Peripheral Peripheral Neuropathy Neuropathy
Peripheral Peripheral NeuropathyNeuropathy
Peripheral NervePeripheral Nerve
MyelinMyelin : Current cannot flow: Current cannot flow AxonAxon : Not nerves left: Not nerves left
Types of nerve fibersTypes of nerve fibers DiameterDiameter ConductionConduction Function Function
micronsmicrons Velocity m/sVelocity m/s
AA alpha 1-20alpha 1-20 70-11070-110 Motor, ProprioceptionMotor, Proprioception
beta 5-10beta 5-10 30-6030-60 TouchTouch
gama 3-6gama 3-6 20-3020-30 Fusimotor, spindlesFusimotor, spindles
delta 2-5delta 2-5 20-30 20-30 Sharp painSharp pain
BB <3 <3 5-155-15 Autonomic, pregangl.Autonomic, pregangl.
CC <1.3 <1.30.5-20.5-2 Slow painSlow painNon myelinatedNon myelinated
The Peripheral Nervous SystemThe Peripheral Nervous System MotorMotor: weakness, : weakness,
atrophyatrophy Sensory lossSensory loss
Large Fibers (position)Large Fibers (position) Small fiber (pain)Small fiber (pain)
Reflex lossReflex loss Autonomic symptomsAutonomic symptoms
(redness, dizziness, ED)(redness, dizziness, ED)
DefinitionsDefinitions NeuropathyNeuropathyPathological process affecting a Pathological process affecting a peripheral nerve/speripheral nerve/s
MononeuropathyMononeuropathyA single nerve affectedA single nerve affected
Mononeuritis multiplexMononeuritis multiplex Multiple mononeuropathy or Multifocal neuropathyMultiple mononeuropathy or Multifocal neuropathy
Polyneuropathy Diffuse symmetrical disease usually beginning peripherally Acute/Chronic Static/Prog Relapsing/Recovering Motor Sensory
Sensrimotor(Mixed) AutonomicDemyelinating Axonal
Radiculopathy Nerve root disease
Mechanisms of damageMechanisms of damage Demyelination Demyelination Myelin sheath disrupted
GBS Post Diphtheric HSMN
Axonal degeneration Axonal degeneration Axon damage
Toxic neuropathies
Wallerian degenerationWallerian degeneration Nerve section CompressionCompression Focal demyelination
Entrapment-Carpel tunnel syndrome
InfarctionInfarction Arteritis
Polyarteritis nodosa Churg-Strauss synd. DM
InfiltrationInfiltration Infiltration
Leprosy Sarcoidosis
ClassificationClassificationEXAMINATION FINDINGSEXAMINATION FINDINGS
Purely Motor or Sensory or Purely Motor or Sensory or Sensorimotor?Sensorimotor?
Proximal or distal? Symmetric or Proximal or distal? Symmetric or asymmetric?asymmetric?
Multifocal, generalized, regional?Multifocal, generalized, regional? Upper limbs, lower limbs, neck, trunk?Upper limbs, lower limbs, neck, trunk?
TIMINGTIMING Acute or chronic?Acute or chronic?
ASSOCIATED FINDINGSPainful or painless?
Hereditary or sporadic?
ELECTRODIAGNOSISAxonal or demyelinating?
LABORATORYParaprotein present? Type?
Antibody against nerve?CSF protein level?
HISTOLOGYInflammatory Cells
EpidemiologyEpidemiology
Prevalence Prevalence ~ 2.4%~ 2.4% ~ 8% in people older than 55 years~ 8% in people older than 55 years
DM is most common causeDM is most common cause
EpidemiologyEpidemiology
Other common systemic causesOther common systemic causes Metabolic disordersMetabolic disorders Infectious agentsInfectious agents VasculitisVasculitis ToxinsToxins DrugsDrugs AutoimmunityAutoimmunity InheritedInherited
DiagnosisDiagnosis
Most important details to determineMost important details to determine DistributionDistribution DurationDuration Course Course
DiagnosisDiagnosis
Clinical manifestations vary widelyClinical manifestations vary widely Altered sensationAltered sensation PainPain Muscle weakness or atrophyMuscle weakness or atrophy Autonomic symptomsAutonomic symptoms
Laboratory Screening for Laboratory Screening for “Treatable” Neuropathy?“Treatable” Neuropathy?
