Origins of pain

Clinically important tip: What likes root pain?

Pure sensory Radiculopathy?

Neck and Back Pain

EDX important limitation Axonal loss: M&S&R loss Conduction Block:

◦ Non- demeylinating ◦ Demeylinating: M&S&R loss

Conduction slowing ◦ Differential: S&R loss, NCV can be normal:◦ Synchronized

◦ EDX= extension of neurologic examination

EDX

SNAP:◦ NL>>Amp>latency◦ C6,C7,C6&C7,C8,T1◦ L2-L3, L4,L5,S1

When SNAP dec?◦ Proximal DRG (severe L5)◦ Far lateral Herniation◦ Gangloionopathy (Dm/ herpes)

NCS

CMAP◦ NL>Amp>absent>latency: Why?◦ Abnormality in 6-8 days◦ C8/T1◦ L5/S1◦ S1/S2

NCS

H reflex:( GCS)◦ S radiculopathy 30-100% abnormality(definition)◦ Different pathway from ankle jerk reflex

H reflex:( FCR)◦ C6&C7 radiculopathy :17.4, 0.7 ms

Advantage: ◦ sensory radiculopathy

Disadvantage: ◦ Sensitivity&Specifity

Abnormal H(GCS)

NCS

F wave Fist finding in: GBS/Vasonervoum infarct F-wave abnormality: MMN Advantage:

◦ Immediately, Not readily accessible araes Disadvantage:

◦ Recurrent process◦ Motor only◦ If one root AbNl: others can mask it◦ Dilution◦ Non specific

NCS

Nerve Root Stim.◦ C5 SPC5&C6: BB◦ C6 SPC5-C8:TRC◦ C7 SPC8&T1:ADM◦ L5 SP TA◦ S1 SP GCS(lat)

Abnormal: amp/ latency Advantage:

◦ More sensitive than EMG Disadvantage:

◦ Doubt in stim location, only motor, dangers

NCS

Advantage:◦ Immediately, Sensory

Disadvantage:◦ Not sensitive to mild lesions◦ Variation◦ Dilution◦ No perfect localization◦ mixed: multi root assessment, ◦ segmental: really uni root, cervical?◦ Dermatomal?

SEP

Advantage:◦ Probably the highest Dx yield

Disadvantage◦ Motor only◦ Not immediately◦ Sometimes no conformation to H&PE

Myotomal charts vs. individual innervation Small number of fibers involved Cyclical presence of Fib/PSW

EMG

Fib/PSW◦ Advantage

Hall mark The most sensitive Before MUAP morphology change

◦ Timeframe: 1/3/-5,6 weeks. Is it questionable? Inc insertional activity

◦ Run of Fib/PSW 50 ms after stopping◦ First Abnormality after denervation◦ Don’t base your Dx.

EMG

CRD◦ Chronic phase, a few muscles: Paraspinal

Fasciculation◦ Chronic phase, a few muscles, not paraspinal◦ Sometimes the only finding◦ Rare but if myotomal then highly diagnostic

EMG

Hallmark of radiculopathy: paraspinal denervation (post. rami innervation)

Technique:◦ 1-2 cm ( L: 2.5) lateral&1 cm superior to SP◦ Angel: 45,60 then withdraw

Special technique in cervical; interspinal Instability?

◦ Difficult relaxation◦ Renervation

EMG

Other diseases : MND, Inflammatory myopathy, DM Trauma, Metastasis iatrogenic : myelogeraphy, LP, Rhizolysis,tomy Dorsal rami entrapment

EMG

Paraspinal findings after operation◦ Denervation ,anyway Can we say on “recurrence?

