Early detection of sensory nerve function impairment in leprosy under field conditions.

AIM: To assess the fine sensation of palms and soles in field conditions, to enable early detection of nerve function impairment before the loss of protective sensation, thus preventing the development of disability. METHODS: A cross-sectional descriptive study was conducted at seven tertiary referral hospitals located in different states in India. This study included all newly diagnosed patients affected by leprosy, who were registered during the period between March 2011 and April 2012. A detailed history was taken along with charting and voluntary muscle testing /sensory testing (VMT/ST) for the diagnosed patients. The sensation was measured using 0.2 gm Semmes-Weinstein filaments for palms and 4 gm for soles first, followed by 2 gm Semmes-Weinstein filaments for palms and 10 gm for soles. RESULTS: Among the 374 patients, 106 were identified with sensory nerve function impairment. Of the 106 patients, 84 were identified with absence of both fine and protective sensation and 22 patients had a loss of fine touch sensation with protective sensation intact. LIMITATION: This study was conducted only among patients who were newly diagnosed with leprosy. Hence, future longitudinal studies in a larger population will add more validity to the study. CONCLUSION: The patients who had loss of fine sensation would have been missed by the normal leprosy programme protocol which uses 2 gm and 10 gm filaments for testing sensory loss before initiating steroid therapy. Further research is needed to determine whether testing for fine sensation with 0.2 gm Semmes-Weinstein filaments for palms and 4 gm for soles can be introduced at all specialized leprosy centres to detect nerve function impairment at an earlier stage followed by steroid therapy.

Evaluation of altered patterns of tactile sensation in the diagnosis and monitoring of leprosy using the Semmes-Weinstein monofilaments.

BACKGROUND: Leprosy neuropathy is the most common peripheral neuropathy of infectious etiology worldwide; it is characterized as asymmetric and focal multiple mononeuropathy. Semmes-Weinstein monofilament (SWM) test is a simple method to assess sensory nerve function. METHODS AND FINDINGS: In this prospective cohort study, a dermatologist carried out hands and feet tactile sensation test with SWM in 107 multibacillary leprosy patients at diagnosis and in 76 patients at the end of treatment from 2016 to 2019. At diagnosis, 81/107 (75.7%) patients had some degree of functional disability, and 46 (43%) of them had altered SWM-test in the hands and 94 (87.9%) of them in the feet. After one year of multibacillary multidrug therapy, the disability decreasing to 44/76 patients (57.9%) and decreasing of the percentual of patients with altered SWM-test to 18% for the hands, and to 28.7% for the feet. At the end of treatment, the number of SMW-test points presented improvement in the hands of 22 (28.9%) patients, and in the feet of 47 (61.8%). In the hands, by SWM-test, only the radial nerve point demonstrated a significant asymmetry, while in the feet, the difference between the sum of altered SWM-test points showed significant asymmetry between both sides, highlighting the tibial nerve for the establishment of asymmetric leprosy neuropathy. In Spearman's correlation analysis, a positive correlation with statistical significance was observed between the number of hands and feet SWM altered points at diagnosis and the degree of disability at diagnosis (0.69) and at the end of the treatment (0.80). CONCLUSION: The patterns of hands and feet tactile sensation at diagnosis and their consequent modifications with the anti-leprosy drugs define the bacterial etiology of neuropathy, an important tool for the clinical diagnosis and follow up of the disease, highlighting the tibial nerve findings, the most affected nerve among leprosy patients by SWM-test, with significant asymmetry and focality impairments.

Relationship between Plantar Pressure and Sensory Disturbance in Patients with Hansen's Disease-Preliminary Research and Review of the Literature.

Orthoses and insoles are among the primary treatments and prevention methods of refractory plantar ulcers in patients with Hansen's disease. While dynamic plantar pressure and tactile sensory disturbance are the critical pathological factors, few studies have investigated whether a relationship exists between these two factors. In this study, dynamic pressure measured using F-scan system and tactile sensory threshold evaluated with monofilament testing were determined for 12 areas of 20 feet in patients with chronic Hansen's disease. The correlation between these two factors was calculated for each foot, for each clinical category of the foot (0-IV) and across all feet. A significant correlation was found between dynamic pressure and tactile sensation in Category II feet (n = 8, p = 0.016, r2 = 0.246, Spearman's rank test). In contrast, no significant correlation was detected for the entire foot or within the subgroups for the remainder of the clinical categories. However, the clinical manifestation of lesion areas showed high variability: (1) pressure concentrated, sensation lost; (2) margin of pressure concentration, sensation lost; (3) pressure concentrated, sensation severely disturbed but not lost; and (4) tip of the toe. These results may indicate that, even though there was a weak relationship between dynamic pressure and tactile sensation, it is important to assess both, in addition to the basics of orthotic treatment in patients with Hansen's disease presenting with refractory plantar ulceration.

