Effect of various nerve decompression procedures on the functions of distal limbs in streptozotocin-induced diabetic rats: further optimism in diabetic neuropathy

Effect of Lower Extremity Nerve Decompression in Patients With Painful Diabetic Peripheral Neuropathy: The Diabetic Neuropathy Nerve Decompression Randomized, Observation Group and Placebo Surgery-Controlled Clinical Trial

OBJECTIVE

To evaluate the effect of nerve decompression on pain in patients with lower extremity painful diabetic peripheral neuropathy (DPN).

BACKGROUND

Currently, no treatment provides lasting relief for patients with DPN. The benefits of nerve decompression remain inconclusive.

METHODS

This double-blinded, observation and same-patient sham surgery-controlled randomized trial enrolled patients aged 18 to 80 years with lower extremity painful DPN who failed 1 year of medical treatment. Patients were randomized to nerve decompression or observation group (2:1). Decompression-group patients were further randomized and blinded to nerve decompression in either the right or left leg and sham surgery in the opposite leg. Pain (11-point Likert score) was compared between decompression and observation groups and between decompressed versus sham legs at 12 and 56 months.

RESULTS

Of 2987 screened patients, 78 were randomized. At 12 months, compared with controls (n=37), both the right-decompression group (n=22) and left-decompression group (n=18) reported lower pain (mean difference for both: -4.46; 95% CI: -6.34 to -2.58 and -6.48 to -2.45, respectively; P < 0.0001). Decompressed and sham legs equally improved. At 56 months, compared with controls (n=m 14), pain was lower in both the right-decompression group (n=20; mean difference: -7.65; 95% CI: -9.87 to -5.44; P < 0.0001) and left-decompression group (n=16; mean difference: -7.26; 95% CI: -9.60 to -4.91; P < 0.0001). The mean pain score was lower in decompressed versus sham legs (mean difference: 1.57 95% CI: 0.46 to 2.67; P =0.0002).

CONCLUSIONS

Although nerve decompression was associated with reduced pain, the benefit of surgical decompression needs further investigation as a placebo effect may be responsible for part or all of these effects.

Animal Models of Type 2 Diabetes Complications: A Review

Diabetes mellitus is a multifactorial metabolic disease, of which type 2 diabetes (T2D) is one of the most common. The complications of diabetes are far more harmful than diabetes itself. Type 2 diabetes complications include diabetic nephropathy (DN), diabetic heart disease, diabetic foot ulcers (DFU), diabetic peripheral neuropathy (DPN), and diabetic retinopathy (DR) et al. Many animal models have been developed to study the pathogenesis of T2D and discover an effective strategy to treat its consequences. In this sense, it is crucial to choose the right animal model for the corresponding diabetic complication. This paper summarizes and classifies the animal modeling approaches to T2D complications and provides a comprehensive review of their advantages and disadvantages. It is hopeful that this paper will provide theoretical support for animal trials of diabetic complications.

Alteration of Sciatic Nerve Histology and Electrical Function After Compression and After Neurolysis in a Diabetic Rat Model

BACKGROUND

Diabetic rats are more sensitive to nerve entrapment. This study was conducted to evaluate nerve function and histological changes in diabetic rats after nerve compression and subsequent decompression.

METHODS

A total of 35 Wistar rats were included. The experimental group was divided into diabetic sciatic nerve compression group (DSNC, n = 5) and diabetic sciatic nerve decompression group (DSND, n = 20). The DSNC model was created by wrapping a silicone tube circumferentially around the nerve for 4 weeks, and then the DSND group accepted nerve decompression and was followed up to 12 weeks. The DSND group was equally divided into DSND 3 weeks (DSND3), 6 weeks (DSND6), 9 weeks (DSND9), and 12 weeks (DSND12) groups. Five rats were taken as normoglycemic control group (CR, n = 5), and another 5 rats as diabetic control group (DM, n = 5). The mechanical hyperalgesia of rats was detected by Semmes-Weinstein nylon monofilaments (SWMs) and by motor nerve conduction velocity (MNCV). These 2 physiological indicators and histology of sciatic nerves were compared among different groups.

