Genomläst 2007-01-31/meg
MOTOR NERVE CONDUCTION STUDIESDepartment of clinical neurophysiology
University HospitalUppsala, Sweden
by
Björn Falck, Erik Stålberg and Lena Eriksson
version 16-12-1997
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METHODS FOR MOTOR NERVE CONDUCTION STUDIES
N. MEDIANUS
Position of limb: Patient supine, sitting or reclining. Elbow extended or slightly flexed, forearm
supinated, (palm of the hand facing upward), wrist in a neutral position. Fingers in a neutral, relaxed
position, slightly flexed.
Type of recording electrodes: Surface plate electrodes.
Placement of recording electrode: At the midpoint of a line drawn from the first metacarpo-phalangeal
joint and the insertion of the tendon of m. flexor carpi radialis.
Placement of reference electrode: At the distal interphalangeal joint of the thumb
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Palm
Wrist, 80 mm proximal to the recording electrode (measured obliquely, along the course of the nerve)
Elbow
Upper arm
Supraclavicular region
Anomalies: The Martin - Gruber anomaly occurs in many normal subjects. If a Martin -Gruber
anomaly is present, special techniques are required to measure the conduction velocity.
Picture of MCS n Medianus
N. MEDIANUS, H-reflex
Position of limb: Patient supine, sitting or reclining. Elbow extended or slightly flexed, forearm
supinated.
Type of recording electrodes: Surface plate electrodes.
Placement of recording electrode: Over m. flexor carpi radialis 6-8 cm distal to the medial epicondyle.
Placement of reference electrode: Over the lateral epicondyle.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation site: Elbow.
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N. INTEROSSEUS ANTERIOR
Position of limb: Patient supine, sitting or reclining. Elbow extended or slightly flexed. Forearm
pronated (palm facing downwards).
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: In the middle of the ventral side of the forearm 3 cm above the distal
ulnar styloid process.
Position of the reference electrode: Over the lateral side of the metacarpophalangel joint of digit I.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation site: Elbow. If the two sides will be compared make sure that the distance between the
stimulating cathode and recording electrode is identical.
Picture of MCS n Interosseus anterior
N. ULNARIS
Position of limb: Patient supine, sitting or reclining. Elbow slightly flexed (15### - 30###). The
forearm is rotated outwards, the palm faces upwards. The fingers are relaxed in a neutral position,
slightly flexed.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: At the midpoint of a line between the fifth metacarpo-phalangeal joint
and the piriform bone.
Position of reference electrode: On the middle phalanx of digit V.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Wrist, 80 mm proximal to the recording electrode
Middle of forearm. Below elbow, around 10-15 mm distal to the medial epicondylus
Above elbow, around 90-120 mm proximal to medial epicondylus
Axilla
Supraclavicular region
Anomalies: Martin - Gruber anomaly.
Picture of MCS n Ulnaris
N. RADIALIS – OBS, se istället metod n. Radialis utanför detta dokument!
Position of limb: Patient supine, sitting or reclining. Elbow extended, palm facing downward.
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Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over the middle of m.extensor indicis propri. On the dorsal side of
the forearm 5-7 cm proximal to the ulnar styloid process.
Position of reference electrode: Over the fifth metacarpal bone.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Forearm. At the junction of the proximal and middle third of the forearm, in the groove between
m.extensor digitorum communis and m.extensor carpi ulnaris
Elbow, between the tendon of m.biceps brachii and m.brachioradialis.
Upper arm, in the radial groove
Axilla
Supracalaicular region.
Note: It may be necessary to use needle stimulation electrodes in the forearm and elbow. At these
points the nerve is located below muscles and may be difficult to stimulate. Calipers should be used
to measure the distance in the segment from the elbow to the forearm.
Picture of MCS n Radialis
N. MUSCULOCUTANEUS
Position of limb: Patient supine, sitting or reclining.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over anterior side of the middle of the long head of m.biceps brachii.
Position of reference electrode: Over the lateral epicondylus.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Axilla, just above the tendon of m.latissimus dorsi
Supraclavicular region
Measurement of distance: For accurate distance measurement it is advisable to use calipers.
Picture of MCS n Musculocutaneus
N. AXILLARIS
Position of limb: Patient supine, sitting or reclining. Elbow extended and forearm supinated.
Type of recording electrodes: Surface plate electrodes.
