Peripheral Nerve InjuryPeripheral Nerve Injury

Neurosurgeon Neurosurgeon

Yoon Seung-HwanYoon Seung-Hwan

Anatomy Anatomy

• Connective tissue Connective tissue

- major tissue componant- major tissue componant

- epineurium, perineurium, endoneurium - epineurium, perineurium, endoneurium

• Nerve tissueNerve tissue

- axon, schwann cell - axon, schwann cell

Peripheral Nerve InjuryPeripheral Nerve Injury

• Acute injuryAcute injury

• Chronic injuryChronic injury

(entrapment neuropathy)(entrapment neuropathy)

ClassificationClassification

Neuropraxia

• the mildest form, reversible conduction

block

• loss of function, which persists for hours

or days

• direct mechanical compression, ischemia,

mild burn trauma or stretch

Axontmetic

• axon continuity is disrupted

• fascicular integrity is maintained• Wallerian degeneration occurs

Neurotmesis

• laceration from sharp or blunt forces

• the only important consideration is

the timing of repair

• acute repair or more bluntly lacerated

nerves are repaired 3-4 weeks

Factor s for Decision Making Factor s for Decision Making

• AgeAge

• Segment between injury and end organ Segment between injury and end organ

• Gap of injuryGap of injury

• Mechanism of injuryMechanism of injury

• Severity of injurySeverity of injury

• Presence of painPresence of pain

Axonal RegenerationAxonal Regeneration

• Initial delay Initial delay

to the distal stump : 1-2 week delayto the distal stump : 1-2 week delay

• Growth rateGrowth rate

1mm/day, 1 inch/month1mm/day, 1 inch/month

• Terminal delayTerminal delay

several weeks-several monthsseveral weeks-several months

Recovery within 6 weeksRecovery within 6 weeks good prognosis good prognosis

Fibrillation potentials andFibrillation potentials andpositive sharp wavespositive sharp waves

Acute DenervationAcute Denervation

Long duration, small amplitude Long duration, small amplitude polyphasic motor unit potentialspolyphasic motor unit potentials

Regeneration Regeneration

Clinical SignsClinical Signs

• Motor functionMotor function

• Tinel’s signTinel’s sign

positive-sensory functionpositive-sensory function

negative(after 4-6weeks)-total interruptionnegative(after 4-6weeks)-total interruption

• Sweating-sympathetic fiberSweating-sympathetic fiber

• Sensory functionSensory function

Diagnosis Diagnosis

Tinel’s sign

• advancing along the anatomical distribution of the nerve, particularly if it is does so at the expected rate of nerve regeneration, then this provides evidence of ongoing regeneration.

Electrophysiological TestsElectrophysiological Tests

• EMGEMG

• SNAPSNAP

• SSEPSSEP

• Intraoperative NAP Intraoperative NAP

Diagnosis Diagnosis

EMGEMG SNAPSNAP

SSEPSSEP

Intraoperative NAPIntraoperative NAP

Muscle AtrophyMuscle Atrophy

• 24 month rule 24 month rule

-- 22 년 이상 지속 시 년 이상 지속 시 muscle scar tissuemuscle scar tissue 로 대치되기 로 대치되기 때문 때문 에 에 (( 비가역변화비가역변화 ) ) 회복불가회복불가

• Muscle atrophyMuscle atrophy

start : post-injury 1 monthstart : post-injury 1 month

peak : 3peak : 3rd rd - 4- 4thth month month

• Segment between injury and end organSegment between injury and end organ

Time of OperationTime of Operation• Open injuryOpen injury

Early interventionEarly intervention

Delayed interventionDelayed intervention

• Closed injuryClosed injury

Delayed interventionDelayed intervention

TreatmentTreatment

Early InterventionEarly Intervention

• Enlarging hematoma/aneurysmal sacEnlarging hematoma/aneurysmal sac

• Predisposing to Volkmann’s ischemic Predisposing to Volkmann’s ischemic coco

ntracturentracture

• Severe noncausalsic pain SDSevere noncausalsic pain SD

• Injury to N. in areas of potential entrapmentInjury to N. in areas of potential entrapment

• Simple, clean lacerating injurySimple, clean lacerating injury

Delayed InterventionDelayed Intervention

• 2-3 months after injury2-3 months after injury

• No clinical or substantial recoveryNo clinical or substantial recovery

• 장점장점

1. 1. 손상범위를 정확히 알 수 있다손상범위를 정확히 알 수 있다 ..

2. 2. 동반손상의 치유로 감염을 줄인다동반손상의 치유로 감염을 줄인다 ..

3. Epineurium3. Epineurium 이 두꺼워져 봉합이 쉽다이 두꺼워져 봉합이 쉽다 ..

4. 4. 계획수술로 정확한 수술이 가능하다계획수술로 정확한 수술이 가능하다 . .

OperationsOperations• Neurolysis : Neurolysis : internal/externalinternal/external

• Nerve repairNerve repair

end-to-end repair : epineural/fascicularend-to-end repair : epineural/fascicular

autologous graft : sural N.autologous graft : sural N.