B12B12 Not truly length-dependentNot truly length-dependent
DiabetesDiabetes This type of neuropathy This type of neuropathy generally a late findinggenerally a late finding
ANA, chronic disease ANA, chronic disease screenscreen
Screen for connective tissue Screen for connective tissue diseases (late finding)diseases (late finding)
TSHTSH If positive, have you proven If positive, have you proven anything?anything?
ESRESR If onset is recentIf onset is recent
HIVHIV Risk FactorsRisk Factors
Review medicationsReview medications Big questionBig question
DiagnosisDiagnosis
Electro diagnostic studiesElectro diagnostic studies Sensitive, specific, validatedSensitive, specific, validated Extension of neurologic examExtension of neurologic exam
Nerve conduction studies (NCS)Nerve conduction studies (NCS) Needle electromyography (EMG)Needle electromyography (EMG)
DiagnosisDiagnosis
Establish distributionEstablish distribution MononeuropathyMononeuropathy Mononeuropathy multiplexMononeuropathy multiplex PolyneuropathyPolyneuropathy
Determine primary pathologyDetermine primary pathology Demyelinating Demyelinating AxonalAxonal
MononeuropathyMononeuropathy
Focal lesion involving a single nerveFocal lesion involving a single nerve Electro diagnostic studies indispensibleElectro diagnostic studies indispensible
Localize site of injuryLocalize site of injury Determine severity of lesionDetermine severity of lesion
MononeuropathyMononeuropathy
CausesCauses EntrapmentEntrapment
Carpal tunnel syndrome is most commonCarpal tunnel syndrome is most common Foot dropFoot drop
Focal compressionFocal compression TraumaTrauma
Mononeuropathy Mononeuropathy MultiplexMultiplex
Separate/noncontiguous involvementSeparate/noncontiguous involvement SimultaneouslySimultaneously SeriallySerially
PatternPattern RandomRandom MultifocalMultifocal
Frequently evolves quicklyFrequently evolves quickly
Mononeuropathy Mononeuropathy MultiplexMultiplex
Urgent assessment for vasculitisUrgent assessment for vasculitis Polyarteritis nodosaPolyarteritis nodosa Churg-Strauss diseaseChurg-Strauss disease Connective tissue diseasesConnective tissue diseases
Rheumatoid arthritisRheumatoid arthritis Sjogren’s syndromeSjogren’s syndrome
PolyneuropathyPolyneuropathy
Most commonly distal symmetricalMost commonly distal symmetrical Fiber effect is length-dependentFiber effect is length-dependent Toes and soles affected firstToes and soles affected first AssociationsAssociations
Systemic diseasesSystemic diseases Metabolic disordersMetabolic disorders Exogenous toxinsExogenous toxins
PolyneuropathyPolyneuropathy
Diabetes is prototypeDiabetes is prototype Chronic, sensory and motorChronic, sensory and motor Commonest in developed worldCommonest in developed world Alcoholism is the second most commonAlcoholism is the second most common
PolyneuropathyPolyneuropathy
Early symptoms Early symptoms Sensory abnormalitiesSensory abnormalities
NumbnessNumbness BurningBurning ParesthesiasParesthesias Dysesthesias Dysesthesias
Distally predominantDistally predominant SymmetricalSymmetrical
PolyneuropathyPolyneuropathy
Evolution is centripetalEvolution is centripetal Symptoms spread up legsSymptoms spread up legs
Sensory lossSensory loss DysesthesiasDysesthesias
Ankles jerks are depressedAnkles jerks are depressed Patients have trouble walking on their heelsPatients have trouble walking on their heels Foot plantar flexion remains strongFoot plantar flexion remains strong
PolyneuropathyPolyneuropathy
