Corticospinal Tract Fibers Research Articles

Reorganization of corticospinal tract fibers after spinal cord injury in macaques

Reorganization of corticospinal tract fibers after spinal cord injury in macaques

Functional Recovery of Carbon Nanotube/Nafion Nanocomposite in Rat Model of Spinal Cord Injury

Background Acute spinal cord injury (ASCI) can lead to paraplegia or quadriplegia, the treatment of which has been a major problem. New therapeutic approaches in developing carbon nanotubes (CNT) functionalized with the Nafion nanocomposite, a sulfonated tetrafluoroethylene copolymer, have been shown to increase the length of selected neurites in vitro. Objective We hypothesized that the administration of the CNT/Nafion nanocomposite after experimental SCI will promote regeneration of axons into the lesion cavity and the functional recovery of the hind limbs in a rat model. Methods To evaluate this hypothesis through this experimental research paper, transection SCI was induced at the T9-T10 vertebral level in adult female rats. One week after transection, the epicenter of the lesion was injected with 25 lL of vehicle (saline), or 1 lg/mL, 10 lg/mL, or 100 lg/mL of CNT/Nafion nanocomposite. Behavioral analysis was carried out by assessing tail flick, chronic pain or mechanical allodynia, motor coordination, and the results of the rotarod test performed pre- and post-surgery, on days 3, 7, 14, 21 and 28, using the tail flick analysis, Noldus CatWalk gait analysis, open-field locomotor test, and Rotarod test. At 28 days post-injection, the rats were euthanized and spinal cord tissue was extracted. Results We found that post-SCI, administration of the CNT/Nafion nanocomposite resulted in decreased lesion volume, increased neurofilament-positive fibers and corticospinal tract fibers in the lesion, and no increase in reactive gliosis (P < 0.001). Additionally, post-SCI administration of CNT/Nafion nanocomposite induced a modest improvement in hind limb locomotor recovery without inducing hyperalgesia. Conclusion These data suggest that the CNT/Nafion nanocomposite may be an effective material to promote axonal repair and regeneration after SCI.

Short pulse width widens the therapeutic window of subthalamic neurostimulation

We explored the impact of pulse durations <60 μsec on the therapeutic window of subthalamic neurostimulation in Parkinson's disease. Current thresholds for full rigidity control and first muscle contractions were evaluated at pulse durations between 20 and 120 μsec during a monopolar review session in four patients. The average therapeutic window was 2.16 mA at 60 μsec, which proportionally increased by 182% at 30 μsec, while decreasing by 46% at 120 μsec. Measured chronaxies and model data suggest, that pulse durations <60 μsec lead to a focusing of the neurostimulation effect on smaller diameter axons close to the electrode while avoiding stimulation of distant pyramidal tract fibers.

Pure Motor Monoparesis in the Upper Extremity Due to a Medial Medullary Infarction

A 69-year-old man with essential hypertension abruptly presented with moderate pure motor monoparesis (PMM) in the left-sided upper extremity. There were no other neurologic abnormalities. Cranial magnetic resonance imaging demonstrated a small infarction in the caudal and lateral region of the right-sided medial medulla oblongata. Thereafter, intravenous anti-thrombin agent was initiated, and she became asymptomatic within 14 days. This is a first reported case of PMM in the upper extremity due to medial medullary infarction (MMI). In the medulla oblongata, we speculated that the corticospinal tract fibers innervating the lower extremity might decussate rostral to the fibers innervating the upper extremity. J Med Cases. 2015;6(1):8-9 doi: http://dx.doi.org/10.14740/jmc1989w

Pure Motor Monoparesis in the Upper Extremity Due to a Medial Medullary Infarction

A 69-year-old man with essential hypertension abruptly presented with moderate pure motor monoparesis (PMM) in the left-sided upper extremity. There were no other neurologic abnormalities. Cranial magnetic resonance imaging demonstrated a small infarction in the caudal and lateral region of the right-sided medial medulla oblongata. Thereafter, intravenous anti-thrombin agent was initiated, and she became asymptomatic within 14 days. This is a first reported case of PMM in the upper extremity due to medial medullary infarction (MMI). In the medulla oblongata, we speculated that the corticospinal tract fibers innervating the lower extremity might decussate rostral to the fibers innervating the upper extremity. J Med Cases. 2015;6(1):8-9 doi: http://dx.doi.org/10.14740/jmc1989w