Prevalence of leprous neuropathy determined by neurosensory testing in an endemic zone in Ecuador: Development of an algorithm to identify patients benefiting from early neurolysis.

The success of a microneurosurgical intervention in leprous neuropathy (LN) depends on the diagnosis of chronic compression before irreversible paralysis and digital loss occurs. In order to determine the effectiveness of a different approach for early identification of LN, neurosensory testing with the Pressure-Specified Sensory Device™ (PSSD), a validated and sensitive test, was performed in an endemic zone for leprosy. A cross-sectional study was conducted to analyze a patient sample meeting the World Health Organization (WHO) criteria for Hansen's disease. The prevalence of LN was based on the presence of ≥1 abnormal PSSD pressure threshold for a two-point static touch. A total of 312 upper and lower extremity nerves were evaluated in 39 patients. The PSSD found a 97.4% prevalence of LN. Tinel's sign was identified in 60% of these patients. An algorithm for early identification of patients with LN was proposed using PSSD testing based on the unilateral screening of the ulnar and deep peroneal nerves.

Analysis of catheter contact force during atrial fibrillation ablation using the robotic navigation system: results from a randomized study.

PURPOSE: Contact with cardiac tissue is an important determinant of lesion efficacy during atrial fibrillation (AF) ablation. The Sensei X™ robotic navigation system (RNS) (Hansen Medical, Mountain View, CA, USA) has been validated for contact force (CF) sensing expressed in grams (g). The Thermocool® SmartTouch™ catheter enables the measurement of catheter tip CF and direction inside the heart. We aimed to investigate the catheter CF with and without RNS during pulmonary vein isolation (PVI) procedures. METHODS: Eighty patients with symptomatic AF (56 males, age 63 ± 18) were enrolled in this study. Fifty-seven patients had paroxysmal AF and 23 early persistent AF. All procedures were performed with the Thermocool® SmartTouch™ ablation catheter. Forty patients were randomized to perform PVI with the Sensei X™ RNS (group 1), while in the other 40 patients (group 2), PVI was performed without the RNS. RESULTS: AF ablation was performed successfully in all patients without complications, while contact force was kept in the established 10-40 g range. A significantly higher CF was documented on the PVs in group 1 compared to group 2. The 1-year freedom from AF recurrence was higher in group 1 compared to group 2 (90 vs. 65 %, p = 0.04). Moreover, a significant reduction of fluoroscopy time was noted in the RNS group (13 ± 10 vs. 20 ± 10 min, respectively, p = 0.05). CONCLUSIONS: The Sensei X™ RNS permits a significantly higher CF during transcatheter AF ablation with a low rate of AF recurrence at clinical follow-up.

Comparison between Different Methods of Monofilament Test in Multibacillary Leprosy.

BACKGROUND: Leprosy or Hansen's disease predominantly affects skin and peripheral nerves; therefore, can cause visible deformities from sensory and motor impairment. Early detection of sensory deficit has been of great benefit in a vigorous preventive role. OBJECTIVE: To compare the result of sensory evaluation in multibacillary leprosy (AB) patients using Semmes-Weinstein monofilament (SWM) and conventional monofilament technique used in Thailand and to observe the course of neuritis detected during the study period MATERIAL AND METHOD: MB patients from Hansen's clinic at the Department of Dermatology, Siriraj Hospital, and Leprosy clinic at Raj Pracha Samasai Institute were evaluated for sensory impairment using monofilament test by both SWM and conventional technique for two consecutive follow-up visits. The patients'demographic data, clinical and laboratory findings, and course of disease were recorded RESULTS: Seventy MB patients were enrolled Two-third of the patients were male (71.4%) and a mean (SD) age was 43 (15.75) years with a range of 19 to 85-years-old. The results from SWM and conventional Thai technique were not statistically different for ulnar median, and posterior tibial nerve distribution excluding heel area (p = 1.00). Twenty-eight (40%) patients who mentioned of numbness at either palms or soles had impaired sensation detected by SWMtechnique (p = 0.014). CONCLUSION: Using SWMwith less tested points can minimize the time spent on sensory evaluation in MB patients; hence, we encourage the application of the present SWM technique to shorten the time in each follow-up visit and to improve the follow-up practice for better services of leprosy patients in Thailand.

