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

Does Lower Extremity Nerve Decompression Surgery Improve Quality of Life?

BACKGROUND

Entrapment neuropathies are more prevalent in patients with diabetes than in healthy patients. The aim of this study was to assess the effects of lower extremity nerve decompression surgery on quality of life and clarify predictors of this surgical outcome and the incidence of surgical site problems.

METHODS

Patients who underwent lower extremity nerve decompression surgery between September of 2017 and March of 2019 were followed prospectively at the outpatient clinic of University Medical Center Utrecht. The common, superficial, and deep peroneal nerve and tibial nerve at the tarsal tunnel and soleal sling were decompressed if an entrapment was diagnosed. The primary study outcome was quality of life as measured by the Norfolk Quality of Life-Diabetic Neuropathy questionnaire. Secondary outcomes of interest were change in Michigan Neuropathy Screening Instrument score, predictors of the Norfolk score at follow-up, and the occurrence of complications.

RESULTS

Sixty patients underwent surgery (45 unilateral, 15 bilateral), with a median postoperative follow-up of 13.0 months (interquartile range, 7.3 to 18.0 months). Quality of life improved significantly in this period of observation [baseline median, 46.0 (34.0 to 62.0) versus follow-up median, 37.0 (20.0 to 60.0); p = 0.011], as did Michigan Neuropathy Screening Instrument scores [7.0 (5.0 to 9.0) versus 3.0 (0.0 to 6.5); p < 0.01]. Predictors of quality of life were a higher baseline quality of life score [β, 0.59 ( p = 0.001)], longer follow-up time [β, 2.34 ( p < 0.001)], and hypertension [β, 16.38 ( p = 0.03)]. A total of 26.7 percent of patients had surgical site problems, including wound infections (18.3 percent).

CONCLUSIONS

Lower extremity nerve decompression surgery significantly improves quality of life by reducing neuropathy symptoms in patients with lower extremity nerve compressions. Attention should be given to lowering the risk of wound complications.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

An update on imaging of tarsal tunnel syndrome

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve (TN) within the tarsal tunnel (TT) at the level of the tibio-talar and/or talo-calcaneal joints. Making a diagnosis of TTS can be challenging, especially when symptoms overlap with other conditions and electrophysiological studies lack specificity. Imaging, in particular MRI, can help identify causative factors in individuals with suspected TTS and help aid surgical management. In this article, we review the anatomy of the TT, the diagnosis of TTS, aetiological factors implicated in TTS and imaging findings, with an emphasis on MRI.

Nerve Decompression and Distal Transtibial Amputation

Approximately 20% of patients with diabetic peripheral neuropathy (DPN) endorse painful sensations such as prickling, stabbing, and burning pain that reflect small-fiber involvement. Although glycemic control is crucial to delay the onset and progression of DPN, there have been many reports on the use of decompression nerve surgery to aid in the treatment of DPN.

Lower Extremity Nerve Decompression for Diabetic Peripheral Neuropathy: A Systematic Review and Meta-analysis

Background:

Diabetic peripheral neuropathy (DPN) is a leading cause of morbidity. This systematic review and meta-analysis evaluate the efficacy of lower extremity nerve decompression in reducing DPN symptoms and complications.

Methods:

A database search was performed using Medline, Embase, Google Scholar, and Cochrane Central Register of Controlled Trials. Articles addressing surgical decompression of lower limb peripheral nerves in patients with diabetes were screened for inclusion. Two independent reviewers undertook the assessment. Methodological quality measures were the Cochrane risk of bias and Newcastle-Ottawa scale.

Results:

The pooled sample size from 21 studies was 2169 patients. Meta-analysis of 16 observational studies showed significant improvement in the visual analog scale (VAS) (P < 0.00001) and two-point discrimination (P = 0.003), with strong reliability. Decompression of the tarsal tunnel region had the highest improvement in VAS [MD, 6.50 (95% CI, 3.56–9.44)]. A significant low-risk ratio (RR) of ulcer development and lower limb amputation was detected (P < 0.00001). Lowest RR of ulcer development was detected with tarsal tunnel release [RR, 0.04 (95% CI, 0.00–0.48)]. Improvements in VAS, two-point discrimination, and nerve conduction velocity were nonsignificant in the meta-analysis of five randomized controlled trials (RCTs). The RCT analysis was limited to only two studies for each outcome.

Conclusions:

Meta-analysis of observational studies highlights the efficacy of lower extremity nerve decompression in reducing DPN symptoms, ulcerations, and amputations. Releasing the tibial nerve in the tarsal tunnel region was the most effective observed procedure. Nevertheless, high-quality RCTs are required to support the utility of this intervention in DPN.

