Article Figures & Data
Figures
- Fig 1.
A and B, Functional maps generated from the event-related, visually cued bilateral motor task for a patient with occlusion of the right internal carotid artery. Two axial images are shown with a cross-correlation threshold of r > 0.3. Note that the motor cortex ipsilateral to the lesion (right side) shows minimal or absent activation as a result of the occluded right internal carotid artery (blue circle), a finding corroborated by the blood flow velocity results of the transcranial Doppler US examination.
- Fig 2.
A and B, Functional maps generated from the block motor task for a right internal carotid artery occlusion (same patients as in Figure 1). Two axial images are shown at the same anatomic level as that obtained for the event-related maps in Figure 1, but with a cross-correlation threshold of r > 0.45. Note the strong bilateral activation in the motor cortex.
- Fig 3.
The BOLD signal time courses for a representative patient with an occlusion of the right internal carotid artery (same patients as in Figures 1 and 2). Event-related paradigm curves show the hemodynamic response functions for the right motor cortex (black curve) and left motor cortex (gray curve). The black box denotes the timing of the stimulus (Stim). A decrease in amplitude and delay in onset of the hemodynamic response function exists in the hemisphere ipsilateral to the occlusion (black curve).
Tables
Variable Patient 1 Patient 2 Patient 3 Controls (n=5) Handedness Right Right Left Right Lesion Right ICA occlusion Left ICA occlusion Left MCA 70% stenosis None Perfusion results Arterial spin labeling (%) −27 −13 −19 R>L 3.3 +/− 2.5 TCD acetazolamide challenge (L/R) 100/24% 3.7/4.5 ARI 11/60% NA Event-related experiment % BOLD change (L/R) 1.2/0.79* 0.89/0.73 1.22/1.62* 1.12/1.26 Time to peak (L/R in sec) 8.1/11* 13/8.5* 7.9/7.3 7.5/7.5 Extent (L>R or R>L) L≫R R≫L R>L Same Block experiment % BOLD change (L/R) 2.3/1.53* 0.93/1.1 1.35/3.3* 2.35/2.17 Extent (L>R or R>L) Same Same R>L Same Note.—ICA indicates internal carotid artery; MCA, middle cerebral artery; TCD, transcranial Doppler US; ARI, autoregulatory index; NA, not available; L, left; R, right.
TCD and arterial spin labeling perfusion results for the patients are relative to baseline and normal hemisphere, respectively; for control subjects, arterial spin labeling results are referenced to the right hemisphere. The BOLD signal change and time to peak were measured for the average hemodynamic response. The extent of the functional maps was determined qualitatively.
* Statistical significance of P < .01.
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