RESULTS

The SWM measurements improved toward normal values after decompression. The SWM value was significantly lower (more normal) in the DSNC groups than in the DSND group (P < 0.05). The MNCV was 53.7 ± 0.8 m/s in the CR group, whereas it was 28.4 ± 1.0 m/s in the DSNC group (P < 0.001). Six weeks after decompression, the MNCV was significantly faster than that in the DSNC group (P < 0.001). Histological examination demonstrated chronic nerve compression, which responded toward normal after decompression, but with degree of myelination never recovering to normal.

CONCLUSIONS

Chronic compression of the diabetic sciatic nerve has measureable negative effects on sciatic nerve motor nerve function, associated with a decline of touch/pressure threshold and degeneration of myelin sheath and axon. Nerve decompression surgery can reverse these effects and partially restore nerve function.

Nerve decompression and neuropathy complications in diabetes: Are attitudes discordant with evidence?

External neurolysis of the nerve at fibro-osseous tunnels has been proprosed to treat or prevent signs, symptoms, and complications in the lower extremity of diabetes patients with sensorimotor polyneuropathy. Nerve decompression is justified in the presence of symptomatic compressed nerves in the several fibro-osseous tunnels of the extremities, which are known to be frequent in diabetes. Quite a body of literature has accumulated reporting results after such nerve decompression in the leg, describing pain relief and sensibility improvement, as well as balance recovery, diabetic foot ulcer prevention, curtailed ulcer recurrence risk, and amputation avoidance. Historical academic hesitance to endorse surgical treatments for pain and numbness in diabetes was based primarily on the early retrospective reports' potential for bias and placebo effects, and that the hypothetical basis for surgery lies outside the traditional etiology paradigm of length-dependent axonopathy. This reticence is here critiqued in view of recent studies using objective, measured outcome protocols which nullify such potential confounders. Pain relief is now confirmed with Level 1 studies, and Level 2 prospective information suggests protection from initial diabetic foot ulceration and most neuropathic ulcer recurrences. In view of the potential for nerve decompression to be useful in addressing some of the more difficult, expensive, and life altering complications of diabetic neuropathy, this secondary compression thesis and operative treatment methodology may deserve reassessment.

Effects of decompression on behavioral, electrophysiologic, and histomorphologic recovery in a chronic sciatic nerve compression model of streptozotocin-induced diabetic rats

Purpose

To determine susceptibility to decompression surgery in diabetic and nondiabetic peripheral neuropathy using a chronic compression neuropathy model.

Materials and methods

Twenty-four streptozotocin-induced diabetic rats were randomly divided into three groups: group I, chronic compression of the left sciatic nerve for 4 weeks with decompression; group II, similar without decompression; and group III, sham exposing the sciatic nerve only. The other 24 nondiabetic rats were assigned to groups IV–VI, which received compression–decompression, compression, and the sham operation, respectively. Mixed-nerve-elicited somatosensory evoked potentials (M-SSEPs) and compound muscle action potentials (CMAPs) were measured to verify the compression neuropathy in the posttreatment follow-up. Behavioral observations in thermal hyperalgesia tests were quantified before electrophysiologic examinations. Treated and contralateral nerves were harvested for histomorphologic analysis.

Results

Chronic compression of sciatic nerve induced significant reduction of amplitude and increment of latency of M-SSEP and CMAP in both diabetic and nondiabetic rats. Diabetic group changes were more susceptible. Decompression surgery significantly improved both sensory and motor conduction, thermal hyperalgesia, and the mean myelin diameter of the rat sciatic nerve in both diabetic and nondiabetic groups. Near full recovery of motor and sensory function occurred in the nondiabetic rats, but not in the diabetic rats 8 weeks postdecompression.

Conclusion

Behavioral, electrophysiologic, and histomorphologic findings indicate that decompression surgery is effective in both diabetic and nondiabetic peripheral neuropathy.

