Comparison of diabetes patients with "demyelinating" diabetic sensorimotor polyneuropathy to those diagnosed with CIDP

Chronic Inflammatory Demyelinating Polyradiculoneuropathy in Association With Concomitant Diseases: Identification and Management

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare, heterogeneous, but treatable autoimmune-mediated peripheral neuropathy characterized by demyelination. CIDP can occur independently or simultaneously with a variety of diseases such as diabetes, monoclonal gammopathy of undetermined significance (MGUS), connective tissue disease, and HIV. It is important to identify CIDP and specific peripheral neuropathies caused by these diseases; this review aims to summarize the CIDP literatures related to diabetes, MGUS, SLE, and HIV, and to be helpful for the management of such patients.

Temporal Dispersion and Duration of the Distal Compound Muscle Action Potential Do Not Distinguish Diabetic Sensorimotor Polyneuropathy From Chronic Inflammatory Demyelinating Polyneuropathy

Objective

To investigate the contribution of duration and temporal dispersion (TD) of the distal compound muscle action potential (CMAP) in discriminating chronic inflammatory demyelinating polyneuropathy (CIDP) from diabetic sensorimotor polyneuropathy (DSP) and from CIDP+DSP.

Methods

We performed a retrospective review of patients diagnosed with CIDP, DSP and CIDP+DSP (responsive to immunotherapy) and examined differences in CMAP duration and TD at baseline.

Results

We included 59 subjects: 17 CIDP, 21 DSP and 21 CIDP+DSP. Of these, 16 (94.1%) CIDP, 18 (85.7%) CIDP+DSP and 1 (4.7%) DSP fulfilled the 2010 EFNS/PNS criteria for definite CIDP. There was no difference in CMAP duration or TD in all nerves (compound outcome) or in individual motor nerves. Patients with CIDP/CIDP+DSP had more conduction blocks, slower conduction velocities and more prolonged F wave latencies than those with DSP.

Conclusion

Measures of CMAP duration and TD were not helpful in distinguishing CIDP, DSP or CIDP+DSP patients; however, parameters such as F-wave latencies, conduction blocks or the number of demyelinating parameters were useful in this separation.

Significance

There are no definite nerve conduction criteria to distinguish patients with CIDP+DSP from DSP alone. Further studies focusing on measures of demyelination may provide stronger evidence to guide treatment decisions in CIDP + DSP patients.

Corneal confocal microscopy differentiates inflammatory from diabetic neuropathy

BACKGROUND

Immune-mediated neuropathies, such as chronic inflammatory demyelinating polyneuropathy (CIDP) are treatable neuropathies. Among individuals with diabetic neuropathy, it remains a challenge to identify those individuals who develop CIDP. Corneal confocal microscopy (CCM) has been shown to detect corneal nerve fiber loss and cellular infiltrates in the sub-basal layer of the cornea. The objective of the study was to determine whether CCM can distinguish diabetic neuropathy from CIDP and whether CCM can detect CIDP in persons with coexisting diabetes.

METHODS

In this multicenter, case-control study, participants with CIDP (n = 55) with (n = 10) and without (n = 45) diabetes; participants with diabetes (n = 58) with (n = 28) and without (n = 30) diabetic neuropathy, and healthy controls (n = 58) underwent CCM. Corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal nerve branch density (CNBD), and dendritic and non-dendritic cell density, with or without nerve fiber contact were quantified.

RESULTS

Dendritic cell density in proximity to corneal nerve fibers was significantly higher in participants with CIDP with and without diabetes compared to participants with diabetic neuropathy and controls. CNFD, CNFL, and CNBD were equally reduced in participants with CIDP, diabetic neuropathy, and CIDP with diabetes.

CONCLUSIONS

An increase in dendritic cell density identifies persons with CIDP. CCM may, therefore, be useful to differentiate inflammatory from non-inflammatory diabetic neuropathy.

Evaluation of the EFNS/PNS diagnostic criteria in a cohort of CIDP patients

Objective

To evaluate the European Federation of Neurological Societies (EFNS)/Peripheral Nerve Society (PNS) diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) in a cohort of patients diagnosed and treated for CIDP in a tertiary university hospital.

Methods

In a monocentric retrospective study of 203 CIDP patients, diagnosed according to expert opinion, we evaluated the EFNS/PNS diagnostic criteria. Clinical course and nerve conduction studies (NCS) over 1 year from first referral were studied. Secondarily, we compared the clinical and paraclinical characteristics, including nerve ultrasound, of patients who failed with those who fulfilled the criteria in order to identify clinically relevant differences.