Techniques:◦ Lateral placement:

1 & 3 cm:+ in latter recurrence(?)◦ Semi-quantitive:

After 1 y: < 100, if> 300-600 recurrence Better in limbs as might be scar in paraS

Avoid it

EMG

Myotomal denervation in first 1-2 m: Axonal loss

The same but after >3 m: ongoing or progressive

◦ High Amp◦ Proximal muscles

Care on hematoma

EMG

EMG MUAP abnormalities

◦ Red.Recruitment Practically Difficult Reference data Not very useful in

mild lesions◦Variability

In acute phase◦ Incr.Duration

Incr.fiber asynchronicity

– Polyphasic• NL• Needs Quantitive EMG• Must be myotomal

_ Large, polyphasic and high duration MUAPs

SFEMG:◦ Jitter : inc◦ Block + acute◦ Block – chronic

Density

If new symptoms in 4-6 w denervation amp matters

EMG

Low sensitivity of EMG◦ Sensory only, Few fibers, slowly progressive,

Temporal◦ No FP if myotomal denervation

Imaging: low specificity _ 30-80% of normal individuals have

abnormal MRI

H&P/E: not “golden standard” So complimentary

Anatomic/Physiologic

How to name disks and SNs?◦ First (Second )disk :between C2 and C3 above◦ Fist Spinal Nerve between C0 and C1 below

Nerve root affection:◦ most: C7>C6◦ least :C8>C5

Cervical

C3/C4:◦ Nerves, tension headache

C5:◦ SS,IS,DeL,BB,SuP,BR if + PT,FCR,ECR then C6 or

multi, Paraspinal helpful◦ Rhomboid: Only (findings matter)◦ If PT + : R/O isolated C5

C6:◦ All above, cant separate from C5; H helps

Cervical

C7:◦ AnC, PT, FCR, EDC, plus: FCU& FPD◦ H ◦ IF TrC - R/O

C8/T1:◦ (FDP,ADM,PQ,APB,OPB) + Trc/EIP◦ Radial innervated muscles: T1 Less◦ TrC: C8 less not involved◦ APB: T1 more

Cervical

Singular > Multiple If not singular other side Bilateral? If multiple and bilateral:

◦ Other causes ◦ Neuropathy Lower limb

Cervical

DDx◦ MPS◦ MSK◦ Partial plexopathy

Upper trunk Middle trunk Lower trunk Paraspinal and SNAP can help

Double-crush injury◦ If C6/C7 then R/O CTS◦ IF C8/T1 then R/O cubital T.

Cervical

Uncommon , T8/T12 ( T11/T12) Cx:

◦ CM. CE / Myelopathy◦ Band like chest pain> Lower pain>wekness

ETX:◦ DM, Trauma, herpes, V collapse, metastasis, Pott,

dislocated rib. EDX:

◦ EMG: paraspinal( relaxation, DM)/ Abdominal muscles/Respiratory muscles

◦ CMAP(abdominal)◦ SEP(most reliable)

Thoracic

90% L5 and S1 due to mainly L4 and L5 discopathy

L4 herniation◦ Superiolateral: L4◦ Posterior: L5◦ Inferior: S1◦ Medial: multiroot bilateral

Other side Temporal issue

Lumbosacral

L2/3/4 : 12%◦ ParaS ,IlioP,AL,Gra, Quad◦ Few nerves, all proximal muscles

L5 :◦ ParaS/Hip girdle/Peroenal:EHL/FHL,FDL,GCS,TP

S1 : most common root◦ L5 :most common disk◦ ParaS/Hip girdle/TFL/Post calf,EDL.EHL/Foot intr.◦ H reflex◦ Cant separate from S2: maybe EDL onlyS1 but L5

S2/3/4◦ Anal sphincter/SoL/Foot inter. Always bilateral

Lumbosacral

L2/3/4◦ Diabetic amyotrophy◦ Femoral nerve injury◦ Obturator nerve injury◦ Lumbar plexopathy: SNAP, paraspinal

L5:◦ Foot drop

Peroenal palsy: SNAP of SPN, Block, EMG MND Plexopathy Peripheral polyneuropathy

DDX

L2/3/4◦ Diabetic amyotrophy◦ Femoral nerve injury◦ Obturator nerve injury◦ Lumbar plexopathy: SNAP, paraspinal

L5:◦ Foot drop

Peroenal palsy: SNAP of SPN, Block, EMG MND Plexopathy Peripheral polyneuropathy

DDX

S1/S2◦ Sciatic nerve injury◦ Sacral plexopathy

S2/3/4◦ Pudendal nerve injury

DDX