DETECTING A TRANSIENT ISCHEMIC ATTACK USING PHOTOPLETHYSMOGRAM SIGNALS

Systems and methods for detecting an occurrence of a transient ischemic attack (TIA). In one embodiment, a device is utilized to measure first and second signals indicative of photoplethysmogram signals at first and second regions on the left and right sides of a user's head (PPGSL and PPGSR, respectively). A computer detects the occurrence of a TIA based on PPGSL and PPGSR that exhibit a pattern that involves the following: (i) an asymmetry between PPGSL and PPGSR, which is below a threshold, during a first period spanning more than a day; (ii) an asymmetry between PPGSL and PPGSR, which exceeds the threshold, during a second period following the first period and spanning between 5 and 180 minutes; and (iii) an asymmetry between PPGSL and PPGSR, which falls below the threshold, during a third period following the second period.