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Clonal hematopoiesis (CH) is a risk factor for the development of therapy-related myelodysplastic syndromes (tMDS) and acute myeloid leukemia (tAML). Adoption of targeted-immunotherapeutics since 2011, may alter the risk of CH progression to tMDS/AML. To study this, we evaluated risk of tMDS and tAML in 667 588 ≥ 1-year survivors of non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), melanoma and multiple-myeloma (MM) diagnosed during: 2000–2005, 2006–2010 and 2011–2016. The risk of tMDS increased significantly after NSCLC across all time periods (Ptrend = 0.002) while tAML risk decreased from 2006–2010 to 2011–2016, coinciding with increasing use of non-chemotherapeutic agents. tAML risk after RCC decreased (Ptrend = 0.007) whereas tMDS risk did not significantly change over time. After melanoma, tMDS and tAML risks were similar to the general population. tMDS and tAML risk after MM increased from the first to second time-period, however, only risk of tMDS decreased during last period. We report diverging trends in the risk of tAML and tMDS after adoption of modern cancer therapies for specific cancers. It is imperative to further explore impact of contemporary treatment strategies on clonal evolution. Modern treatments via their discrete mechanism of actions on pre-existing CH may alter the risk of subsequent tMDS and tAML.

The optimal approach to combine gemtuzumab-ozogamicin (GO) with various chemotherapy backbones and other newer agents safely remains to be determined. We performed a retrospective analysis of the safety and outcomes of newly diagnosed adult AML patients treated with GO in combination with intensified versus standard anthracycline doses (i.e. daunorubicin dose 90 mg/m(2) vs 60 mg/m(2)) ± FLT3 inhibitors. Chi-square test and Mann Whitney U test were used to compare categorical and continuous data. Survival estimates were calculated by Kaplan–Meier method and survival comparisons made using log-rank test. We report an ORR of 97% in newly diagnosed AML patients (n=37) with a median age of 54 (range, 19–75) years treated with GO in combination with standard induction. All eleven patients (100%) receiving GO plus daunorubicin dose 90 mg/m(2) as part of 7+3 induction achieved CR vs 91% (20/22) CR in the standard daunorubicin 60 mg/m(2) dose group (p=NS), No increased toxicity was noted with the higher daunorubicin dose or when GO and 7+3 were combined with FLT3 inhibitors in younger patients (age

Contains fulltext : 241356.pdf (Publisher’s version ) (Open Access) Centronuclear myopathy (CNM) is a genetically heterogeneous congenital myopathy characterized by muscle weakness, atrophy, and variable degrees of cardiorespiratory involvement. The clinical severity is largely explained by genotype (DNM2, MTM1, RYR1, BIN1, TTN, and other rarer genetic backgrounds), specific mutation(s), and age of the patient. The histopathological hallmark of CNM is the presence of internal centralized nuclei on muscle biopsy. Information on the phenotypical spectrum, subtype prevalence, and phenotype-genotype correlations is limited. To characterize CNM more comprehensively, we retrospectively assessed a national cohort of 48 CNM patients (mean age = 32 ± 24 years, range 0-80, 54% males) from the Netherlands clinically, histologically, and genetically. All information was extracted from entries in the patient's medical records, between 2000 and 2020. Frequent clinical features in addition to muscle weakness and hypotonia were fatigue and exercise intolerance in more mildly affected cases. Genetic analysis showed variants in four genes (18 DNM2, 14 MTM1, 9 RYR1, and 7 BIN1), including 16 novel variants. In addition to central nuclei, histologic examination revealed a large variability of myopathic features in the different genotypes. The identification and characterization of these patients contribute to trial readiness.

PURPOSE Hematologic toxic effects of peptide receptor radionuclide therapy (PRRT) can be permanent. Patients with underlying clonal hematopoiesis (CH) may be more inclined to develop hematologic toxicity after PRRT. However, this association remains understudied. MATERIALS AND METHODS We evaluated pre- and post-PRRT blood samples of patients with neuroendocrine tumors. After initial screening, 13 cases of interest were selected. Serial blood samples were obtained on 4 of 13 patients. Genomic DNA was analyzed using a 100-gene panel. A variant allele frequency cutoff of 1% was used to call CH. RESULT Sixty-two percent of patients had CH at baseline. Persistent cytopenias were noted in 64% (7 of 11) of the patients. Serial sample analysis demonstrated that PRRT exposure resulted in clonal expansion of mutant DNA damage response genes ( TP53, CHEK2, and PPM1D) and accompanying cytopenias in 75% (3 of 4) of the patients. One patient who had a normal baseline hemogram and developed persistent cytopenias after PRRT exposure showed expansion of mutant PPM1D (variant allele frequency increased to 20% after exposure from < 1% at baseline). In the other two patients, expansion of mutant TP53, CHEK2, and PPM1D clones was also noted along with cytopenia development. CONCLUSION The shifts in hematopoietic clonal dynamics in our study were accompanied by emergence and persistence of cytopenias. These cytopenias likely represent premalignant state, as PPM1D-, CHEK2-, and TP53-mutant clones by themselves carry a high risk for transformation to therapy-related myeloid neoplasms. Future studies should consider CH screening and longitudinal monitoring as a key risk mitigation strategy for patients with neuroendocrine tumors receiving PRRT.

BackgroundHigh bone mass (HBM, BMD Z-score ≥ + 3.2) and cam morphology (bulging of lateral femoral head) are associated with greater odds of prevalent radiographic hip osteoarthritis (rHOA). As cam morphology is itself a manifestation of increased bone deposition around the femoral head, it is conceivable that cam morphology may mediate the relationship between HBM and rHOA. We therefore aimed to determine if individuals with HBM have increased odds of prevalent cam morphology. In addition, we investigated whether the relationship between cam and prevalent and incident osteoarthritis was preserved in a HBM population.MethodsIn the HBM study, a UK based cohort of adults with unexplained HBM and their relatives and spouses (controls), we determined the presence of cam morphology using semi-automatic methods of alpha angle derivation from pelvic radiographs. Associations between HBM status and presence of cam morphology, and between cam morphology and presence of rHOA (or its subphenotypes: osteophytes, joint space narrowing, cysts, and subchondral sclerosis) were determined using multivariable logistic regression, adjusting for age, sex, height, weight, and adolescent physical activity levels. The association between cam at baseline and incidence of rHOA after an average of 8 years was determined. Generalised estimating equations accounted for individual-level clustering.ResultsThe study included 352 individuals, of whom 235 (66.7%) were female and 234 (66.5%) had HBM. Included individuals contributed 694 hips, of which 143 had a cam deformity (20.6%). There was no evidence of an association between HBM and cam morphology (OR = 0.97 [95% CI: 0.63–1.51],p = 0.90) but a strong relationship was observed between cam morphology and rHOA (OR = 3.96 [2.63–5.98],p = 5.46 × 10–11) and rHOA subphenotypes joint space narrowing (OR = 3.70 [2.48–5.54],p = 1.76 × 10–10), subchondral sclerosis (OR = 3.28 [1.60–6.60],p = 9.57 × 10–4) and osteophytes (OR = 3.01 [1.87–4.87],p = 6.37 × 10–6). Cam morphology was not associated with incident osteoarthritis (OR = 0.76 [0.16–3.49],p = 0.72).ConclusionsThe relationship between cam morphology and rHOA seen in other studies is preserved in a HBM population. This study suggests that the risk of OA conferred by high BMD and by cam morphology are mediated via distinct pathways.

Myotonic dystrophy type 1 (DM1) is caused by a CTG trinucleotide repeat expansion on chromosome 19q13.3. While DM1 premutation (36–50 repeats) and protomutation (51–80 repeats) allele carriers are mostly asymptomatic, offspring is at risk of inheriting expanded, symptom-associated, (CTG)n repeats of n > 80. In this study we aimed to evaluate the intergenerational instability of DM1 pre- and protomutation alleles, focussing on the influence of parental gender. One hundred and forty-six parent–child pairs (34 parental premutations, 112 protomutations) were retrospectively selected from the DM1 patient cohort of the Maastricht University Medical Center+. CTG repeat size of parents and children was determined by (triplet-primed) PCR followed by fragment length analysis and Southern blot analysis. Fifty-eight out of eighty-one (71.6%) paternal transmissions led to a (CTG)n repeat of n > 80 in offspring, compared with 15 out of 65 (23.1%) maternal transmissions (p < 0.001). Repeat length instability occurred for paternal (CTG)n repeats of n ≥ 45, while maternal instability did not occur until (CTG)n repeats reached a length of n ≥ 71. Transmission of premutations caused (CTG)n repeats of n > 80 in offspring only when paternally transmitted (two cases), while protomutations caused (CTG)n repeats of n > 80 in offspring in 71 cases, of which 56 (78.9%) were paternally transmitted. In conclusion, our data show that paternally transmitted pre- and protomutations were more unstable than maternally transmitted pre- and protomutations. For genetic counseling, this implies that males with a small DMPK mutation have a higher risk of symptomatic offspring compared with females. Consequently, we suggest addressing sex-dependent factors in genetic counseling of small-sized CTG repeat carriers.

