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.

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.

Restoration of sensibility in irreparable ulnar and median nerve lesions with use of sensory nerve transfer: long-term follow-up of 20 cases.

A prospective study was conducted to evaluate patient outcomes following sensory nerve transfer. Twenty patients with irreparable ulnar or median nerve lesions underwent the procedure. Nerve involvement was bilateral in 5 cases. The mean age of the patients at the time of surgery was 29 years. The mean paralysis time and the average length of follow-up were 59 and 78 months, respectively. Eighteen of 20 patients attended a sensory re-education program after surgery. Outcome was assessed objectively by functional sensory recovery testing and by the British Medical Research Council standards. Subjective outcome was assessed by a questionnaire. Two-point discrimination of less than 10 mm was achieved in 15 of 25 hands. The mean functional sensory recovery score was 83. Eighteen of 20 patients reported that the function of their hands improved after the procedure. Good or excellent results were associated with immediate transfer of the nerve, young age, and patients' attendance to the sensory re-education program after surgery. No differences were found between the recovery of ulnar and median nerves. Based on these results we suggest that sensory nerve transfer is a simple and reliable way of restoring sensibility to the hand with favorably comparable results over conventional nerve grafting in selected cases.

Clinical and electrophysiological evaluation of nerve function impairment following cessation of multidrug therapy in leprosy.

Seventeen multibacillary (MB) and 15 paucibacillary (PB) cases of leprosy who had had regular and adequate multidrug therapy (MDT) were examined clinically and electrophysiologically at periodic intervals for 1 year following cessation of MDT. All the major nerves were assessed for nerve function impairment (NFI). Overall, two MB (13.3%) and three PB (20%) cases showed signs of deterioration clinically and/or electrophysiologically. The nerve conduction (NC) follow-up studies revealed no significant improvement in the sensory conduction in both the MB and PB groups of nerves, whilst motor conduction showed a significant improvement at the first 6-monthly follow-up among the MB group of nerves. At the study onset, sensory impairment (MB = 62%, PB = 25%) predominated over motor in terms of both severity and frequency. The lower extremity was more frequently and severely affected than the upper in both groups of patients. As an individual test, NC measurement proved to be more sensitive in detecting NFI, but the combination of physical palpatation for nerve thickening and graded nylon test (GNT) was closely comparable to measurement of nerve conduction.

A field trial of detection and treatment of nerve function impairment in leprosy--report from national POD pilot project.

As part of a collaborative project between the Ministry of Health of China (MOH) and The Leprosy Mission International (TLMI) on leprosy rehabilitation and prevention of disability (POD), a total of 1407 patients was monitored for possible nerve function impairment (NFI) through standardized clinical nerve function assessment between May 1995 and February 1998. Of these, 191 patients were found to have NFI and were put on a fixed regimen of prednisolone. In this study, 36.7% of NFI occurred before diagnosis of leprosy, 35.6% developed during MDT and 25.7% after their release from MDT. Overall, 7.5% (105 out of 1407) of all patients, or 55.9% of patients with NFI, suffered from silent neuropathy. Of the affected nerves, 62.6% had silent neuropathy. Sensory impairment responded to prednisolone satisfactorily, giving a recovery rate of 73.8%, 76.5% and 81.0% in ulnar, median and posterior tibial nerve, respectively. Sensibility in patients even with a NFI duration longer than 6 months made significant improvement (p < 0.05). Motor function improvement was less satisfactory, especially in ulnar and c. popliteal nerve. The possible reasons are analysed. Our findings with regard to sensibility changes confirm that once it becomes clinically detectable, NFI is no longer at the 'early' stage. More sensitive tests are necessary to detect real 'early' sensory impairment in the field. Our study also indicates that with well-trained field staff and proper equipment for nerve function assessment, early detection and treatment of NFI can be practical and effective.

Intranasal anaesthesia in lepromatous leprosy.