Susceptibility of nerve in diabetes to compression: implications for pain treatment

BACKGROUND

Twenty-five years ago, it was hypothesized that the peripheral nerve in the patients with diabetes is susceptible to chronic compression. If this hypothesis were true, then decompression of multiple, compressed peripheral nerves, in the patient with diabetic neuropathy, would restore sensation and relieve pain, thereby relieving the traditionally observed clinical course leading to ulceration and amputation. This article reviews research related to this hypothesis and the obtained clinical results.

METHODS

The basic science models necessary to establish the neurophysiological basis proving this hypothesis are reviewed. Translational retrospective and prospective clinical studies related to this hypothesis are reviewed. Implications for therapeutic change and healthcare costs are reviewed.

RESULTS

Basic science models demonstrated that the peripheral nerve in diabetes is susceptible to chronic compression. Anatomic studies identified appropriate locations for decompression of nerves in the lower extremity. Clinical outcomes demonstrated significantly decreased ulceration and amputation, significant decrease in admission to hospitals for chronic foot infection, and a significant decrease in pain and increased sensation in patients with diabetes and chronic nerve compression following a Dellon Triple Decompression surgery.

CONCLUSIONS

The approach described in this review, to identifying chronic nerve compression in the patients with diabetes and subsequent decompression of these nerves, has permitted a significant increase in foot sensibility with the expected decrease in pain and decrease in ulceration and amputation. There is a significant healthcare cost benefit to this approach. At present, this approach is being used in more than 20 countries.

Biologic Basis of Nerve Decompression Surgery for Focal Entrapments in Diabetic Peripheral Neuropathy

The most recent (2011) National Diabetes Fact Sheet states the combined diagnosed and undiagnosed number of diabetes cases in the United States is approaching 25 million, and another 79 million are prediabetic. Of the diabetes patients, 60-70% suffer from mild to severe neuropathy. This combined loss of sensory and motor control in diabetic limbs is usually considered an irreversible, progressive process. Patients suffering from these losses are at a significantly higher risk for development of foot ulceration, frequently leading to infection and partial or major limb amputation. However, a review of focal nerve entrapment surgical decompression literature suggests that several diabetic sensorimotor polyneuropathy (DSPN) symptoms and complications are potentially partially reversible or preventable. Decompression surgery represents a paradigm shift in treatment protocols because it both relieves pain and restores protective sensation, while providing significant protection against a cascade of serious foot complications. This review surveys current research regarding the biological basis for diabetic focal entrapment neuropathy. Metabolic dysfunction related to aldose reductase, oxidative stress, and advanced glycation end products are considered and correlated to peripheral nerve enlargement and entrapment. In addition, observational studies correlated to that biological basis are presented as well as surgical outcomes illustrating the effect of decompression on DSPN symptomatic relief, nerve function, and protection against complications.

Reconsidering nerve decompression: an overlooked opportunity to limit diabetic foot ulcer recurrence and amputation

Nerve decompression for relief of subjective diabetic sensorimotor polyneuropathy pain and numbness has been labeled of "unknown" benefit. Objective outcomes in treatment and prevention of diabetic foot complications are reviewed. There is growing evidence that plantar foot ulceration and recurrence in high-risk feet are minimized with this operation. Avoiding neuropathic and neuroischemic ulcer wounds should theoretically reduce amputations and perhaps mortality risk. Protective effects are hypothesized to act via relief of neuro-vascular entrapment, thereby improving neurally modulated tissue homeostasis factors. Nerve decompression deserves considerable research attention to understand its role in limiting foot complications. Its apparent benefits challenge the paradigm that diabetic neuropathy is a purely length-dependent axonopathy and may necessitate appreciation of superimposed nerve entrapment as an significant operant factor.

The effect of perineurotomy on nerve regeneration in diabetic rats

BACKGROUND

One of the main causes of diabetic neuropathy is endoneurial edema, which increases the internal pressure of the perineurium, which has a tight structure. The treatment used to reduce internal pressure is perineurotomy, in which a surgical incision is made into the perineurium.

