Gait training with a wearable powered robot during stroke rehabilitation: a randomized parallel-group trial.

BACKGROUND: We have developed a wearable rehabilitation robot, "curara®," and examined its immediate effect in patients with spinocerebellar degeneration and stroke, but its rehabilitative effect has not been clarified. The purpose of this study was to examine the effect of this device on gait training in stroke patients. METHODS: Forty stroke patients were enrolled in this study. The participants were divided randomly into two groups (groups A and B). The participants assigned to group A received RAGT with curara® type 4, whereas those in group B received conventional therapist-assisted gait training. The clinical trial period was 15 days. The participants performed 10 sessions of gait training (5 times per week) each lasting 30 ± 5 min per day. The 10-m walking time (10mWT), and 6-minute walking distance (6MWD) were evaluated as the main outcomes. Timed up and go and Berg Balance Scale (BBS) were also examined. Gait parameters (stride duration and length, standard deviation of stride duration and length, cadence, ratio of the stance/swing phases, minimum/maximum knee joint angle, and minimum/maximum hip joint angle) were measured using a RehaGait®. The items other than BBS were measured on days 0, 7, and 14, whereas BBS was measured on days 0 and 14. The improvement rate was calculated as the difference of values between days 14 and 0 divided by the value on day 0. The improvement rates of the 10mWT and 6MWD were set as the main outcomes. RESULTS: The data of 35 participants were analyzed. There was no significant difference in the main outcomes between both groups at the end of gait training. As for intragroup changes, gait speed, stride length, stride duration, and cadence were improved significantly between days 0 and 14 in each group. When examining the interaction effect between the day of measurement and group, stride duration (p = 0.006) and cadence (p = 0.012) were more significantly improved in group A than in group B. CONCLUSIONS: This novel wearable powered robot may have the potential to improve gait speed of individuals in stroke rehabilitation. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCTs032180163). Registered on February 22, 2019; https://jrct.niph.go.jp/en-latest-detail/jRCTs032180163 . UMIN CLINICAL TRIALS REGISTRY (UMIN000034237): Registered on September 22, 2018; https://center6.umin.ac.jp/cgi-open-bin/icdr/ctr_view.cgi?recptno=R000038939 .

Gait training with a wearable curara® robot for cerebellar ataxia: a single-arm study.

BACKGROUND: Ataxic gait is one of the most common and disabling symptoms in people with degenerative cerebellar ataxia. Intensive and well-coordinated inpatient rehabilitation improves ataxic gait. In addition to therapist-assisted gait training, robot-assisted gait training has been used for several neurological disorders; however, only a small number of trials have been conducted for degenerative cerebellar ataxia. We aimed to validate the rehabilitative effects of a wearable "curara®" robot developed in a single-arm study of people with degenerative cerebellar ataxia. METHODS: Twenty participants with spinocerebellar ataxia or multiple system atrophy with predominant cerebellar ataxia were enrolled. The clinical trial duration was 15 days. We used a curara® type 4 wearable robot for gait training. We measured the following items at days 0, 7, and 14: Scale for the Assessment and Rating of Ataxia, 10-m walking time (10 mWT), 6-min walking distance (6 mWD), and timed up and go test. Gait parameters (i.e., stride duration and length, standard deviation of stride duration and length, cadence, ratio of the stance and swing phases, minimum and maximum knee joint angles, and minimum and maximum hip joint angles) were obtained using a RehaGait®. On days 1-6 and 8-13, the participants were instructed to conduct gait training for 30 ± 5 min with curara®. We calculated the improvement rate as the difference of values between days 14 and 0 divided by the value on day 0. Differences in the gait parameters were analyzed using a generalized linear mixed model with Bonferroni's correction. RESULTS: Data from 18 participants were analyzed. The mean improvement rate of the 10 mWT and 6 mWD was 19.0% and 29.0%, respectively. All gait parameters, except the standard deviation of stride duration and length, improved on day 14. CONCLUSIONS: Two-week RAGT with curara® has rehabilitative effects on gait function comparable to those of therapist-assisted training. Although the long-term effects after a month of RAGT with curara® are unclear, curara® is an effective tool for gait training of people with degenerative ataxia. Trial registration jRCT, jRCTs032180164. Registered: 27 February 2019; retrospectively registered. https://jrct.niph.go.jp/en-latest-detail/jRCTs032180164 .

