Corticospinal tract recovery in a patient with traumatic transtentorial herniation

Transtentorial herniation is one of the causes of motor weakness in traumatic brain injury. In this study, we report on a patient who underwent decompressive craniectomy due to traumatic intracerebral hemorrhage. Brain CT images taken after surgery showed intracerebral hemorrhage in the left fronto-temporal lobe and left transtentorial herniation. The patient presented with severe paralysis of the right extremities at the time of intracerebral hemorrhage onset, but the limb motor function recovered partially at 6 months after onset and to nearly normal level at 27 months. Through diffusion tensor tractography, the left corticospinal tract was disrupted below the cerebral peduncle at 1 month after onset and the disrupted left corticospinal tract was reconstructed at 27 months. These findings suggest that recovery of limb motor function in a patient with traumatic transtentorial herniation can come to be true by recovery of corticospinal tract.     

Delayed gait recovery in a stroke patient

We report on a stroke patient who showed delayed gait recovery between 8 and 11 months after the onset of intracerebral hemorrhage. This 32-year-old female patient underwent craniotomy and drainage for right intracerebral hemorrhage due to rupture of an arteriovenous malformation. Brain MR images revealed a large leukomalactic lesion in the right fronto-parietal cortex. Diffusion tensor tractography at 8 months after onset revealed that the right corticospinal tract was severely injured. At this time, the patient could not stand or walk despite undergoing rehabilitation from 2 months after onset. It was believed that severe spasticity of the left leg and right ankle was largely responsible, and thus, antispastic drugs, antispastic procedures (alcohol neurolysis of the motor branch of the tibial nerve and an intramuscular alcohol wash of both tibialis posterior muscles) and physical therapy were tried to control the spasticity. These measures relieved the severe spasticity, with the result that the patient was able to stand at 3 months. In addition, the improvements in sensorimotor function, visuospatial function, and cognition also seemed to contribute to gait recovery. As a result, she gained the ability to walk independently on even floor with a left ankle foot orthosis at 11 months after onset. This case illustrates that clinicians should attempt to find the cause of gait inability and to initiate intensive rehabilitation in stroke patients who cannot walk at 3-6 months after onset.     

Ipsilateral motor pathway without contralateral motor pathway in a stroke patient

The ipsilateral motor pathway from the unaffected motor cortex to the affected extremity is one of the mechanisms of motor recovery following stroke. We report on a stroke patient who showed the ipsilateral motor pathway without the contralateral motor pathway on functional MRI and diffusion tensor tractography. A 53-year-old left hemiparetic patient with an infarct in the right middle cerebral artery territory was evaluated. During a period of three months after onset, motor function of the affected (left) hand had recovered slowly, to the extent that the patient was able to overcome gravity. FMRI showed that only the unaffected (left) primary sensorimotor cortex was activated by movements of the unaffected (right) hand or of the affected (left) hand. On diffusion tensor tractography, the corticospinal tract of the left hemisphere originated from the primary sensori-motor cortex and descended through the known corticospinal tract pathway. By contrast, the right corticospinal tract showed a disruption with Wallerian degeneration to the upper medulla. We conclude that the motor function of the affected (left) hand appeared to be controlled only by the ipsilateral motor pathway from the left motor cortex to the left hand. Motor function of the affected hand appeared to have been reorganized to the ipsilateral motor pathway from the unaffected motor cortex to the affected hand.     

弥散张量纤维束成像和经颅磁刺激显现脑出血患者独立的皮质脊髓束

Diffusion tensor tractography allows visualization of the corticospinal tract (CST) in three dimensions. Transcranial magnetic stimulation offers a unique advantage in that it can distinguish between the corticospinal tract and the non-CST by analyzing the characteristics of a motor-evoked potential. A 15 year-old female showed right hemiparesis, due to intracerebral hemorrhage in the left corona radiata, and the posterior limb of the internal capsule. Diffusion tensor tractography revealed that the tracts of both hemispheres originated from the precentral gyrus, and descended through the known CST pathway. Specifically, the tract of the affected hemisphere descended through an isolated area in the leukomalactic lesion at the posterior limb level. In addition, the characteristics of the motor-evoked potential obtained from the right hand when stimulating the hot spot of the left motor cortex corresponded to a CST. In conclusion, we report on a patient with intracerebral hemorrhage who showed an isolated CST in a leukomalactic lesion. This result suggests the importance of saving the adjacent area or penumbra around a hematoma after an intracerebral hemorrhage.     

