Electro-clinical presentation of hereditary transthyretin related amyloidosis when presenting as a polyneuropathy of unknown origin in northern France.

INTRODUCTION: Hereditary transthyretin related amyloidosis (h-ATTR) classically presents as a small fiber neuropathy with positive family history, but can also be revealed by various other types of peripheral neuropathy. OBJECTIVE: To describe the initial electro-clinical presentation of patients from in a single region (northern France) of h-ATTR when it presents as a polyneuropathy of unknown origin. METHOD: We reviewed the records of patients referred to two neuromuscular centers from northern France with a peripheral neuropathy of unknown origin who were subsequently diagnosed with h-ATTR. RESULTS: Among 26 h-ATTR patients (10 Val30Met, 16 Ser77Tyr), only 14 patients had a suspicious family history (53.8%). The electro-clinical presentation was mostly a large-fiber sensory motor polyneuropathy (92.3%), which could be symmetric or not, length-dependent or not, or associated with nerve entrapment or not. Demyelinating signs were observed in 17 patients (70.8%), among whom nine fulfilled the criteria for a definite diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (37.5%). CONCLUSION: h-ATTR may have a wide spectrum of clinical profiles, and should be considered in the screening of polyneuropathies of unknown origin.

Intravenous immunoglobulin for treatment of chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy in France: are daily practices in accordance with guidelines?

BACKGROUND AND PURPOSE: Chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) are rare autoimmune diseases. Guidelines were published in 2010 for their diagnosis and treatment. In France, intravenous immunoglobulins (IVIGs) are mainly used for the first-line treatment. The burden of healthcare costs is often underlined but rarely studied. The aim of this survey was to compare to guidelines, the daily practice of French neurologists with IVIGs for CIDP and MMN treatment. METHODS: This was a retrospective observational study consisting of an online questionnaire performed between March and May 2014. A total of 49 questionnaires were included, a quarter of which were from neurologists working in neuromuscular reference centers (NRCs). RESULTS: A total of 182 patient case reports were studied. Patients were referred to an NRC for initial diagnosis in approximately 30% of cases in CIDP and 50% of cases in MMN. The initial management of IVIG (frequency, dose and duration) was not different between NRCs and non-NRCs. Guidelines were followed and neurologists were relatively at ease in diagnosing and treating patients. CONCLUSIONS: This was the first national study to describe the implementation of the European Federation of Neurological Sciences/Peripheral Nerve Society guidelines in the daily management of IVIGs in patients with MMN and CIDP in France. Efforts are needed to improve long-term tailored treatment and home treatment to reduce economic costs.

Phenotypic spectrum of Charcot-Marie-Tooth disease due to LITAF/SIMPLE mutations: a study of 18 patients.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth (CMT) 1C due to mutations in LITAF/SIMPLE is a rare subtype amongst the autosomal dominant demyelinating forms of CMT. Our objective was to report the clinical and electrophysiological characteristics of 18 CMT1C patients and compare them to 20 patients with PMP22 mutations: 10 CMT1A patients and 10 patients with hereditary neuropathy with liability to pressure palsies (HNPP). METHODS: Charcot-Marie-Tooth 1C patients were followed-up in referral centres for neuromuscular diseases or were identified by familial survey. All CMT1A and HNPP patients were recruited at the referral centre for neuromuscular diseases of Pitié-Salpêtrière Hospital. RESULTS: Two phenotypes were identified amongst 18 CMT1C patients: the classical CMT form ('CMT-like', 11 cases) and a predominantly sensory form ('sensory form', seven cases). The mean CMT neuropathy score was 4.45 in CMT1C patients. Motor nerve conduction velocities in the upper limbs were significantly more reduced in CMT1A than in CMT1C patients. On the other hand, the motor nerve conduction velocity of the median nerve was significantly lower in CMT1C compared to the HNPP group. Distal motor latency was significantly more prolonged in CMT1A patients compared to the CMT1C and HNPP groups, the latter two groups having similar distal motor latency values. Molecular analysis revealed five new LITAF/SIMPLE mutations (Ala111Thr, Gly112Ala, Trp116Arg, Pro135Leu, Arg160Cys). CONCLUSIONS: Our study delineates CMT1C as mostly a mild form of neuropathy, and gives clinical and electrophysiological clues differentiating CMT1C from CMT1A and HNPP. Delineating phenotypes in CMT subtypes is important to orient molecular diagnosis and to help to interpret complex molecular findings.