Effects of gait support in patients with spinocerebellar degeneration by a wearable robot based on synchronization control.

BACKGROUND: Spinocerebellar degeneration (SCD) mainly manifests a cerebellar ataxic gait, leading to marked postural sway and the risk of falling down. Gait support using a wearable robot is expected to be an effective solution to maintaining the status quo and/or delaying symptom progression. The aim of this study was to evaluate the effects of gait support in patients with SCD by using a wearable robotic system called curara ®; while undergoing walking tests. METHODS: The curara system assists both the hip and knee joints and supports the wearer's rhythmic gait using a synchronization control based on a central pattern generator. The system reflects the wearer's intended motion in response to the gait support by detecting an interactive force that is generated from slight movements of the wearer. The degree of coordinated motion between the robot and the wearer can be adjusted by modifying the synchronization gain. In this study, we provided gait support using three high-gain conditions (A, B, C) to more easily follow the wearer's movement in each joint. The synchronization gains for both the hip and knee joints (i.e., Ch and Ck) were set at 0.5 for condition A and at 0.4 for condition B. Condition C had different gains for the hip and knee joints (i.e., Ch=0.4 and Ck=0.5). With the walking test, we assessed the effects of the gait support provided by the curara system on walking smoothness (measured using the harmonic ratio: HR) and spatiotemporal parameters (gait speed, stride length, cadence) in SCD patients (n=12). We compared the performance between the three high-gain conditions and without assistance from the robot. RESULTS: Under condition C, the HRs in the anteroposterior, mediolateral, and vertical directions (HR-AP, HR-ML, and HR-V) were especially high compared with those under conditions A and B. The results of the statistical analyses using repeated measures analysis of variance followed by Tukey's test showed that gait support with condition C results in a statistically significant increase in the HR-AP (2.04 ±0.52; p=0.025) and HR-V (2.06 ±0.37; p=0.032) when compared with walking without assistance from the system. In contrast, the gait speed, stride length, and cadence under condition C were no major changes in most patients, compared with the patient's walking without assistance. CONCLUSIONS: The significantly increased HR indicates that gait support under condition C achieved smoother walking than when not wearing the power unit of the system. Consequently, we suggest that gait support using the curara system has the potential to improve walking smoothness in patients with SCD.

Inter-generational instability of inserted repeats during transmission in spinocerebellar ataxia type 31.

The causative mutation for spinocerebellar ataxia type 31 (SCA31) is an intronic insertion containing pathogenic pentanucleotide repeats, (TGGAA)n. We examined to what degree the inserted repeats were unstable during transmission. In 14 parent-child pairs, the average change of onset age was -6.4±7.3 years (mean±s.d.) in the child generation when compared with the parent generation. Of the 11 pairs analyzed, six showed expansion of inserted repeat length during transmission, and five showed contraction. On average, the inserted repeats expanded by 12.2±32.7 bp during transmission, but their mean length (with a 95% confidence interval) was not significantly different between parent and child generations. We consider that the length of the inserted repeats in SCA31 is changeable during transmission, but inter-generational instability is not marked, as far as the current sizing method can determine.

Natural History of Spinocerebellar Ataxia Type 31: a 4-Year Prospective Study.

Spinocerebellar ataxia type 31 (SCA31) is known as a late-onset, relatively pure cerebellar form of ataxia, but a longitudinal prospective study on the natural history of SCA31 has not been done yet. In this prospective cohort study, we enrolled 44 patients (mean ± standard deviation 73.6 ± 8.5 years) with genetically confirmed SCA31 from 10 ataxia referral centers in the Nagano area, Japan. Patients were evaluated every year for 4 years using the Scale for the Assessment and Rating of Ataxia (SARA) and the Barthel Index (BI). Of the 176 follow-up visits (91.5%), 161 were completed in this study. Five patients (11.4%) died during the follow-up period, and two patients (4.5%) were lost to follow-up. The annual progression of the SARA score was 0.8 ± 0.1 points/year and that of the BI was -2.3 ± 0.4 points/year (mean ± standard error). Shorter disease duration at baseline was associated with faster progression of the SARA score. Our study indicated the averaged clinical course of SCA31 as follows: the patients develop ataxic symptoms at 58.5 ± 10.3 years, become wheelchair bound at 79.4 ± 1.7 years, and died at 88.5 ± 0.7 years. Our prospective dataset provides important information for clinical trials of forthcoming disease-modifying therapies for cerebellar ataxia. It also represents a useful resource for SCA31 patients and their family members in genetic counseling sessions.