Objectives:\ud The objective of this cross‐sectional, observational study was to investigate performance of activities of daily living in patients with myotonic dystrophy type 1 (DM1).\ud \ud Materials and Methods:\ud Adults with genetically confirmed DM1 were recruited from Newcastle University (Newcastle upon Tyne, UK) and University College London Hospitals NHS Foundation Trust (London, UK). Data on activities of daily living were recorded through the DM1‐ActivC (scale scores range between 0 and 100, where a higher/lower score indicates a higher/lower ability).\ud \ud Results:\ud Our sample comprised 192 patients with DM1 (mean age: 46 years; 51% female). Patients reported most difficulties with running, carrying and putting down heavy objects, and standing on one leg, and least difficulties with eating soup, washing upper body, and taking a shower. Irrespective of the disease duration (mean: 20 years), most patients were able to perform basic and instrumental activities of daily living (eg personal hygiene and grooming, showering, eating, cleaning and shopping), with the exception of functional mobility/transfer tasks (eg walking uphill and running). The mean DM1‐ActivC total score was estimated at 71 (95% CI: 68‐74). Estimated progenitor cytosine‐thymine‐guanine repeat length and age explained 27% of the variance in DM1‐ActivC total scores (P < .001).\ud \ud Conclusions:\ud We show that DM1 impairs performance of activities of daily living, in particular those requiring a high degree of muscle strength, stability and coordination. Yet, across the evolution of the disease, the majority of patients will still be able to independently perform most basic and instrumental activities of daily living.

Summary Background Treatment with one standard dose (2 g/kg) of intravenous immunoglobulin is insufficient in a proportion of patients with severe Guillain-Barre syndrome. Worldwide, around 25% of patients severely affected with the syndrome are given a second intravenous immunoglobulin dose (SID), although it has not been proven effective. We aimed to investigate whether a SID is effective in patients with Guillain-Barre syndrome with a predicted poor outcome. Methods In this randomised, double-blind, placebo-controlled trial (SID-GBS), we included patients (≥12 years) with Guillain-Barre syndrome admitted to one of 59 participating hospitals in the Netherlands. Patients were included on the first day of standard intravenous immunoglobulin treatment (2 g/kg over 5 days). Only patients with a poor prognosis (score of ≥6) according to the modified Erasmus Guillain-Barre syndrome Outcome Score were randomly assigned, via block randomisation stratified by centre, to SID (2 g/kg over 5 days) or to placebo, 7–9 days after inclusion. Patients, outcome adjudicators, monitors, and the steering committee were masked to treatment allocation. The primary outcome measure was the Guillain-Barre syndrome disability score 4 weeks after inclusion. All patients in whom allocated trial medication was started were included in the modified intention-to-treat analysis. This study is registered with the Netherlands Trial Register, NTR 2224/NL2107. Findings Between Feb 16, 2010, and June 5, 2018, 327 of 339 patients assessed for eligibility were included. 112 had a poor prognosis. Of those, 93 patients with a poor prognosis were included in the modified intention-to-treat analysis: 49 (53%) received SID and 44 (47%) received placebo. The adjusted common odds ratio for improvement on the Guillain-Barre syndrome disability score at 4 weeks was 1·4 (95% CI 0·6–3·3; p=0·45). Patients given SID had more serious adverse events (35% vs 16% in the first 30 days), including thromboembolic events, than those in the placebo group. Four patients died in the intervention group (13–24 weeks after randomisation). Interpretation Our study does not provide evidence that patients with Guillain-Barre syndrome with a poor prognosis benefit from a second intravenous immunoglobulin course; moreover, it entails a risk of serious adverse events. Therefore, a second intravenous immunoglobulin course should not be considered for treatment of Guillain-Barre syndrome because of a poor prognosis. The results indicate the need for treatment trials with other immune modulators in patients severely affected by Guillain-Barre syndrome. Funding Prinses Beatrix Spierfonds and Sanquin Plasma Products.

Inflammatory Rasch-built overall disability scale (I-RODS) seems to be a valid activity measure for use in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Our aim was to translate and validate the I-RODS for use in CIDP patients from Serbia. Study comprised 83 patients diagnosed with CIDP. I-RODS was translated and cross-culturally validated using the standard guidelines. Following scales were also administered: Medical Research Council (MRC) sum score, Inflammatory Neuropathy Cause and Treatment (INCAT) sensory and disability scores, Krupp's Fatigue Severity Scale, Beck Depression Inventory, Visual Analogue Scale for pain, and health survey-36 (SF-36) as a quality of life measure. According to the I-RODS, significant proportion of our patients reported that "running" (51%), "dancing" (41%), and "standing for hours" (40%) were impossible tasks to perform, while "teeth brushing" (94%), "eating" (88%), and "reading a newspaper/book" (82%) were noted as the easiest items. Patients with more muscle weakness (lower MRC sum score) and more severe INCAT sensory score had lower I-RODS score (P 1 (P

Introduction With increasing life expectancy, comorbidities become overt in Duchenne muscular dystrophy (DMD). Although micturition problems are common, bladder function is poorly understood in DMD. We studied dystrophin expression and multiple isoform involvement in the bladder during maturation to gain insights into their roles in micturition. Methods Dystrophin distribution was evaluated in rat bladders by immunohistochemical colocalization with smooth muscle, interstitial, urothelial, and neuronal markers. Protein levels of Dp140, Dp71, and smooth muscle were quantitated by Western blotting of neonatal to adult rat bladders. Results Dystrophin colocalized with smooth muscle cells and afferent nerve fibers. Dp71 was expressed two‐ to threefold higher compared with Dp140, independently of age. Age‐related muscle mass changes did not influence isoform expression levels. Discussion Dystrophin is expressed in smooth muscle cells and afferent nerve fibers in the urinary bladder, which underscores that micturition problems in DMD may have not solely a myogenic but also a neurogenic origin. Muscle Nerve 60: 202–210, 2019

In this retrospective study, we conducted a clinico-genetic analysis of patients with autosomal recessive limb-girdle muscular dystrophy (LGMD) and Miyoshi muscular dystrophy (MMD). Patients were identified at the tertiary referral centre for DNA diagnosis in the Netherlands and included if they carried two mutations in CAPN3, DYSF, SGCG, SGCA, SGCB, SGCD, TRIM32, FKRP or ANO5 gene. DNA was screened by direct sequencing and multiplex ligand-dependent probe amplification (MLPA) analysis. A total of 244 patients was identified; 68 LGMDR1/LGMD2A patients with CAPN3 mutations (28%), 67 sarcoglycanopathy patients (LGMDR3-5/LGMD2C-E) (27%), 64 LGMDR12/LGMD2L and MMD3 patients with ANO5 mutations (26%), 25 LGMDR2/LGMD2B and MMD1 with DYSF mutations (10%), 21 LGMDR9/LGMD2I with FKRP mutations (9%) and one LGMDR8/LGMD2H patient with TRIM32 mutations (

Attention-deficit hyperactivity disorder (ADHD) is a common comorbidity in Duchenne muscular dystrophy (DMD). Until now, treatment with methylphenidate (MPH) has never been systematically assessed and described in this population. Our aim was to evaluate the effectiveness and safety of short acting MPH for learning problems in males with DMD and ADHD. Neuropsychological (cognition and behavior) and medical data of a sample of ten males (mean age = 8.1 years, range 6.3-9.8) with DMD and an ADHD diagnosis was retrospectively analyzed at baseline (TO; without MPH), short-term follow-up (T1; with MPH; mean interval T0-T1 = 8.3 months, range 4.3-15.6), and long-term follow-up (T2; mean interval T1-T2 = 23.1 months, range 2.6-77.7). An initial MPH dose of 5 mg/day was given on school mornings, with an increase of 2.5-5 mg/week depending on individual tolerance and treatment response, until a sufficiently effective dose was reached (range 0.2-0.6 mg/kg/day). At T1, results demonstrated an improvement in attention (i.e. concentration, impulsivity, and distractibility) in four patients. Suboptimal effects were reported in four patients, and no effects in two patients. At T2, seven patients showed considerable improvement in attention. No major side effects were reported. Overall, our data show that short acting MPH can be clinically effective for learning problems in males with DMD and ADHD, with regular cardiac follow-up, and close monitoring of side effects and neuropsychological effects. Furthermore, this underscores the importance of the use of validated cognitive and behavioral measurement tools with adequate sensitivity to objectively evaluate the effect of MPH. (C) 2018 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

BackgroundNeuropathic pain is common in peripheral neuropathy. Recent genetic studies have linked pathogenic voltage-gated sodium channel (VGSC) variants to human pain disorders. Our aims are to determine the frequency of SCN9A, SCN10A and SCN11A variants in patients with pure small fibre neuropathy (SFN), analyse their clinical features and provide a rationale for genetic screening.MethodsBetween September 2009 and January 2017, 1139 patients diagnosed with pure SFN at our reference centre were screened for SCN9A, SCN10A and SCN11A variants. Pathogenicity of variants was classified according to established guidelines of the Association for Clinical Genetic Science and frequencies were determined. Patients with SFN were grouped according to the VGSC variants detected, and clinical features were compared.ResultsAmong 1139 patients with SFN, 132 (11.6%) patients harboured 73 different (potentially) pathogenic VGSC variants, of which 50 were novel and 22 were found in ≥ 1 patient. The frequency of (potentially) pathogenic variants was 5.1% (n=58/1139) for SCN9A, 3.7% (n=42/1139) for SCN10A and 2.9% (n=33/1139) for SCN11A. Only erythromelalgia-like symptoms and warmth-induced pain were significantly more common in patients harbouring VGSC variants.Conclusion(Potentially) pathogenic VGSC variants are present in 11.6% of patients with pure SFN. Therefore, genetic screening of SCN9A, SCN10A and SCN11A should be considered in patients with pure SFN, independently of clinical features or underlying conditions.

