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.     

Kernohan's notch phenomenon demonstrated by diffusion tensor imaging and transcranial magnetic stimulation

Kernohan's notch phenomenon is the ipsilateral hemiplegia caused by compression of the contralateral cerebral peduncle against the tentorial edge by a supratentorial mass. Diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS) could be useful for exploring the state of the corticospinal tract (CST). This report attempts to demonstrate Kernohan's notch phenomenon in a patient with subdural haematoma by using DTI and TMS. One patient and six normal control subjects were recruited. The patient showed severe right hemiplegia even though the subdural haematoma was located in the right hemisphere. Brain CT at the time of onset showed right transtentorial herniation, and T2 weighted images at 6 weeks after onset showed a leucomalacic lesion on the left cerebral peduncle. DTI and TMS were performed at 6 weeks after onset. The fractional anisotrophy value of the left midbrain and medulla of the patient was found to be decreased in comparison with that of the control subjects. On fibre tractography for the CST, an interruption was observed in the left midbrain and medulla. The motor evoked potential obtained from the right hand muscle showed delayed latency, low amplitude and a higher excitatory threshold, thus indicating that the CST of the left hemisphere had been damaged. It seems that the CST had been damaged at the left midbrain, although subdural haematoma and transtentorial herniation had occurred in the right hemisphere in this patient. This report demonstrates Kernohan's notch phenomenon in this patient using DTI and TMS.     

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.     

Motor recovery mechanism in a quadriplegic patient with locked-in syndrome

Locked-in syndrome (LIS) is a rare neurologic condition caused by bilateral pontine lesions. Quadriplegia is one of the most serious clinical manifestations in patients with LIS. However, little is known about the motor recovery mechanism of quadriplegia in patients with LIS. In the current study, we present with a quadriplegic patient with bilateral pontine infarcts, whose motor function appeared to be reorganized into the peri-infarct areas of the infarcted pons, as demonstrated by diffusion tensor tractography (DTT). A 60-year-old was diagnosed as LIS due to bilateral pontine infarcts 6 years ago. The patient presented with complete paralysis of all four extremities at onset. After slow motor recovery, the patient was able to move all joint muscles against gravity and demonstrated some fine motor activity at the time of DTT scanning (6 years after onset). Results of DTTs for the corticospinal tract (CST) in both hemispheres showed that the CSTs originated from the primary motor cortex, descended along the known CST pathway, and passed through lateral areas of infarcts in the pons. Therefore, motor function of the four extremities of this patient appears to have been recovered by the CST, which passed through the lateral areas to the pontine infarcts.     

Prognostic factors for motor outcome in patients with compressed corticospinal tract by intracerebral hematoma

Little is known about prognostic factors associated with motor outcome when the corticospinal tract (CST) was compressed by hematoma. Using diffusion tensor tractography (DTT), we attempted to investigate prognostic factors for motor outcome in patients whose affected CST was compressed by hematoma. The study included 51 consecutive severe hemiparetic patients with a hematoma involving the corona radiata and basal ganglia. Integrities of the affected CSTs were preserved to the cerebral cortex and were found to be compressed by a hematoma on DTT. Patients were classified into four groups according to the region which the CST was originated from the precentral gyrus (type A), postcentral gyrus (type B), posterior parietal cortex (type C), and premotor cortex (type D). We measured the ratios of DTT parameters between affected/unaffected hemispheres.The motor function of the affected extremities at 6-month after onset was better with the following order: DTT type A, type B, type C, and type D patients. The 6-month motor function for DTT type A patients was higher than that of DTT type D patients (p=0.008). The fractional anisotropy ratio between the affected and unaffected CST was positively correlated with the 6-month motor function of the affected extremities (Pearson's correlation coefficient, p=0.025, r=0.313). We found that motor outcome differed according to the originated area of the affected CST and the degree of injury of the affected CST in patients whose affected CST was compressed by hematoma.     

Why do stroke patients with negative motor evoked potential show poor limb motor function recovery？

Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral pe-duncle area on the affected side, but the characteristics of these changes have not been reported. This study included 57 cases of cerebral infarction whose motor evoked potentials were tested in the 24 hours after the first inspection for diffusion tensor imaging, in which 29 cases were in the negative group and 28 cases in the positive group. Twenty-nine patients with negative motor evoked potentials were divided into two groups according to fractional anisotropy on the affected side of the cerebral peduncle： a fractional anisotropy 〈 0.36 group and a fractional anisotropy 〉 0.36 group. All patients underwent a regular magnetic resonance imaging and a diffusion tensor imaging examina- tion at 1 week, 1, 3, 6 and 12 months after cerebral infarction. The FugI-Meyer scores of their hemiplegic limbs were tested before the magnetic resonance and diffusion tensor imaging exami-nations. In the negative motor evoked potential group, fractional anisotropy in the affected cerebral peduncle declined progressively, which was most obvious in the first 1-3 months after the onset of cerebral infarction. The areas and area asymmetries of the cerebral peduncle on the affected side were significantly decreased at 6 and 12 months after onset. At 12 months after onset, the area asymmetries of the cerebral peduncle on the affected side were lower than the normal lower limit value of 0.83. FugI-Meyer scores in the fractional anisotropy ≥0.36 group were significantly higher than in the fractional anisotropy 〈 0.36 group at 3-12 months after onset. The fractional anisotropy of the cerebral peduncle in the positive motor evoked potential group decreased in the first 1 month after onset, and stayed unchanged from 3-12 months; there was no change in the area of the cerebral peduncle in the first 1-12 months after cerebral infarction. These findings confirmed that if the fractional anisotropy of the cerebral peduncle on the affected side is 〈 0.36 and the area asym-metries 〈 0.83 in patients with negative motor evoked potential after cerebral infarction, then poor hemiplegic limb motor function recovery may occur.     

Motor outcome of deep intracerebral haemorrhage in diffusion tensor imaging: comparison of data from different locations along the corticospinal tract

Abstract

Objectives:

Although diffusion tensor imaging (DTI) is widely studied to assess the motor outcome after ischaemic stroke, there is paucity of data regarding outcomes of intracerebral haemorrhage (ICH). The aim of this study was to determine the DTI data from different locations along the corticospinal tract (CST) and association to motor outcome.

Methods:

We prospectively recruited patients with deep ICH admitted to our hospital from November 2010 to July 2012.Diffusion tensor imaging was performed within 14?days after the onset of ICH. Fractional anisotropy (FA) was measured along the CST at corona radiata, perihaematomal oedema, cerebral peduncle and pons. Corticospinal tract integrity was classified into three types by diffusion tensor tractography (DTT): type A with preserved CST, type B with partially interrupted CST and type C with completely interrupted CST. Motor outcome was assessed by Motricity index (MI) at admission, after 1 and 3?months.

Results:

Forty-eight patients were enrolled with a mean age of 62?years. The median time interval from onset of ICH to DTI study was 7?days. The patients in type C had significantly worse MI at admission (P?<?0.001), after 1?month (P?<?0.001) and after 3?months (P?<?0.001) as compared to those with type A and type B. Lower rFA at the corona radiata was significantly correlated with poorer motor outcome at admission, after 1?month and after 3?months.

Discussion:

Clinical motor outcome of ICH within 2?weeks can be identified with a statistically significant decrease in rFA at the corona radiata.     

Diffusion tensor imaging for measuring recovery from cerebellar peduncle injury due to intracerebral hemorrhage A case report

Diffusion tensor tractography (DTT) in diffusion tensor imaging (DTI) examination allows for the three-dimensional visualization of cerebellar peduncles. The present case-control study analyzed the relationship between functional recovery of intracerebral hematoma patient and cerebellar peduncle injury, as detected by DTI. The enrolled patient could not sit at 3 weeks after onset, but was able to walk independently and perform most daily activities after 4 months. The 3-week DTT images revealed that all six cerebellar peduncles were compressed by the hematoma, posterior portions of all three left cerebellar peduncles were shortened, and the left middle cerebellar peduncle was interrupted in the mid-portion. The 4-week DTT images showed that all compressed cerebellar peduncles were ameliorated, although injured posterior portions of the three left cerebellar peduncles did not recover. The fractional anisotropy value of the right inferior cerebellar peduncle increased from two standard deviations below the normal control value to within two standard deviations of the normal control value. These findings suggested that functional recovery was primarily due to decompression of compressed cerebellar peduncles, and not to recovery of injured cerebellar peduncles. DTI evaluations of cerebellar peduncles could be helpful when cerebellar peduncle injury is suspected.     

