evaluating the patient with suspected radiculopathy · pll; predisposes to posterolateral hnp cauda...

EVALUATING THE PATIENT WITH EVALUATING THE PATIENT WITH SUSPECTED RADICULOPATHYSUSPECTED RADICULOPATHY

Timothy R. Dillingham, M.D., M.S Timothy R. Dillingham, M.D., M.S Professor and Chair,Professor and Chair,

Department of Physical Medicine and Department of Physical Medicine and RehabilitationRehabilitation

The Medical College of Wisconsin.The Medical College of Wisconsin.

RadiculopathiesRadiculopathies

PathophysiologicalPathophysiological processes affecting the processes affecting the nerve rootsnerve rootsVery common reason for EDX referralVery common reason for EDX referral

CAUSES OF CAUSES OF RADICULOPATHYRADICULOPATHY

HNPHNPRadiculiitisRadiculiitisSpinal StenosisSpinal StenosisSpondylolisthesisSpondylolisthesisInfectionInfectionTumorTumorFacet Facet SynovialSynovial CystCystDiseases: Diabetes, AIDPDiseases: Diabetes, AIDP

MUSCULOSKELETAL MUSCULOSKELETAL DISORDERS : UPPER LIMB DISORDERS : UPPER LIMB Shoulder BursitisShoulder BursitisLateral Lateral EpicondylitisEpicondylitisDequervainsDequervainsTrigger fingerTrigger fingerFibrositisFibrositisFibromyalgiaFibromyalgia / regional pain syndrome/ regional pain syndrome

NEUROLOGICAL NEUROLOGICAL CONDITIONS MIMICKING CONDITIONS MIMICKING

CERVICAL CERVICAL RADICULOPATHYRADICULOPATHY

Entrapment/Compression neuropathiesEntrapment/Compression neuropathies–– Median, Radial, and UlnarMedian, Radial, and UlnarBrachial NeuritisBrachial NeuritisMultifocalMultifocal Motor NeuropathyMotor NeuropathyNeed Extensive EDX study to R/O other Need Extensive EDX study to R/O other conditionsconditions

MUSCULOSKELETAL MUSCULOSKELETAL DISORDERS : LOWER LIMBDISORDERS : LOWER LIMBHip arthritisHip arthritisTrochanteric BursitisTrochanteric BursitisIlliotibialIlliotibial Band SyndromeBand SyndromePatellofemoralPatellofemoral PainPainPesPes AnserinusAnserinus BursitisBursitisBakers CystBakers CystPlantar Plantar FasciitisFasciitisMortonsMortons NeuromaNeuroma

NEUROLOGICAL NEUROLOGICAL CONDITIONS MIMICKING LSRCONDITIONS MIMICKING LSR

Diabetic Diabetic AmyotrophyAmyotrophyMononeuropathiesMononeuropathies–– FemoralFemoral–– TibialTibial–– Common PeronealCommon PeronealNeed Extensive EDX studyNeed Extensive EDX study

AnatomyAnatomy

ANATOMY AND IMPLICATIONSANATOMY AND IMPLICATIONS

Sensory (DRG) in the Sensory (DRG) in the intervertebralintervertebralforamen, spared with radiculopathiesforamen, spared with radiculopathiesPLL; predisposes to PLL; predisposes to posterolateralposterolateral HNPHNPCaudaCauda EquinaEquina–– Spinal cord ends at T11Spinal cord ends at T11--L1L1–– Nerve roots extending to Nerve roots extending to intervertebralintervertebral

foramenforamen–– Lesion from T12 to Sacrum can produce Lesion from T12 to Sacrum can produce

same EMG findingssame EMG findingsMust know brachial and LMust know brachial and L--S plexus and S plexus and muscle innervationsmuscle innervations

Cauda Equina

History and Physical History and Physical ExaminationExamination

PHYSICAL EXAMPHYSICAL EXAM

Focused NeuromuscularFocused Neuromuscular–– Affected limb and contralateralAffected limb and contralateral–– If Neck symptomsIf Neck symptoms--lower limbs to look for lower limbs to look for

myelopathymyelopathy–– Cranial nervesCranial nerves-- ?CVA, MG, AIDP?CVA, MG, AIDPReduced Reflexes with Acute Spinal Reduced Reflexes with Acute Spinal ShockShock

ALGORITHMIC APPROACHALGORITHMIC APPROACHSymptomsSymptoms–– Generalized (2 or more limbs)Generalized (2 or more limbs)–– Focal (single limb)Focal (single limb)SignsSigns–– Sensory lossSensory loss–– WeaknessWeakness–– Reflexes Reflexes Not perfect taxonomyNot perfect taxonomy-- RadicsRadics and and Entrapments Entrapments

Patient Presentation

(Pain, Weakness, Gait disturbance, Sensory Symptoms, Paresthesias)

No sensory loss on Exam Sensory loss on Exam

Generalized Symptoms(With Weakness)

Generalized Symptoms(No Weakness)–Fibrositis–Polymyalgia Rheumatica

–Motor NeuronDisease

–Myopathy–Neuromuscular Junction Disorder

Focal Symptoms

–MMN–Radiculopathy–Entrapment Neuropathy –Mononeuropathy–Musculoskelatal disorder–Myofascial pain syndrome

Focal Symptoms

GeneralizedSymptoms

Reduced Reflexes–Polyneuropathy–Bilateral CR–Bilateral LSR–Cauda equina Syndr.