Transcallosal motor pathway from affected motor cortex to affected hand in a patient with corona radiata infarct A diffusion tensor tractography and transcranial magnetic stimulation study

The mechanisms of motor recovery through the transcallosal pathway remain poorly understood.The present study reports on a hemiplegic patient with corona radiata infarct; it attempts to confirm motor recovery through the transcallosal motor pathway, from the affected motor cortex to the affected hand, using diffusion tensor tractography and transcranial magnetic stimulation. A 54-year-old, male patient and eight age-matched, normal subjects were enrolled in the study. The patient's right hand was initially completely paralyzed, but slowly recovered over 6 months. In the control subjects and the unaffected hemisphere (right) of the patient, the corticospinal tracts originated from the motor cortex and descended along the known corticospinal tract pathway.However, the corticospinal tract of the affected hemisphere was disrupted at the upper pons.Following transcranial stimulation of the affected (left) motor cortex, motor evoked potential from the affected (right) abductor pollicis brevis muscle exhibited longer latency than opposite motor evoked potential. Results from the present study suggest that motor function of the affected (right) hand recovered via the transcallosal motor pathway from the affected (left) motor cortex in this patient.     

Spared integrity of corticospinal tract within a pontine infarct A diffusion tensor tractography study

Integrity of the corticospinal tract is mandatory for good recovery of impaired motor function in patients who have suffered a stroke. A 67-year-old left hemiparetic female showed an infarct in the right pons. Three months after onset, motor function of the affected extremities recovered rapidly to a nearly complete state. Diffusion tensor tractography of both hemispheres showed that the corticospinal tract originated from the primary sensori-motor cortex and descended through the known corticospinal tract ...     

磁共振弥散张量成像在基底节区高血压脑出血致皮质脊髓束损伤中的应用研究

目的 探讨磁共振弥散张量成像(DTI)技术评价基底节区高血压脑出血(HICH)患者皮质脊髓束(CST)受损程度的意义及其与肌力恢复的关系.方法 徐州医学院附属医院神经外科自2006年11月至2009年5月行小骨窗开颅血肿清除术治疗单侧基底节区HICH患者35例,术后10 d应用3.0T磁共振DTI技术检测患者和10例健康志愿者CST,应用Functool软件进行图像分析观察CST损伤程度,HICH患者康复治疗2月后采用Brunnstrom标准进行肢体肌力检查,分析CST损伤程度与肢体肌力的相关性.结果 10例健康志愿者CST显示清晰.35例HICH患者CST受损的模式有3种:纤维束显示达正常侧的2/3或相仿(11例),患者肢体肌力恢复最好;纤维束显示小于正常侧的2/3(18例),患者肢体肌力恢复较好;纤维柬显示小于正常侧的1/3(6例),患者肢体肌力恢复最差.CST受损患者患侧的FA值均较健侧降低,差异有统计学意义(P<0.05).3种模式CST损伤患者患侧的FA值、肢体肌力不同,差异均有统计学意义(P=0.000).患者CST损伤程度与肌力恢复水平存在负相关关系(r=0.931,P=0.000).结论 应用磁共振DTI技术可显示脑内白质纤维束的走形及分布,能够早期检测HICH患者CST的损伤程度,对患者肢体运动功能损伤的评估、判断预后有重要的临床意义.     

Recovery of the corticospinal tract after injury by transtentorial herniation: a case report

Little is known about recovery of the corticospinal tract (CST) after injury by transtentorial herniation (TH). We present with a patient who showed recovery of the CST after injury by TH, using diffusion tensor tractography (DTT) and transcranial magnetic stimulation (TMS). A 69-year-old female underwent craniotomy and drainage of an intracerebral hemorrhage in the left corona radiata and basal ganglia. Brain CT showed left TH and brain MRI revealed a leukomalactic lesion at the left cerebral peduncle. The patient presented with complete paralysis of the right extremities at ICH onset, but slowly recovered some function to the point of being able to move the affected extremities against gravity at about 6 months after onset. Three-week DTT showed disruption of the left CST below the cerebral peduncle; however, this disruption was recovered on 1-year DTT. Three-week TMS showed no motor evoked potential for the affected hemisphere; in contrast, motor evoked potentials that were compatible with regenerated CST were obtained from the affected hand muscle at 6 months. Using DTT and TMS in a patient with ICH, we demonstrated recovery of the CST after injury by TH.     