Injury of fornix in patients with intracerebral hemorrhage

ABSTRACT Objectives: Many diffusion tensor tractography (DTT) studies have reported on fornix injury in various diseases. However, there has been no DTT study on fornix injury by intracerebral hemorrhage (ICH). We attempted to investigate fornix body injury in patients with ICH, using DTT. Methods: We identified 58 consecutive stroke patients using the following criteria: (1) first-ever stroke, (2) age: 45-65 years, (3) hemorrhage confined within the corona radiata and basal ganglion level, (4) an available DTT scan performed during the early stage of ICH (1-5 weeks after onset). Among 58 consecutive patients, we identified six patients who showed disruption at the fornix body.Results: Following ICH, 10.7% of patients revealed complete disruption of the fornix body on DTT. Results from DTT of the fornix showed disruption in anterior and posterior portions of the fornix body in three patients, in the anterior portion of the fornix body in two patient, and in the posterior portion of the fornix body in one patient. Conclusions: We report on six patients who showed complete disruption of the fornix body following ICH. It is our belief that the fornix of patients with ICH could be evaluated using DTT.     

Effects of minimally invasive techniques for evacuation of hematoma in basal ganglia on cortical spinal tract from patients with spontaneous hemorrhage: observed by diffusion tensor imaging

Abstract

Objective: To observe the effect of minimally invasive removal of intracranial hematoma in basal ganglia on cortical spinal tract (CST).

Methods: Twenty-seven patients with intracerebral hemorrhage (ICH) in basal ganglia were selected and divided into a minimally invasive treatment group (13 patients) and a medical treatment group (14 patients) randomly: the volume of hematoma was 30–50 ml, with an average of 39.20 ± 4.85 ml in minimally invasive group and 38.70 ± 6.33 ml in medical treatment group. All patients underwent the whole brain diffusion tensor imaging (DTI) in 1 week after onset; fractional anistropy (FA) values of CST in internal capsule and cerebral peduncle ipsilateral and contralateral to the hematoma side in minimally invasive group were determined and then compared with those in medical treatment group.

Results: The minimally invasive treatment group showed that FA values of CST in internal capsule and cerebral peduncle on the affected side were 0.524 ± 0.045 and 0.534 ± 0.020, respectively, and in medical treatment group, FA values were 0.425 ± 0.050 and 0.468 ± 0.040, respectively. FA values of internal capsule and cerebral peduncle CST in minimally invasive treatment group were significantly increased as compared with the medical treatment group, and a significant difference was noted. In minimally invasive group, we obtained pre-operative DTI in five patients; FA values of CST in internal capsule and cerebral peduncle ipsilateral to the hemorrhage side were 0.428 ± 0.032 and 0.515 ± 0.048, respectively, 1 week after the hematoma was evacuated FA values of CST in internal capsule and cerebral peduncle increased significantly. Therefore, minimally invasive surgery for evacuation of intracranial hematomas could reduce the damages to CST. At the same time, the CST which was oppressed and displaced by hematoma restored to normal position largely or completely after the minimally invasive removal of intracranial hematoma.

Conclusions: The changes of CST could be visualized by DTI in patients with ICH. Minimally invasive removal of intracranial hematoma could effectively reduce the injury to the CST and could restore the CST which was oppressed and displaced by the hematoma to the normal position.     

Demonstration of Recovery of a Patient with a Cerebellar Peduncle Injury due to Intracerebral Hemorrhage: a Diffusion Tensor Imaging Study.

背景：扩散张量成像可以对小脑脚进行三维显影。 目的：采用扩散张量成像,观察一位由于颅内出血所致小脑脚损伤患者在三个月内的功能恢复。 设计,时间和地点：病例研究,2008年10月至2009年3月期间在岭南大学医学院理疗康复教研室进行。 受试者：一位72岁女性患者,九名对照者,对照者同患者的年龄和性别相符。 方法：采用1.5T敏感性编码头线圈进行扩散张量成像。 主要观察指标：采用DTI-Studio软件评价小脑脚,包括小脑上脚,小脑中脚和小脑下脚。 结果：患者在发病三周后不能平坐,但可以独立行走,发病后4周可以完成大部分日常活动。3周扩散张量成像显示,所有小脑脚被血肿压迫。左小脑脚的后侧缩短,尤其是左小脑中脚在中部阻断。4月扩散张量成像显示,所有被压缩的小脑脚复原。此外,3周扩散张量成像结果还显示,除去右小脑中脚之外,所有小脑脚的各项异性值同正常对照值相比,降低了2个标准差。4月扩散张量成像结果显示,右小脑小脚的各项异性值有所增加,比正常对照值高出2个标准差。尽管如此,其他小脑脚的各项异性值仍保持在正常对照值之下的2个标准差。结果显示,发病后3周时的小脑脚的神经元损伤（所有小脑上脚,左小脑中脚和所有小脑下脚）在发病后4月内康复不明显。 结论：患者的功能性恢复最初是由于被压迫的小脑脚的减压所致,而不是受伤小脑脚的恢复。笔者认为采用扩散张量成像评价小脑脚对小脚损伤的疑似病例有帮助。     

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.     

