Electrophysiological features of POEMS syndrome and chronic inflammatory demyelinating polyneuropathy

Association of co-existing vitamin B6 and B12 deficiency with polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome: a case report

BACKGROUND

Both vitamin B6 deficiency and vitamin B12 deficiency can present with symptoms that appear like polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, with painful peripheral neuropathy and sensorimotor dysfunction. There are rare reports of an association between vitamin B12 deficiency and POEMS syndrome, and even rarer reports of an association between vitamin B6 deficiency and POEMS syndrome. To our knowledge, this is the first described case with deficiencies in both vitamin B6 and vitamin B12 in association with POEMS syndrome.

CASE PRESENTATION

A man in his 40s presented with fatigue, imbalance, and painful numbness and tingling. Initial evaluation revealed low vitamin B12 level, and he received oral and IV supplementation for one month with an improvement in vitamin B12 levels, but without improvement in symptoms. Further evaluation revealed both a vitamin B6 deficiency and an IgA lambda monoclonal spike, prompting further investigation and an eventual diagnosis of POEMS syndrome. He underwent an autologous stem cell transplant and has had improvement in his symptoms.

CONCLUSIONS

Patients with POEMS syndrome may have symptoms that are difficult to distinguish from deficiencies in vitamin B6 or vitamin B12. Management of POEMS should include screening of vitamin B6 and B12 to ensure other possible associated causes of symptoms are appropriately treated.

Polyneuropathy With Motor Conduction Block in POEMS

INTRODUCTION/AIMS

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a paraneoplastic syndrome due to an underlying plasma cell dyscrasia. Polyneuropathy in POEMS syndrome may present as a subacute or chronic symmetric sensorimotor polyneuropathy, with electrophysiological features suggesting demyelination. Motor conduction block (CB), which is mostly seen in chronic inflammatory demyelinating polyneuropathy (CIDP), is considered an atypical electrophysiological feature in POEMS syndrome. We examined the frequency of motor CB in POEMS syndrome.

METHODS

Patients with POEMS syndrome from the database of our department who had been examined between August 2017 and December 2022 were included in this study. All of the patients' clinical and electrophysiological data were retrospectively collected and analyzed.

RESULTS

We present the data of seven POEMS syndrome patients. Twenty-eight upper extremity motor nerve conduction studies were performed on these patients, and partial CB was detected in seven upper extremity motor nerves (25%) of six of the patients. One patient had motor CB in both the median and ulnar nerves.

DISCUSSION

The distinction between POEMS syndrome and CIDP is important since these conditions require different treatments. Motor CB in POEMS may be more common than has been generally believed. Clinicians should consider this when evaluating patients with demyelinating polyneuropathies and be meticulous in identifying CB. Data from much larger numbers of patients are needed.

Electrodiagnosis of polyneuropathy, organmegaly, endocrinopathy, M-protein, skin changes syndrome patients with peripheral neuropathy and potential-related risk factors

Objectives:

To explore the correlation between classification and electrophysiology of polyneuropathy, organmegaly, endocrinopathy, M-protein, skin changes syndrome (POEMS)-related peripheral neuropathy (PN).

Methods:

We analyzed the data of 30 POEMS patients admitted to Zhongshan Hospital affiliated with Fudan University between February 2017 and February 2023. The degree of PN was determined according to its classification. All three groups of patients underwent neuroelectromyography, and the nerve conduction velocity and amplitude of the three groups were analyzed.

Results:

The compound motor active potentials (CMAP) of the peroneal, tibial, and ulnar nerves decreased significantly with increasing disease grade, and the motor conduction velocity of the peroneal, median, and tibial nerves decreased significantly in grade 3 compared with grade 1 and 2. The action potential of sensory nerves (sensory nerve action potential) and the conduction speed of sensory impulses (sensory conduction velocity (SCV) in the sural nerve in grade 3 were significantly lower than those in grades 1 and 2. Linear regression analysis showed that there was a linear correlation between CMAP of peroneal nerve and vascular endothelial growth factor. The SCV of the ulnar nerve significantly correlated with the course of the disease.

Discussion:

Neuroelectromyography can effectively evaluate the degree of PN in patients with POEMS, providing a reliable reference for further clinical treatment.

New evidence for secondary axonal degeneration in demyelinating neuropathies

Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.

The Noninvasive Diagnostic Value of MRN for CIDP: A Research from Qualitative to Quantitative

STUDY DESIGN

We examined the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and non-CIDP patients who have similar symptoms and difficult to differential diagnosis with CIDP by magnetic resonance neurography to find the difference among them.

OBJECTIVE

To investigate the differential diagnostic value of magnetic resonance neurography (MRN) for CIDP and other peripheral neuropathies.

