Prediction of motor outcome based on diffusion tensor tractography findings in thalamic hemorrhage

A prospective study of MRI biomarkers in the brain and lower limb muscles for prediction of lower limb motor recovery following stroke

The aim of this prospective observational longitudinal study was to explore and decipher the predictive value of prospective MRI biomarkers in the brain and lower limb muscles for 3-month lower limb motor recovery following stroke. In the brain, we measured the integrity of the corticospinal tract (fractional anisotropy/"FA"). In the muscles, we measured volume, fatty replacement (fat fraction analysis and proton spectroscopy) and oedema. Measurements were taken at two time points: (1) within 4 weeks of stroke (baseline measurement, clinical and imaging) and (2) 3 months following stroke (follow up measurement, clinical only). Clinical measurements consisted of assessments of functional ability and strength (Fugl-Meyer score, motor NIHSS, Functional Ambulation Category/"FAC", and muscle dynamometry). Twenty-three patients completed imaging and clinical assessments at baseline and follow-up; five patients had partial imaging assessment. The results provided some evidence that damage to the corticospinal tract would result in less motor recovery: recovery of the Fugl-Meyer score and dynamometric ankle plantarflexion, ankle dorsiflexion, and knee extension correlated positively and significantly with fractional anisotropy (0.406-0.457; p = 0.034-p = 0.016). However, fractional anisotropy demonstrated a negative correlation with recovery of the Functional Ambulation Category (-0.359, p = 0.046). For the muscle imaging, significant inverse correlation was observed between vastus lateralis fat fraction vs. NIHSS recovery (-0.401, p = 0.04), and a strong positive correlation was observed between ratio of intra- to extra-myocellular lipid concentrations and the recovery of knee flexion (0.709, p = 0.007). This study supports previous literature indicating a positive correlation between the integrity of the corticospinal tract and motor recovery post-stroke, expanding the limited available literature describing this relationship specifically for the lower limb. However, recovery of functional ambulation behaved differently to other clinical recovery markers by demonstrating an inverse relationship with corticospinal tract integrity. The study also introduces some muscle imaging biomarkers as potentially valuable in the prediction of 3-month lower limb motor recovery following stroke.

Prediction of motor outcome based on brain perfusion single photon emission computed tomography in corona radiata infarct

BACKGROUND

There is limited information on brain perfusion single-photon emission computed tomography (SPECT) findings related to motor outcomes in patients with stroke. We aimed to investigate whether brain SPECT can be used to determine motor outcomes after corona radiata infarction.

METHODS

Eighty-nine patients were recruited in this study. Brain SPECT and diffusion tensor tractography (DTT) were conducted to evaluate the state of the corticospinal tract (CST) within 7-30 days of corona radiata infarct. Motor outcome was measured 6 months after infarct onset and was evaluated using the modified Brunnstrom classification (MBC) and functional ambulation category (FAC) for motor function of the upper and lower extremities, respectively. The presence of hypoperfusion on brain SPECT was evaluated in the frontal lobe, temporal lobe, parietal lobe, basal ganglia, thalamus, and cerebellum on both the ipsilesional and contralesional sides. Statistical analysis was performed using multivariate logistic regression, comparing patients in which CST was spared versus interrupted.

RESULTS

Hypoperfusion in the contralesional cerebellum was indicative of poor recovery in both the upper and lower extremities after corona radiata infarction when the CST was interrupted. Additionally, when the CST was preserved, hypoperfusion in the ipsilesional thalamus was indicative of poor recovery of the lower extremities.

CONCLUSION

Brain SPECT evaluation was shown to be a useful tool for predicting motor outcomes in patients with corona radiata infarcts.

Prediction of Motor Outcome of Stroke Patients Using a Deep Learning Algorithm with Brain MRI as Input Data

BACKGROUND

Deep learning techniques can outperform traditional machine learning techniques and learn from unstructured and perceptual data, such as images and languages. We evaluated whether a convolutional neural network (CNN) model using whole axial brain T2-weighted magnetic resonance (MR) images as input data can help predict motor outcomes of the upper and lower limbs at the chronic stage in stroke patients.

