[Point of view. Transient ischemic attacks. Is a reassessment needed?].
The clinical definition of transient ischemic attacks (TIAs), besides the ischemic pathogenesis is based (i) upon 24 h. duration and (ii) complete reversibility. The limit of 24 h. has been chosen arbitrarily and episodes clearing completely after more than 24 h. do exist. In addition TIAs lasting less than 5 min. would have a higher incidence of subsequent completed stroke. Complete reversibility has also been disregarded: ischemic attacks leaving slight neurological deficits or showing an hypodense area at CT scanning have been shown to have the same significance at TIAs. Different clinical definitions and classifications account for very different natural history features reported in the literature. Transient attacks may be conveniently assessed under the label of Reversible Ischemic Attacks (RIA) covering attacks of 24 h. duration (TIA) and attacks of more than 24 h. duration (Protracted Transient Ischemic Attacks. PTIA). Terms such a RIND or PRIND (Reversible Ischemic Neurological Deficit or Prolonged Reversible Ischemic Neurological Deficit) should be disregarded since they are too general terms covering both cases with 24 and more than 24 h. duration. TIAs and PTIAs should be characterized by a complete clinical regression and normal CT, to avoid relevant wrong diagnostic statements (transient attacks in cases of lacunar stroke, hemorrhages, tumours); where clinical regression is partial and/or CT shows low attenuation areas the case should be labelled as one with partial non progressing stroke (PNS) or minor stroke. The question however arises whether TIA, PTIA or PNS significantly differ from each other from the clinical, prognostic and therapeutic standpoint or, on the contrary, any attempt to differentiate them on these grounds should be considered futile as suggested be Caplan (1983).(ABSTRACT TRUNCATED AT 250 WORDS)