SUMMARY OF BACKGROUND DATA

Thirty-two consecutive patients with CIDP and 22 non-CIDP patients with symptoms similar to CIDP and difficult to be discriminate were recruited and imaged as a control group between May 2017 and May 2019.

METHODS

In this prospective study, the brachial plexus and lumbosacral plexus of 32 CIDP patients and 22 non-CIDP patients were examined by MRN. The clinical features and the nerve roots cross-sectional area (CSA) of the brachial plexus and lumbosacral plexus were measured.

RESULTS

The CSA of nerve roots of CIDP, Charcot-Marie-Tooth disease type-1 and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome patients were all shown extensive by MRN. The sensitivity of MRN in diagnosing CIDP was 81.25% (26/32), the specificity was 68.18% (15/22), the positive predictive value was 78.79% (26/33), the negative predictive value was 71.43% (15/21), the accuracy was 75.93% (40/54), the misdiagnosis rate was 24.07% (13/54), and the kappa value was 0.498. Receiver operating characteristic analysis showed higher diagnostic accuracy for CIDP with the CSA of the lumbosacral plexus (area under the curve [AUC] = 0.762) and that of the brachial plexus (AUC = 0.762), and the combined of both examinations did not improve the diagnostic efficacy compared with either (AUC = 0.769).

CONCLUSIONS

The nerve roots of CIDP, Charcot-Marie-Tooth disease type-1, and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome were difficult to distinguish by MRN. Atypical CIDP patients had less nerve root injury compared with typical CIDP patients. MRN of either the brachial plexus or the lumbosacral plexus had a high diagnostic accuracy for CIDP, and it is not necessary to perform both parts of the examination.

LEVEL OF EVIDENCE

2.

Clinical characteristics, risk factors, and outcomes of POEMS syndrome

Objective

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin lesions) is a paraneoplastic disorder resulting in severe neurologic disability. Understanding the clinical, laboratory, neurophysiologic, and histopathologic features as well as treatment responses of POEMS will assist in more accurate and timely diagnosis, risk stratification, and effective management.

Methods

This was a retrospective longitudinal cohort study from 1998 to March 2019, with 7,184 person-months of follow-up time. Hospital databases were used to collate presenting features, investigations, therapies, and response.

Results

One hundred patients were included with a median follow-up time of 59 months (range, 1–252). Mean symptom onset to diagnosis was 15 months (range, 1–77), with 54% of patients initially misdiagnosed with chronic inflammatory demyelinating polyneuropathy. Median number of multisystem features at diagnosis was 7. Ninety-six (96%) presented with neuropathy, which was length-dependent in 93 (93%) and painful in 75 (75%). At diagnosis, 35% of patients were wheelchair or bedbound, with median Overall Neuropathy Limitation Score of 6, improving to 3 following treatment (p < 0.05). Five-year survival was 90% and 82% at 10 years, with 5- and 10-year progression-free survival of 65% and 53%. Nontreatment with autologous stem cell transplantation, nonhematologic response, and non–vascular endothelial growth factor response are significant risk factors in multivariate analysis to predict progression or death. Risk factors are incorporated to develop a risk score enabling stratification of high- and low-risk cases.

Conclusions

POEMS syndrome is a rare multisystem condition with delayed diagnosis and poor neurologic function at presentation. Therapy has favorable outcomes. Patients at high risk of death or progression can be identified, which may allow for more active monitoring and influence management.

Clinical and electrophysiological profiles in early recognition of polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome

Background:

The detection of polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome at early stage is challenging for neurologists. Since polyneuropathy could be the first manifestation, it could be misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). The present study aimed to determine the clinical and electrophysiological features of POEMS syndrome to distinguish from CIDP.

Methods:

The data of a group of patients with POEMS (n = 17) and patients with CIDP (n = 17) in Zhongshan Hospital Fudan University from January 2015 to September 2017 were analyzed in this retrospective study. The clinical features, neurological symptoms, and electrophysiological findings were compared between the two groups.

Results:

Clinically, patients with POEMS demonstrated significantly more neuropathic pain in the lower extremities than patients with CIDP (58.8% vs. 11.8%, P = 0.01). Multisystem features like edema, skin change, organomegaly, and thrombocytosis were also pointed towards the diagnosis of POEMS syndrome. Electrophysiologically, terminal latency index (TLI) was significantly higher in patients with POEMS than that in patients with CIDP (median nerve: 0.39 [0.17–0.52] vs. 0.30 (0.07–0.69), Z = –2.413, P = 0.016; ulnar nerve: 0.55 [0.23–0.78] vs. 0.42 [0.12–0.70], Z = –2.034, P = 0.042). Patients with POEMS demonstrated a higher frequency of absent compound muscle action potential of the tibial nerve (52.9% vs. 17.6%, P = 0.031), less conduction block (ulnar nerve: 0 vs. 35.3%, P = 0.018), and less temporal dispersion (median nerve: 17.6% vs. 58.8%, P = 0.032) than CIDP group. The combination of positive serum monoclonal protein and high TLI (if either one or both were present) discriminated POEMS from CIDP with a sensitivity of 94.1% and 47.1% and specificity of 76.5% and 100.0%, respectively.

