Early nerve damage in leprosy: an electrophysiological study of ulnar and median nerves in patients with and without clinical neural deficits.

BACKGROUND: Peripheral nerve trunk involvement in leprosy is very common. However, by the time it becomes clinically manifest, the damage is quite advanced. If the preclinical nerve damage can be detected early, the deformities and disabilities can be prevented to a large extent. AIMS: To assess the electrophysiological functions of the ulnar and median nerve trunks in cases of clinically manifest leprosy with and without manifest nerve damage at different durations of nerve damage. MATERIALS AND METHODS: Electrophysiological functions of ulnar and median nerves were studied in leprosy patients, both normal and at different stages of disease and damage. PB cases, having disease for six months or less, without neurological symptoms and clinically normal appearing nerve. STATISTICAL METHODS: Mean was taken of different values. The changes in values of different parameters were expressed as percentage change with reference to the control values (increase or decrease). RESULTS: Reduced nerve conduction velocities and changes in latency and amplitude were observed. Changes in sensory nerve conduction were more pronounced. Sensory latencies and amplitude changes were more severe than motor latencies and amplitudes in cases with manifest muscle palsies. Changes in MB cases were less marked. CONCLUSIONS: Further studies are needed to identify parameters likely to be helpful in the diagnosis of early nerve damage.

Prevention-of-impairment-and-disabilities activities in leprosy after integration: role for physical medicine and rehabilitation personnel.

Referral options for specialist care for prevention of impairment and disabilities are imperative in order to make an integrated leprosy control system work. This requires an understanding of the disease, in addition to the special skills for managing specific disabilities. Physical medicine and rehabilitation (PMR) personnel are better equipped to handle leprosy-related disabilities. They are well versed with biomechanical aspects of deformities, and are competent to provide splints, orthoses, etc. to the needy persons, and they can assess sensory motor functions and deformities. If PMR personnel can be trained in deformity correction they can become valuable resource persons for secondary and tertiary care of leprosy-affected persons. PMR persons, therefore, have the opportunity to volunteer themselves for this job to fill the void created by the fading out of leprosy surgeons. They will also have to bear additional responsibility to train general health care workers so as to empower them to look after the needs of those disabled by leprosy, many of whom will continue to be available for a number of years to come.

Dynamic procedures for claw-finger correction--dilemma of balancing tension in transferred tendon slips.

The critical step in dynamic claw-finger correction procedures is adjustment of tension on the tendon slips which are being sutured at the new insertion sites to correct finger-clawing. Several methods to balance and adjust the tension have been described ever since these procedures have been in use. Ultimately it is the experience of the operating surgeon that helps to decide as to the tension that is to be kept on each slip so that maximum deformity correction is obtained without compromising the functional capabilities of the hand. An attempt has been made to describe this "experience" in words so that the surgeons who perform these corrective surgical procedures for the first time have some criteria to guide them.

Flexor digitorum superficialis--revisited.

Flexor digitorum superficialis (FDS) is a median nerve innervated forearm muscle, and is usually available for transfer in palsied hands because of leprosy. Middle and ring finger FDS tendons have been preferably used in these procedures. The removal of FDS from fingers, to be used as motor elsewhere, has its own advantages and disadvantages. Many people think of FDS as four, more or less independent, muscles that may lead to problems when these tendons are used for non-synergistic transfers. Central to FDS muscle mass in forearm is a large flat common tendon that connects a single proximal muscle belly to two or three separate distal muscles, thus forming a complex digastric muscle. The muscle to middle finger tendon is totally independent. The anatomy of FDS muscle, functional capabilities of FDS tendons in different fingers, and the effects of removal of tendon from fingers have been discussed in the present article.

Closure of simple heel ulcers by skin stretching.

A majority of heel ulcers, at least to begin with, extend to dermis or to the fat pad in its superficial part and an appropriate skin closure can heal these ulcers as most of the padding is in tact. Since the skin is adherent to the deeper structures with fibrous bands it has to be stretched or undermined (by cutting the fibrous bands) to close the wound without tension. 17 feet in 11 patients (10 males; one female) in the 12-54 year age-group were operated upon and followed up. Because skin is adherent to deeper tissues by fibrous septae, stretching of skin was planned to mobilize it for a tension-free closure. Of the 17 feet, 13 could be re-examined after 30 months or more. Most of the minor recurrences were seen in the first 6 months after surgery. Major recurrences were seen in 2 feet (one case). The suture line did not show hyperkeratosis and the scar merged well into the surrounding skin after one year. Available data suggest that simple heel ulcers can be made to heal with a good scar by skin-stretching and suture, and, by radiography of the foot, it is worth separating those cases in which ulcer is not extending deep involving calcaneum. The size of the ulcer in heel is important for the success of the operation. The procedure is not intended for big wounds (>15 mm in width).

Shall we continue with nerve trunk decompression in leprosy?

There is a tendency to compare the results of surgery with that of oral corticosteroid therapy in leprous neuritis as if the two are competing methods. Surgery helps by removing the external compressive force and improves circulation so that steroids can reach and effectively act at the site of inflammation, minimizing the ischaemic and compression damage to nerve fibres. Often nerve decompression in leprosy is requested rather late so that the desired results are not always achieved. With emphasis on "elimination of leprosy", the disease is being managed in endemic states by field programmes where individual patient is not the priority unlike in the general hospitals and among practitioners where the welfare of the patient is the priority. It is therefore important to create awareness about compression neuropathy in leprosy and the need for combination therapy so as to bring down the morbidity and disability.

