Factors associated with psychological distress in patients with amyotrophic lateral sclerosis: A retrospective medical records study.

OBJECTIVE: Although psychological distress is a prevalent issue among patients with amyotrophic lateral sclerosis (ALS) and can impact survival, the risk factors contributing to this distress remain insufficiently understood. METHODS: Patients with ALS who completed the Profile of Mood States (POMS) between June 2017 and March 2022 were included. Participants with moderate to severe cognitive decline were excluded, resulting in the recruitment of 121 patients. The associations between POMS profiles and clinical characteristics were analyzed. Physical motor symptoms were evaluated using the Revised ALS Functional Rating Scale (ALSFRS-R) for objective measurement and the 40-item ALS Assessment Questionnaire (ALSAQ-40) for subjective assessment. RESULTS: Our model, employing the ALSFRS-R, revealed significant factors associated with overall psychological distress, as assessed by the POMS, including upper limb symptoms, the presence of sleep apnea syndrome, older age at onset, and male sex, with an inverse association with tracheostomy. The POMS subscale scores revealed that anger and depression were significantly associated with upper limb symptoms. The second model, which employed subjective scales, yielded similar results, reinforcing the robustness of our findings. Moreover, subjective bulbar symptoms on the ALSAQ-40 were significantly associated with psychological distress, particularly in female patients. CONCLUSION: This study identified the main clinical characteristics significantly associated with psychological distress in patients with ALS. Our findings may be useful in developing individualized psychological management strategies for these patients.

Deep vein thrombosis and its risk factors in neurodegenerative diseases: A markedly higher incidence in Parkinson's disease.

BACKGROUND: Information on the incidence and risk factors of deep vein thrombosis (DVT) in neurodegenerative diseases is limited. We aimed to determine the incidence of DVT among neurodegenerative disorders (amyotrophic lateral sclerosis [ALS], Parkinson's disease [PD], multiple system atrophy [MSA], and progressive supranuclear palsy [PSP]-corticobasal syndrome [CBS]) and the risk factors for the development of DVT. METHODS: Overall, 229 hospitalized patients with neurodegenerative diseases (65 patients with ALS, 61 with PD, 53 with MSA, and 50 with PSP-CBS) were included in this study. D-dimer value and ultrasonography of the leg vein were assessed to determine the presence or absence of leg DVT. We compared the DVT incidence among each disease group. To identify the risk factors for DVT, a multivariate analysis was performed. RESULTS: Of 229 patients, 34 had leg DVT; the incidence was significantly higher in patients with PD (38%) than in those with ALS (2%), MSA (5%), or PSP-CBS (4%). Patients with DVT were older, had a smaller waist circumference, had a longer disease duration, and had a high blood pressure (BP) variability. Multivariate analysis revealed that a PD diagnosis and female sex, with a high BP variability were predictive of leg DVT. CONCLUSIONS: Among the neurodegenerative diseases, the DVT incidence was markedly higher in PD than in ALS, MSA, and PSP-CBS. Several risk factors have been identified in patients with leg DVT. Recognition of these risk factors will improve patient care and guide the appropriate use of anticoagulants.

Progressive medial temporal degeneration with TDP-43 pathology is associated with upper limb and bulbar onset types of amyotrophic lateral sclerosis.

OBJECTIVE: This study aimed to clarify the relationship between progressive medial temporal atrophy and onset subtype in patients with amyotrophic lateral sclerosis (ALS). METHODS: Medial temporal atrophy, ALS functional rating scale (ALSFRS), and cognitive function were assessed in 119 patients who were grouped into three ALS subtypes: bulbar, upper limb, and lower limb onset. Medial temporal atrophy, represented by a Z-score, was determined using an analysis software of magnetic resonance images known as the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD). Among 119 patients, 60 underwent follow-up VSRAD, ALSFRS, and cognitive testing. The sequential data were compared among onset subtypes. Furthermore, TDP-43 pathology was assessed in 20 autopsied patients (including seven who underwent VSRAD before death) to examine the relationships among medial temporal atrophy, onset subtypes, and severity of the hippocampal TDP-43 pathology. RESULTS: Multiple regression analysis revealed that the Z-score at baseline was associated with the age of onset and duration of illness. A high Z-score at baseline and the bulbar/upper limb subtypes affected the progression rate of Z-score. Pathological examination revealed increased hippocampal TDP-43 pathology score associated with bulbar and upper limb subtypes. Moreover, the Z-score before death correlated with the hippocampal TDP-43 pathology score. CONCLUSION: Medial temporal atrophy in ALS is associated with bulbar and upper limb onset subtypes. This progression may be related to the extent of TDP-43 pathology.

