Leprosy: report of a case with severe peripheral neuropathy.

Leprosy (Hansen's disease) is a chronic granulomatous infectious disease, caused by Mycobacterium leprae, with cutaneous and neurological manifestations. Leprosy is very rare in Europe but some cases are reported, especially among people coming from endemic areas. Here, we report a case of Hansen's disease and emphasize the importance of a prompt diagnosis and treatment also in non-endemic areas.

Sensitivity and specificity of nerve palpation, monofilament testing and voluntary muscle testing in detecting peripheral nerve abnormality, using nerve conduction studies as gold standard; a study in 357 patients.

OBJECTIVE: To determine sensitivity and specificity of clinical tools viz. nerve palpation (NP), monofilament (MF), and voluntary muscle testing (VMT), for assessing peripheral nerve function impairment (NFI) in leprosy, using nerve conduction studies (NCS) as gold standard. STUDY POPULATION AND METHODS: 357 untreated multibacillary (MB) leprosy patients were assessed using above tests. The nerves assessed were left and right ulnar, median, radial cutaneous, sural, common peroneal and posterior tibial. The concordance between the clinical and NCS tests was done for each nerve. The sensitivity and specificity of clinical tests for detecting nerve impairment was determined, using NCS as gold standard. Analysis was performed using SPSS version 10.0. RESULTS: The sensitivity of NP ranged between 71% to 88% for all nerves, except the median (43%) and sural (59%) nerves. Specificity was > 60% for all, but low for ulnar (34%) and common peroneal (40%) nerves. The specificity of MF testing was > 80% and of VMT assessment was >90% for all nerves. The sensitivity of MF testing ranged between 35-44%, while of VMT assessment was very low i.e. 4-5%, the maximum was for the ulnar nerve (25%). Detection sensitivity of MF testing and VMT assessment improved two fold when combined with NP and was closely comparable to NCS test findings. CONCLUSIONS: Both MF testing and VMT assessment showed good specificity, but moderate to low sensitivity. NP was less specific but more sensitive than MF testing and VMT assessment. Combining NP with MF testing and VMT assessment gives a two fold improvement in the sensitivity for assessing nerve damage and could therefore serve as the most useful clinical tools for diagnosis of leprosy and detecting nerve damage at field level.

Voluntary muscle testing and dynamometry in diagnosis of motor impairment in leprosy: a comparative study within the INFIR Cohort Study.

AIM: To evaluate hand muscle weakness detected through dynamometry as an indicator for change in motor nerve function detected by Voluntary Muscle Testing (VMT) of ulnar and median nerves. DESIGN: The research was carried out as part of the INFIR Cohort Study among 303 subjects newly diagnosed with MB leprosy in two centres in UP state, northern India. METHODS: To assess grip strength, key pinch and pulp-to-pulp pinch we adapted the cuffs of adult and neonatal sphygmomanometers. The testing was carried out at diagnosis and at each visit during a 2-year follow-up. RESULTS: 303 subjects with newly diagnosed MB leprosy were included in the study. We found statistically significant differences in grip strength, key pinch and pulp-to-pulp pinch between groups defined by ulnar VMT grades at time of diagnosis. There was also a statistically significant difference in hand grip between groups defined by median VMT at diagnosis. In each case, strength tended to reduce with increasing motor involvement. We explored reduction in grip strength, key pinch or pulp-to-pulp pinch as indicators of change in ulnar VMT during follow-up. A 25% reduction over two visits was the most effective indicator. Changes were also associated with marginal changes in motor and sensory nerve function, most commonly associated with Type I reactions. CONCLUSION: Dynamometry is recommended as an additional method that may be used to monitor changes in nerve function in leprosy, particularly in subjects with early motor impairment of the ulnar nerve.

Ensuring inter-tester reliability of voluntary muscle and monofilament sensory testing in the INFIR Cohort Study.