Cost-Effectiveness of Lower Extremity Nerve Decompression Surgery in the Prevention of Ulcers and Amputations: A Markov Analysis

BACKGROUND

The costs and health effects associated with lower extremity complications in diabetes mellitus are an increasing burden to society. In selected patients, lower extremity nerve decompression is able to reduce symptoms of neuropathy and the concomitant risks of diabetic foot ulcers and amputations. To estimate the health and economic effects of this type of surgery, the cost-effectiveness of this intervention compared to current nonsurgical care was studied.

METHODS

To estimate the incremental cost-effectiveness of lower extremity nerve decompression over a 10-year period, a Markov model was developed to simulate the onset and progression of diabetic foot disease in patients with diabetes and neuropathy who underwent lower extremity nerve decompression surgery, compared to a group undergoing current nonsurgical care. Mean survival time, health-related quality of life, presence or risk of lower extremity complications, and in-hospital costs were the outcome measures assessed. Data from the Rotterdam Diabetic Foot Study were used as current care, complemented with information from international studies on the epidemiology of diabetic foot disease, resource use, and costs, to feed the model.

RESULTS

Lower extremity nerve decompression surgery resulted in improved life expectancy (88,369.5 life-years versus 86,513.6 life-years), gain of quality-adjusted life-years (67,652.5 versus 64,082.3), and reduced incidence of foot complications compared to current care (490 versus 1087). The incremental cost-effectiveness analysis was -€59,279.6 per quality-adjusted life-year gained, which is below the Dutch critical threshold of less than €80,000 per quality-adjusted life-year.

CONCLUSIONS

Decompression surgery of lower extremity nerves improves survival, reduces diabetic foot complications, and is cost saving and cost-effective compared with current care, suggesting considerable socioeconomic benefit for society.

Tarsal tunnel release restores sensations in sole for diabetic sensorimotor polyneuropathy

BACKGROUND

Diabetic sensorimotor polyneuropathy (DSPN) is the commonest form of neuropathy. Loss of sensations in sole leads to diabetic foot ulcers (DFU) and its complications. Surgical decompression has been used in the treatment of diabetic peripheral neuropathy, however; its effectiveness has been questioned.Purpose of this study was to evaluate the sensory recovery in sole after tarsal tunnel decompression (TTD) in patients having DSPN.

METHODS

Thirteen patients (Age28-70 years, average 35.57 years; 7 Males, 6 Females; 20 feet) with DSPN and positive Tinel's sign over the tarsal tunnel were included in the study. Pre and post-operative sensory tests performed on the sole included tests for touch, pain, temperature, pressure, vibration perception threshold (VPT) and two-point discrimination (2-PD). Results were classified as per British Medical Research Council (MRC) scoring system.

RESULTS

-Sixteen feet were followed-up for 6 months. In all feet perception of touch, pain and pressure recovered. Temperature perception recovered in 75% feet. VPT came to normal range (16.81V) from 40.37 V and 2-PD came down to average of 6.0 mm from preoperative average of11.2 mm.MRC scale improved from S0 in 5 feet and S2 in 15 feet to S₃₊ in all 16 feet.There were no ulcers or amputation in operated limbs during follow up period of 6 months.

CONCLUSIONS

TTD improves plantar sensations in diabetic neuropathy and prevents ulcers and its related complications.

The natural history of tarsal tunnel syndrome in diabetic subjects

INTRODUCTION

Tibial nerve entrapment is highly prevalent in diabetic subjects, resulting in significantly more neuropathic complaints and concomitant sensory disturbances. The study aim was to assess the impact of tarsal tunnel syndrome (TTS) and sensory loss at baseline on incident diabetic foot ulceration (DFU) in diabetic patients, since decompressing the tibial nerve might change the natural history of the disease.

METHODS

In this study, 113 subjects with TTS (69 bilateral, 23 left-sided and 21 right-sided) participating in the prospective Rotterdam Diabetic Foot Study were compared to 303 diabetic controls without TTS, regarding incident DFU. Kaplan-Meier analysis and Cox's regression analysis were used to determine the independent hazard of baseline variables for new DFU.

RESULTS

The median observation period was 836.5 days (IQR, 459-1077.8). In bilateral TTS, 17.4% (95% CI: 8.4-26.3%) of subjects experienced DFU versus 8.3% (95% CI: 5.1-11.6%) in controls (left or right) during follow-up (p = 0.0036). In left-sided TTS, no subjects versus 6.2% (95% CI: 3.4-9.0%) in controls had DFUs (p = 0.243). Incident ulceration was seen in 14.3% (95% CI: -0.7% to -29.3%) of right-sided TTS subjects versus 4.1% (95% CI: 1.5-6.3%) in controls (p = 0.034). Besides HbA1c, diminished sensation at the hallux independently increased the risk of ulceration, in patients with (HR: 4.692, p = 0.003) and without (HR: 2.307, p = 0.002) prior DFU.