• NeurotizationNeurotization

intercostal N./accessory N./cervical plexuintercostal N./accessory N./cervical plexuss

within 1 yearwithin 1 year

• Muscle and tendon transferMuscle and tendon transfer

Epineural Repair Epineural Repair

Fascicular RepairFascicular Repair

Nerve GraftNerve Graft

# leading cause of failure of nerve graft # leading cause of failure of nerve graft

• Inadequate resection Inadequate resection

• Distraction of repair siteDistraction of repair site

Postoperative CarePostoperative Care

• Neurolysis : Neurolysis : 수술직후부터 운동시작수술직후부터 운동시작

• End-to-end repair :End-to-end repair : 33 주 이상 고정주 이상 고정

66 주까지 서서히 운동주까지 서서히 운동

• GraftGraft :: 좀 더 일찍 운동 허용좀 더 일찍 운동 허용

과도한 관절운동은 과도한 관절운동은

피한다피한다

Injured Peripheral NerveInjured Peripheral Nerve

Evaluation of Closed InjuryEvaluation of Closed Injury

ConclusionsConclusions1. 1. Immediate primary repair in sharp injuries with suspected trImmediate primary repair in sharp injuries with suspected tr

anssection of nerveanssection of nerve

Immediate repair is especially important for brachial plexus Immediate repair is especially important for brachial plexus and sciatic nerve transsections because delay leads not onland sciatic nerve transsections because delay leads not only to retraction but also to severe scaringy to retraction but also to severe scaring

Bluntly transsected nerve best repaired after a delay of seveBluntly transsected nerve best repaired after a delay of several weeks. ral weeks.

2.2. A focally injured nerve should be explored if no functional rA focally injured nerve should be explored if no functional return within 8-10 weeks eturn within 8-10 weeks

3. Decision - making as to whether neurolysis or resection & re3. Decision - making as to whether neurolysis or resection & repair in a lesion in gross continuity based on intraoperative epair in a lesion in gross continuity based on intraoperative electrophysiological evaluation lectrophysiological evaluation

4. Split repair with usually graft - lesion in continuity4. Split repair with usually graft - lesion in continuity 가 가 partiapartial function or undergoing partial regenerationl function or undergoing partial regeneration

5. Careful patient selection for operation 5. Careful patient selection for operation

- - 특히 특히 plexus involved plexus involved 시 시

6. Nerve anastomosis 6. Nerve anastomosis 의 의 failure failure 주원인은주원인은 ① ① inadequate resectin of scarred nerve endsinadequate resectin of scarred nerve ends

② ② nerve suture distration nerve suture distration

7. A good end result requiring rehabilitation from onset of trea7. A good end result requiring rehabilitation from onset of treatment. Prevention of disuse, relief of pain, predicting probatment. Prevention of disuse, relief of pain, predicting probable end results of operative procedures. ble end results of operative procedures.

ConclusionsConclusions

Chronic Injuries of Peripheral Chronic Injuries of Peripheral Nerves by EntrapmentNerves by Entrapment

• PainPain

• ParesthesiaParesthesia

• Loss of functionLoss of function

Pathophysiology of EntrapmentPathophysiology of Entrapment

• Direct compressionDirect compression

segmental demyelinationsegmental demyelination

wallerian degeneration(distal)wallerian degeneration(distal)

• IschemiaIschemia

swelling of nerveswelling of nerve

microcompartment SDmicrocompartment SD

Conservative TxConservative Tx• IndicationsIndications

not long historynot long history

mild-moderate, intermittentmild-moderate, intermittent

reversible causereversible cause

pregnancy, oral contraceptive, endocrine pregnancy, oral contraceptive, endocrine abnormaliabnormalities(DM…), type writerties(DM…), type writer

• MethodMethod

nonsteroidal anti-inflammatory drugsnonsteroidal anti-inflammatory drugs

splint splint

Treatment Treatment

Surgical IndicationsSurgical Indications

• Failed conservative txFailed conservative tx

• Typical clinical findingTypical clinical finding

with electrodiagnostic datawith electrodiagnostic data

• SevereSevere

sensory losssensory loss

muscle atrophymuscle atrophy

motor weaknessmotor weakness

Treatment Treatment

Entrapment of Thoracic OutletEntrapment of Thoracic Outlet

• 원 인원 인

-- Cervial rib or anomalous transverse process of C7 Cervial rib or anomalous transverse process of C7

-- Fibromuscular bands or scalene muscle abnomality Fibromuscular bands or scalene muscle abnomality

• 진 단진 단

- X-ray - X-ray

- NCV & EMG- NCV & EMG

- Angiography – vascular anomaly- Angiography – vascular anomaly

• TxTx : Supraclavicular approach : Supraclavicular approach

- Best op. management - Best op. management

scalene anterior and medius M.

Carpal Tunnel SyndromeCarpal Tunnel Syndrome

thenal atrophy

Entrapment of Radial NerveEntrapment of Radial Nerve

Entrapment of Ulnar NerveEntrapment of Ulnar Nerve- Cubital tunnel - Cubital tunnel - Guyon’s canal- Guyon’s canal

Motor Deficit of Ulnar NerveMotor Deficit of Ulnar Nerve

• Bediction postureBediction posture :: clawing of ring & clawing of ring &

small fingersmall finger

• Froment’s sign : Froment’s sign : weakness of adductor pollicis, there will be flexion weakness of adductor pollicis, there will be flexion

of the interphalangeal joint of the thumb because of substitution of the median innervof the interphalangeal joint of the thumb because of substitution of the median innerv

ated flexior pollicus longus for a weak adductor pollicis ated flexior pollicus longus for a weak adductor pollicis

Meralgia Paresthesia Meralgia Paresthesia

Lateral Lateral femoral cufemoral cu

taneous nerve injurtaneous nerve injur

y (L1-2)y (L1-2)

Tarsal Tunnel SyndromeTarsal Tunnel Syndrome