METHODS

Forty male Sprague-Dawley rats were used in the study. They were classified into four groups. Streptozotocin-induced diabetes was created in groups III and IV. The sciatic nerve was transected and repaired epineurally in all groups. Perineurotomy was performed additionally in group II and IV to the sciatic, peroneal, tibial, and sural nerves from the most proximal side to their most distal ends. The sciatic function indices were calculated for functional assessment. Light and electron microscopic evaluations were performed for morphometric assessment. In addition, the myelinated and degenerated fibers were counted in all groups.

RESULTS

The sciatic function indices of the diabetic perineurotomy group were found to be significantly higher than those of the other groups (p < 0.05). Based on the myelinated fiber counts, there was insignificant difference between group I and group II, whereas the difference was significant (p < 0.05) between group III and group IV. Presence of peripheric nerves in light microscopic evaluation revealed normal characteristics of myelinated fibers in group I and group II. The myelinated axon profile in group IV was similar to that of groups I and II in electron microscopic evaluation.

CONCLUSION

It is concluded that perineurotomy may be established as a useful adjunctive procedure for nerve repair in diabetic patients.

The diagnosis and treatment of heel pain: a clinical practice guideline-revision 2010

Heel pain, whether plantar or posterior, is predominantly a mechanical pathology although an array of diverse pathologies including neurologic, arthritic, traumatic, neoplastic, infectious, or vascular etiologies must be considered. This clinical practice guideline (CPG) is a revision of the original 2001 document developed by the American College of Foot and Ankle Surgeons (ACFAS) heel pain committee.

Nerve decompression surgery as treatment for peripheral diabetic neuropathy: literature overview and awareness among medical professionals

Peripheral diabetic neuropathy (PDN) is one of the major complications arising in patients with diabetes. Since PDN is traditionally considered an irreversible disorder, treatment has been aimed to prevent the development of complications. In a novel concept, however, it is postulated that decompression surgery of the affected nerve may reverse the natural course of PDN. In this review, we will discuss experimental and human studies that addressed the value of nerve decompression surgery in PDN. Furthermore, we report on the awareness of this novel treatment strategy among medical professionals that are primarily involved in diabetes care.

Decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy

BACKGROUND

Symmetrical peripheral neuropathy is a common complication of diabetic neuropathy. No treatments are known to be effective for progressive pain and sensory loss associated with diabetic neuropathy. Alternative effective treatment strategies have been sought.

OBJECTIVES

To systematically review the evidence from randomized controlled trials concerning the role of decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Trials Register (May 2006), CENTRAL (The Cochrane Library, Issue 2 2006), MEDLINE from (January 1966 to August 2006), EMBASE (from January 1980 to August 2006), LILACS (from January 1982 to August 2006), and CINAHL (from January 1982 to August 2006).

SELECTION CRITERIA

We included all randomized or quasi-randomized controlled human trials in which any form of decompressive surgery of the lower limbs nerves had been used to treat diabetic symmetrical distal polyneuropathy (DSDP) compared with no treatment or medical therapy. Patients with DSDP were included if they had decompression (with or without neurolysis) of at least two of the following nerves in both lower limbs, for the treatment of DSDP: the posterior tibial nerve (including calcaneal, medial and lateral plantar nerves), deep peroneal nerve at the ankle, common peroneal nerve at the knee, lateral femoral cutaneous nerve and sural nerves in the posterior calf region. The primary outcome measure was the change in pain measured by the visual analogue scale (VAS) between the baseline and a follow-up period of greater than three months.

DATA COLLECTION AND ANALYSIS

We identified 142 publications from the above search strategies. The three authors of this manuscript reviewed abstracts of all papers independently. Only eight of these were considered relevant to the question at hand. The data from these 8 studies were entered onto standardized data extraction forms. We planned to use Review Manager to pool the results from appropriate studies comparing the same treatments; dichotomous outcomes to obtain pooled relative risks (RR); measured outcomes to obtain pooled weighted mean differences; and a fixed-effect analysis unless there was evidence of serious heterogeneity between studies sufficient to justify the use of random-effects analysis.

