REGIONAL PAIN SYNDROME- TYPE 1
Regional Pain Syndromes type 1 and 2 represent regional pain disorders not
limited to the site of injury, with the following features:
Pain greater than might be expected from the original injury
2. Altered blood flow, localized edema, skin and hair changes
3. The pain itself may be burning or electrical in nature and is usually
non-dermatomal due to hyperalgesia. Allodynia is often present.
distinction between CRPS 1 and CRPS 2 is made by the specific neural mechanism
of injury. CRPS 1 patients have the involvement of the Sympathetic Nervous
System, while CRPS 2 patients have involvement of a specific injured Nerve.
Both syndromes exhibit pain beyond the distribution of the original injury.
1 patients were formerly diagnosed with Reflex Sympathetic Dystrophy. This
was a misnomer as the condition did not involve reflexes or dystrophy. The
current terminology was developed in 1994 by the International Association
for the Study of Pain (IASP). Typically CRPS 1 patients go for years without
a proper diagnosis. Although the classic case shows immobilization and guarding
of an extremity, with mottling of the skin, change in temperature, edema,
allodynia and dysesthesia, many cases present with variations of this theme
and can involve any or all of the extremities and even trunk or neck pain.
People with these conditions are aften misdiagnosed with psychogenic pain
disorders because of the non-dermatomal nature of their pain and the severe
psychological distress it engenders.
anatomical and physiological basis it appears that there are several processes
occurring. One involves central sympathetic coupling
with Wide Dynamic Range (WDR) Neurons in the Dorsal Horn serving to link the
Dorsal Horn Nuclei with Sympathetic Nuclei. Increased activity of Sympathetic
Efferents only tells part of the story. There is also an increase in Catecholamine
sensitivity at the site of the injury. Additionally the sustained pain from
the sensitization of Dorsal Root Ganglion Cells may trigger increased release
of epinephrine systemically and in the local area of injury.
treatment for CRPS 1 is mobilization to the affected extremity(ies). Pain
control with anticonvulsants (Gabapentin, Carbemazepine, Lamotrigine, Topramax),
Tricyclic Analgesics (Nortriptyline, Desipramine, Amitriptyline), Long Acting
Opioids (MS Contin, Oramorph, Kadian, OxyContin, Duragesic, Methadone), Alpha
1 Blockers (Phenoxybenzamine, Terazocin), Alpha 2 agonists (Clonidine), Sodium
Channel Blockers (LIdocaine, Mexilletine, Amantadine, Ketamine) and Calcium
Channel Blockers (Verapamil, Ditelizem, Niphedipine) may help individually
or in combination. Local Sympathetic Blocks of specific regional ganglia may
be very helpful, especially if the condition is caught in the acute phase.
These may be done without steriods and are often tried as a series of blocks
every day or every other day. At times a constant infusion with a catheter
may be necessary. Spinal Cord Stimulators can be highly effective. Intrathecal
pumps are useful in delivering opioids in combination with Sodium Channel
Blockers (Bupivacaine), Antispasmodics (Baclofen), or Alpha 2 agonists (Clonidine).