pain

It is unpleasant sensation that warns the body of tear or damage of the tissue.

Type of pain:

1-Acute pain; is feeled when tissue damage is impending and after injury has occured.

2-chronic pain ;It lasts for more than 6 months.

Another classification:

1-Referred pain;is pain that is preceived to be in the area that seems to have little relation to the pathology.

2-Radiating pain; pressure on the lumber nerve roots associated with herniated disc  can result in pain radiating down  the lower extremity to the foot.

3-Deep somatic pain ; is sclerotomic pain , there is often discrepancy between the site of the disorder and the site of the pain.

Scales for pain assessment:

 1-verbal rating scale ;it uses words to describe pain as no pain, mild pain , moderate pain , sever pain.its score from 0 to 3.

 2-Numerical rating scale ;    it is another type of pain scale that is used.  it is with the range of 0 to 10. The words “no pain” appear by the “0″ and “worst pain possible” is found by the “10.” and the patient marks a number from 0 to 10 which describe his pain level.

 3-visual analogue scale; it uses  a vertical or horizontal line with words that convey “no pain” at one end and “worst pain” at the opposite end. the patient mark the point which refers to his pain.

pathway of pain:

A nociceptive neuron is one that transmits pain signals its cell body is in the dorsal root ganglion near the spinal cord,approximately 25 percent of the myelinated A-delta and 50 percent of the unmyelinated C fibers contact nociceptors . once nociceptor is stimulated it release neuropeptide (substance P) that intiate electrical impulses along afferent fiber toward the spinal cord . substance P also serves as transmitter substance between first order afferent fiber and second order afferent fiber at the dorsal horn of the spinal column. the A-delta and C fibers which transmit pain and temperature have different diameters (A-delta are larger) and different conduction velocities (A-delta are faster) these difference result in two qualitatively different type of pain termed fast and slow. fast pain is brief,well localized,and well matched to the stimulus. slow pain is an aching,throbbing,or burning sensation that is poorly localized and less related to the stimulus . fast pain is transmitted over the larger faster conducting A-delta afferent neuron and originate from receptor in the skin  . slow pain is transmitted by C fiber that originate from skin ,ligament and muscle .some of A-delta and C fiber enter spinal cord through the dorsolateral tract of lissauer and synapse in the marginal zone(lamina 1) or substantia gelatinosa(lamina 2) with second order neuron . most of nociceptive second-order neuron ascend to the higher center along one of three tract (1)lateral spinothalamic tract (2) spinoreticular tract (3)spinoencephalic tract .with the remainder ascend along spinocervical tract or as projections to tha gracile and create nuclei of the medulla , approximately 90 percent  of second-order afferent terminate in the thalamus. third order neuron project to the sensory cortex and other centers in the central nervous system where the pain is perceived.

Theory for pain control:

Large diameter nerve fibers carry information from the site of injury to two destinations in the dorsal horn of the spinal cord: the “inhibitory” cells and the “transmission” cells. Signals from both thin and large diameter fibers excite the transmission cells, and when the output of the transmission cells exceeds a critical level, pain begins. The job of the inhibitory cells is to inhibit activation of the transmission cells. The transmission cells are the gate on pain, and inhibitory cells can shut the gate. When thin (pain) and large (touch, etc.) fibers, activated by a noxious event, excite a spinal cord transmission cell, they also act on its inhibitory cells. The thin fibers impede the inhibitory cells (tending to leave the gate open) while the large diameter fibers excite the inhibitory cells (tending to close the gate). So, the more large fiber activity relative to thin fiber activity coming from the inhibitory cell’s the less pain is felt.

pain management:

1-heat/Ice Packs ;they help to reduce muscle spasm and inflammation. it can be applied from 10 to 20 minutes once every two hours.

2-TENS;It uses electrical stimulation to modulate the sensation of pain by overriding the painful signals that are sent to the brain.it  may be used at home for low back pain relief on a long-term basis.

 3-Iontophoresis; This technique is used to deliver steroids through the skin using electrical current.this steroids have anti – inflammatory effect which relief  pain.

 4-ultra sound; This rays can penetrate soft tissue and has deep heating effect which promote healing.

5-Effect of exercise on pain relief; Exercising for just 30 minutes a day on at least increasing three or four days a week will help you with chronic pain management by :

a-Strength in the muscles.

     . b-Endurance

.  c-Stability in the joints

    d-Flexibility in the muscles and joints.