Reliability of Semmes Weinstein monofilament and ballpoint sensory testing, and voluntary muscle testing in Bangladesh

Semmes-Weinstein monofilament: A tool to quantify skin sensation in macular lesions for leprosy diagnosis

INTRODUCTION

Hypochromatic macules with altered sensitivity are the first manifestations of skin leprosy. Validation of this sensory loss assists in the confirmation of the clinical diagnosis.

AIMS

The aim of the study was to quantify the loss of sensation in leprosy lesions using the Semmes-Weinstein monofilament to strengthen the clinical diagnosis mainly of macular forms.

METHODS

Seventy-four hypochromatic macules in the macular leprosy subgroup, 27 typical borderline leprosy subgroup lesions and 49 macules of other macular dermatoses (non-leprosy group) were evaluated using the 0.05 g force Semmes-Weinstein monofilament to quantify the alteration of sensitivity within and outside of the lesions. The esthesiometric change index was established as the total number of points with altered sensation divided by the total number of tested points within the lesions to calculate the internal esthesiometric change index and outside the lesions to calculate the peripheral esthesiometric change index; these indexes were calculated for all groups. The difference (Δ) between the esthesiometric change indices of the lesional area and the adjacent skin was calculated for the leprosy and nonleprosy groups.

RESULTS

The percentage of points with touch sensitivity alterations within the macular and typical borderline leprosy lesions was higher in leprosy than in the non-leprosy group. The borderline and macular leprosy presented higher esthesiometric change index within injured areas than outside injured areas or in the nonleprosy group (P < 0.005). When internal esthesiometric change index values in the macular and borderline leprosy groups were higher than 0.53 and 0.5, respectively, the receiver operating characteristic curve showed 98% sensitivity and approximately 99% specificity for both groups (P < 0.0001). Regarding the difference between indices, borderline and macular leprosy had values that were higher and closer to one than in the nonleprosy group (P < 0.0001), with 100% sensitivity and 96.5% specificity for leprosy diagnosis when ΔLG was higher than 0.34. A limitation was the inability to perform a double-blind study.

CONCLUSION

Semmes-Weinstein esthesiometry is a simple, useful and low-cost tool to quantify the focal alteration of cutaneous sensitivity to improve clinical leprosy diagnosis, especially for macular lesions.

Referent control of anticipatory grip force during reaching in stroke: an experimental and modeling study

To evaluate normal and impaired control of anticipatory grip force (GF) modulation, we compared GF production during horizontal arm movements in healthy and post-stroke subjects, and, based on a physiologically feasible dynamic model, determined referent control variables underlying the GF-arm motion coordination in each group. 63% of 13 healthy and 48% of 13 stroke subjects produced low sustained initial force (< 10 N) and increased GF prior to arm movement. Movement-related GF increases were higher during fast compared to self-paced arm extension movements only in the healthy group. Differences in the patterns of anticipatory GF increases before the arm movement onset between groups occurred during fast extension arm movement only. In the stroke group, longer delays between the onset of GF change and elbow motion were related to clinical upper limb deficits. Simulations showed that GFs could emerge from the difference between the actual and the referent hand aperture (R_a) specified by the CNS. Similarly, arm movement could result from changes in the referent elbow position (R_e) and could be affected by the co-activation (C) command. A subgroup of stroke subjects, who increased GF before arm movement, could specify different patterns of the referent variables while reproducing the healthy typical pattern of GF-arm coordination. Stroke subjects, who increased GF after arm movement onset, also used different referent strategies than controls. Thus, altered anticipatory GF behavior in stroke subjects may be explained by deficits in referent control.

Corticosteroids for treating nerve damage in leprosy

BACKGROUND

Leprosy causes nerve damage that can result in nerve function impairment and disability. Corticosteroids are commonly used for treating nerve damage, although their long-term effect is uncertain. This is an update of a review first published in 2007, and previously updated in 2009 and 2011.

OBJECTIVES

To assess the effects of corticosteroids on nerve damage in leprosy.

SEARCH METHODS

On 16 June 2015, we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL Plus, and LILACS. We also checked clinical trials registers and contacted trial authors.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of corticosteroids for nerve damage in leprosy. The comparators were no treatment, placebo treatment, or a different corticosteroid regimen.