Genome-wide significant risk factors for Alzheimer's disease: role in progression to dementia due to Alzheimer's disease among subjects with mild cognitive impairment.

Few data are available concerning the role of risk markers for Alzheimer's disease (AD) in progression to AD dementia among subjects with mild cognitive impairment (MCI). We therefore investigated the role of well-known AD-associated single-nucleotide polymorphism (SNP) in the progression from MCI to AD dementia. Four independent MCI data sets were included in the analysis: (a) the German study on Aging, Cognition and Dementia in primary care patients (n=853); (b) the German Dementia Competence Network (n=812); (c) the Fundació ACE from Barcelona, Spain (n=1245); and (d) the MCI data set of the Amsterdam Dementia Cohort (n=306). The effects of single markers and combined polygenic scores were measured using Cox proportional hazards models and meta-analyses. The clusterin (CLU) locus was an independent genetic risk factor for MCI to AD progression (CLU rs9331888: hazard ratio (HR)=1.187 (1.054-1.32); P=0.0035). A polygenic score (PGS1) comprising nine established genome-wide AD risk loci predicted a small effect on the risk of MCI to AD progression in APOE-ɛ4 (apolipoprotein E-ɛ4) carriers (HR=1.746 (1.029-2.965); P=0.038). The novel AD loci reported by the International Genomics of Alzheimer's Project were not implicated in MCI to AD dementia progression. SNP-based polygenic risk scores comprising currently available AD genetic markers did not predict MCI to AD progression. We conclude that SNPs in CLU are potential markers for MCI to AD progression.

JCV serology in time: 3 years of follow-up.

OBJECTIVES: Although many neurologists are reluctant to use natalizumab in MS (multiple sclerosis) given the increased risk for PML (progressive multifocal leukoencephalopathy), trust was regained with the introduction of JCV antibody titres as a potent disease-modifying therapy. Literature shows that in patients with a negative JCV serology, the risk of PML is virtually non-existent. Unfortunately, seroconversion causes concern amongst many neurologists. Furthermore, when patients seroconvert, it is still unclear what the risk is of passing the important threshold of 1.5. MATERIALS & METHODS: JCV serology data of 161 patients were analysed, upon treatment with natalizumab at the University Hospital in Lille, France, between May 2012 and November 2014. RESULTS: Of the 81 patients who tested negative for JCV antibody at baseline, 23 (28.3%) seroconverted but only seven (8.6%) passed the threshold of 1.5. Of the 80 patients testing positive for JCV antibody at baseline, eight had an initial JCV antibody titre of 0.9 or lower of which only one of eight (12.5%) patients passed the threshold of 1.5 in the following 3 years. Eight of 15 (53.3%) patients passed this threshold if the initial serology was higher than 0.9. CONCLUSIONS: JCV-negative patients and JCV-positive patients with antibody levels below or equal to 0.9 both have a low risk of surpassing the 1.5 threshold.

Two cases of relapses in primary progressive multiple sclerosis after fingolimod withdrawal.

We report two cases of primary progressive multiple sclerosis (PPMS) included in the INFORMS cohort, experiencing a relapse related to a single MRI gadolinium-enhancing lesion 3 months after fingolimod withdrawal. These two patients share similarities with relapsing-remitting multiple sclerosis cases described in the same situation, suggesting that the initiating process of the active demyelinating plaques is also present in PPMS, even without relapses, but may be triggered as fingolimod is withdrawn. Although the results of the INFORMS study suggest that fingolimod may not slow down the progression, some PPMS patients might still benefit from a disease-modifying treatment.

Genome-wide analysis implicates microRNAs and their target genes in the development of bipolar disorder.