Contains fulltext : 235675.pdf (Publisher’s version ) (Open Access) Patient-relevant outcome measures for facioscapulohumeral muscular dystrophy (FSHD) are needed. The motor function measure (MFM) is an ordinal-based outcome measure for neuromuscular disorders, but its suitability to measure FSHD patients is questionable. Here, we performed Rasch analyses on MFM data from 194 FSHD patients to assess clinimetric properties in this patient group. Both the total scale and its three domains were analyzed (D1: standing position and transfers; D2: axial and proximal motor function; D3: distal motor function). Fit to the Rasch model, sample-item targeting, individual item fit, threshold ordering, sex- and age-based differential item functioning, response dependency and unidimensionality were assessed. Rasch analysis revealed multiple limitations of the MFM for FSHD, the most important being a large ceiling effect and suboptimal sample-item targeting, which were most pronounced for domains D2 and D3. There were disordered thresholds for most items, often resulting in items functioning in a dichotomous fashion. It was not possible to remodel the MFM into a Rasch-built interval scale. Remodeling of domain D1 into an interval scale with adequate fit statistics was achieved, but sample-item targeting remained suboptimal. Therefore, the MFM should be used with caution in FSHD patients, as it is not optimally suited to measure functional abilities in this patient group.

Objective The objective of this longitudinal, observational study was to investigate change over time in ability to perform activities of daily living in myotonic dystrophy type 1 (DM1). Methods Adults with genetically confirmed DM1 were recruited as part of the PhenoDM1 study in the UK. Data on activities of daily living were recorded through the DM1-ActivC at baseline and a follow-up visit after 12 (± 3) months. A subset of patients had advanced genetic testing to determine the size of the progenitor allele. Results Our sample comprised 150 patients with DM1 (mean age: 45 years; 52% female). Mean follow-up was 383 days. Mean DM1-ActivC total score at baseline was 71.24 (95% confidence interval 67.77–74.71) and at the follow-up visit 69.04 (65.54–72.54). Approximately 43% of patients had a lower score at the follow-up visit (indicating a decreased ability to perform activities of daily living), 24% a higher score (indicating an increased ability), and 33% the same score at baseline and follow-up. The mean annual change in the DM1-ActivC total score, estimated at − 2.06 (− 3.54 to − 0.59), was significantly related to patients’ baseline score, but not sex, disease duration, timed test results, or cytosine-thymine-guanine repeat length. Conclusions Change over time in ability to perform activities of daily living as recorded through the DM1-ActivC varies substantially between patients with DM1. Our data contribute to the understanding of the natural evolution of the disease, and should be helpful to inform the design of future trials based on the DM1-ActivC.

Measuring vibration perception threshold (VPT) accurately classifies and quantifies the severity of loss of vibration perception. A biothesiometer (Bio-thesiometer (R); Bio Medical Instrument Co, Ohio, USA) appears to be the most suitable tool to determine VPT due to its low inter-rater variability and low occurence of adaption to the sensation. Different VPT values for a biothesiometer have been described, however, specification on age, height and different measurement locations is currently lacking. The objective of our study was to identify determinants of vibration perception in non-diabetic subjects, in order to provide individualized normal values of VPTs for clinical practice. Measurements of the vibration perception were performed on the big toes, insteps, lateral malleoli, and wrists. A total of 205 healthy subjects were included (108 (52.7%) males) with a median [interquartile range] age of 59 [51;64] (range 21-80) years. Mean height was 174.45 +/- 9.20 cm and mean weight was 82.94 +/- 14.84 kg, resulting in a mean BMI of 27.19 +/- 4.00 kg/m(2). In stepwise forward linear regression analyses, age (st. beta = 0.51, p

PURPOSE. We hypothesized that longitudinal changes in corneal nerve morphology would differ between the central cornea and inferior whorl in relation to other measures of diabetic neuropathy.METHODS. Thirty patients with diabetes (age: 54.08 +/- 15.86, duration: 23.95 +/- 14.2, HbA1c: 7.51 +/- 1.37) and 19 age-matched healthy controls (age: 49.47 +/- 13.25) underwent assessment of neuropathy disability score (NDS), vibration perception threshold (VPT), cold (CPT) and warm (WPT) perception thresholds, peroneal motor nerve conduction velocity (PMNCV), corneal nerve fiber density (CNFD), branch density (CNBD), fiber length (CNFL), inferior whorl length (IWL), and the average of CNFL and IWL (ANFL) at baseline and after 1 to 8 years.RESULTS. In patients with diabetes, between baseline and follow-up, there was a significant reduction in CNBD (57.72 +/- 30.08 vs. 44.04 +/- 23.69; P = 0.02), CNFL (21.77 +/- 5.19 vs. 15.65 +/- 4.7; P CONCLUSIONS. There is evidence of corneal nerve loss in patients with diabetes, particularly at the inferior whorl during follow-up.

Neuropathic pain is believed to arise from damage to nociceptive C fibres in diabetic neuropathy (DN). We have utilised corneal confocal microscopy (CCM) to quantify the severity of small nerve fibre damage in relation to the severity of neuropathic pain and quality of life (QoL) in patients with and without painful DN. 30 controls and patients with painful (n = 78) and painless (n = 62) DN underwent assessment of large and small nerve fibre function, CCM, neuropathic symptoms (small fibre neuropathy symptom inventory questionnaire, neuropathic pain scale) and QoL (SF-36, pre-R-ODS and hospital anxiety and depression scale). Patients with painful compared to painless DN, had comparable neurophysiology and vibration perception, but lower corneal nerve fibre density (20.1 ± 0.87 vs. 24.13 ± 0.91, P = 0.005), branch density (44.4 ± 3.31 vs. 57.74 ± 3.98, P = 0.03), length (19.61 ± 0.81 vs. 22.77 ± 0.83, P = 0.01), inferior whorl length (18.03 ± 1.46 vs. 25.1 ± 1.95, P = 0.005) and cold sensation threshold (21.35 ± 0.99 vs. 26.08 ± 0.5, P

ObjectiveThis systematic review aims to provide an overview of instruments used to assess behavioral and psychosocial functioning of patients with Duchenne and Becker muscular dystrophy, as well as to review the psychometric properties and applicability of these instruments.MethodsFive databases (Embase, Psyc.info, ERIC, Pubmed/Medline, and Cochrane) were searched from inception to June, 2018. Potential articles were rated by two independent reviewers. A predefined PROSPERO form (CRD42017074518) was used to extract data from included articles.ResultsSixty-one instruments were used in 54 studies. The Child Behavior Checklist is commonly used, but it lacks disease specific psychometric information. Sixteen instruments that contained disease specific psychometric information were included for final evaluation. The results displayed three instruments that are potentially valid for screening of psychosocial problems: The Psychosocial Adjustment and Role Skills Scale 3rd edition, the Pediatric Quality of Life Inventory Generic module, and the Life Satisfaction Index for Adolescents with Duchenne muscular dystrophy. Appropriate instruments for screening of behavioral problems may be: the Strengths and Difficulties Questionnaire, the Generalized Anxiety Disorder-7 item questionnaire, and the Patient Health Questionnaire-9 item questionnaire.ConclusionsFurther research on psychometric properties of screening instruments is crucial to ascertain a gold standard for clinical and research purposes. Meanwhile, for definite diagnostics purposes we recommend a multimethod, multisource, multisetting assessment in this high-risk population.

Small-fiber neuropathy (SFN) patients experience a spectrum of sensory abnormalities, including attenuated responses to non-noxious temperatures in combination with a decreased density of the small-nerve fibers. Gain of-function mutations in the voltage-gated sodium channels SCN9A, SCN10A and SCN11A have been identified as an underlying genetic cause in a subpopulation of patients with SFN. Based on clinical-diagnostic tests for SFN, we have set up a panel of two read-outs reflecting SFN in zebrafish, being nerve density and behavioral responses. Nerve density was studied using a transgenic line in which the sensory neurons are GFP-labelled. For the behavioral experiments, a temperature-controlled water compartment was developed. This device allowed quantification of the behavioral response to temperature changes. By using these read-outs we demonstrated that zebrafish embryos transiently overexpressing the pathogenic human SCN9A p.(I228M) or p.(G856D) mutations both have a significantly decreased density of the small-nerve fibers. Additionally, larvae overexpressing the p. (I228M) mutation displayed a significant increase in activity induced by temperature change. As these features closely resemble the clinical hallmarks of SFN, our data suggest that transient overexpression of mutant human mRNA provides a model for SFN in zebrafish. This disease model may provide a basis for testing the pathogenicity of novel genetic variants identified in SFN patients. Furthermore, this model could be used for studying SFN pathophysiology in an in vivo model and for testing therapeutic interventions.

PATH study group., In patients with chronic inflammatory demyelinating polyneuropathy (CIDP), intravenous immunoglobulin (IVIG) is recommended to be periodically reduced to assess the need for ongoing therapy. However, little is known about the effectiveness of restabilization with IVIG in patients who worsen after IVIG withdrawal. In the Polyneuropathy And Treatment with Hizentra (PATH) study, the pre‐randomization period included sudden stopping of IVIG followed by 12 weeks of observation. Those deteriorating were then restabilized with IVIG. Of 245 subjects who stopped IVIG, 28 did not show signs of clinical deterioration within 12 weeks. Two hundred and seven received IVIG restabilization with an induction dose of 2 g/kg bodyweight (bw) IgPro10 (Privigen, CSL Behring, King of Prussia, Pennsylvania) and maintenance doses of 1 g/kg bw every 3 weeks for up to 13 weeks. Signs of clinical improvement were seen in almost all (n = 188; 91%) subjects. During IVIG restabilization, 35 subjects either did not show CIDP stability (n = 21, analyzed as n = 22 as an additional subject was randomized in error) or withdrew for other reasons (n = 14). Of the 22 subjects who did not achieve clinical stability, follow‐up information in 16 subjects after an additional 4 weeks was obtained. Nine subjects were reported to have improved, leaving a maximum of 27 subjects (13%) who either showed no signs of clinical improvement during the restabilization phase and 4 weeks post‐study or withdrew for other reasons. In conclusion, sudden IVIG withdrawal was effective in detecting ongoing immunoglobulin G dependency with a small risk for subjects not returning to their baseline 17 weeks after withdrawal., Editorial support was provided by Meridian HealthComms Ltd, funded by CSL Behring.