–Entrapment–Radiculopathy–Plexopathy–Mononeuropathy

Increased Reflexes–Cervical Myelopathy–Thoracic Myelopahty–Multiple Sclerosis–Other Myelopathies

Symptoms and EDX Study Outcome for Upper Symptoms and EDX Study Outcome for Upper Limb and Lower Limb StudiesLimb and Lower Limb Studies

Lauder et al 2000 Lauder et al 2000 AJPMRAJPMR

Symptoms had low sensitivitiesSymptoms had low sensitivitiesLow specificitiesLow specificitiesNonNon--significant Odds Ratiossignificant Odds Ratios

PHYSICAL EXAM FINDINGSPHYSICAL EXAM FINDINGS

Weakness, reflex change, or sensory loss Weakness, reflex change, or sensory loss in the in the legleg–– 33--6 times the probability of having a positive 6 times the probability of having a positive

study (study (Lauder et al, 2000 Lauder et al, 2000 AJPMR)AJPMR)–– 33--14 times the probability of having an 14 times the probability of having an

electrodiagnostically confirmed radiculopathy electrodiagnostically confirmed radiculopathy (Lauder (Lauder et al, 2000 et al, 2000 AJPMR)AJPMR)

PHYSICAL EXAM FINDINGSPHYSICAL EXAM FINDINGS

Weakness, reflex change, or sensory loss Weakness, reflex change, or sensory loss in the in the armarm–– 44--5 times the probability of having a positive 5 times the probability of having a positive

study (study (Lauder et al, 2000 Lauder et al, 2000 Arch PMR)Arch PMR)–– 22--9 times the probability of having an 9 times the probability of having an

electrodiagnostically confirmed CR electrodiagnostically confirmed CR (Lauder et al, 2000 (Lauder et al, 2000 Arch PMR)Arch PMR)

ElectrodiagnosisElectrodiagnosis

Electrodiagnostic StudiesElectrodiagnostic Studies

Nerve Conduction StudiesNerve Conduction StudiesSSEPsSSEPsF waves and H reflexesF waves and H reflexes

EMGEMG

AAEM GUIDELINES 1999 AAEM GUIDELINES 1999 Muscle and NerveMuscle and Nerve

Examine muscles representing all Examine muscles representing all myotomesmyotomesPSM localize lesion to root levelPSM localize lesion to root levelOne motor and one sensory NCSOne motor and one sensory NCS

ELECTRODIAGNOSTIC ELECTRODIAGNOSTIC TESTINGTESTING

Perform the basic tests related to Perform the basic tests related to suspected conditionsuspected conditionAdjust and modify study as data are Adjust and modify study as data are acquiredacquiredMay need serial studiesMay need serial studiesLow threshold to study contralateral limb Low threshold to study contralateral limb or upper (lower) limbor upper (lower) limb

USEFULLNESS OF USEFULLNESS OF ELECTRODIAGNOSISELECTRODIAGNOSIS

Confirm clinical suspicionConfirm clinical suspicionRaise other unsuspected diagnostic Raise other unsuspected diagnostic possibilitiespossibilitiesExclude entities on the differential Exclude entities on the differential diagnosisdiagnosisIdentify region to imageIdentify region to imageTailors other diagnostic testingTailors other diagnostic testing

Nerve Conduction StudiesNerve Conduction Studies

Sensory NCS should be normalSensory NCS should be normalMotor NCS should be normalMotor NCS should be normal–– Sometimes low amplitude with severe diseaseSometimes low amplitude with severe disease

FF--WAVESWAVESMotor axons and axonal pool at spinal Motor axons and axonal pool at spinal cord levelcord levellong pathwayslong pathwaysdifferent axons involved with each different axons involved with each responseresponseMinimal latencyMinimal latency, mean latency, dispersion, mean latency, dispersionInconsistent morphology and latencyInconsistent morphology and latencyMaximal stimulus responseMaximal stimulus responseNot helpful for radiculopathy, good screen Not helpful for radiculopathy, good screen for polyneuropathyfor polyneuropathy

HH--REFLEXESREFLEXESMonosynaptic electrical Achilles reflexMonosynaptic electrical Achilles reflexLong pathwayLong pathwayAbnormal in sciatic n. plexopathy, S1 Abnormal in sciatic n. plexopathy, S1 radicradicSubmaximalSubmaximal stimulus responsestimulus responseConsistent in latency and morphologyConsistent in latency and morphologyExtinguishes with Extinguishes with supramaximalsupramaximal stimulusstimulusOnly 50% sensitive for S1 radiculopathy but Only 50% sensitive for S1 radiculopathy but high specificity 91% high specificity 91% May help with L5 May help with L5 vsvs S1S1Better screen for polyneuropathyBetter screen for polyneuropathy

