Small Fiber Poluneuropathy: An · PDF fileFibromyalgia ... diseases affecting the...
Transcript of Small Fiber Poluneuropathy: An · PDF fileFibromyalgia ... diseases affecting the...
10/10/17
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Small Fiber Poluneuropathy: An Update
Charles E. Argoff, M.D.
Professor of Neurology
Albany Medical College
Director, Comprehensive Pain Center
Albany Medical Center
Disclosures
• Receive consulting fees from Pfizer, Nektar, Depomed, Salix, Daiichi Sankyo, Grunenthal, and Quest.
• Receive honoraria from Allergan, Depomed, AstraZeneca, Daiichi Sankyo, BDSI, Collegium, and Avanir.
• Stockholder of Pfizer and Depomed. • Receives royalties from Elsevier.
PresentationObjectives
§ Todescribethedefinitionofsmallfiberpolyneuropathy
§ Todescribeapproachestomakingthediagnosisofsmallfiberpolyneuropathy
§ Todescribetherangeofmedicalconditionsassociatedwithsmallfiberpolyneuropathy
§ Todescribecurrentandemergingtreatmentsofsmallfiberpolyneuropathy
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“Discouraging Data on the Antidepressant (AS WELL AS MANY OTHER TREATMENTS)”
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Gabapentininthetreatmentofpainfuldiabeticneuropathy* Placebo
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Example:Mechanistic Characterization of Pain Any combination may be present
in a given individual Peripheral
(nociceptive)
■ Inflammation or mechanical damage in tissues
■ NSAID, opioid responsive
■ Responds to procedures
■ Classic examples ■ Acute pain due to
injury ■ Osteoarthritis ■ Rheumatoid arthritis ■ Cancer pain
Peripheral Neuropathic
■ Damage or dysfunction of peripheral nerves
■ Responds to both peripheral (NSAIDs, opioids, Na channel blockers) and central (TCA’s, neuroactive compounds) pharmacological therapy
■ Classic examples ■ Diabetic neuropathic
pain ■ Post-herpetic
neuralgia
Central Neuropathic or Centralized Pain
■ Characterized by central disturbance in pain processing (diffuse hyperalgesia/allodynia)
■ Responsive to neuroactive compounds altering levels of neurotransmitters involved in pain transmission
■ Classic examples ■ Fibromyalgia ■ Irritable bowel
syndrome ■ TMJD ■ Tension headache
Mixed Pain States
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Which person has pain?
Differential diagnosis- Widespread Pain
■ Rheumatic ■ Arthritis (OA, RA) ■ Polymyalgia Rheumatica ■ Osteomalacia ■ Myopathy ■ Spondyloarthropathies ■ Systemic Lupus
Erythematosus
■ Neurologic ■ Multiple sclerosis ■ Chiari malformation ■ Spinal stenosis ■ Radiculopathy ■ Polyeuropathy ■ Fibromyalgia
■ Endocrine ■ Hypothyroidism ■ Diabetes ■ IS SMALL FIBER
POLYNEUROPATHY OVERLOOKED?
Background
§ Peripheralneuropathyisexperiencedbyapproximately40millionpeopleintheUS
§ Manyperipheralneuropathiesaremixedneuropathieswithbothlargefiberandsmallfiberinvolvement
§ Increasinglyrecognizedisthedemonstrationofspecificinvolvementofsmallmyelinatedorunmyelinatedfibers,e.g.smallfiberneuropathies
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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WhatisNeuropathicPain?
§ Painarisingasadirectconsequenceofdiseasesaffectingthesomatosensorysystem.Gradingsystem:definite,probable,possibleR-DTreedeetal.Neurology2008,ProposedbyIASPNeuropathicPainSpecialInterestGroup.
§ InPlainEnglish:Painfromthenerves,spinalcord,orbrain.Notoriginatinginthebones,muscles,organs.
CommonNeuropathicPainDiagnoses § DiabeticPeripheralNeuropathy*
§ PostHerpeticNeuralgia*§ RadicularPain§ TraumaticPeripheralNerveInjury§ ComplexRegionalPainSyndrome§ ChronicPostopPain§ PhantomLimbPain§ HIVrelatedneuropathy§ SpinalCordInjury*§ Post-strokepain§ TrigeminalNeuralgia*§ SmallFiberPolyneuropathies
* FDA approved medications available
SmallFiberPolyneuropathyDefinition
§ Smallfiberneuropathies(SFN)resultfromdamagetotheperipheralnervesaffectingsmallmyelinatedA-DeltaandunmyelinatedCfibers.