DISCUSSION

Elevated sensory thresholds in TTS render diabetic patients at a higher risk for DFU. With effective surgery, TTS is likely to be an amenable factor to potentially prevent diabetic foot disease and thereby reduce amputation risk.

LEVEL OF EVIDENCE

II.

Analysis of Surgical Cases of Tarsal Tunnel Syndrome in Our Department: Case Series and Literature Review

Background:

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy in which the tibial nerve is compressed within the tarsal tunnel and causes sensory disturbance in the sole of the foot. In this manuscript, we summarized our early surgical cases of TTS.

Materials and Methods:

Six feet in five patients with TTS were treated surgically. The patients were aged 31–70 years (mean 53.1 years), and all of them complained of pain or dysesthesia of the sole of the foot sparing the heel. Magnetic resonance imaging (MRI) and nerve conduction test were performed preoperatively. In surgery, flexor retinaculum was dissected (tarsal tunnel opening [TTO]), the posterior tibial nerve was freed from the arteriovenous complex (neurovascular decompression [NVD]), and fascia of the abductor hallucis muscle was excised to decompress the medial and lateral plantar nerve (releasing fascial of abductor hallucis muscle [RFAH]).

Results:

Preoperative MRI confirmed that all seven cases were idiopathic TTS. Moreover, NCD demonstrated delayed sensory conduction velocity but not delayed distal motor latency. Surgical decompression was beneficial in 5 feet. The recurrence of symptoms was found in one case within 1 postoperative month.

Conclusion:

Surgical treatment for idiopathic TTS with TTO, NVD, and RFAH was generally good. However, symptoms recurred in one instance. Some methods to prevent adhesion and granulation in the reconstructed tarsal tunnel should be considered.

Comparison between direct repair and human acellular nerve allografting during contralateral C7 transfer to the upper trunk for restoration of shoulder abduction and elbow flexion

Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct repair can only be performed in some selected cases, and partial procedures still require autografts, which are the gold standard for repairing neurologic defects. As symptoms often occur after autografting, human acellular nerve allografts have been used to avoid concomitant symptoms. This study investigated the quality of shoulder abduction and elbow flexion following direct repair and acellular allografting to evaluate issues requiring attention for brachial plexus injury repair. Fifty-one brachial plexus injury patients in the surgical database were eligible for this retrospective study. Patients were divided into two groups according to different surgical methods. Direct repair was performed in 27 patients, while acellular nerve allografts were used to bridge the gap between the contralateral C7 nerve root and upper trunk in 24 patients. The length of the harvested contralateral C7 nerve root was measured intraoperatively. Deltoid and biceps muscle strength, and degrees of shoulder abduction and elbow flexion were examined according to the British Medical Research Council scoring system; meaningful recovery was defined as M3–M5. Lengths of anterior and posterior divisions of the contralateral C7 in the direct repair group were 7.64 ± 0.69 mm and 7.55 ± 0.69 mm, respectively, and in the acellular nerve allografts group were 6.46 ± 0.58 mm and 6.43 ± 0.59 mm, respectively. After a minimum of 4-year follow-up, meaningful recoveries of deltoid and biceps muscles in the direct repair group were 88.89% and 85.19%, respectively, while they were 70.83% and 66.67% in the acellular nerve allografts group. Time to C5/C6 reinnervation was shorter in the direct repair group compared with the acellular nerve allografts group. Direct repair facilitated the restoration of shoulder abduction and elbow flexion. Thus, if direct coaptation is not possible, use of acellular nerve allografts is a suitable option. This study was approved by the Medical Ethical Committee of the First Affiliated Hospital of Sun Yat-sen University, China (Application ID: [2017] 290) on November 14, 2017.

Microneurosurgical treatment options in peripheral nerve compression syndromes after chemotherapy and radiation treatment

Chemotherapy-induced peripheral neuropathy and radiation-induced brachial plexopathy are extremely debilitating conditions which can occur after treatment of malignancy. Unfortunately, the diagnosis can be elusive, and this dilemma is further compounded by the lack of efficacious therapeutics to prevent the onset of neurotoxicity before initiating chemotherapy or radiation or to treat these sequelae after treatment. However, microsurgical nerve decompression can provide these patients with a viable option to treat this complication.

Decompression nerve surgery for diabetic neuropathy: a structured review of published clinical trials

AIM

To assess lower extremity decompression nerve surgery (DNS) to treat the consequences of diabetic distal symmetric peripheral neuropathy (DPN).

RESEARCH DESIGN AND METHODS

MEDLINE, PubMed, and related registries were searched through December 2017 to identify randomized, quasi-randomized or observational trials that evaluated the efficacy of lower extremity DNS on pain relief (primary outcome) or other secondary outcomes. Observational studies were included, given investigators' reluctance to use sham surgery controls. Outcome effect size was estimated, and a weighted average was calculated.

