Methods and devices to detect stroke in a subject

A method of determining the absence of an acute cerebral disorder in a subject comprising:

• a. measuring the concentration of one or more purines in a body fluid of the subject using a biosensor comprising an electrochemical cell, where the purines are selected from the group consisting of adenosine, inosine, hypoxanthine, xanthine, and ATP, and
• b. comparing the measured concentration with a threshold concentration of the one or more purines, wherein the threshold concentration is below about 4 μM and wherein a measured concentration lower than the threshold concentration indicates the absence of an acute cerebral ischaemic disorder.

A method of determining the presence of an acute cerebral ischaemic disorder in a subject, the method comprising:

• measuring the concentration of one or more purines in a body fluid of a subject using a biosensor comprising an electrochemical cell at two or more time points, where the purines are selected from the group consisting of adenosine, inosine, hypoxanthine, xanthine, and ATP, and
• deriving the rate of change of the measured concentration, and
• comparing the rate of change with a threshold value for the rate of change, where a rate of change above the threshold rate of change indicates that the acute ischaemic disorder is present.

A method of determining the presence of an acute cerebral ischaemic disorder in a subject, the method comprising:

• measuring the concentration of one or more purines in a body fluid of the subject using a biosensor comprising an electrochemical cell, where the purines are selected from the group consisting of adenosine, inosine, hypoxanthine, xanthine, and ATP, and
• measuring the rate of change of the concentration of one or more of said purines, and
• using the measured concentration and the measured rate of change to determine the presence of the acute ischaemic disorder in the subject.