Blood oxygenation level dependent functional MRI study on the changes of motor cortex in patients with amyotrophic lateral sclerosis / 中华放射学杂志

ABSTRACT

Objective To study the changes of motor cortex in patients with amyotrophic lateral sclerosis(ALS)while executing sequential finger tapping movement by using blood oxygenation level dependent(BOLD)functional MRI.Methods Fifteen patients with definite or probable ALS and 15 age and gender matched normal controls were enrolled in the BOLD study,and all the subjects were right-handed with no other diseases or any recent medication history.A 3.0 T MR scanner was employed and gradient echo EPI(GRE-EPI)sequence was used to acquire the functional images.Subjects executed sequential finger tapping movement at a frequency of 1-2 Hz during a block design task.fMRI data were analyzed by using statistical parametric mapping(SPM)2.Volume of activated brain areas was compared with the use of a Student's t-test.Results Bilateral primary sensorimotor cortex(PSM),bilateral posterior aspect of premotor area(PA),bilateral supplementary motor area(SMA),contralateral inferior lateral premotor area (ILPA),bilateral parietal region(PAR),and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task.The activation areas in bilateral PSM and bilateral posterior aspect of PA(right hand ipsilateral activation:ALS(924.5±141.1)mm3,control(829.9±98.4)mm3,P=0.05;right hand contralateral activation:ALS(9143.8±702.8)mm3,control(8638.8±506.4)mm3,P＜0.05;left hand ipsilateral activation:ALS(1162.5±357.4)mm3,control(902.5±184.2)mm3,P＜0.05;left hand contralateral activation:ALS(8255.2±870.2)mm3,control (5934.6±616.4)mm3,P＜0.05),bilateral SMA(right hand bilateral activation:ALS(6564.3±720.6)mm3,control(4710.7±416.3)mm3,P＜0.05;left hand bilateral activation:ALS(6970.5±961.8)mm3,control(3688.9±672.3)mm3,P＜0.05),and ipsilateral cerebellum(right hand ipsilateral activation:ALS(2720.0±1154.2)mm3,control(254.3±84.4)mm3,P＜0.05;left hand ipsilateral activation:ALS(4794.4±1237.0)mm3,control(1689.0±719.6)mm3,P＜0.05)were significantly larger in ALS patients than in normal controls.Extra activation areas including ipsilateral ILPA,contralateral cerebellum and bilateral posterior limb of internal capsule were only detected in ALS patients.Conclusions Similar activation areas were seen in both groups while executing the same motor task,but the activated areas were more prominent in ALS group.The increased activation areas in ALS patients may represent neural reorganization.while the extra activation areas in ALS patients may indicate functional compensation.