Conclusions:

POEMS syndrome could be distinguished from CIDP through typical clinical and electrophysiological characteristics in practice. The combination of serum monoclonal protein and high TLI might raise the sensitivity of detecting POEMS syndrome.

POEMS SYNDROME: an Update

POEMS syndrome is a rare, chronic and disabling condition. The causes of this condition remain unknown; however, chronic overproduction of proinflammatory cytokines appears to be a major contributor. Early diagnosis is essential to start treatment before the clinical state of the patient becomes compromised. A complete evaluation of the disease at its onset is critical to the treatment decision. In localized disease, curative doses of radiation (50 Gy) is the recommended therapy. On the other hand, patients with disseminated disease should be given systemic therapy. Treatment-related morbidity can be minimized by an efficient induction therapy that modifies the cytokine status, improving clinical condition and control disease severity before mobilization and transplantation. Patients not suitable for hematopoietic stem cell transplantation (HSCT) are usually treated with alkylator-based therapy. Novel agents may also offer benefits to patients with a poor performance status or renal dysfunction, and induce transplantation eligibility. Given the biological characteristics of POEMS, immunomodulatory effects and the absence of neurotoxicity, lenalidomide appears to be an effective therapy for the treatment of POEMS, both as short induction therapy before PBSCT and in non-transplant eligible patients, as it showed high response rate and durable responses. At present, however, guidelines for the diagnosis and treatment of POEMS are not available and appear advocated.

Electrophysiologic features of POEMS syndrome compared with MGUS-related neuropathy

INTRODUCTION

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome and monoclonal gammopathy of undetermined significance (MGUS) are paraproteinemic disorders that can cause demyelinating polyneuropathy. Herein we assessed the findings of nerve conduction studies (NCS) in patients with POEMS syndrome and MGUS-related neuropathy to determine whether the NCS characteristics can help differentiate between these conditions.

METHODS

We enrolled 24 POEMS and 37 MGUS-related neuropathy patients. NCS parameters, including compound muscle action potential (CMAP), motor conduction velocity (MCV), and terminal latency index (TLI), were evaluated.

RESULTS

Compared with MGUS-related neuropathy patients, POEMS syndrome patients demonstrated a greater reduction in both the upper and lower limb CMAPs and a greater reduction in the median and ulnar MCVs. The TLIs were significantly higher in POEMS patients.

DISCUSSION

NCS can help distinguish POEMS syndrome from MGUS-related neuropathy. Reduced CMAPs, slow MCVs, and high TLIs are indicative of POEMS syndrome rather than MGUS-related neuropathy. Muscle Nerve 56: E73-E77, 2017.

Balance impairments and neuromuscular changes in breast cancer patients with chemotherapy-induced peripheral neuropathy

OBJECTIVE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. Resulting sensory and motor dysfunctions often lead to functional impairments like gait or balance disorders. As the underlying neuromuscular mechanisms are not fully understood, we compared balance performance of CIPN patients with healthy controls (CON) to specify differences responsible for postural instability.

METHODS

20 breast cancer patients with CIPN (PAT) and 16 matched CONs were monitored regarding centre of pressure displacement (COP) and electromyographic activity of M. soleus, gastrocnemius, tibialis anterior, rectus femoris and biceps femoris. We calculated antagonistic co-contraction indices (CCI) and elicited soleus H-reflexes to evaluate changes in the elicitability and sensitivity of spinal reflex circuitry.

RESULTS

PAT's COP displacement was greater than CON's (p=.013) and correlated significantly with the level of CCIs and self-reported CIPN symptoms. PAT revealed prolonged H-wave latency (p=.021), decreased H-reflex elicitability (p=.001), and increased H-reflex sensitivity from bi- to monopedal stance (p=.004).

CONCLUSIONS

We summarise that CIPN causes balance impairments and leads to changes in elicitability and sensitivity of spinal reflex circuitry associated with postural instability. We assume that increased simultaneous antagonistic muscle activation may be used as a safety strategy for joint stiffness to compensate for neuromuscular degradation.

SIGNIFICANCE

Sensorimotor training has the potential to influence neuromuscular mechanisms in order to improve balance performance. Therefore, this training modality should be evaluated as a possible treatment strategy for CIPN.