Comparing the NIS vs. MRC and INCAT sensory scale through Rasch analyses

Long-term outcomes of paediatric Guillain-Barré syndrome

AIM

To study long-term sequelae in children with Guillain-Barré syndrome (GBS).

METHOD

This was a prospective observational study with children from two French tertiary centres. Data were from clinical and several standardized scales or questionnaires.

RESULTS

Fifty-one patients were included with a median follow-up of 6 years 4 months (range 3-20 years) after the acute phase. The sequelae rate was 67% (95% confidence interval [CI] 53-78) and did not vary with time. Most children had minor sequelae (Guillain-Barré Syndrome Disability Score [GBSDS] = 1); only one was unable to run (GBSDS = 2). The most frequent complaints were paraesthesia (43%), pain (35%), and fatigue (31%). The neurological examination was abnormal in 18% of children, autonomy was compromised in 14%, and symptoms of depression occurred in 34%. The factors associated with late-onset sequelae were correlated with severity during the initial phase (i.e. initial GBSDS >4, odds ratio 6.6, 95% CI 1.8-33; p = 0.009). The predictive factors of more severe late-onset conditions were initial severity (p = 0.002) and sex (female patients; p = 0.01).

INTERPRETATION

Two-thirds of children with GBS had late-onset sequelae following an episode, often minor, but sometimes with continuing effects on their everyday lives. Particularly affected were those who had severe GBS during the acute phase and who lost the ability to walk.

WHAT THIS PAPER ADDS

Two-thirds of children with Guillain-Barré syndrome (GBS) had persistent sequelae. Sequelae were often minor, but daily repercussions of them were sometimes serious. Sequelae were significantly associated with severe GBS during the acute phase.

Chronic inflammatory demyelinating polyradiculoneuropathy: Diagnostic problems in clinical practice in Serbia

Making diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is challenging since it can mimic a multitude of disorders, and is misdiagnosed in at least 50% of cases. We sought to determine the frequency of CIDP misdiagnosis in clinical practice in Serbia, to uncover CIDP mimics, and to identify factors that may aid in CIDP diagnosis. Our longitudinal retrospective cohort study included 86 eligible adult patients referred to the Neurology Clinic, University Clinical Centre of Serbia, with a diagnosis of CIDP. We also included 15 patients referred to us with different diagnoses that ended up having CIDP as their final diagnosis. Exactly half of patients referred as CIDP failed to meet the established diagnostic criteria (non-CIDP) and were given an alternative diagnosis at the first hospitalization. At the 1-year follow-up, the diagnosis was further revised in four subjects. Confirmed CIDP patients usually had their initial diagnosis based on the nerve conduction studies (NCS), a typical presentation with symmetrical involvement of all four limbs, as well as higher frequencies of elevated protein levels and albuminocytologic dissociation in the cerebrospinal fluid (CSF). CIDP patients also responded better to immune therapy. We found that 52% of the patients initially referred to our Clinic as CIDP were given other diagnoses after a 1-year follow-up. Out of all CIDP cases, 27% had been unrecognized prior to referral to our Center. Utilization of clear and objective indicators - conclusive NCS, improvement on therapy, and elevated CSF proteins may provide greater certainty in diagnosing CIDP.

Efficacy of rituximab in anti-myelin-associated glycoprotein demyelinating polyneuropathy: Clinical, hematological and neurophysiological correlations during 2 years of follow-up

BACKGROUND AND PURPOSE

We evaluated the clinical and neurophysiological efficacy of rituximab (RTX) in a neurophysiologically homogeneous group of patients with monoclonal gammopathy and immunoglobulin M (IgM) anti-myelin-associated glycoprotein antibody (anti-MAG) demyelinating polyneuropathy.

METHODS

Twenty three anti-MAG-positive polyneuropathic patients were prospectively evaluated before and for 2 years after treatment with RTX 375 mg/m² . The Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale (INCAT-ds), modified INCAT sensory score (mISS), Medical Research Council sum score, Patients' Global Impression of Change scale were used, IgM levels were assessed and extensive electrophysiological examinations were performed before (T0) and 1 year (T1) and 2 years (T2) after RTX treatment.