Efficacy and Safety of Ultrahigh-Dose Methylcobalamin in Early-Stage Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial.

Importance: The effectiveness of currently approved drugs for amyotrophic lateral sclerosis (ALS) is restricted; there is a need to develop further treatments. Initial studies have shown ultrahigh-dose methylcobalamin to be a promising agent. Objective: To validate the efficacy and safety of ultrahigh-dose methylcobalamin for patients with ALS enrolled within 1 year of onset. Design, Setting, and Participants: This was a multicenter, placebo-controlled, double-blind, randomized phase 3 clinical trial with a 12-week observation and 16-week randomized period, conducted from October 17, 2017, to September 30, 2019. Patients were recruited from 25 neurology centers in Japan; those with ALS diagnosed within 1 year of onset by the updated Awaji criteria were initially enrolled. Of those, patients fulfilling the following criteria after 12-week observation were eligible for randomization: 1- or 2-point decrease in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score, a percent forced vital capacity greater than 60%, no history of noninvasive respiratory support and tracheostomy, and being ambulatory. The target participant number was 64 in both the methylcobalamin and placebo groups. Patients were randomly assigned through an electronic web-response system to methylcobalamin or placebo. Interventions: Intramuscular injection of methylcobalamin (50-mg dose) or placebo twice weekly for 16 weeks. Main Outcomes and Measures: The primary end point was change in ALSFRS-R total score from baseline to week 16 in the full analysis set. Results: A total of 130 patients (mean [SD] age, 61.0 [11.7] years; 74 men [56.9%]) were randomly assigned to methylcobalamin or placebo (65 each). A total of 129 patients were eligible for the full analysis set, and 126 completed the double-blind stage. Of these, 124 patients proceeded to the open-label extended period. The least square means difference in ALSFRS-R total score at week 16 of the randomized period was 1.97 points greater with methylcobalamin than placebo (-2.66 vs -4.63; 95% CI, 0.44-3.50; P = .01). The incidence of adverse events was similar between the 2 groups. Conclusions and Relevance: Results of this randomized clinical trial showed that ultrahigh-dose methylcobalamin was efficacious in slowing functional decline in patients with early-stage ALS and with moderate progression rate and was safe to use during the 16-week treatment period. Trial Registration: ClinicalTrials.gov Identifier: NCT03548311.

Coexistence of neuronal intranuclear inclusion disease and amyotrophic lateral sclerosis: an autopsy case.

BACKGROUND: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease. Pathologically, it is characterized by eosinophilic hyaline intranuclear inclusions in the cells of the visceral organs as well as central, peripheral, and autonomic nervous system cells. Recently, a GGC repeat expansion in the NOTCH2NLC gene has been identified as the etiopathological agent of NIID. Interestingly, this GGC repeat expansion was also reported in some patients with a clinical diagnosis of amyotrophic lateral sclerosis (ALS). However, there are no autopsy-confirmed cases of concurrent NIID and ALS. CASE PRESENTATION: A 60-year-old Taiwanese woman reported a four-month history of progressive weakness beginning in the right foot that spread to all four extremities. She was diagnosed with ALS because she met the revised El Escorial diagnostic criteria for definite ALS with upper and lower motor neuron involvement in the cervical, thoracic, and lumbosacral regions. She died of respiratory failure at 22 months from ALS onset, at the age of 62 years. Brain magnetic resonance imaging (MRI) revealed lesions in the medial part of the cerebellar hemisphere, right beside the vermis (paravermal lesions). The subclinical neuropathy, indicated by a nerve conduction study (NCS), prompted a potential diagnosis of NIID. Antemortem skin biopsy and autopsy confirmed the coexistence of pathology consistent with both ALS and NIID. We observed neither eccentric distribution of p62-positive intranuclear inclusions in the areas with abundant large motor neurons nor cytopathological coexistence of ALS and NIID pathology in motor neurons. This finding suggested that ALS and NIID developed independently in this patient. CONCLUSIONS: We describe a case of concurrent NIID and ALS discovered during an autopsy. Abnormal brain MRI findings, including paravermal lesions, could indicate the coexistence of NIID even in patients with ALS showing characteristic clinical phenotypes.