METHODS

We collected MR images taken at the early stage of stroke in 1,233 consecutive stroke patients. We categorized modified Brunnstrom classification (MBC) scores of ≥5 and functional ambulatory category (FAC) scores of ≥4 at 6 months after stroke as favorable outcomes in the upper and lower limbs, respectively, and MBC scores of <5 and FAC scores of <4 as poor outcomes. We applied a CNN to train the image data. Of the 1,233 patients, 70% (863 patients) were randomly selected for the training set and the remaining 30% (370 patients) were assigned to the validation set.

RESULTS

In the prediction of upper limb motor function on the validation dataset, the area under the curve (AUC) was 0.768, and for lower limb motor function, the AUC was 0.828.

CONCLUSION

We showed that a CNN model trained using whole-brain axial T2-weighted MR images of stroke patients would help predict upper and lower limb motor function at the chronic stage.

Practical Machine Learning Model to Predict the Recovery of Motor Function in Patients with Stroke

BACKGROUND

Machine learning (ML) is an artificial intelligence technique in which a system learns patterns and rules from a given data.

OBJECTIVES

The objective of the study was to investigate the potential of ML for predicting motor recovery in stroke patients.

METHODS

We analyzed data from 833 consecutive stroke patients using 3 ML algorithms: deep neural network (DNN), random forest, and logistic regression. We created a practical ML model using the most common data measured in almost all rehabilitation hospitals as input data. Demographic and clinical data, including modified Brunnstrom classification (MBC) and functional ambulation classification (FAC), were collected when patients were transferred to the rehabilitation unit (8-30 days) and 6 months after stroke onset and were used as input data. Motor outcomes at 6 months after stroke onset of the affected upper and lower extremities were classified according to MBC and FAC, respectively. Patients with an MBC of <5 and an FAC of <4 at 6 months after stroke onset were considered to have a "poor" outcome, whereas those with MBC ≥5 and FAC ≥4 were considered to have a "good" outcome.

RESULTS

The area under the curve (AUC) for the DNN model for predicting motor function was 0.836 for the upper and lower limb motor functions. For the random forest and logistic regression models, the AUCs were 0.736 and 0.790 for the upper and lower limb motor functions, respectively. The AUCs for the random forest and logistic regression models were 0.741 and 0.795 for the upper and lower limb motor functions, respectively.

CONCLUSION

Although we used simple and common data that can be obtained in clinical practice as variables, our DNN algorithm was useful for predicting motor recovery of the upper and lower extremities in stroke patients during the recovery phase.

Hematoma Evacuation via Image-Guided Para-Corticospinal Tract Approach in Patients with Spontaneous Intracerebral Hemorrhage

Introduction

Corticospinal tract injury caused by direct hematoma compression and secondary damage induced from blood toxic substances might influence the outcomes in patients with intracerebral hemorrhage (ICH). This study aimed to evaluate the safety and efficacy of hematoma evacuation via image-guided para-corticospinal tract approach based on the protection of compressed or residual corticospinal tract.

Methods

Seventy-five patients with ICH who underwent the image-guided para-corticospinal tract approach were retrospectively collected into the surgery group. Diffusion tensor imaging or computed tomography angiography was performed to identify the relationship between important white matter tracts and hematoma. The neuronavigation system for the preoperative imaging data loaded was used to identify the location of the burr hole, insertion trajectory, and depth of insertion. Cortical entry points and insertion trajectories were kept parallel to the corticospinal tract route into the hematoma based on the protection of compressed or residual corticospinal tract. Hematoma was removed under the image-guided para-corticospinal tract approach. Seventy-five age-, sex-, hematoma site-, and volume-matched patients with ICH who underwent conservative treatment were selected as controls. Demographical, clinical, radiological, and treatment-related data were retrospectively analyzed. Functional outcome was evaluated by modified Rankin scale on day 90.

Results

A total of 150 patients with ICH were retrospectively enrolled. The median Glasgow coma scale (GCS) score on admission was 11 (IQR 8–13). Deep hematoma (thalamus and basal ganglion) was present in 86.7% (130 patients). The mean hematoma volume on admission was 47 ± 19 mL, and the postoperative hematoma volume was 11 ± 10 mL. A higher proportion of favorable outcome was observed in the surgery group than in conservative treatment group (32.0% versus 17.4%; p = 0.037).

