PAIN AND ITS MANAGEMENT D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY

SOMATOSENSORY CORTEX SOMATOTOPIC ORGANIZATION MORE AREA TAKEN BY SENSITIVE REGIONS (GREATER RECEPTOR DENSITY-SMALLER RECEPTIVE FIELDS) CELLS RESPONDING TO ONE TYPE OF SENSATION IN VERTICLE COLUMNS(FOR EXAMPLE..PACINIAN CORPUSCLES IN A FINGERTIP)

THE ANTEROLATERAL PAIN AND TEMPERATURE PATHWAY SENSORY NEURONS SYNAPSE IN SUBSTANTIA GELATINOSA SECONDARY NEURONS CROSS MIDLINE AND ASCEND IN ATEROLATERAL COLUMN BRANCHES GO TO THE RETICULAR FORMATION TERMINATE IN VENTROBASAL NUCLEUS OF THALMUS TERTIARY NEURONS GO TO SENSORY CORTEX

THE ANTEROLATERAL PATHWAY SUBSTANTIA GELITANOSA

THE SENSATION OF PAIN FAST PAIN SLOW PAIN MECHANICAL PAIN CHEMICAL PAIN THERMAL PAIN

PAIN NERVES:

FAST PAIN OCCURS IN ABOUT 0.1 SECONDS SUBJECTIVE DESCRIPTION:SHARP, ACUTE, ELECTRIC OR PRICKING A FIBERS SYNAPSE ON CELLS IN LAMINA I (LAMINA MARGINALIS) IN THE DORSAL HORNS SECONDARY NEURONS CROSS AND TRAVEL THROUGH THE ANTEROLATERAL PATHWAY TO THE VENTROBASAL COMPLEX OF THE THALAMUS TERTIARY NEURONS GO TO THE PRIMARY SENSORY CORTEX

FAST PAIN PATHWAY VENTROBASAL NUCLEUS LAMINA MARGINALIS I II IV III VI SUBSTANTIA GELITANOSA ANTEROLATERAL PATHWAY IX VIII

SLOW PAIN OCCURS AFTER A SECOND OR MORE OFTEN ASSOCIATED WITH TISSUE DESTRUCTION SUBJECTIVELY DESCRIBED AS BURNING, ACHING,THROBBING, NAUSEOUS, OR CHRONIC C FIBERS WHICH SYNAPSE IN THE SUBSTANTIA GELITANOSA FINAL PROJECTION IS THE FRONTAL CORTEX

SLOW PAIN PATHWAY VENTROBASAL NUCLEUS LAMINA MARGINALIS I II IV III VI SUBSTANTIA GELITANOSA ANTEROLATERAL PATHWAY IX VIII

MECHANICAL, CHEMICAL AND THERMAL PAIN FAST PAIN IS GENERALLY MECHANICAL OR THERMAL SLOW PAIN CAN BE ALL THREE CHEMICAL PAIN RECEPTORS: BRADYKININ, SEROTONIN, HISTAMINE, POTASSIUM IONS, ACIDS, ACETYL CHOLINE AND PROTEOLYTIC ENZYMES PROSTAGLANDINS ENHANCE PAIN SENSATION

BRAIN STRUCTURES AND PAIN COMPLETE REMOVAL OF THE SENSORY CORTEX DOES NOT DESTROY THE ABILITY TO PERCIEVE PAIN STIMULATION OF THE SENSORY CORTEX EVOKES A SENSATION OF PAIN

PAIN CONTROL (ANALGESIA) THE ANALGESIA SYSTEM THE BRAIN’S OPIATE SYSTEM INHIBITION OF PAIN BY TACTILE STIMULATION TREATMENT OF PAIN BY ELECTRICAL STIMULATION REFERED PAIN

THE ANALGESIA SYSTEM PREAQUEDUCTAL GRAY RAPHE MAGNUS NUCLEUS PAIN INHIBITORY COMPLEX IN DORSAL HORNS

PAIN INHIBITORY COMPLEX: PRESYNAPTIC INHIBITION BRAIN STEM.NEURON ANTEROLATERAL PATHWAY INHIBITORY NEURON - PAIN RECEPTOR + DORSAL HORN OF SPINAL CORD