Itch is thought to represent the peculiar response to stimuli conveyed by somatosensory pathways shared with pain through the activation of specific neurons and receptors. It can occur in association with dermatological, systemic and neurological diseases, or be the side effect of certain drugs. However, some patients suffer from chronic idiopathic itch that is frequently ascribed to psychological distress and for which no biomarker is available to date. We investigated three multigenerational families, one of which diagnosed with joint hypermobility syndrome/Ehlers-Danlos syndrome hypermobility type (JHS/EDS-HT), characterized by idiopathic chronic itch with predominantly proximal distribution. Skin biopsy was performed in all eight affected members and revealed in six of them reduced intraepidermal nerve fibre density consistent with small fibre neuropathy. Whole exome sequencing identified two COL6A5 rare variants co-segregating with chronic itch in eight affected members and absent in non-affected members, and in one unrelated sporadic patient with type 1 painless diabetic neuropathy and chronic itch. Two families and the diabetic patient carried the nonsense c.6814G>T (p.Glu2272*) variant and another family carried the missense c.6486G>C (p.Arg2162Ser) variant. Both variants were predicted as likely pathogenic by in silico analyses. The two variants were rare (minor allele frequency < 0.1%) in 6271 healthy controls and absent in 77 small fibre neuropathy and 167 JHS/EDS-HT patients without itch. Null-allele test on cDNA from patients' fibroblasts of both families carrying the nonsense variant demonstrated functional haploinsufficiency due to activation of nonsense mediated RNA decay. Immunofluorescence microscopy and western blotting revealed marked disorganization and reduced COL6A5 synthesis, respectively. Indirect immunofluorescence showed reduced COL6A5 expression in the skin of patients carrying the nonsense variant. Treatment with gabapentinoids provided satisfactory itch relief in the patients carrying the mutations. Our findings first revealed an association between COL6A5 gene and familiar chronic itch, suggesting a new contributor to the pathogenesis of neuropathic itch and identifying a new candidate therapeutic target.

Small fiber neuropathy is a painful sensory nervous system disorder characterized by damage to unmyelinated C-and thinly myelinated A delta-nerve fibers, clinically manifested by burning pain in the distal extremities and dysautonomia. The clinical onset in adulthood suggests a time-dependent process. The mechanisms that underlie nerve fiber injury in small fiber neuropathy are incompletely understood, although roles for energetic stress have been suggested. In the present study, we report time-dependent degeneration of neurites from dorsal root ganglia neurons in culture expressing small fiber neuropathy-associated G856D mutant Nav1.7 channels and demonstrate a time-dependent increase in intracellular calcium levels [Ca2+](i) and reactive oxygen species, together with a decrease in ATP levels. Together with a previous clinical report of burning pain in the feet and hands associated with reduced levels of Na+/ K+-ATPase in humans with high altitude sickness, the present results link energetic stress and reactive oxygen species production with the development of a painful neuropathy that preferentially affects small-diameter axons.

Pain is a central feature in small fiber neuropathy (SFN), with only moderate effects of pharmacologic treatment. The evaluation of the efficacy of therapies on pain has been driven by static measures, and a circadian cycle has been suggested. The aim of this study is to evaluate the pain dynamics in SFN. A total of 165 patients completed a standardized pain diary 4 times per week over a 4-week period. Patients used the 11-point numeric rating scale for average diurnal, nocturnal, and maximum pain, taking into account the circumstances in which pain emerged most. Medication used, SFN-related complaints, sleep quality, and anatomic location of pain were also assessed. Neuropathic pain showed a length-dependent pattern. For pain intensity, marginal higher pain scores at night than during the day were shown, likely not clinically meaningful, with stable lower pain intensities in weekends compared with weekdays. The average pain intensity was stable during the 4 week period. Maximum pain was experienced mainly at rest and during sleep. Besides, pain intensity at night showed an inverse relationship with quality of sleep. In conclusion, for trials in SFN it is justified to use pain scores from any time of the day during short measurement periods.Perspective: This article presents for the first time the pain dynamics of SFN. The effect of pharmacologic treatment in SFN is often disappointing, partly owing to insufficient trial designs. The results of this study have added value in the development of new proper clinical trials in SFN. (C) 2018 by the American Pain Society

Few reliable data exist on the prevalence of skeletal muscle channelopathies. We determined the minimum point prevalence of genetically defined skeletal muscle channelopathies in the Netherlands and report their mutation spectrum. Minimum point prevalence rates were calculated as number of genetically-confirmed skeletal muscle channelopathy patients (CLCNJ, SCN4A, CACNAIS and KCNJ2 gene mutations) in the Netherlands (1990-2015) divided by the total number of at-risk individuals. Rates were expressed as cases/100.000 and 95% confidence intervals were calculated based on Poisson distribution. Results of standardized genetic diagnostic procedures were used to analyze mutation spectra. We identified 405 patients from 234 unrelated pedigrees, resulting in a minimum point prevalence of 2.38/100.000 (95% CI 2.16-2.63) for skeletal muscle channelopathies in the Netherlands. Minimum point prevalence rates for the disease groups, non-dystrophic myotonia and periodic paralysis, were 1.70/100.000 and 0.69/100.000 respectively. Sixty-one different CLCN1 mutations (including 12 novel mutations) were detected in myotonia congenita. Twenty-eight different SCN4A missense mutations (including three novel mutations) were identified in paramyotonia congenita/sodium channel myotonia, hypokalemic periodic paralysis and hyperkalemic periodic paralysis. Four different CACNAIS missense mutations were detected in hypokalemic periodic paralysis and five KCNJ2 missense mutations in Andersen Tawil syndrome. The minimum point prevalence rates for genetically-defined skeletal muscle channelopathies confirm their rare disease status in the Netherlands. Rates are almost twice as high as in the UK and more in line with pre-genetic prevalence estimates in parts of Scandinavia. Future diagnostic and therapeutic studies may benefit from knowledge of the mutation spectrum of skeletal muscle channelopathies. (C) 2018 Elsevier B.V. All rights reserved.

Background Pemetrexed is a folate analog inhibitor for the treatment of non–small-cell lung cancer (NSCLC) and malignant pleural mesothelioma. Folic acid and vitamin B12 supplementation before initiating pemetrexed is necessary because of high rates of cytopenias without supplementation. However, the timing of supplementation has not been thoroughly investigated. Patients and Methods This was a single-center, retrospective study investigating patients receiving pemetrexed from January 1, 2012, to June 30, 2015, who received same-day vitamin B12 supplementation versus ≥ 1 day before pemetrexed. The objective was to evaluate safety outcomes in patients who received vitamin B12 on the same day as pemetrexed (group A) versus vitamin B12 ≥ 1 day (group B) before pemetrexed. Results Two hundred eighty-one patients met the inclusion criteria: 137 patients in group A (same-day administration of vitamin B12) and 144 patients in group B (median time of vitamin B12 administration before pemetrexed, 7 days; range, 1-42 days). Mean changes in hematologic indices from cycle (C) 1 to C2 or C2 to C3 did not differ significantly between groups. There were no significant differences in clinical events between C1 and C2 or C2 and C3 requiring supportive care. There was a significant difference noted in treatment delay in C3 [28/114 (24.6%) group A vs. 14/118 (11.9%) group B, P = .0164]. In group A, significant predictors of delay in C3 were baseline hemoglobin (mean 13.3 g/dL vs. 12.4 g/dL, P = .0137) and ANC (mean 6 × 109/L vs. 5 × 109/L, P = .0003). Conclusion Same-day vitamin B12 and pemetrexed administration is a safe practice in NSCLC and malignant pleural mesothelioma patients.

We assessed whether a measure of more distal corneal nerve fibre loss at the inferior whorl(IW) region is better than proximal measures of central corneal nerve damage in relation to the diagnosis of diabetic peripheral neuropathy(DPN), painful DPN and quality of life(QoL). Participants underwent detailed assessment of neuropathy, QoL using the SF36 questionnaire, pain visual analogue score(VAS), and corneal confocal microscopy(CCM). Corneal nerve fibre density (CNFD), branch density (CNBD) and length (CNFL) at the central cornea and inferior whorl length (IWL) and average(ANFL) and total(TNFL) nerve fibre length were compared in patients with and without DPN and between patients with and without painful DPN and in relation to QoL. All CCM parameters were significantly reduced, but IWL was reduced ~three-fold greater than CNFL in patients with and without DPN compared to controls. IWL(p = 0.001), ANFL(p = 0.01) and TNFL(p = 0.02) were significantly lower in patients with painful compared to painless DPN. The VAS score correlated with IWL(r = −0.36, P = 0.004), ANFL(r = −0.32, P = 0.01) and TNFL(r = −0.32, P = 0.01) and QoL correlated with CNFL(r = 0.35, P = 0.01) and IWL(r = 0.4, P = 0.004). Corneal nerve fibre damage is more prominent at the IW, lower in patients with painful compared to painless neuropathy and relates to their QoL. IWL may provide additional clinical utility for CCM in patients with DPN.