MAIN RESULTS

This review failed to identify a single randomized controlled trial or any other well designed prospective study controlling for the non-operated limb that showed improvements in pre defined end points after decompressive surgery.

AUTHORS' CONCLUSIONS

The results of this review suggest that the role of decompressive surgery for diabetic symmetric distal neuropathy is unproven.

Surgical treatment of superimposed nerve compressions in hepatitis C neuropathy

The plastic surgeon's usual involvement in patients with hepatitis C is most frequently limited to an inner city population with hand and forearm abscesses from intravenous drug use or to incidences of needle-stick injury in the operating room when the patient is hepatitis C positive. Hand surgeons and peripheral nerve surgeons often treat patients with underlying neuropathies who have superimposed overlying nerve compressions such as carpal tunnel syndrome. We have applied this experience to a patient with underlying peripheral neuropathy associated with Hepatitis C and clinical evidence of overlying lower extremity nerve compressions. We believe that she is the first successful surgical treatment of peripheral nerve compressions in a patient with hepatitis C-associated neuropathy, documented by noninvasive neurosensory testing.

Diabetic neuropathy: medical and surgical approaches

This article establishes the most critical, practical, and successful treatment options and their controversies for the practicing clinician caring for the patient with symptomatic diabetic neuropathy from the available literature.

Effect of Early Nerve Release on the Progression of Neuropathy in Diabetic Rats

Diabetic neuropathy renders the peripheral nerves to be more susceptible to compression at potential entrapment sites. We evaluated the effects of "prophylactic" decompression procedures on the progression of diabetic neuropathy in an experimental model. Thirty diabetic Zucker rats were studied. Group I, II, and III rats were followed up for 12 weeks and IV, V, and VI rats for 24 weeks. Group III and VI rats served as short- and long-term controls without any surgical intervention. Group I and IV rats had tarsal tunnel release (TTR); group II and V rats had TTR and peroneal nerve release (PNR) procedures on their left legs. Nerve function was assessed by pinprick, toe spread tests, sciatic function index (SFI), somatosensory evoked potential (SSEP) analysis, and gastrocnemius muscle wet weight measurements.SFI analysis revealed a statistically significant difference between the combined TTR-PNR and nonoperative control groups at both short- and long-term follow-up (P </= 0.01). SSEP result analysis of operated left and nonoperated right sides revealed a statistically significant difference in P1 latency values at both short- and long-term follow-up (P < 0.05). We confirmed beneficial effects of decompression procedures at early onset of diabetes before the metabolic nerve injury advanced into an axonal loss.

Diabetic neuropathy

Perspectives on the News commentaries are now part of a new, free monthly CME activity. The Mount Sinai School of Medicine, New York, New York, is designating this activity for 2.0 AMA PRA Category 1 credits. If you wish to participate, review this article and visit www.diabetes.procampus.net to complete a posttest and receive a certificate. The Mount Sinai School of Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

Comparison of clinical evaluation and neurosensory testing in the early diagnosis of superimposed entrapment neuropathy in diabetic patients

