Neural Mobilization Exam + Intervention

Question 1

Current State of evidence for efficacy of neural mobilization

Ellis et al.

Basson et al.

Answer 1

see pics

Question 2

Neural Structure

2 Main Types of Tissue:

Answer 2

1. Impulse gen. and conduction
   
   1. axons, myelin, Schwann cells
2. those assoc’d w/ support and protection of the impulse conducting tissues
   
   1. neuroglia, Schwann cells, connect. tissue layers

Question 3

Connective tissue relationships exist from _____ TO _____

Answer 3

from axon TO neuraxis

Question 4

Approx 50% of the P. nerve is connective tissue sheath

Some stats..

Answer 4

• Ulnar N. @ elbow= 21%
• Sciatic N. @ buttocks= 81%

Question 5

4 Major tissue layers in and around the P. nerve

Starting from the axon (innermost) and working to exterior of the nerve

Answer 5

• Endoneurium
• Perineurium
• Epineurium
• Mesoneurium

Question 6

Endoneurium

“Inner-most” layer

Answer 6

• Surrounds neuron
• HIGHLY elastic→ made of close packed collagen tissue
• Contains endoneurial fluid under positive pressure
• *responsible for maint. healthy environment of axon
  
  • Blood-Nerve Barrier***
• Contains NO LYMPHATICS
  
  • if swells– cannot drain

Question 7

Perineurium

Endoneurium→ Perineurium

Answer 7

• Surrounds Fascicles (bundles of endoneurium)
• Multi-layered→ most collagen fibers running parallel to nerve fiber
• HIGHLY resistant to tensile forces
• Acts as BOTH mechanical barrier to mech. forces and a diffusion barrier to keep substances OUT of intrafascicular environment
• Contains NO LYMPHATICS
  
  • if swells→ cannot be drained

Question 8

Epineurium

Endoneurium→ Perineurium→ Epineurium

Outer vs. Inner

Answer 8

• Outer Epineurium
  
  • contains vascular comps→ lymphatics AND blood supply
• Internal Epineurium
  
  • surrounds and protects fascicles from ext. trauma
  • allows for interfascicular gliding

Question 9

Mesoneurium

Endoneurium→ Perineurium→ Epineurium→ Mesoneurium

Answer 9

• Forms loose connect. tissue sheath around nerve
• Facilitates nerve gliding of AND anchors nerve in the nerve bed
• *W/ injury→ often becomes fibrotic and shrinks to constrict nerve and forms adhesions to the nerve bed

Question 10

Nerve Root Complex

Components of this:

Answer 10

1. Dorsal and Ventral Roots
2. Dorsal Root Ganglion (DRG)

Question 11

Nerve Root Complex

Dorsal and Ventral Roots

Answer 11

• RARELY damaged from traction force 2* to protective and force distributive mechs.
  
  • i.e. denticulate ligs
• receive @ least 50% nutrition from CSF

Question 12

Nerve Root Complex

Dorsal Root Ganglion (DRG)

Answer 12

• Normally minimally mechanosensitive
  
  • poke, prod== no response
• Once irritated→ very mechanosensitive
• MAY become edamatous
  
  • This cond. is hypothesized to improve via pumping action w/ mvmt

Question 13

Connective Tissue Relationships:

P. nerves to Neuraxis

What are they continuous with?

Answer 13

• Epineurium continuos w/ Dura Mater
• Perineurium MOSTLY cont. w/ dura, portion cont’s as Pia mater
• Endoneurium cont. w/ Pia mater

Question 14

The Meninges

3: Inner→ Outermost

Answer 14

1. Dura mater
2. Arachnoid mater (spider-web like)
3. Pia mater

Question 15

The Meninges:

Dura mater

Answer 15

• Strong longitudinally→ mostly collagen fibers in long. orientation
• Elastic as well*→ Elastin content varies 7% ventral to 14% dorsal

Question 16

The Meninges:

Arachnoid mater

Answer 16

• Delicate mesh (spider-web) of collagen fibers in random orientation
• Lines inside of dura

Question 17

The Meninges:

Pia mater

Answer 17

• Another collagen mesh-like structure
• Lines outer surface of brain & SC

Question 18

The Meninges:

Pia + Arachnoid mater TOGETHER→

Answer 18

Leptomeninges

• Embryologically ONCE one memb.
• Interconnections (trabeculae) b/w the two dampen CSF pressure waves from mvmt.

