Saphenous nerve transfer: A new approach to restore sensation of the sole.

BACKGROUND: Loss of protective sensation of the sole may lead to repeated trauma, chronic nonhealing ulcers, and even amputation. Saphenous nerve (SN) to posterior tibial nerve (PTN) transfer can restore sensation of the sole. METHOD: This study was conducted in a tertiary referral center in Central India. Twenty-one patients (32 feet) diagnosed with loss of sensation of the sole were included in this study. Causes of loss of sensation were Hansen's disease (n = 18), complex sciatic nerve injury (n = 1), lumbosacral spinal tumor (n = 1), and lumbosacral meningomyelocele (n = 1). Seventeen feet (14 patients) had ulcers on the sole. Preoperative and postoperative sensory tests performed on the sole included tests for touch, pain, temperature, pressure, vibration, and two-point discrimination. Results were classified as per the British Medical Research Council (MRC) scoring system. RESULTS: Seventeen patients (26 feet) were available for follow-up at 6 months after surgery. All patients had improvement in sensory parameters. Ulcers completely healed in 13 feet and reduced in size in four feet. MRC score improved from S0 in 22 feet and S1 in 10 feet to S3 + in 20 feet, S3 in four feet, and S2 in two feet. CONCLUSIONS: Sensory neurotization with SN transfer to PTN can restore protective sensation to the sole and help in the healing of ulcers.

Tactile threshold detection in leprosy patients with an electronic algometer.

OBJECTIVE: To propose an electronic method for sensitivity evaluation in leprosy and to compare it to the Semmes-Weinstein monofilaments. METHODS: Thirty patients attending the Dermatology outpatient clinic of HCFMRP-USP were consecutively evaluated by both the electronic aesthesiometer and Semmes-Weinstein monofilaments on hand and foot test points. The intraclass correlation coefficient (ICC) was calculated to determine the variability of the electronic measures and the Kappa coefficient was calculated to determine the agreement between methods according to their categories (altered and non-altered tactile sensitivity). RESULTS: The ICC was approximately 1, demonstrating repeatability. The Kappa coefficient showed more than 75 and 63% agreement on the hand and foot points, respectively. The mean agreement between the 2 methods for the 7 points of the right and left hand was 77.14 and 75.71%, respectively. The mean agreement for all 10 points was 74.33 and 63.66% on the right and left foot, respectively. In cases of disagreement the detection of altered tactile sensitivity by the electronic esthesiometer on the right and left foot was 90.91 and 84.25%, respectively, with no detection by the monofilaments. CONCLUSION: The results suggest that the electronic esthesiometer is a reliable and easy application, capable of evaluating alterations of tactile sensitivity in leprosy patients.

Dorsal sensory impairment in hands and feet of people affected by Hansen's disease in Israel.

INTRODUCTION: Sensory testing in people affected by Hansen's disease is usually performed on palms and soles only. In Israel, both palmar/plantar and dorsal aspects of limbs are routinely tested. OBJECTIVES: The aim of this study was to describe the magnitude of dorsal sensory impairment (SI) in limbs and compare the frequency of SI on palms and soles with that on the dorsum of hands and feet. DESIGN: In a cross-sectional study, limbs of 140 patients registered at The Israel Hansen's Disease Centre during the years 1999-2003 were tested for their sensory status. Both palmar/plantar and dorsal aspects were tested using Semmes-Weinstein monofilaments. SI was defined as not feeling stimuli applied with the 2 g monofilament. RESULTS: SI was detected on the dorsum in 43% of sites on hands and only in 27% on palms. 64% of sites on dorsum of feet had SI compared to 53% on the soles. SI was detected in up to 18% in hands with no palmar SI, and in 6% of feet with no plantar SI. Furthermore, SI on palms and soles was found to be accompanied by dorsal SI in all hands and in 97% of feet. CONCLUSION: SI on dorsum of limbs occurs more frequently than SI on palms and soles. Therefore sensory testing should also consider inclusion of the dorsal aspect of hands and feet.

Histopathological and clinical findings in leprosy patients with chronic neuropathic pain: a study from Hyderabad, India.