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Position of recording electrode: In the middle of the lateral side of m. deltoideus.
Position of reference electrode: In the lower third of the upper arm.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites: Supraclavicular region.
Picture of MCS n Axillaris
N. SUPRASCAPULARIS
Position of patient and limb: Patient prone, arm along the side of the trunk.
Type of recording electrodes: Needle or surface electrodes.
Position of recording electrode: M.infraspintus
Type of stimulating electrodes: Surface electrodes on a fixed bar or near nerve needle electrodes
Stimulation sites: Supraclavicular region
Picture of MCS n Suprascapularis
N. THORACICUS LONGUS
Position of limb: Patient prone, sitting or reclining. Arm abducted 90 degrees.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over m.serratus anterior in the midaxillary line over the sixth or
seventh rib.
Position of reference electrode: Over the sternum.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites: Supraclavicular region
N. THORACODORSALIS
Position of limb: Patient prone, sitting or reclining.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over m. latissimus dorsi in the posterior midaxilary line.
Position of reference electrode: Over the eight or nineth rib in the midaxillary line.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
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Stimulation sites: Supraclavicular region
N. DORSALIS SCAPULAE
Position of limb: Patient prone, sitting or reclining.
Type of recording electrodes: Needle or surface plate electrodes.
Position of recording electrode: Over m. rhomboideus medial to the scapula at the level of spina
scalulae.
Position of reference electrode: In the midline over the eight or nineth spinous process..
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites: Supraclavicular region
N. PHRENICUS
Position of patient: Patient supine, sitting or reclining.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: At the level of the xiphoid process in the midaxillary line.
Position of reference electrode: Over the anterior superior iliac spine.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation site: The phrenic nerve is best stimulated percutaneously above the sternum close to the
insertion of the sternocleidomastoideus muscle. If this is not possible it may be stimulated around the
posterior border of m.sternocleidomastoideus, at the upper level of the thyroid cartilage.
Picture of MCS n Phrenicus
N. ACCESSORIUS (to m.trapezius)
Position of patient: Patient supine, sitting or reclining. Head turned 45 degrees to the side
contralateral of the measurement.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over the upper part of m.trapezius, at the junction of the middle and
lateral third of the upper border of the muscle.
Position of reference electrode: Over the acromio-clavivular joint.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
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Stimulation sites:
At the base of the scull immediately in front of the insertion of m.sternocleidomastoideus.
Posterior triangle of the neck, behind m. sternocleidomastoideus.
Picture of MCS n Accessorius
N. ACCESSORIUS (to m.sternocleidomastoideus)
Position of patient: Patient supine, sitting or reclining. Head turned 45 degrees to the side
contralateral of the measurement.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over the midportion of m.sternocleidomastoideus.
Position of reference electrode: Over the sternum.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites: At the base of the scull immediately in front of the insertion of m.sternocleidomas-
toideus.
Note: This technique is useful in the evaluation of the effect of botulinus toxin in patients that are
suspected of beeing refractory to the toxin.
N. FACIALIS
Position of patient: Supine, sitting or reclining.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Depends on which branch of the facial nerve is studied.
R. temporalis: m.frontalis, 20 mm above the middle of the of the upper border of the orbit
Bischoff: R.zygomaticus: m.orbicularis oculi, below the the lateral third of the eye.
R. zygomaticus: m.nasalis, lateral to the midportion of the nose.
R. buccalis: m.orbicularis oris, on the lateral side of the lip.
R. buccalis: m.mentalis, 20 mm below the lower lip and 20 mm lateral to the midline.
R. mandibularis m.depressor anguli oris, below the lateral side of the lower lip 20 mm above the
margin of the mandible.
R. cervicalis: m.platysma, 3-5 cm in front of the mid-portion of m.sternocleidomastoideus
Position of reference electrode: On the contralateral side in the homologous area.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
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Stimulation sites: Immediately below and anterior to the pinna of the ear. The individual branches
may be stimulated more distally if necessary.
Anomalies: The branching of the facial nerve is highly variable.
Picture of MCS n Facialis
N. HYPOGLOSSUS
Position of patient: Supine, sitting or reclining.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Below the chin, overlying m.genioglossus.
Position of reference electrode: Over the same muscle on the contralateral side.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites: The medial to the posterior angle of the mandible.
