Reflex & ConductionReflex & Conduction

Liu, An-Bang M.D., M.M.Sci.Liu, An-Bang M.D., M.M.Sci.Department of Neurology, Tzu Chi Medical Center, Hualien, TaiwanDepartment of Neurology, Tzu Chi Medical Center, Hualien, Taiwan

Division of Neuromuscular Research and Neurogenetics,Division of Neuromuscular Research and Neurogenetics,Tzu Chi Neuro-Medical Scientific Center, Hualien, TaiwanTzu Chi Neuro-Medical Scientific Center, Hualien, Taiwan

The Clinical Application of NeuroscienceThe Clinical Application of Neuroscience

The Problem of Neurology Is

Montreal NeurologicalInstitute & Hospital

to Understand Human Himself

Wilder Penfield

Principles of Electrophysiologic StudyPrinciples of Electrophysiologic Study

Instruments & Instruments & IntroductionIntroduction

ElectrodeElectrodeAnodeAnodeCathodeCathodeAmplitudeAmplitudeFrequencyFrequencyCalibrationCalibrationFilterFilter

General DevicesGeneral Devices

ElectrodesElectrodes

StimulatorStimulator

Nerve Conduction StudyNerve Conduction Study

Compound Motor Action PotentialCompound Motor Action Potential

latency

duration

amplitude

amplitude

Nerve Conduction StudyNerve Conduction Study

Nerve Action PotentialsNerve Action Potentials

Sensory Action PotentialsSensory Action Potentials

Structures of Peripheral NerveStructures of Peripheral Nerve

Nerve ConductionNerve Conduction

Temporal DispersionTemporal Dispersion

F-WavesF-Waves

Tested NervesTested Nerves

Median nerveMedian nerve CMAPs and SAPsCMAPs and SAPs

Ulnar nerveUlnar nerve CMAPs and SAPsCMAPs and SAPs

Tibial nerveTibial nerve CMAPs, H-reflexCMAPs, H-reflex

Peroneal nervePeroneal nerve CMAPsCMAPs

Sural nerveSural nerve SAPsSAPs

Median NerveMedian Nerve

Median NerveMedian Nerve

Nerve Conduction VelocityNerve Conduction Velocity

NCV=NCV=distance/distance/latencylatency

45-55 m/Sec45-55 m/Sec

Ulnar NerveUlnar Nerve

Ulnar NerveUlnar Nerve

Radial NerveRadial Nerve

Radial Nerve (SAP)Radial Nerve (SAP)

Peroneal NervePeroneal Nerve

Peroneal NervePeroneal Nerve

Tibial NerveTibial Nerve

Tibial NerveTibial Nerve

Sural Nerve (SAP)Sural Nerve (SAP)

H-reflexH-reflex

H-ReflexH-Reflex

The H-reflex can normally be seen in many muscles but is easily obtained in the soleus muscle (with posterior tibial nerve stimulation at the popliteal fossa), the flexor carpi radialis muscle (with median nerve stimulation at the elbow), and the quadriceps (with femoral nerve stimulation).

H-ReflexH-Reflex

The H-reflex can normally be seen in many muscles but is easily obtained in the soleus muscle (with posterior tibial nerve stimulation at the popliteal fossa), the flexor carpi radialis muscle (with median nerve stimulation at the elbow), and the quadriceps (with femoral nerve stimulation).

ApplicationsApplications

To confirm the diagnosis of neuropathyTo confirm the diagnosis of neuropathyTo evaluate the possible pathological To evaluate the possible pathological

changes of neuropathychanges of neuropathyTo detect and evaluate the site of To detect and evaluate the site of

conduction block of entrapment neuropathyconduction block of entrapment neuropathyTo insure the diagnosis of multi-focal To insure the diagnosis of multi-focal

conduction block motor neuropathyconduction block motor neuropathy

ContraindicationsContraindications

Facial NerveFacial Nerve

Recording sites: Place the active recording over the orbicularis oris at the corner of the mouth, over the orbicularis oculi on the outer canthus of the eye, over the frontalis in the forehead, or over the nasalis muscle on the nasolabial fold. Place the reference electrode on the nose. Either a needle or surface electrode may be used for recording.

Blink ReflexBlink Reflex

Blink ReflexBlink Reflex

Blink ReflexBlink Reflex

ApplicationsApplications

To evaluate brainstem dysfunctionTo evaluate brainstem dysfunction

ElectromyographyElectromyography

EMG-NeedlesEMG-Needles

Spontaneous DischargesSpontaneous Discharges

Normal Motor Unit PotentialsNormal Motor Unit Potentials

Motor Unit PotentialsMotor Unit Potentials

RecruitmentRecruitment

Acute Denervational ChangesAcute Denervational Changes

fibrillationpositive sharp waves

Positive Sharp WavesPositive Sharp Waves

Polyphasic WavesPolyphasic Waves

Giant WavesGiant Waves

Myopathic DischargesMyopathic Discharges

Short-duration small-amplitude polyphasic waves

Polyphasic WavesPolyphasic Waves

Positive Sharp Waves

Positive Sharp Waves

MyotomesMyotomes

Anterior TibialisAnterior Tibialis

GastrocnemiusGastrocnemius

Abductor Pollicis BrevisAbductor Pollicis Brevis

First Dorsal InterosseusFirst Dorsal Interosseus

Paraspinalis (lower lumbar)Paraspinalis (lower lumbar)

ApplicationsApplications

To localize and stage the lesion of neuropatTo localize and stage the lesion of neuropathy or radiculopathyhy or radiculopathy

To differentiate neuropathy from myopathyTo differentiate neuropathy from myopathyTo identify neuromuscular junction disordeTo identify neuromuscular junction disorde

rsrsTo confirm the diagnosis of motor neuron diTo confirm the diagnosis of motor neuron di

seasesease

Motor Evoked PotentialsMotor Evoked Potentials

Brainstem Auditory Brainstem Auditory Evoked PotentialEvoked Potential

Somatosensory Evoked PotentialsSomatosensory Evoked Potentials