The Study Of Motor Cortical Reorganization After Nerve Transfer In Patients With Brachial Plexus Injury By Using Functional Magnetic Resonance Imaging

[Abstract] Purpose: To apply functional magnetic resonance imaging to map the somatotopic organization of the primary and nonprimary motor cortex and cerebellum by using voluntary movements of the hand, elbow, and the foot of both of the extremity , and to analyze extent of activation and signal intensity ? To evaluate the value of fMRI in mapping whole brain of the simple motor of limbs . Materials and methods: 10 healthy right handedness volunteers were employed in this study. Motor task consisted of repetitive simple movements of the hands.elbows and foots. fMRI examinations were performed with superconduct 3.0T MR scanner and echo-planer imaging sequence was used. The maps of the most significant voxel of activation area in the whole brain motor related structures was recorded and the statistic analysis of variance was used for values of size and signal intensiy as well as the axis of the Talairach coordinates. Results: In all subjects, The significient activation was predominantly in the contralateral motor areas include primary sensorimotor cortex, lateral premotor, parietal and supplementary motor areas and ipsilateral cerebellum. While the nonprimary motor areas were activated to be more extensive and to be seen in more subjects during the non-dominant hand task than during dominant hand task.Statically significant MR signal changes were observed within contralateral primary motor cortex in all subjects and movement conditions. The pattern of functional activity in M1 and cerebellum lateral regions followed a topographic representation: hand , Elbow, foot movements activated area located in order。 Statistic analysis indicated that there were significant differences between both hands. Conclusions: fMRI is capable of mapping of the motor cortex in different tasks in subjects. It is logical that for most right-handed individuals, simple movements of the left hand are less familiar, more complex and require more conscious effort, resulting in recruitment of additional motor areas than same tasks with the right hand.These observations may be useful in studying motor reorganization . fMRI can provide various information on functional brain research .Part IIThe study of motor cortical organization related with virtual movement task inpatients suffered from peripheral nerve jnjury and the healthy by usingfunctional magnetic resonance imagingAbstract Objective To map motor cortex organization in the patients suffered from totally brachial plexus avulsions and amputee and the healthy.To preliminary explore the feature of activiation induced with mentally simulated movement .and to evaluate the value of virtual movement in the peripheral nerve injury rehabilitation by using fMRI.MATERIALS and METHODS Eight patients with traumatic root avulsions of the brachial plexus prior to nerve transfer surgery and four amputee and four normal persons were studied.Maps of neural activity within the motor cortex were generated for both "hand" flexion and extension with mentally simulated movement in each patient by using BOLD-fMRl.The location of activiation were measured in the Talarich coordinates.Both the number of active pixels and the signal changing amplitude in region of interest(ROI) were counted with AFNI software.The different people fMRI data were divided into four groups: group A is collected during the healthy virtual mevement; group B are patients with brachial plexus avulision scanned prior to the surgery . group C means amputee virtually move the hand amputated.and group D are the normal contral group to move hand really. ANOVA and Student-Newman-Keuls test were applied to compare the difference between the four groups either the number of active pixels and the mean value of intensity of primary motor cortex.RESULTS (1)The mean value of activation differed in the four groups.The difference is significient between A and D,B and D,C and D.While A ,C and C shows no significient difference between each other.That means the intensity of real movement are stronger than virtual movement. (2)The number of activated pixels differed in the four groups. The difference is significient between A and D,B and D,C and D.While A ,C and C shows no significient difference between each other.That means the extent of real movement is larger than virtual movement., (3)The virtual movement activiate more areas in the non-primary motor cortex and in theA B C groups than in the D groups. However it did not appear to differ betweenA ,C and B groups. CONCLUSIONS (1)Activation of the virtual movement in diffent people can be reflected on fMRI. (2)The significantly activiate areas induced by virtual movement locate in the non-M1 motor related regions .which are just contrast to the real movement. ?Mentally simulated movement can be acted as a valuable method for the recovery exercise with peripheral nerve injury. PART IIIThe study of motor cortical reorganization \n patients suffered from totallybrachial plexus avulsion treated with phrenic nerve to musculocutaneous nervetransfer by using functional magnetic resonance imagingAbstract Objective To map reorganization in the primary motor cortex occur after a PN-MCN transfer in patients suffered from totally brachial plexus avulsion.To preliminary explore the underlying mechanism in the plascity changes.and to evaluate the value of fMRI in the peripheral nerve injury rehabilitation.MATERIALS and METHODS Eight patients with traumatic root avulsions of the brachial plexus were studied prior to nerve transfer surgery and as well as in early and end stage post operation.Maps of neural activity within the motor cortex were generated for both arms in each patient with biceps contraction by using fMRI.The location of activiation were measured in the Talarich coordinates.Both the number of active pixels and the signal changing amplitude were counted with AFNI software.The different period fMRI data were divided into four groups: group A is collected prior to the surgery; group B is scanned at the early stage post operation when the biceps contraction can only be effected by means of a voluntary respiratory effort, group C means volition control over biceps contraction can be achieved without resorting to respiratory effort.and group D are the normal contral group. ANOVA and Student-Newman-Keuls test were applied to compare the difference between the four groups either the number of active pixels and the mean value of intensity of primarymotor cortex.RESULTS (1)The value of activation differed in the four groups.The difference is significient between A and B,B and C,B and D.While C and D shows no significient difference.That means the intensity becomes more stronger after nerve transfer. (2)The number of activated pixels differed in the four groups.The difference is significient between A and B, C,D.While B, C and D shows no significient fifference between each other.That indicates the extent becomes larger after nerve transfer. (3) The weighted center of gravity is distributed irregular in the B groups. However it did not appear to differ between C and D groups. CONCLUSIONS (1)Re—activation of the neural input activation for volition biceps control after PN-MCN transfer is reflected on fMRI. (2)The significantly activiate area induce by affected biceps contraction returns to the "initial homeland". (3)fMRI can provide a valuable tool for the judgment of the effect of rehabilitation with peripheral nerve injury.PART IVThe study of motor cortical reorganization in patients with total brachial plexus avulsion underwent cervical 7 nerve root of unaffected side to affected median nerve transfer by using functional magnetic resonance imagingAbstract Objective To map reorganization in the primary motor cortex occur after an unaffected C7 to affected side median nerve transfer in patients suffered from totally brachial plexus avulsion.To preliminary explore the underlying mechanism in the placsity changes.and to evaluate the value of fMRI in the peripheral nerve injury rehabilitation.MATERIALS and METHODS 25 patients with traumatic root avulsions of the brachial plexus were studied prior to nerve transfer surgery and as well as in early and stable stage post operation.Maps of neural activity within the both side primary motor cortex were generated for both arms in each patient with hand and wrist contraction by using fMRI.The location of activiation were measured in the Talarich coordinates.Both the number of active pixels and the signal changing amplitude were counted with AFNI software.The different period fMRI data were divided into four groups: group A is collected prior to the surgery; group B is scanned...