RESULTS

Eight of 23 studies evaluated pain relief, including a double-blind randomized controlled trial (with a sham surgery leg), an unblinded trial with a nonsurgical control leg, and 6 observational studies. All reported substantial pain relief post-DNS with average effect sizes between two and five. Unexpectedly, the double-blind trial showed improvement in the sham leg comparable to the DNS leg and exceeding the improvement observed in the nonsurgical leg in the unblinded study. Sensory testing showed generally favorable results supporting DNS, and nerve conduction velocities increased post-DNS relative to deterioration in controls. Ultrasound revealed fusiform nerve swelling near compression sites. Morphological results of DNS were generally favorable but inconsistent, whereas hemodynamic measures showed a positive effect on arterial parameters, as did transcutaneous oximetry (improved microcirculation). The incidence of initial and recurrent neuropathic diabetic foot ulcers appeared reduced post-DNS relative to the contralateral foot (borderline significant).

CONCLUSION

The data remain insufficient to recommend DNS for painful DPN, given conflicting and unexpectedly positive results involving sham surgery relative to unblinded controls. The generally supportive sensory and nerve conduction results are compromised by methodological issues, whereas more favorable results support DNS to prevent new or recurrent neuropathic foot ulcers. Future studies need to clarify subject selection vis-à-vis DPN vs superimposed compressed nerves, utilize appropriate validated instruments, and readdress use of sham surgical controls in light of recent results.

Optimization of Surgical Outcome in Lower Extremity Nerve Decompression Surgery

BACKGROUND

There is still debate regarding whether the surgical release of entrapped lower extremity nerves reduces complaints of associated neuropathy and results in gain of sensory function. The aim of this study was to investigate which factors are associated with a favorable surgical outcome, by follow-up of patients previously participating in a randomized controlled trial.

METHODS

The authors evaluated the 5-year follow-up of diabetic patients previously participating in the Lower Extremity Nerve Entrapment Study (LENS). Visual analogue pain scores, satisfaction, complaints, quality of life (i.e., 36-Question Short-Form Health Survey and EuroQol 5 Dimensions instrument), sensory function, and incident ulceration and amputation were assessed. Differences between patients who underwent unilateral versus bilateral decompressions were investigated.

RESULTS

Thirty-one of the original 42 LENS participants were measured, of which eight patients underwent additional decompression of the contralateral leg, after 12-month LENS follow-up. At 5 years, bilateral surgical patients (n = 8) had significantly lower pain scores and higher quality of life compared with unilateral surgical patients (n = 23), were younger, had a lower age when diagnosed with diabetes, and had a lower body mass index at baseline. Pain scores of the additional decompressed leg decreased in a manner similar to that of the initial decompressed leg during follow-up. Patients with severe preoperative sensory loss did worse; 41.2 percent of the LENS Follow-Up Study subjects underwent or considered undergoing contralateral surgery.

CONCLUSION

The authors' results suggest that the beneficial effects of lower extremity nerve decompression surgery are reserved for a select group of patients, of which preoperative nerve damage, age, duration of diabetes, and body mass index are important effect modifiers.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

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.

Decompressive Surgery for Diabetic Neuropathy: Waiting for Incontrovertible Proof

: Triple decompression surgery has been advocated as a treatment for diabetic peripheral neuropathy (DPN). A practice advisory published in 2006 by the American Academy of Neurology concluded that "this treatment alternative should be considered unproven." Since then, multiple cohort studies involving several thousands of patients and 1 nonblind, randomized, controlled trial have been published, suggesting that surgical treatment of DPN has become commonplace in many centers globally. The results of these observational studies suggest that decompressive surgery could result in a substantial reduction of pain and the restoration of sensation in patients with DPN. However, as these studies are all observational in design, the utility of surgery remains unproven. Furthermore, the selection of patients for surgery is based on the incorrect assumption that the presence of a Tinel sign at sites of potential entrapment indicates nerve compression. The utility of surgery could be determined through a randomized, double-blind, sham-controlled trial in which 1 leg is treated with surgical decompression and the other with sham surgery. This design would eliminate a large number of possible confounders and would therefore require only a small number of patients. Such a trial is currently being performed at the University of Texas. The true beneficiaries will be patients with DPN: either decompressive surgery will be established as an evidence-based treatment for millions of patients or they will be spared from potentially harmful surgery with no significant benefit.

ABBREVIATION

DPN, diabetic peripheral neuropathy.