Novel serum autoantibodies against ß-actin (ACTB) in amyotrophic lateral sclerosis.

To identify novel biomarkers using the serological analysis of recombinant cDNA expression libraries (SEREX) method and to evaluate their clinical significance in amyotrophic lateral sclerosis (ALS). Serum of ALS patients were screened for autoantibodies using the SEREX method. The identified autoantibodies were validated by measuring their serum levels in 70 ALS patients, 60 normal controls (NC), and 62 Parkinson disease (PD) patients using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA). The clinical relevance of these autoantibodies was investigated in ALS patients. SEREX identified 16 candidate antigens including ß-actin (ACTB) in addition to proteasome subunit alpha type 7 (PSMA7) that we previously reported, and serum levels of antibodies against ACTB, were significantly higher in ALS patients than in NC (p < 0.001) and PD patients (p = 0.001). Moreover, serum levels of anti-ACTB antibody were higher in advanced stage ALS patients (Stage 4 on the King's ALS clinical staging) and in those with more severe disability (ALS Functional Rating Scale revised [ALSFRS-R] score < 40.5) compared to early stage (Stage 2 [2nd region involved)]) patients and those with less severe disability (ALSFRS-R score ≥ 40.5) (p = 0.003, p = 0.014). Anti-ACTB antibody levels were also negatively correlated with ALSFRS-R score (ρ = -0.409, p = 0.001), but positively correlated with clinical disease stage (ρ = 0.355, p = 0.003), and showed a weak positive correlation with disease duration (ρ = 0.294, p = 0.014). Anti-ACTB antibodies may be a potential biomarker of ALS could indicate disease severity.

Cognitive and behavioral status in Japanese ALS patients: a multicenter study.

OBJECTIVES: Amyotrophic lateral sclerosis (ALS) patients may present with cognitive and behavioral abnormalities similar to frontotemporal dementia (FTD). In this multicenter study we examined Japanese ALS patients with and without FTD in order to characterize the full extent of cognitive and behavioral abnormalities, including associations with functional motor status, anxiety and depression. METHODS: Patients were evaluated using the Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB), Hospital Anxiety and Depression Scale, ALS Functional Rating Scale-Revised, spirometry, and verbal fluency tests. Caregivers were asked to complete the ALS-FTD-Questionnaire (ALS-FTD-Q), a behavioral screen. We defined severe cognitive impairment (MoCA < 21 or FAB < 11), mild impairment (11 ≤ MoCA ≤ 25 or 11 ≤ FAB ≤ 15), and normal cognition (MoCA > 25 or FAB > 15). Severe and mild behavioral impairments and normal behavior were defined by the ALS-FTD-Q scores. RESULTS: In 145 ALS patients, better cognitive scores were correlated with earlier age at onset, whereas a worse behavioral score was associated with a longer disease duration and higher level of anxiety and depression. Around seventy percent of all ALS patients showed mild (40-45%) or severe cognitive impairment with cognitive impairment outnumbering behavioral impairment fivefold. Cognitive functions were more impaired in patients with age of onset over 65 years, while behavioral scores were not related to age. CONCLUSIONS: Considering the high prevalence of in particular cognitive impairment, and the diversity of impairments, the cognitive and behavioral aspects of Japanese ALS patients should be given more attention clinically.

The Japanese Early-Stage Trial of High-Dose Methylcobalamin for Amyotrophic Lateral Sclerosis (JETALS): Protocol for a Randomized Controlled Trial.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects the upper and lower motor neurons. Currently, only riluzole and edaravone are approved as drugs to treat ALS and new agents with larger effect sizes are warranted. Exploratory analyses in our previous study (study ID #E0302-J081-761) have suggested that high-dose methylcobalamin (E0302) prolonged the overall survival of ALS patients and suppressed ALS progression in patients with a disease duration of less than 12 months. OBJECTIVE: This clinical trial aims to evaluate the efficacy and safety of E0302 for treatment of ALS patients within one year of onset. METHODS: The Japanese early-stage trial of high-dose methylcobalamin for ALS (JETALS) is a prospective, multicenter, placebo-controlled, double-blind, randomized phase III study conducted at 24 tertiary neurology centers and is funded by the Japan Agency for Medical Research and Development. A total of 128 ALS patients within one year of onset were randomized at a 1:1 ratio to receive intramuscular injection with E0302 50 mg or placebo twice a week for 16 weeks. The primary endpoint is changes in the ALS Functional Rating Scale-Revised (ALSFRS-R) total score at 16 weeks. If patients wish to receive E0302 50 mg after the double-blind administration period, E0302 will be provided to them until March 2020 during the continuous administration period. RESULTS: This study began in October 2017 and is being conducted at 24 participating institutions in Japan. The study is in progress and the patient enrollment period is scheduled to end in August 2019, with follow-up scheduled to end in March 2020. CONCLUSIONS: This study is being performed to revalidate the efficacy and safety of E0302 in patients with early-stage ALS in the first year of symptom onset. If positive results are obtained, the aim is to apply for E0302 approval as a new drug for the treatment of ALS. TRIAL REGISTRATION: ClinicalTrials.gov NCT03548311; https://clinicaltrials.gov/ct2/show/NCT03548311 (Archived by WebCite at http://www.webcitation.org/74Fw3rDzb). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/12046.