PAIN TRANSMISSION AND INHIBITION SUBSTANCE P IS THE NEUROTRANSMITTER: BUILDS UP SLOWLY IN THE JUNCTION AND IS SLOWLY DESTROYED PRESYNAPTIC INHIBITION BY INHIBITORY NEURON BLOCKS THE RELEASE OF SUBSTANCE P (ENKEPHALIN)

THE BRAIN’S OPIATE SYSTEM OPIATE RECEPTORS EXIST IN MANY CENTERS OF THE BRAIN, ESPECIALLY IN THE ANALGESIA SYSTEM AMONG THE NATURAL SUBSTANCES WHICH ACTIVATE THESE RECEPTORS ARE: ENDORPHINS, ENKEPHALINS, AND MORPHINE

INHIBITION OF PAIN BY TACTILE STIMULATION STIMULATION OF LARGE SENSORY FIBERS FOR TACTILE SENSATION INHIBITS PAIN TRANSMISSION FOR SAME REGION RUBBING OFTEN EASES PAIN LINAMENTS, OIL OF CLOVE, ETC. POSSIBLE EXPLANATION FOR ACUPUNCTURE?

TREATMENT OF PAIN BY ELECTRICAL STIMULATION STIMULATION OF LARGE SENSORY NERVES ELECTRODES IN SKIN OR SPINAL IMPLANTS INTRALAMINAR NUCLEUS OF THALAMUS

REFERED PAIN VISCERAL PAIN FIBERS SYNAPSE ON SAME SECONDARY NEURONS AS RECEIVE PAIN FIBERS FROM SKIN

CLINICAL ASPECTS OF PAIN HYPERALGESIA THE THALAMIC SYNDROME HERPES ZOSTER (SHINGLES) TIC DOULOUREUX THE BROWN-SEQUARD SYNDROME HEADACHE

HYPERALGESIA ENHANCED SENSITIVITY AROUND DAMAGED TISSUE SENSITIZATION OF NOCICEPTORS BY SUBSTANCES RELEASED WHEN TISSUE IS DAMAGED

THE THALAMIC SYNDROME LESION OF SOMATOSENSORY THALMUS USUALLY A DISTORTED AND EXAGERATED SUBJECTIVE QUALITY MAY CUT OFF PAIN TRASMISSION FROM PERIPHERY

HERPES ZOSTER (SHINGLES) USUALLY AFFECTS THE DORSAL ROOT ONE DERMATOME AND ONE SIDE

TIC DOULOUREUX CHRONIC NEURALGIA OF TRIGEMINAL NERVE SOMETIMES DUE TO INFLAMMATION (NEURITIS) SOMETIMES TREATED SURGICALLY, BUT OFTEN RETURNS

THE BROWN-SEQUARD SYNDROME CHARACTERISTIC PATTERN OF SENSORY LOSS DUE TO LOCALIZED DAMAGE ON ONE SIDE OF SPINE USUALLY ACCOMPANIED BY MOTOR LOSS AS WELL

LESION ON RIGHT HALF OF SPINAL CORD LOSS OF PAIN SENSATION ON LEFT SIDE BELOW LESION LOSS OF TOUCH AND VIBRATION ON RIGHT SIDE BELOW LESION LOSS OF BOTH ON RIGHT SIDE AT SAME LEVEL NO LOSS ABOVE LESION

HEADACHE SELDOM DUE TO BRAIN DAMAGE NO SENSORY NERVES IN BRAIN LIKE THERE ARE IN PERIPHERY TENSION INDUCED MUSCLE TIGHTNESS SWELLING OF THE MUCOUS MEMBRANES EYE DISORDERS DILATION OF CEREBRAL BLOOD VESSELS INCREASED INTERCRANIAL PRESSURE INFLAMMATION AND SWELLING