Subclinical Peroneal Neuropathy: A Common, Unrecognized, and Preventable Finding Associated With a Recent History of Falling in Hospitalized Patients

PURPOSE

Identification of modifiable risk factors for falling is paramount in reducing the incidence and morbidity of falling. Peroneal neuropathy with an overt foot drop is a known risk factor for falling, but research into subclinical peroneal neuropathy (SCPN) resulting from compression at the fibular head is lacking. The purpose of our study was to determine the prevalence of SCPN in hospitalized patients and establish whether it is associated with a recent history of falling.

METHODS

We conducted a cross-sectional study of 100 medical inpatients at a large academic tertiary care hospital in St Louis, Missouri. General medical inpatients deemed at moderate to high risk for falling were enrolled in the summer of 2013. Patients were examined for findings that suggest peroneal neuropathy, fall risk, and a history of falling. Multivariate logistic regression was used to correlate SCPN with fall risk and a history of falls in the past year.

RESULTS

The mean patient age was 53 years (SD = 13 years), and 59 patients (59%) were female. Thirty-one patients had examination findings consistent with SCPN. After accounting for various confounding variables within a multivariate logistic regression model, patients with SCPN were 4.7 times (95% CI, 1.4-15.9) more likely to report having fallen 1 or more times in the past year.

CONCLUSIONS

Subclinical peroneal neuropathy is common in medical inpatients and is associated with a recent history of falling. Preventing or identifying SCPN in hospitalized patients provides an opportunity to modify activity and therapy, potentially reducing risk.

Pain Relief and Health-Related Quality-of-Life Improvement After Microsurgical Decompression of Entrapped Peripheral Nerves in Patients With Painful Diabetic Peripheral Neuropathy

Surgery had been shown to be effective for superimposed peripheral nerve entrapment syndrome in patients with diabetic peripheral neuropathy (DPN), with pain relief and sensation restored. Few studies, however, have reported the quality-of-life outcomes of surgery for the treatment of painful DPN (PDPN). The objective of the present study was to evaluate the effects of microsurgical decompression of multiple entrapped peripheral nerves on pain and health-related quality of life in patients with refractory PDPN of the lower limbs. Eleven patients with intractable PDPN of the lower limbs were recruited for the present study. All the patients underwent microsurgical decompression of the common peroneal nerve, deep peroneal nerve, and posterior tibial nerve. The pain intensity was assessed using the visual analog scale and health-related quality of life was measured using the short-form 36-item quality-of-life survey. Six (54.6%) patients experienced >50% pain relief (both daytime pain and nocturnal pain) at 2 weeks after the decompression procedure and 8 (72.7%) patients at 24 months postoperatively. Two (18.2%) patients experienced a >50% decrease in peak pain at the 2 weeks after the procedure and 8 (72.7%) patients at 24 months. Additionally, the scores from the short-form 36-item quality-of-life survey were significantly improved in the following 2 domains: bodily pain and general health at 2 weeks after the decompression procedure. Also, at 24 months postoperatively, 6 domains had significantly improved, including physical function, bodily pain, general health, social function, role emotional, and mental health. No significant side effects were recorded during the study. Microsurgical decompression of peripheral nerves is an effective and safe therapy for intractable PDPN with superimposed nerve compression.

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.

The Tinel sign has no diagnostic value for nerve entrapment or neuropathy in the legs

INTRODUCTION

The presence of a Tinel sign in leg nerves has been proposed as a criterion for decompressive surgery in polyneuropathy. We investigated the diagnostic yield of the Tinel sign for nerve entrapment and for distal symmetrical peripheral neuropathy (DSPN).

METHODS

We prospectively tested for the Tinel sign at 3 sites of possible nerve entrapment per leg in 91 patients. Entrapment was defined using nerve conduction data. We also investigated whether the number of sites at which the Tinel sign was present identified patients with DSPN.

RESULTS

Sensitivity of the Tinel sign for nerve entrapment was low (29%, 44%, and 17%) for the 3 sites, and specificity was moderate (86%, 75%, and 81%). In the subgroup with DSPN, sensitivity was extremely low (0%, 20%, and 8%), and specificity was moderate (91%, 79%, and 73%). The number of sites with a Tinel sign did not identify patients with DSPN.

CONCLUSION

The Tinel sign does not reliably indicate nerve entrapment or DSPN. Muscle Nerve 54: 25-30, 2016.

The effect of lower extremity nerve decompression on health-related quality of life and perception of pain in patients with painful diabetic polyneuropathy: a prospective randomized trial

AIMS

The aim of this study was to assess whether surgical decompression of nerves in the lower extremity in people with painful diabetic polyneuropathy would have an effect on health-related quality of life and to determine minimal clinically important differences in pain and quality of life scores.

METHODS

The design was a randomized controlled trial in which 42 participants with painful diabetic painful neuroapthy underwent unilateral decompression of nerves in their left or right leg, using the other leg as a control, with 12 months follow-up. Surgical decompression was performed at the tibial, superficial, deep and common peroneal nerves. Preoperatively, and at 6 and 12 months post operatively, a visual analogue scale for pain and the 36 item short-form health survey and EuroQual 5 Dimensions questionnaires were completed.