Question 19

The Meninges:

As a Muscle Attachment.. explain

Answer 19

• Evidence of MYO-dural (muscle→ dura) connections b/w suboccipital mm’s
  
  • Rectus capitis post. minor
  • Rectus capitis post. major
  • Obliquus capitis inf.

Question 20

The Meninges:

As a Muscle Attachment.. explain

Myodural Connections

Explain further: what does it DO?

Answer 20

• MAY assist in checking dural in-folding and impinge. during C/S Ext.
• Feedback function→ rich in proprioceptors
• Maint. proper dural tension to facilitate CSF dynamics
• MAY play a role in cervicogenic HA’s

Question 21

Potential for Nerve Injury:

Space + Contents Dilemma

Answer 21

• Nerve passes thru several tight anatomical comps along course of nerve bed
• Conflicts arise b/w avail. space and contents
  
  • diminished compartment aperture
  • INCd volume of contents
• RESULT:
  
  • restricted gliding b/w tissues in compartment
  • interrupted nerve physio.
  • impaired blood supply

Question 22

Circulation of the NS

Blood Supply to nerve

What is this called?

Answer 22

Vasa Nervorum

Question 23

Explain the Circulation of the NS

Vasa Nervorum

Answer 23

*Great redundancy!!!

• Neural tissue is O2 HUNGRY!!!
  
  • 2-6% of body mass but utilizes 20% of avail O2
• Redundant Design*
  
  • ensures uninterrupted blood flow to neurons regardless of mvmt or static pos. of NS
• Stretch and compression CAN alter circulation
  
  • hypoxia, edema, then fibrous changes in the nerve can follow chronic interruption in blood flow

Question 24

Axonal Transport Systems

Explain..

Answer 24

• Mvmt of mitochondria, lipids, synaptic vesicles, PROs, prions, organelles thru the cell’s axoplasm TO and FROM neurons Cell Body
  
  • Active→ HIGH energy demand process
  • Mvmt along microtubules acting as train tracks
  • Kinesin and dynein motor PROs move cargo along microtubules

Question 25

**Axonal Transport Systems:** Fast and Slow Transport

Answer 25

* **FAST** (50-400mm/day) * analogous to taking the **express train** * **SLOW** (.1-6mm/day) * analogous to taking the **local train** w/ **lots of steps along the way**

Question 26

**Axonal Transport Systems:** **Anterograde Transport**

Answer 26

**AWAY** from cell body (soma) * **FAST→** responsible to transport of **neurotransmitter vesicles** * 400mm/day * **SLOW→** resp. for transport of **cell building materials** * microtubules and neurofilaments→ .1-1mm/day * Actin→ 2-3mm/day * ~200 other PROs @ speeds up to 6mm/day

Question 27

**Axonal Transport Systems:** **Anterograde Transport** **AWAY from cell body** **Example:**

Answer 27

* During **reactivation from latency**, herpes simplex virus (HSV) hitches ride on the **anterograde transport** mechs to migrate from **DRG neurons** TO the **skin or mucosa** affected\*\*\*\*

Question 28

**Axonal Transport Systems:** **Retrograde Transport**

Answer 28

**TOWARDS** the cell body (soma) * **Returns** used synaptic vesicles TO SOMA (cell body) * **Informs** soma of cond's @ the axon terminals * Exploited by **pathogens** as well * **delay b/w infection and disease expression==\>** travel time TO SOMA * HSV * Rabies * Polio

Question 29

**Axonal Transport Systems:** **Kinesin Motor PROs**

Answer 29

* Utilizes **ATP→ ADP** as energy source\*\*\* * 125,000 steps= 1mm dist. traveled along microtubule-----WOW!!!