RESULTS

At T1 and T2 there was a significant reduction from T0 both in mISS and in INCAT-ds, with a p value < 0.001 in the inferential Friedman's test overall analysis. Ulnar nerve Terminal Latency Index and distal motor latency significantly changed from T0 to T1 and in the overall analysis (p = 0.001 and p = 0.002), and ulnar nerve sensory nerve action potential (SNAP) amplitude was significantly increased at T2 from T1, with a p value < 0.001 in the overall analysis. Analysis of the receiver-operating characteristic curves showed that a 41.8% increase in SNAP amplitude in the ulnar nerve at T2 from T0 was a fair predictor of a mISS reduction of ≥2 points (area under the curve 0.85; p = 0.005; sensitivity: 90.9%, specificity: 83.3%).

CONCLUSIONS

This study suggests that RTX is effective in patients with clinically active demyelinating anti-MAG neuropathy over 2 years of follow-up, and that some neurophysiological variables might be useful for monitoring this efficacy.

Immunochemotherapy versus rituximab in anti-myelin-associated glycoprotein neuropathy: A report of 64 patients

Monoclonal immunoglobulin M (IgM) anti-myelin-associated glycoprotein (MAG) neuropathy is a rare disabling condition, most commonly treated with rituximab monotherapy (R), which leads to neurological improvement in only 30%-50% of patients. The combination of rituximab plus chemotherapy has been proven to improve the level of responses. We studied the outcomes of anti-MAG neuropathy patients treated either by R, or by immunochemotherapy (ICT) in our centre, focusing on the incidence of the first neurological response evaluated by the modified Rankin scale (mRS). From 2011 to 2018, 64 patients were studied: 34 were treated with R and 30 with ICT. According to our treatment decision-making process, the median mRS was higher in the ICT group (mRS 2) than in the R group (mRS 1). At one year, improvements of the mRS rates were 46% and 18% in the ICT and R groups of patients respectively, with median times to response of eight and 13 months (p = 0.023). Adverse effects were higher in the ICT group: 62% vs 15% (p ˂ 0.01), all grades included. One secondary acute leukaemia occurred five years after treatment with ICT. In conclusion, ICT may be used as a valid option for patients with rapidly progressive and/or severe anti-MAG neuropathy symptoms.

Underdiagnosis and diagnostic delay in chronic inflammatory demyelinating polyneuropathy

BACKGROUND

The frequency and causes of underdiagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) are uncertain. We aimed to assess the frequency and electroclinical features of pre-referral CIDP underdiagnosis and the duration of delay prior to diagnosis and treatment initiation in a tertiary specialist clinic.

METHODS

We retrospectively investigated 60 consecutive patients attending our Inflammatory Neuropathy Service, between 2015 and 2019, with a final diagnosis of treatment-responsive definite/probable CIDP. We reviewed the clinical and electrophysiological data in light of European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) guidelines and determined the frequency, causes and delay in diagnosis of CIDP.

RESULTS

An initial alternative diagnosis to that of CIDP had been made in 68.3% (41/60) of patients. The commonest alternative diagnosis was of Guillain-Barré syndrome (GBS) in 23.3% (14/60) patients. Non-GBS underdiagnoses (27/60; 45%) mainly consisted of genetic neuropathy (8/27; 29.6%), diabetic neuropathy (5/27; 18.5%) and chronic idiopathic axonal polyneuropathy (4/27; 14.8%). Non-GBS underdiagnoses were predominantly due to non-recognition of proximal weakness (70.4%), multifocal deficits (18.5%) or proprioceptive loss (7.4%). Electrophysiological misinterpretation was contributory to pre-referral non-GBS underdiagnoses of CIDP in 85% of patients. Mean diagnostic delay in patients with non-GBS underdiagnoses of CIDP was of 21.3 months (range 2-132 months).

CONCLUSION

Underdiagnosis of CIDP is frequent and may lead to significant diagnostic and treatment delay. We suggest that lack of comprehensive and precise attention to typical electroclinical features of CIDP and its diagnostic criteria at the time of initial evaluation are equally contributory to underdiagnoses.

Psychometric longitudinal evaluation of the Chronic Acquired Polyneuropathy Patient-Reported Index (CAPPRI) in patients with chronic inflammatory demyelinating polyneuropathy

BACKGROUND

We studied the performance of a 15-item, health-related quality-of-life polyneuropathy scale in a longitudinal study of patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

Sixty-one patients with CIDP completed the Chronic Acquired Polyneuropathy Patient-Reported Index (CAPPRI) scale and Patient Impression of Change (PIC) at baseline and follow-up visits. Clinicians completed Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores at baseline and follow-up visits. Conventional and modern psychometric analyses were performed on the completed forms.

RESULTS

CAPPRI was psychometrically stable between visits without significant difference in response pattern between visits 1 and 2 (paired t-test P = .72). There was strong correlation between changes in INCAT and changes in CAPPRI scores between two visits (rho = 0.6, P < .001). In addition, we showed robust CAPPRI effect sizes between PIC categories.

