Spinal and Peripheral Nerve Pain
Treatment of the underlying condition supersedes the treatment of the discomfort. In those situations where the cause of the peripheral neuropathy cannot be determined, treatment of the painful site is primarily symptomatic.
Diabetic Peripheral Neuropathy
Diabetic peripheral neuropathy can be quite disabling. Adequate sugar control in patients with diabetes was found to delay onset and slow the progression of the peripheral neuropathy. The symptoms are usually gradually progressive and may begin with mild numbness, tingling, or a burning sensation in the feet. Pain may occur later in the course of the disease. Patients may describe hypersensitivity to touch of the feet and the ankles. In other individuals, there may be a loss of sensation in the feet, for that reason, diabetic patients are prone to injury of their feet and development of poorly healing ulcers, without their knowledge. It is very important for diabetic patients to examine their feet on a daily basis and maintain excellent follow up regarding any injuries or wounds on their feet.
Other treatments include the use of antidepressants, specifically, the tricyclic antidepressants (TCA’s), such as amytriptiline. These relieve pain by altering levels of serotonin in the body. The antineuralgic properties of TCA’s were shown to be independent from their antidepressant properties. TCA’s are associated with a number of adverse side effects such as sedation, orthostatic hypotension, dry mouth, urinary retention, constipation, and weight gain. These side effects are more pronounced in the elderly. TCA’s shold be used with caution in the elderly, patients with heart disease, narrow angle glaucoma, and prostatism. Another class of antidepressants, the selective serotonin reuptake inhibitors (SSRI’s), may also be used . In general, the SSRI’s have not been found to be as effective as the TCA’s for the treatment of neuroptahic pain, but are better tolerated. The side effects of the SSRI’s include sweating, stomach upset, somnolence, dizziness, decreased libido, and ejaculatory disturbances.
Anticonvulsants have been found to decrease the intensity of the burning and lancinating (lightening bolt) sensations experienced with neuropathic pain. The most widely used anticonvulsant used at this time is gabapentin. The mechanism of action responsible for the antineuralgic properties of gabapentin is unclear. Its effect is at least partially modulated through central mechanisms, most likely athe the level of the spinal cord. The most common side effects of gabapentin are drowsiness, somnolence, and generalized fatigue. These side effects are usually transient, lasting an average of 2-3 weeks. The median effective daily dose ranges between 900-1200mg, although some patients respond to daily doses as low as 100mg and others require 3600mg. This drug does not have a lot of drug-drug interactions, which could be an attractive property for patients of polytherapy.
There have been several reports of promising effects by mexilitene for the treatment of painful diabetic neuropathy. Patients treated with intravenous lidocaine may notice temporary pain relief of discomfort. If those patients are placed on oral mexilitene, they may continue to have relief of discomfort. Side effects of mexilitene appear to be few. Caution must be used in patients with intracardiac conduction disease and these patients should be monitored by follow up electrocardiograms. Because of equivocal efficacy and potential for side effects, this drug should be reserved for patients who fail first line treatments.
Tramadol (Ultram) is a centrally acting, non-narcotic pain reliever. Recent studies have shown that it may also be effective for treatment of painful peripheral neuropathy at doses of at least 200mg a day. The most common adverse side effects of tramadol are dizziness, vertigo, nausea, constipation, headache, and somnolence.
Topical ointments may also be helpful. An over the counter ointment, capsaicin cream, may produce pain relief of diabetic peripheral neuropathy. Capsaicin is a product extracted from hot chili peppers. Its mechanism of action is depletion of substance P, which is a chemical modulator of pain. Caution must be exercised during its application, with care to avoid eye and mucous membrane contact. Significant side effects include a burning sensation at the application site, particularly when a large amount of cream is applied. A thin film of cream is all that is necessary to provide pain relief and may decrease the risk of side effects. This cream (0.25% to 0.75%) needs to be applied 3 to 5 times daily to the areas of affected by pain. Other prescription ointments are available that consist of a combination of many of these different medications. They are well tolerated and are minimally absorbed by the blood, which decreases the risk of side effects.
It is generally agreed that peripheral neuropathic pain is not
responsive to narcotics. This
drug is rarely used for treatment of neuropathic pain and should be
reserved for patients that have failed all other therapies.
Alcoholic neuropathy is probably the second most common type of peripheral neuropathy. In mild cases there may be sensory symptoms only, with complaints of burning or painful feet or painful paresthesias (lightening bolt-type sensations). With more advanced cases, motor weakness is present. In this condition the legs are always more affected than the arms. An unsteady gait, termed cerebellar ataxia, may result from cerebellar degeneration. The neuropathy develops slowly with continued alcohol abuse, and if abstinence is achieved, recovery is generally slow.
disorder is thought to be due to a deficiency of thiamine and other
The deficiency state may be due to inadequate dietary intake and
decreased absorption of vitamins, as well
as greater need for thiamine..
Treatment for these individuals is abstinence from alcohol and
nutritional supplements containing thiamine and Vitamin B complex.
Uremic neuropathy is a complication of chronic renal failure that may be present in 20% to 50% of patients with uremia. The disease may become less frequent because of more effective treatment of chronic renal failure, including chronic hemodialysis and renal transplantation.
It presents clinically with a slowly progressive, predominately sensory neuropathy. Cramps and unpleasant dysesthesias and paresthesias often occur primarily at arrest: they appear to be relieved by moving around or walking. Muscle weakness may also be present.
neuropathy usually stabilizes or improves with dialysis.
After renal transplantation, a rapid initial improvement is often
seen within 1 to 6 months.
on published evidence, the TCA’s and gabapentin are first line therapy
for the treatment of painful peripheral neuropathies. For most drugs, it
is essential to start at a
low dose, and to gradually titrate to an effective dose.
Starting at too high a dose or titrating too quickly can lead to
early discontinuation of the drug because of side effects.
If drug therapy is not successful in adequately relieving pain, consideration should be given to implantable therapies such as the spinal cord stimulator or intrathecal pump. New medications are being developed to utilize in the implantable intrathecal pump, that have successfully relieved the pain of peripheral neuropathy. A trial is performed to determine if a patient is a candidate for either of these therapies. If the patient receives greater than 50% pain relief during the trial, permanent implantation is then considered.
with all pain disorders, stress can aggravate and increase pain
symptoms. Therefore, stress
management and behavioral modification
are very important to achieve successful and long-lasting pain relief.