N. PERONEUS PROFUNDUS
Position of limb: Patient supine, sitting or reclining.The ankle joint in a relaxed, neutral position.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: In the middle of m.extensor digitorum brevis.
Position of reference electrode: At the fifth metatarsophalangeal joint.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Ankle, 80 mm proximal to the recording electrode, lateral to the tendon of m.tibialis anterior.
Below knee, 20-50 mm distal to the proximal part of caput fibulae.
Above knee, 50-90 mm above caput fibulae, medial to the tendon of m.biceps femoris.
Anomalies: m.extensor digitorum brevis is innervated by n.peroneus profundus alone in most
subjects. In some subjects there may be an acessory branch from n.peroneus superficialis to
m.extensor digitorum brevis.
Note: The distance in the segment across the knee should be at least 100 mm.
Picture of MCS n Peroneus profundus
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N. PERONEUS SUPERFICIALIS
Position of patient and limb: Patient supine, sitting or reclining. Leg extended.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over the belly of m.peroneus longus. The point is over the lateral
side of the leg at the juction of the upper and middle third of the fibula.
Position of reference electrode: Lateral malleolus.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Below knee, 20-50 mm distal to the proximal part of caput fibulae.
Above knee, 50-90 mm above caput fibulae, medial to the tendon of m.biceps femoris
Note: The distance of the segment across the knee should be at least 100 m.
N. PUDENDUS
Position of patient and limb: Patient supine, preferably on a gynecological examination table.
Type of recording and stimulating electrodes: Special electrode that is mounted over a glowe on the
forefinger. At the tip there is pair of stimulating electrodes and at the base a pair of recording
electrodes (St Mark´s pudendal electrode; Comercially available from Medtronic, type 9013L0402 or
9013L0401)
Position of recording electrodes: Sphincter ani externus, additional electrodes may be placed in the
urethral sphincter.
Position of reference electrode: Sphincter ani externus.
Stimulation site: Laterally over the ischial tuberosity.
Note: Only DLAT and AMPL are measured.
N. TIBIALIS
Position of patient and limb: Patient prone or reclining. Legs extended.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: The site of the recording electrode depends on the distal branch that
is under study.
N.plantaris lateralis: over middle of the m.abductor digiti minimi, on the lateral side of the foot.
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N.plantaris medialis: over the middle of m.abductor hallucis, this is 10 mm below the posterior part of
the navicular bone.
Position of reference electrode:
N.plantaris lateralis: Over the proximal phalanx of digit V.
N.plantaris medialis: Over the proximal phalanx of digit 1.
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation sites:
Below medial malleolus (around 50 mm below the middle of the malleolus).
Above medial malleolus (around 50 mm above the middle of the malleolus).
Knee, in the fossa poplitea.
Picture of MCS n Tibialis
N. TIBIALIS, H-reflex
Position of patient and limb: Patient prone or reclining. Legs extended.
Type of recording electrodes: Surface plate electrodes.
Position of recording electrode: Over m.soleus halfway between the knee and ankle
Position of reference electrode: Over the Achilles tendon
Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation site: Knee, in the fossa poplitea.
Picture of H-reflex n Tibialis
N. FEMORALIS
Position of patient and limb: Patient supine, sitting or reclining. Hip and knee extended.
Type of recording electrodes: Surface electrodes.
Position of recording electrode:
over m.vastus medialis, on the anterior-medial aspect of the thigh at the junction of the middle and
lover third of the thigh.
over m.vastus lateralis, on the anterior-lateral aspect of the thigh at the junction of the middle and
lover third of the thigh.
over m.rectus femoris, on the anterior aspect, midpoint between the anterior superior iliac spine and
the upper edge of the patella.
Position of reference electrode: Below the medial epicondylus of the knee.
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Type of stimulating electrodes: Surface electrodes on a fixed bar.
Stimulation site: Surface or needle electrode below the inguinal ligament.
Note: Conduction velocity cannot be calculated, only the conduction time from the inguinal ligament
to muscle is measured. The amplitude and area of the response are also measured.
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MCS Median nerve
MCS n interosseus anterior
MCS n Ulnaris
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MCS n Radialis
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MCS n Musculocutaneus
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MCS n Axillaris
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MCS n Suprascapularis
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MCS n Phrenicus
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MCS n Accesorius
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MCS n Facialis
MCS n Peroneus profundus
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MCS n Tibialis
H-reflex, n Tibialis