Lasso procedure to correct finger-clawing in leprosy using index or middle finger flexor digitorum superficialis split into four tails--a long-term follow-up study.

For obvious reasons, the use of flexor digitorum superficialis (FDS) from the ring finger, for correction of finger-clawing, is usually not recommended in leprosy. Hence, one has to choose either index or middle finger FDS for correction of finger-clawing. No significant differences could be made out when follow-up data of claw-finger correction by modified lasso procedure, using FDS either from index or middle finger, were compared. In some hands post-operative problems, such as stiffness, superficialis minus deformities of proximal interphalangeal joints (PIPJ) and distal interphalangeal joints (DIPJ), were noted. As revealed by finger dynamography, the working space of the hand was not found to be fully restored, the donor finger showing distortion of its working space.

Palmaris longus--a muscle with multiple uses in leprosy-affected hands.

The present paper reviews the anatomy of palmaris longus muscle and also the situations where palmaris longus muscle has been used as an independent motor or as a donor of tendon graft material. Its relevance in leprosy-affected hands is also discussed because the muscle is usually spared in hand palsies consequent to leprotic neural damage. The advantages and disadvantages of its use in different operative procedures have been analyzed. The author's experience with this muscle in the correction of hand deformities in leprosy is described.

Comparative evaluation of effectiveness of different motor muscles in modified lasso procedure for correction of finger clawing

A retrospective study was carried out to compare the effectiveness of different muscles as motors in modified lasso procedures for correction of finger clawing in leprosy. It was observed that palmaris longus and extensor carpi radialis longus were more suitable than the flexor digitorum superficialis. In some patients, removal of superficialis is associated with complications which could not be predicted before surgery. Extensor carpi radialis longus has advantages over palmaris longus in selected cases.

Median nerve palsy following claw finger correction in leprosy: effect of M. leprae or a consequence of surgery.

Median nerve palsy, though not a frequent occurrence after claw finger correction, does exist as a post-operative complication after claw finger correction. A retrospective study was carried out to examine the occurrence of post-operative median palsy, in cases of isolated ulnar palsy, where the transferred motor tendon was routed through the carpal tunnel. We noted that six patients developed median nerve palsy following claw finger correction. Median palsy developed at different times after surgery--the "early onset" type developing within three weeks post-operatively, "reactional" type developed when patient was undergoing physiotherapy exercises and learning to use the transfer and "delayed insidious" type presenting six months or more after operation. We could not succeed to get the true prevalence of such occurrences because all the operated hands could not be re-examined.

Rehabilitation of insensitive hands.

This article highlights the physical, social and emotional problems faced by persons with insensitive hands and problems of disuse, misuse and overuse. Evaluation of sensation and residual functional capabilities is the first step in planning the process of rehabilitation. Acceptance of disability by the patients and their attitude are important for successful rehabilitation. Possible solutions are suggested.

Protective sensibility--its monofilament nylon threshold equivalents in leprosy patients.

An attempt has been made to definite the levels of "protective sensibility" in terms of perception thresholds to monofilament nylon induced touch/pressure stimuli. Certain problems were observed while interpreting the observations. There appears to be a range of threshold values instead of a clear cut-off point. We suggest that a monofilament nylon stimulus two times the normal threshold value for that patient be taken as cut-off point. This will make the observations of Birke and Sims (1986) and Hammond and Klenerman (1987) reasonable without having any need to exclude the cases who defy the boundaries laid by them. Since the genesis of plantar ulcer is multifactorial, it appears logical to include all patients who have a certain degree of hypoaesthesia, for special ulcer care program. The likely problems while using monofilament nylons in the field and their possible solutions have also been outlined.

Sensory functions in limbs of normal persons and leprosy patients with peripheral trunk damage.

The threshold to touch was tested in hands and feet of normal persons using Semmes-Weinstein graded monofilament nylons. The minimum stimulus to which response could be elicited was nylon number 3.61 in palms and 4.31 in soles. These numbers relate to the logarithm of the force applied, 3.61 corresponding to 0.217 gm force and 4.31 to 2.35 gm force respectively. The area of pain insensitivity complained by the patient more or less corresponds to that revealed by objective testing. It was interesting to observe that loss of pain sensitivity was confined to a smaller area compared to touch and thermal insensibility in the part innervated by the same nerve trunk.

An ultrastructural study of Schwann cells in peripheral nerves of leprosy patients.

An ultrastructural study of peripheral nerves in leprosy patients was carried out of ascertain the changes in Schwann cells containing myelinated and nonmyelinated axons. Axonal multiplication was noticed in nonmyelinated axons in specimens from both tuberculoid and lepromatous leprosy. The Schwann cells in tuberculoid nerves were devoid of M. leprae in contrast to those in lepromatous nerves in which large number of bacilli were seen. These observations suggest that the Schwann cells containing nonmyelinated axons may be affected more frequently in either type of leprosy.

Ultrastructural studies of peripheral nerves in lepromatous leprosy patients.

Ultrathin sections of the peripheral nerves taken from three lepromatous leprosy patients (One untreated, other treated and third in ENL reaction) was examined in the electronmicroscope. In the untreated patient, solid M. leprae organism inside the schwann cell and the degeneration of schwann cell was seen. In contrast, the treated patient showed the degeneration of bacilli and myelinated fibres. However, the characteristics of cells in the ENL reaction showed close similarities with the untreated case.