Inclusion Criteria- Patients aged >18 years of age presenting within 9 hours of onset of symptoms will be recruited from the hyperacute stroke unit at UCLH.
- Patients in whom stroke has been excluded or in whom intracerebral haemorrhage has been diagnosed are to be included as 'controls'. The definitive diagnosis will not be immediately obvious at presentation.
- Written consent will be obtained from patients or their nearest relative, particularly in patients with aphasia/dysphasia.
Exclusion Criteria- Patients <18 years old
- Patients with systemic vasculitis or active malignancy will be excluded.
- Patients not wishing to participate