ElectromyographyElectromyography

Most important test for suspected Most important test for suspected radiculopathyradiculopathyGood confirmatory testGood confirmatory testHelps clarify relevance of imaging findings Helps clarify relevance of imaging findings

EDX CRITERIA FOR EDX CRITERIA FOR RADICULOPATHYRADICULOPATHY

Abnormalities in 2 or more musclesAbnormalities in 2 or more muscles–– Same nerve rootSame nerve root–– Different peripheral nervesDifferent peripheral nervesMuscle innervated by adjacent nerve roots Muscle innervated by adjacent nerve roots are normalare normalOther conditions are excludedOther conditions are excluded

EMG SENSITIVITIES FOR EMG SENSITIVITIES FOR LUMBOSACRAL LUMBOSACRAL

RADICULOPATHIESRADICULOPATHIESVaries widelyVaries widelyRanges from about 50% to 80%Ranges from about 50% to 80%Various diagnostic standardsVarious diagnostic standards

605586644956798478

Clinical+imaging HNPClinicalClinicalClinicalClinicalSurgically provenSurgically provenClinical an imagingMyelography and CT

4247100955710020610019

Lumbosacral radiculopathy Weber and Albert [55] Nardin et al [28]Kuruoglu et al [8]Khatri et al [56]Tonzola et al [57]Schoendinger [58]Knutsson [45]Young et al [3]Linden and Berlit [3]

EMG sensitivity %

Gold standardSample size

Study

EMG SENSITIVITY FOR EMG SENSITIVITY FOR CERVICAL CERVICAL

RADICULOPATHIESRADICULOPATHIES

Varies widelyVaries widelyAbout 50% to 70%About 50% to 70%Usually clinical and/or Usually clinical and/or myelographicmyelographic

9288

Clinical+myelogramClinical+myelogram

6864

Lumbosacral spinal stenosis

Hall et al [46]Johnsson et al [59]

61676771509551

ClinicalIntraoperativeClinical+myelogramClinicalClinical/radiographicClinicalClinical

187724142020

108

Cervical radiculopathyBerger et al [60]Partanen et al [61]Leblhuber et al [9]So et al [62]Yiannikas et al [18]

Tackman and Radu [15]Hong et al [63]

EMG sensitivity %

Gold standardSample size

Study

LUMBAR SPINAL STENOSISLUMBAR SPINAL STENOSIS

EMG findings are less well studied than EMG findings are less well studied than for single level radiculopathiesfor single level radiculopathiesClinical entity with various clinical Clinical entity with various clinical presentationspresentationsImaging is vital, but has gradations of Imaging is vital, but has gradations of severityseverity–– Dynamic aspects of spinal canal, narrow with Dynamic aspects of spinal canal, narrow with

extension extension –– Boney spurs + facet hypertrophy + ligament Boney spurs + facet hypertrophy + ligament

hypertrophy + HNPhypertrophy + HNP

EMG in Lumbosacral Spinal EMG in Lumbosacral Spinal StenosisStenosis

Hall and Colleagues (1985)Hall and Colleagues (1985)68 patients68 patients--myelographicallymyelographicallyproven/surgically confirmed Lumbar proven/surgically confirmed Lumbar stenosis.stenosis.PseudoclaudicationPseudoclaudication (94%)(94%)Numbness (63%)Numbness (63%)Weakness (43%)Weakness (43%)Bilateral symptoms (68%)Bilateral symptoms (68%)

EMG in Lumbosacral Spinal EMG in Lumbosacral Spinal StenosisStenosis

Hall and colleagues (1985)Hall and colleagues (1985)--cont.cont.EMG positive in 34 of 37 patients EMG positive in 34 of 37 patients studiedstudied–– 11 bilateral EMG findings with paraspinal 11 bilateral EMG findings with paraspinal

fibs fibs –– 17 bilateral EMG findings without 17 bilateral EMG findings without

paraspinal fibrillationsparaspinal fibrillations–– 6 showed single root EMG findings 6 showed single root EMG findings

(bilateral in 3 cases)(bilateral in 3 cases)Paraspinal findings often lacking on Paraspinal findings often lacking on EMGEMG““EMG more helpful than physical examEMG more helpful than physical exam””

SPINAL STENOSIS SPINAL STENOSIS vsvs POLYNEUROPATHYPOLYNEUROPATHYAdamovaAdamova B, B, VohankaVohanka S, S, DusekDusek L. Differential diagnostics in patients L. Differential diagnostics in patients with mild lumbar spinal with mild lumbar spinal stenosis:thestenosis:the contributions and limits of various contributions and limits of various

tests. tests. EurEur Spine J. 2003;12:190Spine J. 2003;12:190--196.196.

