A structural analysis of the rail unit of an indoor assistive mobility system.

BACKGROUND: Individuals with gait disturbances, such as that post-stroke, are discharged home to undergo outpatient rehabilitation. Rehabilitation in the community is not as effective as that in hospital, due to long travel times and short program duration. OBJECTIVE: This study analyzed rail unit structure, with the aim of assisting home indoor assistive mobility system (HIAMS) development, allowing patients to undergo gait-related rehabilitation training at home. METHODS: The HIAMS consists of a mobile rail running around the whole room, a turn-table for movement between rails, and a weight-supporting component. Structural analysis was performed using the Abaqus/CAE solution (Version 6.14, Dassault systems, Inc.) to verify device safety, according to the load applied to the rail and turn-table units. The load was applied vertically at 150 kg to reflect the weight of potential users. RESULTS: Structural analysis was performed on the weight-supporting components, which was consist of turn-table case, bearing components (center, left), connective bracket and rail rollers. The safety factors of each components were estimated as 1.31, 5.39 (bearing, center), 8.45 (bearing, left), 1.43 and 3.61 in sequence. CONCLUSION: We demonstrated a safety factor of ⩾ 1.3 for the key system units, suggesting this technology is safe for use in the home rehabilitation training of individuals with gait impairment post-ICU stay.

Injury of the Spinothalamic Tract Following Whiplash Injury: A Diffusion Tensor Tractography Study.

OBJECTIVES: Using diffusion tensor tractography (DTT), we demonstrated the spinothalamic tract (STT) injury in patients with central pain following whiplash injury. Our primary hypothesis is that fractional anisotropy (FA) and tract volume (TV) of the STT in injured people differ from non-injured people. Our secondary hypothesis is that the direction of the collision results in a different type of injury. METHODS: Nineteen central pain patients following whiplash injury and 19 normal control subjects were recruited. The STT was reconstructed by the DTT, the FA and TV of the STT were measured. In addition, different characteristics of the STT injury according to the collision direction were investigated. RESULTS: The FA value did not differ significantly between the patient and control groups (p > 0.05). However, the significantly lower value of the TV was observed in patient group than the control group (p < 0.05). The onset of central pain was significantly delayed (13.5 days) in patients who were involved in a frontal collision, compared to patients with rear-end collision (0.6 days) (p < 0.05). In contrast, the Visual Analogue Scale was higher in the patients with rear-end collision (p < 0.05). CONCLUSIONS: We found the STT injury mild traumatic brain injury (TBI) who suffered central pain after whiplash injury, using DTT. In addition, we demonstrated different characteristics of the STT injury according to the collision direction. We believe that injury of the STT would be usefully detected by DTT following whiplash injury.

Diffusion tensor tractography characteristics of axonal injury in concussion/mild traumatic brain injury.

The main advantage of diffusion tensor tractography is that it allows the entire neural tract to be evaluated. In addition, configurational analysis of reconstructed neural tracts can indicate abnormalities such as tearing, narrowing, or discontinuations, which have been used to identify axonal injury of neural tracts in concussion patients. This review focuses on the characteristic features of axonal injury in concussion or mild traumatic brain injury (mTBI) patients through the use of diffusion tensor tractography. Axonal injury in concussion (mTBI) patients is characterized by their occurrence in long neural tracts and multiple injuries, and these characteristics are common in patients with diffuse axonal injury and in concussion (mTBI) patients with axonal injury. However, the discontinuation of the corticospinal tract is mostly observed in diffuse axonal injury, and partial tearing and narrowing in the subcortical white matter are frequently observed in concussion (mTBI) patients with axonal injury. This difference appears to be attributed to the observation that axonal injury in concussion (mTBI) patients is the result of weaker forces than those producing diffuse axonal injuries. In addition, regarding the fornix, in diffuse axonal injury, discontinuation of the fornical crus has been frequently reported, but in concussion (mTBI) patients, many collateral branches form in the fornix in addition to these findings in many case studies. It is presumed that the impact on the brain in TBI is relatively weaker than that in diffuse axonal injury, and that the formation of collateral branches occurs during the fornix recovery process. Although the occurrence of axonal injury in multiple areas of the brain is an important feature of diffuse axonal injury, case studies in concussion (mTBI) have shown that axonal injury occurs in multiple neural tracts. Because axonal injury lesions in mTBI patients may persist for approximately 10 years after injury onset, the characteristics of axonal injury in concussion (mTBI) patients, which are reviewed and categorized in this review, are expected to serve as useful supplementary information in the diagnosis of axonal injury in concussion (mTBI) patients.