Millard-Gubler Syndrome: A Case Report

Rebleeding, cerebral vasospasm, hydrocephalus, seizures, cardiopulmonary complications, hypertension, urinary, and fecal incontinence, electrolyte and fluid imbalance are frequently encountered complications of aneurysm, surgical, and endovascular treatment of aneurysm. Neurological deficits secondary to surgery or endovascular coiling are also among these complications. Millard-Gubler Syndrome develops as a result of injury or infarction of the pons at the level of the facial nerve nucleus.In this syndrome facial nerve nucleus, the abducent nerve, and the opposite corticospinal tract fibers are involved. This report describes a patient presenting with severe headache, and generalized seizure to our intensive care unit. Cranial computed tomography was performed and revealed on subarachnoid hemorrhage. After the aneurysm of the left posterior communicating artery was detected in the radiology department, the patient underwent clipping operation in our department the next day. The patient had no neurological deficits after microsurgical clipping treatment till the third postoperative day when sudden right peripheral facial paralysis and diplopia (double vision) developed which was associated with left side hemiparesis, i.e, the right (opposite side of aneurysm). This right-sided Millard-Gubler Syndrome which has not been cited in the literature so far was reported by us.

HMG-CoA Reductase Inhibition Promotes Neurological Recovery, Peri-Lesional Tissue Remodeling, and Contralesional Pyramidal Tract Plasticity after Focal Cerebral Ischemia.

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are widely used for secondary stroke prevention. Besides their lipid-lowering activity, pleiotropic effects on neuronal survival, angiogenesis, and neurogenesis have been described. In view of these observations, we were interested whether HMG-CoA reductase inhibition in the post-acute stroke phase promotes neurological recovery, peri-lesional, and contralesional neuronal plasticity. We examined effects of the HMG-CoA reductase inhibitor rosuvastatin (0.2 or 2.0 mg/kg/day i.c.v.), administered starting 3 days after 30 min of middle cerebral artery occlusion for 30 days. Here, we show that rosuvastatin treatment significantly increased the grip strength and motor coordination of animals, promoted exploration behavior, and reduced anxiety. It was associated with structural remodeling of peri-lesional brain tissue, reflected by increased neuronal survival, enhanced capillary density, and reduced striatal and corpus callosum atrophy. Increased sprouting of contralesional pyramidal tract fibers crossing the midline in order to innervate the ipsilesional red nucleus was noticed in rosuvastatin compared with vehicle-treated mice, as shown by anterograde tract tracing experiments. Western blot analysis revealed that the abundance of HMG-CoA reductase was increased in the contralesional hemisphere at 14 and 28 days post-ischemia. Our data support the idea that HMG-CoA reductase inhibition promotes brain remodeling and plasticity far beyond the acute stroke phase, resulting in neurological recovery.

Aging of corticospinal tract fibers according to the cerebral origin in the human brain: A diffusion tensor imaging study

The corticospinal tract (CST) is known to originate from multiple cerebral areas, including the primary motor cortex (M1). In this study, using diffusion tensor imaging (DTI), we attempted to investigate the differences of aging of CST fibers according to the cerebral origin in the human brain. Sixty healthy subjects aged from the 20s to the 70s were recruited, and 10 subjects were assigned to each age group. CST fibers were reconstructed from the M1 (Broadmann’s area [BA] 4), the secondary motor area (M2, BA 6), and the primary somatosensory cortex (S1, BA 1–3), respectively. Values of fractional anisotropy (FA), mean diffusivity (MD), and tract volume (TV) of CST fibers from each cerebral area were measured. Significant differences in the TV values of CST fibers from the M2 were observed between the 70s age group and the other age groups, except the 60s age group (p<0.05). However, no significant difference in the values of FA and MD of CST fibers from the M2 were observed between age group (p>0.05). No significant differences in the values of FA, MD, and TV of CST fibers from the S1 and M1 were observed between age groups (p>0.05). We found that the fiber number of CST fibers from the M2 was decreased in the 70s age group compared with the 20s–50s age groups. Because the main function of the M2 is motor planning and coordination, our results would be helpful in development of strategies for coping with aging of the CST.