BACKGROUND: Chronic neuropathic pain in leprosy patients after completion of multi-drug therapy (MDT) is an under-researched problem. The reason why some leprosy patients develop it is unknown. In this study we evaluated the role of ongoing inflammation and small-fibre neuropathy as possible contributing factors for neuropathic pain. METHODS: We assessed chronic neuropathic pain in 17 leprosy patients who had completed MDT and were attending a referral clinic in Hyderabad, India. All patients had a clinical assessment, intraepidermal nerve (IENF) assessment and quantitative sensory testing (QST), which included the testing of tactile and pinprick sensations using Semmes-Weinstein monofilaments and weighted needles method. Nine patients had a sural nerve biopsy (SNB). RESULTS: Thirteen patients had a glove and stocking pattern of neuropathy. All nerve biopsies showed inflammation with intraneural inflammation and perineural thickening, and intraneural acid fast bacilli were observed in five biopsies. IENF analysis of the skin biopsy specimens in 16/17 patients showed a statistically significant reduction in IENF density (P < 0.001, Mann Whitney test) compared to control skin biopsies. Complete depletion of intraepidermal nerves was observed in six patients. QST also showed marked abnormalities. In 11 patients total sensory loss for all modalities was found, and in the other six patients the sensory function was seriously impaired. DISCUSSION: There is evidence of ongoing intraneural inflammation in leprosy patients who have completed MDT. This may explain the occurrence of chronic neuropathic pain. Using IENF density measurement we have found significant small-fibre neuropathy in leprosy patients and the use of this tool could be expanded.

The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients

Plantar intrinsic foot muscles provide structure to the foot during walking and thus regulate mechanical foot sole stresses. When paralyzed, for instance in leprosy patients with neuropathy of the distal part of the tibial nerve, there is a high prevalence of plantar ulceration and deformities, especially when muscle weakness goes together with loss of foot sole sensibility. These patients should get immediate care involving education, special footwear and reconstructive surgery before further foot impairment and deformity becomes manifest. Thus far, in leprosy patients little attention is paid to screening of plantar intrinsic muscles activity. This can be done with a new simple and non-invasive method, the Paper Grip Test (PGT). There are two variants for detecting intrinsic muscle weakness of the foot, PGT1 for the great toe and PGT2 for the combined lesser toes. In this study, 517 leprosy patients and 170 healthy volunteers were investigated with the PGT. Sensibility of the foot sole was tested by means of a 10 gram monofilament. Specificity to the PGT1 is found to be about 95.3% which is considered good for physical diagnostic tests. PGT2 is less specific than PGT1. Individual muscle power and understanding of the patient seems to influence the outcome of the test to a certain extent. Sensitivity can only be calculated when the diagnosis is confirmed by electromyography. Especially patients with anesthetic feet, females, older patients and patients with PN-, BB- or LL-types of leprosy appeared to have a higher prevalence of intrinsic foot muscle weakness. All results were analyzed by means of the bivariate Pearson correlation-analysis and proved to be statistically significant (p = < 0.05). It is concluded that the PGT1, more than the PGT2, is a useful screening test on the function of plantar intrinsic foot muscles in leprosy patients in hospitals and during fieldwork in developing countries.

Leprosy affects the tibial nerves diffusely from the middle of the thigh to the sole of the foot, including skip lesions.

This study investigated where leprosy affects the posterior tibial nerve and whether neurolysis is beneficial. Nine patients with bilateral posterior tibial leprous neuropathy with no sensorimotor recovery were studied. Preoperative sensory-muscle and nerve conduction velocity testing revealed the tarsal tunnel to be the site of a severe lesion in all cases. During surgery, the most proximal site of the nerve lesion was detected by electrically stimulating the spinal roots from the second lumbar nerve to the fourth sacral nerve, evoking efferent mixed nerve compound action potentials that were recorded from the exposed tibial nerve. In all patients, the nerve compound action potentials became normal only proximal to the sciatic nerve bifurcation. Epineuriotomy within these seemingly unaffected segments revealed fibrosis of the interfascicular epineurium. Interfascicular neurolysis was performed on all affected segments. A 2-year follow-up showed an increase in girth of the proximal calf musculature in six of eight patients (the ninth patient had no recordable nerve conduction velocity). It was concluded that (1) leprosy affects the tibial nerves in a scattered way from the sciatic nerve main trunk distally to the exit of the tarsal tunnel; and (2) interfascicular, microsurgical neurolysis is beneficial provided that it is performed on all affected nerve segments.

The age-dependent deterioration in light touch sensation on the plantar aspect of the foot in a rural community in India: implications when screening for sensory impairment.

