Plasticity of the Human Motor Cortex in Patients with Arteriovenous Malformations: A Functional MR Imaging Study
Hatem Alkadhia,
Spyros S. Kollias
,a,
Gérard R. Creliera,
Xavier Golaya,
Marie-Claude Hepp-Reymonda and
Anton Valavanisa
a From the Institute of Neuroradiology, University Hospital of Zurich, Switzerland (H.A., S.S.K., G.R.C., X.G., A.V.), and the Institute of Neuroinformatics, University Zurich-Irchel, Switzerland (M-C.H-R.).
View larger version (190K):
[in a new window]
|
FIG 1. Patient 1.
A, Sagittal T1-weighted image (500/14/4) shows the AVM in the left precentral gyrus and central sulcus, thereby involving the expected primary representation area of the left hand.
B and C, Four adjacent axial sections show cortical maps related to finger movements of the left (B) and right (C) hand. Compared with the right hemisphere M1 representation, which is in the expected anatomic location (B), activation in the left hemisphere is displaced laterally. This displacement does not follow the structural distortion of the rolandic region induced by the AVM. Note further activation in bilateral parietal and SMAs.
FIG A1. Plotted signal models of the boxcar functions with different time delays (one, two, and three TRs; upper row), and the trapezoidal function with a one-TR delay and a rise time of two TRs (lower image)
| |
View larger version (267K):
[in a new window]
|
FIG 2. Patient 3.
A, Sagittal T1-weighted image (500/14/4) shows an AVM in the right precentral gyrus, involving the anatomically expected area of hand representation.
B and C, As compared with the unaffected left hemisphere (B), the hand representation in the affected right hemisphere (C) is displaced medially within the precentral gyrus. Additional activation within the ipsilateral M1 is detected. The functional displacement does not follow the structural distortion induced by the underlying disorder. Note additional activation in bilateral supplementary motor (arrows, upper right image in C) and parietal areas.
FIG A2. Patient 1. Reprocessed functional MR imaging experiment using a boxcar function with delays of one TR (upper row), two TRs (middle row), and three TRs (lower row)
| |
View larger version (263K):
[in a new window]
|
FIG 3. Patient 6.
A, Sagittal T1-weighted image (500/14/4) shows the relationship between the left-sided, central AVM and the precentral knob.
B, Movements of the right foot show the expected response in the left paracentral lobule (contralateral M1) with additional activation in bilateral SMAs.
C, Right-hand movements do not elicit activation in M1 but there is prominent signal in bilateral SMAs. Note additional activation in ipsilateral dorsal premotor areas and in the contralateral parietal areas and CMA.
FIG A3. Patient 6. Reprocessed functional MR imaging experiment using a boxcar function with delays of one TR (upper row), two TRs (middle row), and three TRs (lower row)
| |
View larger version (227K):
[in a new window]
|
FIG 4. Patient 7.
A, T1-weighted sagittal image (500/14/4) shows an extensive AVM in the right paracentral lobule extending to the precuneus, thereby involving the expected primary representation of the left foot.
B, Left-hand movements show the expected activation in the contralateral M1.
C, Flexion and extension of the left foot reveal absent contralateral activation but prominent activation in the ipsilateral M1, SMA, dorsal premotor area, and CMA, and in the parietal areas bilaterally.
FIG A4. Reprocessed functional MR imaging experiment using a trapezoidal function with a delay of one TR and a rise time of two TRs in patients 1 (upper row) and 6 (lower row)
| |