§ Thefibersaffectedincludebothsmallsomaticaswellasautonomicfibers
§ Thermalperceptionandnociceptionaresubservedbysmallfibers
§ Entericfunctionisalsosubservedbysmallfibers
§ LARGEfibersareheavilymyelinatedandinvolvedinmusclecontrol,aswellastouch,vibrationadnpositionsense
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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SmallFiberPolyneuropathyDefintion-2
§ MostSFNsoccurinalength-dependentfashion–firststockingdistributionchangesandthenlaterglovedistribution
§ Rarely,non-lengthdependentSFNcanresultsinsymptomsinvolvingtheface,trunk,proximallimbs,orothermorelocalizedareas
§ Thepathogenesisofinjurytosmallfibersisnotwellunderstood
§ SFNcanprogresstoinvolvelargefibersaswell
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
SmallFiberPolyneuropathy:BIGimpactonqualityoflife
§ OnlyonestudyasmeasuredtheimpactspecificallyonSFPNonqualityoflife
§ 265patientsenrolled§ SFN-SIQ,VAS,36itemshortformhealthsurveyevaluated
§ SFPNpatientsdemonstratedamarkedoverallreductioninqualityoflife
§ PhysicalandmentalmeasuresweredecreasedChan AC, Wilder-Smith EP. Small fiber neuropathy: getting bigger! Muscle Nerve
53:671-682, 2016
DisordersAssociatedwithSFN
§ Diabetes§ ImpairedGlucose
Tolerance
§ MetabolicSyndrome
§ Sarcoidosis§ ThyroidDysfunction§ HIV§ VitaminB12Deficiency
§ VitaminB1Deficiency
§ Chemotherapydrugs§ AntiviralAgents§ CeliacDisease§ Sjogren’sSyndrome
§ ParaneoplasticSyndromes
§ Paraprotenemia§ RheumatoidArthritis
§ Idiopathic(upto50%!)
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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DisordersAssociatedwithSFN-2
§ Guillain-BarreSyndrome
§ ChronicInflammatoryDemyelinatingPolyneuropathy(CIDP)
§ RestlessLegSyndrome§ HepatitisC§ SystemicLupus
Erythematosus
§ Amylodosis§ Fabry’sDisease§ EhlersDanlos
Syndrome§ HereditarySensory
Neuropathies§ HereditaryAutonomic
Neuropathies§ ?Centralpoststroke
pain(moretofollow)Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber
Neuropathy Curr Pain Headache Rep (2011) 15:193-200
DisordersassociatedwithSFN-3
§ Alcoholuse§ Rabies,varicellaor
Lymevaccine§ Anti-TNFinhibitors§ Metonidazole§ Linezolid§ Statins§ Sodium
channelopathies
§ Parkinsondisease§ Pompedisease§ Wilsondisease§ ALS§ FragileX§ Xlinked
adrenoleukodystrophy§ Chronicrenaldisease
Chan AC, Wilder-Smith EP. Small fiber neuropathy: getting bigger! Muscle Nerve 53:671-682, 2016
SFNPathophsyiology-PossibleroleofSodiumChannelmutations
§ Geneticvariantsinthestructure/functionofsodiumchannelsmayleadtoeitherlossofpainsensitivityorenhancedpain
§ InactivatingmutationsinSCN9A,whichencodesNav1.7isassociatedwithcongenitalinsensitivitytopain
§ GainoffunctionmutationsinSCN9AmayresultinSFN§ VariousmutationsinTRPA1orNAv1.8(SCN10A)andNav
1.9(SCN11A)alsomayleadtoSFN
§ Mightthisinformationleadtonewtreatments?
Bennett DL, Woods CG. Painful and painless channelopathies. Lancet Neurol 2014 Jun;13(6):587-99.
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Polyneuropathyiesmayinvolvesmallandlargenervefibers
Large-fiber neuropathy
Small-fiber neuropathy
Symptoms Numbness, pins and needles, tingling, poor balance
Pain: burning, electric shocks, stabbing pain, numbness
Exam Findings
Reflexes, proprioception Vibration, +/- motor
Thermal, pin-prick sensation, allodynia
Functional changes
Pressure, balance, fall risk Nociception; protective sensation
Diagnostic test
EMG/NCV, sural nerve biopsy
QST, nerve biopsy, Intraepidermal nerve fiber density (skin biopsy)
SFNSymptoms
§ Symptomsvarywidelyinseverity§ Oftenaffectedindividualsdescribeagradualonsetofvaguedistalsensorydisturbances
§ Examplesincludefeelinglikethereissandintheperson’sshoe,asockfeelingasifithaspebblesinit,pinsandneedlesensations,coldpainfulsensationsortingling.
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
SFNSymptoms-2
§ Burningpainintheextremities,sometimessevere
§ Allodyniaandhyperesthesia§ Socksorbedsheetsmaybepainful§ Symptomsareoftenworseatnight
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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SFNSymptoms-3
§ Autonomicandentericdysfunctionincluding:dryeyes,drymouth,lightheadednesswithchangesinposture,syncope,abnormalitiesofsweating,erectiledysfunction,GIsymptomssuchasnauseaandemesis,constipation,diarrhea,changesinurinaryfrequencyincludingnocturia.
