Pain Control Theories

Pain Anatomy Review

Primary Afferent Fibers 1st Order Neurons

Pain Anatomy Review

Primary Afferent Fibers 1st Order Neurons Dorsal Horn

Pain Anatomy Review

Primary Afferent Fibers 1st Order Neurons Dorsal Horn Spinothalamic Tract

Gait Control Theory

Pain can be altered by blocking impulses within pathwaysStimulate A-beta stimulates substantia gelatinosa A-beta’s are faster than

A-delta and C fibers

How does this work? Gate Open Gate Closed

Endogenous Pain Control

Ascending Influence on Pain Control Similar to Gate

Control A-beta triggers

release of Enkephalin

Inhibits Substance P at junction between 1st and 2nd order neurons

Endogenous Pain ControlDescending Influence on Pain Control (Central Biasing) Stipulates that higher

brain centers can modulate pain

PAG and RN Dorsal Lateral Tracts Enkephalin Interneurons

Release of serotonin Past experience,

emotional influences and sensory perception

Endogenous Pain ControlBeta-Endorphin Mediated Model What is Endorphin? Found in

hypothalamus and periaqueductal gey matter

Activation of small diameter fibers

Release of BEP

Acute vs Chronic Pain

Acute PainDefinition

Pain of recent or sudden onsetFunctionPrimary HyperalgesiaSecondary HyperalgesiaPain-Spasm-Pain Cycle

Acute vs Chronic Pain

Chronic Pain Definition

Pain of long duration, often associated with anguish, apprehension, depression, hopelessness

Consider neurophysiologic and psychologic factors

Four Levels of Chronic Pain Nociception Pain Suffering Pain Behaviors

Other Types of Pain

MFPSChronic PainNo single causeS/S

Pain Management

Must consider physiological, behavioral and cognitivePhysical Modalities

Behavioral Reducing anxiety Explain treatments

Cognitive Central Biasing

Relaxation techniques, motivation etc