Vitamin B12 (B12) deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most ...classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.
Introduction
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a debilitating autoimmune neuropathy that is treated with intravenous immunoglobulin (IVIG). The aim of this ...retrospective study was to investigate the efficacy and safety of the sucrose-free IVIG Octagam® (Octapharma AG, Lachen, Switzerland) in patients with CIDP.
Methods
Data from 47 patients who received at least one dose of Octagam were collected from the records of 11 centres in France. Efficacy was assessed using Overall Neuropathy Limitation Scale (ONLS). Safety was evaluated using adverse event rates.
Results
Data from 24 patients who were IVIG naïve (
n
= 11) or had stopped IVIG ≥ 12 weeks before initiation of Octagam therapy (washout group;
n
= 13) were included in the efficacy analysis. At 4 months post-initiation of Octagam treatment, 41.7% of patients had improved their functional status (decrease of ≥ 1 ONLS score) with a significant change in the ONLS score from baseline (– 0.42;
p
= 0.04; signed test). Functional status was reduced in only two patients: one patient in the IVIG-naïve group and one patient in the IVIG-washout group. All 47 patients were included in the safety analysis, which showed that Octagam was well tolerated, with a frequency of 0.04 adverse events per Octagam course. The most common adverse drug reaction was headache.
Conclusions
These real-life results are consistent with the efficacy and safety of IVIG reported in randomised controlled studies. A long-term prospective study of Octagam in patients with CIDP is warranted.
Funding
Octapharma, France SAS.
CANOMAD (chronic ataxic neuropathy, ophthalmoplegia, immunoglobulin M IgM paraprotein, cold agglutinins, and disialosyl antibodies) is a rare syndrome characterized by chronic neuropathy with sensory ...ataxia, ocular, and/or bulbar motor weakness in the presence of a monoclonal IgM reacting against gangliosides containing disialosyl epitopes. Data regarding associated hematologic malignancies and effective therapies in CANOMAD are scarce. We conducted a French multicenter retrospective study that included 45 patients with serum IgM antibodies reacting against disialosyl epitopes in the context of evocating neurologic symptoms. The main clinical features were sensitive symptoms (ataxia, paresthesia, hypoesthesia; n = 45, 100%), motor weakness (n = 18, 40%), ophthalmoplegia (n = 20, 45%), and bulbar symptoms (n = 6, 13%). Forty-five percent of the cohort had moderate to severe disability (modified Rankin score, 3-5). Cold agglutinins were identified in 15 (34%) patients. Electrophysiologic studies showed a demyelinating or axonal pattern in, respectively, 60% and 27% of cases. All patients had serum monoclonal IgM gammopathy (median, 2.6 g/L; range, 0.1-40 g/L). Overt hematologic malignancies were diagnosed in 16 patients (36%), with the most frequent being Waldenström macroglobulinemia (n = 9, 20%). Forty-one patients (91%) required treatment of CANOMAD. Intravenous immunoglobulins (IVIg) and rituximab-based regimens were the most effective therapies with, respectively, 53% and 52% of partial or better clinical responses. Corticosteroids and immunosuppressive drugs were largely ineffective. Although more studies are warranted to better define the optimal therapeutic sequence, IVIg should be proposed as the standard of care for first-line treatment and rituximab-based regimens for second-line treatment. These compiled data argue for CANOMAD to be included in neurologic monoclonal gammopathy of clinical significance.
Background: Vitamin B12 (B12) has a fundamental role in both central and peripheral nervous system function at all ages. Neurologic manifestations may be the earliest and often the only manifestation ...of B12 deficiency. Mostly because of the poor sensitivity of methods of determination for B12 levels, peripheral neuropathy remains a classical but underdiagnosed complication of B12 deficiency. So the clinical and electrophysiological characteristics of B12-responsive neuropathy are not well known.
Methods: A retrospective study of patients with B12-responsive neuropathy was conducted at our hospital on a 3-year period. The criteria for inclusion were: (a) neuropathy confirmed by the electrophysiological study (nerve conduction study); and (b) improvement of at least 1 point of the total Overall Neuropathy Limitations Scale score after vitamin B12 treatment.
Results: Nine patients were identified. Serum B12 level was low in only four. Four patients had sensorimotor (predominantly sensory) axonal polyneuropathy while five had only sensory neuronopathy. Six improved in less than 1 month after B12 supplementation.
Conclusion: B12-responsive neuropathy is a more heterogeneous group of neuropathy than previously described. B12 deficiency is a cause of peripheral neuropathy and should systematically be ruled out in the clinical setting of idiopathic neuropathy or sensory neuronopathy because of potential reversibility.
Abbreviations: B12: vitamin B12; CMAP: compound muscle action potentials; DRG: dorsal root ganglia; ENMG: electroneuromyography; MCCT: motor central conduction time; MEP: motor evoked potentials; MMA: methylmalonic acid; MMCoAM: L-methylmalonyl-CoenzymeA mutase; ONLS: overall neuropathy limitations scale; SCV: sensory conduction velocities; SNAP: sensory nerve action potentials; SNN: sensory neuronopathy; SSS: SNAP sum score
•Myomex is a randomised, double-blind, placebo-controlled, cross-over study.•It assessed the efficacy and safety of mexiletine in nondystrophic myotonias.•Mexiletine significantly improved stiffness ...over the 18-day treatment period.•Quality of life was also significantly improved.•Mexiletine is efficient and well-tolerated in nondystrophic myotonias.
