September 5th – 8th 2013Nottingham Conference Centre, United Kingdom

www.nspine.co.uk

Post-operative Lumbar Decompression:

Pathoneurodynamics

Ellen HobbsPhysiotherapist

September 2013

IntroductionLow Back Related Leg

Pain

Influence of neurodynamics

Pain and Pathoneurodynamics

Clinical Manifestation and Patient

Presentation

Case Study

Summary

Low Back Related Leg Pain• Leg pain frequently accompanies low back pain. (Schafer et al 2009)

• Decompression / Discectomy performed for leg pain.

• Present in approximately 25-57% of all low back pain cases (Heliovarra et al 1987; Cavanaugh and Weinstein 1994; Selim et al; cited in Schafer et al 2009)

• Accompanying leg pain is an important predictor for LBP chronicity (Selim et al cited in Schafer et al 2009)

• Primary pathology causing referred leg pain can be indistinct. Many structures can evoke similar patterns of pain (Adams et al 2002; Bogduk and McGuirk 2002 cited in Schafer et al 2009)

• Patients may be left with residual post operative leg pain; Necessary to understand the possible causes to optimise treatment.

Neurodynamics“The science of the relationships between mechanics and physiology of the nervous system.” (Butler 2005)

• Mechanical and physiological events of the nervous system are dynamically interdependent (Shacklock 1995)

• Mechanical stresses applied to nerves evoke physiological responses e.g. alterations in intraneural blood flow; impulse traffic and axonal transport (Shacklock 1995)

PhysiologicalImpulse generation and conduction.

Mechanicalmovement of the nervous system to slide, move and elongate in relation

to surrounding tissue.

Pathoneurodynamics

• Changes in neural dynamics or physiology may lead to pathoneurodynamics.

(Shacklock 1995)

• High likelihood in postoperative decompression patient

Neurodynamics

Mechanics Physiology

Pathomechanics Pathophysiology

Pathoneurodynamics(Shacklock 1995)

Peripheral Neuropathic Pain• Situations where nerve roots or peripheral nerve trunks have

been injured by mechanical or chemical stimuli that exceed the capabilities of the nervous system.

– Neural connective tissue nociceptor sensitisation– Abnormal impulse generating site (AIGS) formation– Impules conduction impairment

(Nee and Butler 2006; Ellis et al 2012)

• Neurodynamic tests assess the mechanosensitivity of the nervous system through sequential limb movements. (Boyd et al 2010)

Peripheral Neuropathic PainAIGS formation / Impulse conduction impairment

(Nee and Butler 2006)

Clinical Manifestation

Positive (Abnormal levels of excitability)

• Pain• Paraesthesia• Dysesthesia• Spasm

Negative (Reduced impulse conduction in neural tissue)

• Hypoesthesia• Anaesthesia• Weakness

(Nee and Butler 2006)

Objective Findings• Neural unloading antalgic posture

• Reduced active / passive movement

• Provocative neurodynamic testing (correlating the reduced active / passive ROM)

• Lines / clumps of pain over neural interface

• Nocturnal pain (due to reduced O2 perfusion)(Nee and Butler 2006; Welch 2011)

Treatment Techniques

What can we do for residual post operative leg pain?

• Mechanical Interface

• Nervous System

• Both(Welch 2011)

Case Study ExampleSubjective Assessment•68 year old lady•Left posterior LL pain to calf (burning / restless) (mild improvement) (p1)•Localised central LBP sharp/catching (p2)•23.05.2013 bilateral S1 lateral recess decompression. Revision L5 root decompression. Degenerative scoliosis•2x previous decompressions

– Right L3/L4 2002– Bilateral L5 (L4/5 L5/S1) 2010– Improved

•Subtotal colectomy / permanent ileostomy 2002•Angina•Gabapentin / Tramadol / Aspirin / Paracetamol / Olmetec / Atorvastatin

Objective Assessment• Lx scoliosis concave to left• Limited painful (p2) extension / side

flexion.• Reduced left hip active / passive ROM

IR 20 (p1 to mid thigh)• Normal power / sensation• Positive (p2) left SLR 30 / Slump -60

extension• + TrP HS / piriformis / mid calf• UMN NAD

Treatment• Arthrogenic (closing dysfunction)

– Rotational PPIVMS right SL GII. 30 sec x 3– Lx SF right SL– Work into neurodynamic range

• Mechanical interface– Inhibitory taping to differentiate / ? sciatic bifurcation ? piriformis– TrP acupuncture piriformis

• HEP– Slump slider (started with right) one ended / function– Cat / posterior pelvic tilt 4 point– Piriformis stretch

• Possible progressions / relate to function• Consideration of SIN factor / objective markers

Summary• Leg pain frequently accompanies low back pain. Post-operative decompression

patients may have residual leg pain.