Bipolar disorder (BD) is a severe and highly heritable neuropsychiatric disorder with a lifetime prevalence of 1%. Molecular genetic studies have identified the first BD susceptibility genes. However, the disease pathways remain largely unknown. Accumulating evidence suggests that microRNAs, a class of small noncoding RNAs, contribute to basic mechanisms underlying brain development and plasticity, suggesting their possible involvement in the pathogenesis of several psychiatric disorders, including BD. In the present study, gene-based analyses were performed for all known autosomal microRNAs using the largest genome-wide association data set of BD to date (9747 patients and 14 278 controls). Associated and brain-expressed microRNAs were then investigated in target gene and pathway analyses. Functional analyses of miR-499 and miR-708 were performed in rat hippocampal neurons. Ninety-eight of the six hundred nine investigated microRNAs showed nominally significant P-values, suggesting that BD-associated microRNAs might be enriched within known microRNA loci. After correction for multiple testing, nine microRNAs showed a significant association with BD. The most promising were miR-499, miR-708 and miR-1908. Target gene and pathway analyses revealed 18 significant canonical pathways, including brain development and neuron projection. For miR-499, four Bonferroni-corrected significant target genes were identified, including the genome-wide risk gene for psychiatric disorder CACNB2. First results of functional analyses in rat hippocampal neurons neither revealed nor excluded a major contribution of miR-499 or miR-708 to dendritic spine morphogenesis. The present results suggest that research is warranted to elucidate the precise involvement of microRNAs and their downstream pathways in BD.

Brain Magnetic Susceptibility Changes in Patients with Natalizumab-Associated Progressive Multifocal Leukoencephalopathy.

We investigated the brain magnetic susceptibility changes induced by natalizumab-associated progressive multifocal leukoencephalopathy. We retrospectively included 12 patients with natalizumab-progressive multifocal leukoencephalopathy, 5 with progressive multifocal leukoencephalopathy from other causes, and 55 patients with MS without progressive multifocal leukoencephalopathy for comparison. MR imaging examinations included T2* or SWI sequences in patients with progressive multifocal leukoencephalopathy (86 examinations) and SWI in all patients with MS without progressive multifocal leukoencephalopathy. Signal abnormalities on T2* and SWI were defined as low signal intensity within the cortex and/or U-fibers and the basal ganglia. We observed T2* or SWI signal abnormalities at the chronic stage in all patients with progressive multifocal leukoencephalopathy, whereas no area of low SWI signal intensity was detected in patients without progressive multifocal leukoencephalopathy. Among the 8 patients with asymptomatic natalizumab-progressive multifocal leukoencephalopathy, susceptibility changes were observed in 6 (75%). The basal ganglia adjacent to progressive multifocal leukoencephalopathy lesions systematically appeared hypointense by using T2* and/or SWI. Brain magnetic susceptibility changes may be explained by the increased iron deposition and constitute a useful tool for the diagnosis of progressive multifocal leukoencephalopathy.

Somatosensory evoked potentials in the assessment of peripheral neuropathies: Commented results of a survey among French-speaking practitioners and recommendations for practice.

BACKGROUND: Somatosensory evoked potentials (SSEPs) are increasingly performed for the assessment of peripheral neuropathies, but no practical guidelines have yet been established in this specific application. STUDY AIM: To determine the relevant indication criteria and optimal technical parameters for SSEP recording in peripheral neuropathy investigation. METHODS: A survey was conducted among the French-speaking practitioners with experience of SSEP recording in the context of peripheral neuropathies. The results of the survey were analyzed and discussed to provide recommendations for practice. RESULTS: SSEPs appear to be a second-line test when electroneuromyographic investigation is not sufficiently conclusive, providing complementary and valuable information on central and proximal peripheral conduction in the somatosensory pathways. CONCLUSIONS: Guidelines for a standardized recording protocol, including the various parameters to be measured, are proposed. CLINICAL RELEVANCE: We hope that these proposals will help to recognize the value of this technique in peripheral neuropathy assessment in clinical practice.

Bethlem myopathy: long-term follow-up identifies COL6 mutations predicting severe clinical evolution.

OBJECTIVE: Mutations in one of the 3 genes encoding collagen VI (COLVI) are responsible for a group of heterogeneous phenotypes of which Bethlem myopathy (BM) represents the milder end of the spectrum. Genotype-phenotype correlations and long-term follow-up description in BM remain scarce. METHODS: We retrospectively evaluated the long-term clinical evolution, and genotype-phenotype correlations in 35 genetically identified BM patients (23 index cases). RESULTS: Nineteen patients showed a typical clinical picture with contractures, proximal weakness and slow disease progression while 11 presented a more severe evolution. Five patients showed an atypical presentation, namely a limb girdle muscle weakness in 2 and a congenital myopathy pattern with either no contractures, or only limited to ankles, in 3 of them. Pathogenic COL6A1-3 mutations were mostly missense or in frame exon-skipping resulting in substitutions or deletions. Twenty one different mutations were identified including 12 novel ones. The mode of inheritance was, autosomal dominant in 83% of the index patients (including 17% (N=4) with a de novo mutation), recessive in 13%, and undetermined in one patient. Skipping of exon 14 of COL6A1 was found in 35% of index cases and was mostly associated with a severe clinical evolution. Missense mutations were detected in 39% of index cases and associated with milder forms of the disease. CONCLUSIONS: Long-term follow-up identified important phenotypic variability in this cohort of 35 BM patients. However, worsening of the functional disability appeared typically after the age of 40 in 47% of our patients, and was frequently associated with COL6A1 exon 14 skipping.

Observed costs and health care use of children in a prospective cohort study on community-acquired pneumonia in Geneva, Switzerland.

QUESTIONS UNDER STUDY: Despite various efforts to estimate cost-effectiveness of pneumococcal conjugate vaccines, only scarce information on the cost burden of paediatric community acquired pneumonia (CAP) exists. The objective of this study was to prospectively calculate direct and indirect costs associated with treatment of CAP from a society perspective in children between 2 months and 16 years of age seeking care at a tertiary hospital in Geneva, Switzerland between December 2008 and May 2010. METHODS: This cost of illness study population comprised children aged from 2 months to 16 years of age seeking care for CAP at the University Children's Hospital Geneva from January 2008 through May 2010 (a subset of patients taken from a larger multicentre prospective cohort). Hospital-associated costs for episodes of pneumonia were computed according to the REKOLE® system. Non-hospital costs were estimated by parental interviews at baseline and follow-up on day 14. RESULTS: The overall cost for one episode of CAP was 11'258 CHF; 23'872 CHF for inpatient treatment and 1009 CHF for outpatient treatment. Severe pneumonia cases per World Health Organisation (WHO) definition used significantly more hospital resources than non-severe cases: 21'842 CHF versus 3'479 CHF (p <0.0001). CONCLUSION: Childhood CAP results in a significant medical cost burden that may have been underestimated in previous cost-effectiveness analyses of pneumococcal vaccine strategies.

Follow-up of loci from the International Genomics of Alzheimer's Disease Project identifies TRIP4 as a novel susceptibility gene.

To follow-up loci discovered by the International Genomics of Alzheimer's Disease Project, we attempted independent replication of 19 single nucleotide polymorphisms (SNPs) in a large Spanish sample (Fundació ACE data set; 1808 patients and 2564 controls). Our results corroborate association with four SNPs located in the genes INPP5D, MEF2C, ZCWPW1 and FERMT2, respectively. Of these, ZCWPW1 was the only SNP to withstand correction for multiple testing (P=0.000655). Furthermore, we identify TRIP4 (rs74615166) as a novel genome-wide significant locus for Alzheimer's disease risk (odds ratio=1.31; confidence interval 95% (1.19-1.44); P=9.74 × 10(-)(9)).

Accuracy of postcontrast 3D turbo spin-echo MR sequence for the detection of enhanced inflammatory lesions in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Therapeutic strategies for patients with MS partly rely on contrast-enhanced MR imaging. Our aim was to assess the diagnostic performance of 3D turbo spin-echo MR imaging with variable refocusing flip angles at 3T for the detection of enhanced inflammatory lesions in patients with multiple sclerosis. MATERIALS AND METHODS: Fifty-six patients with MS were prospectively investigated by using postcontrast T1-weighted axial 2D spin-echo and 3D TSE MR images. The order in which both sequences were performed was randomized. Axial reformats from 3D T1 TSE were generated to match the 2D spin-echo images. The reference standard was defined by using clinical data and all MR images available. Three separate sets of MR images (2D spin-echo images, axial reformats, and multiplanar images from 3D TSE sequences) were examined in a blinded fashion by 2 neuroradiologists separately for the detection of enhanced MS lesions. Image artifacts and contrast were evaluated. RESULTS: No artifacts related to vascular pulsation were observed on 3D TSE images, whereas image artifacts were demonstrated on 2D spin-echo images in 41 patients. One hundred twelve enhanced MS lesions were identified in 19 patients. Sixty-four lesions were correctly diagnosed by using 2D spin-echo images; 90, by using 3D TSE axial reformatted views; and 106, by using multiplanar analysis of the 3D TSE sequence. Multiplanar analysis was 94.7% sensitive and 100% specific for the diagnosis of patients with at least 1 enhanced lesion. Contrast of enhanced MS lesions was significantly improved by using the 3D TSE sequence (P < .011). CONCLUSIONS: The 3D TSE sequence with multiplanar analysis is a useful tool for the detection of enhanced MS lesions.

[Current issues in hereditary neuropathies]. / Actualités dans les neuropathies héréditaires.

This short review highlights five studies published in 2012 in the field of Charcot-Marie-Tooth disease (CMT) and transthyretin familial amyloid neuropathies (TTR-FAN). Regarding CMT, an Australian pediatric study shows the high prevalence of impaired speech perception and hearing disability in children with CMT1 or CMT2 with normal or near normal audiometry (Rance et al., 2012). In a second study, the clinical and electrophysiological characteristics of 14 patients with CMT4C due to mutations in SH3TC2 gene are described (Yger et al., 2012). The 3 clinical hallmarks of CMT4C patients in this French cohort are the high prevalence of scoliosis, the proximal motor weakness and the cranial nerves involvement. Concerning TTR-FAN, the first data from French and international registries are reported (Adams et al., 2012; Coelho et al., 2013) and a phase II trial describes the results of taurourodeoxycholic acid and doxycycline treatment (Obici et al., 2012).

The French Pompe registry. Baseline characteristics of a cohort of 126 patients with adult Pompe disease.

Pompe disease is a rare autosomal recessive muscle lysosomal glycogenosis, characterised by limb-girdle muscle weakness and frequent respiratory involvement. The French Pompe registry was created in 2004 with the initial aim of studying the natural history of French patients with adult Pompe disease. Since the marketing in 2006 of enzyme replacement therapy (alglucosidase alfa, Myozyme(®)), the French Pompe registry has also been used to prospectively gather the biological and clinical follow-up data of all adult patients currently treated in France. This report describes the main clinical and molecular features, at the time of inclusion in the French registry, of 126 patients followed up in 21 hospital-based neuromuscular or metabolic centres. Sixty-five men and 61 women have been included in the registry. Median age at inclusion was 49 years, and the median age at onset of progressive limb weakness was 35 years. Fifty-five percent of the patients were walking without assistance, 24% were using a stick or a walking frame, and 21% were using a wheelchair. Forty-six percent of the patients needed ventilatory assistance, which was non-invasive in 35% of the cases. When performed, muscle biopsies showed specific features of Pompe disease in less than two-thirds of the cases, confirming the importance of acid alpha-glucosidase enzymatic assessment to establish the diagnosis. Molecular analysis detected the common c.-32-13T>G mutation, in at least one allele, in 90% of patients. The French Pompe registry is so far the largest country-based prospective study of patients with Pompe disease, and further analysis will be performed to study the impact of enzyme replacement therapy on the progression of the disease.

[Charcot-Marie-Tooth disease associated with periaxin mutations (CMT4F): Clinical, electrophysiological and genetic analysis of 24 patients]. / Maladie de Charcot-Marie-Tooth associée au gène de la périaxine (CMT4F) : description clinique, électrophysiologique et génétique de 24 patients.