CONCLUSIONS

We demonstrated psychometric stability and construct longitudinal validity of CAPPRI.

Quality of life in patients with polyneuropathy associated with different types of monoclonal gammopathy of undetermined significance

Polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS-PNP) has a chronic and slowly progressive course but can lead to significant disability and reduced quality of life (QoL). The aim of this study was to analyze QoL in MGUS-PNP patients and to determine its predictors. Our study included 51 patients diagnosed with MGUS-PNP (23.5% with IgM, 66.7% IgG or IgA, 7.8% undetermined paraprotein, 2.0% light chains). QoL was assessed using the SF-36 questionnaire. The Medical Research Council Sum Score (MRC-SS), INCAT disability and sensory scores, ataxia score, Krupp's Fatigue Severity Scale and Beck's Depression Inventory were also used. Total SF-36 score was 50.0 ± 21.4 and no difference was observed between IgM and IgG/IgA MGUS-PNP. Physical composite score was worse than mental (44.4 ± 21.4 vs. 54.5 ± 20.9). Following factors showed correlation with SF-36 total score in univariate analysis: INCAT disability score, MRC-SS, INCAT sensory score, level of ataxia, fatigue and depression (p < 0.01). Significant predictors of worse SF-36 total score in our MGUS-PNP patients were depression (β = - 0.46, p < 0.01), fatigue (β = - 0.32, p < 0.01) and INCAT disability score (β = - 0.27, p < 0.01). QoL in MGUS-PNP is equally affected in patients with different types of paraprotein. MGUS-PNP patients with more severe functional disability, fatigue and depression need special attention of clinicians since they could be at higher risk to have worse QoL. This should be taken into account when treating subjects with MGUS-PNP.

Nerve ultrasound for diagnosing chronic inflammatory neuropathy: A multicenter validation study

OBJECTIVE

To validate the diagnostic accuracy of a previously described short sonographic protocol to identify chronic inflammatory neuropathy (CIN), including chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis Sumner syndrome, and multifocal motor neuropathy (MMN), and to determine the added value of nerve ultrasound to detect treatment-responsive patients compared to nerve conduction studies (NCS) in a prospective multicenter study.

METHODS

We included 100 consecutive patients clinically suspected of CIN in 3 centers. The study protocol consisted of neurologic examination, laboratory tests, NCS, and nerve ultrasound. We validated a short sonographic protocol (median nerve at forearm, upper arm, and C5 nerve root) and determined its diagnostic accuracy using the European Federation of Neurological Societies/Peripheral Nerve Society criteria of CIDP/MMN (reference standard). In addition, to determine the added value of nerve ultrasound in detecting treatment-responsive patients, we used previously published diagnostic criteria based on clinical, NCS, and sonographic findings and treatment response (alternative reference standard).

RESULTS

Sensitivity and specificity of the sonographic protocol for CIN according to the reference standard were 87.4% and 67.3%, respectively. Sensitivity and specificity of this protocol according to the alternative reference standard were 84.6% and 72.8%, respectively, and of NCS 76.1% and 93.4%. With addition of nerve ultrasound, 44 diagnoses of CIN were established compared to 33 diagnoses with NCS alone.

CONCLUSIONS

A short sonographic protocol shows high diagnostic accuracy for detecting CIN. Nerve ultrasound is able to detect up to 25% more patients who respond to treatment.

CLASSIFICATION OF EVIDENCE

This multicenter study provides Class IV evidence that nerve ultrasound improves diagnosis of CIN.

Nerve ultrasound improves detection of treatment-responsive chronic inflammatory neuropathies

OBJECTIVE

To examine the diagnostic accuracy of nerve ultrasound in a prospective cohort of consecutive patients with a clinical suspicion of chronic inflammatory neuropathies, including chronic inflammatory demyelinating polyneuropathy, Lewis-Sumner syndrome, and multifocal motor neuropathy, and to determine the added value in the detection of treatment-responsive patients.

METHODS

Between February 2015 and July 2018, we included 100 consecutive incident patients with a clinical suspicion of chronic inflammatory neuropathy. All patients underwent nerve ultrasound, extensive standardized nerve conduction studies (NCS), and other relevant diagnostic investigations. We evaluated treatment response using predefined criteria. A diagnosis of chronic inflammatory neuropathy was established when NCS were abnormal (fulfilling criteria of demyelination of the European Federation of Neurological Societies/Peripheral Nerve Society) or when the degree of nerve enlargement detected by sonography was compatible with chronic inflammatory neuropathy and there was response to treatment.