Question 30

**Axonal Transport Systems:** **Consequences of _disruption_ of axonal transport system**

Answer 30

* **Inflamm.** of the nerve * Loss of **nerve function** * Nerve becomes “**sick”**

Question 31

Neural Response to **Injury:** ## Footnote **_Mild_, _focal_ compression**

Answer 31

* Injury to **Schwann cell** * **Demyelination** results

Question 32

Neural Response to **Injury:** ## Footnote **More _severe_ trauma**

Answer 32

* **Degen.** of the **distal** axon * **Reactive changes** to **nerve cell body** * aka **Wallerian Degeneration** * NOTE: recovery NOT possible w/out **Sx**

Question 33

Neural Response to **Injury:** ## Footnote **Injury _w/out_ axonal degeneration**

Answer 33

* Inflamm **in and around** nerve sheath * Activates **C and A delta** fibers * **Nervi Nervorum** (nerve→nerve) involved: * innervates **connect. tissue** and **blood vessels** of the NS

Question 34

Neural Response to **Injury:** **EMG and NCV Testing** **\***NVC=Nerve Conduction Velocity

Answer 34

* \*\*ONLY valuable for detecting **larger diameter A-beta** **sensory & motor nerve injury** * “A-beta's make it betta” * **\*\*\*Of _no value_ for detecting _small diameter_ nerve injury** * C and A-delta fibers, Nervi Nervorum

Question 35

**How do we ID Pts w/ _Nerve Injury_ W/OUT _axonal degen?_**

Answer 35

* Nerve tissue becomes **mechanically sensitized** (C and A delta fibers via nervi nervorum) **in reaction to** _interruption of axonal transport_ and _inflammation_ in or around nerve * **Sensitized** neural tissue responded to *as little as 3% stretch*→ **well w/in normal mvmt parameters** * **_Sensitized neural tissue_ now reacts to _stretch_ and _pressure_** **\*NOTE:** These principles form the _physiologic basis_ for **Neurodynamic Testing!!!**

Question 36

Key Takeaways from Neurodynamic Testing:

Answer 36

* **Vast #** of nerve injuries **not detected** via **EMG/NCV** * **Neural sensitization** involves injury to **small diameter A-delta and C fibers** of the nerve AND **nervi nervorum** * Occurs thru **inflammation** and **interruption** of **axonal transport system** * \*Inflamm+Axon Neural Transport **very intimately related** * when you compress nerve→ becomes **pro-inflammatory** * In the Clinic.. * detected via **palpation** and **stretch** on clinical exam * aka how to detect **injured neural tissue**

Question 37

Neural Mobility Testing ## Footnote **Indications**

Answer 37

* Pain/parasthesia of neural origin deduced via exam and hx * Limtd mobility of NS * Injury of tissue **close to nerve beds** * whiplash * HS injury * Sciatic N. * Lat. Epicondylalgia * Radial Nerve * Medial Epicondylalgia * Ulnar N. * Ankle sprain * Sural and Superficial Peroneal N branches * Suspected cervical radiculo. * part of test item cluster to ID this patho * Post-op spine pts

Question 38

Neural Mobility Testing **Contraindications**

Answer 38

* **Acute** **inflammatory** **_infection_** involving SC or NS * Acute/recent onset of **hard neuro. signs** * loss of reflexes * localized mm weakness

Question 39

Neural Mobility Testing ## Footnote **Precautions**

Answer 39

* Malignancy * Be aware of stress to anatomical structures during testing * **Slump:** HNP concerns, nerve root impinge signs * Irritability lvl of the pts NS * Presence of stable hard neuro signs * Gen health issues: * IDDM/NIDDM, RA, MS, etc.. * Circulatory disorders

Question 40

Structural Differentiation w/ Neural Mobility Key Concepts

Answer 40

* always **skip an articulation (jt complex)** from where sx's are produced or changed during baseline tests * Add/Subtract tension to look for corresponding change in sx's * Symptoms typ **worsen w/ tension add→** but not always

Question 41

Meralgia Parasthetica assoc'd w/

Answer 41

LFCN entrapment

Question 42

Meralgia Parasthetica

Answer 42

Irritation or entrapment of **LFCN** @ **anterolateral hip** **@ risk=** baseball catchers, equestrians (Eng-style), obese indvs, pregnant women, ant. approach THA and hip arthroscopy pts)

Question 43

Test for Meralgia Parasthetica

Answer 43

push **w/ thumb down** into **abdomen** and **up toward umbilicus** @ lvl just proximal to and 1" medial to **ASIS**. If this **relieves pts sx's** of **lat. thigh burning, pain, or parasthesia→** suggests **meralgia parasthetica is problem** **To treat→** apply same pressure to the nerve w/ pt in **S/L,** while you simultaneously **passively extend hip** **\*push down and up on nerve as you ext hip,** then move back and forth