Normal threshold values for a monofilament sensory test in sural and radial cutaneous nerves in Indian and Nepali volunteers.

The monofilament test (MFT) is a reliable method to assess sensory nerve function in leprosy and other neuropathies. Assessment of the radial cutaneous and sural nerves, in addition to nerves usually tested, can help improve diagnosis and monitoring of nerve function impairment (NFI). To enable the detection of impairments in leprosy patients, it is essential to know the monofilament threshold of these two nerves in normal subjects. The radial cutaneous, sural, ulnar, median and posterior tibial nerves of 245 volunteers were tested. All nerves were tested at three sites on both left and right sides. Normal monofilament thresholds were calculated per test-site and per nerve. We assessed 490 radial cutaneous and 482 sural nerves. The normal monofilament was 2 g (Filament Index Number (FIN) 4.31) for the radial cutaneous and 4 g (FIN 4.56) for the sural nerve, although heavy manual laborers demonstrated a threshold of 10 g (FIN 5.07) for the sural nerve. For median and ulnar nerves, the 200 mg (FIN 3.61) filament was confirmed as normal while the 4 g (FIN 4.56) filament was normal for the posterior tibial. Age and occupation have an effect on the mean touch sensitivity but do not affect the normal threshold for the radial cutaneous and sural nerves. The normal thresholds for the radial cutaneous and sural nerves are determined as the 2 g (FIN 4.31) and the 4 g (FIN 4.56) filaments, respectively. The addition of the radial cutaneous and sural nerve to sensory nerve assessment may improve the diagnosis of patients with impaired sensory nerve function.

A preliminary study of locognosia in people affected by leprosy.

Locognosia is the ability to localize a sensory stimulus on the body's surface and can be tested by graded filaments (Semmes-Weinstein monofilaments). This point localization of sensation (locognosia) wastested by SW filaments over four quadrants of the pulp of the fingers in ulnar/median and ulnar paralysis in 38 new patients affected by leprosy. The results were compared with standard testing of sensation at selected sites by Semmes Weinstein monofilament. Both pulp quadrant testing and standard site testing were done in leprosy patients and also in a group of controls. Sensation was tested in 73 hands in leprosy patients and 34 hands in controls. Results indicate a positive correlation between locognosia and standard SW filament testing. When locognosia and standard SW filament tests were compared, there was significant difference between the two tests to pick up abnormal sensation in leprosy patients both over the entire hand and over individual fingers. This preliminary study suggests that locognosia may be a useful tool to diagnose sensory impairment in leprosy. Further studies are required to corroborate this.

Avaliação sensitiva de hansenianos pelos monofilamentos Semmes-Weinstein em serviço terciário de fisioterapia / Effectiveness of Semmes-Weinstein monofilaments in leprosy neuropathy in physiotherapy tertiary sevice

OBJETIVOS: Identificar a frequência das alterações da sensibilidade de mãos e pés de hansenianos através dos monofilamentos Semmes-Weinstein no hospital terciário.MÉTODO: Trinta pacientes do setor de fisioterapia do Hospital da Clínicas da FMRP-USP foram avaliados clinico-epidemiologicamente e submetidos ao teste por monofilamentos de agosto a dezembro de 2004.RESULTADOS: A média de idade dos pacientes foi de 48,4 anos, sendo 80% do sexo masculino e 70% oriundos da região de Ribeirão Preto. Classificavam-se como multibacilares 70% dos pacientes e 80% apresentavam-se com Grau I de incapacidade. Quanto ao teste nos membros superiores, o nervo ulnar foi o mais acometido nos paucibacilares (78%) e nos multibacilares (83%). Nos membros inferiores, o ramo plantar medial do nervo tibial posterior encontrou-se acometido em todos os pacientes do grupo multibacilar. A sensação protetora estava ausente nas mãos em 26% no grupo pauci e 46% no multibacilar, e nos pés 44% no paucibacilar e 56% no multibacilar. O diagnóstico foi tardio em 37% dos pacientes, apresentando no mínimo dois nervos com perda da sensação protetora.CONCLUSÃO: Os resultados evidenciaram que o acompanhamento da neuropatia da hanseníase pelos monofilamentos S-W, mostrou-se capaz de identificar alterações da sensibilidade em múltiplos nervos das extremidades, tanto nos pacientes paucibacilares quanto multibacilares, tornando-se evidente a gravidade dos pacientes atendidos nos serviço de atenção terciária à saúde.