Comparison of Olfactory Bulbar and Mucosal Cultures in a Rat Rhizotomy Model

In an ongoing clinical trial, a spinal injured patient who received a transplant of autologous cells cultured from the olfactory bulb is showing greater functional benefit than three previous patients with transplants of mucosal origin. Previous laboratory studies of transplantation into rat spinal cord injuries show that the superior reparative benefits of bulbar over mucosal cultures are associated with regeneration of severed corticospinal tract fibers over a bridge of olfactory ensheathing cells (OECs) formed across the injury site. In a rat rhizotomy paradigm, we reported that transplantation of bulbar cell cultures also enables severed axons of the C6-T1 dorsal roots to regenerate across a bridge of OECs into the spinal cord and restore electrophysiological transmission and forepaw grasping during a climbing test. We now report a repeat of the same rhizotomy procedure in 25 rats receiving cells cultured from olfactory mucosal biopsies. In no case did the transplanted cells form a bridging pathway. No axons crossed from the severed roots to the spinal cord, and there was no restoration of forepaw grasping. This suggests that the superior clinical benefit in the patient receiving bulbar cell transplants is due to regeneration of severed fibers across the injury site, and this correlates with imaging and the pattern of functional recovery. Using present culture protocols, the yield of OECs from bulbar biopsies is around 50%, but that from mucosal biopsies is less than 5%. Improving the yield of OECs from mucosal biopsies might avoid the necessity for the intracranial approach to obtain bulbar cells.

Role of CSPG receptor LAR phosphatase in restricting axon regeneration after CNS injury

Extracellular matrix molecule chondroitin sulfate proteoglycans (CSPGs) are highly upregulated in scar tissues and form a potent chemical barrier for CNS axon regeneration. Recent studies support that the receptor protein tyrosine phosphatase σ (PTPσ) and its subfamily member leukocyte common antigen related phosphatase (LAR) act as transmembrane receptors to mediate CSPG inhibition. PTPσ deficiency increased regrowth of ascending axons into scar tissues and descending corticospinal tract (CST) axons into the caudal spinal cord after spinal cord injury (SCI). Pharmacological LAR inhibition enhanced serotonergic axon growth in SCI mice. However, transgenic LAR deletion on axon growth in vivo and the role of LAR in regulating regrowth of other fiber tracts have not been studied. Here, we studied the role of LAR in restricting regrowth of injured descending CNS axons in deficient mice. LAR deletion increased regrowth of serotonergic axons into scar tissues and caudal spinal cord after dorsal over-hemitransection. LAR deletion also stimulated regrowth of CST fibers into the caudal spinal cord. LAR protein was upregulated days to weeks after injury and co-localized to serotonergic and CST axons. Moreover, LAR deletion improved functional recovery by increasing BMS locomotor scores and stride length and reducing grid walk errors. This is the first transgenic study that demonstrates the crucial role of LAR in restricting regrowth of injured CNS axons.

Successful excision of a pontomesencephalic cavernoma through anterior subtemporal route without mapping: Anatomical landmarks as a road map

Successful excision of a pontomesencephalic cavernoma through anterior subtemporal route without mapping: Anatomical landmarks as a road map

Preoperative weakness and demyelination of the corticospinal tract in meningioma patients : changes in diffusion parameters using diffusion tensor imaging.

ObjectiveDifferentiation of demyelination in white matter from axonal damage can be determined using diffusion tensor imaging (DTI). In this study using meningioma patients an attempt was made to evaluate the relationship between preoperative weakness and the changes of diffusion parameters in the corticospinal tract (CST) using DTI.MethodsTwenty-six patients with meningioma were enrolled in this study. Eleven of them suffered from objective motor weakness and were classified as Group 1. The remaining 15 patients did not present motor weakness and were classified as Group 2. Fiber tractography and CST diffusion parameters were obtained using DTIStudio. The ratios (lesion side mean value/contralateral side mean value) of CST diffusion parameters were compared with 1.0 as a test value using a one-sample t-test.ResultsIn Group 1, fractional anisotropy (FA), tensor trace (TT), and radial diffusivity (RD, λ2 and λ3) of the CST were significantly different between two hemispheres, but axial diffusivity (AD, λ1) of the CST was not significantly different between two hemispheres. In Group 2, FA and λ3 of CST did not differ significantly between the hemispheres. In Group 2, TT, λ1, and λ2 of CST in the ipsilateral hemisphere were significantly higher than those of the unaffected hemisphere. However, the differences were small.ConclusionMotor weakness was related to a low FA and high TT resulting from increased RD of the CST fibers. CST diffusion changes in patients with weakness are similar to those for demyelination.

