Outcome of TIAs of unknown aetiology following non-invasive evaluation

A proportion of patients with apparently classical transient ischaemic attacks (TIA), will have no cause for their symptoms discovered when investigated. We have reviewed 74 patients with TIA and a further 28 with amaurosis fugax whose symptoms remained unexplained following non-invasive carotid evaluation using pulsed Doppler imaging with spectrum analysis. After a mean follow-up of 31.7 months, 48.6% of TIA patients were symptom free, 36.5% had experienced recurrent symptoms and 8.1% had suffered a stroke. Among the patients with amaurosis fugax the equivalent figures were 32.1% symptom free, 42.7% recurrent symptoms, and 10.7% stroke. These figures suggest that unexplained TIAs do not necessarily have a benign prognosis and more extensive or repeated investigation of these patients is warranted.