RESULTS

At 12 months follow-up, the visual analogue scale was significantly reduced, but decompression surgery did not significantly alter health-related quality of life scores. The minimal clinically important difference for visual analogue scale reduction was determined at 2.9 points decrease, a threshold reached by 42.5% of the study population.

CONCLUSIONS

Although decompression surgery does not influence health-related quality of life, it achieves a clinically relevant reduction of pain in ~42.5% of people with diabetic peripheral neuropathy. It can therefore be considered for patients who do not adequately respond to pain medication.

Evaluation of peripheral microcirculation improvement of foot after tarsal tunnel release in diabetic patients by transcutaneous oximetry

BACKGROUND

According to recent studies, peripheral nerve decompression in diabetic patients seems to not only improve nerve function, but also to increase microcirculation; thus decreasing the incidence of diabetic foot wounds and amputations. However, while the postoperative improvement of nerve function is demonstrated, the changes in peripheral microcirculation have not been demonstrated yet. The aim of this study is to assess the degree of microcirculation improvement of foot after the tarsal tunnel release in the diabetic patients by using transcutaneous oximetry.

PATIENTS AND METHODS

Twenty diabetic male patients aged between 43 and 72 years old (mean age 61.2 years old) suffering from diabetic peripheral neuropathy with superimposed nerve compression underwent transcutaneous oximetry (PtcO2) before and after tarsal tunnel release by placing an electrode on the skin at the level of the dorsum of the foot. Eight lower extremities presented diabetic foot wound preoperatively. Thirty-six lower extremities underwent surgical release of the tibialis posterior nerve only, whereas four lower extremities underwent the combined release of common peroneal nerve, anterior tibialis nerve, and posterior tibialis nerve.

RESULTS

Preoperative values of transcutaneous oximetry were below the critical threshold, that is, lower than 40 mmHg (29.1 ± 5.4 mmHg). PtcO2 values at one month after surgery (45.8 ± 6.4 mmHg) were significantly higher than the preoperative ones (P = 0.01).

CONCLUSIONS

The results of postoperative increase in PtcO2 values demonstrate that the release of the tarsal tunnel determines a relevant increase in microcirculation in the feet of diabetic patients.

Surgical decompression of painful diabetic peripheral neuropathy: the role of pain distribution

Objective

To investigate the effect of surgical decompression on painful diabetic peripheral neuropathy (DPN) patients and discuss the role which pain distribution and characterization play in the management of painful DPN as well as the underlying mechanism involved.

Methods

A total of 306 patients with painful diabetic lower-extremity neuropathy were treated with Dellon surgical nerve decompression in our department. Clinical evaluation including Visual analogue scale (VAS), Brief Pain Inventory Short Form for diabetic peripheral neuropathy (BPI-DPN) questionnaire, two-point discrimination (2-PD), nerve conduction velocity (NCV) and high-resolution ultrasonography (cross-sectional area, CSA) were performed in all cases preoperatively, and at 6 month intervals for 2 years post-decompression. The patients who underwent surgery were retrospectively assigned into two subgroups (focal and diffuse pain) according to the distribution of the diabetic neuropathic pain. The control group included 92 painful DPN patients without surgery.

Results

The levels of VAS, scores in BPI-DPN, 2-PD, NCV results and CSA were all improved in surgical group when compared to the control group (P<0.05). More improvement of VAS, scores in BPI-DPN and CSA was observed in focal pain group than that in diffuse group (P<0.05).

Conclusions

Efficacy of decompression of multiple lower-extremity peripheral nerves in patients with painful diabetic neuropathy was confirmed in this study. While both focal and diffuse group could benefit from surgical decompression, pain relief and morphological restoration could be better achieved in focal group.

Low long-term risk of foot ulcer recurrence after nerve decompression in a diabetes neuropathy cohort

BACKGROUND

Use of nerve decompression in diabetic sensorimotor polyneuropathy is a controversial treatment characterized as being of unknown scientific effectiveness owing to lack of level I scientific studies.

METHODS

Herein, long-term follow-up data have been assembled on 65 diabetic patients with 75 legs having previous neuropathic foot ulcer and subsequent operative decompression of the common peroneal and tibial nerve branches in the anatomical fibro-osseous tunnels.

RESULTS

The cohort's previously reported low recurrence risk of less than 5% annually at a mean of 2.49 years of follow-up has persisted for an additional 3 years, and cumulative risk is now 2.6% per patient-year. Nine of 75 operated legs (12%) have developed an ulcer in 4,218 months (351 patient-years) of follow-up. Of the 53 contralateral legs without decompression, 16 (30%) have ulcerated, of which three have undergone an amputation. Fifty-nine percent of patients are known to be alive with intact feet a mean of 60 months after decompression.

