A highly successful and novel model for treatment of chronic painful diabetic peripheral neuropathy.
OBJECTIVE
To investigate why, in spite of a vast variety of treatment agents, the alleviation of pain in patients with diabetic neuropathy is difficult. Previous studies have not used a treatment algorithm based on anatomic site and neuropathophysiological source of the neuropathic pain.


METHODS
A model that categorizes the types of pain into three groups (superficial, deep, and muscular) was applied in 75 diabetic patients with chronic (> 12 mo) painful distal symmetrical polyneuropathy in a controlled case series. Twenty-two patients were untreated and 53 patients were treated with imipramine +/- mexiletine for deep pain, capsaicin for superficial pain, and stretching exercises and metaxalone +/- piroxican for muscular pain. Each type of pain was scored separately on a scale of 0 (none) to 19 (worst), and the total of all three types was used as an index of overall pain. Ability to sleep through the night was scored by a scale of 1 (never) to 5 (always).


RESULTS
No significant differences were observed in initial pain scores, sleep scores, demographics, biochemistries, or physical findings between the two groups. After 3 mo a significant improvement in scores was noted in the treated but not the untreated patients. In addition, a significant difference was found in the change of scores between the treated and untreated patients: total pain (-18 +/- 2 vs. 0 +/- 2), deep pain (-7 +/- 1 vs. 0 +/- 1), superficial pain (-5 +/- 1 vs. 0 +/- 1), muscular pain (-6 +/- 1 vs. 0 +/- 1), and sleep (1.2 +/- 0.2 vs. 0.2 +/- 0.2), all P < 0.0001. In treated patients 21% became pain-free (total pain < 2), 66% had improvement (decrease in total pain > 5, but not total elimination of painful symptoms), and 13% were considered treatment failures (a decrease in total pain of < or = 5). This compares with 0 (P < 0.02), 10 (P < 0.0001), and 90% (P < 0.0001), respectively, in the untreated patients.


CONCLUSIONS
This study presents a new rationale and hypothesis for the successful treatment of chronic painful diabetic peripheral neuropathy. It uniquely bases the treatment algorithm on the types and sources of the pain.
Diabetes Research and Treatment Center, Southern Illinois University, Springfield 61702.
M A
MA
Pfeifer
D R
DR
Ross
J P
JP
Schrage
D A
DA
Gelber
M P
MP
Schumer
G M
GM
Crain
S J
SJ
Markwell
S
S
Jung
D000700:Analgesics / Q000627:therapeutic use*; D002211:Capsaicin / Q000627:therapeutic use; D003929:Diabetic Neuropathies / Q000503:physiopathology* / Q000628:therapy*; D005081:Exercise Therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007099:Imipramine / Q000627:therapeutic use; D008297:Male; D008801:Mexiletine / Q000627:therapeutic use; D008875:Middle Aged; D008959:Models, Neurological; D009132:Muscles / Q000294:innervation* / Q000503:physiopathology; D010080:Oxazoles / Q000627:therapeutic use; D023303:Oxazolidinones; D010146:Pain / Q000145:classification / Q000503:physiopathology; D059408:Pain Management; D010147:Pain Measurement; D010894:Piroxicam / Q000627:therapeutic use
D000700:Analgesics; D002211:Capsaicin; D006442:Glycated Hemoglobin; D007099:Imipramine; D008801:Mexiletine; D010080:Oxazoles; D023303:Oxazolidinones; D010894:Piroxicam; C011301:metaxalone