Difficult Difficult DDxDDxThree groups: Three groups: –– 29 persons with imaging confirmed clinical 29 persons with imaging confirmed clinical

mild lumbar spinal stenosis,mild lumbar spinal stenosis,–– 24 subjects had diabetic polyneuropathy, 24 subjects had diabetic polyneuropathy, –– 25 healthy age25 healthy age--matched volunteers matched volunteers

participated participated

SPINAL STENOSIS SPINAL STENOSIS vsvs POLYNEUROPATHYPOLYNEUROPATHY

SuralSural sensory amplitudes distinguished sensory amplitudes distinguished the diabetic polyneuropathy groupthe diabetic polyneuropathy group–– 4.2microvolts or less was found in 47% of 4.2microvolts or less was found in 47% of

diabetic patients and only 17% of stenosis diabetic patients and only 17% of stenosis patients). patients).

Ulnar F wave was prolonged in Ulnar F wave was prolonged in polyneuropathy patientspolyneuropathy patientsRadial SNAP was reduced in Radial SNAP was reduced in polyneuropathy patients. polyneuropathy patients. Sensory testing and FSensory testing and F--wave testing in the wave testing in the involved extremity and an upper limbinvolved extremity and an upper limb

AANEM AANEM (England et al: (England et al: Muscle & NerveMuscle & Nerve 2005)2005)

Electrodiagnostic findings critical Electrodiagnostic findings critical SuralSural sensorysensory and and peroneal motorperoneal motor nerve nerve conductions are the most sensitive for conductions are the most sensitive for detecting a detecting a distal symmetric distal symmetric polyneuropathypolyneuropathyWill not exclude all Will not exclude all polyneuropathiespolyneuropathies..

Case 1: Elderly patient with chronic low back pain, Case 1: Elderly patient with chronic low back pain, right leg pain and some numbness in both feetright leg pain and some numbness in both feet

NormalNormalPSM (Multiple levels)PSM (Multiple levels)

RIGHTRIGHTSIX MUSCLE SCREENSIX MUSCLE SCREEN

2+ fibs2+ fibsMedial Medial gastrocgastroc (S1(S1--S2)S2)

NormalNormalTFL(L5TFL(L5--S1)S1)

NormalNormalAnterior Anterior TibialisTibialis (L4(L4--L5)L5)

NormalNormalVastusVastus Med (L3Med (L3--L4)L4)

NormalNormalPeroneusPeroneus longus(L5longus(L5--S1)S1)

Case 1: Study more musclesCase 1: Study more muscles

NormalNormalGluteus Maximus(L5Gluteus Maximus(L5--S1)S1)

2+ fibs2+ fibsFlexor Flexor DigitorumDigitorum BrevisBrevis (S1(S1--S2) Foot muscleS2) Foot muscle


RIGHTRIGHTSIX MUSCLE SCREEN PlusSIX MUSCLE SCREEN Plus






Case 1: Study more musclesCase 1: Study more muscles

NormalNormal

2+ fibs2+ fibs

2+ fibs2+ fibs

NormalNormal

NormalNormal

NormalNormal

NormalNormal

NormalNormal

RightRight

Gluteus Maximus(L5Gluteus Maximus(L5--S1)S1)

Flexor Flexor DigitorumDigitorum BrevisBrevis (S1(S1--S2) Foot muscleS2) Foot muscle


LeftLeftSIX MUSCLE SCREEN PlusSIX MUSCLE SCREEN Plus






Case 1Case 1

Suggestive of bilateral sciatic Suggestive of bilateral sciatic neuropathies, polyneuropathy, or bilateral neuropathies, polyneuropathy, or bilateral S1 radiculopathies.S1 radiculopathies.Remember that PSM in lumbar Spinal Remember that PSM in lumbar Spinal stenosis may be normalstenosis may be normalWhat do you do to sort this out?What do you do to sort this out?

Case 1 Nerve conductionsCase 1 Nerve conductions

SuralSural sensory responses absent sensory responses absent bilaterally.bilaterally.In this case:In this case:

––PolyneuropathyPolyneuropathy–– Bilateral sciatic neuropathies Bilateral sciatic neuropathies –– unlikelyunlikely–– Bilateral lumbosacral plexopathies Bilateral lumbosacral plexopathies –– unlikelyunlikely–– Bilateral S1 radiculopathies less likely.Bilateral S1 radiculopathies less likely.What else?What else?

Case 1 Case 1 More NCSMore NCS

Peroneal motor studies low normal CMAPPeroneal motor studies low normal CMAPEMG of right FDI (in hand) was + for fibsEMG of right FDI (in hand) was + for fibsRadial sensory was low in amplitude and Radial sensory was low in amplitude and slightly prolonged in latencyslightly prolonged in latency

Case 1 SummaryCase 1 Summary

Abnormal study: Abnormal study:

Findings suggest:Findings suggest:–– Motor and sensory primarily axonal Motor and sensory primarily axonal

polyneuropathypolyneuropathy..