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
SFN-Diagnosis
§ Normalorpracticallynormalbasicphysicalandneurologicalexamination!!!
§ However,possiblefindingsincludedecreasedpinprick,diminishedthermalsensation,hyperalgesia,dryskin
§ Adetailedhistoryisvitaltomakingthediagnosis
§ Ancillarytestingmaybehelpfulaswell
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
SFN-Diagnosis-2
§ VariouswrittentoolssuchastheNeuropathicPainSymptomInventorymaybehelpful
§ QuantitativeSensoryTesting-thiscandetectthresholdsofthermalpain,thermalsensationandvibrationforexample.ContactHeatEvokedPotentialsattemptstolinkperipheralactivationtocentral.
§ QuantitativeSudomotorAxonReflextesting(QSART)
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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DiagnosticStudiesandLimitationsStudies§ Bloodstudies§ X-ray,CT,MRI§ Electromyography
(EMG)§ Nerveconduction
velocity(NCV)§ Quantitativesensory
testing(QST)§ Skinbiopsy
LimitationsofEMG/NCV§ Insensitiveinacuteinjury§ Normalresultdoesnotrule
outneuropathicpain§ Cannotassessfunctionof
small-fibernervesinvolvedinmostneuropathicpain
Galer BS, Dworkin RH. A Clinical Guide to Neuropathic Pain. McGraw-Hill Companies; 2000.
SFN-Diagnosis-3§ SkinBiopsy-thishasbecomewidelyacceptedasa
techniquetoevaluatethestructureofsmallnervefibers.
§ Thestandardisa3-mmskinpunchbiopsythatcanbetakenfromanywhereoverthebody.
§ Duetotheneedtocomparetonormalvaluesthelowerextremityismostcommonlyassessed(alsolengthdependentSFNmorecommonthannon-lengthdependent)
§ Theresultsareexpressedasthenumberofintraepidermalfiberspermm
§ Thesensitivity(78-92%)andspecificity(65-90%)isfairlyhighforthistechnique
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
LossofskinnervefibersinPHN
The density of epidermal nerve endings in previously shingles-affected skin
0
1000
2000
3000
4000
Neurite densities from individual subjects in descending order (n = 38)
Neu
rite
s/m
m2 s
kin
surf
ace
area
Subjects without PHN
Subjects with PHN
Oaklander AL, Pain, 2001
Oaklander AL, et al Ann Neurol 1998; Oaklander AL, et al Pain 2001
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Smallfiberpolyneuropathy-blood/othertests
§ Metabolic:thyroidfunctions,HbA1C,FBS§ Nutritional:CBC,HepaticProfile,VitaminB1andB12
§ Infectious:CRP,HIV,Lyme,HBV,HCV§ Autoimmune:ESR,ANA,Anti-ENA,ANCA,anti-gliadin,RF,serumACE,?CXR
§ Paraneoplastic:Tumormarkers,LDH,Myelomascreen,SPE,anti-Huandanti-CV2/CRMP-5abChan AC, Wilder-Smith EP. Small fiber neuropathy: getting bigger! Muscle Nerve
53:671-682, 2016
Smallfiberpolyneuropathy-blood/othertests(continued)
§ Neurotoxins:urineandbloodtoxicology,reviewdrughistory
§ Herditary:alpha-galactosidaseA,globotriaosylceramidelevels,renalpanel,urineprotein,genetictestingforSCN9AorSCN10A
§ Lumbarpuncture:ifyoususpectinflammatory,auto-immuneorparaneoplasticetiologiesChan AC, Wilder-Smith EP. Small fiber neuropathy: getting bigger! Muscle Nerve
53:671-682, 2016
SFN-Treatment
§ Treatthetreatable!IfanunderlyingcauseofSFNcanbedetermined,optimaltreatmentofthecausativeconditionmaylessenthesymptomsofSFN
§ FewstudiesandnoguidelineshaveexaminedthepharmacologictreatmentofthepainassociatedwithSFN
§ Inonesuchstudy,bothgabapentinandtramadolwerefoundtobeeffectiveforSFN
Hovaguimian A, Gibbons CH. Diagnosis and Treatment of Pain in Small-fiber Neuropathy Curr Pain Headache Rep (2011) 15:193-200
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EFNS,EuropeanFederationofNeurologicalSocieties;IASP,InternationalAssociationfortheStudyofPain;NeuPSIG,NeuropathicPainSpecialInterestGroup
Neuropathicpainrecommendationsofvarioussocieties
OpioidTramadol
FirstlineSecondlineThirdline
TCAGBP/PGB
Lidocaine5%plaster
SNRI
(Opioid)
OpioidLamotrigineCapsaicin
CanadianPainSociety
TCAGBP/PGB
SNRILidocaine5%
Opioid
(exceptmethadone)
TCA,SNRIGBP/PGB
Lidocaine5%Opioid
(specificcircumstances)
EFNS,EuropeNeurology
IASPNeuPSIG
ParoxetineBupropionNMDA
antagonistFourthline Methadone
AttalN,etal.EurJNeurol.2006;13(11):1153-1169.DworkinRH,etal.Pain.2007;132(3):237-251.MoulinDE,etal.PainResManag.2007;12(1):13-21.