DATA COLLECTION AND ANALYSIS

The primary outcome was improvement in nerve function after one year. Secondary outcomes were change in nerve pain, limitations in activities of daily living, limitations in participation, and adverse events. Two review authors independently extracted data and assessed trial quality. When data were lacking, we contacted trial authors for additional information.

MAIN RESULTS

We included five RCTs involving 576 people. The trials were largely at low risk of bias, but we considered the quality of the evidence from these trials as moderate to low, largely due to imprecision from small sample sizes. Two out of the five trials reported on improvement in nerve function at one year. These two trials compared prednisolone with placebo. One trial, with 84 participants, treated mild sensory impairment of less than six months' duration, and the other, with 95 participants, treated nerve function impairment of 6 to 24 months' duration. There was no significant difference in nerve function improvement after 12 months between people treated with prednisolone and those treated with placebo. Adverse events were not reported significantly more often with corticosteroids than with placebo. The other three trials did not report on the primary outcome measure. One (334 participants) compared three corticosteroid regimens for severe type 1 reactions. No serious side effects of steroids were reported in any participant during the follow-up period. Another trial (21 participants) compared low-dose prednisone with high-dose prednisone for ulnar neuropathy. Two participants on the higher dose of prednisone reported adverse effects. The last (42 participants) compared intravenous methylprednisolone and oral prednisolone with intravenous normal saline and oral prednisolone. The trial found no significant differences between the groups in the occurrence of adverse events.

AUTHORS' CONCLUSIONS

Corticosteroids are used for treating acute nerve damage in leprosy, but moderate-quality evidence from two RCTs treating either longstanding or mild nerve function impairment did not show corticosteroids to have a superior effect to placebo on nerve function improvement. A third trial showed significant benefit from a five-month steroid regimen over a three-month regimen in terms of response to treatment (need for additional corticosteroids). Further RCTs are needed to establish optimal corticosteroid regimens and to examine the efficacy and safety of adjuvant or new therapies for treating nerve damage in leprosy. Future trials should address non-clinical aspects, such as costs and impact on quality of life, which are highly relevant indicators for both policymakers and participants.

Effect of duration and amplitude of direct current when lidocaine is delivered by iontophoresis

Dosage for the galvanic stimulation for iontophoresis varies. Clinicians manipulate the duration or the amplitude of the current, but it is not known which is more effective. We compared the anesthetic effect of lidocaine HCL (2%) by manipulating the current parameters on 21 healthy volunteers (age: 21.2 ± 4.2, height 170.7 ± 10.2 cm, mass 82.1 ± 19.2 kg). Three conditions were administered in a random order using a Phoresor II^® with 2 mL, 2% lidocaine HCL in an iontophoresis electrode. (1) HASD (40 mA_*min): High amplitude (4 mA), short duration (10 min); (2) LALD (40 mA.min): Low amplitude (2 mA), long duration (20 min); (3) Sham condition (0 mA, 20 min). Semmes-Weinstein monofilament (SWM) scores were taken pre and post intervention to measure sensation changes. Two-way ANOVA with repeated measures was used to compare sensation. Both iontophoresis treatments: LALD (4.2 ± 0.32 mm) and HASD (4.2 ± 0.52 mm) significantly increased SWM scores, indicating an increase in anesthesia, compared to the sham condition (3.6 ± 0.06 mm) p < 0.05. Neither LALD nor HASD was more effective and there was no difference in anesthesia with the sham. Lidocaine delivered via iontophoresis reduces cutaneous sensation. However, there was no benefit in either a HASD or LALD treatment.

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.

Preventing nerve function impairment in leprosy: validation and updating of a prediction rule

Background

To validate and update a prediction rule for estimating the risk of leprosy-related nerve function impairment (NFI).