A change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex in a patient with intracerebral hemorrhage

Many studies have attempted to elucidate the motor recovery mechanism of stroke,but the majority of these studies focus on cerebral infarct and relatively little is known about the motor recovery mechanism of intracerebral hemorrhage.In this study,we report on a patient with intracerebral hemorrhage who displayed a change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex on diffusion tensor imaging.An 86-year-old woman presented with complete paralysis of the right extremities following spontaneous intracerebral hemorrhage in the left frontoparietal cortex.The patient showed motor recovery,to the extent of being able to extend affected fingers against gravity and to walk independently on even ground at 5 months after onset.Diffusion tensor imaging showed that the left corticospinal tract originated from the premotor cortex at 1 month after intracerebral hemorrhage and from the left primary motor cortex and premotor cortex at 5 months after intracerebral hemorrhage.The change of injured corticospinal tract originating from the premotor cortex to the primary motor cortex suggests motor recovery of intracerebral hemorrhage.     

扩散张量成像技术对急性脑梗死的诊断价值

目的应用MR扩散张量成像(DTI)及扩散张量纤维束成像(DTT)技术对急性脑梗死患者进行检查,研究患者肢体活动障碍的表现及预后与皮质脊髓束的关系及ADC图对急性脑梗死的诊断价值。方法对33例急性脑梗死患者(发病时间<72h)行常规MRI检查及DTI检查,并进行皮质脊髓束三维DTT成像及b=1000的ADC成像,将患者运动障碍的程度分为无瘫痪,治疗后瘫痪恢复,治疗后瘫痪不恢复3种情况,将常规MRI图、DTI中的ADC图影像表现及DTT图皮质脊髓束形态表现与患者临床肌力表现及治疗结果相比较。结果无瘫痪13例,治疗后瘫痪恢复者9例,治疗后瘫痪不恢复者11例,DTT图显示皮质脊髓束分别为无受压,受压无中断及中断破坏。所有病例ADC图均表现为低或稍低信号。结论DTI及DTT技术,对判断脑梗死患者运动障碍的程度及预后有重要价值。     

内囊后肢梗死患者皮质脊髓束的重组

Several diffusion tensor-imaging studies have demonstrated motor recovery mechanisms in stroke patients with subcortical infarct,including the corona radiata,pons,and medulla.However,studies of motor recovery mechanisms have not been reported in patients with posterior limb infarcts of the internal capsule.The present study reports on a 77-year-old man with complete paralysis of the left extremities at stroke onset.At 6 months after onset,motor function of the left extremities recovered to a nearly normal state.The 3-week diffusion tensor tractography of the affected(right) hemisphere showed that corticospinal tract discontinued below the posterior limb.In contrast,6-month diffusion tensor tractography revealed that the right corticospinal tract originated from the precentral gyrus and descended along the anterior area of the infarcted posterior limb.Motor function of the affected extremities was reorganized into the anterior area of the posterior limb infarct.     

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     

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.     

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.     

Brain functional reorganization in children with hemiplegic cerebral palsy: Assessment with TMS and therapeutic perspectives

Transcranial magnetic stimulation (TMS) can be a useful tool for the assessment of the brain functional reorganization in subjects with hemiplegic cerebral palsy (HCP). In this review, we performed a systematic search of all studies using TMS in order to explore the neuroplastic changes that occur in HCP patients. We aimed at investigating the usefulness of TMS to explore cortical excitability, plasticity and connectivity changes in HCP. Children with HCP due to unilateral lesions of the corticospinal system had ipsilateral motor evoked potentials (MEPs) similar to those recorded contralaterally. TMS studies demonstrated that occupational and constraint-induced movement therapy were associated with significant improvements in contralateral and ipsilateral corticomotor projection patterns. In addition, after intensive bimanual therapy, children with HCP showed increased activation and size of the motor areas controlling the affected hand. A TMS mapping study revealed a mediolateral location of the upper and lower extremity map motor cortical representations. Deficits in intracortical and interhemispheric inhibitory mechanisms were observed in HCP. Early hand function impairment correlated with the extension of brain damage, number of involved areas, and radiological signs of corticospinal tract (CST) degeneration. Clinical mirror movements (MMs) correlated with disability and CST organization in subjects with HCP and a positive relationship was found between MMs and MEPs strength. Therefore, TMS studies have shed light on important pathophysiological aspects of motor cortex and CST reorganization in HCP patients. Furthermore, repetitive TMS (rTMS) might have therapeutic effects on CST activities, functional connectivity and clinical status in children with HCP.     

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 ...