Neurogenic fever due to injury of the hypothalamus in a stroke patient: Case report.

RATIONALE: Neurogenic fever is a non-infectious source of fever in a patient with brain injury, especially hypothalamic injury. We report on a stroke patient with neurogenic fever due to injury of hypothalamus, demonstrated by using diffusion tensor imaging (DTI). PATIENT CONCERNS: A 28-year-old male patient was admitted to the rehabilitation department of university hospital at 30 months after onset. Brain MRI showed leukomalactic lesions in hypothalamus, bilateral medial temporal lobe, and bilateral basal ganglia. He showed intermittent high body temperature (maximum:39.5°C, range:38.5-39.2°C), but did not show any infection signs upon physical examination or after assessing his white blood cell count and inflammatory enzyme levels such as erythrocyte sedimentation rate and C-reactive protein. In addition, 8 age-matched normal (control) subjects (4 male, mean age: 26.6 years, range: 21-29years) were enrolled in the study. DIAGNOSIS: Intraventricular hemorrhage and intracerebral hemorrhage in the left basal ganglia. INTERVENTIONS: He underwent extraventricular drainage and ventriculoperitoneal shunting for hydrocephalus. OUTCOMES: DTI was performed at 30 months after onset, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained for hypothalamus. The FA and ADC values of patient were lower and higher, respectively, by more than two standard deviations from control values. Injury of hypothalamus was demonstrated in a stroke patient with neurogenic fever. LESSIONS: Our results suggest that evaluation of hypothalamus using DTI would be helpful in patients show unexplained fever following brain injury.

Title: Injury characteristics of the Papez circuit in patients with diffuse axonal injury: a diffusion tensor tractography study.

We investigate the characteristics of injury of four portions of the Papez circuit in patients with diffuse axonal injury (DAI), using diffusion tensor tractography (DTT). Thirty-four consecutive patients with DAI and 30 normal control subjects were recruited. Four portions of the Papez circuit were reconstructed: the fornix, cingulum, thalamocingulate tract, and mammillothalamic tract. Analysis of DTT parameters [fractional anisotropy (FA) and tract volume (TV)] and configuration (narrowing, discontinuation, or non-reconstruction) was performed for each portion of the Papez circuit. The Memory Assessment Scale (MAS) was used for the estimation of cognitive function. In the group analysis, decreased fractional anisotropy and tract volume of the entire Papez circuit were observed in the patient group compared with the control group (p < 0.05). In the individual analysis, all four portions of the Papez circuit were injured in terms of DTT parameters or configuration. Positive correlation was observed between TV of the fornix and short-term memory on MAS r = 0.618, p < 0.05), and between FA of the fornix and total memory on MAS (r = 0.613, p < 0.05). We found that all four portions of the Papez circuit in the patient group were vulnerable to DAI, and among four portions of the Papez circuit, the fornix was the most vulnerable portion in terms of injury incidence and severity.

Complete monoplegia due to limb-kinetic apraxia in a patient with traumatic brain injury: A case report.