Results

At 1 year, 182 (89.7%) patients fulfilled the criteria (156/76.9% definite, 22/10.8% probable, and 4/2% possible). Twenty‐one (10.3%) patients did not because the electrodiagnostic criteria remained negative. These still showed signs of demyelination but did not reach the cut‐off values. They also presented typical, albeit less pronounced, multifocal nerve enlargement in ultrasonography. Mean disability at presentation and 1 year after was significantly lower. Most importantly, a relevant proportion of these patients also responded to therapy (6/21 = 28.6% vs. 82/182 = 45.3% of those fulfilling the criteria).

Interpretation

CIDP diagnosis could be established for 89.7% of patients over the course of 1 year using EFNS/PNS criteria. The remaining patients (10.3%) presented with milder disability, less accentuated demyelination, but otherwise similar characteristics and still considerable probability of treatment response. Failure to fulfill diagnostic criteria should not automatically preclude treatment. Nerve ultrasound should be considered as a complementary diagnostic tool to detect signs of inflammation in CIDP.

Randomized, controlled crossover study of IVIg for demyelinating polyneuropathy and diabetes

OBJECTIVE

To determine whether IV immunoglobulin (IVIg) is more effective than placebo at reducing disability in patients with diabetes and demyelinating polyneuropathy features.

METHODS

This is a double-blinded, single-center, randomized, controlled crossover trial of IVIg treatment vs placebo. The primary outcome measure was the mean change in Overall Neuropathy Limitation Scale (ONLS) scores during the IVIg phasecompared with the placebo phase. Secondary outcomes include changes in the Rasch-built Overall Disability Scale, Medical Research Council sum scores, grip strength, electrophysiologic measurements, quality of life, and adverse effects.

RESULTS

Twenty-five subjects were recruited between March 2015 and April 2017. The mean change in ONLS scores was -0.2 points during the IVIg phase and 0.0 points during the placebo phase (p = 0.23). Secondary outcomes did not show significant differences between IVIg and placebo.

CONCLUSIONS

IVIg did not reduce disability, improve strength, or quality of life in patients with demyelinating polyneuropathy features and diabetes after 3 months of treatment in comparison with placebo. Therefore, careful consideration of the primary diagnosis is required before immunomodulatory therapy.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for patients with diabetes and demyelinating polyneuropathy features, IVIg did not significantly reduce disability.

Nerve ultrasound can distinguish chronic inflammatory demyelinating polyneuropathy from demyelinating diabetic sensorimotor polyneuropathy

Diabetic patients with poor glycaemic control can demonstrate demyelinating distal sensorimotor polyneuropathy (D-DSP) on electrophysiology. Distinguishing D-DSP from chronic inflammatory demyelinating polyneuropathy (CIDP) can be challenging. In this study, we investigated the role of nerve ultrasound in differentiating the two neuropathies. Nerve ultrasound findings of D-DSP patients (fulfilling the electrophysiological but not clinical criteria for CIDP) were compared with non-diabetic CIDP patients (fulfilling both criteria). We studied 108 and 95 nerves from 9 D-DSP and 10 CIDP patients respectively. CIDP patients had significantly larger cross-sectional areas of the median nerve at the mid-arm (17.0 ± 12.5 vs 8.7 ± 2.6; p = 0.005), ulnar nerve at the wrist (7.3 ± 3.1 vs 4.1 ± 1.0; p = 0.001), mid forearm (8.8 ± 5.3 vs 5.5 ± 1.5; p = 0.002) and mid-arm (14.5 ± 14.1 vs 7.5 ± 1.9; p = 0.013), and radial nerve at mid forearm (4.1 ± 2.4 vs 1.2 ± 0.4; p < 0.001). In comparison to D-DSP, CIDP patients had markedly larger nerves at the proximal and non-entrapment sites of the upper limbs, suggesting that nerve ultrasound is useful in differentiating the two neuropathies.

Inflammatory Diabetic Neuropathy: Helpful Diagnostic Parameters

OBJECTIVES

Mild inflammatory diabetic neuropathies (IDNs) overlap with diabetic sensorimotor neuropathy (DPN) in clinical presentation and electrophysiological and laboratory tests. This study is to determine whether IDN can be differentiated from DPN by clinical features, electrophysiological, pathological, or laboratory tests.

METHODS

Suspected IDN cases were identified by a subacute onset and progressive sensory or motor neuropathy in patients with diabetes.