Motor recovery via aberrant pyramidal tract in a patient with traumatic brain injury A diffusion tensor tractography study

The aberrant pyramidal tract is the collateral pathway of the pyramidal tract through the medial lemniscus in the brainstem. A 21-year-old man presented with right hemiparesis due to a traumatic intracerebral hemorrhage in the left corona radiata. His motor function recovered almost to the normal state at 10 months after onset. Through diffusion tensor tractography, the pyramidal tract in the affected (left) hemisphere showed discontinuation at the pontine level at 13 months after onset. An aberrant pyramidal tract was observed, which originated from the primary motor cortex and the supplementary motor area and descended through the corona radiata, then through the posterior limb of the internal capsule and the medial lemniscus pathway from the midbrain to the pons, finally entered into the pyramidal tract area at the pontomedullary junction. It suggests that the motor functions of the right extremities in this patient had recovered by this aberrant pyramidal tract.     

延髓锥体梗死患者运动功能恢复与皮质脊髓束穿行于梗死延髓锥体的小块空余区

The present study reported a 58-year-old male patient who exhibited complete paralysis of the right extremities at stroke onset.Brain MR images showed an infarct in the left medullary pyramid and a small spared area on the medial side of the infarct.He gained the ability to extend the affected fingers against gravity and to dorsiflex the affected ankle without gravity at 3 months after stroke onset.Diffusion tensor imaging results showed that at 6 months after stroke onset,the corticospinal tract of the affected(left) hemisphere descended through the small spared area of the infarcted medullary pyramid.No motor-evoked potential was elicited from the affected(left) hemisphere at 2 weeks after stroke onset;however,motor-evoked potential was elicited at 6 months as shown by transcranial magnetic stimulation results.The motor function of the affected side of this patient appears to have been recovered via the corticospinal tract that passed through the small spared area within the infarcted medullary pyramid.     

功能MRI和弥散张量纤维束示踪成像联合应用是评估脑出血患者躯体感觉功能恢复的有用工具？1例报告

研究背景：目前对中风之后的身体感觉机能障碍了解很少。 研究目的：我们试图证明应用功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT)能使颅内出血(ICH)患者的身体感觉机能障碍康复。 研究设计,时间和地点：从2008年6月到11月在理疗与康复教研室进行病例研究。 参与人员：55岁的女患者,她起先右侧皮质和辐射冠自发性的颅内出血,造成左身严重的身体感觉机能障碍。 研究方法：应用PHILIPS公司Gyroscan Intera 1 .5 T扩散张量纤维束示踪系统和磁共振成像系统从开始之后的3-7周进行两个纵向评估。扩散张量纤维束示踪以分次的各向异性<0.2作为最终标准,磁共振成像通过手的触摸和被动运动来完成. 主要成果: 我们发现扩散张量纤维束示踪过程和磁共振成像上的皮质激活是伴随着身体感觉功能的恢复一起的. 研究结果: 受作用的一边在开始之后的第7周身体感觉功能会恢复到接近于正常的状态.从第3到7周的功能性磁共振成像上我们发现, 位于另一侧初级感觉皮质中心的皮质被活化.然而,在第3周的磁共振成像上却没有发生皮质激活功能而被动运动的激活功能在第7周比第3周显示的有所增强.在第3周对受创一侧(右侧)扩散张量纤维束示踪中我们没能发现内侧丘系.第7周的内侧丘系示踪, 一个内侧丘系沿着丘系内侧从辐射冠上升到初级感觉皮质. 结论: 我们证明了在这位患者的身体感觉机能恢复中应用到了功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT). 我们推断在研究中风病人的身体感觉机能障碍的康复中功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT)是有效的方法.     

Motor recovery via aberrant pyramidal tract in a patient with a cerebral peduncle infarct*●

The presence of the aberrant pyramidal tract has been demonstrated by several studies;however,little is known about its role in motor recovery in stroke patients.In the present study,we reported a 69-year-old right-handed female patient with an infarct in the mid to lateral portion of the left cerebral peduncle,who showed an aberrant pyramidal tract by diffusion tensor tractography.The patient presented with severe weakness of the right extremities at stroke onset.The patient showed progressive motor recovery as much as being able to extend the affected extremities against some resistance at 6 months after onset.At 20 months after stroke onset,motor function of the left extremities had recovered to a nearly normal state.Diffusion tensor tractography results showed that the PT was disrupted at the lower midbrain of the affected(left) hemisphere at 3 weeks after stroke onset and this disruption was not changed at 20 months.An aberrant pyramidal tract in the left hemisphere was also observed,which originated from the primary motor cortex and descended through the corona radiata,posterior limb of the internal capsule,thalamus,the medial lemniscus pathway from the midbrain to the pons,and then entered into the pyramidal tract area at the pontomedullary junction.Transcranial magnetic stimulation did not elicit motor evoked potential from the affected hand muscle at 3 weeks,but it elicited motor evoked potential with mildly delayed latency and low amplitude in the affected hand muscle at 20 months.The main motor functions of the affected extremities in this patient appeared to be recovered via this aberrant pyramidal tract.     

