Comparison of Lewis-Sumner syndrome with chronic inflammatory demyelinating polyradiculoneuropathy patients in a tertiary care centre.

BACKGROUND AND PURPOSE: Whether the Lewis-Sumner syndrome (L-SS) is a distinct entity from other types of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP-ot) remains controversial. METHOD: The clinical/electrophysiological characteristics and long-term outcomes of 45 L-SS and 35 CIDP-ot patients were retrospectively compared. RESULTS: The CIDP-ot group was composed of 11 patients with a typical CIDP, 17 with a pure sensory form, four with a distal form and three with a pure motor form. In the L-SS group, asymmetric (P < 0.001) and monomelic involvement (P = 0.04) of the upper limbs (P < 0.001) was significantly more frequent; paucisymptomatic forms (Overall Neuropathy Limitations Scale ≤ 1) were less frequent (P < 0.001); electroneuromyography showed that conduction block in intermediate nerve segments was the main demyelinating feature, with frequent F-wave abnormalities on nerves without conduction block (44%). Long-term prognosis was globally poorer in the L-SS group with more frequent aggravation during treatment (P = 0.02), less frequent treatment withdrawal (P = 0.03) and longer time to achieve successful withdrawal (39 vs. 15 months). CONCLUSIONS: Our study suggests that L-SS patients have a less favourable therapeutic response rate and long-term outcomes. Rapid differentiation of L-SS from other forms of CIDP is important in order to anticipate a more complicated disease course management, with from one side the inefficacy or even harmfulness of corticosteroids and from the other side a difficult weaning procedure. A prospective study is necessary to confirm these results.

Sensory neuronopathy as a major clinical feature of mitochondrial trifunctional protein deficiency in adults.

INTRODUCTION: Mitochondrial trifunctional protein deficiency (MTPD) is a long-chain fatty acid oxidation disorder characterized by co-existence of rhabdomyolysis episodes and peripheral neuropathy. Two phenotypes are described: generalized mitochondrial trifunctional protein deficiency (gMTPD) and isolated long-chain-3-hydroxyacyl-CoA dehydrogenase deficiency (iLCHADD) that is always associated with the c.1528G>C mutation. Peripheral neuropathy of MTPD is commonly described in children as axonal, length-dependent and sensorimotor. OBJECTIVES: To report clinical and electrophysiological features of four independent adult MTPD patients with peripheral neuropathy. RESULTS: Onset of the disease was characterized in all patients by rhabdomyolysis episodes occurring during childhood preceded by severe hypoglycemic episodes in three patients. Peripheral nerve involvement manifesting as sensory ataxia appeared later, during adolescence or adulthood. In all cases, electroneuromyogram showed no length-dependent sensory potentials decrease characteristic of sensory neuronopathy ("ganglionopathy"). All patients harbored at least one c.1528G>C mutation. DISCUSSION: We describe MTPD as a newly hereditary etiology of sensory neuronopathy in adults, specifically in patients with c.1528G>C mutation. MTPD should be screened for by performing plasma acylcarnitines in patients with chronic sensory neuronopathy and additional suggestive features such as exercise intolerance or retinopathy.

Diagnostic potential of sarcoplasmic myxovirus resistance protein A expression in subsets of dermatomyositis.

AIMS: To elucidate the diagnostic value of sarcoplasmic expression of myxovirus resistance protein A (MxA) for dermatomyositis (DM) specifically analysing different DM subforms, and to test the superiority of MxA to other markers. METHODS: Immunohistochemistry for MxA and retinoic acid-inducible gene I (RIG-I) was performed on skeletal muscle samples and compared with the item presence of perifascicular atrophy (PFA) in 57 DM patients with anti-Mi-2 (n = 6), -transcription intermediary factor 1 gamma (n = 10), -nuclear matrix protein 2 (n = 13), -melanoma differentiation-associated gene 5 (MDA5) (n = 10) or -small ubiquitin-like modifier activating enzyme (n = 1) autoantibodies and with no detectable autoantibody (n = 17). Among the patients, nine suffered from cancer and 22 were juvenile-onset type. Disease controls included antisynthetase syndrome (ASS)-associated myositis (n = 30), immune-mediated necrotizing myopathy (n = 9) and inclusion body myositis (n = 5). RESULTS: Sarcoplasmic MxA expression featured 77% sensitivity and 100% specificity for overall DM patients, while RIG-I staining and PFA reached respectively 14% and 59% sensitivity and 100% and 86% specificity. In any subset of DM, sarcoplasmic MxA expression showed higher sensitivity than RIG-I and PFA. Some anti-MDA5 antibody-positive DM samples distinctively showed a scattered staining pattern of MxA. No ASS samples had sarcoplasmic MxA expression even though six patients had DM skin rash. CONCLUSIONS: Sarcoplasmic MxA expression is more sensitive than PFA and RIG-I expression for a pathological diagnosis of DM, regardless of the autoantibody-related subgroup. In light of its high sensitivity and specificity, it may be considered a pathological hallmark of DM per se. Also, lack of MxA expression in ASS supports the idea that ASS is a distinct entity from DM.