OBJECTIVES: To identify the frequency of changes in the sensibility of hands and feet from leprosy patients through the Semmes-Weinstein monofilament in tertiary hospital.METHOD: Thirty patients of the Physiotherapy Service of Hospital das Clínicas FMRP-USP were evaluated from August to December 2004. The patients were clinically and epidemiologically evaluated. Afterwards, monofilaments were tested.RESULTS: The mean age was 48.4 years, 80% male and 70% came from the Ribeirão Preto region. Seventy percent of the patients were classified as multibacilary and 80% presented grade 1 of incapacity. Concerning to Semmes-Weinstein test on the upper limbs, the ulnar was the most impaired nerve on the paucibacillary patients (78%) and on the multibacillary (83%). On the lower limbs, the plantar medial branch from the tibial posterior nerve had been impaired in all patients. The protective sensation was absent on the hands in 26% on the paucibacillary group and 46% on the multibacillary, and on the feet in 44% on the paucibacillary and 56% on the multibacillary. Thirty seven percent of the patients have received late diagnosis, showing at least two nerves without protective sensation.CONCLUSIONS: The results showed the reliable use of Semmes-Weinstein monofilaments during the follow up of leprosy patients. This tool was able to identify sensitive changes in multiple nerves of the extremities, for paucibacilary and multibacilary patients, what clearly shows the severity of incoming patients in health tertiary care service.

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.

Comparative study of the cutaneous sensation of leprosy-suspected lesions using Semmes-Weinstein monofilaments and quantitative thermal testing.

The objective of the present study was to compare the warm cold perception thresholds (WPT), cold perception thresholds (CPT) and the warm and cold perception interval (WCPI) determined in our previous study with the touch-pressure thresholds, in leprosy-suspected skin lesions ('patch'). Thermal testing was conducted using a thermal sensory analyser TSA-2001 (Medoc Ltd., Israel) and the method of levels. The touch-pressure thresholds were measured using Semmes-Weinstein monofilament (SWM) of 0-05 g, 0.2 g, 2 g, 4 g, 10 g and 300 g. A cross-sectional study of 112 patients presenting with leprosy-suspected skin lesions, with no clinical evidence of peripheral nerve damage, was conducted. Leprosy diagnoses were based on clinical dermato-neurological examinations. One-hundred-and-eight subjects (45 males, 63 females; average age 37.7 years) completed the tests: 82 were positively diagnosed with leprosy and 26 with diseases of different aetiologies. The SWM test showed a sensitivity of 81.7% and a specificity of 96.1%, while the warm and cold perception thresholds presented sensitivity of 90.2% and 92-2%, respectively (both with 100% specificity). In leprosy patients, lesions that exhibited pressure thresholds of 0.05 g typically showed significantly different WPT, CPT and WCPI values when compared with skin lesions of different aetiologies. Within the leprosy group, the mean values of WPT, CPT and WCPI increased according to the increase in touch-pressure thresholds. Some of the patients exhibiting leprosy lesions with touch-pressure thresholds of 0-05 and 0-2 g presented normal WPT or CPT values. However, all patients with SWM equal or above 2.0 g presented altered WPT and CPT. All patients with leprosy, including those that exhibited pressure thresholds of 0.05 g, presented altered WCPI in the skin lesions. Despite a higher sensitivity to thermal tests, the SWM has adequate validity as a screening tool in the diagnosis of cutaneous forms of leprosy and in the selection of patients who should be submitted to a more detailed examination.

Is there a relationship between light touch-pressure sensation and functional hand ability?

