Chronic inflammatory demyelinating polyradiculoneuropathy: can a diagnosis be made in patients not fulfilling electrodiagnostic criteria?

BACKGROUND AND PURPOSE: The aim was to identify the clinical and diagnostic investigations that may help to support a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients not fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria. METHODS: The data from patients with a clinical diagnosis of CIDP included in a national database were retrospectively reviewed. RESULTS: In all, 535 patients with a diagnosis of CIDP were included. This diagnosis fulfilled the EFNS/PNS criteria in 468 patients (87.2%) (definite in 430, probable in 33, possible in three, while two had chronic immune sensory polyradiculopathy). Sixty-seven patients had a medical history and clinical signs compatible with CIDP but electrodiagnostic studies did not fulfill the EFNS/PNS criteria for CIDP. These patients had similar clinical features and frequency of abnormal supportive criteria for the diagnosis of CIDP compared to patients fulfilling EFNS/PNS criteria. Two or more abnormal supportive criteria were present in 40 (61.2%) patients rising to 54 (80.6%) if a history of a relapsing course as a possible supportive criterion was also included. Increased cerebrospinal fluid proteins and response to immune therapy most frequently helped in supporting the diagnosis of CIDP. Response to therapy was similarly frequent in patients fulfilling or not EFNS/PNS criteria (87.3% vs. 85.9%). CONCLUSIONS: Patients with a clinical diagnosis of CIDP had similar clinical findings, frequency of abnormal supportive criteria and response to therapy compared to patients fulfilling EFNS/PNS criteria. The presence of abnormal supportive criteria may help in supporting the diagnosis of CIDP in patients with a medical history and clinical signs compatible with this diagnosis but non-diagnostic nerve conduction studies.

Treadmill training in patients affected by Charcot-Marie-Tooth neuropathy: results of a multicenter, prospective, randomized, single-blind, controlled study.

BACKGROUND AND PURPOSE: Muscle-strengthening, stretching or proprioceptive treatments may slow symptom progression in Charcot-Marie-Tooth (CMT) neuropathy. The aim of the study was to evaluate safety and efficacy of treadmill training in CMT1A. METHODS: We planned a multicenter, prospective, randomized, single-blind, controlled study. We recruited 53 outpatients affected by CMT1A and randomized them into two treatment groups: one underwent stretching and proprioceptive exercise, whereas the other was additionally treated with treadmill training (TreSPE). Primary outcome measures (OMs) were the walking evaluations and secondary OM was the balance assessment. All participants were assessed at baseline and after 3 and 6 months of treatment. RESULTS: Most patients showed an improvement in at least one OM after 3 months [42/47 (89.4%)] and 6 months [38/40 (95%)] of treatment. No adverse events were reported in either group. CONCLUSIONS: The most important finding was that both stretching and proprioceptive exercise and treadmill training had an objective benefit on patients affected by CMT disease, without causing overwork weakness. We had a low rate of drop out and did not find deterioration in motor performance. Our results also confirm that applying evidence-based medicine methods to rehabilitative research is the correct way to test the efficacy of a treatment.

Fabry disease and enzyme replacement therapy in classic patients with same mutation: different formulations--different outcome?

We describe the results of the multidisciplinary evaluation in patients with Fabry disease and the same genetic mutation and their outcomes using different approved enzyme replacement therapy (ERT). We measured baseline data and serial results of neuropathic pain assessment and renal, cardiac and cerebrovascular functioning. Pain scale showed improvement in all male cases treated with agalsidasa beta. A mild improvement was detected in agalsidasa alfa-treated patients after 1 year with posterior increase. During the agalsidase beta shortage, two male patients were switched to agalsidasa alfa, after 1 year both cases presented an increase in scale values. Renal evolution showed a tendency toward a decrease in proteinuria in patients using agalsidase beta and worsening with agalsidase alfa. We found improvement in two females using agalsidase beta and no changes in the other cases regarding cardiac functioning. Brain magnetic resonance imaging (MRI) showed increase of white matter lesions in four patients. Improvement and stabilization in neuropathic pain, renal and cardiac functioning and brain MRI were found mainly in patients treated with agalsidase beta. Following the reported recommendations on reintroduction of agalsidase beta after the enzyme shortage, we decided to switch all patients to agalsidase beta.