Rewiring of the corticospinal tract in the adult rat after unilateral stroke and anti-Nogo-A therapy

Adult Long Evans rats received a photothrombotic stroke that destroyed >90% of the sensorimotor cortex unilaterally; they were subsequently treated intrathecally for 2 weeks with a function blocking antibody against the neurite growth inhibitory central nervous system protein Nogo-A. Fine motor control of skilled forelimb grasping improved to 65% of intact baseline performance in the anti-Nogo-A treated rats, whereas control antibody treated animals recovered to only 20% of baseline scores. Bilateral retrograde tract tracing with two different tracers from the intact and the denervated side of the cervical spinal cord, at different time points post-lesion, indicated that the intact corticospinal tract had extensively sprouted across the midline into the denervated spinal hemicord. The original axonal arbours of corticospinal tract fibres that had recrossed the midline were subsequently withdrawn, leading to a complete side-switch in the projection of a subpopulation of contralesional corticospinal tract axons. Anterograde tracing from the contralesional cortex showed a 2-3-fold increase of midline crossing fibres and additionally a massive sprouting of the pre-existing ipsilateral ventral corticospinal tract fibres throughout the entire cervical enlargement of the anti-Nogo-A antibody-treated rats compared to the control group. The laminar distribution pattern of the ipsilaterally projecting corticospinal tract fibres was similar to that in the intact spinal cord. These plastic changes were paralleled by a somatotopic reorganization of the contralesional motor cortex where the formation of an ipsilaterally projecting forelimb area was observed. Intracortical microstimulation of the contralesional motor cortex revealed that low threshold currents evoked ipsilateral movements and electromyography responses at frequent cortical sites in the anti-Nogo-A, but not in the control antibody-treated animals. Subsequent transection of the spared corticospinal tract in chronically recovered animals, treated with anti-Nogo-A, led to a reappearance of the initial lesion deficit observed after the stroke lesion. These results demonstrate a somatotopic side switch anatomically and functionally in the projection of adult corticospinal neurons, induced by the destruction of one sensorimotor cortex and the neutralization of the CNS growth inhibitory protein Nogo-A.

Diffusion tensor and volumetric magnetic resonance imaging using an MR-compatible hand-induced robotic device suggests training-induced neuroplasticity in patients with chronic stroke

Stroke is the third leading cause of mortality and a frequent cause of long-term adult impairment. Improved strategies to enhance motor function in individuals with chronic disability from stroke are thus required. Post-stroke therapy may improve rehabilitation and reduce long-term disability; however, objective methods for evaluating the specific impact of rehabilitation are rare. Brain imaging studies on patients with chronic stroke have shown evidence for reorganization of areas showing functional plasticity after a stroke. In this study, we hypothesized that brain mapping using a novel magnetic resonance (MR)-compatible hand device in conjunction with state-of-the-art magnetic resonance imaging (MRI) can serve as a novel biomarker for brain plasticity induced by rehabilitative motor training in patients with chronic stroke. This hypothesis is based on the premises that robotic devices, by stimulating brain plasticity, can assist in restoring movement compromised by stroke-induced pathological changes in the brain and that these changes can then be monitored by advanced MRI. We serially examined 15 healthy controls and 4 patients with chronic stroke. We employed a combination of diffusion tensor imaging (DTI) and volumetric MRI using a 3-tesla (3T) MRI system using a 12-channel Siemens Tim coil and a novel MR-compatible hand-induced robotic device. DTI data revealed that the number of fibers and the average tract length significantly increased after 8 weeks of hand training by 110% and 64%, respectively (p<0.001). New corticospinal tract (CST) fibers projecting progressively closer to the motor cortex appeared during training. Volumetric data analysis showed a statistically significant increase in the cortical thickness of the ventral postcentral gyrus areas of patients after training relative to pre-training cortical thickness (p<0.001). We suggest that rehabilitation is possible for a longer period of time after stroke than previously thought, showing that structural plasticity is possible even after 6 months due to retained neuroplasticity. Our study is an example of personalized medicine using advanced neuroimaging methods in conjunction with robotics in the molecular medicine era.

Corticospinal tract sprouting in the injured rat spinal cord stimulated by Schwann cell preconditioning of the motor cortex