COMPARING SURGICAL AND EMG FINDINGS IN LSRCOMPARING SURGICAL AND EMG FINDINGS IN LSRTSAO, LEVIN AND BODNER Muscle and Nerve 2003TSAO, LEVIN AND BODNER Muscle and Nerve 2003

45 patients with imaging, EMG and 45 patients with imaging, EMG and surgically confirmed LSRsurgically confirmed LSRLittle overlap between L2Little overlap between L2--L4 , L5, and S1 L4 , L5, and S1 RadiculopathiesRadiculopathiesTibialisTibialis anterior L5anterior L5GastrocnemiusGastrocnemius S1S1Biceps S1Biceps S1

IDENTIFICATIONIDENTIFICATION

Different concept from SensitivityDifferent concept from SensitivityConditional probabilityConditional probability–– How much testing, given that EDX testing will How much testing, given that EDX testing will

identify a disorderidentify a disorderIf a disorder can be confirmed by EDX, If a disorder can be confirmed by EDX, how much testing is necessary to how much testing is necessary to recognize this possibilityrecognize this possibility

CAVEATS AND LIMITATIONSCAVEATS AND LIMITATIONS

Needle EMG is not an effective screening Needle EMG is not an effective screening test alone (Radiculopathy)test alone (Radiculopathy)MRI better screen for structural causesMRI better screen for structural causesBetter specificityBetter specificity-- Diagnosis confirmationDiagnosis confirmationMotor Axonal loss necessary for fibsMotor Axonal loss necessary for fibs


Some cannot be confirmed by EMGSome cannot be confirmed by EMG–– Sensory roots affectedSensory roots affected–– No axonal lossNo axonal lossNo amount of muscles will help confirmNo amount of muscles will help confirmNeed to abbreviate study in this scenarioNeed to abbreviate study in this scenarioEnough muscles to reach this conclusionEnough muscles to reach this conclusionWhen can a needle EMG be stopped with a When can a needle EMG be stopped with a confidence that there is a low probability of confidence that there is a low probability of missing a confirmable radiculopathymissing a confirmable radiculopathy

PROSPECTIVE LSR PROSPECTIVE LSR IDENTIFICATIONIDENTIFICATION

Dillingham, et al, Dillingham, et al, AmJPM&RAmJPM&R, 2000, 2000Multicenter studyMulticenter study102 patients with EDX LSR102 patients with EDX LSRStandard screen with 11 musclesStandard screen with 11 musclesFive muscles with PSM: 94Five muscles with PSM: 94--98%98%Six muscles with PSM: 98Six muscles with PSM: 98--100%100%Without PSM eight muscles; 90%Without PSM eight muscles; 90%

93878789929193

9999989910099100

Six muscles with paraspinals

ATIB, PTIB, MGAS, PSM, VMED, TFLVMED, LGAS, PTIB, PSM, SHBF, MGAS

VLAT, TFL, LGAS, PSM, ATIB, SHBFADD, MGAS, PTIB, PSM, VLAT, SHBF

VMED, ATIB, PTIB, PSM, SHBF, MGASVMED, TFL, LGAS, PSM, ATIB, PTIB

ADD, MGAS, PTIB, PSM, ATIB, SHBF

78706279

89837988

Six muscles without paraspinals

ATIB, PTIB, MGAS, RFEM, SHBF, LGASVMED, TFL, LGAS, PTIB, ADD, MGAS

VLAT, SHBF, LGAS, ADD, TFL, PTIBADD, TFL, MGAS, PTIB, ATIB, LGAS

SpontaneousActivity (%)

Neuropathic(%)

Screen

Six-muscle screen identification of patients with lumbosacral radiculopathies

PROSPECTIVE CERVICAL PROSPECTIVE CERVICAL RADICULOPATHY RADICULOPATHY IDENTIFICATIONIDENTIFICATION

Dillingham, et.al, Dillingham, et.al, AmJPM&RAmJPM&R, 2000, 2000MulticenterMulticenter--five institutionsfive institutionsStandard ScreenStandard Screen101 patients with EDX CR101 patients with EDX CRsix muscles with PSM: 94six muscles with PSM: 94--99%99%Seven muscles with PSM: 96Seven muscles with PSM: 96--100%100%Without PSM: eight muscles 92Without PSM: eight muscles 92--95%95%

8383757577777979

9999969694949898

With With paraspinalsparaspinalsDeltDelt, , trictric, PT, APB, EDC, PSM, PT, APB, EDC, PSMBicBic, , trictric, EDC, FDI, FCU, PSM, EDC, FDI, FCU, PSMDeltDelt, EDC, FDI, PSM, FCU, , EDC, FDI, PSM, FCU, trictricBicBic, FCR, APB, PT, PSM, , FCR, APB, PT, PSM, trictric

