Preserved autonomic function in patients with POEMS syndrome

Paraproteinemia and neuropathy

Paraproteinemia is associated with different peripheral neuropathies. The major causes of neuropathy correlated with paraproteinemia are the deposition of immunoglobulin in the myelin, represented by anti-myelin-associated glycoprotein (MAG) neuropathy; deposition of immunoglobulin or its fragment in the interstitium, represented by immunoglobulin light chain amyloidosis (AL amyloidosis); and paraneoplastic mechanisms that cannot be solely attributed to the deposition of immunoglobulin or its fragment, represented by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin change (POEMS) syndrome. Patients with anti-MAG neuropathy and POEMS syndrome present with slowing of nerve conduction parameters. This characteristic fulfills the electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) defined by the European Academy of Neurology and Peripheral Nerve Society (EAN/PNS). Although direct damage caused by the deposition of amyloid can induce axonal damage in AL amyloidosis, some patients with this condition have features fulfilling the EAN/PNS electrodiagnostic criteria for CIDP. Conventional immunotherapies for CIDP, such as steroids, intravenous immunoglobulin, and plasma exchange, offer no or only minimal-to-modest benefit. Although rituximab can reduce the level of circulating autoantibodies, it may only be effective in some patients with anti-MAG neuropathy. Drugs including melphalan, thalidomide, lenalidomide, and bortezomib for POEMS syndrome and those including melphalan, thalidomide, lenalidomide, pomalidomide, bortezomib, ixazomib, and daratumumab for AL amyloidosis are considered. Since there will be more therapeutic options in the future, thereby enabling appropriate treatments for individual neuropathies, there is an increasing need for early diagnosis.

Skin and Nerve Neovascularization in POEMS Syndrome: Insights From a Small Cohort

Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS) syndrome is a rare systemic disorder linked to plasma cell dyscrasia and is related to elevation of vascular endothelial growth factor (VEGF). Diagnosis is still challenging and pathophysiology unclear. Because VEGF drives neovascularization, we investigated skin and nerve vascularization in 6 patients with POEMS syndrome compared with 5 control groups of polyneuropathies and healthy subjects (n = 104) from the University Hospital of Limoges between 2009 and 2018. We evaluated loss of small and large fibers in these patients. Skin and nerve vascularization were quantified manually on immunofluorescence using vessel staining (anti-α-SMA antibody). Dermal vascularization was significantly higher in POEMS syndrome than in other groups, but unrelated to loss of small fibers and VEGF. Perineurial vascularization was higher in POEMS syndrome than in healthy controls, and was related to loss of large fibers and VEGF level. Our study highlights the existence of neovascularization in skin of patients with this rare disorder. These data suggest that skin neovascularization could be an additional biomarker to help in the diagnosis and understanding of POEMS syndrome. Moreover, nerve neovascularization, driven by VEGF overexpression, may play a role in the pathophysiology of large fiber loss in this condition.

An Atypical Case of POEMS Syndrome Associated with Autonomic Dysfunction

A 52 year old patient showed, for two years, symptoms compatible with sensorimotor polyneuropathy preventing him from walking. An electroneuromyography found a demyelinating pattern suggesting Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). The patient did not respond to corticosteroid therapy and later suffered sexual Dysfunction, Swelling, Lymphadenopathy, Hypotension, astrointestinal dysmotility, urinary retention and neuropathic pain. Analysis of the Cerebrospinal Fluid (CSF) revealed elevated protein levels and Computed Tomography (CT) scan found sclerotic bone lesions. High Vascular Endothelial Growth Factor (VEGF) levels and the results of Lambda light-Chain monoclonal gammopathy in urine protein Electrophoresis Suggested a Diagnosis of POEMS syndrome. The most striking feature, in this case, was the patient’s heightened and atypical polyneuropathy without axonal injury even after an extended period of time, and significant and atypical dysautonomia.

Improvement of sexual function in POEMS syndrome after combination therapy of Lenalidomide and dexamethasone

BACKGROUND

POEMS syndrome is a rare paraneoplastic syndrome due to an underlying plasma cell neoplasm. Hypogonadism is the most common endocrine abnormality in POEMS syndrome. There is no data about improvement of hypogonadism and sexual dysfunction after appropriate treatment of POEMS syndrome so far. In this single-center prospective study, the efficacy of low-dose lenalidomide and dexamethasone combination therapy in the improvement of sexual and gonadal function in POEMS syndrome was evaluated.