Diabetic patients are more susceptible to the development of entrapment neuropathy than nondiabetics. Since these patients suffer from a slowly progressing diabetic polyneuropathy, standard neurosensory and motor tests of nerve function are not sufficient in the diagnosis of superimposed nerve compression. This is most evident in the early stages of compression when quantitative diagnosis is important for making decisions on surgical decompression. We evaluated the validity of computer-assisted pressure-specified sensory device (PSSD) testing in the early detection of superimposed entrapment in diabetic neuropathy in comparison with standard clinical tests. Twenty-five diabetic patients with complaints of peripheral nerve dysfunction were evaluated by clinical tests and PSSD. Out of those, nerve entrapment was detected in 15 patients (60%) (9 in late and 6 in early stage) by neurosensory PSSD testing. Standard clinical tests were confirmative in 33.3% of these cases (44% of late and 16.7% of early stage). Out of 144 evaluated nerves, 50 were diagnosed with entrapment (24 in late and 26 in early stage) using PSSD. Clinically, diagnosis was confirmed in 16% of entrapped nerves (20.8% of late and 11.5% of early stage). Average diabetes duration in patients with entrapment diagnosed using PSSD was significantly shorter than for those diagnosed clinically (4.14 +/- 2.04 vs. 7.2 +/- 1.3, respectively; P = 0.005). Among evaluated factors, mean age and diabetes duration were found to be significantly shorter in patients with entrapment than in those with advanced diffused changes (54.47 +/- 13.07 vs. 67.10 +/- 14.2; P = 0.019 and 5.33 +/- 3.74 vs.14.22 +/- 8.17; P = 0.006; respectively). Our results revealed higher sensitivity of PSSD in comparison with standard clinical tests in the detection of early-stage entrapment in patients with diabetes. To assess accuracy of PSSD in the proper patients' qualification for surgery, further prospective, postoperative studies are needed.

From there to here: a personal viewpoint after three decades of neuropathy research

Currently there is unprecedented interest in research, writing, and clinical experience related to lower extremity peripheral nerve surgery. Its time is here, now. Application of the concepts for diagnosis and treatment of nerve compression, painful neuroma, and neuropathy has been a direct extension from the upper extremity to the lower extremity. By the end of 2005, there were more than a dozen studies demonstrating that the basic neuropathy causes metabolic changes that render the peripheral nerve susceptible to chronic nerve compressions. My hypothesis continues to assert that surgical decompression of known sites of compression can relieve symptoms of neuropathy that are caused by superimposed nerve compressions.

Chemotherapy-induced neuropathy

Increasingly, surgeons are becoming aware of the successful treatment of symptomatic peripheral neuropathy by surgical decompression of peripheral nerves. Armed with the knowledge that patients can have underlying neuropathy with overlying anatomic compressions, surgeons have affected improvement in diabetes-induced neuropathy, neuropathy of unknown etiology, and chemotherapy-induced neuropathy. This article details the most well-known culprits in chemotherapy-induced neuropathy and discusses the putative mechanisms of action, medical management, and surgical data.

Axonal and extracellular matrix responses to experimental chronic nerve entrapment

We have analyzed the ultrastructural and histopathological changes that occur during experimental chronic nerve entrapment, as well as the immunohistochemical expression of chondroitin sulfate proteoglycan (CSPG). Adult hamsters (n = 30) were anesthetized and received a cuff around the right sciatic nerve. Animals survived for varying times (5 to 15 weeks) being thereafter perfused transcardially with fixative solutions either for immunohistochemical or electron microscopic procedures. Experimental nerves were dissected based upon the site of compression (proximal, entrapment and distal). CSPG overexpression was detected in the compressed nerve segment and associated with an increase in perineurial and endoneurial cells. Ultrastructural changes and data from semithin sections were analyzed both in control and compressed nerves. We have observed endoneurial edema, perineurial and endoneurial thickening, and whorled cell-sparse pathological structures (Renaut bodies) in the compressed nerves. Morphometrical analyses of myelinated axons at the compression sites revealed: (a) a reduction both in axon sectional area (up to 30%) and in myelin sectional area (up to 80%); (b) an increase in number of small axons (up to 60%) comparatively to the control group. Distal segment of compressed nerves presented: (a) a reduction in axon sectional area (up to 60%) and in myelin sectional area (up to 90%); (b) a decrease in axon number (up to 40%) comparatively to the control data. In conclusion, we have shown that nerve entrapment is associated with a local intraneural increase in CSPG expression, segmental demyelination, perineurial and endoneurial fibrosis, and other histopathological findings.