SFN-IsIVIG(intravenousimmunoglobulin)anEmergingTreatment?
§ Arecentreportdescribed3patientswithsarcoidosisandSFNwhowereexperiencingseverepainaswellasdysautonomia
§ EachpatienthadbiopsyprovenSFN
§ Eachpatienthadfailedtoresponseto“conventional”analgesic/symptomaticapproaches
§ EachpatientreceivedaninitialdoseofIVIG2g/kgfollowedby1g/kgdosesatregularintervals-eachwithdramaticresolutionofpainandautonomicsymptoms
§ Furtherlargerstudiesarewarranted
Parambi JG, Tavee JD, Zhou L, et al. Efficacy of intravenous immunoglobulin for small-fiber neuropathy associated with sarcoidosis. Resp Med 2011 Jan;105(1):101-5.
SFN-IsIVIG(intravenousimmunoglobulin)anEmergingTreatment?-2
§ LimiteddataforSjogren’ssyndrome-IVIG2g/kg§ Juvenileonsetunexplainedwidespreadpaintreatedwith
IVIGin15patientsbyOaklanderetal-treatedat2g/kg/monthatleast3times-62%demonstratedsignificantimprovement
§ Inanotherstudy,46patientswithSFPNassociatedwithdysautonomiaweretreatedwithoneormoreIVIGtreatment-forpatientswithpainintensitylevels≥3orwithsignificantdysautonomia,thetreatmentwashelpful
Oaklander A, Immunotherapy Prospects for Painful Small-fiber Sensory Neuroapthies and Ganglionopathies. Neurotherapeutics 2015
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SFPNandFibromyalgia
§ Approximately50%ofpatientswhohavebeendiagnosedwithFibromyalgiainseveralpublishedstudieshavedemonstratedfindingsconsistentwithSFPNondiagnosticbiopsies-studiestobereviewedonsubsequentslides
§ Whatdoesthatmean?§ WhatdoesthatmeanaboutinterpretingFMstudiesthathavealreadybeenpublished?
CWP,SFPNandFibromyalgiaI
§ 27patientswithfibromyalgiawhosatisfiedthe2010ACRcriteriawerecomparedto30matchedcontrols
§ 41%ofskinbiopsiesfromfibromyalgiasubjectscomparedto3%fromcontrolswerediagnosticforSFPN
§ TheMichiganNeuropathyScreeningInstrumentandUtahEarlyNeuropathyScalescoreswerehigherinfibromyalgiapatients
Oaklander AL, et al. Objective evidence that small-fiber polyneuropathy underlies some illnesses currently labeled as fibromyalgia Pain 2013 Nov;154(11):2310-6.
CWP,SFPNandFibromyalgiaII§ 25patientswithfibromyalgiawerecomparedto10depressedpatientsandcontrols
§ SmallfiberevaluationincludedQST,pain-relatedevokedpotentialsandquantifiedintraepidermalnervefiberdensityandregeneratingIENFofthelowerlegandupperthigh
§ ComparedwithcontrolsubjectsfibromyalgiapatientsBUTnotdepressedpatientshadimpairedsmallfiberfunction
Uceyler N, et al. Small fibre pathology in patients with fibromyalgia syndrome. Brain 2013 Jun;136(Pt6):1865-67.
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CWP,SFPNandFibromyalgiaII(continued)§ Skinbiopsyfindingsdemonstratedthattotaland
regeneratingIENFsatthelowerlegandupperthighwerereducedinpatientswithfibromyalgiacomparedwithcontrols
§ Areductioninunmyelinatednervefiberbundleswasseeninpatientswithfibromyalgiacomparedwithdepressedandcontrolsubjects
§ Theauthorsconcludedthattheresultspointtowardsaneuropathicnatureoffibromyalgia.
Uceyler N, et al. Small fibre pathology in patients with fibromyalgia syndrome. Brain 2013 Jun;136(Pt6):1865-67.
Summary
§ MultiplemedicalconditionsareassociatedwithSFN
§ Themechanism(s)ofSFNarenotcompletelyunderstoodandmayvarydependingontheindividual/specificassociateddisorder
§ RecognizingSFNanditsexistenceinperhapsmoreconditionsthanpreviouslyrecognizedmayleadtoimprovedtreatmentapproaches