Novel autoantibodies against the proteasome subunit PSMA7 in amyotrophic lateral sclerosis.

OBJECTIVE: To identify autoantibodies using sera from ALS patients and elucidate their roles in disease pathology. METHODS: An immunological screening was performed with a phage expression library SEREX method using sera from 3 ALS patients to identify ALS-related autoantibodies. Levels of antibodies identified by SEREX were measured in 33 ALS patients and 30 normal controls (NCs) by AlphaLISA using recombinant non-full-length proteins. The results were then validated by ELISA using full-length proteins in 71 ALS patients, 30 NCs and 34 disease controls (DCs). The relationship between the titres and clinical profiles of ALS patients were examined. RESULTS: Four autoantibodies identified by SEREX were proteasome subunit alpha type 7 (PSMA7), vimentin, hydroxymethylbilane synthase and TBC1 domain family member 2 (TBC1D2). AlphaLISA revealed that only the anti-PSMA7 and anti-TBC1D2 levels were significantly different between the ALS and NCs groups. ELISA showed that only the levels of antibody against PSMA7, involved in protein degradation by the ubiquitin-proteasome pathway (UPP), were higher in the ALS group than both the NC (P < .01) and DC (P = .034) groups. Anti-PSMA7 levels tended to be negatively correlated with the logarithm of disease duration (P = .052) and were significantly positively correlated with the logarithm of creatine kinase levels (P = .011). The anti-PSMA7 antibody levels were different between patients with and without dysphagia (P < .01). CONCLUSIONS: Serum anti-PSMA7 antibody might be a disease-promoting factor in early-stage ALS and might be a biomarker of ALS. Anti-PSMA7 autoantibody might contribute to the pathogenesis of ALS, possibly via its role in the UPP.

Altered cerebral blood flow in the anterior cingulate cortex is associated with neuropathic pain.

OBJECTIVE: To assess the cerebral blood flow (CBF) in patients with diabetic neuropathic pain, and its changes after duloxetine therapy. METHODS: Using iodine-123-N-isopropyl-p-iodoamphetamine single-photon emission computed tomography (IMP-SPECT), we performed a cross-sectional study of 44 patients with diabetes, and compared CBF in those with (n = 24) and without neuropathic pain (n = 20). In patients with neuropathic pain, we also longitudinally assessed changes in CBF 3 months after treatment with duloxetine. RESULTS: IMP-SPECT with voxel-based analyses showed a significant increase in cerebral blood flow in the right anterior cingulate cortex and a decrease in the left ventral striatum in patients with neuropathic pain, compared with those without pain. After duloxetine treatment, volume of interest analyses revealed a decrease in cerebral blood flow in the anterior cingulate cortex in patients with significant pain relief but not in non-responders. Furthermore, voxel-based whole brain correlation analyses demonstrated that greater baseline CBF in the anterior cingulate cortex was associated with better pain relief on the numerical rating scale. CONCLUSIONS: Our results suggest that the development of neuropathic pain is associated with increased activity in the anterior cingulate cortex, and greater baseline activation of this region may predict treatment responsiveness to pharmacological intervention. TRIAL REGISTRATION NUMBER: UMIN000017130;Results.

Pain-related evoked potentials after intraepidermal electrical stimulation to Aδ and C fibers in patients with neuropathic pain.