RATIONALE: Limb-kinetic apraxia (LKA) is a disorder of movement execution that is a result of injury to the corticofugal tracts (CFTs) from the secondary motor area. We report on a patient with traumatic brain injury (TBI) and complete monoplegia due to LKA, which was mainly ascribed to injury of the CFT from the secondary motor area using diffusion tensor tractography. PATIENT CONCERNS: A 35-year-old male was struck by a car from the side during riding an autocycle and received direct head trauma as a result of falling to ground. He lost consciousness for approximately 1 month and experienced continuous post-traumatic amnesia after the accident. The patient's Glasgow Coma Scale score was 3 and he showed quadriparesis including complete monoplegia of his left arm since the onset of TBI. DIAGNOSES: The patient diagnosed complete monoplegia due to LKA after traumatic brain injury. INTERVENTIONS: He underwent conservative management for TBI followed by rehabilitation at approximately 2 months after onset. OUTCOMES: At 32-month after onset, weakness on left arm (Manual Muscle Test [MMT]:0) and partial weakness of left leg (MMT:3). OUTCOMES: Results of electromyography and nerve conduction studies of left extremities were normal. Motor evoked potential values obtained from the abductor pollicis brevis muscle (APB) were: right APB latency 22.3msec, amplitude 1.6mV; left APB latency 22.8msec, amplitude 1.5mV. After 2 weeks of administration of dopaminergic drugs for improvement of LKA, left arm weakness had recovered to level that permitted movement against gravity (MMT:3). Diffusion tensor tractography at 32-month after onset showed right corticospinal tract discontinuation at the pontine level and partial tearing of the left corticospinal tract at the subcortical white matter. In addition, the left CFT from the supplementary motor area showed partial tearing at the subcortical white matter. LESSONS: The LKA due to injury of the left supplementary motor area-CFT was demonstrated in a patient with complete monoplegia following TBI. Accurate diagnosis of LKA is important for successful rehabilitation because LKA is known to respond to dopaminergic drug treatment.

Injury of the optic radiation in patients with mild TBI: A DTT study.

OBJECTIVES: We investigated injuries of the optic radiations (ORs) in patients with mild traumatic brain injury (TBI) by using diffusion tensor tractography (DTT). METHODS: Fifty-two consecutive patients who complained of visual problems showed abnormal visual evoked potential (VEP) latency but no abnormality on conventional brain MRI after mild TBI, and fifty normal control subjects were recruited for this study. Subjects' ORs were reconstructed using DTT, and three DTT parameters (fractional anisotropy [FA], apparent diffusion coefficient [ADC], and tract volume) were measured for each OR. RESULTS: Mean FA value and tract volume of the OR were significantly lower in the patient group than in the control group (p < 0.05). However, there was no significant difference in the ADC values of the OR between the patient and control groups (p > 0.05). A weak negative correlation was detected between VEP latency and OR fiber number (r = 0.204, p < 0.05). CONCLUSIONS: DTT revealed that OR injuries were not detected on the conventional brain MRI scans of patients who complained of visual problems and had abnormal VEP latency after mild TBI. Our results suggest that DTT would be a useful technique for detecting OR injury in patients with mild TBI.

Recovery of Injured Optic Radiations in a Patient with Hypoxic-Ischaemic Brain Injury.

The introduction of diffusion tensor tractography (DTT) has made three-dimensional reconstruction of the optic radiation (OR) possible in the human brain. A 19-year-old female patient underwent conservative management for hypoxic-ischaemic brain injury. Four months after onset she was transferred to the rehabilitation department of our university hospital. The patient was in a vegetative state with a coma recovery scale-revised (CRS-R) score of nine. She underwent comprehensive rehabilitation, which included medications, physical therapy, and occupational therapy. Transcranial direct current stimulation was applied to the upper occipital area. After one month of rehabilitation, she had recovered to a minimally conscious state with a CRS-R score of 15. Some recovery of the injured ORs was demonstrated by DTT.

Motor recovery by the aberrant pyramidal pathway in a patient with cerebral infarct.