Background and purpose Small fiber neuropathy (SFN) is a common disorder leading to neuropathic pain and autonomic symptoms. The objective of this study was to investigate associated conditions in a large cohort of SFN patients and compare the prevalence to healthy individuals. Methods A total of 921 patients with pure SFN were screened according to a standardized comprehensive diagnostic algorithm and compared with literature findings. Results No associated condition could be found in 53% of the patients. Autoimmune diseases, sodium channel gene mutations, diabetes mellitus including glucose intolerance, and vitamin B12 deficiencies were more prevalent than reported literature findings, followed by alcohol abuse, chemotherapy, monoclonal gammopathy of undetermined significance, and haemochromatosis. In patients who were already known with a possible underlying condition at screening, additional underlying conditions were still found in another 26.7% of patients. Conclusions Based on these results, it is recommended that patients with pure SFN are screened at least for autoimmune diseases, sodium channel gene mutations, diabetes mellitus including glucose intolerance, and vitamin B12 deficiency, even when they already have a potential underlying condition at referral.

OBJECTIVE Evidence from prospective studies for long-term treatment efficacy of spinal cord stimulation (SCS) in painful diabetic peripheral neuropathy (PDPN) is not available. We report prospective data on the effect of SCS on pain ratings, treatment success and failure, and complications during a 5-year follow-up in patients with PDPN. RESEARCH DESIGN AND METHODS Patients with PDPN (n = 48) were included in this prospective multicenter study. The Michigan Diabetic Neuropathy Score (MDNS) was used to assess the severity of neuropathy. Numerical rating scale (NRS) score for pain, Patient’s Global Impression of Change (PGIC), and treatment success (50% reduction of NRS score or significant PGIC) during 5 years of follow-up were evaluated. Complications of SCS were reported, and associations between baseline characteristics and SCS trial success or failure during a 5-year follow-up were investigated by using survival analyses. RESULTS Treatment success was observed in 55% of patients after 5 years. Median duration of SCS treatment was 60 months (minimum 1 month, maximum 60 months), and 80% of patients with a permanent implant still used their SCS device after 5 years. Higher MDNS was associated with treatment failure during the 5-year follow-up (hazard ratio 3.9 [95% CI 1.3–11.6]; P = 0.014). CONCLUSIONS SCS is successful in reducing chronic pain symptoms in the lower extremities of patients with PDPN up to 5 years after initiation of treatment. Furthermore, 80% of patients with PDPN still use their SCS device after 5 years. Moreover, the severity of neuropathy is associated with a higher chance of long-term treatment failure during a 5-year follow-up.

Mika Saarela työryhmän jäsenenä. Background Approximately two-thirds of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) need long-term intravenous immunoglobulin. Subcutaneous immunoglobulin (SCIg) is an alternative option for immunoglobulin delivery, but has not previously been investigated in a large trial of CIDP. The PATH study compared relapse rates in patients given SCIg versus placebo. Methods Between March 12, 2012, and Sept 20, 2016, we studied patients from 69 neuromuscular centres in North America, Europe, Israel, Australia, and Japan. Adults with definite or probable CIDP who responded to intravenous immunoglobulin treatment were eligible. We randomly allocated participants to 0.2 g/kg or 0.4 g/kg of a 20% SCIg solution (IgPro20) weekly versus placebo (2% human albumin solution) for maintenance treatment for 24 weeks. We did randomisation in a 1: 1:1 ratio with an interactive voice and web response system with a block size of six, stratified by region (Japan or non-Japan). The primary outcome was the proportion of patients with a CIDP relapse or who were withdrawn for any other reason during 24 weeks of treatment. Patients, caregivers, and study personnel, including those assessing outcomes, were masked to treatment assignment. Analyses were done in the intention-to-treat and per-protocol sets. This trial is registered with ClinicalTrials. gov, number NCT01545076. Findings In this randomised, double-blind, placebo-controlled trial, we randomly allocated 172 patients: 57 (33%) to the placebo group, 57 (33%) to the low-dose group, and 58 (34%) to the high-dose group. In the intention-to-treat set, 36 (63% [95% CI 50-74]) patients on placebo, 22 (39% [27-52]) on low-dose SCIg, and 19 (33% [22-46]) on high-dose SCIg had a relapse or were withdrawn from the study for other reasons (p=0.0007). Absolute risk reductions were 25% (95% CI 6-41) for low-dose versus placebo (p=0.007), 30% (12-46) for high-dose versus placebo (p=0.001), and 6% (-11 to 23) for high-dose versus low-dose (p=0.32). Causally related adverse events occurred in 47 (27%) patients (ten [18%] in the placebo group, 17 [30%] in the low-dose group, and 20 [34%] in the high-dose group). Six (3%) patients had 11 serious adverse events: one (2%) patient in the placebo group, three (5%) in the low-dose group, and two (3%) in the high-dose group; only one (an acute allergic skin reaction in the low-dose group) was assessed to be causally related. Interpretation This study, which is to our knowledge, the largest trial of CIDP to date and the first to study two administrations of immunoglobulins and two doses, showed that both doses of SCIg IgPro20 were efficacious and well tolerated, suggesting that SCIg can be used as a maintenance treatment for CIDP.

International audience; BACKGROUND: Fingolimod is approved for the treatment of relapsing-remitting multiple sclerosis and was effective in experimental autoimmune neuritis in rats, a possible model for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We aimed to evaluate the efficacy of fingolimod in delaying disability progression in patients with CIDP who withdrew from currently effective treatments (intravenous immunoglobulin [IVIg] or corticosteroids). METHODS: This double-blind, multicentre, randomised, placebo-controlled, parallel-group, event-driven study was done at 48 neurology centres in Australia, Canada, Israel, Japan, the USA, and nine countries in Europe. Participants with CIDP who were receiving IVIg or corticosteroids were randomly assigned (1:1) to once-daily oral fingolimod 0\textperiodcentered5 mg or placebo. Owing to the event-driven design, treatment duration was flexible and could be up to 4\textperiodcentered5 years. Randomisation was done with an automated interactive voice response-web response system and was stratified by Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale scores. Previous IVIg treatment was discontinued after one final course ending the day before the first dose of fingolimod or placebo was given, whereas corticosteroids were tapered off over 8 weeks after randomisation. The primary endpoint was time to first confirmed worsening (>=1 point increase on the adjusted INCAT disability scale score versus baseline) and was assessed in the full analysis set, which consisted of all patients who underwent randomisation and had at least one efficacy assessment for the primary analysis. The survival distribution functions of time to first worsening were estimated within each treatment group according to the Kaplan-Meier survival distribution function and compared with a stratified log-rank test. The trial is registered with ClinicalTrials.gov, number NCT01625182. FINDINGS: Of 106 participants randomly assigned between Jan 24, 2013, and March 10, 2016, 54 received fingolimod (41 who had been receiving IVIg and 13 who had been receiving corticosteroids) and 52 received placebo (41 who had been receiving IVIg and 11 who had been receiving corticosteroids). The trial ended for futility as recommended by an independent data monitoring committee after an interim analysis when 44 confirmed worsening events had occurred. At the end of the study, the survival estimate of the proportion of participants free from confirmed worsening was not significantly different between the fingolimod group (42%, 95% CI 23-60) and the placebo group (43%, 28-59; p=0\textperiodcentered91). Adverse events occurred in 41 (76%) participants receiving fingolimod and 44 (85%) on placebo, and serious adverse events occurred in nine (17%) and four (8%) patients, respectively. The most common adverse events with fingolimod were headache (12 [22%] patients), hypertension (ten [19%]), and extremity pain (seven [13%]). Adverse events leading to study discontinuation occurred in seven (13%) participants on fingolimod and none on placebo. INTERPRETATION: Fingolimod 0\textperiodcentered5 mg once-daily was not better than placebo for the treatment of CIDP. Future trial designs should take account of the possibility that if IVIg is stopped abruptly, some patients might relapse soon afterwards whereas others might remain in remission. FUNDING: Novartis Pharma.