Methodology/Principal Findings

Prospective cohort using routinely collected data, in which we determined the discriminative ability of a previously published rule and an updated rule with a concordance statistic (c). Additional risk factors were analyzed with a Cox proportional hazards regression model. The population consisted of 1,037 leprosy patients newly diagnosed between 2002 and 2003 in the health care facilities of the Rural Health Program in Nilphamari and Rangpur districts in northwest Bangladesh. The primary outcome was the time until the start of treatment. An NFI event was defined as the decision to treat NFI with corticosteroids after diagnosis. NFI occurred in 115 patients (13%; 95% confidence interval 11%–16%). The original prediction rule had adequate discriminative ability (c = 0.79), but could be improved by substituting one predicting variable: ‘long-standing nerve function impairment at diagnosis’ by ‘anti-PGL-I antibodies’. The adjusted prediction rule was slightly better (c = 0.81) and identified more patients with NFI (80%) than the original prediction rule (72%).

Conclusions/Significance

NFI can well be predicted by using the risk variables ‘leprosy classification’ and ‘anti-PGL-I antibodies’. The use of these two variables that do not include NFI offer the possibility of predicting NFI, even before it occurs for the first time. Surveillance beyond the treatment period can be targeted to those most likely to benefit from preventing permanent disabilities.

Leprosy is caused by a bacterium that attacks the peripheral nerves. This may cause nerve function impairment (NFI), resulting in handicaps and disabilities. Therefore, prediction and prevention of NFI is extremely important in the management of leprosy. In 2000, a prediction rule for NFI was published, but circumstances have changed since the study was performed in the 1990s: the leprosy detection delay has shortened and the definition of NFI has changed. The original rule used ‘leprosy classification’ and ‘NFI present at diagnosis’ to predict future NFI. In the current patient population we studied an adjusted rule based on ‘leprosy classification’ and ‘presence of antibodies’. This adjusted rule predicted NFI more often than the original rule. With the adjusted rule it is now also possible to assess NFI risk before the first nerve damage event takes place. This may help doctors and health workers to improve surveillance for people at high risk. Early detection and treatment can then prevent permanent disabilities.

Early diagnosis of neuropathy in leprosy--comparing diagnostic tests in a large prospective study (the INFIR cohort study)

Background

Leprosy is the most frequent treatable neuromuscular disease. Yet, every year, thousands of patients develop permanent peripheral nerve damage as a result of leprosy. Since early detection and treatment of neuropathy in leprosy has strong preventive potential, we conducted a cohort study to determine which test detects this neuropathy earliest.

Methods and Findings

One hundred and eighty-eight multibacillary (MB) leprosy patients were selected from a cohort of 303 and followed for 2 years after diagnosis. Nerve function was evaluated at each visit using nerve conduction (NC), quantitative thermal sensory testing and vibrometry, dynamometry, monofilament testing (MFT), and voluntary muscle testing (VMT). Study outcomes were sensory and motor impairment detected by MFT or VMT. Seventy-four of 188 patients (39%) had a reaction, neuritis, or new nerve function impairment (NFI) event during a 2-year follow-up. Sub-clinical neuropathy was extensive (20%–50%), even in patients who did not develop an outcome event. Sensory nerve action potential (SNAP) amplitudes, compound motor action potential (CMAP) velocities, and warm detection thresholds (WDT) were most frequently affected, with SNAP impairment frequencies ranging from 30% (median) to 69% (sural). Velocity was impaired in up to 43% of motor nerves. WDTs were more frequently affected than cold detection thresholds (29% versus 13%, ulnar nerve). Impairment of SNC and warm perception often preceded deterioration in MF or VMT scores by 12 weeks or more.

Conclusions

A large proportion of leprosy patients have subclinical neuropathy that was not evident when only MFT and VMT were used. SNC was the most frequently and earliest affected test, closely followed by WDT. They are promising tests for improving early detection of neuropathy, as they often became abnormal 12 weeks or more before an abnormal monofilament test. Changes in MFT and VMT score mirrored changes in neurophysiology, confirming their validity as screening tests.