• For effective treatment we need to consider neurodynamics / pathoneurodynamics.

• To optimise treatment we need to understand the neurobiological process involved that may contribute to pathoneurodynamics.

• Neurodynamic testing and differentiation can indicate potential structures / contributors involved in pathoneurodynamics.

• Treatment techniques aim to offload / open / close / facilitate gliding / reduce neural sensitivity.

Appendix

Physiological• Peripheral nerve structure and

movement• Blood supply to the nerve

–Epineurium• Outer vascular layer• Inner layer facilitates gliding• Allows bending

–Perineurium• Connective tissue• Diffusion barrier controlling fluids

–Endoneurium• Provides optimal nerve nerve fibre

environment(Welch 2011)

Mechanical• The Musculoskeletal system is the mechanical interface to the nervous

system i.e. anything lying next to the nervous system:

• Central and Peripheral components:

Peripheral

Muscles

Tendons

BoneDiscs

Ligaments

Fascia

Blood Vessels Central

Cranium

Neuraxia

Cranial Nerves

Meninges

Nerve Roots

(Nee and Butler 2011)

Injury / Degenerative CycleInjury Degeneration

MALAISEInflammation

ActivityPain

Biochemical Mechanical Imbalance stresses to injury

CHEMORECEPTORS MECHANORECEPTORS Spasm

Blood Flow Muscle action (protective guarding)

Protective Early onset fatigueguarding

Fluid congestion (Reid 2011)

NEURAL HYPER-

SENSITIVITY

Where is the pain evoked?

Peripherally evoked Centrally evokedStimulus / response fairly constant on testing

May not get positive / clear signs on testing

Neuroanatomical pattern May have summation, latency of high sin

Symptom linkage Allodynia / hyperalgesiaOften related to severe or prolonged injury

• Also consider autonomic effect: Sweating swelling skin changes.

Look for symptom reproduction / resistance to movement.Must use neural sensitizers to differentiate other structures

(Nee and Butler 2006; Welch 2011)

Lower Limb Nerve Anatomy Sciatic Nerve Femoral Nerve

LL Neurodynamic Testing

SLR• Supine (note pillows)• Passive straight leg raise (knee extended)• Add PNF, DF or hip internal rotation / adduction• Normal response: Posterior thigh, posterior knee and calf• Indications: All spinal and leg symptoms• Variations

– DF and inversion (sural)– DF and eversion (tibial)– PF and inversion

Consider sequencing: Greater strain at the site moved first ? Response localised to this site.Direction of neural sliding influenced by order that body movements are added.

LL Neurodynamic TestingSlump• Sitting with thighs supported and hands behind back• Flexion of spine• Cervical flexion• Active DF on asymptomatic side• Active DF on symptomatic side• Active knee extension on symptomatic side• Release of cervical flexion if symptoms reduced• NORMAL: Pain / pull mid Tx; Pain pull hamstrings / calf on DF and knee

extension; symptom decrease on release neck flexion / ankle PF.• Indications: Spinal symptoms, upper and lower limb symptoms

LL Neurodynamic TestingFemoral Slump• Side lying head on pillow slumped. Lowermost knee hugged to

chest. Therapist stands behind• Uppermost knee flexion and hip extension.• Extend head and monitor response• NORMAL: Anterior thigh tension• Indications: Spinal and anterior leg symptoms

• A positive test only indicates mechanosensitivity to elongation / compression or lateral sliding.

• It does not tell us the exact nervous system dysfunction.• Intraneural: Hypersensitivity of the nerve, AIGS development• Extraneural: Mechanical interface friction

Mechanical Interface Treatment• Opening dysfunctions: tension / elongation: Close to start then progress into the opening

dysfunction and into neural provocation positions• Closing dysfunctions: compression: Open to start then progress into closing positions

and into neural provocation positions• Can be:

– Arthrogenic• Example: Lx rotation PPIVMS = rotate away from side of pain opening IV foramen• AP glide fibular head

– Myogenic• Trigger point / acupuncture• Taping to offload: Inhibitory across muscle fibres. Neural offloading: reduces nociceptor

impulses• Example

• Neural Massage– Intrinsic blood supply to nerve has multidirectional flow– Massaging up and down along the line of the nerve can reduce venous stasis and improve neural circulation(Welch 2011)

Nervous System• Aim to perform joint movements that elongate the nerve bed.• This increase nerve elongation / nerve tension and intraneural

pressure.• Sustained intraneural fluid pressure reduces blood flow =

ischemic changes. (Myers et al 1986 cited in Coppieters and Butler 2007)

• HOWEVER: Correct application of a dynamic version in intraneural pressure may facilitate evacuation of intradural oedema and reduce symptoms. (Burke et al 2003 cited in Coppieters and Butler 2007).