Background: \ud Myotonic dystrophy type 1 is the most common form of muscular dystrophy in adults and leads to severe fatigue, substantial physical functional impairment, and restricted social participation. In this study, we aimed to determine whether cognitive behavioural therapy optionally combined with graded exercise compared with standard care alone improved the health status of patients with myotonic dystrophy type 1.\ud \ud Methods: \ud We did a multicentre, single-blind, randomised trial, at four neuromuscular referral centres with experience in treating patients with myotonic dystrophy type 1 located in Paris (France), Munich (Germany), Nijmegen (Netherlands), and Newcastle (UK). Eligible participants were patients aged 18 years and older with a confirmed genetic diagnosis of myotonic dystrophy type 1, who were severely fatigued (ie, a score of ≥35 on the checklist-individual strength, subscale fatigue). We randomly assigned participants (1:1) to either cognitive behavioural therapy plus standard care and optional graded exercise or standard care alone. Randomisation was done via a central web-based system, stratified by study site. Cognitive behavioural therapy focused on addressing reduced patient initiative, increasing physical activity, optimising social interaction, regulating sleep–wake patterns, coping with pain, and addressing beliefs about fatigue and myotonic dystrophy type 1. Cognitive behavioural therapy was delivered over a 10-month period in 10–14 sessions. A graded exercise module could be added to cognitive behavioural therapy in Nijmegen and Newcastle. The primary outcome was the 10-month change from baseline in scores on the DM1-Activ-c scale, a measure of capacity for activity and social participation (score range 0–100). Statistical analysis of the primary outcome included all participants for whom data were available, using mixed-effects linear regression models with baseline scores as a covariate. Safety data were presented as descriptives. This trial is registered with ClinicalTrials.gov, number NCT02118779.\ud \ud Findings: \ud Between April 2, 2014, and May 29, 2015, we randomly assigned 255 patients to treatment: 128 to cognitive behavioural therapy plus standard care and 127 to standard care alone. 33 (26%) of 128 assigned to cognitive behavioural therapy also received the graded exercise module. Follow-up continued until Oct 17, 2016. The DM1-Activ-c score increased from a mean (SD) of 61·22 (17·35) points at baseline to 63·92 (17·41) at month 10 in the cognitive behavioural therapy group (adjusted mean difference 1·53, 95% CI −0·14 to 3·20), and decreased from 63·00 (17·35) to 60·79 (18·49) in the standard care group (−2·02, −4·02 to −0·01), with a mean difference between groups of 3·27 points (95% CI 0·93 to 5·62, p=0·007). 244 adverse events occurred in 65 (51%) patients in the cognitive behavioural therapy group and 155 in 63 (50%) patients in the standard care alone group, the most common of which were falls (155 events in 40 [31%] patients in the cognitive behavioural therapy group and 71 in 33 [26%] patients in the standard care alone group). 24 serious adverse events were recorded in 19 (15%) patients in the cognitive behavioural therapy group and 23 in 15 (12%) patients in the standard care alone group, the most common of which were gastrointestinal and cardiac.\ud \ud Interpretation: \ud Cognitive behavioural therapy increased the capacity for activity and social participation in patients with myotonic dystrophy type 1 at 10 months. With no curative treatment and few symptomatic treatments, cognitive behavioural therapy could be considered for use in severely fatigued patients with myotonic dystrophy type 1.\ud \ud Funding: \ud The European Union Seventh Framework Programme.

Background. Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side effect of oxaliplatin which can negatively influence quality of life. We aimed to study the influence of cumulative dose, dose schedule and dose reductions of adjuvant oxaliplatin on long-term severity and prevalence of CIPN among colorectal cancer (CRC) survivors.Material and methods. In total 207 patients, diagnosed with CRC between 2000 and 2009 who underwent adjuvant treatment with oxaliplatin, were included. They completed the EORTC QLQ-CIPN20 2–11 years after diagnosis. Data on oxaliplatin administration and acute neuropathy during treatment were extracted from the medical files. Subscales were analyzed with analysis of covariance and neuropathy symptoms with logistic regression analysis.Results. Patients who received cumulative oxaliplatin dose of ≥ 842 mg/m2 had a significantly worse EORTC QLQ-CIPN20 sensory score compared to those who received a low cumulative dose of < 421 mg/m2 (mean 19 vs. 8; p = 0.02). They more often reported tingling toes/feet (13% vs. 2%, respectively; p = 0.01). Dose intensity and time delay did not influence the occurrence of CIPN. Patients receiving a dose reduction because of neuropathy (N = 50) reported a significantly worse sensory score at very similar cumulative doses, than those who did not receive a dose reduction because of neuropathy (N = 96) (mean 21 vs. 15; p = 0.01).Conclusion. Cumulative dose of oxaliplatin is associated with long-term CIPN. The risk of developing long-term CIPN could only be reduced by decreasing the cumulative dose, whereas delay probably is not beneficial. Patients receiving a dose reduction because of acute neuropathy are still at risk of developing long-term CIPN. Future studies should focus on identifying patients who are at risk of developing CIPN.

Objectives: We performed responsiveness comparison between the patient-reported Inflammatory Rasch-built Overall Disability Scale (I-RODS) and the widely used clinician-reported Inflammatory Neuropathy Cause and Treatment-Overall Neuropathy Limitation Scale (INCAT-ONLS) in patients with Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and immunoglobulin M-monoclonal gammopathy of undetermined significance related polyneuropathy (IgM-MGUSP). Methods: One hundred thirty-seven patients (GBS: 55, CIDP: 59, IgM-MGUSP: 23) with a new diagnosis or clinical relapse assessed both scales. Patients with GBS/CIDP were examined at 0, 1, 3, 6, and 12 months; patients with IgM-MGUSP at 0, 3, and 12. We subjected all data to Rasch analyses, and calculated for each patient the magnitude of change on both scales using the minimal clinically important difference (MCID) related to the individual standard errors (SEs). A responder was defined as having anMCID-SE >= 1.96. Individual scores on both measures were correlated with the EuroQoL thermometer (heuristic responsiveness). Results: The I-RODS showed a significantly higher proportion of meaningful improvement compared with the INCAT-ONLS findings in GBS/CIDP. For IgM-MGUSP, the lack of responsiveness during the 1-year study did not allow a clear separation. Heuristic responsiveness was consistently higher with the I-RODS. Conclusion: The I-RODS more often captures clinically meaningful changes over time, with a greater magnitude of change, compared with the INCAT-ONLS disability scale in patients with GBS and CIDP. The I-RODS offers promise for being a more sensitive measure and its use is therefore suggested in future trials involving patients with GBS and CIDP.

Summary Objective Statistical shape modelling (SSM) of radiographs has been used to explore relationships between altered joint shape and hip osteoarthritis (OA). We aimed to apply SSM to Dual-energy X-ray Absorptiometry (DXA) hip scans, and examine associations between resultant hip shape modes (HSMs), radiographic hip OA (RHOA), and hip pain, in a large population based cohort. Method SSM was performed on baseline hip DXA scans from the Osteoporotic Fractures in Men (MrOS) Study. Associations between the top ten HSMs, and prevalent RHOA from pelvic radiographs obtained 4.6 years later, were analysed in 4100 participants. RHOA was defined as Croft score ≥2. Hip pain was based on pain on walking, hip pain on examination, and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Results The five HSMs associated with RHOA showed features of either pincer- or cam-type deformities. HSM 1 (increased pincer-type deformity) was positively associated with RHOA [1.23 (1.09, 1.39)] [odds ratio (OR) and 95% CI]. HSM 8 (reduced pincer-type deformity) was inversely associated with RHOA [0.79 (0.70, 0.89)]. HSM 10 (increased cam-type deformity) was positively associated with RHOA [1.21 (1.07, 1.37)]. HSM 3 and HSM 4 (reduced cam-type deformity) were inversely associated with RHOA [0.73 (0.65, 0.83) and 0.82 (0.73, 0.93), respectively]. HSM 3 was inversely related to pain on examination [0.84 (0.76, 0.92)] and walking [0.88, (0.81, 0.95)], and to WOMAC score [0.87 (0.80, 0.93)]. Conclusions DXA-derived measures of hip shape are associated with RHOA, and to a lesser extent hip pain, possibly reflecting their role in the pathogenesis of hip OA.

The objective was to perform an economic evaluation comparing spinal cord stimulation (SCS) in combination with best medical treatment (BMT) with BMT in painful diabetic peripheral neuropathy patients. Alongside a prospective 2-center randomized controlled trial, involving 36 painful diabetic peripheral neuropathy patients with severe lower limb pain not responding to conventional therapy, an economic evaluation was performed. Incremental cost-effectiveness ratios were based on: 1) societal costs and quality-adjusted life years (QALYs), and 2) direct health care costs and the number of successfully treated patients, respectively, both with a time horizon of 12 months. Bootstrap and secondary analyses were performed to address uncertainty. Total societal cost amounted to (sic)26,539.18 versus (sic)5,313.45 per patient in the SCS and BMT group, respectively. QALYs were .58 versus .36 and the number of successfully treated patients was 55% versus 7% for the SCS and BMT group, respectively. This resulted in incremental cost-effectiveness ratios of (sic)94,159.56 per QALY and (sic)34,518.85 per successfully treated patient, respectively. Bootstrap analyses showed that the probability of SCS being cost-effective ranges from 0 to 46% with willingness to pay threshold values ranging between (sic)20,000 and (sic)80,000 for a QALY. Secondary analyses showed that cost-effectiveness of SCS became more favorable after correcting for baseline cost imbalance between the 2 groups, extending the depreciation period of SCS material to 4 years, and extrapolation of the data up to 4 years. Although SCS was considerably more effective compared with BMT, the substantial initial investment that is required resulted in SCS not being cost-effective in the short term. Cost-effectiveness results were sensitive to baseline cost imbalances between the groups and the depreciation period of the SCS material.Perspective: Painful diabetic peripheral neuropathy is a common complication of diabetes mellitus and the humanistic and economic burden is high. This article presents the cost-effectiveness of SCS in patients suffering from painful diabetic peripheral neuropathy from a societal and health care perspective with a time horizon of 12 months. (C) 2016 by the American Pain Society

The aetiology of painful peripheral neuropathy is often unknown. Huang et al. sequence the gene encoding sodium channel Na(v)1.9 in 393 patients with small fibre neuropathy and identify eight variants in 12 individuals. Functional analysis of two variants reveals that they confer gain-of-function attributes to Na(v)1.9, and induce nociceptor hyperexcitability.Sodium channel Na(v)1.9 is expressed in peripheral nociceptive neurons, as well as visceral afferents, and has been shown to act as a threshold channel. Painful peripheral neuropathy represents a significant public health challenge and may involve gain-of-function variants in sodium channels that are preferentially expressed in peripheral sensory neurons. Although gain-of-function variants of peripheral sodium channels Na(v)1.7 and Na(v)1.8 have recently been found in painful small fibre neuropathy, the aetiology of peripheral neuropathy in many cases remains unknown. We evaluated 459 patients who were referred for possible painful peripheral neuropathy, and confirmed the diagnosis of small fibre neuropathy in a cohort of 393 patients (369 patients with pure small fibre neuropathy, and small fibre neuropathy together with large fibre involvement in an additional 24 patients). From this cohort of 393 patients with peripheral neuropathy, we sequenced SCN11A in 345 patients without mutations in SCN9A and SCN10A, and found eight variants in 12 patients. Functional profiling by electrophysiological recordings showed that these Na(v)1.9 mutations confer gain-of-function attributes to the channel, depolarize resting membrane potential of dorsal root ganglion neurons, enhance spontaneous firing, and increase evoked firing of these neurons. Our data show, for the first time, missense mutations of Na(v)1.9 in individuals with painful peripheral neuropathy. These genetic and functional observations identify missense mutations of Na(v)1.9 as a cause of painful peripheral neuropathy.

