PainPain or pain conditons are
very common in medicine. They can be divided into acute and chronic
pain conditions. Acute pain Acute pain
is generated following surgery or when an acute traumatic injury happens. A soft
tisue injury or a laceration of the skin irritates nerve endings that are buried
in the tissue. The pain signals and neurotransmitters are different than in chronic
pain. Acute pain is short lived, mostly only a few days and with remobilization
and wound healing most of these conditions have resolved within 2 to 4 weeks (Ref.
1, p. 347). Chronic pain is one of the most common
symptoms that physicians are consulted about in their offices. Chronic
pain can have a multitude of causes. Typically it is caused from an underlying
chronic condition such as rheumatoid arthritis, degenerative arthritis or fibromyalgia.
One subtype of chronic pain is thought to be due to irritation of nerve fibers
or pain receptors ("nociceptive pain"). Another
chronic pain type is thought to originate from damage or dysfunction of a peripheral
nerve or from CNS pathology, such as a stroke or injury of the spinal cord ("neuropathic
pain"). The first type is felt as a pressure or as aching,
the second type as deep burning or excruciatingly stabbing. An example for nociceptive
pain would be cancer pain, for neuropathic pain would be pain from a stroke, diabetic
neuropathy in a chronic foot ulcer, or phantom pain after an amputation (Ref.
1, p. 753). Symptoms: When joints are involved in
pain, there is usually associated joint swelling, stiffness and a lack of range
of motion from the pain. Depending on what underlying structure is involved
(joint, bursa etc.) there is a difference in the clinical presentation and finding.
The patient needs to keep track of the pattern of pain and perhaps keep a pain
diary. It is a good idea to grade pain on a scale from 0 to 10 and communicate
this to the physician when the history of the pain is discussed. What makes the
pain better? What makes it worse? This will help the pain specialist to be able
to deduct what type of pain he is trying to control. Diagnostic
tests: It is likely that the physician has already done some X-rays
or other imaging studies such as MRI, CT scans or bone scans. Depending on the
clinical impression there may or may not be a need to do more tests such as blood
tests. A weakened grip can be measured using a Jamar dynanometer: 50 to 100 lbs.
would be a normal range. In a patient with wrist pain due to a complex regional
pain syndrome the best effort grip strength may only amount to 5 to 20 lbs. In
the table above a few common
pain conditions are listed with links to where they are described in more detail.
Under these links further diagnostic tests for these conditions can also be found.
Treatment: As the therapies in the various conditions
vary according to the findings and to the underlying pathology, treatments will
be reviewed in the chapters under these above links. However, generally speaking
modern treatment of pain conditions consists of early reactivation after surgery. Splinting
is avoided whenever possible. We have learnt a lot from the subspecialty of sports
medicine with regard to early diagnosis, aggressive rehabilitation, and if necessary
possibly early minor corrective surgery. If surgery is required, anatomical abnormalities
should be addressed with the minimum invasive procedure such as arthroscopic surgery
to avoid extensive tissue damage and excessive pain. This gets the injured athlete
through an injury a lot faster, with much less pain. Many other pain patients
benefit from a similar approach, from stretching of injured tissues and early
remobilization as soon after surgery as it is advisable. Often this is 2 or 3
days after the injury. Rest is avoided as much as possible. The links in the table
above lead to other chapters where more therapeutic modalities are mentioned.
"Downtoning" pain is a new trend that is catching on in recent
years. For prevention of pain syndromes surgeons will often premedicate the patient
just prior to surgery with one dose of 1200 mg of gabapentin
(brandname: Neurontin), which was shown in a double blind study to
reduce postoperative pain and pain pill use (Ref.2). This practice has been described
in lumbar spine surgery (discectomies), abdominal hysterectomies and mastectomies.
Gabapentin can also be used after surgery for a period of time to cut down pain
medication and help with early remobilisation. Gabapentin also is useful in an
adjunct to chronic pain management as is explained in the link above with regard
to treatment of diabetic neuropathy, which is a pain condition particularly difficult
to treat.
Restless leg syndrome Restless
leg syndrome is a neurological disorder. It is not a behavior problem as it was
thought of in the past by distraught parents and doctors. About 12 to 15 million
Americans are suffering from this syndrome, where they have abnormal or unpleasant
sensations under the skin and in the muscles of the lower legs, a burning, a feeling
like insects are crawling or sharp knife-like pain. It is relieved somewhat by
getting up and walking or running around, only to return very quickly when sitting
down. Patients with this condition have also often sleep disturbances, which can
be measured in the sleep laboratory. Diagnosis: Sleep
lab investigations are a good way to measure the severity of the restless leg
syndrome condition and to evaulate the impact it has on the patient's sleep hygiene.
It is known that sleep deprivation makes the symptoms worse and a reintroduction
of a regulated sleep/wake rhythm improves the symptoms. Treatment:
Recently there have been reports of a very beneficial effect of gabapentin, an
anti-epileptic drug. Gabapentin(brand name: Neurontin) releases GABA in some parts
of the brain and inhibits the NMDA pain receptors. This link describes the use
of it in the pain of complex
regional pain syndrome. Dr. Stephen Clarke, Clinical Assistant Professor
in the Div. of Neurology of the University of BC/Vancouver/Canada, reviewed the
use of gabapentin at a conference in Vancouver/BC in November 2004 (Ref. 3). Dr.
Clarke said that the use of gabapentin in restless leg syndrome is particularly
satisfying as the patients who tend to not respond to all of the other medications
respond in a high percentage of cases and this leads to a more normal life for
them. It is a very safe medication as outlined under the complex regional pain
syndrome link and the symptoms can be titrated by increasing the dose of the medication.
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