OBJECTIVE: To assess the reliability of monofilament (MF) and voluntary muscle strength (VMT) testing carried out by nine physiotherapy staff recruited for the ILEP Nerve Function Impairment & Reaction (INFIR) Cohort Study in India. DESIGN: A multiple pair inter-tester reliability study was carried out in Uttar Pradesh, India. Newly trained testers were paired up with an experienced physiotherapist, whose assessment served as the gold standard. Each pair completed a series of assessments. All testers had undertaken a week of specific VMT and MF training, followed by a month of practice in the hospital setting. Reliability was assessed by calculating weighted Kappa (Kw) statistics, which may be interpreted as the chance-corrected proportion of agreement between testers. RESULTS: Eight newly-trained physiotherapists and one physiotechnician took part in the study. In the early stages of the study some areas of weak agreement were identified and correct assessment technique was reviewed, particularly for the eye. Good to very good reliability (Kw 0.62 to 0.99) was found for all sensory tests and most muscle strength tests. The only lower Kw scores (0-48 to 0-59, suggesting only moderate reliability) were for the VMT of muscles supplied by the median nerve in one of the study's two field centres. Even in this case, testers never varied by more than one grade, but calculation of Kw was negatively influenced by a lack of variation among the subjects. In addition, testers never varied by more than one grade from the gold standard. CONCLUSION: Even though all testers were professionally trained and received additional specific training and practice in MF and VMT testing, discrepancies in technique required an early review and correction. This fact highlights the need for careful training and formal reliability testing. This should extend to referral centres where staff are involved in assessing the symptoms of reaction and monitoring response to treatment. Reliability testing provides the opportunity to address important discrepancies in technique that may persist even in the presence of protocols and qualified and trained staff. It is therefore a valuable tool as part of a training procedure for situations, where patients may be assessed by different testers. Overall, our results were deemed good enough to proceed with the INFIR study, using VMT and MF testing as a baseline against which to compare more sophisticated methods of nerve function testing.

Monitoring motor nerve function in leprosy patients.

Manual muscle strength testing has an important function in the management of leprosy patients. Its importance was first recognized in the 1960s, especially when following patients who were started on steroid treatment to monitor the nerve function and the effect of treatment. In those days, and still in many centres today, many or all muscles were tested that are innervated by the nerves that can be at risk in leprosy. The author argues that not all muscles innervated by the nerves at risk need to be tested and also that many muscles cannot be tested in isolation. A muscle charting form is presented which is suitable for screening purposes, and that also allows for more detail when motor function is impaired.

Skin and muscle vasomotor reflexes in detecting autonomic dysfunction in leprosy.

There are few tests to assess the function of small unmyelinated nerve fibers. One established test is the skin vasomotor reflex (SVMR), which uses laser doppler flow velocimetry. The SVMR has the disadvantages of being susceptible to interference (from change of temperature and alerting stimuli) and of requiring expensive equipment. An ultrasound doppler method, which is less expensive, can be used to detect muscle vasomotor reflex (MVMR) activity. We sought to compare the efficacy of these two methods in detecting dysfunction of small unmyelinated nerve fibers in patients with leprosy. SVMR was shown to be less sensitive (P < 0.01) and specific (P < 0.001) than MVMR. The favorable results of MVMR may be attributed to its lesser susceptibility to interfering sympathetic vasoconstriction from alerting stimuli. MVMR also reflects larger areas of blood vessel innervation than the laser doppler method. In leprosy, nerve damage is typically patchy and may be missed by the smaller sampling of the laser method.

Split flexor carpi radialis muscle.

A detailed anatomic and intramuscular neural staining study in 22 human and 5 monkey upper limbs revealed that the flexor carpi radialis can be raised on its proximal neurovascular pedicle and that the muscle can be split along its tendon into two independently functioning neuromuscular compartments, each with its own nerve and blood supply. A study of the muscle architecture in the human specimens found the radial compartment to have significantly longer fiber length and a larger physiologic cross-sectional area than the ulnar compartment. Independence of function of each compartment was demonstrated in electrical stimulation studies in six monkeys (Macaca fascicularis), but no significant difference was noted in the peak isometric load between the two compartments (p = 0.68) in the monkey. The extra functioning muscle units become important in local transfers for restoring function in multiple nerve palsies as in Hansen's disease, severe traumatic loss of muscle in crush injuries and compartment syndromes, and after wide resection in infective and neoplastic conditions in the forearm and hand.

Regenerative changes in median nerve defects using various rabbit skeletal muscles.

We examined the morphological changes of median nerve regeneration which situated to pass through degenerative latissimus dorsi and brachial triceps muscles in rabbits. Morphological observation was performed at 7, 14, 28, 45, 60 and 180 days after the creation of defect of the bilateral median nerves. Regenerative nerve fibers were observed in the residual tubes of left degenerative muscle bridges. In this respect the regenerative effect of the latissimus dorsi was better than that of the brachial triceps. These results suggest that regular and longer muscle fibers as those of latissimus dorsi may contribute to the effective regeneration of nerve.