CONCLUSIONS

The prospective, objective, statistically significant finding of a large, long-term diminution of diabetic foot ulcer recurrence risk after operative nerve decompression compares very favorably with the historical literature and the contralateral legs of this cohort, which had no decompression. This finding invites prospective randomized controlled studies for validation testing and reconsideration of the frequency and contribution of unrecognized nerve entrapments in diabetic sensorimotor polyneuropathy and diabetic foot complications.

The foot and ankle examination

Most foot and ankle disorders can be diagnosed after a proper history and clinical examination and can be effectively managed in a primary care setting. It is important to assess the entirety of patient disorders that present as they can be multifactorial in cause. A broad differential should include disorders of bones, joints, muscles, neurovasculature, and surrounding soft tissue structures. Physical examination should be thorough and focused on inspection, palpation, range of motion, and appropriate special tests when applicable. This article highlights some of the salient features of the foot and ankle examination and diagnostic considerations.

Surgical treatment of superimposed, lower extremity, peripheral nerve entrapments with diabetic and idiopathic neuropathy

BACKGROUND

Although it is recognized that people with peripheral neuropathy have an increased prevalence of chronic nerve entrapment, controversy still exists over their management. The present report details the evaluation, surgical approach, and outcome of a large cohort of people with diabetic and with idiopathic neuropathy.

METHODS

A retrospective review of 158 consecutive patients, 96 with diabetic and 62 with idiopathic neuropathy, was done to analyze the results of neurolysis of multiple sites of chronic nerve compression in the lower extremity. Of these patients, 50 had a contralateral limb decompressed for a total of 208 limbs included in the study. Outcomes included visual analog scale (VAS) for pain in the 109 patients who had pain level greater than 8.0, measurement of the cutaneous pressure threshold for sensibility, self-reported change in pain medication usage, and self-reported change in balance.

RESULTS

With a minimum follow-up of 1 year, 88% of patients with preoperative numbness reported improvement in sensation (P < 0.001). Of the 84 patients with impaired balance, 81% reported improvement in balance. Of those whose VAS was greater than 8, 83% reported an improvement in VAS (P < 0.001). There was a concomitant reduction in pain medication usage. There was no difference in outcomes between patients with diabetic versus idiopathic neuropathy in response to nerve decompression.

CONCLUSIONS

Neurolysis of lower extremity chronic nerve compressions in patients with neuropathy and superimposed nerve compressions is an effective method for relieving pain, restoring sensation, and improving balance.

Therapeutic effect and risk factors for complications of excision in 76 patients with schwannoma

BACKGROUND

Benign schwannoma is the most common tumor of peripheral nerves. However, the clinical course of excision and risk factors associated with postoperative neurological deficits are not well known. We evaluated the incidence of preoperative symptoms, the incidence of postoperative neurological deficits, and the risk factors of neurological deficits.

METHODS

We retrospectively reviewed data of 76 patients with schwannomas treated at our institution. We reviewed the clinical characteristics, and postoperative results, and determined the possible risk factors influencing the development of complications.

RESULTS

Excision of schwannoma improved the Tinel-like signs in 47 of 51 patients and spontaneous pain in 14 of 15. Eleven of 17 patients with sensory deficits showed complete recovery, but six continued to show deficits with or without improvement. Motor deficits that were observed in four patients persisted in one. New neurological deficits developed in 21 patients and persisted until final follow-up in 8. Tinel-like signs was the risk factor of surgery-related neurological deficits (p = 0.009).

CONCLUSIONS

New deficits developed predominantly in patients with preoperative Tinel-like signs. Attention should be given to patients with the factor.

Interventional management of neuropathic pain: NeuPSIG recommendations

Neuropathic pain (NP) is often refractory to pharmacologic and noninterventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group, the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central poststroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: 1) epidural injections for herpes zoster; 2) steroid injections for radiculopathy; 3) SCS for FBSS; and 4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor radiofrequency lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials, long-term studies, and head-to-head comparisons among different interventional and noninterventional treatments.

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.

Neurosurgical prevention of ulceration and amputation by decompression of lower extremity peripheral nerves in diabetic neuropathy: update 2006

BACKGROUND

A triad of metabolic abnormalities are known that render the peripheral nerve in diabetes mellitus susceptible to chronic compression: conversion of glucose to sorbitol increases the intraneural water content, slowing of axoplasmic transport of proteins hinders structural repair, glycosylation of endoneurial collagen reduces perineurial gliding. In the early 1990s, Dellon et al demonstrated that removal of a site of anatomic narrowing of the tibial nerve in the rat model prevented neuropathic walking.