RESULTS

IDN occurred earlier in the course of diabetes mellitus and had higher prevalence of limb weakness, walking difficulty, and more severe electrophysiological abnormalities suggesting both demyelination and axonal loss. Sensory nerve biopsies in IDN showed perivascular inflammatory infiltrates, decreased fiber density, increased demyelination, and axonal degeneration. Most patients with IDN improved with immunotherapy.

CONCLUSIONS

Features that favor IDN over DPN are limb weakness, more severe nerve conduction abnormalities, inflammatory infiltrates on nerve biopsy, and a favorable response to immunotherapy. A nerve biopsy can help establish an inflammatory cause.

The dilemma of diabetes in chronic inflammatory demyelinating polyneuropathy

PURPOSE

We reviewed the literature on chronic inflammatory demyelinating polyneuropathy (CIDP) in diabetes mellitus (DM) and explored real-world data on the prevalence and treatment of CIDP within DM.

METHODS

A literature search of Scopus was performed for the terms chronic inflammatory demyelinating polyradiculoneuropathy, chronic inflammatory demyelinating polyneuropathy, CIDP, and prevalence, incidence, epidemiology, or diabetes; peripheral neuropathy and prevalence or diabetes. We also searched through the reference lists of the resulting publications for additional findings that may have been missed. Additional publications on guidelines for the diagnosis of CIDP and diabetic neuropathy were also included. A descriptive analysis of the 2009-2013 PharMetrics Plus™ Database was performed to estimate the prevalence and treatment of CIDP within the DM population.

RESULTS

There is an increasing body of literature suggesting that the prevalence of CIDP tends to be higher in diabetic patients, especially in those of older age. Our real-world data seem to support published findings from the literature. For the total cohort (N=101,321,694), the percent prevalence of CIDP (n=8,173) was 0.008%; DM (n=4,026,740) was 4%. The percent prevalence of CIDP without DM (n=5,986) was 0.006%; CIDP with DM (n=2,187) was 9-fold higher at 0.054%. For patients >50years old, there was a significantly higher percentage of CIDP with DM than CIDP without DM. Approximately 50% of CIDP patients were treated with IVIg, 23%-24% with steroids, 1%-2% with PE, and 20%-23% received no treatment.

CONCLUSIONS

In addition to the growing evidence of higher prevalence of CIDP in DM, our findings reinforce the need for heightened awareness of the association of CIDP and DM.

CIDP variants in diabetes: measuring treatment response with a small nerve fiber test

INTRODUCTION

Chronic inflammatory demyelinating polyneuropathy (CIDP) is eleven times more common among people with diabetes than the general population and is treatable with appropriate immunotherapy. Treatment response is usually measured clinically (symptomatic and functional improvement). We present a case of a patient with type 2 diabetes (T2D) and CIDP whose treatment response was measurable with the Sudoscan sudomotor function test. This test may represent a new objective evaluation of the treatment of CIDP.

CASE DESCRIPTION

The patient is a 60year old male initially referred to our center in August 2012, at which time he was diagnosed with CIDP based on AAN electrodiagnostic criteria (NCS). Autonomic functions were significant for low heart rate variability response to expiration/inspiration (E/I), Valsalva maneuver and the ratio of the RR interval for the 30th to the 15th beat upon standing (1.08, 1.12, 1.05 respectively), and frequency analysis of the total spectral power, the standard deviation of the normal RR intervals (sdNN) and their root mean squared (rmsSD). Sudoscan electrochemical skin conductances (ESC), measuring small nerve fiber function on the palms and soles, were very low: 23 μS in the feet and 32 μS in the hands. After one cycle of intravenous immunoglobulin (IVIG: 6 doses total, 75g each) the patient had no change in symptoms of burning, numbness, shooting pains, and gait impairment. However, E/I, Valsalva, and 30:15 ratios (1.19, 1.36, 1.39 respectively) were improved, as were NCS. Sudoscan scores for feet and hands were unchanged (23 μS and 32 μS). In March 2013, the patient's autonomic functions worsened (E/I, Valsalva, and 30:15 ratios 1.1, 1.07, 1.12 respectively), but feet and hand ESC started to show improvement (35 μS and 52 μS respectively). Azathioprine was started. Eight days after a second cycle of IVIG in January 2014, the patient reported for the first time less burning, shooting pains and tingling. E/I, Valsalva, and 30:15 ratios remained low (1.03, 1.07, and not analyzable, respectively), while foot and hand ESC scores continued to improve (43 μS and 55 μS respectively).