RESULTS

A diagnosis of chronic inflammatory neuropathy was established in 38 patients. Sensitivity and specificity of nerve ultrasound and NCS were 97.4% and 69.4% and 78.9% and 93.5%, respectively. The added value of nerve ultrasound in detection of treatment-responsive chronic inflammatory neuropathy was 21.1% compared to NCS alone.

CONCLUSIONS

Nerve ultrasound and NCS are complementary techniques with superior sensitivity in the former and specificity in the latter. Addition of nerve ultrasound significantly improves the detection of chronic inflammatory neuropathies. Therefore, it deserves a prominent place in the diagnostic workup of chronic inflammatory neuropathies.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that nerve ultrasound is an accurate diagnostic tool to detect chronic inflammatory neuropathies.

Development of grading scales of pedal sensory loss using Mokken scale analysis on the Rotterdam Diabetic Foot Study Test Battery data

INTRODUCTION

Loss of sensation due to diabetes-related neuropathy often leads to diabetic foot ulceration. Several test instruments are used to assess sensation, such as static and moving 2-point discrimination (S2PD, M2PD), monofilaments, and tuning forks.

METHODS

Mokken scale analysis was applied to the Rotterdam Diabetic Foot Study data to select hierarchies of tests to construct measurement scales.

RESULTS

We developed 39-item and 31-item scales to measure loss of sensation for research purposes and a 13-item scale for clinical practice. All instruments were strongly scalable and reliable. The 39 items can be classified into 5 hierarchically ordered core clusters: S2PD, M2PD, vibration sense, monofilaments, and prior ulcer or amputation.

DISCUSSION

Guided by the presented scales, clinicians may better classify the grade of sensory loss in diabetic patients' feet. Thus, a more personalized approach concerning individual recommendations, intervention strategies, and patient information may be applied.

One-year follow-up study of neuropathic pain in chronic inflammatory demyelinating polyradiculoneuropathy

We sought to gather information about frequency and features of neuropathic pain (NeP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and to investigate course of NeP during 1-year follow-up. Study included 105 patients diagnosed with CIDP. Patients with diabetes (N = 26) were excluded. NeP was diagnosed by the official guidelines and painDETECT questionnaire (PD-Q). Medical Research Council Sum Score (MRC-SS), INCAT disability and sensory scores, and Beck Depression Inventory were also measured. PD-Q showed presence of NeP in 16 (20%) of 79 CIDP patients and their mean pain was moderate (5.1 ± 3.0 of 10). Diagnostic delay in CIDP patients with NeP was prolonged compared to CIDP patients without NeP (21 ± 28 vs 9 ± 12 months, P < .05). Slowly progressive course of the disease was more frequent in patients with NeP (81% vs 52%, P < .05). Patients with NeP had worse INCAT sensory score (P < .01), INCAT disability score (P < .05), MRC-SS, as well as worse disease outcome at time of testing (P < .05). Depression was more common in patients with NeP (69% vs 17%, P < .01). During 1-year follow-up, majority of our CIDP patients had good control of NeP with gabapentinoids or amitriptyline. NeP was common in our cohort of non-diabetic CIDP patients. It was associated with worse functional disability, worse sensory deficit, and depression. Special attention should be paid to CIDP patients with NeP because they request additional symptomatic therapy that appeared efficacious in our cohort.

Rasch model-based testing of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy (QLQ-CIPN20) using Alliance for Clinical Trials in Oncology (Alliance) A151408 study data

PURPOSE

To test the psychometric properties of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy (QLQ-CIPN20) using Rasch-based methods.

METHODS

A secondary data analysis was performed using pooled QLQ-CIPN20 data from patients (N = 1008) who had participated in any of four multi-site chemotherapy-induced peripheral neuropathy (CIPN) treatment and prevention trials. QLQ-CIPN20 responses were evaluated using a polytomous Rasch partial credit model. Data were assessed for person-item fit using the chi-square statistic, item scaling based on response proportions, threshold ordering using item characteristic curves and logit threshold locations, differential item response (DIF) (i.e., response bias) using likelihood ratio tests, and unidimensionality using cluster analysis.

RESULTS

A statistically significant chi-square test indicated poor fit of the observed to the expected responses. More than 70% of the respondents reported a complete absence of six symptoms, reflecting significant floor effects and poor item scaling. Disordered/non-ordinal or narrow response thresholds were found for 11 of the 20 items. Item responses were significantly different by gender (p < 0.0001) and chemotherapy type (p < 0.0001). Cluster analysis findings suggest that the QLQ-CIPN20 is a unidimensional scale due to the absence of item clusters.