METHOD

Scientific literature related to this concept was reviewed. Through the end of 2006, there have been 15 peer-reviewed studies that used the inclusion criteria of (1) presence of symptomatic neuropathy, (2) positive Tinel sign over the tarsal tunnel demonstrating a site of compression, (3) no previous history of ulcer or amputation and (4) used the Dellon Triple Decompression technique (neurolysis of the peroneal nerve at the knee and the dorsum of the foot, and neurolysis of the tibial nerve in the four medial ankle tunnels).

FINDINGS

These studies demonstrated relief of pain in 88% and restoration of sensation in 79% of patients. One study demonstrated that the natural history of diabetic neuropathy can be changed by observing no ulcers/amputations in the operated leg of 50 diabetics followed for a mean of 4.5 years, while 12 ulcers and 3 amputations occurred in the non-operated contralateral limb (p < 0.001). Results of a multi-centered prospective study are available at NeuropathyRegistry.com, demonstrating a reduction in the prevalence of ulceration in 665 diabetics at 2.5 years from 15 to 0.6% in those diabetics without a previous history of ulceration and from 50 to 2.2% in 44 patients with a previous history of ulceration.

CONCLUSIONS

Decompression of superimposed nerve compressions in the patient with symptomatic neuropathy reliably relieves pain, restores sensation, and thereby prevents ulceration and amputation.

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.

Painful diabetic neuropathy

The podiatric physician often encounters complex painful neuropathies in daily practice. Diabetic neuropathy is one form of chronic neuropathic pain dealt with on a regular basis. The goal of this article is to review the pathophysiology, diagnosis, and treatment options of this complaint. Medical and surgical interventions are discussed, with a clinical emphasis on patient selection and prevention.

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.

Clinical Outcome of Peripheral Nerve Decompression in Diabetic and Nondiabetic Peripheral Neuropathy

Surgical decompression of peripheral nerves in patients with diabetes was reported to restore sensation and improve function. In this study, a retrospective review of 12 diabetic and 20 nondiabetic patients with lower-extremity peripheral neuropathy who underwent surgical decompression was performed. Clinical evaluation by Tinel test, muscle power examination, and 2-point discrimination were performed preoperatively, at 6 months, and between 9 and 15 months postdecompression. Clinical outcomes were classified into excellent, good, or fair based on improvement in symptoms and return of function. Thirty-two patients underwent 36 surgeries, in which 99 lower-extremity nerves were decompressed. There was a statistically significant improvement in muscle function (P < 0.001) and 2-point discrimination for the small toe (P = 0.008) and big toe (P = 0.038). At a mean of 7.7 months, 90% of patients showed significant improvement in pain and function. It is concluded that surgical decompression was associated with significant improvement in clinical outcome in patients with diabetic and idiopathic neuropathy with evidence of superimposed compression.

Relationship between peripheral nerve decompression and gain of pedal sensibility and balance in patients with peripheral neuropathy

This was an initial exploratory study to determine if decompression of the 4 medial ankle tunnels (neurolysis of the tibial, medial and lateral plantar, and calcaneal nerves) could lead to improved foot sensibility, increased proprioception and balance, and decreased falls in a population of patients with impaired lower extremity sensation. Fourteen patients with peripheral neuropathy were included in this study. Seventy-one percent of patients were females. Average age was 67 years. All patients were evaluated preoperatively and postoperatively to assess their lower extremity sensibility, as well as their ability to stand still, maintaining their balance with their eyes open and then closed, which is defined as "sway." Lower extremity sensibility was measured with the Pressure-Specified Sensory Device (PSSD), which evaluates 1- and 2-point discrimination for the pulp of the big toe and medial heel. The MatScan Measurement System measured each patient's sway. Neuropathy was the result of diabetes in 72% of patients, a combination of diabetes and hypothyroidism in 7%, chemotherapy in 7%, and idiopathic in 14%. Eight patients underwent peripheral nerve decompression on 1 lower extremity, whereas 6 patients underwent bilateral lower extremity peripheral nerve decompression. Mean toe and heel sensibility improved 9% and 7%, respectively, in the unilateral group, whereas the bilateral group experienced an improvement in mean toe and heel sensibility of 42% (P = 0.02) and 32%, respectively. Preoperative and postoperative sway comparison in the unilateral group revealed a reduction in sway with eyes open and eyes closed by 5% and 31%, respectively. Comparison of preoperative and postoperative sway in the bilateral group showed a reduction with eyes open and eyes closed by 23% and 145% (P = 0.05), respectively. This initial study suggests that there may be benefit from bilateral lower extremity peripheral nerve decompression in helping improve pedal sensibility and balance within the peripheral neuropathy patient population, although further investigation with a larger sample size is warranted to further evaluate these preliminary findings.

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.