Principal component analysis for ataxic gait using a triaxial accelerometer.

BACKGROUND: It is quite difficult to evaluate ataxic gait quantitatively in clinical practice. The aim of this study was to analyze the characteristics of ataxic gait using a triaxial accelerometer and to develop a novel biomarker of integrated gate parameters for ataxic gait. METHODS: Sixty-one patients with spinocerebellar ataxia (SCA) or multiple system atrophy with predominant cerebellar ataxia (MSA-C) and 57 healthy control subjects were enrolled. The subjects were instructed to walk 10 m for a total of 12 times on a flat floor at their usual walking speed with a triaxial accelerometer attached to their back. Gait velocity, cadence, step length, step regularity, step symmetry, and degree of body sway were evaluated. Principal component analysis (PCA) was used to analyze the multivariate gait parameters. The Scale for the Assessment and Rating of Ataxia (SARA) was evaluated on the same day of the 10-m walk trial. RESULTS: PCA divided the gait parameters into four principal components in the controls and into two principal components in the patients. The four principal components in the controls were similar to those found in earlier studies. The second principal component in the patients had relevant factor loading values for gait velocity, step length, regularity, and symmetry in addition to the degree of body sway in the medio-lateral direction. The second principal component score (PCS) in the patients was significantly correlated with disease duration and the SARA score of gait (ρ = -0.363, p = 0.004; ρ = -0.574, p < 0.001, respectively). CONCLUSIONS: PCA revealed the main component of ataxic gait. The PCS of the main component was significantly different between the patients and controls, and it was well correlated with disease duration and the SARA score of gait in the patients. We propose that this score provides a novel method to assess the severity of ataxic gait quantitatively using a triaxial accelerometer.

Polyarteritis nodosa with central nervous system involvement mimicking relapsing-remitting multiple sclerosis.

We report a patient with polyarteritis nodosa (PN) who showed frequent episodes of acute-onset central nervous system (CNS) involvement mimicking relapsing-remitting multiple sclerosis (MS) for 22 years. Long-term use of oral prednisolone successfully avoided recurrence of neurological symptoms. PN can sometimes affect the CNS, and is an important item in the differential diagnosis of neurological manifestations with lesion dissemination in time and space, as seen in MS.

Low serum complements in idiopathic inflammatory myositis: clinical features and impact on the prognosis.

This study investigated the clinical features and prognostic relevance of decreased serum complement levels in patients with idiopathic inflammatory myositis (IIM). The clinical information of IIM patients with less than normal serum complement levels (L-Com) and that of those with normal serum complement levels (N-Com) was compared. In patients with interstitial lung disease (ILD), regression analyses were used to investigate the implication of L-Com in their PaO2/FiO2 (P/F) ratio. Prognostic outcomes of ILD were evaluated using the log-rank test. Of 94 IIM patients, 26 with L-Com (median age, 56.0 years) and 68 with N-Com (56.5 years) were included. The prevalence of women was significantly higher in patients with L-Com (92.3%) than in those with N-Com (67.6%). ILD was observed in 17 (65.4%) patients with L-Com and in 46 (67.6%) with N-Com. Among patients with ILD, the P/F ratio was significantly lower in those with L-Com than in those with N-Com. Serum C3 levels were correlated with decreased P/F ratio. Inferior prognosis of ILD was significantly demonstrated in patients with L-Com, especially in those positive for anti-melanoma differentiation-associated protein 5 antibody. L-Com may be implicated in reduced arterial oxygen levels and a poorer prognosis in patients with IIM-related ILD.