CONCLUSIONS

Rasch model testing revealed psychometric weaknesses that could be addressed by revising the QLQ-CIPN20's problematic items and response options. Alternatively, perhaps the new gold standard CIPN measurement approach in future intervention trials should involve use of only the best items, which would also allow comparisons across previous trials that utilized the QLQ-CIPN20.

Grading the loss of sensation in diabetic patients: A psychometric evaluation of the rotterdam diabetic foot study test battery

Introduction: Static‐ and moving 2‐point discrimination (S2PD, M2PD), 10‐g monofilaments‐ and tuning fork are validated outcome measures of clinical manifestations of diabetes‐related neuropathy. No modern statistical techniques have been used to investigate how well these instruments combine to measure sensory loss. Methods: To grade sensory loss at the feet, we fitted parametric forms of Item Response Theory models to the data of these instruments. Results: The fit statistics indicate that the loss of sensation is gradable, with readily available instruments. S2PD and M2PD are lost first, followed by vibration sense, the 10‐g monofilament and the ability to feel a cold stimulus. Conclusions: This test battery appears to provide sound measurement properties in a group of diabetic patients with diverse amounts of sensory loss. This approach may be used in clinical practice to grade sensory loss reliably and quickly, with instruments that are easy to use. Muscle Nerve58: 559–565, 2018

Neuromuscular disease-specific questionnaire to assess quality of life in patients with chronic inflammatory demyelinating polyradiculoneuropathy

To date, generic questionnaires have been used to investigate quality of life (QoL) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Although these measures are very useful, they are not usually precise enough to measure all specific characteristics of the disease. Our aim was to investigate QoL using the neuromuscular disease-specific questionnaire (individualized neuromuscular quality of life, INQoL) in a large cohort of patients with CIDP. Our study comprised 106 patients diagnosed with CIDP. INQoL questionnaire, Medical Research Council (MRC) sum score, Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Visual Analogue Pain Scale, Beck Depression Inventory, and Krupp's Fatigue Severity Scale were used in our study. Physical domains of INQoL were more affected than mental, and the overall score was 57 ± 25. Significant predictors of higher INQoL score in our patients with CIDP were severe fatigue (β = 0.35, p < 0.01), higher INCAT disability score at time of testing (β = 0.29, p < 0.01), and being unemployed/retired (β = 0.22, p < 0.05). QoL was reduced in our cohort of CIDP patients, which was more pronounced in physical segments. Patients with fatigue, more severe disability, and unemployed/retired need special attention of neurologists because they could be at greater risk to have worse QoL.

What is new in 2015 in dysimmune neuropathies?

This review discusses and summarizes the concept of nodopathies, the diagnostic features, investigations, pathophysiology, and treatment options of chronic inflammatory demyelinating polyradiculoneuropathy, and gives updates on other inflammatory and dysimmune neuropathies such as Guillain-Barré syndrome, sensory neuronopathies, small-fiber-predominant ganglionitis, POEMS syndrome, neuropathies associated with IgM monoclonal gammopathy and multifocal motor neuropathy. This field of research has contributed to the antigenic characterization of the peripheral motor and sensory functional systems, as well as helping to define immune neuropathic syndromes with widely different clinical presentation, prognosis and response to therapy.

Assessment scales for the diagnosis of polyneuropathy

Epidemiological studies that investigate the occurrence and determinants of chronic length-dependent polyneuropathy are scarce. Population-based studies on polyneuropathy require a valid and reliable screening protocol with both good sensitivity and specificity. Several questionnaires and scoring scales have been developed for the detection of polyneuropathy, grading the severity of the disease, or evaluating the clinical course during follow-up. This review summarizes the aims and content of existing diagnostic polyneuropathy screening tools in order to help future studies decide which scale to use for screening in specific situations. We searched the PubMed database and identified 27 scales, 13 are based on symptoms alone, 8 on neurological signs alone, and 6 on a combination of symptoms and signs. Scales that combine questions concerning symptoms and a neurological examination with a focus on sensory alterations seem to have the best discriminatory power. However, all scoring scales were developed for and investigated in prespecified patient populations. Therefore, the generalizability of specific findings to the general population may be limited. We also discuss other limitations of existing scales. Future studies are required to determine which clinimetrically well-developed scales are preferred for use in population-based studies.