Gaze related enhancement of hemispheric blood flow in a stroke patient.
OBJECTIVE
A patient with a right posterior cerebral artery territory infarction and a left superior quadrantanopia exhibited improvement on various visual tasks including Goldmann perimetry during extreme right gaze. The phenomenon was investigated by functional imaging of cerebral blood flow.


METHODS
[(99m)Tc]HMPAO SPECT was carried out while the patient gazed to the right and to the left at an 8 Hz flash stimulus.


RESULTS
When compared with left gaze, photic stimulation during right gaze was associated with an up to 39.8% increase in regional cerebral blood flow in the damaged right hemisphere, including Brodmann's areas 3-1-2, 7, 21, 22, 39, and 40.


CONCLUSIONS
These gaze related alterations in function and synaptic activity suggest the engagement of a novel arousal-like mechanism that may account in part for comparable findings in patients with neglect and other disorders, and may have relevance to rehabilitation.
Nadeau
S E
SE
Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Medical Center, University of Florida College of Medicine, Gainesville 32608-1197, USA.
Crosson
B
B
Schwartz
R L
RL
Heilman
K M
KM
D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology*; D010775:Photic Stimulation; D012039:Regional Blood Flow; D013702:Temporal Lobe / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon