Search

Introduction: In peripheral neuropathies with antibodies against Myelin Associated Glycoprotein (MAG), an IgM monoclonal gammopathy recognizes a specific epitope called Human Natural Killer 1 (HNK1) shared by NK lymphocytes and several components of the peripheral nerve myelin. Recently an ELISA test has been developed to detect antibodies against HNK1 epitope. Objectives were to determine the usefulness of this assay in the management of anti-MAG neuropathy., Methods: Anti-HNK1 antibodies were assessed with the GanglioCombi™ MAG ELISA test (Buhlmann) in 41 anti-MAG neuropathies and in 118 controls: 34 chronic inflammatory demyelinating polyradiculoneuropathies, 3 Miller Fisher syndromes, 12 sensory neuronopathies, 63 length-dependent axonal sensory polyneuropathies, 6 healthy controls. Anti-HNK1 antibody was tested before and 1 year after rituximab therapy in seven patients with anti-MAG neuropathy., Results: Anti-HNK1 antibodies were positive in 40/41 anti-MAG neuropathies, and in 1/118 controls (sensitivity 98%, specificity 99%). Only considering controls with IgM paraprotein, specificity was 96% (23/24). In anti-MAG neuropathies, anti-HNK1 titre was correlated with sensory deficiency evaluated with the INCAT sensory sum score (r = 0.4, p = 0.01) and with disability evaluated with the Rasch-built Overall Disability Scale (r = [Formula: see text] 0.4, p = 0.01) and Overall Neuropathy Limitation Scale (r = 0.4, p = 0.02). Anti-HNK1 titres were not related to age, disease duration, atypical clinical features and anti-MAG antibodies titres. Anti-MAG titres were not associated with disease severity. Anti-HNK1 titres were decreased by 18% 1 year after rituximab treatment., Conclusions: Anti-HNK1 antibodies have good sensitivity and specificity for the diagnosis of anti-MAG neuropathy. Interestingly, anti-HNK1 titres are related to the disease severity and decrease after rituximab infusions.

Background: Patients with inflammatory sensory neuronopathy (SNN) may benefit from immunomodulatory or immunosuppressant treatments if administered timely. Knowing the temporal profile of neuronal loss in dorsal root ganglia will help to ascertain whether a final diagnosis may be reached before the occurrence of irreversible neuronal injuries. Thus, we addressed the evolution of neuronal loss in SNN by using sensory nerve action potentials (SNAPs) as a surrogate marker of neuron degeneration., Methods: Eighty-six patients with acute/subacute inflammatory SNN (paraneoplastic, associated with dysimmune diseases, or idiopathic) were retrospectively studied. The monthly SNAP reduction was determined and normalized with the lower limit of normal. Disability progression was expressed by the modified Rankin score and correlated with SNAP reduction., Results: The monthly SNAP reduction was similar in the four limbs although the median nerve was less severely affected. The monthly SNAP reduction was very severe within the first two months of evolution, began to slow down after seven months, and stabilized after ten months. It was tightly correlated with disability progression. Kaplan-Meier analysis showed that the median time until matching the diagnostic criteria of SNN was 8.5 months. Within this period, 42% of nerves remained excitable., Conclusions: Developing treatment aiming at the stabilization of SNN is possible within the first 8 months of evolution. An improvement of the disease is possible if patients are treated within two months, which needs an early referral to an expert center and ENMG testing of the radial and ulnar nerves, which are most sensitive to changes., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Introduction: Vincristine is an antimitotic agent used for treatment of leukemia, lymphomas, and cancers. Its main side effect is a dose-related, length-dependent (LD) axonal neuropathy., Methods: We performed electrodiagnostic (EDx) examinations in 17 children who had been treated with vincristine and who presented with the clinical picture of a peripheral neuropathy., Results: The mean dose of vincristine was 8.5 ± 4.0 mg/m(2) . Clinical motor symptoms were more frequent and more severe than sensory ones. Thirteen children presented with a motor deficit, 4 of whom could no longer walk. EDx examination showed an axonal neuropathy with a non-length-dependent (NLD) pattern in 9 children and an LD pattern in 8. A major motor predominance was encountered in 12 patients., Conclusions: The electrophysiological and clinical motor predominance described differs from the mainly sensory neuropathy reported in adults. Incomplete myelination due to young age may have resulted in greater sensitivity of some nerves to neurotoxic agents., (© 2015 Wiley Periodicals, Inc.)

Background: Immunological mechanisms are suspected in sensory neuropathy (SN) occurring with systemic autoimmune diseases and in some idiopathic cases, but so far there are no antibodies (Abs) identifying these neuropathies., Methods: In the search for such specific antibodies, serum samples were collected from 106 patients with SN of these 72 fulfilled the diagnosis criteria of sensory neuronopathy (SNN) and 211 control subjects including patients with sensorimotor neuropathies, other neurological diseases (ONDs), systemic autoimmune diseases and healthy blood donors., Results: In the first step, a protein array with 8000 human proteins allowed identification of the intracellular domain of the fibroblast growth factor receptor 3 (FGFR3) as a target of Abs in 7/16 SNN and 0/30 controls. In the second step, an ELISA method was used to test the 317 patients and controls for anti-FGFR3 Abs. Abs were detected in 16/106 patients with SN and 1/211 controls (p<0.001). Among the 106 patients with SN, anti-FGFR3 Abs were found in 11/38 patients with autoimmune context, 5/46 with idiopathic neuropathy and 0/22 with neuropathy of other aetiology (p=0.006). The only control patient with anti-FGFR3 Abs had lupus and no recorded neuropathy. Sensitivity, specificity, and positive and negative predictive values of anti-FGFR3 Abs for a diagnosis of idiopathic or dysimmune SN were 19%, 99.6%, 94.1% and 77.3%, respectively. A cell-based assay confirmed serum reactivity against the intracellular domain of FGFR3. The neuropathy in patients with anti-FGF3 Abs was non-length dependent in 87% of patients and fulfilled the criteria of probable SNN in 82%. Trigeminal nerve involvement and pain were frequent features., Conclusions: A anti-FGFR3 Abs identify a subgroup of patients with SN in whom an underlying autoimmune disorder affecting sensory neurons in the dorsal root and trigeminal nerve ganglia is suspected., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

There are no validated criteria for the diagnosis of sensory neuronopathy (SNN) yet. In a preliminary monocenter study a set of criteria relying on clinical and electrophysiological data showed good sensitivity and specificity for a diagnosis of probable SNN. The aim of this study was to test these criteria on a French multicenter study. 210 patients with sensory neuropathies from 15 francophone reference centers for neuromuscular diseases were included in the study with an expert diagnosis of non-SNN, SNN or suspected SNN according to the investigations performed in these centers. Diagnosis was obtained independently from the set of criteria to be tested. The expert diagnosis was taken as the reference against which the proposed SNN criteria were tested. The set relied on clinical and electrophysiological data easily obtainable with routine investigations. 9/61 (16.4 %) of non-SNN patients, 23/36 (63.9 %) of suspected SNN, and 102/113 (90.3 %) of SNN patients according to the expert diagnosis were classified as SNN by the criteria. The SNN criteria tested against the expert diagnosis in the SNN and non-SNN groups had 90.3 % (102/113) sensitivity, 85.2 % (52/61) specificity, 91.9 % (102/111) positive predictive value, and 82.5 % (52/63) negative predictive value. Discordance between the expert diagnosis and the SNN criteria occurred in 20 cases. After analysis of these cases, 11 could be reallocated to a correct diagnosis in accordance with the SNN criteria. The proposed criteria may be useful for the diagnosis of probable SNN in patients with sensory neuropathy. They can be reached with simple clinical and paraclinical investigations.

Sensory neuronopathy (SNN) depends on a pathophysiological process that targets the sensory neuron in the posterior root ganglia. These rare diseases are sometimes difficult to diagnose because the site of impairment is not directly assessable by conventional neurophysiological techniques. After recalling the general data concerning SNN, we propose an easy to use clinical and electrophysiological diagnosis criteria and guidelines for clinicians in their search for an etiology in a patient with NNS., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Paraneoplastic neurological syndromes are rare but can affect any part of the peripheral nervous system (PNS) including motor neurons, sensory ganglia, nerve roots, plexuses, cranial and peripheral nerves, and neuromuscular junctions. The type of cancer, lymphoma or solid tumour, is a determinant factor of the underlying mechanism. With solid tumour, antibodies directed to intracellular (anti-Hu or anti-CV2/CRMP5 antibodies) or surface antigens (anti-VGCC,or LGI1 and Caspr2 antibodies) have been identified while with lymphoma, the neuropathy is usually linked to a monoclonal gammopathy. This review discusses the different etiologies and mechanisms of paraneoplastic disorders of the PNS in patients emphasising their evaluation, diagnosis and treatment., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Acquired sensory neuronopathies encompass a group of paraneoplastic, dysimmune, toxic or idiopathic disorders characterized by degeneration of peripheral sensory neurons in dorsal root ganglia. As dorsal root ganglia cannot easily be explored, the clinical diagnosis of these disorders may be difficult. The question as to whether there exists a common clinical pattern of sensory neuronopathies, allowing the establishment of validated and easy-to-use diagnostic criteria, has not yet been addressed. In this study, logistic regression was used to construct diagnostic criteria on a retrospective study population of 78 patients with sensory neuronopathies and 56 with other sensory neuropathies. For this, sensory neuronopathy was provisionally considered as unambiguous in 44 patients with paraneoplastic disorder or cisplatin treatment and likely in 34 with a dysimmune or idiopathic setting who may theoretically have another form of neuropathy. To test the homogeneity of the sensory neuronopathy population, likely candidates were compared with unambiguous cases and then the whole population was compared with the other sensory neuropathies population. Criteria accuracy was checked on 37 prospective patients referred for diagnosis of sensory neuropathy. In the study population, sensory neuronopathy showed a common clinical and electrophysiological pattern that was independent of the underlying cause, including unusual forms with only patchy sensory loss, mild electrical motor nerve abnormalities and predominant small fibre or isolated lower limb involvement. Logistic regression allowed the construction of a set of criteria that gave fair results with the following combination: ataxia in the lower or upper limbs + asymmetrical distribution + sensory loss not restricted to the lower limbs + at least one sensory action potential absent or three sensory action potentials <30% of the lower limit of normal in the upper limbs + less than two nerves with abnormal motor nerve conduction study in the lower limbs.

Involvement of the peripheral nervous system (PNS) is common in patients with cancer and any part, including motor neurons, sensory ganglia, nerve roots, plexuses, cranial and peripheral nerves, and neuromuscular junctions, can be affected. Different mechanisms can initiate damage associated with cancer-related PNS disorders. These include tumour infiltration, toxicity of treatments, metabolic and nutritional perturbations, cachexia, virus infections, and paraneoplastic neurological syndromes. The type of cancer, lymphoma, or solid tumour is a further determinant of a PNS disorder. In this Review we discuss the different causes and mechanisms of disorders of the PNS in patients with cancer and we will focus on their assessment and diagnosis.