Conclusion

Hematoma evacuation via image-guided para-corticospinal tract approach based on the protection of compressed or residual corticospinal tract seems to be safer in patients with ICH with a relatively higher functional independence.

Does injury of the thalamocortical connection between the mediodorsal nucleus of the thalamus and the dorsolateral prefrontal cortex affect motor recovery after cerebral infarct?

We assessed the state of the thalamocortical connection between the mediodorsal nucleus (MD) and the dorsolateral prefrontal cortex (DLPFC) in patients with corona radiata infarct using diffusion tensor tractography (DTT). Altogether, 110 patients with corona radiata infarct were recruited, all of whom underwent DTT at an early stage following infarct onset. Based on the integrity of CST (CST+: CST was preserved around the infarct, CST-: CST was interrupted by the infarct) and the integrity of thalamocortical connection between the MD of thalamus and the DLPFC (DLPFC+: the connection was preserved, DLPFC-: the connection was interrupted), patients were divided into 4 groups: CST+/DLPFC+ (37 patients), CST+/DLPFC- (21 patients), CST-/DLPFC+ (25 patients), and CST-/DLPFC- (27 patients) groups. Motor function was evaluated using the upper Motricity Index (MI), lower MI, modified Brunnstrom classification, and the functional ambulation category at baseline and at 6 months post-onset. In patients with preserved CST integrity, the status of the thalamocortical connection had no impact on the assessed motor outcomes at 6 months post-stroke. However, in patients with disrupted CST integrity, those with preserved thalamocortical connection integrity had significantly higher motor function scores in all assessed outcomes 6 months post-stroke than those with disrupted thalamocortical connection integrity. The preservation or disruption of the thalamocortical connection between the MD of the thalamus and the DLPFC is an important factor for motor function recovery when CST integrity is also disrupted.

A systematic review of the usefulness of magnetic resonance imaging in predicting the gait ability of stroke patients

The usefulness of magnetic resonance imaging (MRI) in predicting gait ability in stroke patients remains unclear. Therefore, MRI evaluations have not yet been standardized in stroke rehabilitation. We performed a systematic review to consolidate evidence regarding the use of MRIs in predicting gait ability of stroke patients. The Medline, Cumulative Index to Nursing and Allied Health Literature, and SCOPUS databases were comprehensively searched. We included all literature published from each source’s earliest date to August 2020. We included 19 studies: 8 were classified as structure- or function-based MRI studies and 11 as neural tract integrity-based MRI studies. Most structure- or function-based MRI studies indicated that damage to motor-related areas (primary motor cortex, corona radiata, internal capsule, and basal ganglia) or insula was related to poor gait recovery. In neural tract integrity-based MRI studies, integrity of the corticospinal tract was related to gait ability. Some studies reported predictive value of the corticoreticular pathway. All included studies had some concerns, at least one, based on the Cochrane risk of bias instrument. This review suggests that MRIs are useful in predicting gait ability of stroke patients. However, we cannot make definitive conclusion regarding the predictive value, due to the lack of quantitative evaluations.

Prediction of Motor Function in Stroke Patients Using Machine Learning Algorithm: Development of Practical Models

BACKGROUND

Machine learning (ML) techniques are being increasingly adopted in the medical field.

OBJECTIVE

We developed a deep neural network (DNN) model and applied 2 well-known ML algorithms, logistic regression and random forest, in predicting motor outcome at 6 months after stroke.

METHODS

In the present study, by using 14 input variables which are easily measured by clinicians, we developed ML models and investigated their applicability to predicting motor outcome in hemiplegic stroke patients. We retrospectively analyzed data of 1,056 consecutive stroke patients. Favorable outcomes of the upper and lower limbs were defined as a modified Brunnstrom classification (MBC) score of ≥5 (able to perform activities of daily living with the affected upper limb) and a functional ambulation category (FAC) score of ≥4 (able to walk without guardian's assistance), respectively. Poor outcomes of the upper and lower limbs were defined as MBC and FAC scores of <5 and <4, respectively. We developed 3 ML algorithms, namely the DNN, logistic regression, and random forest.