Neuropathic pain can result from neuronal hyperexcitability and complex interactions of the nociceptive pathways. Intraepidermal electrical stimulation (IES) is a novel technique that can selectively activate Aδ and C fibers. To investigate patterns of changes in Aδ- and C-mediated brain responses in patients with neuropathic pain using IES, we recorded pain-related evoked potential (PREP) after IES of Aδ and C fibers in 20 patients with neuropathic pain and 15 age-matched healthy volunteers. We evaluated PREP latencies, amplitudes, and amplitude ratios of PREPs after C/Aδ-fiber stimulation. PREP amplitudes after Aδ-fiber stimulation tended to be smaller in the patient group, whereas there were no significant differences in amplitudes after C-fiber stimulation between the patient and normal control groups. PREP amplitude ratios after C/Aδ-fiber stimulation were significantly greater in the patient group than in the control group, and the higher ratio tended to be associated with a greater visual analog scale score. Patients with neuropathic pain had a tendency towards decreased Aδ amplitudes and significantly increased C/Aδ PREP amplitude ratios and this ratio appeared to be associated with the intensity of pain. Our findings suggest that decreased inhibition of the Aδ to C nociceptive systems is associated with generation of neuropathic pain.

Does Anticholinergic Activity Affect Neuropathology? Implication of Neuroinflammation in Alzheimer's Disease.

One characteristic neuropathological feature of Alzheimer's disease (AD) is profound neuronal loss in the nucleus basalis of Meynert, the major source of cholinergic innervation of the cerebral cortex. Clinically, anticholinergic activity causes a decline in cognitive function and increases the risk of dementia, thus possibly enhancing AD pathologies and neurodegeneration. Until now there has been insufficient human neuropathological data to support this conclusion. Experimental studies using a tauopathy mouse model demonstrated anticholinergics enhanced tau pathology and neurodegeneration corresponding to central anticholinergic activity. Additionally, donepezil, a cholinesterase inhibitor, ameliorated tau pathology and neurodegeneration in the same mouse model. These results indicate the balance between cholinergic and anticholinergic activities might affect neurodegeneration. Importantly, neurodegeneration observed in the mouse model seemed to correspond to the distribution of microglial activation, and it was reported that neuroinflammation plays an important role in the pathomechanism of AD, while anticholinergic activity augments inflammatory responses. Moreover, some studies indicated ß-amyloid itself depletes cholinergic function similarly to anticholinergic activity. Thus, anticholinergic activity might initiate and/or accelerate AD pathology. Limited human data support the conclusion that anticholinergic activity enhances AD-related neuropathology and neurodegeneration. However, experimental data from a tauopathy mouse model indicated anticholinergic activity might enhance neurodegeneration with enhanced neuroinflammation including microglial activation.

Altered axonal excitability properties and nerve edema in POEMS syndrome.

OBJECTIVE: POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome is a rare cause of demyelinating neuropathy with upregulation of vascular endothelial growth factor (VEGF). This study aimed to elucidate axonal excitability properties and their relation to VEGF levels and nerve edema in POEMS neuropathy. METHODS: Axonal excitability measurement and nerve ultrasound were performed in the median nerve of 33 patients with POEMS syndrome. Serum VEGF levels were measured by ELISA. RESULTS: Compared with normal subjects (n=87), POEMS patients showed longer strength-duration time constant, fanning-out of threshold electrotonus curves, and greater threshold changes in a hyperpolarizing current-threshold relationship. Nerve ultrasound showed significant enlargement in POEMS patients. Serum VEGF levels and the extent of nerve edema partly correlated with nerve conduction slowing, as well as persistent sodium currents and inward rectification. CONCLUSIONS: In POEMS syndrome, patterns of changes in excitability properties could suggest increased persistent sodium currents, and impaired potassium and inward rectifying channels. The findings were not consistent with depolarization due to nerve edema and compression ischemia. SIGNIFICANCE: In addition to demyelination, nerve edema induced by upregulated VEGF, and upregulated inflammatory cytokines could modulate profiles of POEMS neuropathy.

Effects of low frequency filtering on distal compound muscle action potential duration for diagnosis of CIDP: A Japanese-European multicenter prospective study.