Autosomal recessive Charcot-Marie-Tooth disease (AR-CMT) is often characterized by onset in early childhood and severe phenotype compared to the dominant forms. CMT disease associated with periaxin gene (PRX) is rare and characterized by demyelination limited to the major peripheral nerves. Following the discovery of a high frequency of a specific periaxin gene mutation (E1085fsX4 homozygote) in the Reunion Island, we examined all French patients known as carriers of the periaxin gene mutation. There were 24 patients. Eighteen were from the Reunion Island (6 families and 10 sporadic cases). The six remaining patients were in two families, each with two affected individuals, and two sporadic cases. The series included 17 female and seven male patients. Walking was acquired late, on average at 3.4±1.6 years. One patient never learned to walk. The Charcot Marie Tooth Neuropathy Score (CMTNS) averaged 24.5±8.1. Seven patients had been wheelchair-bound since the age of 24±22. Other symptoms were: scoliosis most often observed after the age of 12 years and sometimes complicated by a restrictive respiratory syndrome; foot deformity in 24 patients; strabismus; glaucoma; myopia. When conduction recordings are available, median nerve motor conduction was slow (<10m/s), associated with a major lengthening of distal latencies. Study of the periaxin gene should be considered in patients with severe demyelinating neuropathy associated with early infantile scoliosis. This disease leads to major disability (29% of patients in this series were wheelchair-bound) and to respiratory insufficiency. Genetic counselling is highly recommended for consanguineous families.

[Respiratory failure due to acid maltase deficiency]. / Déficit en maltase acide (glycogénose de type 2) de l'adulte. Une cause d'insuffisance respiratoire à ne pas méconnaître.

Acid maltase deficiency (AMD) is a metabolic myopathy which may be revealed at adulthood by respiratory muscle weakness, resulting in reduced vital capacity, alveolar hypoventilation and sleep apnoea. We observed two men, 39 and 42 years old respectively, suffering from asthenia and exertional dyspnoea for several months. After a stay in the intensive care unit, as a result of respiratory failure associated with pneumonia, these patients were referred to the respiratory medicine unit on account of persistent hypercapnia during the day and a fall in oxygen saturation at night. The investigations revealed proximal muscle weakness, a reduced vital capacity, alveolar hypoventilation (PaCO2: 67 and 49 mmHg), reduced maximum static inspiratory and expiratory pressures, carbon dioxide hyporesponsiveness and sleep apnoea on overnight polysomnography. Electromyography showed a myopathic pattern. Muscle biopsy confirmed the diagnosis of AMD. Non-invasive ventilation overnight partially corrected the clinical symptoms and the resting hypercapnia in both patients. The adulthood form of AMD is a rare disease that should be considered in a large number of clinical situations, particularly in unexplained respiratory failure. Our observations suggest that non invasive ventilation together with enzyme supplementation (Myozyme®) is effective in correcting alveolar hypoventilation.

Clinical and electrophysiological characteristics of neuropathy associated with Tangier disease.

Tangier disease (TD) (OMIM#205400) is a rare autosomal recessive disorder resulting from mutations in the ABCA1 gene, leading to decreased levels of plasma high-density lipoproteins (HDL). Peripheral neuropathy is a common finding in this disease, and may present as relapsing/remitting mono/polyneuropathies or as syringomyelia-like neuropathy. We retrospectively analyzed four patients, and report here their clinical, biological, electrophysiological, imaging, and genetic findings. Three patients had a typical pseudosyringomyelic neuropathy including facial diplegia, but asymmetrical onset was observed in one patient who had first been misdiagnosed with Lewis-Sumner syndrome. Electrophysiological pattern was heterogeneous, showing both signs of demyelination and axonal degeneration. Truncating mutations of the ABCA1 gene, including two previously undescribed mutations, were constantly found. Atypical symptom onset and demyelinating features on electrophysiological examination can be misleading in case of pseudosyringomyelic neuropathy. These reports illustrate two different neurological phenotypes in TD, namely the pseudosyringomyelic type and the Lewis-Sumner-like type, and advocate for a systematic assessment of lipid profile including HDL cholesterol in demyelinating neuropathies.