Prognostic Ability of Tinel Sign in Determining Outcome for Decompression Surgery in Diabetic and Nondiabetic Neuropathy

During the past 12 years, 6 studies reported restoration of sensation and relief of pain in the foot by decompression of the tibial nerve and its distal branches in diabetic neuropathy. Although a positive Tinel sign related to favorable outcomes in some of the reports, this relationship was not evaluated specifically. In this study, the presence of the Tinel sign, positive or negative, over the tibial nerve was recorded in 46 patients with diabetic neuropathy and in 40 patients with idiopathic neuropathy. Outcomes were dichotomized into either a good/excellent or failure/poor category. Postoperative data were analyzed at 1 year. In diabetic neuropathy, the presence of a positive Tinel sign had a sensitivity of 88%, a specificity of 50%, and a positive predictive value of 88% in identifying patients who would have a good/excellent outcome. In idiopathic neuropathy, the presence of a positive Tinel sign had a sensitivity of 95%, a specificity of 56%, and a positive predictive value of 93% in identifying patients who would have a good/excellent outcome. It is concluded that a positive Tinel sign is a reliable indicator of successful outcome from decompression of the tibial nerve in patients with diabetes with symptomatic neuropathy, and in patients with symptomatic idiopathic neuropathy.

Changing the Natural History of Diabetic Neuropathy: Incidence of Ulcer/Amputation in the Contralateral Limb of Patients With a Unilateral Nerve Decompression Procedure

The natural history of diabetes neuropathy is progressive and irreversible loss of sensibility in the feet, leading to ulceration and/or amputation in 15% of patients. The prevalence of neuropathy is more than 50% in those who have been diabetic for 20 years. Decompression of the tibial and peroneal nerves in those with diabetic neuropathy improves sensation in 70% of patients. The impact of this surgery on the development of ulcers and amputations in both the operated and the contralateral, nonoperated limb was evaluated in a retrospective analysis of 50 patients with diabetes a mean of 4.5 years (range, 2-7 years) from the date of surgery. No ulcers or amputations occurred in the index limb of these patients. In contrast, there were 12 ulcers and 3 amputations in 15 different patients in contralateral limbs. This difference was significant at P < 0.001. It is concluded that decompression of lower extremity nerves in diabetic neuropathy changes the natural history of this disease, representing a paradigm shift in health care costs.

New method for evaluation of cutaneous sensibility in diabetic feet: preliminary report

Diabetic neuropathy is an important complication of the disease, responsible for ulceration and amputation of the foot. Prevention of these problems is difficult mainly because there is no method to correctly access sensibility on the skin of the foot. The introduction of the Pressure-Specified Sensory Device (PSSD) in the last decade made possible the measurement of pressure thresholds sensed by the patient, such as touch, both static and in movement, on a continuous scale. This paper is the first in Brazil to report the use of this device to measure cutaneous sensibility in 3 areas of the foot: the hallux pulp, the calcaneus, and the dorsum, which are territories of the tibial and fibular nerves.

METHOD

Non-diabetic patients were measured as controls, and 2 groups of diabetic patients - with and without ulcers - were compared. The PSSD was used to test the 3 areas described above. The following were evaluated: 1 PS (1-point static), 1 PD (1-point dynamic), 2 PS (2-points static), 2 PD (2-points dynamic).

RESULTS

The diabetic group had poorer sensibility compared to controls and diabetics with ulcers had poorer sensibility when compared to diabetics without ulcers. The differences were statistically significant (P <.001).

CONCLUSION

Due to the small number of patients compared, the results should be taken as a preliminary report.

Diabetic neuropathy: review of a surgical approach to restore sensation, relieve pain, and prevent ulceration and amputation

Diabetic neuropathy occurs in a stocking and glove distribution consistent with a systemic metabolic disease. Historically, this concept led to the conclusion that the only role for surgery in a patient with diabetic neuropathy is for treatment of wounds, amputation, or reconstruction of a Charcot foot. This article reviews the basic scientific and clinical research that support the concepts that metabolic neuropathy renders the peripheral nerve susceptible to compression in patients with diabetes and that decompression of lower extremity peripheral nerves in these patients can relieve pain, restore sensation, and prevent ulceration and amputation.