Neurofilament light chain as a biomarker for hereditary ATTR amyloidosis - correlation between neurofilament light chain and nerve conduction study.

BACKGROUND: Neurofilament light chain (NfL) is a biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the standard test for ATTRv neuropathy, has not been investigated. OBJECTIVE: Elucidate the correlation between NfL and NCS parameters. METHODS: 227 serum NfL measurements were performed in 45 ATTRv patients, 5 asymptomatic carriers, and 12 controls. Among them, 177 simultaneous analyses of NCS and NfL were conducted in 45 ATTRv patients. RESULTS: NfL levels of symptomatic patients were significantly higher than those of asymptomatic carriers and controls. Serum NfL levels were correlated with NCS parameters, especially compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, indicators of axonal damage. CMAP and/or SNAP amplitudes were undetectable in 9 patients (no-amplitude group) due to advanced neuropathy. NfL levels in the no-amplitude group were significantly higher than those in patients with detectable CMAP/SNAP. NfL levels significantly decreased with patisiran, although no significant changes were observed in CMAP and SNAP. CONCLUSIONS: NfL levels are found to be correlated with CMAP/SNAP amplitudes. Compared with NCS, NfL can be a more sensitive biomarker for detecting treatment response and active nerve damage even in patients with advanced neuropathy.

Genetic counselling for at-risk family members with hereditary transthyretin amyloidosis: data from a single-centre study.

BACKGROUND: Hereditary transthyretin-related amyloidosis is an autosomal dominant disorder. Recently, disease-modifying therapies (DMTs) have been developed. For at-risk individuals, genetic analysis aids in the early administration of medical care; however, few studies have evaluated the current status of genetic counselling and management of presymptomatic carriers of amyloidogenic variants. METHODS: We retrospectively evaluated the medical records of 202 consecutive participants. RESULTS: A total of 103 clients who received genetic counselling for predictive testing were at-risk, and 83 underwent predictive testing. Genetic testing results were positive in 33 patients, 11 of whom had confirmed amyloid deposition and were administered DMTs. For presymptomatic V30M (p.V50M) carriers, 32.0 ± 2.4 years (median ± standard error) was the age when amyloid deposition was first identified (95% confidence interval 27.4-36.6). Serum transthyretin (TTR) levels decreased serially with an estimated slope of -1.2 mg/dL/year. CONCLUSIONS: Our study suggests the clinical utility of management using a combination of predictive testing and monitoring methods. Psychosocial support should be considered with collaboration between geneticists/genetic counsellors and psychologists. For a more optimised protocol for monitoring and designing future interventional trials in presymptomatic carriers, prospective cohort studies are necessary to clarify the natural history, particularly in the early stages of the disease.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP): Estimation of pathological lesion stage from brain images.

BACKGROUND: Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a disease responsible for cognitive impairment in adult humans. It is caused by mutations in the colony stimulating factor 1 receptor gene (CSF1R) or alanyl-transfer (t) RNA synthetase 2 (AARS2) gene and affects brain white matter. Settlement of stages of the pathological brain lesions (Oyanagi et al. 2017) from the findings of brain imaging will be inevitably essential for prognostication. METHODS: MRI images of eight patients with ALSP were analyzed semiquantitatively. White matter degeneration was assessed on a scale of 0 to 4 (none, patchy, large patchy, confluent, and diffuse) at six anatomical points, and brain atrophy on a scale 0 to 4 (none, slight, mild, moderate, and severe) in four anatomical areas. The scores of the two assessments were then summed to give total MRI scores of 0-40 points. Based on the scores, the MRI features were classified as Grades (0-4). Regression analysis was applied to mutual association between mRS, white matter degeneration score, brain atrophy score, the total MRI score and disease duration. RESULTS: White matter degeneration score, brain atrophy score, and the total MRI score were significantly correlated with the disease duration. MRI Grades (2-4) based on the total MRI scores and the features of the images were well correlated with the pathological lesion stages (II - IV); i.e., 'large patchy' white matter degeneration in the frontal and parietal lobes (MRI Grade 2) corresponded to pathological Stage II, 'confluent' degeneration (Grade 3) to Stage III, and 'diffuse' degeneration (Grade 4) to Stage IV. CONCLUSION: MRI Grades (2-4) resulted from the total MRI scores were well correlated with the pathological lesion Stages (II - IV).

