The ischaemic penumbra is an important focus of our research. This is brain tissue which, while damaged, continues to live after the onset of the stroke process. The duration of this is uncertain in humans although we have the ability to create images of its behaviour using positron emission tomography (PET) and magnetic resonance imaging (MRI).
Using MR we have shown that salvageable (penumbral) brain tissue may last up to 48 hours post stroke onset and that the distribution of this salvageable tissue becomes more variable with time. Further, improved computer co-registration techniques may identify more patients than previously realised who have penumbral tissue. This may expand the number of patients eligible for treatment with thrombolytic agents such as tPA.
Another initiative of significance is the use of PET using 18F-PIB to image amyloid plaque in patients with recent onset ischaemic and haemorrhagic stroke. There are interesting links between vascular dementia, stroke and Alzheimer's disease which may be, in part, unravelled using this technique.
The ultrasound laboratory is completing an investigation concerning the clinical significance of a newly appreciated ultrasound sign, referred to as “small vessel knock”. The FNI is collaborating with Compumedics DWL, a Melbourne-based transcranial Doppler ultrasound company, to determine whether knock is useful in the diagnosis of stroke.
“The human species is made up of seven billion subspecies each consisting of one specimen.”