6666555564646464

9393878789899494

Without Without paraspinalsparaspinalsDeltDelt, APB, FCU, triceps, PT, FCR, APB, FCU, triceps, PT, FCRBicBic, , trictric, FCU, EDC, FCR, FDI, FCU, EDC, FCR, FDIDeltDelt, , trictric, EDC, FDI, FCR, PT, EDC, FDI, FCR, PTBicBic, , trictric, EDC, PT, APB, FCU, EDC, PT, APB, FCU

Spontaneous Spontaneous activity %activity %

NeuropathicNeuropathic %%Muscle screenMuscle screen

SixSix--muscle screen identifications of patients with cervical muscle screen identifications of patients with cervical radiculopathiesradiculopathies

““ To minimize harm, six in the To minimize harm, six in the leg and six in the armleg and six in the arm””

Suspected Radiculopathy

–Six muscles (with PSM)-lumbar screen–Six muscles (with PSM)-cervical screen

If one muscle is positive,

expand studyDetermine if EMG reflects;1) Radiculopathy (which level),

2) Entrapment neuropathy,

3) Generalized condition, or

4) Findings that are of uncertain relevance.

If all muscles negative, stop

EMG exam in this limbThe patient will not have an

electrodiagnostically confirmable radiculopathy.

They may;

1) not have radiculopathy, or

2) have a radiculopathy but you will not confirm this with EMG. Other diagnostic tests must be utilized such as MRI or SNRB.

Case 2 Person with sciatica for two months. Normal Case 2 Person with sciatica for two months. Normal strength, reflexes, and sensation, strength, reflexes, and sensation, +SLR+SLR. .

1+ fibs1+ fibsLumbar PSM (Multiple roots)Lumbar PSM (Multiple roots)

NormalNormalTensor Fascia Tensor Fascia LataLata (L5(L5--S1)S1)

NormalNormalSH of Biceps Femoris(L5SH of Biceps Femoris(L5--S1)S1)

NormalNormalMedial Medial GastrocGastroc (S1(S1--S2)S2)

2+ fibs2+ fibsTibialisTibialis Anterior (L4Anterior (L4--L5)L5)

NormalNormalVastusVastus Medialis(L3Medialis(L3--L4)L4)

FINDINGSFINDINGSSIX MUSCLE SCREENSIX MUSCLE SCREEN

Case 2 Additional muscles after Six muscle screen.Case 2 Additional muscles after Six muscle screen.

NormalNormalLateral Gastroc(S1Lateral Gastroc(S1--S2)S2)

1+ fibs1+ fibsTibialisTibialis Posterior(L5Posterior(L5--S1)S1)

NormalNormalAdductor Adductor LongusLongus (L3(L3--L4)L4)

1+ fibs1+ fibsLumbar PSM (Multiple roots)Lumbar PSM (Multiple roots)NormalNormalTensor Fascia Tensor Fascia LataLata (L5(L5--S1)S1)NormalNormalSH of Biceps Femoris(L5SH of Biceps Femoris(L5--S1)S1)

NormalNormalMedial Medial GastrocGastroc (S1(S1--S2)S2)

2+ fibs2+ fibsTibialisTibialis Anterior (L4Anterior (L4--L5)L5)

NormalNormalVastusVastus Medialis(L3Medialis(L3--L4)L4)FINDINGSFINDINGSSIX MUSCLES SIX MUSCLES PLUS MOREPLUS MORE

Case 2 ConclusionsCase 2 Conclusions

Abnormal StudyAbnormal StudyFinish it; Finish it; {{suralsural S. and peroneal M. NCS were normal}S. and peroneal M. NCS were normal}

Findings suggest:Findings suggest:

––L5 lumbosacral radiculopathyL5 lumbosacral radiculopathywith recent (acute) motor axonal loss.with recent (acute) motor axonal loss.

Recommendations:Recommendations:–– Consider imaging the lumbar spine if not Consider imaging the lumbar spine if not

already pursued.already pursued.

Case 3: 49 Case 3: 49 y/oy/o with right arm with right arm pain,proximalpain,proximalweakness, and hand numbness for 3 months. 3/5 weakness, and hand numbness for 3 months. 3/5

shoulder abduction and ER, otherwise normal shoulder abduction and ER, otherwise normal strength, reflexes, sensationstrength, reflexes, sensation

NormalNormalCervical Cervical ParaspinalsParaspinals

NormalNormalAPBAPB

NormalNormalFDIFDI

NormalNormalEDCEDC

NormalNormalTricepsTriceps

3+ fibs, CRD3+ fibs, CRDDeltoidDeltoid

Right side Right side SIX MUSCLE SCREENSIX MUSCLE SCREEN

Case 3: More EMGCase 3: More EMG

2+ fibs2+ fibsInfraspinatusInfraspinatus

2+ 2+ fibs,CRDfibs,CRDBicepsBiceps

NormalNormalCervical Cervical ParaspinalsParaspinals

NormalNormalAPBAPB

NormalNormalFDIFDI

NormalNormalEDCEDC

NormalNormalTricepsTriceps

3+ fibs, CRD3+ fibs, CRDDeltoidDeltoid

RightRightSIX MUSCLE SCREENSIX MUSCLE SCREEN

Case 3: More EMGCase 3: More EMG

NormalNormalNormalNormalAnterior Anterior tibialistibialisNormalNormalNormalNormalCervical Cervical ParaspinalsParaspinals