Gastrointestinal involvement in Fabry disease. So important, yet often neglected.

Fabry disease is an X-linked metabolic storage disorder due to the deficiency of lysosomal alpha-galactosidase A which causes accumulation of glycosphingolipids, primarily globotriaosylceramide, throughout the body. Gastrointestinal signs and symptoms-abdominal pain, nausea, diarrhea and diverticular disease--are some of the most frequently reported complaints in patients with Fabry disease but are often neglected. Gastrointestinal symptoms are due to intestinal dysmotility as well as impaired autonomic function, vasculopathy and myopathy. Since 2001, enzyme replacement therapy has been a mainstay in treatment of gastrointestinal symptoms of Fabry disease (FD), resulting in reduced gastrointestinal symptoms. Here, we report on four patients with Fabry disease (FD) who manifested early gastrointestinal involvement.

Novel outcome measures for Charcot-Marie-Tooth disease: validation and reliability of the 6-min walk test and StepWatch(™) Activity Monitor and identification of the walking features related to higher quality of life.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth (CMT) disease is the most common inherited neuropathy, but therapeutic options have been limited to symptom management. Past pharmacological trials have failed, possibly due to insensitive outcome measures (OMs). The aim of the current study was to evaluate the validity and reliability of the 6-min walk test (6MWT) and StepWatch(™) Activity Monitoring (SAM) with other previously validated OMs in CMT disease. METHODS: A prospective multicenter study was performed, consecutively enrolling 168 CMT patients (104 with CMT1A, 27 with CMT1B, 37 with X-linked CMT) from Italian centers specializing in CMT care. RESULTS: Statistical analysis showed that the 6MWT was highly related with all previously used OMs. Some, but not all, SAM parameters were related to commonly used OMs but may provide more information about quality of life. CONCLUSIONS: The current study demonstrated the validity and reliability of the 6MWT and SAM as OMs for CMT. Moreover, SAM provides data that correlate better with quality of life measures, making it useful in future rehabilitation trials.

Nerve conduction velocity in CMT1A: what else can we tell?

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) type 1A is characterized by uniformly reduced nerve conduction velocity (NCV) that is fully penetrant since the first years of life, remains fairly stable through the life and does not correlate with disability whereas compound muscular action potential (CMAP) amplitude does. The aim of the present study was to analyze the large amount of electrophysiological data collected in the ascorbic acid trial in Italy and the UK (CMT-TRIAAL/CMT-TRAUK) and to use these data to gain insights into the pathophysiology of NCV in CMT1A. METHODS: Baseline electrophysiological data from 271 patients were analysed. Electrophysiological recordings were taken from the motor ulnar, median and peroneal nerves and the sensory ulnar nerve. Distal motor latency (DML), motor (MNCV) and sensory (SNCV) nerve conduction velocity, and amplitudes of CMAPs and sensory action potentials were assessed. Electrophysiological findings were correlated with age of patients at examination and the Charcot-Marie-Tooth Examination Score (CMTES). RESULTS: NCV was markedly and uniformly reduced. CMAP amplitudes were overall reduced but more severely in lower limbs. DML decreased and MNCV and SNCV increased with age of the patients, whereas CMAP amplitudes worsened with age and also correlated with CMTES. CONCLUSIONS: This is the largest sample of electrophysiological data obtained so far from CMT1A patients. Axonal degeneration as assessed by means of CMAP amplitude reflected clinical impairment and was consistent with a slowly progressive length-dependent neuropathy. All patients typically had markedly slowed NCV that did, however, slightly increase with age of the patients. The improvement of NCV might depend on myelin thickness remodelling that occurs during the adult life of CMT1A patients.

Evaluation of Bone Mineral Density in Patients with Type 1 Gaucher Disease in Argentina.

The purpose of this study was to evaluate the frequency of osteoporosis (OP) in patients with Gaucher disease (GD) in Argentina. GD patients from 28 centers were consecutively included from April 2012 to 2014. Bone mineral density (BMD) was determined by dual X-ray absorptiometry in the lumbar spine and the femoral neck or the total proximal femur for patients ≥20 yr of age, and by whole-body scan in the lumbar spine in patients <20 yr of age. In children, mineral density was calculated using the chronological age and Z height. OP diagnosis was determined following adult and pediatric official position of the International Society for Clinical Densitometry. A total of 116 patients were included, of which 62 (53.5%) were women. The median age was 25.8 yr. All patients received enzyme replacement therapy, with a median time of 9.4 yr. Normal BMD was found in 89 patients (76.7%), whereas low bone mass (LBM) or osteopenia was found in 15 patients (13%) and OP in 12 patients (10.3%). The analysis of the pediatric population revealed that 4 patients (9.3%) had LBM and 3 (7%) had OP (Z-score ≤ -2 + fractures height-adjusted by Z), whereas in the adult population (n = 73), 11 patients (15%) had LBM or osteopenia and 9 (12.3%) had OP. Bone marrow infiltration and the presence of fractures were significantly correlated with the presence of OP (p = 0.04 and <0.001, respectively). This is the first study in Argentina and in the region describing the frequency of OP or LBM in GD patients treated with imiglucerase using the official position of the International Society for Clinical Densitometry.

Guillain-Barré syndrome following chickenpox: a case series.

Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy, usually triggered by an infectious episode, mostly of viral origin. Varicella zoster virus (VZV) is a rare cause of GBS, mainly in the case of latent infection reactivation. We report on three adult patients who developed GBS following chickenpox, after a short period of latency. They were promptly treated with intravenous immunoglobulin, and the first one with plasma exchange additionally. All the patients experienced almost complete clinical recovery. Our experience suggests that primary VZV infection constitutes a GBS triggering event.

p.L18P: a novel IDUA mutation that causes a distinct attenuated phenotype in mucopolysaccharidosis type I patients.

Mucopolysaccharidosis type I is a rare autosomal recessive disorder caused by deficiency of α-l-iduronidase (IDUA) which leads to a wide spectrum of clinical severity. Here, we describe the case of four male patients who present the previously undescribed p.L18P mutation. Patient 1 (p.L18P/p.L18P) presents, despite multiple joint contractures, an attenuated phenotype. Patient 2 (p.L18P/p.W402X) was diagnosed at 4 years of age with bone dysplasia, coarse facies, limited mobility, claw hands and underwent bilateral carpal tunnel surgery at 6 years of age. Patients 3 and 4 (both p.L18P/p.L18P) are brothers. Patient 3 was diagnosed at 4 years of age, when presented claw hands, lower limb and shoulder pain, restricted articular movement and bilateral carpal tunnel syndrome. Patient 4 was diagnosed at 17 months of age when presented lower limb pain at night, respiratory allergy and repeated upper airways infections. Bioinformatics analysis indicates that p.L18P mutation reduces the signal peptide to 25 amino acids and alters its secondary structure. In conclusion, we report a new IDUA variant that alters the structure of the signal peptide, which likely impairs transport to lysosomes. Moreover, it leads to a distinct attenuated phenotype with mainly bone and cartilage symptoms, without visceromegalies, heart disease, or cognitive impairment.

Contribution of copy number variations in CMT1X: a retrospective study.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease type 1X (CMT1X) is an X-linked dominant hereditary motor-sensory peripheral neuropathy, which results from mutations in the Gap Junction B1 (GJB1) gene. In a few cases, gene deletions have been linked to the disease, but their relative contribution in the pathogenesis of CMT1X has not been assessed yet. Herein a retrospective study to establish the incidence of gene deletions is described. METHODS: Copy number variation analysis was performed by multiplex ligation-dependent probe amplification, whilst the breakpoints were defined by Sanger sequencing. RESULTS: A novel GJB1 deletion was identified in a family presenting with a classical CMT1X phenotype. The rearrangement includes the coding and the regulatory regions of GJB1. CONCLUSIONS: GJB1 deletions appear to be a rare but not insignificant cause of CMT1X and are associated with a typical disease phenotype. Accordingly, patients negative for point mutations whose pedigree and clinical records strongly suggest the possibility of CMT1X should be tested for GJB1 copy number variations.

Responsiveness of clinical outcome measures in Charcot-Marie-Tooth disease.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) is a very slowly progressive neuropathy which makes it difficult to detect disease progression over time and to assess intervention efficacy. Experience from completed clinical trials with ascorbic acid and natural history studies confirm difficulties in detecting such changes. Consequently, sensitive-to-change outcome measures (OMs) are urgently needed. METHODS: The relative responsiveness of clinical scales of the Italian-UK ascorbic acid trial (placebo arm) were assessed by using the standardized response mean (SRM), which is the ratio of the paired scores mean change over time to the standard deviation of the score change (0 is worst responsiveness). RESULTS: Little worsening of OM scores was found over 2 years. In detail, the primary OM of the trial, the CMT Neuropathy Score version 1 (CMTNSv1), showed low responsiveness (SRM 0.13). Some CMTNS items showed slightly greater responsiveness (CMT Examination Score 0.17; CMTNS Signs 0.19). Myometric assessments of handgrip and foot dorsiflexion strength were the most responsive (SRM -0.31 and -0.38, respectively). Amongst the other measures, the nine-hole peg test, which assesses upper limb functioning, showed the best sensitivity to change (SRM 0.28). CONCLUSIONS: Overall these OMs showed low or negligible responsiveness, confirming the need to improve current OMs and to develop novel ones for prognostic and interventional studies. However, handgrip and foot dorsiflexion myometry are worth retaining for future trials as they were the most responsive and are likely to be clinically relevant for patients.

Physician-assessed and patient-reported outcome measures in chemotherapy-induced sensory peripheral neurotoxicity: two sides of the same coin.

BACKGROUND: The different perception and assessment of chemotherapy-induced peripheral neurotoxicity (CIPN) between healthcare providers and patients has not yet been fully addressed, although these two approaches might eventually lead to inconsistent, possibly conflicting interpretation, especially regarding sensory impairment. PATIENTS AND METHODS: A cohort of 281 subjects with stable CIPN was evaluated with the National Cancer Institute-Common Toxicity Criteria (NCI-CTC v. 2.0) sensory scale, the clinical Total Neuropathy Score (TNSc©), the modified Inflammatory Neuropathy Cause and Treatment (INCAT) sensory sumscore (mISS) and the European Organization for Research and Treatment of Cancer CIPN specific self-report questionnaire (EORTC QOL-CIPN20). RESULTS: Patients' probability estimates showed that the EORTC QLQ-CIPN20 sensory score was overall more highly related to the NCI-CTC sensory score. However, the vibration perception item of the TNSc had a higher probability to be scored 0 for EORTC QLQ-CIPN20 scores lower than 35, as vibration score 2 for EORTC QLQ-CIPN20 scores between 35 and 50 and as grade 3 or 4 for EORTC QLQ-CIPN20 scores higher than 50. The linear models showed a significant trend between each mISS item and increasing EORTC QLQ-CIPN20 sensory scores. CONCLUSION: None of the clinical items had a perfect relationship with patients' perception, and most of the discrepancies stood in the intermediate levels of CIPN severity. Our data indicate that to achieve a comprehensive knowledge of CIPN including a reliable assessment of both the severity and the quality of CIPN-related sensory impairment, clinical and PRO measures should be always combined.

Is overwork weakness relevant in Charcot-Marie-Tooth disease?

BACKGROUND: In overwork weakness (OW), muscles are increasingly weakened by exercise, work or daily activities. Although it is a well-established phenomenon in several neuromuscular disorders, it is debated whether it occurs in Charcot-Marie-Tooth disease (CMT). Dominant limb muscles undergo a heavier overload than non-dominant and therefore if OW occurs we would expect them to become weaker. Four previous studies, comparing dominant and non-dominant hand strength in CMT series employing manual testing or myometry, gave contradictory results. Moreover, none of them examined the behaviour of lower limb muscles. METHODS: We tested the OW hypothesis in 271 CMT1A adult patients by comparing bilateral intrinsic hand and leg muscle strength with manual testing as well as manual dexterity. RESULTS: We found no significant difference between sides for the strength of first dorsal interosseous, abductor pollicis brevis, anterior tibialis and triceps surae. Dominant side muscles did not become weaker than non-dominant with increasing age and disease severity (assessed with the CMT Neuropathy Score); in fact, the dominant triceps surae was slightly stronger than the non-dominant with increasing age and disease severity. DISCUSSION: Our data does not support the OW hypothesis and the consequent harmful effect of exercise in patients with CMT1A. Physical activity should be encouraged, and rehabilitation remains the most effective treatment for CMT patients.

The chemotherapy-induced peripheral neuropathy outcome measures standardization study: from consensus to the first validity and reliability findings.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and dose-limiting complication of cancer treatment. Thus far, the impact of CIPN has not been studied in a systematic clinimetric manner. The objective of the study was to select outcome measures for CIPN evaluation and to establish their validity and reproducibility in a cross-sectional multicenter study. PATIENTS AND METHODS: After literature review and a consensus meeting among experts, face/content validity were obtained for the following selected scales: the National Cancer Institute-Common Toxicity Criteria (NCI-CTC), the Total Neuropathy Score clinical version (TNSc), the modified Inflammatory Neuropathy Cause and Treatment (INCAT) group sensory sumscore (mISS), the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, and CIPN20 quality-of-life measures. A total of 281 patients with stable CIPN were examined. Validity (correlation) and reliability studies were carried out. RESULTS: Good inter-/intra-observer scores were obtained for the TNSc, mISS, and NCI-CTC sensory/motor subscales. Test-retest values were also good for the EORTC QLQ-C30 and CIPN20. Acceptable validity scores were obtained through the correlation among the measures. CONCLUSION: Good validity and reliability scores were demonstrated for the set of selected impairment and quality-of-life outcome measures in CIPN. Future studies are planned to investigate the responsiveness aspects of these measures.

Abruptio placentae in cynomolgus macaques (Macaca fascicularis): male bias.

BACKGROUND: Abruptio placentae is a serious problem with a high rate of maternal and fetal mortality and documented sexual dimorphism in reoccurrence. Macaca fascicularis is a well-described reproductive model; however, there are no data available regarding sexual dimorphism in abruptio placentae in these species. METHODS: A retrospective study of pathology and medical records in a large colony of M. fascicularis was performed. Placental specimens were analyzed. RESULTS: The incidence of placenta abruptio in the colony was 15.7/1000 births. In the abruptio placentae group, male fetuses had lower placental disk length and increased femur length compared with female fetuses. The feto-pacental ratio and fetal weight were lower in the male fetuses in the abruption group compared with those in the stillbirth group without abruption placentae. CONCLUSION: This is the first documentation of male bias in placental and fetal development in abruptio placentae in non-human primates.

Consistence and discrepancy of neuropathic pain screening tools DN4 and ID-Pain.

Pain is a subjective condition that cannot be objectively measured; for this reason, self patient-perspective is crucial. Recently, several screening tools to discriminate between nociceptive and neuropathic pain have been developed. We aimed at assessing the consistence and discrepancy of two widely used screening tools, The Douleur Neuropathique 4 (DN4) and the 6-item questionnaire (ID-Pain), by comparing their ability in discriminating neuropathic from nociceptive pain. DN4 and ID-Pain were administered to 392 Italian patients attending 16 outpatient services for peripheral nerve diseases. Based on medical history, clinical findings and diagnostic tools, patients were divided into two groups (neuropathic and nociceptive). Globally, ID-Pain identified neuropathic pain in 60 % of patients (38 % probable, 22 % likely). Interestingly also DN4 diagnosed neuropathic pain in 60 % of cases. A discrepancy was observed in 16 % of cases. DN4 and ID-Pain resulted to be highly interrelated in the identification of neuropathic pain. Sensitivity of DN4 was 82 % and specificity was 81 %, while ID-Pain (considering both probable and likely groups) showed sensitivity 78 % and specificity 74 %. Reliable screening tools for neuropathic pain are well related between them; hence, they are available for researchers and clinicians who may choose the most appropriate for their activity. Since the gold standard for the diagnosis and treatment of neuropathic pain cannot do without a neurological evaluation, perhaps DN4, that includes physician objective measures, may help reducing the percentage of dubious cases. Conversely, when needing a more agile tool (not needing a physician) ID-Pain may be adopted.

Charcot-Marie-Tooth type 4B is caused by mutations in the gene encoding myotubularin-related protein-2.

A gene mutated in Charcot-Marie-Tooth disease type 4B (CMT4B), an autosomal recessive demyelinating neuropathy with myelin outfoldings, has been mapped on chromosome 11q22. Using a positional-cloning strategy, we identified in unrelated CMT4B patients mutations occurring in the gene MTMR2, encoding myotubularin-related protein-2, a dual specificity phosphatase (DSP).

Expert recommendations for the laboratory diagnosis of MPS VI.

Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease caused by a deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B, ASB). This enzyme is required for the degradation of dermatan sulfate. In its absence, dermatan sulfate accumulates in cells and is excreted in large quantities in urine. Specific therapeutic intervention is available; however, accurate and timely diagnosis is crucial for maximal benefit. To better understand the current practices for diagnosis and to establish diagnostic guidelines, an international MPS VI laboratory diagnostics scientific summit was held in February of 2011 in Miami, Florida. The various steps in the diagnosis of MPS VI were discussed including urinary glycosaminoglycan (uGAG) analysis, enzyme activity analysis, and molecular analysis. The following conclusions were reached. Dilute urine samples pose a significant problem for uGAG analysis and MPS VI patients can be missed by quantitative uGAG testing alone as dermatan sulfate may not always be excreted in large quantities. Enzyme activity analysis is universally acknowledged as a key component of diagnosis; however, several caveats must be considered and the appropriate use of reference enzymes is essential. Molecular analysis supports enzyme activity test results and is essential for carrier testing, subsequent genetic counseling, and prenatal testing. Overall the expert panel recommends caution in the use of uGAG screening alone to rule out or confirm the diagnosis of MPS VI and acknowledges enzyme activity analysis as a critical component of diagnosis. Measurement of another sulfatase enzyme to exclude multiple sulfatase deficiency was recommended prior to the initiation of therapy. When feasible, the use of molecular testing as part of the diagnosis is encouraged. A diagnostic algorithm for MPS VI is provided.

Rituximab in patients with chronic inflammatory demyelinating polyradiculoneuropathy: a report of 13 cases and review of the literature.

BACKGROUND: A few case reports have shown controversial results of rituximab efficacy in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). OBJECTIVE: To analyse the efficacy of rituximab in a large CIDP cohort. METHODS: A retrospective, observational and multicentre study on the use of rituximab in CIDP. 13 Italian CIDP patients were treated with rituximab after the partial or complete lack of efficacy of conventional therapies. Eight patients had co-occurring haematological diseases. Patients who improved by at least two points in standard clinical scales, or who reduced or discontinued the pre-rituximab therapies, were considered as responders. RESULTS: Nine patients (seven with haematological diseases) responded to rituximab: six of them, who were non-responders to conventional therapies, improved clinically, and the other three maintained the improvement that they usually achieved with intravenous immunoglobulin or plasma exchange. Significantly associated with shorter disease duration, rituximab responses started after a median period of 2.0 months (range, 1-6) and lasted for a median period of 1 year (range, 1-5). CONCLUSIONS: Rituximab seems to be a promising therapeutic choice when it targets both CIDP and co-occurring haematological diseases. Timely post-onset administration of rituximab seems to be associated with better responses.