RESULTS

Thirty-five patients with newly diagnosed POEMS syndrome were treated with Lenalidomide (10 mg daily for 21 days) and dexamethasone (40 mg once per week) for 12 cycles. The international index of erectile function (IIEF) in male patients, the female sexual function index (FSFI) in female patients, total testosterone, estradiol and vascular endothelial growth factor (VEGF) levels were reviewed. Sexual dysfunction was reported in 88.8 % (24/27)male and 90.9 % (10/11) female patients. 62.9 % (17/27) male and 25.0 % (3/12) female patients had hypogonadism. After 12-month treatment, the mean total FSFI score had increased from 17.1 ± 7.2 to 23.7 ± 7.2(p < 0.05). The arousal, orgasm and sex pain domains had been improved significantly. The mean IIEF scores had increased from 12.9 ± 13.0 to 20.5 ± 18.4 (p < 0.05). Erectile function, sexual desire and intercourse satisfaction had improved significantly at the end of treatment. No association between VEGF levels and sexual function improvement was found in both genders.

CONCLUSION

Combination therapy with low-dose lenalidomide plus dexamethasone is successful in improving sexual function in POEMS syndrome.

Prominent dysautonomia in a patient with POEMS syndrome

POEMS syndrome is a rare, multisystem disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and/or skin changes. Here we present an unusual case of a patient with POEMS syndrome who exhibited a prominent autonomic neuropathy.

Intraepidermal nerve fibre density in POEMS (Crow-Fukase) syndrome and the correlation with sural nerve pathology

OBJECTIVE

To examine intraepidermal nerve fibre densities (IENFDs) in patients with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin change (POEMS) syndrome.

METHODS

The IENFDs of 11 patients with POEMS syndrome were estimated. We determined whether IENFD was associated with patient clinical features or the estimated number of nerve fibres on complete cross-sections of biopsied sural nerves.

RESULTS

IENFD was significantly reduced (9.7±4.4fibres/mm) compared with normal controls (p<0.05), although the individual values varied from 1.4 to 14.4fibres/mm. The presence of glucose intolerance was significantly associated with a reduction of IENFD (p<0.05). The number of unmyelinated fibres was preserved at the sural nerve level and was not correlated with IENFD. In contrast, the number of myelinated fibres was correlated with IENFD (p<0.05).

CONCLUSIONS

Some of the patients presented with a severe IENFD reduction. Because the number of unmyelinated fibres was well preserved at the level of the sural nerve biopsy, this severe reduction may indicate involvement at the most distal nerve terminals of unmyelinated fibres. Although the reduction of IENFD becomes evident as polyneuropathy becomes severe, the effects of glucose intolerance should also be considered in patients with moderate to severe reductions.

Uncompacted Myelin Lamellae and Nodal Ion Channel Disruption in POEMS Syndrome

To elucidate the significance of uncompacted myelin lamellae (UML) and ion channel disruption at the nodes of Ranvier in the polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome, we evaluated sural nerve biopsy specimens from 33 patients with POEMS syndrome and from 7 control patients. Uncompacted myelin lamellae distribution was assessed by electron microscopy and immunofluorescence microscopy. In the POEMS patient biopsies, UML were seen more frequently in small versus large myelinated fibers. Paranodes and Schmidt-Lanterman incisures, where normal physiologic UM is located, were frequently associated with UM. Widening of the nodes of Ranvier (i.e. segmental demyelination) was not associated with UML. There was axonal hollowing with neurofilament condensation at Schmidt-Lanterman incisures with abnormal UML, suggesting axonal damage at those sites in the POEMS patient biopsies. Myelin sheath irregularity was conspicuous in large myelinated fibers and was associated with abnormally widened bizarrely shaped Schmidt-Lanterman incisures. Indirect immunofluorescent studies revealed abnormalities of sodium (pan sodium) and potassium (KCNQ2) channels, even at nonwidened nodes of Ranvier. Thus, UML was not apparently associated with segmental demyelination but seemed to be associated with axonal damage. These observations suggest that nodal ion channel disruption may be associated with functional deficits in POEMS syndrome patient nerves.

[Evaluation of sudomotor function]

From the aspect of physiological roles, sweating on the hairy skin is an important for thermoregulation of body, and that on glabrous skin (the palm or sole) works as an anti-skid material when gripping something or performing a delicate task using the fingertips (emotional sweating). Abnormal sweating, which can be global or localized, is classified into hyperhidrosis and hypohidrosis, and detection of abnormal sweating, such as Horner's syndrome and Harlequin syndrome, is clinically useful for regional diagnosis of neurological lesions. In addition, sudomotor function tests, where sweat secretion is induced by physiological or pharmacological stimuli, are useful for diagnosis of neurological disorders. In this manuscript, clinical evaluation of abnormal sweating from the aspect of neurological diagnosis is reviewed.