Leprosy is the most frequent treatable disease of the peripheral nerves. Yet, every year, thousands of patients develop nerve damage as a result of leprosy. If this is detected and treated early, the prognosis is good. We conducted the largest prospective study on this topic to date to determine which test would detect nerve damage earliest. One hundred and eighty-eight leprosy patients were selected from centres in North India and followed for 2 years after diagnosis. Nerve function was tested at each visit using a battery of nerve function tests. A large proportion of the patients had or developed subclinical nerve damage that was not detected with the standard clinical tests (monofilaments and voluntary muscle testing). Sensory nerve conduction was the most frequently and earliest affected test, closely followed by the warm temperature perception test. They are promising tests for improving early detection of nerve damage, as they often became abnormal 12 weeks or more before the monofilament test became abnormal. Changes measured with the monofilament and voluntary muscle tests mirrored changes in more advanced electronic measures, confirming their validity as screening tests. These findings open the door to future improvement of the prognosis of nerve damage in leprosy.

Corticosteroids for treating nerve damage in leprosy

BACKGROUND

Leprosy causes nerve damage which can result in nerve function impairment and disability. Corticosteroids are commonly used for treating nerve damage, although the long-term effect is uncertain.

OBJECTIVES

To assess the effects of corticosteroids on nerve damage in leprosy.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register, the Cochrane Central Register of Controlled Trials (Issue 4), MEDLINE (from 1966), EMBASE (from 1980), CINAHL (from 1980), LILACS (from 1982) in January 2006. We checked reference lists of the studies identified, the Current Controlled Trials Register (www.controlled-trials.com), conference proceedings and contacted trial authors.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of corticosteroids for nerve damage in leprosy.

DATA COLLECTION AND ANALYSIS

The primary outcome was improvement in sensory and motor nerve function after one year. Secondary outcomes were improvement in nerve function after two years, change in nerve pain and tenderness, and adverse events. Two authors independently extracted data and assessed trial quality. We contacted trial authors for additional information. We collected adverse effects and cost effectiveness information from the trials and non-randomised studies.

MAIN RESULTS

We included three randomised controlled trials involving 513 people. Two trials compared prednisolone with placebo. One trial treated mild sensory impairment of less than six months duration and the other trial treated nerve function impairment of 6 to 24 months duration. Both trials examined an effect twelve months from the start of treatment. There was no significant difference in nerve function improvement between people treated with prednisolone or with placebo. The third trial compared three corticosteroid regimens for severe type 1 reactions. This trial did not report the prespecified outcomes. However, after 12 months, a significantly higher proportion of individuals on a 3-month course of prednisolone required extra corticosteroids compared to the groups with a high-dose and low-dose regimen of five months duration. Diabetes and peptic or infected ulcer were sometimes reported as serious adverse events in the placebo-controlled trials, but not significantly more often in the corticosteroid than placebo groups.

AUTHORS' CONCLUSIONS

Corticosteroids are used for treating acute nerve damage in leprosy, but evidence from randomised controlled trials does not show a significant long-term effect. Randomised controlled trials are needed to establish their effectiveness, the optimal regimens and to examine new therapies.

Steroid prophylaxis for prevention of nerve function impairment in leprosy: randomised placebo controlled trial (TRIPOD 1)

OBJECTIVE

To determine whether addition of low dose prednisolone to multidrug treatment can prevent reaction and nerve function impairment in leprosy.

DESIGN

Multicentre, double blind, randomised, placebo controlled, parallel group trial.

SETTING

Six centres in Bangladesh and Nepal.

PARTICIPANTS

636 people with newly diagnosed multibacillary leprosy.

INTERVENTION

Prednisolone 20 mg/day for three months, with tapering dose in month 4, plus multidrug treatment, compared with multidrug treatment alone.

MAIN OUTCOME MEASURES

Signs of reaction, impairment of sensory and motor nerve function, and nerve tenderness needing full dose prednisolone at four months and one year.

RESULTS

Prednisolone had a significant effect in the prevention of reaction and nerve function impairment at four months (relative risk 3.9, 95% confidence interval 2.1 to 7.3), but this was not maintained at one year (relative risk 1.3, 0.9 to 1.8). Fewer events occurred in the prednisolone group at all time points up to 12 months, but the difference at 12 months was small. Subgroup analysis showed a difference in response between people with and without impairment of nerve function at diagnosis.

CONCLUSIONS

The use of low dose prophylactic prednisolone during the first four months of multidrug treatment for leprosy reduces the incidence of new reactions and nerve function impairment in the short term, but the effect is not sustained at one year. The presence of nerve function impairment at diagnosis may influence the response to low dose prednisolone.