RESULTS

Regarding the prediction of upper limb function, for the DNN model, the area under the curve (AUC) was 0.906. For the logistic regression and random forest models, the AUC were 0.874 and 0.882, respectively. For the prediction of lower limb function, for the DNN, logistic regression, and random forest models, the AUCs were 0.822, 0.768, and 0.802, respectively.

CONCLUSIONS

We demonstrated that the ML algorithms, particularly the DNN, can be useful for predicting motor outcomes in the upper and lower limbs at 6 months after stroke.

Prediction of ambulatory outcome in patients with corona radiata infarction using deep learning

Deep learning (DL) is an advanced machine learning approach used in diverse areas such as bioinformatics, image analysis, and natural language processing. Here, using brain magnetic resonance imaging (MRI) data obtained at early stages of infarcts, we attempted to develop a convolutional neural network (CNN) to predict the ambulatory outcome of corona radiata infarction at six months after onset. We retrospectively recruited 221 patients with corona radiata infarcts. A favorable outcome of ambulatory function was defined as a functional ambulation category (FAC) score of ≥ 4 (able to walk without a guardian's assistance), and a poor outcome of ambulatory function was defined as an FAC score of < 4. We used a CNN algorithm. Of the included subjects, 69.7% (n = 154) were assigned randomly to the training set and the remaining 30.3% (n = 67) were assigned to the validation set to measure the model performance. The area under the curve was 0.751 (95% CI 0.649-0.852) for the prediction of ambulatory function with the validation dataset using the CNN model. We demonstrated that a CNN model trained using brain MRIs captured at an early stage after corona radiata infarction could be helpful in predicting long-term ambulatory outcomes.

Essential Medical Information for Stroke Patients Undergoing Interhospital Transfer: A Delphi Study

OBJECTIVE

For improving the efficiency of transferring medical records for stroke patients undergoing interhospital transfer, we evaluated what is the essential medical information for physicians using the Delphi method.

DESIGN

We set up an expert panel of 31 physiatrists, who participated in this study. The 32 preliminary items of the transferred medical information were listed by a physiatrist for the first round of the Delphi method, and degree of necessity for these 32 items was evaluated using a 3-point scale ("very necessary," "necessary," and "not necessary"). We considered "very necessary" and "necessary" as "agreed to its necessity." According to the Delphi method, a satisfactory level of consensus can be achieved with the agreement of significant majority (≥80%) in the expert panel.

RESULTS

Based on the experts' feedback, some items were added as the preliminary items. After the second round of the Delphi method, the items confirmed to be necessary information during interhospital transfer were motor and sensory evoked potentials, Barthel Index, Mini-Mental State Examination/Global Deterioration Scale, Motor-Free Visual Perception Test, Manual Function Test, Purdue Pegboard Test, hand grip power, monofilament, 2-point discrimination test, Manual Muscle Test, Nottingham Scale, modified Brunnstrom Classification, functional ambulation category, Glasgow Coma Scale, language function test, imaging study, videofluoroscopic swallowing study, rehabilitation goal, previous medical history, comorbidity, and medication information.

CONCLUSIONS

If the previously mentioned necessary items are presented together at once during interhospital transfer, physicians who receive new stroke patients can evaluate patients' medical information more easily and completely.

Prediction of muscle loss after stroke by analysis of corticospinal tract

Introduction

Skeletal muscle loss induces a poor rehabilitation outcome after stroke. Little is known about the usefulness of diffusion tensor tractography (DTT) findings of the corticospinal tract (CST) in terms of predicting muscle loss in affected limbs after stroke.

Methods

This research was designed as a preliminary study. Forty-four patients, with stroke onset more than one year earlier, were recruited. DTT was performed within 7–30 days after stroke onset. The patients were classified into two groups based on the DTT findings: a DTT+ group, in which the CST was preserved, and a DTT− group, in which the CST was interrupted by the stroke lesion. Additionally, the patients’ functions were evaluated based on the modified Brunnstrom classification and functional ambulation category.

