Prior transient ischemic attacks may have a neuroprotective effect in patients with ischemic stroke

INTRODUCTION Although functional recovery and survival after ischemic infarction seem to improve in patients with prior transient ischemic attack (TIA), little is known about the role of characteristics of prior TIA in subsequent cerebral infarction. Thus, the objective of this study was to explore how the characteristics of prior TIA have a neuroprotective effect on patients with ischemic stroke. MATERIAL AND METHODS A total of 221 patients admitted consecutively to a primary care center for first-ever ischemic stroke were divided into two groups on the basis of the presence or absence of prior TIAs. The initial NIHSS modified Rankin Scale was used to measure the severity and disability after the stroke. Subgroups were based on the TIA duration (< 10 min, 10 to 60 min, and > 60 min), TIA frequency (1 time, 2-3 times, more than 3 times), and the interval of stroke (< 1 week, 1-4 weeks, > 4 weeks). The severity of the neurologic picture on admission and functional disability after stroke were compared between patients with and without TIAs and subgroups as well. RESULTS A total of 132 (59.73%) of the 221 patients had prior TIAs before stroke. Risk factors and the initial clinical picture did not differ between patients with or without TIAs. Patients with prior TIA had a more favorable outcome than those without TIA (59.09% vs. 43.82%), and a significant difference between the two groups was observed (χ² = 4.976, p = 0.026). Furthermore, neurological outcome in patients with prior TIA lasting for 60 min, less than 3 times and shorter intervals within 4 weeks was significantly different from that in the non-TIA group (p < 0.05). CONCLUSIONS Prior transient ischemic attacks may have a neuroprotective effect on the subsequent ischemic stroke, and this effect might be affected by the characteristics of TIAs. Patients with TIAs of low frequency, short duration and short interval are considered to have better neurological outcomes.