Antineoplastic agents exacerbating Charcot Marie Tooth disease: red flags to avoid permanent disability.

BACKGROUND: Charcot Marie Tooth (CMT) disease is the most common form of hereditary neuropathy. Due to the high prevalence of mild and undiagnosed forms, patients with CMT disease may be exposed to severe neurotoxicity following the administration of neurotoxic chemotherapies. The aim of this report is to alert oncologists to the potential to precipitate severe irreversible peripheral neuropathies when administering neurotoxic compounds to undiagnosed CMT patients. MATERIAL AND METHODS: A retrospective research in the OncoNeuroTox database was performed (2010-2016), searching for patients with the diagnosis of chemotherapy-induced peripheral neuropathy (CIPN) and CMT disease. A comprehensive literature review for previously published cases was performed using the Pubmed and Cochrane databases (1972-2017). RESULTS: Among 428 patients with CIPN, we identified eight patients with concomitant CMT disease. Seven patients out of the eight had no previous diagnosis of CMT disease, although accurate familial history disclosed mild signs of peripheral neuropathy in five cases. Patients themselves had minor stigmata of long-standing peripheral damage. Patients received chemotherapy regimens based on vinca alkaloids, taxanes or a combination of vinca alkaloids and platinum compounds. In two cases, cumulative doses were below or equal to the expected neurotoxic threshold. Following chemotherapy administration, patients developed severe length-dependent sensory-motor deficits. Despite early drug discontinuation, most patients remained severely disabled. CONCLUSION: A brief checklist to disclose long-standing signs of peripheral neuropathy could be helpful to detect patients with undiagnosed hereditary neuropathies who could be at risk of developing severe irreversible neurotoxicity following the administration of neurotoxic agents.

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.

Myofibrillar myopathies: State of the art, present and future challenges.

Myofibrillar myopathies (MFM) have been described in the mid-1990s as a group of diseases sharing common histological features, including an abnormal accumulation of intrasarcoplasmic proteins, the presence of vacuoles and a disorganization of the intermyofibrillar network beginning at the Z-disk. The boundaries of this concept are still uncertain, and whereas six genes (DES, CRYAB, LDB3/ZASP, MYOT, FLNC and BAG3) are now classically considered as responsible for MFM, other entities such as FHL1 myopathy or Hereditary Myopathy with Early Respiratory Failure linked to mutations of titin can now as well be included in this group. The diagnosis of MFM is not always easy; as histological lesions can be focal, and muscle biopsy may be disappointing; this has led to a growing importance of muscle imaging, and the selectivity of muscle involvement has now been described in several disorders. Due to the rarity of these myopathies, if some clinical patterns (such as distal myopathy associated with cardiomyopathy due to desmin mutations) are now well known, surprises remain possible and should lead to systematic testing of the known genes in case of a typical histological presentation. In this paper, we aim at reviewing the data acquired on the six main genes listed above as well as presenting the experience from two French reference centres, Paris and Marseilles.

[Neurologic paraneoplastic syndrome with anti-CV2/CRMP5 antibodies revealing a small cell lung cancer. Effectiveness of the lung cancer treatment]. / Syndrome neurologique paranéoplasique à anticorps anti-CV2/CRMP5 révélateur d'un cancer bronchique à petites cellules. Efficacité du traitement du cancer bronchique.

INTRODUCTION: Paraneoplastic neurological syndrome associated with anti-CV2/CRMP5 antibodies are rare. Various clinical manifestations can occur, cerebellar ataxia, polyneuropathy, optic neuritis with NORB or uveitis. Small cell lung carcinoma is generally responsible. CASE REPORT: We report the case of a 64-year-old man who developed visual symptoms with papilledema, cerebellar signs, polyneuropathy confirmed with a neurophysiological studies. Anti-CV2/CRMP5 antibodies were present. A small cell lung carcinoma was responsible for this paraneoplastic syndrome revealing the cancer. The paraneoplastic syndrome improved with radio chemotherapy of the cancer alone. CONCLUSION: A paraneoplastic neurological syndrome must be evoked in case of an atypic neurological syndrome. This diagnostic can be confirmed by the presence of anti-neuronal antibodies. In this case, a small cells cancer of the lung must be research.