Results

In the DTT− group, the values of the lean tissue mass of the affected upper and lower limbs were smaller than those of the unaffected side. On the other hand, in the DTT+ group, the values of the lean tissue mass between the affected and unaffected limbs were not significantly different.

Conclusion

The DTT evaluation of CST at the early stage of stroke may be useful for predicting muscle loss of the affected limb at the chronic stage in stroke patients.

Diabetes does not affect motor recovery after intracerebral hemorrhage

Background

This retrospective study evaluated whether diabetes affects motor outcome after stroke by analyzing the effects of diabetes on motor prognosis by controlling for critical factors, including lesion type and location, corticospinal tract (CST) state, patient age, lesion volume, and treatment method during the stroke.

Methodology

We recruited 221 patients with intracerebral hemorrhage (ICH) of the basal ganglia. We used diffusion tensor tractography to investigate the CST state. We also evaluated the hemorrhage volume. We obtained information on the presence of diabetes and age by chart review. Motor outcomes at 6 months were measured using the upper and lower limb motricity index (MI), modified Brunnstrom classification (MBC), and functional ambulation category (FAC). We used multiple linear regression tests to investigate whether diabetes affected motor outcomes after stroke after adjusting for other factors, including CST state, age, lesion volume, and treatment method.

Results

The presence of diabetes was not correlated with motor outcome measurements, including upper and lower MIs, MBC, and FAC, at 6 months after the onset. However, the CST state, age, lesion volume, and treatment method were significantly correlated with nearly all motor outcomes.

Conclusions

We found that diabetes did not significantly affect motor outcomes after ICH.

Deterioration of Brain Neural Tracts in Elderly Women with Sarcopenia

OBJECTIVES

Sarcopenia is known to be associated with increased stiffness in brain arteries, which causes deterioration in brain structure and function. In this study, the authors evaluated the deterioration of neural tracts using diffusion tensor tractography (DTT) in elderly women with sarcopenia and investigated whether deterioration of neural tracts is consistent with clinical findings.

METHODS

Twenty elderly women with sarcopenia were recruited. Muscle mass was measured by dual energy x-ray absorptiometry. Hand-grip power and gait speed were also assessed. Memory function was evaluated using the Seoul Neuropsychological Screening Battery. Additionally, using DTT-Studio software, the authors evaluated eight neural tracts: the corticospinal tract (CST), corticoreticular pathway, fornix, cingulum, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and optic radiation. The authors measured the DTT parameters (fractional anisotropy [FA] and fiber volume [FV]) for each neural tract.

RESULTS

The FA and FV values were decreased in all the evaluated neural tracts, compared with those of the 20 normal comparison subjects. The FVs of the CST were significantly correlated with the hand-grip power of elderly women with sarcopenia. The FVs of the fornix and cingulum in elderly women with sarcopenia were significantly correlated with their memory function.

CONCLUSION

The authors found that the neural tracts in elderly women with sarcopenia were extensively deteriorated, and their hand-grip power and memory function were associated with related neural tracts. The DTT seems to be a useful tool for evaluating structural changes in the brains of people with sarcopenia.

Effects of Diabetes on Motor Recovery after Cerebral Infarct: A Diffusion Tensor Imaging Study

PURPOSE

Little is known about the effects of diabetes on motor recovery after cerebral infarct. To address this, we recruited patients with corona radiata infarct and controlled for the integrity of the corticospinal tract (CST) determined using diffusion tensor tractography (DTT).

METHODS

One hundred patients were recruited, and DTT was performed within 7-30 days of infarct onset. Based on the DTT findings (DTT+: CST was preserved around the infarct, DTT-: CST was interrupted by the infarct) and the presence (DM+) or absence (DM-) of diabetes, patients were divided into, DTT+/DM- (36 patients), DTT+/DM+ (19 patients), DTT-/DM- (32 patients), and DTT-/DM+ (13 patients) groups. Six months after cerebral infarct, motor function on the affected side was evaluated for each patient using the upper Motricity Index (MI), lower MI, modified Brunnstrom classification (MBC), and the functional ambulation category (FAC).

RESULTS

In the patients with a DTT+ finding, no motor function scores were significantly different between the DTT+/DM- and DTT+/DM+ groups at six-month evaluation. However, in patients with DTT- finding, all motor function scores at the six-month evaluation were significantly higher in the DTT-/DM- group than in the DTT-/DM+ group.