Peripheral nerve preconditioning lesions have been shown to consistently enhance sensory nerve regeneration in the injured spinal cord.Objective: The aim of this study was to determine if the rat motor cortex could be preconditioned through the implantation of Schwann cells (SC), thereby stimulating sprouting and regeneration of the corticospinal tract (CST).Methods: Schwann cells (cultured in vitro) were injected into the motor cortex and seven days post-surgery rats underwent a dorsal spinal hemisection injury. Eight weeks following spinal injury animals were perfused and the CST visualised by Avidin-peroxidase histochemistry for dextran-biotin.Results: Results demonstrate substantially enhanced CST collateral sprouting in both the rostral grey and white matter of the injured spinal cord in animals with SC implanted into the motor cortex compared to control animals with and without cortical vehicle injections. Corticospinal tract peri-wound regenerative sprouting was also enhanced in animals implanted with cortical SC compared to controls, however, only a small degree of CST axonal regeneration was present in the grey matter beneath the injury site. In all groups, CST peri-lesional regenerative sprouting occurred in close proximity to macrophages. Complicated and intimate relationships between CST fibres and these cells were evident.Discussion: Overall, our data demonstrates that preconditioning the motor cortex with SC prior to spinal injury results in greatly enhanced CST sprouting and that CST peri-wound sprouting takes place in juxtaposition to macrophages.

P 189. The extent of perifocal edema in function associated motor fibers correlates to the primary motor deficit in patients with M1-adjacent intracerebral tumors. A volumetric analysis of presurgically acquired data based on MRI, FET-PET and navigated TMS on primary motor functions

Question Many patients with brain tumors adjacent to the primary motor (M1) region initially present with transient or permanent motor deficits. Factors like compression by tumor mass, tumor infiltration, as well as the extent of the perifocal edema might contribute to the motor deficit. In order to assess the relevance of these factors, we analyzed the spatial relationship between M1 cortical representation assessed with navigated transcranial magnetic stimulation (nTMS) and the anatomical and metabolic extension of tumors in the M1 region in patients prior to surgery. Methods To date, 21 patients with M1-adjacent tumors (glioblastoma ( n = 14), anaplastic astrocytoma ( n = 1), carcinoma metastasis ( n = 4), anaplastic ependymoma ( n = 1), lymphoma ( n = 1)) underwent an anatomical MRI protocol including a T2-weighted sequence, a gadolinium-contrast-enhanced sequence (GCE) and diffused tensor imaging as well as 18F-fluoroethyl-L-tyrosine (FET) PET for presurgical planning. Cortical M1 representations for the hand, foot and tongue were assessed by nTMS within 7 days. “Functional” fiber tracking of the corticospinal tract (CST) consisted of the following processing steps: (1) setting the seed points defined by the coordinate revealing the highest motor evoked potential (MEP) when stimulated by nTMS at 110% of the resting motor threshold and the surrounding 5 mm, according to the registration and E-field calculation mismatch and (2) a seed volume at the midbrain level. Total volumes and intersection volumes of the CST and the anatomically defined areas were expressed in cm 3 ±standard deviation (SD). Results 15 out of the 21 patients had a primary motor deficit recorded in either the upper or lower limb, the facial muscles or initially presented with a hemiparesis, 6 patients had not developed any deficit prior to or at admission to surgery. Neither the GCE ( p = .96) nor the FET ( p = .45) tumor volume statistically differed between the group of patients with a motor deficit (GCE: 19.7 ± 17.2 cm 3 ; FET: 9.6 ± 5.3 cm 3 , n = 15) compared to one without a motor deficit (GCE: 12.1 ± 16.8 cm 3 ; 6.4 ± 6.5 cm 3 , n = 6). The mean perifocal edema volume based on the T2-weighted MRI data was slightly greater in the motor deficit group (64.2 ± 38.1 cm 3 ) than in the group of patients without any motor deficit (43.4 ± 28.6 cm 3 ) but did again not pass the statistical threshold ( p = .37). However, the mean relative volume of functional fibers intersected by the T2-weighted edema volume was statistically greater in the primary motor deficit group (16.1 ± 13.1%) than in the one without motor deficits (0.1 ± 0.0%). By contrast, the mean relative volume of cortical M1 representation intersected by the edematous area did not statistically differ between the two groups ( p = .09). Nor the mean relative volume of functional fibers or functional motor cortex intersected by GCE or PET tumor volumes were statistically different between the two groups. Likewise, neither the mean absolute volume of supratentorial functional fibers nor of the cortical M1 representation volumes differed between the two groups. Conclusion The study implicates that neither direct tumor infiltration of the M1 region or the CST nor the tumor volume nor the extension of perifocal edema in total may be the main causes for the primary motor deficit of brain tumor patients at initial presentation. In contrast, the extent of the perifocal edema affecting CST fibers seems to be responsible for motor deficits prior to surgery.

