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.
Pfeifer
M A
MA
Diabetes Research and Treatment Center, Southern Illinois University, Springfield 61702.
Ross
D R
DR
Schrage
J P
JP
Gelber
D A
DA
Schumer
M P
MP
Crain
G M
GM
Markwell
S J
SJ
Jung
S
S
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