CONCLUSION

When the CST is interrupted by a corona radiata infarct, recovery of motor function in patients with diabetes is more impaired than those without diabetes.

Can the integrity of the corticospinal tract predict the long-term motor outcome in poststroke hemiplegic patients?

This study aimed to investigate the long-term motor outcome according to early diffusion tensor tractography findings for the affected corticospinal tract (CST) in poststroke hemiplegic patients. A total of 48 supratentorial subacute patients after stroke were enrolled, who had a brain MRI scan within 6 weeks from onset, and no stroke recurrence reported within the 2-year follow-up period. Diffusion tensor images were obtained and CSTs were reconstructed. The participants were classified into three groups: type A, the CST originating from the primary motor cortex was preserved around the lesion area; type B, the CST was similar to type A, except that the fiber originated from the area adjacent to the primary motor cortex; and type C, the CST was interrupted or not shown. Motor functions using Fugl-Meyer Motor Assessment (FMA), the Box and Block Test (BBT), and Functional Ambulation Category, and cognitive function using Mini-Mental Status Examination (MMSE) were measured at baseline and at 2 years from stroke onset. Changes in FMA and BBT were significantly different according to diffusion tensor tractography type at follow-up (P<0.05), but Functional Ambulation Category and Mini-Mental Status Examination were not. In post-hoc analysis, groups A and B showed greater significant improvements on the BBT and on the upper FMA subscale (shoulder/elbow, wrist, and hand) compared with group C (corrected P<0.05), but did not on lower FMA. This study showed the importance of CST integrity for stoke motor recovery. The early integrity of the CST may be useful in predicting long-term motor outcomes, specifically with motor recovery of the upper extremity and hand function.

The TWIST Algorithm Predicts Time to Walking Independently After Stroke

BACKGROUND AND OBJECTIVE

The likelihood of regaining independent walking after stroke is of concern to patients and their families and influences hospital discharge planning. The objective of this study was to explore factors that could be combined in an algorithm for predicting whether and when a patient will walk independently after stroke.

METHODS

Adults with new lower limb weakness were recruited within 3 days of having a stroke. Clinical assessment, transcranial magnetic stimulation, and magnetic resonance imaging were completed 1 to 2 weeks poststroke. Classification and regression tree (CART) analysis was used to identify factors that predicted whether a patient achieved independent walking by 6 or 12 weeks, or remained dependent at 12 weeks.

RESULTS

We recruited 41 patients (24 women; median age 72 years, range 43-96 years). The CART analysis results were used to create the Time to Walking Independently after STroke (TWIST) algorithm, which made accurate predictions for 95% of patients. Patients with a trunk control test score >40 at 1 week walked independently within 6 weeks. Patients with a trunk control test score <40 only achieved independent walking by 12 weeks if they also had hip extension strength of Medical Research Council grade 3 or more. Neurophysiological and neuroimaging measures did not predict independent walking after stroke.

CONCLUSIONS

In this exploratory study, the TWIST algorithm accurately predicted whether and when an individual patient walked independently after stroke using simple bedside measures 1 week poststroke. Further work is required to develop and validate this algorithm in a larger study.

Reduced foot pain after spasticity control with alcohol block in a patient with chronic hemiparetic stroke: a case report

[Purpose] This study report a case of a patient with hemiparetic stroke who showed significantly reduced foot pain when ankle spasticity was reduced using nerve and motor point blocks with 20% ethyl alcohol. [Subject and Methods] A 58-year-old woman with left hemiparesis following intracranial hemorrhage five years previously presented with pain in the left fifth metatarsal head for two years (numeric rating scale[NRS]: 8). Erythema and edema were observed on the lateral aspect of the head of the fifth metatarsal bone. She was diagnosed with a Tailor's bunion. Spasticity was observed in the left ankle plantar flexor and ankle supinator (Modified Ashworth Scale: 1+). Using 20% ethyl alcohol, a block in the medial and lateral motor branches to the gastrocnemius muscle of the left tibial nerve and the motor point of the left posterior tibialis muscle was performed. [Results] After the alcohol block, spasticity had almost disappeared and foot pain was significantly reduced (NRS: 1). Results from the foot pressure measurement system test showed foot contact pressure was highly distributed to the lateral forefoot pre-block. After the block, the distribution of foot contract pressure was similar to normal distribution. [Conclusion] Clinicians should consider the possibility that spasticity can contribute to foot pain.