The MYOMEX study was a multicentre, randomised, double-blind, placebo-controlled, cross-over study aimed to compare the effects of mexiletine vs. placebo in patients with myotonia congenita (MC) and paramyotonia congenita (PC). The primary endpoint was the self-reported score of stiffness severity on a 100 mm visual analogic scale (VAS). Mexiletine treatment started at 200 mg/day and was up-titrated by 200 mg increment each three days to reach a maximum dose of 600 mg/day for total treatment duration of 18 days for each cross-over period. The modified intent-to-treat population included 25 patients (13 with MC and 12 with PC; mean age, 43.0 years; male, 68.0%). The median VAS score for mexiletine was 71.0 at baseline and decreased to 16.0 at the end of the treatment while the score did not change for placebo (81.0 at baseline vs. 78.0 at end of treatment). A mixed effects linear model analysis on ranked absolute changes showed a significant effect of treatment (p < 0.001). The overall score of the Individualized Neuromuscular Quality of Life questionnaire (INQoL) was significantly improved (p < 0.001). No clinically significant adverse events were reported. In conclusion, mexiletine improved stiffness and quality of life in patients with nondystrophic myotonia and was well tolerated.
Monoclonal gammopathy of undeterminated significance is the most common form of plasma cell dyscrasia, usually considered as benign. In rare cases it may have a malignant course, sometimes limited to ...an organ such as peripheral nerves.
We describe clinical, electrophysiological and pathological findings in a patient presenting a immunoglobulin G (IgG) paraproteinemic polyneuropathy clinically mimicking a chronic inflammatory demyelinating polyneuropathy.
Immuno-electron microscopy (immune-EM) demonstrated that the widenings of the myelin lamellae resulted from the infiltration of IgG between a significant number of myelin lamellae (with absence of inflammatory cells in the epineurium, endoneurium, and perineurium, and the lack signs of vasculitis). This patient was finally treated successfully with lenalidomide then mycophenolate mofetil.
In polyneuropathies associated to a monoclonal gammopathy, a nerve biopsy may clinch the diagnosis. Immuno-EM may be required to determine the role of the pathological immunoglobulin in the destruction of the peripheral nerve parenchyma. Diagnosis of such a direct involvement of peripheral nerve can endorse more aggressive treatment of real efficiency.
Charcot-Marie-Tooth type 1A disease (CMT1A) is a rare orphan inherited neuropathy caused by an autosomal dominant duplication of a gene encoding for the structural myelin protein PMP22, which induces ...abnormal Schwann cell differentiation and dysmyelination, eventually leading to axonal suffering then loss and muscle wasting. We favour the idea that diseases can be more efficiently treated when targeting multiple disease-relevant pathways. In CMT1A patients, we therefore tested the potential of PXT3003, a low-dose combination of three already approved compounds (baclofen, naltrexone and sorbitol). Our study conceptually builds on preclinical experiments highlighting a pleiotropic mechanism of action that includes downregulation of PMP22. The primary objective was to assess safety and tolerability of PXT3003. The secondary objective aimed at an exploratory analysis of efficacy of PXT3003 in CMT1A, to be used for designing next clinical development stages (Phase 2b/3).
80 adult patients with mild-to-moderate CMT1A received in double-blind for 1 year Placebo or one of the three increasing doses of PXT3003 tested, in four equal groups. Safety and tolerability were assessed with the incidence of related adverse events. Efficacy was assessed using the Charcot-Marie-Tooth Neuropathy Score (CMTNS) and the Overall Neuropathy Limitations Scale (ONLS) as main endpoints, as well as various clinical and electrophysiological outcomes.
This trial confirmed the safety and tolerability of PXT3003. The highest dose (HD) showed consistent evidence of improvement beyond stabilization. CMTNS and ONLS, with a significant improvement of respectively of 8% (0.4% - 16.2%) and 12.1% (2% - 23.2%) in the HD group versus the pool of all other groups, appear to be the most sensitive clinical endpoints to treatment despite their quasi-stability over one year under Placebo. Patients who did not deteriorate over one year were significantly more frequent in the HD group.
These results confirm that PXT3003 deserves further investigation in adults and could greatly benefit CMT1A-diagnosed children, usually less affected than adults.
EudraCT Number: 2010-023097-40. ClinicalTrials.gov Identifier: NCT01401257. The Committee for Orphan Medicinal Products issued in February 2014 a positive opinion on the application for orphan designation for PXT3003 (EMA/OD/193/13).
Ipilimumab is a fully human monoclonal antibody directed against cytotoxic T-lymphocyte antigen-4 recently approved for the treatment of metastatic melanoma and currently under investigation in the ...adjuvant setting of high-risk stage III melanoma. The blockade of CTLA-4 induces activation of T cells, with an expected increase in the immunological reaction directed to cancer. We report a case of ipilimumab-induced Guillain-Barré syndrome revealed by an occlusive enteric neuropathy. Two weeks after the second dose of ipilimumab, our patient started to complain of abdominal meteorism and nausea. Within a few days, an occlusive syndrome developed. Wall biopsies during colonoscopy revealed a slight edema of the mucosa and a high number of lymphocytic follicles, leading to the diagnosis of ipilimumab-induced immune colitis. A respiratory failure occurred and a neurological deficiency developed rapidly. The diagnosis of polyradiculoneuritis was retained. Despite IV steroids, tacrolimus than plasmatic exchanges, the patient died within a few days because of multivisceral failure. Polyradiculoneuritis is a rare but very severe immune-mediated complication of ipilimumab. Occlusive enteric neuropathy may mimic the digestive symptoms of colitis, which is so frequent under ipilimumab.
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