INTRODUCTION: The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract (PT) descending through the medial lemniscus in the midbrain and pons. We report on a patient who showed changes of the APT from the early stage to the chronic stage concurrent with motor recovery following an infarct in the cerebral peduncle. PATIENT CONCERNS: An 84-year-old female patient presented with moderate motor weakness of her upper and lower extremities (2/2) due to cerebral infarct on the right cerebral peduncle of midbrain. One week after her stroke, her motor weakness was similar to that at the onset (2/2). During 5 weeks' rehabilitation, her motor weakness recovered to the point that she was able to move upper and lower extremities against gravity with some resistance (4/4). DIAGNOSIS: Cerebral infarct on the right cerebral peduncle of midbrain INTERVENTIONS:: She participated in a comprehensive rehabilitative management program, including movement therapy, neurotrophic drugs, and neuromuscular electrical stimulation therapy of the left finger extensor and ankle dorsiflexor muscles. OUTCOMES: On 1-week and 6-week diffusion tensor tractographys (DTTs), the right PT was not reconstructed, but the right APT, which descended through the medial lemniscus pathway at the midbrain and pons and the pyramid at the medulla, was observed. The right APT became thicker on six-week DTT compared with 1-week DTT. On 1-week transcranial magnetic stimulation study, an motor evoked potential with delayed latency and decreased amplitude was evoked from the affected (right) hemisphere (latency: 24.4 msec and amplitude: 0.2uV). In contrast, its latency was decreased and amplitude was increased on six-week transcranial magnetic stimulation study (latency: 21.8 msec, amplitude: 0.8 uV) CONCLUSIONS:: We demonstrated changes in the APT from the early stage to the chronic stage concurrent with motor recovery in a patient with an infarct in the cerebral peduncle. Our findings have important implications that a spared APT could contribute to the motor recovery in patients with cerebral infarct when the PTis completely injured at the onset of cerebral infarct,.

Increased thalamocortical connectivity to the medial prefrontal cortex with recovery of impaired consciousness in a stroke patient: A case report.

RATIONALE: We report a stroke patient who showed increased thalamocortical connectivity to the medial prefrontal cortex (mPFC) with recovery of impaired consciousness that was demonstrated on diffusion tensor tractography (DTT) of the ascending reticular activating system (ARAS). PATIENTS CONCERNS: A 48-year-old male patient underwent craniectomy and hematoma removal for spontaneous intracerebral hemorrhage in the right basal ganglia and thalamus. When he started rehabilitation at 5 weeks after onset he was in a vegetative state with a Coma Recovery Scale-Revised score of 6. DIAGNOSES: The patient was diagnosed spontaneous intracerebral hemorrhage in the right basal ganglia and thalamus. INTERVENTIONS: He underwent comprehensive rehabilitation including neurotropic durgs, transcranial direct current stimulation, and repetitive transcranial magnetic stimulation of the left prefrontal lobe (Brodmann area 10). OUTCOMES: After 5 weeks of rehabilitation, the patient had recovered to a nearly normal conscious state with a Coma Recovery Scale-Revised score of 22. On 10-week DTT, thickening of the lower dorsal ARAS was observed on both sides compared with 5-week DTT. Decreased neural connectivity to the left PFC was observed on 5-week DTT whereas decreased neural connectivity to the left PFC was increased on 10-week DTT, especially the mPFC. LESSONS: Increased thalamocortical connectivity to the mPFC was demonstrated in a stroke patient who showed concomitant recovery from a vegetative state to a nearly normal conscious state. The results suggest that the increased neural connectivity to the mPMC contributed to recovery of consciousness in this patient.

Diagnosis of Complex Regional Pain Syndrome I Following Traumatic Axonal Injury of the Corticospinal Tract in a Patient with Mild Traumatic Brain Injury.

A 54-year-old male suffered from direct head trauma resulting from a fall while working. At approximately two months after the accident, he began to feel pain (burning sensation) and swelling of the dorsum of the right hand and wrist. He showed the following clinical features among the clinical signs and symptoms of revised diagnostic criteria for complex regional pain syndrome (CRPS): spontaneous pain, mechanical hyperalgesia, vasodilation, skin temperature asymmetries, skin color changes, swelling, motor weakness. No specific lesion was observed on brain MRI taken at ten weeks after onset. Plain X-ray, electromyography, and nerve conduction studies for the right upper extremity detected no abnormality. A three-phase bone scan showed hot uptake in the right wrist in the delayed image. On two-month diffusion tensor tractography, partial tearing of the corticospinal tract (CST) was observed at the subcortical white matter in both hemispheres (much more severe in the left CST). In addition, the fiber number of the right CST was significantly decreased than that of seven normal control subjects. CRPS I of the right hand in this patient appeared to be related to traumatic axonal injury of the left CST following mild traumatic brain injury.