The effect of continuous theta burst stimulation over premotor cortex on circuits in primary motor cortex and spinal cord

ObjectiveTo understand the effect of continuous theta burst stimulation (cTBS) given to the premotor area, we studied the circuits within the primary motor cortex and spinal cord after cTBS over the dorsal premotor area (PMd).MethodsThree sets of parameters, including corticospinal excitability, short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) and forearm reciprocal inhibition (RI) were tested.ResultsParalleling the effects of cTBS applied directly to the primary motor cortex, cTBS over the left PMd suppressed corticospinal excitability as measured by the change in the size of MEPs evoked by single pulse TMS over primary motor cortex. Premotor cTBS appeared to have a longer lasting, but no more powerful effect on corticospinal excitability than motor cTBS, however, unlike motor cTBS it had no effect on SICI or ICF. Finally, although premotor cTBS had no effect on spinal H-reflexes, it did reduce the third phase of RI between forearm extensor and flexor muscles.ConclusionsPremotor cTBS is a quick and useful way of modulating excitability in cortical and possibly subcortical motor circuits.SignificancePremotor cTBS can be used as an alternative to regular rTMS to evaluate cortical function, motor behaviours and the response to disease therapy.     

Cortical reorganization demonstrated by diffusion tensor tractography analyzed using functional MRI activation

The diffusion tensor tractography (DTT) allows the corticospinal tract(CST) to be visualized at the subcortical level and functional MRI (fMRI) is capable of precisely identifying activation sites at the cortex. Therefore, it seems that combined DTT/fMRI would allow more accurate evaluation of the state of the CST. We have attempted to demonstrate cortical reorganization in a patient with cortical hemorrhage using DTT analyzed by fMRI activations. Six normal subjects and a 12-year-old female patient with a hemorrhage in the left fronto-parietal cortex were recruited. fMRI was performed at 1.5-T with timed hand grasp-release movements, and DTT was performed using 1.5-T with a Synergy-L Sensitivity Encoding head coil. Three-dimensional reconstructions of the fiber tracts were obtained using the fMRI activation as the seed region of interest and the CST area of the anterior pons as the target region of interest. The tract of the affected hemisphere originated from the lateral area of the injured precentral knob and descended along the known corticospinal tract pathway. It seems that the motor function of the affected hand was reorganized into the lateral area of the injured precentral knob. Therefore, these combined modalities would be helpful in elucidating the state of the CST.     

A review of motor recovery mechanisms in patients with stroke

Elucidation of the motor recovery mechanisms in stroke patients is important because such information could provide the scientific basis for stroke rehabilitation. The motor recovery mechanism after stroke, however, has not yet been clearly elucidated, but several suggested mechanisms have been proposed. These include the ipsilateral motor pathway from the unaffected motor cortex to the affected hand, peri-lesional reorganization, the recovery of a damaged lateral corticospinal tract, and contribution of the secondary motor area. Additionally, little is known about the motor recovery mechanism for patients with intracerebral hemorrhage, for locomotor recovery, and for damage at the subcortical level. Therefore, we suggest that further research should be focused on the elucidation of motor recovery mechanisms in relation to the above topics. In the current study, we tried to review the literatures about the motor recovery mechanisms of the patients with stroke.     

大脑中动脉梗死患者运动功能的恢复与脉络丛前动脉供血脑区有关？

no chinese abstract     

Is combined functional magnetic resonance imaging and diffusion tensor tractography a useful tool for evaluation of somatosensory dysfunction recovery after intracerebral hemorrhage?