Intranasal sensation was assessed in a group of 25 lepromatous leprosy patients. It was found that 17 patients showed partial or complete impairment of intranasal common sensation. The intranasal anaesthesia is found to be related to the advancement of intranasal disease. Loss of sensation may lead to repeated trauma, ulceration and epistaxis, due to repeated 'picking' of the nose in an attempt to remove the crustings. It is suggested therefore, that the lepromatous leprosy patient should be taught to take care of the nose just as they are instructed in the care of their hands and feet.

Sympathetic vasomotor dysfunction in leprosy patients: comparison with electrophysiological measurement and qualitative sensation testing.

Testing of skin vasomotor reflexes (VRs) by laser Doppler flowmetry (LDF) is now a recognised method of measuring peripheral dysautonomia. To assess its specificity as an indicator of impairment to unmyelinated autonomic fibres, VR testing at the fingerpulp was compared with standard qualitative sensation (QST) and with sensory electrophysiological (SNVC) measurements in 39 Iranian leprosy patients. There was a significant relationship between VR and SNCV values (but not QST): these were jointly measurable in 38.5% of fingers, and jointly absent in 35.3% of fingers which also showed significantly reduced LDF perfusion and skin temperatures. However, in 10.3% of fingers, predominantly index and otherwise apparently healthy, VRs were absent but SNCV present, suggesting early sub-clinical autonomic impairment. In a further 16% of fingers, predominantly ulnar and with poor microcirculation, intact (though impaired) VRs could be recorded despite the absence of SNCV responses, suggesting sparing or regeneration of these fibres. This evidence suggests that where there is heterogeneity of nerve damage a combination of VR and electrophysiological testing can indicate the functional status of distinct fibre types.

Corneal sensitivity in patients with leprosy and in controls.

AIMS: In a quantitative prospective study the corneal sensation in patients with leprosy was compared with age matched controls. METHODS: The patients with leprosy were classified as paucibacillary and multibacillary and were divided in three groups: (1) patients without clinically detectable eye pathology; (2) patients with lagophthalmos, (3) patients with signs of iridocyclitis. The corneal sensitivity was assessed with the Cochet and Bonnet aesthesiometer. RESULTS: There was a significant decrease in corneal sensitivity in multibacillary patients without clinically detectable eye pathology and in patients with lagophthalmos or iritis when compared with controls. A significant correlation between the loss of power of the orbicularis oculi muscle and the degree of corneal sensation loss could not be established. No significant decrease in corneal sensitivity was found in paucibacillary patients without eye pathology compared with the control group. CONCLUSION: The results of this study showed that loss of corneal sensation can occur while there is no clinically detectable eye pathology, at least in multibacillary patients. Regular checkups of the corneal sensation should, therefore, be part of the routine control of leprosy patients. Health education on eye care and early warning signs should be encouraged.

The predictive value of sensation testing in the development of neuropathic ulceration on the hands of leprosy patients.

The early detection of the loss of protective sensation in leprosy patients is vital if neuropathic ulceration and subsequent disabilities are to be avoided. The aim of this study was to find protective value of sensory thresholds in the hands of leprosy patients. Thresholds for touch-pressure, vibration and temperature were assessed in areas on leprosy-affected hands near ulcers or ulcer scars (LU-group), in areas without lesions (LN-group), and in controls (N-group). Semmes-Weinstein monofilaments were used for testing the touch-pressure threshold (PST), a biothesiometer for the vibration threshold (VST) and a Thermo Sensation Tester for the temperature threshold (TST). The distribution of ulcers was about equal on palmar and dorsal aspects of the hands. In the LU-group there was a negative response to SWF of 2.0 g in all patients, while 74% could feel the 2.0 g in LN-areas and in N-areas 100% could detect the 2.0 g SWF. In the LU-group about 11% felt 8 V VST, in the LN-group about 60% and in the N-group 89%. Testing temperature sensation was given up prematurely because the results in controls were unsatisfactory. Both palmar and dorsal sides of the hands should be tested for sensation. The thresholds for protective sensation are 2.0 g SWF and 8 V for vibration sense. It is recommended that Semmes-Weinstein monofilaments should always be used for early detection of loss of protective sensation.