Quantitative assessment of the gait improvement effect of LSVT BIG® using a wearable sensor in patients with Parkinson's disease.

Background: The main effects of Lee Silvermann Voice Treatment-BIG® therapy (LSVT-BIG) on gait function are improvements in gait speed and stride length. Considering the mechanism of this improvement, LSVT-BIG may affect joint angles of the lower extremities. Therefore, further investigation of the effect of LSVT-BIG on gait function, especially joint angles, is needed. Methods: Patients with Parkinson's disease (PD) who were eligible for LSVT-BIG were recruited. We measured the following items pre- and post-LSVT-BIG: MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Functional Independence Measure (FIM), timed up and go test (TUG), and gait parameters using RehaGait®. Gait parameters included gait speed, stride duration and length, the standard deviation of stride duration and length, cadence, the ratio of the stance/swing phase, and the flexion and extension angles of the hip, knee, and ankle joints. Range of motion (ROM) was calculated as the difference of values between the maximum flexion and extension angles of each joint. Results: Twenty-four participants completed the LSVT-BIG. Significant improvement was observed in the MDS-UPDRS (mean changes: Part I, -2.4 points; Part II, -3.5 points; Part III -8.9 points), TUG (-0.61 s), gait speed (+0.13 m/s), stride length (+0.12 m), flexion and extension angles and ROM of the hip joints (flexion, +2.0°; extension, +2.0; ROM, +4.0°). Enlargement in ROM of the hip joint was strongly correlated with increase in gait speed and stride length (r = 0.755, r = 0.804, respectively). Conclusions: LSVT-BIG enlarged flexion and extension angles and ROM of the hip joint significantly. Change of ROM of the hip joint was directly related to the increase in stride length and gait speed observed in patients with PD after LSVT-BIG.

Distribution and progression of cerebral amyloid angiopathy in early-onset V30M (p.V50M) hereditary ATTR amyloidosis.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is becoming the most common and serious complications in long-lived hereditary ATTR amyloidosis patients. It is therefore imperative to elucidate the characteristics of ATTR-type CAA and develop useful biomarkers. METHODS: We enrolled 34 ATTRv amyloidosis patients with the V30M (p.V50M) variant for analysis with three-dimensional stereotactic surface projection z score imaging of Pittsburgh compound B (PiB)-PET. RESULTS: Eight patients exhibited central nervous system (CNS) symptoms. Seven patients suffered transient focal neurologic episodes, and 2 patients each experienced cerebellar haemorrhages or cognitive decline. The amount of 11C-PiB accumulation increased as a function of disease duration. 11C-PiB-PET abnormalities were seen at 8 years from onset and were associated with CNS manifestations from 12 years. The annual increase rate of the standardised uptake value ratio (SUVR) in female patients was significantly higher than in male patients. CNS amyloid deposition started in the upper middle surface of the cerebellar cortex, and then spread out over the entire surface of the cerebellum, Sylvian fissure, and anterior part of the longitudinal fissure of the cerebrum. CONCLUSIONS: PiB-PET is a useful biomarker for the early detection and treatment evaluation of ATTR-type CAA. Female gender is associated with more rapid progression of ATTR-type CAA.

Kinematic gait asymmetry assessment using joint angle data in patients with chronic stroke-A normalized cross-correlation approach.

