There are, however, many cases in which the patient may not need ongoing care by a pain specialist and can be treated by following some simple guidelines. How do we recognize the differences? How do we start to evaluate and treat pain?

Here is an overview of some of the issues involved with pain management - how to define, assess, and diagnose pain... as well as some simple principles involved in treatment. These more basic modalities are appropriately utilized first - before sending the patient on to additional specialty care.

BASIC DEFINITION OF PAIN
Pain can be defined in basic terms as:

• an unpleasant sensory event
• and an unpleasant emotional or psychological experience
• associated with or indicating actual or potential damage to tissue

It is important to realize that this definition clearly states that pain is more than just a physiological event - it is an emotional and psychological one as well. In addition, the practitioner should recognize that tissue injury may have already occurred and may not be ongoing - but pain may still exist. Also note that the definition leaves room for a psychological cause or component to the pain.

NORMAL PAIN SIGNALS AND PATHWAY
Normally pain is caused by a stimulus that activates free nerve endings. (This stimulus is known as "noxious" and the nerve endings are termed "nociceptors".)

These signals are then transmitted from the nerve endings in the body to the spinal cord (via what are known as A-delta and C fibers) and then to the brain (via the spinothalamic tract and the spinohypothalamic tract).

In the brain, the signals reach parts of the brain called the thalamus and the cortex.

The brain, in turn, sends signals downwards to the spinal cord to modulate or control the way these pain signals are transmitted upwards (this is done in an area called the dorsal horn). In a way, the brain controls how and how much signal it ultimately receives.

This is only a simplistic explanation. For those of you that want more details, take a look at these offsite links to a picture of the pathway and this excellent article on the anatomy of pain.

NEUROPATHIC PAIN
In neuropathic pain, the pain signals do not follow this normal course. Instead, the signals originate at different areas of the pathway (instead of at the free nerve endings mentioned above) and cause the sensation of pain. Sometimes what begins as a "normal" pain pathway can become an abnormal one - and different types of medications are often utilized in an attempt to stop this abnormal transmission of pain.

Among the types of medications that have actions on the nerves and pathways involved in neuropathic pain are:

• Topical local anesthetics
• Other topical agents such as Capsaicin
• Opioid medications
• Anticonvulsant agents
• Antidepressants

... and these medications are often used in different combinations for treating these pain syndromes.

Often it is neuropathic pain that lasts a period of time where psychological and emotional factors begin to play an important role. Patients that have moved beyond simple pain to a neuropathic pain state may require more intense treatment by multiple specialists that includes psychological and emotional considerations.

ASSESSING PAIN
It is very important in the assessment of pain that attention is paid to the following issues:

• Location of pain: is it in a single place or multiple locations on the body? The location and pattern of distribution of the pain can lend clues as to the cause.
• Nature of pain: is the pain intermittent - that is, does it come and go depending on something that the patient does, a certain movement or body position, etc.? Or is it constant - as a result of continuous stimulation of pain receptors by something?
• Duration of pain: is the pain acute - that is, related to an injury (such as a cut from a knife) and associated with normal pain responses? Is the pain chronic - lasting for months due to an ongoing condition or not necessarily related to an obvious event?
• Intensity of the pain - often measured on a scale of one to ten. Consider not only the absolute intensity but also whether the pain seems appropriate for the stimulating event. An extreme response suggests that neuropathic and psychosocial issues may be involved.
• Quality of pain - is it sharp? Does it burn? Does it feel like an electrical shock? Does it follow a certain path in the body (like sciatica)?
• Other factors - is the patient reporting other symptoms such as depression, sleep disturbances, changes in appetite, etc?

BASIC PRINCIPLES OF TREATMENT
It may seem obvious but it is important that an attempt is made to identify the cause of the pain - often treating or removing the cause is an effective means of treating the pain. This is not always possible - a cause may not be apparent or the cause may be known but not treatable.

Treatment of the pain should be guided by the classification of the pain:

For pain that is nociceptive, meaning it follows the normal physiological pattern of noxious stimuli activating free nerve endings, "traditional" pain medications are utilized. These include the non-steroidal anti-inflammatory agents (like ibuprofen) and/or opioid medications. Examples of nociceptive pain include injuries (broken bones, etc.) and the pain following surgery.

More on treatment of nociceptive pain:

• Management of Chronic Non-Malignant Pain

For pain that is neuropathic in origin (suggested by features such as abnormal duration, electrical or burning sensation, etc.) the addition of agents such as those mentioned earlier is often helpful. Phantom Limb Pain, discussed previously on this site, is an example of a neuropathic pain syndrom.

More details on neuropathic pain:

• Hospital Practice article: Neuropathic Pain
• University of Iowa Pain Medicine Center article
• Pharmacologic Management of Neuropathic Pain
• Brain Briefings: Neuropathic Pain

Pain that involves psychological factors should be considered anytime a situation cannot be clearly explained by a known injury, disease, medical condition, etc. Patients may both a physiological and psychological mechanism to their pain and require both medication-based and psychological treatment. These patients are the ones that often require a multi-specialty, multiple practitioner treatment plan.

More information on psychological issues and pain:

• Pain: Psychological Paradigms and Practice - an article from Forensic Psychologist
• Psychological Pain Management from Psychology Information Online