[Radiation-induced neuropathies: collateral damage of improved cancer prognosis]. / Neuropathies post-radiques: un dommage collatéral chez les patients cancéreux long-survivants.

INTRODUCTION: Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. STATE OF THE ART: Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. PERSPECTIVES AND CONCLUSION: The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and inflammation. A phase III trial evaluating the association of pentoxifylline, tocopherol and clodronate (PENTOCLO, NCT01291433) in radiation-induced neuropathies is now recruiting.

Lambert-Eaton myasthenic syndrome and follicular thymic hyperplasia in systemic lupus erythematosus.

Fatigue is a prominent feature of systemic lupus erythematosus (SLE), usually ascribed to various factors, such as muscle or joint involvement, anaemia or depression. The Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoantibody-mediated disorder of neuro-muscular transmission. We report on a well-defined LEMS associated with thymus hyperplasia in a SLE patient. An African 41 years-old SLE patient presented with persisting fatigue, myalgia and dyspnea, abolished reflexes and a bilateral ptosis. Neuromuscular electrodiagnostic study showed a clear-cut potentiation that was typical of a pre-synaptic neuromuscular junction disease. Anti-calcium gated channels antibodies were disclosed in serum and a diagnosis of LEMS was made. A total body CT-scan revealed an antero-superior mediastinal mass, compatible with thymoma. The tumour was surgically removed with a final diagnosis of follicular thymic hyperplasia. In conclusion, our observation provides a new example of entangled organ-specific and systemic autoimmunity in the context of thymus pathology. Potentiation study during electromyography should be performed systematically to rule out LEMS in patients with SLE and muscle weakness.

Non-anti-MAG DADS neuropathy as a variant of CIDP: clinical, electrophysiological, laboratory features and response to treatment in 10 cases.

BACKGROUND AND PURPOSE: Some patients within the spectrum of chronic inflammatory demyelinating polyradiculoneuropathies (CIDP) have distal acquired demyelinating symmetric (DADS) neuropathy, usually associated with anti-myelin-associated-glycoprotein (MAG) IgM monoclonal gammopathy. The aim of this retrospective study was to investigate patients with DADS neuropathy without anti-MAG antibodies, and study their response to immunotherapy. METHODS: Patients were selected on the basis of (i) 'Definite CIDP' according to the EFNS/PNS Guideline criteria, (ii) The presence of disproportionately prolonged motor latencies resulting in a terminal latency index (TLI) ≤ 0.25 in at least two motor nerves and (iii) The absence of anti-MAG antibodies on ELISA. Response to immunotherapy was defined as persistent improvement by at least one point on the INCAT disability score. RESULTS: Data from 146 CIDP patients were analysed, and 10 patients were included. Six had clinically pure sensory neuropathy, and four had sensorimotor neuropathy. Ataxia was present in nine patients, generalized areflexia in seven and postural tremor in two. Five of the 10 patients had abnormal sensory potentials only in the upper limbs. An associated condition was found in nine patients: two chronic lymphocytic leukaemias, four IgG monoclonal gammopathies (one associated with non-Hodgkin's lymphoma) and two IgM monoclonal gammopathies of unknown significance. Patients were mostly improved with intravenous immunoglobulin (IVIg), corticosteroids, plasma exchanges, or a combination thereof. CONCLUSION: DADS neuropathy without anti-MAG antibodies is more likely to be considered a variant of CIDP. In addition, such patients should be systematically investigated for an associated haematological or immunological condition.

Diagnostic value of markers of muscle degeneration in sporadic inclusion body myositis.

Sporadic inclusion body myositis (s-IBM) is characterized histologically by the association of concomitant inflammatory and degenerative processes. We evaluated the sensitivity and specificity of different markers of the degenerative process in order to refine the histological diagnosis. We performed an immunohistochemical study with antibodies directed against ubiquitin, amyloid-beta precursor protein (AbetaPP), amyloid-beta (Abeta), SMI-31, SMI-310, Tar-DNA binding protein-43 (TDP-43) and p62 on s-IBM and control muscle biopsies. Based on conventional stains 36 patients with characteristic clinical features of s-IBM were subclassified as presumed definite s-IBM (d s-IBM, n = 17) or possible s-IBM (p s-IBM, n = 19) according to the presence or absence of vacuolated muscle fibers. Immunohistochemically, TDP-43 and p62 were the most sensitive markers, accumulating in all d s-IBM and in 31% and 37%, respectively, of the p s-IBM cases and thus enabling reclassification of these cases as d s-IBM. We recommend using TDP-43 and p62 antibodies in the histological diagnosis workup of s-IBM. The specificity of these markers has to be further validated in prospective series.