Symptoms noticed in fingertipsSymptoms noticed in fingertips NumbnessNumbness Dysesthesias Dysesthesias
Advanced picture is easily recognizableAdvanced picture is easily recognizable Stocking-glove sensory lossStocking-glove sensory loss Distal muscle wasting and weaknessDistal muscle wasting and weakness Absent tendon reflexesAbsent tendon reflexes
PolyneuropathyPolyneuropathy
Sub classificationSub classification Historical features are indispensible Historical features are indispensible
Other medical conditionsOther medical conditions Symptoms of systemic diseaseSymptoms of systemic disease Recent viral or other infectious diseasesRecent viral or other infectious diseases Recent vaccinationsRecent vaccinations Institution of new medicationsInstitution of new medications
PolyneuropathyPolyneuropathy
Exposure to toxinsExposure to toxins AlcoholAlcohol Heavy metalsHeavy metals Organic solventsOrganic solvents
Family historyFamily historyDuration and clinical course are helpfulDuration and clinical course are helpful
Acute = days to weeksAcute = days to weeks Chronic = months to yearsChronic = months to years
Laboratory InvestigationsLaboratory Investigations
CBCCBC SUGARSUGAR TFTsTFTs
ESRESR CRPCRP
UREAUREA
B12B12 Methylmalonic acidMethylmalonic acid HomocysteineHomocysteine
FolateFolate
TreatmentTreatment
GeneralGeneral Subtype specificSubtype specific
Diabetes mellitusDiabetes mellitus Renal insufficiencyRenal insufficiency HypothyroidismHypothyroidism Vitamin B12 deficiencyVitamin B12 deficiency Systemic vasculitisSystemic vasculitis
TreatmentTreatment
GeneralGeneral PainPain
Antiepileptic drugsAntiepileptic drugs AntidepressantsAntidepressants Tramadol Tramadol
TreatmentTreatment
Preventative and palliativePreventative and palliative Weight reductionWeight reduction Assiduous foot careAssiduous foot care Good shoesGood shoes Ankle-foot orthoses as neededAnkle-foot orthoses as needed
Several organizations provide Several organizations provide supportsupport
Chronic Length Dependent Chronic Length Dependent NeuropathyNeuropathy
Begins in toes or feetBegins in toes or feet Stocking distributionStocking distribution
Progresses rostrallyProgresses rostrally Tops and bottoms of Tops and bottoms of
feetfeet
Weakness begins in Weakness begins in ankles when ankles when sensation reaches sensation reaches calvescalves
Sometimes diagnosable, Never treatable?Sometimes diagnosable, Never treatable?
Phenotype CIDPPhenotype CIDP
Small DifferentialSmall Differential
Phenotype-MADSAM Phenotype-MADSAM NeuropathyNeuropathy Key DDx: Key DDx:
Brachial plexopathiesBrachial plexopathies Vasculitis Vasculitis
mononeuropathy mononeuropathy multiplexmultiplex
Compression Compression neuropathiesneuropathies
HNPP (genetic testing)HNPP (genetic testing)
Multifocal Motor Multifocal Motor Neuropathy (MMN)Neuropathy (MMN) Almost always in Almost always in
hands and wrists hands and wrists Pattern of weakness is Pattern of weakness is
in the distribution of in the distribution of individual peripheral individual peripheral nervesnerves i.e. severe involvement in i.e. severe involvement in
ulnar distribution sparing ulnar distribution sparing medianmedian
Lack of atrophy in Lack of atrophy in weak musclesweak muscles
No pathological No pathological reflexesreflexes
UncertaintyUncertainty
Many cases are not easily definable Many cases are not easily definable because of multiplicity of patternsbecause of multiplicity of patterns
Cases that are not clearly untreatable are Cases that are not clearly untreatable are possibly treatablepossibly treatable