Functional magnetic resonance imaging study of the brain in patients with amyotrophic lateral sclerosis
Objective:
To study the activation changes of the brain in patients with amyotrophic lateral sclerosis (ALS) while executing sequential finger tapping movement using the method of blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI).
Methods:
Fifteen patients with definite or probable ALS and fifteen age and gender matched normal controls were enrolled. MRI was performed on a 3. 0 Tesla scanner with standard headcoil. The functional images were acquired using a gradient echo single shot echo planar imaging (EPI) sequence. All patients and normal subjects executed sequential finger tapping movement at the frequency of 1-2 Hz during a block-design motor task. Structural MRI was acquired using a three-dimensional fast spoiled gradient echo (3D-FSPGR) sequence. The fMRI data were analyzed by statistical parametric mapping (SPM).
Results:
Bilateral primary sensorimotor cortex (PSM), bilateral premotor area (PA), bilateral supplementary motor area (SMA), bilateral parietal region (PAR), contralateral inferior lateral premotor area (ILPA), and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM, bilateral PA, bilateral SMA, and ipsilateral cerebellum were significantly larger in ALS patients than those in normal controls (P < 0.05). Extra activation areas including ipsilateral ILPA, bilateral posterior limb of internal capsule, and contralateral cerebellum were only detected in ALS patients.
Conclusions:
Similar activation areas are activated in ALS patients and normal subjects while executing the same motor task. The increased activation areas in ALS patients may represent neural reorganization, while the extra activation areas in ALS patients may indicate functional compensation.