OBJECTIVE: The duration of the distal compound muscle action potential (DCMAP) is a useful index to detect demyelination in the distal nerve segments. However in published electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP), the cut-off values of DCMAP duration are defined using an EMG low frequency filter of only 20 Hz. We aimed to provide widely-available reference data using several low cut filters. METHODS: In 13 Japanese and European tertiary centers, DCMAP duration data using 2, 5, 10, and 20 Hz low frequency filters were prospectively collected from 147 normal controls, 59 patients with typical CIDP, and 100 with diabetic polyneuropathy. Optimal cut-off values were calculated with receiver-operating characteristic curves, offering 100% specificity versus normal controls. RESULTS: The higher low frequency filter was associated with significantly shorter DCMAP duration in all groups. For CIDP diagnosis, the calculated cut-off values had a sensitivity ranging from 51% to 66%, and a specificity versus diabetic neuropathy from 96% to 98%. CONCLUSIONS: Our results show that DCMAP duration is largely dependent on low frequency filter settings, but is a useful index for CIDP diagnosis when the cut-off values are properly determined at each filter setting. SIGNIFICANCE: Our data provide the systematic reference values of DCMAP duration for CIDP diagnosis available for most EMG laboratories.

Different electrophysiological profiles and treatment response in 'typical' and 'atypical' chronic inflammatory demyelinating polyneuropathy.

BACKGROUND: Chronic inflammatory demyelinating polyneuropathy (CIDP) is currently classified into 'typical' CIDP and 'atypical' subtypes such as multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). OBJECTIVES: To assess the frequency of CIDP subtypes, and to elucidate clinical and electrophysiological features, and treatment response in each subtype. METHODS: We reviewed data from 100 consecutive patients fulfilling criteria for CIDP proposed by the European Federation of Neurological Societies and the Peripheral Nerve Society. The Kaplan-Meier curve was used to estimate long-term outcome. RESULTS: Patients were classified as having typical CIDP (60%), MADSAM (34%), demyelinating acquired distal symmetric neuropathy (8%) or pure sensory CIDP (1%). Compared with patients with MADSAM, patients with typical CIDP showed more rapid progression and severe disability, and demyelination predominant in the distal nerve segments. MADSAM was characterised by multifocal demyelination in the nerve trunks. Abnormal median-normal sural sensory responses were more frequently found for typical CIDP (53% vs 13%). Patients with typical CIDP invariably responded to corticosteroids, immunoglobulin or plasmapheresis, whereas patients with MADSAM were more refractory to these treatments. The Kaplan-Meier analyses showed that 64% of patients with typical CIDP and 41% of patients with MADSAM had a clinical remission 5 years later (p=0.02). CONCLUSIONS: Among the CIDP spectrum, typical CIDP and MADSAM are the major subtypes, and their pathophysiology appears to be distinct. In typical CIDP, the distal nerve terminals and possibly the nerve roots, where the blood-nerve barrier is anatomically deficient, are preferentially affected, raising the possibility of antibody-mediated demyelination, whereas cellular immunity with breakdown of the barrier may be important in MADSAM neuropathy.

Duration of the distal compound muscle action potential for diagnosis of chronic inflammatory demyelinating polyneuropathy: effects of low-cut filters.

PURPOSE: In current electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy, the cutoff values of distal compound muscle action potential (DCMAP) duration are defined using electromyogram low-cut filter setting of 20 Hz. We aimed to assess effects of low-cut filter on DCMAP duration (10 vs. 20 Hz). METHODS: We prospectively measured DCMAP duration in 130 normal controls and 42 patients, fulfilling diagnostic criteria for typical chronic inflammatory demyelinating polyneuropathy by European Federation of Neurological Societies/Peripheral Nerve Society. RESULTS: Distal compound muscle action potential duration was significantly shortened with 20-Hz than 10-Hz filtering. When the cutoff values were defined as the upper limit of normal (ULN, mean + 2.5SD), the sensitivity/specificity was 67%/95% in 10-Hz recordings, and 69%/95% in 20-Hz recordings. This diagnostic accuracy was similar to that defined by receiver operating characteristic analyses. CONCLUSIONS: Distal compound muscle action potential duration significantly affected by the low-cut electromyogram filter setting, but with at least 10 and 20 Hz, the diagnostic accuracy is similar.

Safety and efficacy of intravenous ultra-high dose methylcobalamin treatment for peripheral neuropathy: a phase I/II open label clinical trial.