Difference between injuries of the corticospinal tract and corticoreticulospinal tract in patients with diffuse axonal injury: a diffusion tensor tractography study.

Objectives: No studies have investigated differences in injury of the corticospinal tract (CST) and corticoreticulospinal tract (CRT) following diffuse axonal injury (DAI) to date. Therefore, we investigated differences in injury of the CST and CRT in patients with DAI using diffusion tensor tractography (DTT).Methods: Twenty consecutive patients with DAI and 20 control subjects were recruited. CST and CRT were reconstructed. Each part of the CST and CRT was analyzed in terms of DTT parameters and configuration.Results: Upon group analysis, decreased FA and TV values were observed in both the CST and CRT in the patient group compared with the control group (%) (p < .05). In the individual analysis in terms of the TV, significantly higher injury incidence was observed for the CRT (47.5%) than the CST (25.0%) (p < .05). Evaluation of the DTT configuration revealed significantly higher injury incidence for the CRT (50.0%) than the CST (17.5%) (p < .05). Specifically, the incidence of discontinuation was significantly higher for the CRT (40.0%) than the CST (10.0%) (p < .05).Conclusions: Injury of the CST and CRT was detected in patients with DAI using DTT. In terms of the incidence and severity of neural injury, the CRT appeared to be more vulnerable to DAI than the CST.

Diagnosis of Conversion Disorder Using Diffusion Tensor Tractography and Transcranial Magnetic Stimulation in a Patient with Mild Traumatic Brain Injury.

We report on a patient with mild traumatic brain injury (TBI) who was diagnosed with conversion disorder for severe weakness of an arm, which was demonstrated using diffusion tensor tractography (DTT) and transcranial magnetic stimulation (TMS). A 23-year-old right-handed female suffered from head trauma resulting from a pedestrian car accident. She underwent rehabilitative management for memory impairment and central pain. At 14 months after onset, she complained of severe weakness of her right arm, which was detected in the morning after sleeping (right shoulder abductor: 3/5, elbow flexor: 3/5, wrist extensor: 1/5, finger flexor: 1/5, and finger extensor: 1/5). Electromyography study for peripheral neuropathy performed at 2 weeks after onset of weakness showed no abnormality. On a 14-month DTT configuration, the integrities of the left corticospinal tract (CST), supplementary motor area-corticofugal tract (SMA-CFT), and dorsal premotor cortex (dPMC)-CFT were well-preserved. Significant differences were not observed for the fractional anisotropy (FA), mean diffusivity (MD), and tract volume (TV) values of the CST, SMA-CFT, and dPMC-CFT in both hemispheres between the patient and ten right-handed age- and sex-matched normal subjects (p > 0.05). On a 14-month TMS study, MEPs obtained at the right abductor pollicis brevis muscle showed no abnormality. Using DTT and TMS, conversion disorder was demonstrated in a patient with mild TBI, who showed severe weakness of an arm. Our results suggest the usefulness of an evaluation of the CST and CFTs from the secondary motor areas using DTT, and the CST using TMS for patients who complain of motor weakness due to conversion disorder.

Headache due to spinothalamic tract injury in patients with mild traumatic brain injury: Two case reports.

