possible platelet abnormality:
1. Platelets from 10 patients with SPA when isolated and resuspended in normal plasma
still demonstrated SPA while isolated normal platelets resuspended in patient’s plasma
did not.
2. Platelets demonstrating SPA showed an increased aggregation tendency upon incubation
with ADP while normal platelets developed the expected refractory state.
SPA was found to be dependant upon the presence of divalent cations and could further
be inhibited by phentolamine and adenosine. Aspirin effectively abolished SPA in 50
patients and relieved the clinical symptoms of patients with recurrent complaints
of transient blindness and paraesthesia.