Neurolymphomatosis related to direct epineural invasion of the superficial peroneal nerve from subcutaneous B-cell lymphoma.

Neurolymphomatosis is a rare complication of systemic lymphomas, and is classically related to hematogenous spread or intraneural spread of tumor cells from the leptomeninges. Here we report a case of neurolymphomatosis related to direct epineural invasion of the superficial peroneal nerve from subcutaneous localization of B-cell lymphoma. Nerve biopsy revealed striking histological features suggestive of contiguous infiltration of the superficial peroneal nerve by subcutaneous lymphoma. We think this case report sheds new light on neurolymphomatosis pathophysiology with an unreported mechanism in B-cell lymphoma. It also points out that the clinical spectrum in neurolymphomatosis is really variable, pure sensory mononeuritis being a rare presentation. Finally, our case is also strongly illustrative of the contribution of early nerve ultrasonography in the patient diagnosis and in guidance of the nerve biopsy.

[Cryoglobulinemic peripheral neuropathy in hepatitis C virus infection: clinical and anatomical correlations of 22 cases]. / Corrélations anatomocliniques des neuropathies périphériques cryoglobulinémiques secondaires à l'hépatite C. Série consécutive de 22 cas.

INTRODUCTION: Cryoglobulinemic neuropathies caused by hepatitis C virus are frequent and may have severe clinical outcomes. The aim of this study was to clarify the clinical and anatomical correlations of these neuropathies. METHODS: Between 1992 and 2007, 22 consecutive patients with cryoglobulinemic neuropathies caused by hepatitis C virus were retrospectively included. Patients were evaluated clinically, electrophysiologically and underwent a neuromuscular biopsy. The group of patients with vasculitis on nerve biopsy was compared with the group without vasculitis. RESULTS: All the neuropathies were axonal with 11 polyneuropathies and 11 mononeuropathies multiplex. The seven patients with medium-sized vasculitis on the nerve biopsy presented an acute sensorimotor mononeuropathy multiplex in six cases (85%), with ischemic conduction block in three cases (42%) and wallerian degeneration in four cases (57%). Among the four patients with small-sized vasculitis, two had a mononeuropathy multiplex (50%) without conduction block (0%) and with wallerian degeneration in one case (25%). The 11 patients without vasculitis (nine lymphocytic perivascular infiltrates and two non inflammatory biopsies) had a polyneuropathy in eight cases (72%) without conduction block and wallerian degeneration (0%). The type of neuropathy was different in the group of patients with vasculitis compared with the group without vasculitis. The neuropathies with vasculitis were significantly different with more frequent mononeuropathies multiplex (p<0.05), acute early stage (p<0.01), disability (p<0.05) and wallerian degeneration (p=0.01). CONCLUSION: Among hepatitis C patients with cryoglobulinemia, neuropathies with small-sized vasculitis show a pattern between severe mononeuropathies multiplex with medium-sized vasculitis and moderate polyneuropathies with lymphocytic perivascular infiltrates. In cryoglobulinemic vasculitis with hepatitis C, the severity of the neuropathy depends on the nature of the cellular inflammation and the size of the vessel involvement.

[A rare cause of impaired general condition: Muscular and cardiac toxicity of antimalarials]. / Une cause rare d'altération de l'état général : cardiopathie et myopathie aux antipaludéens de synthèse.

INTRODUCTION: This case report signifies the need to systemically assess antimalarial toxicity in those undergoing long-term treatment. CASE REPORT: A 59-year-old man with a history of ischemic-labeled heart disease revealed by conduction disorders and cutaneous lupus treated initially with hydroxychloroquine followed by chloroquine consulted for asthenia and weight loss. Clinically, he had a muscular atrophy, a motor deficit, and an abolition of the osteo-tendinous reflexes in the lower limbs. Adverse drug effects of the antimalarial therapy were suspected-specifically, muscular and cardiac toxicity. The diagnosis was confirmed with a muscle biopsy, which showed typical and florid vacuolar myopathy. Cessation of the drug resulted in a slow regression of symptoms. CONCLUSION: Cardiac and muscular toxicity related to antimalarials are rare and sometimes fatal; thus, they must be systematically assessed in a patient with several years of exposure. A muscle biopsy could be sufficient to allow for the diagnosis.