OBJECTIVE Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus. Unfortunately, pharmacological treatment is often partially effective or accompanied by unacceptable side effects, and new treatments are urgently needed. Small observational studies suggested that spinal cord stimulation (SCS) may have positive effects. RESEARCH DESIGN AND METHODS We performed a multicenter randomized clinical trial in 36 PDPN patients with severe lower limb pain not responding to conventional therapy. Twenty-two patients were randomly assigned to SCS in combination with the best medical treatment (BMT) (SCS group) and 14 to BMT only (BMT group). The SCS system was implanted only if trial stimulation was successful. Treatment success was defined as ≥50% pain relief during daytime or nighttime or “(very) much improved” for pain and sleep on the patient global impression of change (PGIC) scale at 6 months. RESULTS Trial stimulation was successful in 77% of the SCS patients. Treatment success was observed in 59% of the SCS and in 7% of the BMT patients (P < 0.01). Pain relief during daytime and during nighttime was reported by 41 and 36% in the SCS group and 0 and 7% in the BMT group, respectively (P < 0.05). Pain and sleep were “(very) much improved” in 55 and 36% in the SCS group, whereas no changes were seen in the BMT group, respectively (P < 0.001 and P < 0.05). One SCS patient died because of a subdural hematoma. CONCLUSIONS Treatment success was shown in 59% of patients with PDPN who were treated with SCS over a 6-month period, although this treatment is not without risks.

This study describes the swallowing function of patients with myotonic dystrophy type 1 (DM1) and the effect of bolus consistency on swallowing in this group. The aim of the study is twofold: (a) to identify which (and to what extent) swallowing variables change for DM1 patients relative to healthy control subjects and (b) to examine whether the degree of oropharyngeal dysphagia is associated with disease severity. Forty-five consecutive DM1 patients and ten healthy subjects underwent a swallowing assessment, at Maastricht University medical Center in the Netherlands. The assessment included a standardized fiberoptic endoscopic evaluation of swallowing (FEES) protocol using different bolus consistencies. Clinical severity of the disease was assessed using the muscular impairment rating scale (MIRS). Significant differences were found between patients and controls for all FEES variables. The magnitude of these differences depended on the bolus consistency. The odds of a more pathological swallowing outcome increased significantly with higher MIRS levels. In conclusion, swallowing function is found to be significantly altered in DM1 patients. The results emphasize the importance of conducting a detailed swallowing assessment in all patients, even those with mild muscle weakness. (C) 2014 Elsevier B.V. All rights reserved.

Objective: To determine the minimum incidence and minimum prevalence rates of small-fiber neuropathy (SFN) in a well-defined region in the southern part of the Netherlands. Methods: In this cross-sectional study with retrospective data collection, we used data of patients diagnosed with pure SFN at our Small Fiber Neuropathy Center between January 2006 and December 2011 to calculate minimum incidence and prevalence rates. Results: A total of 88 patients were diagnosed with SFN (mean age 56.9 years, SD 11.8, range 34–81; 44.3% women, 55.7% men). The overall minimum incidence over 2010 and 2011 was 11.73 (95% confidence interval 7.12–18.22) cases/100,000 inhabitants/year. The overall minimum prevalence was 52.95 (95% confidence interval 42.47–65.23) cases/100,000. Incidence and prevalence rates were higher in men than in women, as were the rates in elderly patients compared with younger patients. Conclusions: The minimum incidence and prevalence rates of SFN are presented. We found that SFN is more frequently seen in men and more often diagnosed in elderly patients. These rates probably are an underestimation and are expected to increase in the coming years, since the awareness of SFN is increasing worldwide.

Idiopathic small-fiber neuropathy (I-SFN), clinically characterized by burning pain in distal extremities and autonomic dysfunction, is a disorder of small-caliber nerve fibers of unknown etiology with limited treatment options. Functional variants of voltage-gated sodium channel Na(v)1.7, encoded by SCN9A, have been identified in approximately one-third of I-SFN patients. These variants render dorsal root ganglion (DRG) neurons hyperexcitable. Sodium channel Na(v)1.8, encoded by SCN10A, is preferentially expressed in small-diameter DRG neurons, and produces most of the current underlying the upstroke of action potentials in these neurons. We previously demonstrated two functional variants of Na(v)1.8 that either enhance ramp current or shift activation in a hyperpolarizing direction, and render DRG neurons hyperexcitable, in I-SFN patients with no mutations of SCN9A. We have now evaluated additional I-SFN patients with no mutations in SCN9A, and report a novel I-SFN-related Na(v)1.8 mutation I1706V in a patient with painful I-SFN. Whole-cell voltage-clamp recordings in small DRG neurons demonstrate that the mutation hyperpolarizes activation and the response to slow ramp depolarizations. However, it decreases fractional channels resistant to fast inactivation and reduces persistent currents. Current-clamp studies reveal that mutant channels decrease current threshold and increase the firing frequency of evoked action potentials within small DRG neurons. These observations suggest that the effects of this mutation on activation and ramp current are dominant over the reduced persistent current, and show that these pro-excitatory gating changes confer hyperexcitability on peripheral sensory neurons, which may contribute to pain in this individual with I-SFN.

Congenital myasthenic syndromes are a clinically and genetically heterogeneous group of hereditary disorders affecting neuromuscular transmission. We have identified mutations within the acetylcholine receptor (AChR) ε-subunit gene underlying congenital myasthenic syndromes in nine patients (seven kinships) of Dutch origin. Previously reported mutations ε1369delG and εR311Q were found to be common; ε1369delG was present on at least one allele in seven of the nine patients, and εR311Q in six. Phenotypes ranged from relatively mild ptosis and external ophthalmoplegia to generalized myasthenia. The common occurrence of εR311Q and ε1369delG suggests a possible founder for each of these mutations originating in North Western Europe, possibly in Holland. Knowledge of the ethnic or geographic origin within Europe of AChR deficiency patients can help in targeting genetic screening and it may be possible to provide a rapid genetic diagnosis for patients of Dutch origin by screening first for εR311Q and ε1369delG. Electronic supplementary material The online version of this article (doi:10.1007/s00415-009-5190-7) contains supplementary material, which is available to authorized users.

Background Small fiber neuropathy generally leads to considerable pain and autonomic symptoms. Gain-of-function mutations in the SCN9A- gene, which codes for the Nav1.7 voltage-gated sodium channel, have been reported in small fiber neuropathy, suggesting an underlying genetic basis in a subset of patients. Currently available sodium channel blockers lack selectivity, leading to cardiac and central nervous system side effects. Lacosamide is an anticonvulsant, which blocks Nav1.3, Nav1.7, and Nav1.8, and stabilizes channels in the slow-inactivation state. Since multiple Nav1.7 mutations in small fiber neuropathy showed impaired slow-inactivation, lacosamide might be effective. Methods/design The Lacosamide-Efficacy-‘N’-Safety in Small fiber neuropathy (LENSS) study is a randomized, double-blind, placebo-controlled, crossover trial in patients with SCN9A-associated small fiber neuropathy, with the primary objective to evaluate the efficacy of lacosamide versus placebo. Eligible patients (the aim is to recruit 25) fulfilling the inclusion and exclusion criteria will be randomized to receive lacosamide (200 mg b.i.d.) or placebo during the first double-blinded treatment period (8 weeks), which is preceded by a titration period (3 weeks). The first treatment period will be followed by a tapering period (2 weeks). After a 2-week washout period, patients will crossover to the alternate arm for the second period consisting of an equal titration phase, treatment period, and tapering period. The primary efficacy endpoint will be the proportion of patients demonstrating a 1-point average pain score reduction compared to baseline using the Pain Intensity Numerical Rating Scale. We assume a response rate of approximately 60 % based on the criteria composed by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) group for measurement of pain. Patients withdrawing from the study will be considered non- responders. Secondary outcomes will include changes in maximum pain score, the Small Fiber Neuropathy Symptoms Inventory Questionnaire, sleep quality and the quality of life assessment, patients’ global impressions of change, and safety and tolerability measurements. Sensitivity analyses will include assessing the proportion of patients having ≥ 2 points average pain improvement compared to the baseline Pain Intensity Numerical Rating Scale scores. Discussion This is the first study that will be evaluating the efficacy, safety, and tolerability of lacosamide versus placebo in patients with SCN9A-associated small fiber neuropathy. The findings may increase the knowledge on lacosamide as a potential treatment option in patients with painful neuropathies, considering the central role of Nav1.7 in pain. Trial registration ClinicalTrials.gov, NCT01911975. Registered on 13 July 2013. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1430-1) contains supplementary material, which is available to authorized users.