OBJECTIVE: No clinically effective treatment for promoting peripheral axonal regeneration has yet been established. Several experimental studies in vitro and in vivo have shown that a high dose of methylcobalamin (MeCbl), an analogue of vitamin B12, promotes axonal growth in peripheral nerve injury. We herein assessed the safety and efficacy of an ultra-high dose MeCbl treatment for patients with peripheral neuropathy and chronic axonal degeneration. METHODS: Fourteen patients with immune-mediated or hereditary neuropathy in the chronic progressive or stable phase were enrolled. MeCbl, 25 mg/day for 10 days followed by monthly 25 mg for 5 months, was intravenously administered. The patients were evaluated before and 1 year following treatment. The primary endpoints were safety and improvement in the Medical Research Council (MRC) sum score in at least two muscles of the 20 muscles. This trial is registered with the University Hospital Medical Information Network (UMIN) Center in Japan under the ID: UMIN000009359. RESULTS: There were no adverse effects in twelve of the patients, whereas treatment was discontinued in two patients who had seborrheic dermatitis at 3 months and respiratory tract infection at 2 months, respectively. Therefore, twelve patients were evaluated for the primary outcomes; the MRC sum score was improved in seven of the patients and unchanged or worsened in the remaining five patients. CONCLUSION: Intravenous ultra-high dose MeCbl treatment is a safe and potentially efficacious therapy for patients with peripheral neuropathy and chronic axonal degeneration.

Bortezomib-induced neuropathy: axonal membrane depolarization precedes development of neuropathy.

OBJECTIVE: Bortezomib is a proteasome inhibitor with high efficacy for multiple myeloma but with severe peripheral neurotoxicity, leading to dose modification and severe neurological disability. This study aimed to investigate the pathophysiology of bortezomib-induced neuropathy. METHODS: Threshold tracking was used to assess the excitability of sensory and motor axons. Measurements were sequentially performed before and after bortezomib treatment in nine patients with newly diagnosed multiple myeloma. RESULTS: In total, 67% of patients finally developed symptomatic neuropathy. Changes in sensory axonal excitability indices readily occurred after the first course of administration. Patterns of changes in excitability indices suggest membrane depolarization (decreased superexcitability, P<0.001; decreased depolarizing threshold electrotonus 90-100ms, P=0.02). Abnormalities in nerve conduction parameters suggestive of axonal degeneration appeared after the second course of treatment. CONCLUSIONS: Bortezomib induces a depolarizing shift in resting membrane potential prior to the development of neuropathy. Membrane depolarization could be associated with impairment of electrogenic Na(+)-K(+)-ATPase-dependent pump caused by toxic effects of bortezomib on mitochondria. SIGNIFICANCE: Axonal depolarization and hyperexcitability might enhance neurodegeneration in bortezomib-induced neuropathy.

Prominent fatigue in spinal muscular atrophy and spinal and bulbar muscular atrophy: evidence of activity-dependent conduction block.

OBJECTIVES: To clarify whether patients with spinal muscular atrophy (SMA) or spinal and bulbar muscular atrophy (SBMA) suffer disabling muscle fatigue, and whether activity-dependent conduction block (ADCB) contributes to their fatigue. ADCB is usually caused by reduced safety factor for impulse transmission in demyelinating diseases, whereas markedly increased axonal branching associated with collateral sprouting may reduce the safety factor in chronic lower motor neuron disorders. METHODS: We assessed the fatigue severity scale (FSS) in 22 patients with SMA/SBMA, and in 100 disease controls (multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy (CIDP), and axonal neuropathy). We then performed stimulated-single fibre electromyography (s-SFEMG) in the extensor digitorum communis (EDC) muscle of 21 SMA/SBMA patients, 6 CIDP patients, and 10 normal subjects. RESULTS: The FSS score was the highest in SMA/SBMA patients [4.9 ± 1.1 (mean ± SD)], with 81% of them complaining of disabling fatigue, compared with normal controls (3.5 ± 1.0), whereas patients with multiple sclerosis (4.3 ± 1.6), myasthenia gravis (4.0 ± 1.6) or CIDP (4.3 ± 1.4) also showed higher FSS score. When 2000 stimuli were delivered at 20 Hz in s-SFEMG, conduction block of single motor axons developed in 46% of patients with SMA/SBMA, and 40% of CIDP patients, but in none of the normal controls. CONCLUSION: SMA/SBMA patients frequently suffer from disabling fatigue presumably caused by ADCB induced by voluntary activity. SIGNIFICANCE: ADCB could be the mechanism for muscle fatigue in chronic lower motor neuron diseases.