Correlation between ambulatory function and clinical factors in hemiplegic patients with intact single lateral corticospinal tract: A pilot study

To define the relationship between the complete destruction of 1 lateral corticospinal tract (CST), as demonstrated by diffusion tensor imaging (DTI) tractography, and ambulatory function 6 months following stroke.Twenty-six adults (17 male, 9 female) with poststroke hemiplegia who were transferred to the physical medicine and rehabilitation department. Participants underwent DTI tractography, which showed that 1 lateral CST had been clearly destroyed.Functional ambulation classification (FAC) scores at admission, discharge, and 6 months after discharge were used to evaluate the patients' ability to walk. The National Institutes of Health Stroke Scale (NIHSS) and the Korean version of the modified Barthel index (K-MBI) at admission, discharge, and 6 months after discharge were used to evaluate the degree of functional recovery.Of the 26 patients, 18 were nonambulatory (FAC level 1-3), and 8 were able to walk without support (FAC level 4-6). The type of stroke (infarction or hemorrhage), site of the lesion, spasticity of lower extremities, cranioplasty, and the time taken from onset to MRI were not statistically significantly correlated with the ability to walk. However, statistically significant correlations were found in relation to age, K-MBI scores, and initial NIHSS scores.Despite the complete damage to the lesion site and the preservation of 1 unilateral CST, as shown by DTI, good outcomes can be predicted on the basis of younger age, low NIHSS scores, and high MBI scores at onset.

Transcranial Magnetic Stimulation and Diffusion Tensor Tractography for Evaluating Ambulation after Stroke

BACKGROUND AND PURPOSE

We aimed to investigate the usefulness of combining transcranial magnetic stimulation (TMS) and diffusion tensor tractography (DTT) to evaluate corticospinal tract (CST) integrity and subsequently predict ambulatory function after middle cerebral artery (MCA) stroke.

METHODS

Forty-three patients with first MCA stroke underwent TMS and DTT to evaluate CST integrity. Patients were classified into four groups according to the presence of motor-evoked potentials (MEPs) obtained from the tibialis anterior muscle and CST integrity. Motor impairment and functional status were assessed using the Fugl-Meyer Assessment, Functional Ambulation Category, and Korean modified Barthel Index, both at the time of admission and after 4 weeks of rehabilitation.

RESULTS

Patients with the presence of both measurable MEPs and a preserved CST showed better motor recovery and ambulatory function than other groups at the 4-week follow-up. Intact CSTs were not visualized in patients without detectable MEPs. Among the patients displaying MEPs, those with preserved CSTs showed better recovery of paretic lower extremities.

CONCLUSIONS

Combined assessment using TMS and DTT to evaluate CST integrity confers advantages in predicting motor and ambulation recovery in patients with MCA stroke.

Motor outcomes of patients with a complete middle cerebral artery territory infarct

Detailed knowledge of motor outcomes enables to establish proper goals and rehabilitation strategies for stroke patients. Several previous studies have reported functional or motor outcomes in patients with a middle cerebral artery territory infarct. However, little is known about motor outcome in patients with a complete middle cerebral artery territory infarct. In this study, we investigated the motor outcomes in 23 patients with a complete middle cerebral artery territory infarct. All of these patients received comprehensive rehabilitative management, including movement therapy and neuromuscular electrical stimulation of the affected finger extensors and ankle dorsiflexors, for more than 3 months. Motor outcomes were measured at 6 months after stroke onset using the Medical Research Council, Motricity Index, the modified Brunnstrom Classification, and Functional Ambulation Category scores. The motor function of the lower extremities was found to be better than that of the upper extremities. After receiving rehabilitation treatments for 3-6 months, about 70% of these patients were able to walk independently (Functional Ambulation Category scores > 3), but no patient achieved functional hand recovery.