Diabetic Truncal Neuropathy

THE CLINICAL SYNDROME

Diabetic neuropathy is the name used by clinicians to describe a heterogeneous group of diseases that affect the autonomic and peripheral nervous systems of patients from diabetes mellitus. Diabetic neuropathy is now thought to be the most common form of peripheral neuropathy that afflicts humankind, with an estimated 220 million people suffering from this malady worldwide.

One of the most commonly encountered forms of diabetes neuropathy is diabetic truncal neuropathy. The pain and motor dysfunction of diabetic truncal neuropathy are often attributed to intrathoracic or intra-abdominal pathology leading to extensive work ups for appendicitis, cholecystitis, renal calculi, and so on. The onset of symptoms will frequently coincide with periods of extreme hypoglycemia or hyperglycemia or with weight loss or weight gain. The patient who presents with diabetic truncal neuropathy will complain of severe dysesthetic pain with patchy sensory deficits in the distribution of the lower thoracic and/ or upper thoracic dermatomes. The pain will often be worse at night and significant sleep disturbance may result, further worsening the patient’s pain symptomatology. The symptoms of diabetic truncal neuropathy will often spontaneously resolve over a period of 6 to 12 months. However, due to the severity of symptoms associated with this condition, aggressive symptomatic relief with pharmacotherapy and neural blockade with local anesthetic and steroid is indicated.

SIGNS AND SYMPTOMS

Physical examination of the patient suffering from diabetic truncal neuropathy will generally reveal minimal physical findings unless there was a history of previous thoracic or subcostal surgery or cutaneous findings of herpes zoster involving the thoracic dermatomes. In contradistinction to the patient suffering from musculoskeletal causes of chest wall and subcostal pain, the patient suffering from diabetic truncal neuropathy does not attempt to splint or protect the affected area. Careful sensory examination of the affected dermatomes may reveal decreased sensation or allodynia. With significant motor involvement of the subcostal nerve, the patient may complain that his or her abdomen bulges out.
The presence of diabetes should raise a high index of suspicion that diabetic truncal neuropathy is present given the high incidence of this condition in patients suffering from diabetes mellitus.

The pain of diabetic truncal neuropathy is neuropathic in nature and is often made worse by poorly controlled blood sugar.

TREATMENT

Pharmacologic Treatment

Antidepressant Agents

Traditionally, the tricyclic antidepressants have been a mainstay in the palliation of pain secondary to diabetic truncal neuropathy. Controlled studies have demonstrated the efficacy of amitriptyline for this indication. Other tricyclic antidepressants, including nortriptyline and desipramine, have also shown to be clinically useful.

Anticonvulsant Agents

The anticonvulsants have long been used to treat neuropathic pain, including diabetic truncal neuropathy. Both phenytoin and carbamazepine have been used with varying degrees of success either alone or in combination with the antidepressants compounds. The anticonvulsant gabapentin has been shown to be highly efficacious in the treatment of a variety of neuropathic painful conditions, including postherpetic neuralgia and diabetic truncal neuropathy. Used properly, gabapentin is extremely well tolerated compared with other drugs, including the antidepressant compounds and anticonvulsants mentioned here that previously were used routinely to treat diabetic truncal neuropathy.

Antiarrhythmic Agents

Mexilitene is an antiarrhythmic compound that has been shown to be possibly effective in the management of diabetic truncal neuropathy. Some pain specialists believe that mexilitene is especially useful in those patients with diabetic truncal neuropathy whose pain manifests primarily as sharp lancinating or burning pain.

Topical Agents

Some clinicians have reported success in the treatment of diabetic truncal neuropathy with topical application of capsaicin. An extract of chili peppers, capsaicin is thought to relieve neuropathic pain by depleting substance P. The side effects of capsaicin include significant burning and erythema and limit the use of this substance by many patients.
Topical lidocaine administered via transdermal patch or in a gel have also been shown to provide short-term relief of the pain of diabetic truncal neuropathy. This drug should be used with caution in patients who are on mexilitene because there is the potential for cumulative local anesthetic toxicity. Whether topical lidocaine will have a role in the long term treatment of diabetic truncal neuropathy remains to be seen.

Neural Blockade

The use of neural blockade with local anesthetic either alone or in combination with steroid has been shown to be useful in the management of both the acute and chronic pain associated with diabetic truncal neuropathy. For truncal neuropathic pain, thoracic epidural or intercostal nerve block with local anesthetic or steroid, or both, may be beneficial. Occasionally, neuroaugmentation via spinal cord stimulation may provide significant relief of the pain of diabetic truncal neuropathy in those patients whom more conservative measures have not helped. Neurodestructive procedures are rarely if ever indicated to treat the pain of diabetic truncal neuropathy because they will often worsen the patient’s pain and cause functional disability.

Low intensity laser therapy as well as a coordinated wellness program is also effective in treating this disorder.

Low Intensity Laser Therapy (LILT)

The low intensity Laser (LILT) sends photons (light) into the injured tissues and can penetrate two to three inches to treat affected areas. It uses a natural enhancement of the cellular machinery that can and has been dynamically measured in published studies to promote healing without burning affected tissue .Once the photons find the injured tissues, they stimulate and energize the cells to repair and strengthen at a remarkable rate. The treatment does not hurt, takes about 30 minutes and is very cost advantageous.

Wellness Program

A wellness program whichindividualizes treatment for age, performance and function has been shown in pilot studies to improve the overall health and well being of the individuals evaluated. A well conceived dietary and supplementary regimen based on scientific age–related decline in certain necessary compounds can improve quality of life, correct the ravages of hormone imbalance, balance critical neurotransmitter function without resorting to powerful drugs for depression that often have unfavorable side-effect profiles and restore vitality and youth in daily exercise routines. Furthermore, when wellness products are utilized with success, individuals often seek less costly interventions including unnecessary surgeries and narcotic options to treat pain. For more information go to www.drpwellness.com.