DISCUSSION

CIDP diagnosis and treatment response are difficult in the diabetic patient. We found that NCS and autonomic function tests did not correlate well with clinical status while numerical Sudoscan scores matched closely symptomatic changes. ESC have been found to correlate well with peripheral small fiber function and neuropathic symptoms in DPN. The findings in this patient warrant further investigation of the use of Sudoscan to monitor CIDP response to therapy.

Neuromuscular complications of diabetes mellitus

PURPOSE OF REVIEW

Diabetes mellitus has become a modern global epidemic, with steadily increasing prevalence rates related to lifestyle such that 27% of individuals aged 65 years or older have diabetes mellitus, 95% of whom have type 2. This article reviews the effects of diabetes mellitus on the neuromuscular system.

RECENT FINDINGS

Diabetes mellitus leads to diverse forms of peripheral neuropathy as the major neuromuscular complication. Both focal and diffuse types of neuropathy can develop, with the most common form being diabetic sensorimotor polyneuropathy. Small fibers are damaged early in the development of diabetic sensorimotor polyneuropathy and are not assessed by nerve conduction studies. Small fiber damage occurs even in the prediabetes stage. No disease-modifying therapy for diabetic sensorimotor polyneuropathy is available at this time, but this complication can be limited in patients who have type 1 diabetes mellitus with strict glycemic control; the same outcome is not clearly observed in patients who have type 2 diabetes mellitus. Recently, the evidence base for symptomatic treatments of painful diabetic sensorimotor polyneuropathy underwent systematic review. Effective evidence-based treatments include some anticonvulsants (eg, pregabalin, gabapentin), antidepressants (eg, amitriptyline, duloxetine), opioids (eg, morphine sulfate, oxycodone), capsaicin cream, and transcutaneous electrical nerve stimulation.

SUMMARY

This article reviews the increasing prevalence of diabetes mellitus and diabetic sensorimotor polyneuropathy and discusses recent consensus opinion on the objective confirmation needed for the diagnosis in the clinical research setting. The evidence from clinical trials shows that intensive glycemic control reduces prevalence of diabetic sensorimotor polyneuropathy in patients with type 1 diabetes mellitus, but variable outcomes are observed in patients with type 2 diabetes mellitus. Finally, despite the lack of disease-modifying treatment, effective evidence-based therapy can control painful symptoms of diabetic sensorimotor polyneuropathy.

The characteristics of chronic inflammatory demyelinating polyneuropathy in patients with and without diabetes--an observational study

Introduction

We aimed to determine whether the clinical characteristics and electrodiagnostic classification of nerve injury, and response to treatment differed in patients diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) with and without diabetes.

Methods

CIDP patients with diabetes (CIDP+DM) (n = 67) and without diabetes (CIDP-DM) (n = 67) underwent clinical examination and nerve conduction studies (NCS). CIDP-DM patients were selected using age and gender matching with the existing CIDP+DM cohort. Patients treated with immunotherapies were classified as responders (R) (n = 46) or non-responders (NR) (n = 54) based on clinical response to treatment. The groups were compared using analysis of variance, contingency tables and Kruskal-Wallis analyses.

Results

CIDP+DM subjects had more severe neuropathy based on higher lower limb vibration potential thresholds (VPT)(p = 0.004), higher Toronto Clinical Neuropathy Score (TCNS) (p = 0.0009), more proximal weakness (p = 0.03), more gait abnormality (p = 0.03) and more abnormal NCS. CIDP+DM subjects had more abnormal sural NCS with lower sural sensory nerve action potential amplitudes (2.4±3.0 µV, 6.6±6.0 µV, p<0.0001) and slower sural nerve conduction velocities (38.6±5.4 m/s, 41.0±5.3 m/s, p = 0.04). CIDP-DM subjects were more likely to receive immune therapies (93% vs 57%, p = <0.0001), despite no significant differences in treatment responder rates (p = 0.71). Patients who responded to therapy had shorter duration of CIDP than non-responders (8.0±6.0 y vs 11.9±7.6 y, p = 0.004).

Discussion

The clinical phenotype and electrophysiological profile of CIDP patients differs according to the presence or absence of diabetes. Despite CIDP+DM patients having more severe clinical and electrophysiological neuropathy, they are less likely to receive disease-modifying/specific therapy, yet have similar response rates to treatment as those without diabetes. Specifically, the duration of neuropathy - not diabetes status - was associated with treatment response.