BACKGROUND: Gait asymmetry is an important characteristic often studied in stroke patients. Several methods have been used to define gait asymmetry using joint angles. However, these methods may require normative data from healthy individuals as reference points. This study used normalized cross-correlation (CCnorm) to define kinematic gait asymmetry in individuals after stroke and investigated the usefulness of this assessment. RESEARCH QUESTION: Is the analysis of kinematic gait asymmetry based on joint angle data using CCnorm useful for gait assessment in patients with chronic stroke? METHODS: The study involved 12 patients with chronic stroke. A motion analysis system was used to record gait speed, hip joint angles, knee joint angles, ankle joint angles, stance time, and swing time. The CCnorm was calculated using the flexion-extension joint angles of hip, knee, and ankle in the sagittal plane to assess the degree of kinematic gait asymmetry. The symmetry ratio (SR) was calculated using stance and swing times to assess the degree of temporal gait asymmetry. Clinical outcomes were measured using the Fugl-Meyer Assessment for the lower extremity (FMA-LE), Berg Balance Scale (BBS), and Functional Independence Measure (FIM). RESULTS: Hip CCnorm was correlated with SRswing (r=-0.612, p < 0.05). Knee CCnorm was correlated with SRstance (r = 0.807, p < 0.01), SRswing (r=-0.752, p < 0.05), gait speed (r = 0.654, p < 0.05), BBS (r = 0.717, p < 0.01), and FIM (r = 0.735, p < 0.01). SIGNIFICANCE: Hip and knee joint CCnorm appear to be useful tools for the assessment of gait asymmetry in stroke patients. In addition, kinematic gait asymmetry of the knee joint could reflect physical function, balance, and activities of daily living. These findings underline the importance of using kinematic gait asymmetry assessment in chronic stroke patients.

Effect of the Synchronization-Based Control of a Wearable Robot Having a Non-Exoskeletal Structure on the Hemiplegic Gait of Stroke Patients.

We have been developing the robotic wear curara as both a welfare device and rehabilitation robot that assists the elderly and disabled. curara is aimed at user friendliness. We have, thus, chosen a non-exoskeleton structure made of a plastic so that the robot is as light in weight as possible and to minimize the restraining stress against natural human movement. We verified the assistance effect of curara on 15 hemiplegic patients with stroke by comparing gait parameters (i.e., velocity, step length, cadence, and symmetry of joint angles) among three conditions. The conditions were "without assistance" (i.e., a control mode that cancels frictional resistances in actuators), Condition A (where joint angles are enlarged but there is no change in gait cycle), and Condition B (where there is no change in joint angles but the gait cycle is shortened). curara improved the walking velocity by 19% and 27% under Conditions A and B, respectively. Improvements in step length and cadence were, respectively, 11% and 7% under Condition A and 14% and 11% under Condition B. Moreover, the two assistance conditions reduced the difference in joint angles between unaffected and paralyzed legs. We consider that curara will facilitate the rehabilitation of stroke patients.

Idiopathic cerebellar ataxia (IDCA): Diagnostic criteria and clinical analyses of 63 Japanese patients.

Cortical cerebellar atrophy (CCA) and multiple system atrophy with predominant cerebellar ataxia (MSA-C) are the two major forms of adult-onset sporadic ataxia. Contrary to MSA-C, there are neither diagnostic criteria nor neuroimaging features pathognomonic for CCA. Therefore, it is assumed that the category of CCA in the Japanese national registry include heterogeneous cerebellar ataxic disorders. To refine this category in more detail, we here used a clinical-based term, "idiopathic cerebellar ataxia (IDCA)", and proposed its diagnostic criteria. We collected 346 consecutive patients with the core features of the criteria (sporadic, insidious-onset and slowly progressive cerebellar ataxia in adults, and cerebellar atrophy on brain imaging). Of these, 212 (61.3%) were diagnosed with probable or possible MSA, and 30, who did not meet the diagnostic criteria for MSA at examination, were also excluded because of MRI findings suggestive of MSA. Twenty two were proven to have hereditary spinocerebellar ataxias by genetic testing, and 19 had secondary ataxias. Finally, the remaining 63 (18.2%) were diagnosed with IDCA. The mean (standard deviation) age at onset was 57.2 (10.8) years. Of these, 25 (39.7%) showed pure cerebellar ataxia, and the remaining 38 (60.3%) had some of extracerebellar features including abnormal tendon reflexes (46.0%), positive Babinski sign (9.5%), sensory disturbance (12.7%), cognitive impairment (9.5%), and involuntary movements (7.9%). Our results show that IDCA refined by the diagnostic criteria still includes clinically and genetically heterogeneous ataxic disorders. More extensive genetic analyses will be of significance for further clarification of this group.