RATIONALE: Headache is the most common physical complaint reported by the following traumatic brain injury (TBI). Several studies using diffusion tensor tractography (DTT) have demonstrated that injury of the spinothalamic tract (STT) is a pathogenetic mechanism of central pain following TBI. However, no study of headache due to injury of the STT has been reported. PATIENT CONCERNS: Patient 1 was a 52-year-old female who suffered head trauma resulting from an in-car traffic crash. While sitting in a passenger seat in a moving vehicle, another vehicle suddenly hit the car from the right side. Her head hit the door and she suffered a flexion-hyperextension-rotation injury. She began to feel headaches in both fronto-parieto-occipital areas approximately 2 weeks after the crash. The characteristics and severity of pain were as follows: constant tingling and intermittent stabbing pain without allodynia or hyperalgesia (visual analogue scale score: 7). Patient 2 was a 50-year-old male who suffered head trauma from a flexion-hyperextension injury that occurred after being hit from behind by a vehicle while driving his car. He began to feel headache in both fronto-parieto-occipital areas the day after the crash: constant tingling pain without allodynia or hyperalgesia (visual analogue scale score: 6). DIAGNOSES: The patient 1 was diagnosed as mild TBI due to head flexion-hyperextension-rotation injury. The patient 2 was diagnosed as mild TBI due to head flexion-hyperextension injury. INTERVENTIONS: Clinical assessment and DTT were performed at 5 months (patient 1) and 10 months (patient 2) after the initial injury. OUTCOMES: On DTTs of patient 1 and 2, the STTs showed narrowing in both hemispheres. In addition, discontinuations at the subcortical white matter were observed in both hemispheres in patient 2. LESSONS: Headache due to injury of the STT was diagnosed in patients with mild TBI. Precise diagnosis of central pain from other types of pain is clinically important because the management of central pain is quite different from those for other types of pain. Our results suggest that headache might be ascribed to the injury of the STT in patients with mild TBI. Therefore, we recommend evaluation of the STT using DTT in patients with mild TBI who complain of headache having the characteristics of neuropathic pain.

Recovery of an injured corticospinal tract via an unusual pathway in a stroke patient: Case report.

RATIONALE: A few mechanisms of recovery from an injured corticospinal tract (CST) in stroke patients have been reported: recovery of an injured CST through (1) normal CST pathway, (2) peri-lesional reorganization, and (3) shifting of the cortical origin area of an injured CST from the other areas to the primary motor cortex. However, it has not been clearly elucidated so far. PATIENT CONCERNS: A 57-year-old male patient presented with complete weakness of the right extremities due to an intracerebral hemorrhage (ICH) in the left basal ganglia. At three weeks after onset, the patient showed severe weakness of his right upper and lower extremities (Motricity Index [MI]: 28/100, finger extensor: 0/5). At 6 months after onset, his weakness showed some recovery, however, right finger extensor did not show any recovery (MI: 51/100, finger extensor: 0/5). At 9 months after onset, weakness showed significant recovery, particularly right finger extensor (MI: 64/100, right finger extensor: 3/5) and similar motor function persisted until 11 months after onset (MI: 67/100, right finger extensor: 3/5). DIAGNOSES: The patient was diagnosed as the right hemiplegia due to ICH in the left corona radiata and basal ganglia. INTERVENTIONS: Clinical assessment, transcranial magnetic stimulation (TMS), and diffusion tensor tractography (DTT) were performed at 1, 6, 9, and 11 months after onset. OUTCOMES: Discontinuation of the left CST at the midbrain level was observed on 1-month DTT and the corona radiata on 6-month DTT. However, on 9-month DTT, we observed a CST branch originating from the left posterior parietal cortex and then connecting to the main truck to the CST at the thalamic level and thickened on 11-month DTT. On 1-month TMS, no MEP was evoked from the left hemisphere; on 6-month TMS study, MEPs were obtained at a right hand muscle (latency: 22.8 ms, amplitude: 130 µV) and its amplitude was increased as 300 µV with similar latencies on 9- and 11-month TMS studies. LESSONS: Recovery of an injured CST via an unusual pathway was demonstrated in a hemiparetic patient with ICH, using DTT and TMS. We believe that our results suggest that precise evaluation for an injured CST using TMS and DTT might be necessary, particularly in young patients, even after 6 months from onset even though the stroke patients show clinical characteristics of severe injury of the affected CST.