Abstract: A method and apparatus including identifying a plurality of at least partially repetitive eye movements of a person, the eye movements defined by a first predominantly horizontal saccadic movement that moves the eye away from a fixation target followed by a corrective saccadic movement towards the target shortly thereafter, measuring a vertical component associated with the plurality of eye movements and comparing the vertical component with a predetermined threshold value.

Abstract: A method and apparatus including identifying a plurality of at least partially repetitive eye movements of a person, the eye movements defined by a first predominantly horizontal saccadic movement that moves the eye away from a fixation target followed by a corrective saccadic movement towards the target shortly thereafter, measuring a vertical component associated with the plurality of eye movements and comparing the vertical component with a predetermined threshold value.

Abstract: A method and apparatus are provided for the differential diagnosis of a patient with progressive supranuclear palsy (PSP) from a patient with Parkinson's disease (PD). One method includes identifying a plurality of partially repetitive eye movements that over time define square wave jerks, each square wave jerk of the plurality of square wave jerks defined by a first horizontal saccadic movement that moves the eye away from a fixation target followed by a corrective saccadic movement towards the target shortly thereafter, measuring a vertical component associated with the plurality of square wave jerks, comparing the vertical component with a threshold value. PSP or PD is identified by comparison of the vertical component with the threshold value. In another embodiment, a patient's saccade rate is determined and compared to a threshold value, and PSP or PD is identified based upon the comparison of the saccade rate with the threshold value.

Abstract: A method and apparatus are provided for characterizing square wave jerks in the eye movements of a person, which may provide a powerful tool in the differential diagnosis of oculomotor and neurological disease. The method includes the steps of a) providing a sequence of saccades, b) identifying pairs of consecutive saccades of the sequence, c) determining whether each saccade of each identified pair is opposite the direction of the other saccade and, if not, then discarding the pair, d) determining whether a magnitude of each saccade of each identified pair is comparable and, if not, then discarding the pair, e) determining whether the pair of saccades of each identified pair are temporally related by a predetermined time period and, if not, then discarding the pair and f) collecting any remaining pairs of saccades as square wave jerks.

Abstract: A method and apparatus are provided for the differential diagnosis of a patient with progressive supranuclear palsy (PSP) from a patient with Parkinson's disease (PD). One method includes identifying a plurality of partially repetitive eye movements that over time define square wave jerks, each square wave jerk of the plurality of square wave jerks defined by a first horizontal saccadic movement that moves the eye away from a fixation target followed by a corrective saccadic movement towards the target shortly thereafter, measuring a vertical component associated with the plurality of square wave jerks, comparing the vertical component with a threshold value. PSP or PD is identified by comparison of the vertical component with the threshold value. In another embodiment, a patient's saccade rate is determined and compared to a threshold value, and PSP or PD is identified based upon the comparison of the saccade rate with the threshold value.

Abstract: A method and apparatus are provided for characterizing square wave jerks in the eye movements of a person, which may provide a powerful tool in the differential diagnosis of oculomotor and neurological disease. The method includes the steps of a) providing a sequence of saccades, b) identifying pairs of consecutive saccades of the sequence, c) determining whether each saccade of each identified pair is opposite the direction of the other saccade and, if not, then discarding the pair, d) determining whether a magnitude of each saccade of each identified pair is comparable and, if not, then discarding the pair, e) determining whether the pair of saccades of each identified pair are temporally related by a predetermined time period and, if not, then discarding the pair and f) collecting any remaining pairs of saccades as square wave jerks.