Evaluation of walking smoothness using wearable robotic system curara® for spinocerebellar degeneration patients.

This paper aimed to verify the effectiveness of the wearable robotic system "curara" for patients with spinocerebellar degeneration (SCD) by evaluating walking smoothness. The curara system supports the wearer's gait using a synchronization control method that uses a neural oscillator based on a central pattern generator network. The system reflects the motional intention by adjusting the synchronization gains. This modifies the degree of interactive coordinated motion between the curara and the wearer. As a feasibility study, we evaluated the waking smoothness of 10 patients with SCD using three gain condition settings. Harmonic ratio (HR), which has been used extensively to quantify the smoothness during walking, was used to assess their walking. The results show that most HRs in the medio-lateral, anterior-posterior, and vertical directions using the three gain conditions were higher than those for patients not wearing the system. In particular, the increasing rates of the HR in all directions during the gait support were 11.1%, 23.4%, and 23.2% compared with unassisted walking, when the gain condition settings of hip and knee joints are set at 0.4 and 0.5, respectively. Consequently, these results verified the effectiveness of the curara system for patients with SCD.

Brain Biopsy Is More Reliable than the DNA test for JC Virus in Cerebrospinal Fluid for the Diagnosis of Progressive Multifocal Leukoencephalopathy.

The current standard diagnostic approach for progressive multifocal leukoencephalopathy (PML) is to perform a DNA test to identify the presence of the JC virus in cerebrospinal fluid (CSF). A 32-year-old woman with a 5-year history of systemic lupus erythematosus developed right hemiplegia and motor aphasia. MRI revealed a large white matter lesion in the left frontal lobe. JC virus DNA was undetectable in the CSF, but a brain biopsy showed typical histopathology and a high DNA load of the JC virus. The patient was treated with mefloquine and mirtazapine, and is currently alive at 24 months after onset. An early brain biopsy may therefore be important for making a timely diagnosis of PML.

Clinical assessment of standing and gait in ataxic patients using a triaxial accelerometer.

BACKGROUND: The aim of this study was to investigate the usefulness of a triaxial accelerometer for the clinical assessment of standing and gait impairment in ataxic patients quantitatively. Fifty-one patients with spinocerebellar ataxia (SCA) or multiple system atrophy with predominant cerebellar ataxia (MSA-C) and 56 healthy control subjects were enrolled. The subjects, with a triaxial accelerometer on their back, were indicated to stand for 30 s in four different conditions (eyes opened or closed, and feet apart or together) and then to walk 10 m for a total of 12 times on a flat floor at their usual walking speed. In standing analysis, the degree of body sway was assessed. In gait analysis, gait velocity, cadence, step length, step regularity (auto-correlation coefficient: AC), step repeatability (cross-correlation coefficient) and the degree of body sway (The ratio of root mean square in each direction to the root mean square vector magnitude: RMSR) were evaluated. RESULTS: The degree of body sway in each standing condition and all parameters in gait showed a significant difference between the patients and control subjects. The AC and RMSR values, as well as the Scale for the Assessment and Rating of Ataxia score, showed a strong correlation with disease duration. CONCLUSIONS: Various parameters obtained by a triaxial accelerometer can be sensitive and objective markers for the assessment and follow-up of standing and gait impairment in ataxic patients.

Marked and rapid regression of hepatic amyloid deposition in a patient with systemic light chain (AL) amyloidosis after high-dose melphalan therapy with stem cell transplantation.

A 52-year-old woman with a high serum alkaline phosphatase (ALP) level underwent a liver biopsy, which showed diffuse heavy deposition of Aκ amyloid, and was diagnosed as having immunoglobulin light chain (AL) amyloidosis. Although she received high-dose melphalan with stem cell transplantation and achieved a hematologic complete response (CR), her ALP level began to increase one year after treatment. Further examinations revealed that she was still in a CR state with dominant bone-type ALP, and re-biopsied liver specimens demonstrated marked regression of amyliod deposition, providing important evidence that the turnover of hepatic amyloid proteins can actually occur more rapidly than previously thought.