Objective Screening for Fabry disease in patients with small fiber neuropathy has been suggested, especially since Fabry disease is potentially treatable. However, the diagnostic yield of testing for Fabry disease in isolated small fiber neuropathy patients has never been systematically investigated. Our aim is to determine the presence of Fabry disease in patients with small fiber neuropathy. Methods Patients referred to our institute, who met the criteria for isolated small fiber neuropathy were tested for Fabry disease by measurement of alpha-Galactosidase A activity in blood, lysosomal globotriaosylsphingosine in urine and analysis on possible GLA gene mutations. Results 725 patients diagnosed with small fiber neuropathy were screened for Fabry disease. No skin abnormalities were seen except for redness of the hands or feet in 30.9% of the patients. Alfa-Galactosidase A activity was tested in all 725 patients and showed diminished activity in eight patients. Lysosomal globotriaosylsphingosine was examined in 509 patients and was normal in all tested individuals. Screening of GLA for mutations was performed for 440 patients, including those with diminished α-Galactosidase A activity. Thirteen patients showed a GLA gene variant. One likely pathogenic variant was found in a female patient. The diagnosis Fabry disease could not be confirmed over time in this patient. Eventually none of the patients were diagnosed with Fabry disease. Conclusions In patients with isolated small fiber neuropathy, and no other signs compatible with Fabry disease, the diagnostic yield of testing for Fabry disease is extremely low. Testing for Fabry disease should be considered only in cases with additional characteristics, such as childhood onset, cardiovascular disease, renal failure, or typical skin lesions.

Item does not contain fulltext BACKGROUND AND PURPOSE: There is increasing interest in using patient-reported outcome measures (PROMs) in clinical studies to capture individual changes over time. However, PROMs have also been criticized because they are entirely subjective. Our objective was to examine the relationship between a subjective PROM and an objective outcome tool in patients with Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and gammopathy-related polyneuropathy (MGUSP). METHODS: The Inflammatory Rasch-built Overall Disability Scale (I-RODS(c), a multi-item scale that examines functionality) was completed by 137 patients with newly diagnosed (or relapsing) GBS (55), CIDP (59) and MGUSP (23) who were serially examined (GBS/CIDP, T0/T1/T3/T6/T12 months; MGUSP, T0/T3/T12). Possible association between the I-RODS findings and the vigorimeter scores, an objective linear instrument to assess grip strength, was examined. RESULTS: A significant correlating trend was found between the I-RODS and grip strength scores for the overall group and in each illness, independently. CONCLUSION: The objectivity of patients' subjective report on their functional state based on a strong correlation between the I-RODS and grip strength in patients with GBS, CIDP and MGUSP has been demonstrated. These findings provide further support to use the I-RODS and grip strength in future clinical studies in these conditions.

Based on approximately eight years of data collection with the nationwide Computer Registry of All Myopathies and Polyneuropathies (CRAMP) in the Netherlands, recent epidemiologic information for thirty neuromuscular disorders is presented. This overview includes age and gender data for a number of neuromuscular disorders that are either relatively frequently seen in the neuromuscular clinic, or have a particular phenotype. Since 2004, over 20,000 individuals with a neuromuscular disorder were registered in CRAMP; 56% men and 44% women. The number per diagnosis varied from nine persons with Emery Dreifuss muscular dystrophy to 2057 persons with amyotrophic lateral sclerosis. Proportions of men ranged from 38% with post-polio syndrome to 68% with progressive spinal muscular atrophy, excluding X-chromosome linked disorders. Inclusion body myositis showed the highest median age at diagnosis of 70 years. These data may be helpful in the diagnostic process in clinical practice and trial readiness. (C) 2016 Elsevier B.V. All rights reserved.

Background Painful diabetic polyneuropathy (PDP) is associated with high pain scores and is difficult to treat. Therefore, spinal cord stimulation (SCS) has been suggested as second-line treatment. In this study, the feasibility and efficacy of SCS in PDP were investigated, as well as the predictive value of clinical sensory testing for the treatment outcome. Methods Fifteen patients with intractable PDP in the lower limbs were recruited. During lead implantation, the feasibility of achieving adequate paraesthesia coverage using one stimulation lead was investigated. If trial stimulation was successful, a definitive neurostimulator was implanted. Pain intensity was scored using an 11-point numeric rating scale and patients' global impression of change scale. Additionally, neuropathic pain characteristics, quality of life, sleep quality and mood were assessed. The predictive value of clinical sensory testing for the treatment outcome was analysed. Results Adequate paraesthesia coverage was achieved in 14 out of 15 patients. Clinically relevant pain relief was present in 11 patients after trial stimulation and 10 patients at 12 months. The quality of life was significantly increased at 2 weeks and 3 months in patients with successful SCS treatment. Several neuropathic pain characteristics and quality of sleep were improved at 2 weeks and 12 months. Preoperative clinical sensory testing did not differentiate between treatment responders from non-responders. Conclusions SCS seems to be an efficacious and feasible treatment for intractable PDP. In this exploratory study, it was not possible to predict the treatment outcome using clinical sensory testing. These results justify performing a randomized clinical trial.

Item does not contain fulltext Patients with small fibre neuropathy typically manifest pain in distal extremities and severe autonomic dysfunction. However, occasionally patients present with minimal autonomic symptoms. The basis for this phenotypic difference is not understood. Sodium channel Na(v)1.7, encoded by the SCN9A gene, is preferentially expressed in the peripheral nervous system within sensory dorsal root ganglion and sympathetic ganglion neurons and their small diameter peripheral axons. We recently reported missense substitutions in SCN9A that encode functional Na(v)1.7 variants in 28% of patients with biopsy-confirmed small fibre neuropathy. Two patients with biopsy-confirmed small fibre neuropathy manifested minimal autonomic dysfunction unlike the other six patients in this series, and both of these patients carry the Na(v)1.7/R185H variant, presenting the opportunity to compare variants associated with extreme ends of a spectrum from minimal to severe autonomic dysfunction. Herein, we show by voltage-clamp that R185H variant channels enhance resurgent currents within dorsal root ganglion neurons and show by current-clamp that R185H renders dorsal root ganglion neurons hyperexcitable. We also show that in contrast, R185H variant channels do not produce detectable changes when studied by voltage-clamp within sympathetic neurons of the superior cervical ganglion, and have no effect on the excitability of these cells. As a comparator, we studied the Na(v)1.7 variant I739V, identified in three patients with small fibre neuropathy characterized by severe autonomic dysfunction as well as neuropathic pain, and show that this variant impairs channel slow inactivation within both dorsal root ganglion and superior cervical ganglion neurons, and renders dorsal root ganglion neurons hyperexcitable and superior cervical ganglion neurons hypoexcitable. Thus, we show that R185H, from patients with minimal autonomic dysfunction, does not produce detectable changes in the properties of sympathetic ganglion neurons, while I739V, from patients with severe autonomic dysfunction, has a profound effect on excitability of sympathetic ganglion neurons.

Cannabis use has been found to increase the risk of psychosis. It is unclear whether, after a first psychotic episode has occurred, continued cannabis use is associated with poor functional outcome of psychosis.As part of a randomized, open-label, controlled trial, the association of cannabis use and measures for psychopathology and social role functioning after 2 years of follow-up and for the recently proposed outcome measures of symptomatic remission, functional remission, and clinical recovery was explored in a group of 124 patients suffering from nonaffective first-episode psychosis (diagnosed according to DSM-IV and included from a catchment area in the Netherlands of 3.1 million inhabitants from October 2001 through December 2002). Other patient characteristics that were expected to be independently associated with outcome, among them alcohol and other drug use, were assessed at baseline.Continued cannabis use was not associated with symptomatic or functional remission or clinical recovery. After 2 years, cannabis use was related to certain aspects of social role functioning (economic and social activities; explained variance 5.6% and 8.4%, respectively) but not to psychopathology (Positive and Negative Syndrome Scale Positive, Negative, or General symptoms).Our findings support the notion that continued cannabis use after the onset of a first-episode psychosis is correlated with worse social outcome and should be discouraged whenever possible, but its role in outcome is modest in comparison to other factors.Nederlands Trial Register: http://www.trialregister.nl (ID: NTR 374).

Item does not contain fulltext OBJECTIVE: Small nerve fiber neuropathy (SFN) often occurs without apparent cause, but no systematic genetic studies have been performed in patients with idiopathic SFN (I-SFN). We sought to identify a genetic basis for I-SFN by screening patients with biopsy-confirmed idiopathic SFN for mutations in the SCN9A gene, encoding voltage-gated sodium channel Na(V)1.7, which is preferentially expressed in small diameter peripheral axons. METHODS: Patients referred with possible I-SFN, who met the criteria of >/=2 SFN-related symptoms, normal strength, tendon reflexes, vibration sense, and nerve conduction studies, and reduced intraepidermal nerve fiber density (IENFD) plus abnormal quantitative sensory testing (QST) and no underlying etiology for SFN, were assessed clinically and by screening of SCN9A for mutations and functional analyses. RESULTS: Twenty-eight patients who met stringent criteria for I-SFN including abnormal IENFD and QST underwent SCN9A gene analyses. Of these 28 patients with biopsy-confirmed I-SFN, 8 were found to carry novel mutations in SCN9A. Functional analysis revealed multiple gain of function changes in the mutant channels; each of the mutations rendered dorsal root ganglion neurons hyperexcitable. INTERPRETATION: We show for the first time that gain of function mutations in sodium channel Na(V)1.7, which render dorsal root ganglion neurons hyperexcitable, are present in a substantial proportion (28.6%; 8 of 28) of patients meeting strict criteria for I-SFN. These results point to a broader role of Na(V)1.7 mutations in neurological disease than previously considered from studies on rare genetic syndromes, and suggest an etiological basis for I-SFN, whereby expression of gain of function mutant sodium channels in small diameter peripheral axons may cause these fibers to degenerate. 01 januari 2012