PURPOSE: To investigate and compare the level of light touch-pressure sensation as tested via the Semmes Weinstein monofilament (SWM) test with the level of functional hand ability. METHODS: Twenty-seven persons with isolated sensory deficit due to leprosy and 31 healthy controls were tested in the Occupational Therapy department of a hospital for patients with Hansen's disease. Palmar light touch thresholds were determined by SMW testing. Functional hand ability was tested via the Jebsen-Taylor Hand Function Test (JTHFT) and the Functional Dexterity Test (FDT). All participants were measured by manual muscle testing (MMT) to exclude any motor impairment. Data analysis compared sensory thresholds and level of functional hand ability between the two groups and examined the relationship between the variables. RESULTS: In the group with sensory deficit, the sensory thresholds were significantly higher than in the control group. Significant correlations were found between the sensory thresholds measured by the SWM test and the FDT and JTHFT scores, with higher correlations found for tasks entailing manipulation of small objects. CONCLUSIONS: The findings support the existence of a relationship between sensory light touch thresholds tested by the Semmes Weinstein monofilaments (SWMs) and hand function. However, the SWM test alone is not sufficient as an indicator of hand function and must therefore be supplemented with other hand function tests.

Detection of neuropathy due to Mycobacterium leprae using noninvasive neurosensory testing of susceptible peripheral nerves.

The prevalence of disability in patients with Hansen disease is related to peripheral nerve dysfunction. This dysfunction, which is due to chronic nerve compression, is the result of invasion of the peripheral nerve by Mycobacteria leprae. This suggests that early identification of M. leprae would be aided by detection of early stages of peripheral nerve compression. Traditional evaluation of peripheral nerve function with monofilaments, electrodiagnostic testing, or by observing motor palsy or digital ulcers unfortunately identifies only late sequelae of peripheral nerve dysfunction. The cutaneous pressure threshold required to identify 1 from 2 static-touch stimuli was obtained with the Pressure-Specified Sensory Device in upper and lower extremities of 51 patients who completed multidrug therapy for Hansen disease. Abnormal peripheral nerve function was identified in each patient and in each of the 120 bilateral nerves that were evaluated. The degree of nerve dysfunction included the range from early to late stages of nerve compression, suggesting that this method of neurosensory testing offers the possibility for early detection of peripheral nerve problems in Hansen disease.

Near-nerve potential in lepromatous leprosy.

In leprosy, sensory action potentials (SAPs) may be normal in spite of clinical sensory loss. This may result from the early involvement of small nerve fibers, which have potentials that are not detected in routine studies. To evaluate this possibility, we used a near-nerve recording technique that records potentials from nerve fibers as small as 4-6 microm in diameter. We hypothesized that this technique might increase the sensitivity of nerve conduction studies in detecting leprosy neuropathy. We found the technique to be useful for recording conduction abnormalities in recently diagnosed patients, including those with preserved sensation, suggesting that axonal loss may be the underlying mechanism. Contrary to our hypothesis, however, recording the late SAP components did not improve the sensitivity of nerve conduction studies. We suggest that the late components having normal conduction velocities may be generated by either regenerating or remyelinating abnormal fibers, which have an electrophysiological behavior similar to that of normal 4-6-microm-diameter fibers.

Sensory testing in leprosy: comparison of ballpoint pen and monofilaments.

The 10 g monofilament has been replaced by the ballpoint pen in routine sensory testing of nerves in leprosy control in Ethiopia. Results of sensory testing between the ballpoint pen and different monofilaments on hands and feet were compared. Ballpoint pen underdiagnosis of loss of sensation was defined to occur when the pen was felt and the monofilament was not. Differences were evaluated both for individual test points (test point level) and for the test points of extremities collectively (extremity level). An extremity (either a hand or a foot) was defined as having sensory nerve function impairment (SNFI) if a supplying nerve had SNFI, which was the case when sensation was absent in two or more test points in the area supplied by that nerve. At test point level, the percentages with ballpoint pen underdiagnosis relative to the 2, 10, 20 and 50 g monofilaments were 40, 21, 9 and 7%, respectively, in the hands, and 47, 30, 15 and 7% in the feet. Ballpoint pen underdiagnosis percentages of SNFI at extremity level were 32, 18, 8 and 9% in the hands, and 37, 26, 14 and 6% in the feet. The risk of ballpoint pen underdiagnosis appears to be higher in extremities without visible damage. In conclusion, substantial levels of underdiagnosis of sensory loss with the ballpoint pen were observed. However, the consequences for the prognosis of treatment with corticosteroids in patients with the more subtle sensation loss noted here need to be established. Development and testing of guidelines is a prerequisite for the use of the ballpoint pen.

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.