• GLIDING: Tensioning or Sliding technique??

Sliding and TensioningSliding Tensioning

Alternating combined movements of at least two joints. • One movement lengthens the nerve bed. • The other movement simultaneously

reduces the nerve bed length unloading the nerve

Movement of one or several joints causing nerve bed elongation in relation to surrounding tissue.

Aim to mobilise the nerve with a minimal tension increaseResult in larger longitudinal excursion than tensioningOne ended: with the body: most neural movement occurs mid joint range

One ended: tension occurs in outer range

Two ended: applying tension in one end and letting go at another.

Two ended: Elongation from both ends

Useful for pain Useful for the nerve to adapt to elongation

(Coppieters and Butler 2007; Welch 2011; Ellis et al 2012)

Physiological EffectsSliders TensionersReduces sensitivity and restores function, thus easing the threat value of the injury.

THIS IS LIKELY TO; minimise the potential for ion channel up regulation in dorsal root ganglia and the CNS and limit the potential for dorsal horn and brain changes

Reduce intraneural swelling and circulatory compromise via fluctuating effects on intraneural pressure. Dynamic alteration of intraneural pressure results in ‘pumping’ or ‘milking’ action.Thought to enhance hydration and dispersal of local inflammatory products.

Involve large amplitudes, can be performed actively and passively and can be integrated into metamorphical movements thus distracting the patient from the condition.

Limit fibroblastic activity and minimise scar / adhesion formation.

Large range neutrally non-aggressive movements allows movement to be presented in novel ways the brain. This reduces fear avoidance and assists remapping. (Coppieters and Butler 2007)

ReferencesBoyd BS, Wanek L, Gray AT, Topp KS. Mechanosensitivity during lower extremity neurodynamic testing is diminished in individuals with Type 2 Diabeted Mellitus and peripheral neuropathy: a cross sectional study. BMC Neurology 2010, 10:75

Coppieters MW, Butler DS. Do ‘sliders’ slide and ‘tensioners’ tension. An alalysis of neurodynamic techniques and considerations regarding their application. Manual Therapy 2007, doi10.1016 pp 1-9.

Coppieters MW, Stappaerts KH, Wouters, LL, Janssens K. The Immediate Effects of a Cervical Lateral Glide Technique in Patients With Neurogenic Cervicobrachial Pain. Journal of Orthopaedic & Sports Physical Therapy 2003, Vol 33: No 7 pp 369 – 378.

ReferencesEllis RF, Hing WA, McNair PJ. Comparrison of Longitudinal Nerve Movement With Different Mobilization Exercises: An In Vivo Study Utilizing Ultrasound Imaging. Journal of Orthopaedic & Sports Physical Therapy 2012; Vol 42: No 8: pp 667-675

Hagert CG, Larsen AI, Jepsen JR, Kreiner S, Laursen LH. Editorial: Improving application of neurodynamic (neural tension) testing and treatments: A message to researchers and clinicians. Manual Therapy 2005, 10, pp175-179.

Herrington L, Bendix K, Cornwell C, Fielden N, Hankey K. What is the normal response to structural differentiation within the slump and straight leg raise test? Manual Therapy 13 2008 pp289 – 294.

Nee RJ and Butler D: Management of peripheral neuropathic pain: Integrating neurobiology, neurodynamics, and clinical evidence. Physical Therapy in Sport 2006, 7 pp 36 – 49.

ReferencesReid. An Introduction to PathoNeurodynamics Handbook. 2011

Saranga J Green A, Lewis J, Worsfold C. Effect of a Cervical Lateral Glide on the Upper Limb Neurodynamic Test 1: A blinded placebo-controlled investigation. Physiotherapy, 89, 11 pp678 – 684.

Shafer A, Hall T, Briffa K. Classification of low-back related leg pain-A proposed patho-mechanism based approach. Manual Therapy 14, 2009: pp 222 – 230.

Shacklock M: Neurodynamics. Physiotherapy; January 1995, vol 1, no 1.

Welch H. Neurodynamics Masterclass handbook. 2011