Diffusion tensor tractography allows the sensory fiber course of the medial lemniscus to be visualized. But diffusion tensor tractography for accurate evaluation of the repair of injured somatosensory tracts in stroke patients has been rarely reported. A 55-year-old female patient presented with severe somatosensory dysfunction of the left side caused by a spontaneous intracerebral hemorrhage on the right side. The somatosensory function of the affected side recovered to a nearly normal state at 7 weeks from onset. Functional magnetic resonance imaging revealed that at 3 weeks from onset, there was no cortical activation by touch at each hand; at 7 weeks, the contralateral cortex centered on the primary sensory cortex was found to be activated during touch and passive movements, and activation by passive movements was increased compared with that at 3 weeks. Diffusion tensor tractography revealed that a medial lemniscus on the affected (right) hemisphere was not observed at 3 weeks from onset, however, at 7 weeks, the unaffected (left) hemisphere passed along the medial lemniscus pathway from the pons to the primary sensory cortex. These findings indicate that combined functional magnetic resonance imaging and diffusion tensor tractography would allow more accurate evaluation of the architecture and integrity of somatosensory tracts and is a useful method to investigate the recovery of somatosensory dysfunction in stroke patients.     

Aberrant pyramidal tract in a patient with corona radiata infarct A diffusion tensor tractography study

The aberrant pyramidal tract refers to the collateral pathway of the pyramidal tract through the medial lemniscus in the brainstem.A 63-year-old male patient presented with severe paralysis of the left extremities due to a right corona radiata infarct.He was able to extend the affected fingers against resistance at 2 months after stroke onset.At 6 months after stroke onset,he was able to perform some fine motor activities,as well as to walk with a nearly normal gait.Functional MRI,which was performed at 6 months after onset,showed that the contralateral primary sensorimotor cortex was activated during affected(left) hand movements.Diffusion tensor tractography results showed that at 2 weeks after stroke onset,pyramidal tracts of the affected hemisphere originated from the primary motor cortex and descended along the known pathway of the pyramidal tract with an aberrant pyramidal tract,which was bypassed through the medial lemniscus from the midbrain to the lower pons.However,the pyramidal tract from midbrain to pons in the affected hemisphere could not be depicted by diffusion tensor tractography at 6 months after stroke onset;instead,only the aberrant pyramidal tract existed for the course of the disappeared pyramidal tract.Results from this study indicate that the main motor functions of the affected extremities appeared to be controlled via the aberrant pyramidal tract with degeneration of the pyramidal tract in the brainstem of the affected hemisphere.     

Comprehensive analysis of area‐specific and time‐dependent changes in gene expression in the motor cortex of macaque monkeys during recovery from spinal cord injury

The present study aimed to assess the molecular bases of cortical compensatory mechanisms following spinal cord injury in primates. To accomplish this, comprehensive changes in gene expression were investigated in the bilateral primary motor cortex (M1), dorsal premotor cortex (PMd), and ventral premotor cortex (PMv) after a unilateral lesion of the lateral corticospinal tract (l‐CST). At 2 weeks after the lesion, a large number of genes exhibited altered expression levels in the contralesional M1, which is directly linked to the lesioned l‐CST. Gene ontology and network analyses indicated that these changes in gene expression are involved in the atrophy and plasticity changes observed in neurons. Orchestrated gene expression changes were present when behavioral recovery was attained 3 months after the lesion, particularly among the bilateral premotor areas, and a large number of these genes are involved in plasticity. Moreover, several genes abundantly expressed in M1 of intact monkeys were upregulated in both the PMd and PMv after the l‐CST lesion. These area‐specific and time‐dependent changes in gene expression may underlie the molecular mechanisms of functional recovery following a lesion of the l‐CST.     

硬脑膜下血肿清除前后皮质脊髓束的状态：弥散张量成像证据

Abstract Subdural hematoma can cause compression or damage to the neural tracts in the brain; however, very little is known about this injury. We report on a patient with subdural hematoma who was evaluated by diffusion tensor imaging prior to and after trephination and drainage of subdural hematoma. A 58-year-old male patient and ten age-matched normal control subjects were evaluated. The patient showed mild hemiparesis for 3 weeks prior to surgery. His hemiparesis recovered to a nearly normal state at 5 weeks post-surgery when the follow up diffusion tensor image was acquired. Two diffusion tensor image parameters, fractional anisotropy and apparent diffusion coefficient, were measured along the corticospinal tract. Pre-operative diffusion tensor image showed that the corticospinal tract of the affected hemisphere seemed to be injured or compressed. However, the follow up diffusion tensor image showed recovery of this corticospinal tract to a normal state. It would appear that diffusion tensor images are a useful tool for evaluation of the effects of subdural hematomas on neural tracts. Key Words: subdural hematoma; diffusion tensor imaging; hemiparesis; corticospinal tract