NormalNormalNormalNormalNormalNormalnormalnormal

LeftLeft

2+ fibs2+ fibsInfraspinatusInfraspinatus2+ 2+ fibs,CRDfibs,CRDBicepsBiceps

NormalNormalAPBAPBNormalNormalFDIFDINormalNormalEDCEDCNormalNormalTricepsTriceps

3+ fibs, CRD3+ fibs, CRDDeltoidDeltoidRightRightSIX MUSCLE SCREENSIX MUSCLE SCREEN

Case 3 Case 3

NCS of Median and Ulnar Motor and NCS of Median and Ulnar Motor and Sensory were normal Sensory were normal Radial sensory normalRadial sensory normalLAC normalLAC normalNormal right median FNormal right median F--WaveWave

Case 3: SummaryCase 3: Summary

Abnormal StudyAbnormal StudyFindings suggest:Findings suggest:–– Right Upper Trunk Brachial PlexopathyRight Upper Trunk Brachial Plexopathy OR OR

Right C5Right C5--C6 Cervical RadiculopathyC6 Cervical Radiculopathy

–– Suggest imaging of both the right brachial Suggest imaging of both the right brachial plexus and cervical spineplexus and cervical spine

LUMBOSACRAL PSM EMG: LUMBOSACRAL PSM EMG: PREVALENCE OF FIBRILLATIONS IN NORMALSPREVALENCE OF FIBRILLATIONS IN NORMALS

DumitruDumitru, Diaz, and King (2001), Diaz, and King (2001)Prospective study 50 Prospective study 50 normalsnormals L4/L5 levelsL4/L5 levelsMonopolarMonopolar needle, recorded potentialsneedle, recorded potentialsExamined firing rate and rhythmExamined firing rate and rhythmFibrillation inclusion criteria; Fibrillation inclusion criteria; regular firing regular firing raterate4% false positive fibrillations in paraspinal 4% false positive fibrillations in paraspinal muscles muscles

CERVICAL PSMCERVICAL PSM(Date et al (Date et al Muscle &NerveMuscle &Nerve 2006)2006)

Cervical PSM in Cervical PSM in assymptomaticassymptomatic personspersonsC56 and C67 areas BilaterallyC56 and C67 areas BilaterallyFour quadrantsFour quadrantsMUST BE REGULARLY firing for 1s or MUST BE REGULARLY firing for 1s or moremoreMonopolarMonopolar needleneedle12% in 66 showed 12% in 66 showed PSWsPSWs none showed none showed fibsfibs

FALSE NEGATIVE (no fibs or PSW) FALSE NEGATIVE (no fibs or PSW) ON EMG IN RADICULOPATHYON EMG IN RADICULOPATHY

Sensory root involvement onlySensory root involvement onlyMotor root involvement without axonal Motor root involvement without axonal lossloss–– DemyelinationDemyelination, conduction block, conduction blockMotor axonal loss balanced with Motor axonal loss balanced with reinnervationreinnervation

MUSCLE INJURY CAUSING MUSCLE INJURY CAUSING FIBRILLATIONSFIBRILLATIONS

PartanenPartanen et al 1982 et al 1982 Muscle & Muscle & NerveNerve

Study of 43 patients with EMG before Study of 43 patients with EMG before and after Muscle biopsyand after Muscle biopsy50% had fibrillations 650% had fibrillations 6--7 days after 7 days after biopsybiopsyAt 16 days 100% had fibrillationsAt 16 days 100% had fibrillationsFibrillations persisted up to 11 months Fibrillations persisted up to 11 months post biopsypost biopsy

Symptom Duration is not Related to Symptom Duration is not Related to Fibrillation PotentialsFibrillation Potentials

Long held notion in the electrodiagnostic Long held notion in the electrodiagnostic literature regarding radiculopathiesliterature regarding radiculopathiesParaspinal (PSM) muscles Paraspinal (PSM) muscles denervatedenervate first, first, then more distalthen more distalReinnervation thought to occur first in Reinnervation thought to occur first in PSM then distalPSM then distalNo evidence to support this modelNo evidence to support this model

SYMPTOM DURATION AND EMG FIBRILLATIONSSYMPTOM DURATION AND EMG FIBRILLATIONS

Dillingham et al, 1998, 1998, 2000; Pezzin et al 1999Dillingham et al, 1998, 1998, 2000; Pezzin et al 1999

