Clinical features, including atypical symptoms, associated with acute cerebral ischaemia on DWI-MRI in suspected TIA and minor stroke

BACKGROUND AND AIMS: The diagnosis of transient ischaemic attack (TIA) and minor stroke can be challenging. Current diagnostic criteria for TIA disqualify atypical clinical presentations which may nevertheless be associated with objective cerebral ischaemia on DWI-MRI. We aimed to: (1) ascertain the proportion of DWI-positive patients with atypical clinical presentations; and (2) identify clinical factors predicting DWI positivity. METHODS: We retrospectively reviewed case notes of consecutive patients with suspected TIA or minor stroke undergoing MRI at our comprehensive stroke centre. We identified clinical factors predicting DWI positivity using multivariable logistic regression. RESULTS: We included 1615 patients. Of 442 (27.4%) who were DWI-positive, 38.5% had atypical presentations; common symptoms included headache (present in 17%), unsteadiness (15%), positive sensory symptoms (11%), presyncope (10%), confusion (9%) and vertigo (8%). Symptoms independently associated with DWI-positivity included weakness (OR 1.30 95% CI 1.01-1.67), dysarthria (OR 2.05 CI 1.56-2.70), and ataxia (OR 3.76 CI 2.27-6.21). Fluctuating symptoms (present in 21.5%) predicted DWI positivity (OR 1.37 CI 1.04-1.81), but sudden onset (80.1%) did not (OR 1.05, CI 0.80-1.38). Risk factors associated with DWI positivity included increasing age (OR 1.02/year CI 1.01-1.02), hypertension (OR 1.61 CI 1.23-2.11), diabetes (OR 1.40 CI 1.04-1.90), and smoking (OR 1.67 CI 1.17-2.37). DWI-positive patients had significantly more risk factors (mean 2.65 vs 1.95 p=<0.001). CONCLUSIONS: Over one-third of people with MRI DWI-confirmed TIA or minor stroke present with atypical symptoms. MRI-DWI is essential to diagnose cerebral ischaemia in patients with atypical symptoms, particularly in those with vascular risk factors.