Regular testing for impaired sensation is important in the management of diseases that can cause progressive nerve damage, such as leprosy. It has been shown that light touch sensibility decreases with age in the hands of healthy individuals, but little research has been undertaken to assess possible changes in the feet in developing countries. This information is needed to allow an appropriate level of sensation to be chosen when screening for nerve damage in the foot. To clarify this, a cross-sectional study on male adults was carried out in the rural town of Salur, Andhra Pradesh, India. A range of Semmes-Weinstein monofilaments were employed at 12 locations on the foot to determine sensation to light touch stimuli in individuals from each decade of adult life. It was found that in this population, sensibility threshold in the foot increases with age and this was noted in both soft and callous skin. This shows the increase was due to neurological factors, not merely due to an increase in callous deposition with advancing age. In the majority of individuals in their fifties and sixties, the callous skin at the forefoot and heel was unable to detect the 5.07 monofilament (equivalent to 8-12 g), previously recommended as a method to screen for plantar neuropathy. All areas of all feet were able to detect the 5.46 filament (approximately 30 g). The size of this study (54 individuals) prevents the determination of definitive normal ranges for each decade of life in this population. However, it does demonstrate the degree to which sensation deteriorates with age and could be used as an approximate guide when interpreting the results of sensory testing in similar rural areas of the developing world.

Techniques for covering soft tissue defects resulting from plantar ulcers in leprosy: Part III. Use of plantar skin or musculocutaneous flaps and anterior leg flap.

Anatomical studies suggest that five types of plantar flaps namely, the lateral and medial plantar flaps, the Abductor hallucis-, the Flexor digitorum brevis-, and the Abductor digiti minimi-myocutaneous flaps, can be incised from the central section of the sole. The advantages of a plantar flap are recognizable neurovascular bundles of the sole, wide calibre of constantly located blood vessels, identical histological structure of the donor and the recipient sites, hidden donor site and absence of functional deficit. We have used the plantar flaps in seven cases. There has been no recurrence of ulceration in any of them during the follow-up period of 12 to 108 months. An anterior leg flap based on the cutaneous branches of the anterior tibial artery, with firmly anchored vessels, a long pedicle with wide vessels may be used not only as a free flap graft for reconstruction of moderate degree distant defects but also as a retrograde island flap graft for the reconstruction of adjacent tissue defect. We have used the retrograde island flap graft based on the anterior tibial artery in five cases of plantar ulceration with satisfactory results. There was no recurrence of ulceration during the follow-up period of 48 to 72 months.

Use of the Semmes-Weinstein 5.07/10 gram monofilament: the long and the short of it.

The Semmes-Weinstein monofilament has been developed for the detection of patients at risk of neuropathic ulceration. In this study we evaluated how the physical characteristics of the monofilaments can impact on their performance. Commercially purchased monofilaments from the Hansen's Disease Center (HDC) and a batch produced 'in-house' (RPAH) were calibrated using a Mettler Balance. To assess the effects of varying lengths on buckling force, the monofilaments were tested repeatedly while the length of the filament was reduced stepwise from 4.1 to 3.1 cm. The correct length of the monofilament to generate a buckling force of 10 g was also determined theoretically by applying the Euler's Buckling Equation. Results showed neither batch of monofilaments buckled at a strength of 10 g (HDC 6.8 g, CI 5.7-7.9, and RPAH 7.2 g, CI 7.1-7.3). In addition HDC showed a wide interfilament variation range, 4.1-10.3 g with CV 29% versus corresponding figures of range 7.1-7.9 g, CV 4.9% for the RPAH monofilaments. As predicted by Euler's Buckling Theory, buckling force can be increased by reducing the length of the filament. These results demonstrate that the physical characteristics of the monofilament are important determinants of buckling force and are not necessarily uniform in commercial filaments. The clinical relevance of variance in buckling force remains to be determined.

Tibialis posterior transfer for the correction of foot drop in leprosy. Long-term outcome.

A comparison was made of the results produced by the circumtibial and interosseous routes of transfer of tibialis posterior for the correction of foot drop due to leprosy neuritis. The findings in 69 feet, of which 63 also had elongation of tendo Achillis, showed that the interosseous route gave a much lower incidence of recurrent inversion deformity of the foot. The results, in terms of improvement in gait and prevention of trophic changes, were satisfactory.

A preliminary objective evaluation of leprosy footwear using in-shoe pressure measurement.

The primary function of leprosy shoes, insoles and podiatric orthoses is to provide an underfoot environment capable of distributing the inevitable vertical forces, so reducing areas of peak pressure and ideally the period through which they are applied. Many patients with Hansen's disease have both skeletal deformity and anesthetised feet and the presence of high plantar pressures is the key reason for foot ulceration. This objective investigation using in-shoe dynamic pressure measurements showed that the addition of a shank to control insole rigidity reduced the overall peak pressures under the foot. When a deep canvas shoe was used to test single- and double-thickness insoles of two different types of material it was found in each case that the double-thickness mode was advantageous overall. Microcellular rubber insoles in two types of leprosy shoe were replaced by the polymer Poron. The Poron proved to be superior to both microcellular rubbers. The peak pressure and pressure-time integral should be considered as complimentary variables when determining the efficacy of footwear.