Four separate investigationsFour separate investigations–– Two retrospective (Cervical and Lumbosacral)Two retrospective (Cervical and Lumbosacral)–– Two prospective (Cervical and Lumbosacral)Two prospective (Cervical and Lumbosacral)Probability of finding fibrillations in a Probability of finding fibrillations in a muscle (proximal or distal) was not related muscle (proximal or distal) was not related to symptom duration.to symptom duration.Simplistic model of symptom duration Simplistic model of symptom duration doesndoesn’’t explain the complex t explain the complex pathophysiology of radiculopathies and pathophysiology of radiculopathies and their EMG correlatestheir EMG correlates

Natural History of Natural History of RadiculopathyRadiculopathy


Cervical radiculopathy in absence of Cervical radiculopathy in absence of myelopathymyelopathy-- good outcomes with good outcomes with conservative careconservative careLumbosacral radiculopathy, without Lumbosacral radiculopathy, without caudacaudaequinaequina symptomssymptoms--good outcomes with good outcomes with conservative careconservative care

CERVICAL RADICULOPATHY CERVICAL RADICULOPATHY OUTCOMEOUTCOME

SaalSaal, , SaalSaal, , YurthYurth. Spine 1996. Spine 1996–– 26 patients with Cervical HNP26 patients with Cervical HNP–– TxTx: Pain meds, cervical traction, : Pain meds, cervical traction,

epidurals if poor pain controlepidurals if poor pain control–– 24 of 26 achieved successful 24 of 26 achieved successful

outcomesoutcomes

PROGRESSION OF CERVICAL SPONDYLOTIC CORD PROGRESSION OF CERVICAL SPONDYLOTIC CORD COMPRESSIONCOMPRESSION

BednarikBednarik et al Spine 2004et al Spine 2004

66 patients with MRI mild cervical cord 66 patients with MRI mild cervical cord compression but no signs of compression but no signs of myelopathymyelopathyFollowed for 2 yearsFollowed for 2 years20% developed signs of 20% developed signs of myelopathymyelopathy

PROGRESSION OF CERVICAL SPONDYLOTIC CORD PROGRESSION OF CERVICAL SPONDYLOTIC CORD COMPRESSIONCOMPRESSION

BednarikBednarik et al Spine 2004et al Spine 2004

Symptomatic cervical radiculopathy and Symptomatic cervical radiculopathy and EMG showing motor axonal loss in 2 EMG showing motor axonal loss in 2 myotomes predicted with myotomes predicted with 90% accuracy90% accuracythose who progressed to symptomatic those who progressed to symptomatic myelopathymyelopathy..Odds ratio 12.5 (p<0.001) for EMG Odds ratio 12.5 (p<0.001) for EMG Odds ratio 36.9 (p<0.001)for clinical Odds ratio 36.9 (p<0.001)for clinical radiculopathy (motor or sensory signs)radiculopathy (motor or sensory signs)

BACK SURGERY RATES IN BACK SURGERY RATES IN THE UNITED STATESTHE UNITED STATES

CherkinCherkin et al, Spine 1994et al, Spine 1994United StatesUnited States–– 5 times that of England5 times that of England–– Increased linearly with increasing number Increased linearly with increasing number

of surgeonsof surgeons

LUMBAR DISCECTOMY LUMBAR DISCECTOMY PREDICTORS OF OUTCOMESPREDICTORS OF OUTCOMES

Spengler, et al, JBJS 1990Spengler, et al, JBJS 1990Developed scale for surgical candidate Developed scale for surgical candidate selectionselection100 points100 points–– Neurological Signs (EMG) (25)Neurological Signs (EMG) (25)–– Sciatic Tension Signs (25) Sciatic Tension Signs (25) –– MMPI (25)MMPI (25)–– Lumbar Lumbar MyelogramMyelogram or CT (25)or CT (25)

Lumbar Discectomy OutcomesLumbar Discectomy Outcomes

Spengler et al JBJS 1990Spengler et al JBJS 1990–– Preoperative assessment of probability Preoperative assessment of probability

of good outcomesof good outcomes–– Patients with < 50 points: No surgeryPatients with < 50 points: No surgery–– Best outcomes are >80 points Best outcomes are >80 points

NATURAL HISTORY OF NATURAL HISTORY OF SCIATICASCIATICA

Bush et al, Spine 1992Bush et al, Spine 1992165 patients with Sciatica165 patients with Sciatica–– 86% made satisfactory recovery86% made satisfactory recovery–– 76% 76% HNPsHNPs resolved on f/u MRIresolved on f/u MRITxTx consisted of pain meds, epiduralsconsisted of pain meds, epidurals

ConclusionsConclusions

Electrodiagnosis important adjunctive and Electrodiagnosis important adjunctive and confirmatory testconfirmatory testExcludes confounding diagnoses Excludes confounding diagnoses Has important limitations you need to Has important limitations you need to understandunderstand

evaluating the patient with suspected radiculopathy · pll; predisposes to posterolateral hnp cauda...

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