Retrospective Analysis Of Clinical And Electrophysiological Features Of The Patients With POEMS Syndrome

BackroundPOEMS syndrome is a paraneoplastic disorder with a demyelinating and axonal loss peripheral neuropathy,the acronym reflects the common features:Polyneuropathy,Organomegaly,Endocrinopathy,Monoclonal protein and Skin changes.Peripheral neuropathy is usually the dominant feature of POEMS syndrome,it is often mistaken for chronic inflammatory demyelinating polyradiculoneuropathy(CIDP)as both present as subacute motor predominant polyradiculoneuropathies,both share other features,such as albuminocytologial dissociation and demyelinating features on electrophysiology.Differentiation of POEMS syndrome from CIDP is important as they require different therapies and share different prognosis.ObjectiveThrough a retrospective analysis of 24 cases of POEMS syndrome patients and 48 cases of CIDP patients with clinical data and electrophysiological parameters from Qilu hospital,we compare and explore the NCS/EMG characteristics that might differentiate POEMS from CIDP and reduce missed diagnosis and misdiagnosis.Methods24 patients who met the Dispenzieri 2003 criteria for POEMS syndrome and 48 patients who met the America clinical criteria for CIDP were entered into this study,all the patients were hospitalized in Qilu hospital of Shandong university from January 2005 to May 2016.We analyze their sex,age,course of disease,clinical symptoms and signs,characteristics of CSF,blood,imaging studies,NCS/EMG,etc.The obtained data was statistically analyzed with SPSS 19.0.Results1.Clinical featuresOf the 24 POEMS syndrome patients,10 were females and 14 were males.Patients ranged 30-71 years old,the average age is 50.58 years old.The average time interval between onset to diagnosis is 26.08 months,the longest even 10 years.The initial symptom of 21 cases(87.5%)were polyneuropathy,3 cases(12.5%)were extravascular volume overload,include 1 case was peripheral edema,1 case was ascites,1 case was pleural effusions.Whereas,the incidence ratio of men and women was 29:19 in 48 CIDP patients.And the average age of CIDP patients is 50.27 years old,there was no difference in age(p=0.93)between the groups,but the average time interval between onset to diagnosis is different between the groups,as what is 5.58 months for CIDP patient(p=0.002).Both POEMS syndrome patients and CIDP patients showed subacute or chronic sensorimotor polyneuropathy.The onset of both diseases are symmetrically(p=0.546),but POEMS syndrome patients usually emerge sensory symptoms,then appear motor symptoms,whereas CIDP patients is different(p=0.024),they appear equal motor,sensory,or sensorimotor symptoms.POEMS patients showed distal dominant muscle weakness with amyotrophy,which was mainly seen in the lower extremities(p=0.024),whereas in CIDP patients proximal as well as distal muscles were involved and both upper and lower extremities were almost equally involved(p=0.308).Positive sensory symptoms were significantly different,POEMS patients had neuropathic pain much more frequently than CIDP patients(p=0.027),but there was no difference in hypesthesia of distal limbs(p=0.316)and vibratory sensory loss(p=0.052)between the groups.Cranial nerves never involved in POEMS patients whereas CIDP patients could have cranial nerve palsy(p=0.034).Moreover,there was no difference in areflexia(p=0.333)and CSF protein(p=0.483)between the groups.POEMS patients showed monoclonal plasma cell disorder,organomegaly,endocrimopathy,shin changes,extravascular volume overload,thrombocytosis,pulmonary hypertension,renal dysfunction,etc,apart from polyneuropathy.But CIDP patients have not the multisystem symptoms at the same time.2.Electrophysiological FeaturesPOEMS patients demonstrated reduction in CMAPs/SNAPs amplitudes(especially in the lower limbs),low conduction velocities,prolonged distal latencies and prolonged F wave/H reflex latencies,EMG demonstrated neurogenic abnormalities.Compared with CIDP controls,POEMS patients demonstrated:(1)greater reduction of motor and sensory amplitudes,(2)greater slowing of motor and sensory conduction velocities,(3)greater prolonged motor and sensory distal latencies,(4)greater prolonged F wave and H reflex latencies,and greater number of absent responses,(5)less frequent conduction block,(6)greater number of fibrillation potentials,(7)higher terminal latency indices.ConclusionsPOEMS syndrome occurs in middle-aged and old male patients mostly.Symptoms of peripheral neuropathy usually dominate the clinical picture,and multiorgan involved in the disease development.Protein electrophoresis and immunofixation was informative in diagnosing POEMS syndrome.NCS/EMG of POEMS syndrome suggests both axonal loss and demyelination,usually the lower limbs are more severe than the upper limbs.Compared with CIDP,there is greater axonal loss(reduction of motor amplitudes and increased fibrillation potentials),greater slowing of the intermediate nerve segments,less common conduction block.These findings imply that the pathology of POEMS syndrome is diffusely distributed(uniform demyelination)along the nerve where the pathology of CIDP is probably predominantly proximal and distal,and are important to differentiate of POEMS syndrome from CIDP.