The role of diffusion tensor imaging in evaluating the motor outcome and life quality of patients with brain insula-basal ganglia gliomas

Objective To investigate the application value of a new parameter of diffusion tensor imaging(DTI)-the relative effective fibers of pyramidal tract (rEPT) in evaluation of motor outcome in combination with life quality of patients with brain insula-basal ganglia (IBG) gliomas.Methods Diffusion tensor imaging (DTI) was pre-and postoperatively performed on 14 patients,the DTI data was transport into DTI studio software to reconstruct bilateral pyramidal tract and calculate rEPT value at the tumor side (rEPTt).Spearman's rank correlation method was used to elucidate the relationship between rEPTt value and motor outcome as well as KPS.Moreover the paired t-test was employed to analyze the difference of rEPTt value at 3 different phases of preoperation,short-term and long-term postoperation.Results There were significant positive correlations between rEPTt value and motor outcome as well as KPS (P ＜ 0.001); there were significant differences between preoperative rEPTt value (0.7754-0.0232),short-term postoperative rEPTt value (0.7197 ± 0.0423) and long-term postoperative rEPTt value (0.9280 ± 0.0231) (P ＜ 0.01).The long-term postoperative rEPTt was significantly higher than the preoperative and the short-term postoperative rEPTt value.Conclusion rEPTt value is useful in evaluating the rehabilitated condition of patients with IBG gliomas at the early stage; the gradually recovery process of patient's neurological function can be reflected by the change of pre-and postoperative rEPTt values. Key words: Diffusion tensor imaging; Glioma ; Pyramidal tract ; Insula ; Basal ganglia

STAT3 promotes corticospinal remodelling and functional recovery after spinal cord injury

If and how neurons remodel their connections after CNS injury critically influences recovery of function. Here, we investigate the role of the growth-initiating transcription factor STAT3 during remodelling of the injured corticospinal tract (CST). Endogenous STAT3 expression in lesioned cortical projection neurons is transient but can be sustained by viral gene transfer. Sustained activation of STAT3 enhances remodelling of lesioned CST fibres and induces de novo formation of collaterals from unlesioned CST fibres. In a unilateral pyramidotomy paradigm, this recruitment of unlesioned fibres leads to the formation of midline crossing circuits that establish ipsilateral forelimb activation and functional recovery.

P45 Forms a Complex with FADD and Promotes Neuronal Cell Survival Following Spinal Cord Injury

Fas-associated death domain (DD) adaptor (FADD), a member of the DD superfamily, contains both a DD and a death effector domain (DED) that are important in mediating FAS ligand-induced apoptotic signaling. P45 is a unique member of the DD superfamily in that it has a domain with sequence and structural characteristics of both DD and DED. We show that p45 forms a complex with FADD and diminishes Fas-FADD mediated death signaling. The DED of FADD is required for the complex formation with p45. Following spinal cord injury, transgenic mice over-expressing p45 exhibit increased neuronal survival, decreased retraction of corticospinal tract fibers and improved functional recovery. Understanding p45-mediated cellular and molecular mechanisms may provide insights into facilitating nerve regeneration in humans.

Automatic detection of primary motor areas using diffusion MRI tractography: Comparison with functional MRI and electrical stimulation mapping

As an alternative tool to identify cortical motor areas for planning surgical resection in children with focal epilepsy, the present study proposed a maximum a posteriori probability (MAP) classification of corticospinal tract (CST) visualized by diffusion MR tractography. Diffusion-weighted imaging (DWI) was performed in 17 normally developing children and 20 children with focal epilepsy. An independent component analysis tractography combined with ball-stick model was performed to identify unique CST pathways originating from mouth/lip, finger, and leg areas determined by functional magnetic resonance imaging (fMRI) in healthy children and electrical stimulation mapping (ESM) in children with epilepsy. Group analyses were performed to construct stereotaxic probability maps of primary motor pathways connecting precentral gyrus and posterior limb of internal capsule, and then utilized to design a novel MAP classifier that can sort individual CST fibers associated with three classes of interest: mouth/lip, fingers, and leg. A systematic leave-one-out approach was applied to train an optimal classifier. A match was considered to occur if classified fibers contacted or surrounded true areas localized by fMRI and ESM. It was found that the DWI-MAP provided high accuracy for the CST fibers terminating in proximity to the localization of fMRI/ESM: 78%/77% for mouth/lip, 77%/76% for fingers, 78%/86% for leg (contact), and 93%/89% for mouth/lip, 91%/89% for fingers, and 92%/88% for leg (surrounded within 2 cm). This study provides preliminary evidence that in the absence of fMRI and ESM data, the DWI-MAP approach can effectively retrieve the locations of cortical motor areas and underlying CST courses for planning epilepsy surgery.