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Clinical and electrophysiological study of leprous neuritis.


Leprosy is one of the principal causes of non-traumatic neuropathy and clinically manifests as hypopigmented anaesthetic patches of skin with involvement of peripheral nerves. Functional derangement of nerves can be shown by nerve conduction studies before appearance of clinical signs and symptoms of the disease. Functional defect in conduction velocity in nerves always precedes clinical manifestation. Role of electrophysiological evaluation of nerve function in the diagnosis and assessment of various neuropathies has been studied.

Aims and Objectives

1. To detect nerve function impairment at early stage.

2. To correlate clinical involvement of nerve and the corresponding electrophysiological changes.

3. To know specific electrophysiological changes of peripheral nerves in different types of leprosy.

4. To assess nerve function impairment along with other standard tests.


The present study comprises of 50 new cases of various types of Leprosy who attended Department of Dermatology, King George Hospital, Visakhapatnam during the period from September 2004 to August 2005. All these cases were clinically examined along with relevant investigation including slit-skin smear. These cases were subjected to nerve conduction studies in the Department of Neurology to assess the motor and sensory involvement.

Inclusion Criteria

New cases of all types of leprosy.

Age >= 10 years.

Exclusion Criteria

Patients in reaction.

Patients already on steroid therapy.

Other systemic illnesses.

Clinical history was taken and classified patients according to Ridley-Jopling classification. Routine haematological, biochemical and standard tests for nerve function impairment were done. Slit-skin smear was done in all cases (3 smears-1 from earlobe, 2 from patches). Nerve conduction studies were done by Medicaid two channel digital EMG NCV-NP2300W, Dept. of Neurology. Nerves tested were Median, Ulnar, Radial, Peroneal, Tibial, Sural nerve.

Procedure of NCS

After preparation of the skin, square wave stimuli of 0-500 volts amplitude and 0.1 msec duration were applied to the skin along the distal end of nerves at frequency of 1 per second using disc electrodes and ring electrodes.
Electrode Position for Nerve Conduction Study

Nerve    Stimulating          Recording
         Electrode            Electrode

         2 cm proximal to     12 cm proximal to
RCI      metacarpal head of   stimulating electrode
         index finger.        along the radial nerve
                              12 cm proximal to
Sural    2 cm below           stimulating electrode
         lateral malleolus    along the nerve in
                              mid-calf region.
Median   Wrist                Cubital fossa
Ulnar    Dorsa of palm        2 cm below or 2 cm
         ulnar border         above medial epicondyle

For Motor Nerve Conduction

Active electrode is placed over the motor point which is usually at the midpoint between the origin and insertion of the muscle. The reference electrode is placed on the tendon. Surface stimulation of nerves with intensity of 5-40 m amperes current done. The measurement of MNC includes latency, duration, amplitude and compound action potential are recorded.

For Sensory Nerve Conduction Studies

Both active and reference electrodes were placed on the nerve, electrode minimum distance is 4 cm, the surface electrodes were placed with the help of electrode paste which provides interface between the patient and the equipment. After surface stimulation of the nerves, SNAP amplitude is measured. Velocity is measured by stimulating at a single site and the remaining measurements were similar to motor nerve conduction studies.


Study period September 2004 to August 2005.

* Total number of cases--50

* B. T. Hansens--30

* B. B.--03

* B. L.--07

* L. L.--01

* P. N.--09
Age and Sex Distribution of the Cases

Age      Male   Female

10--20   12     03
21--30   14     07
31--40   04     02
41--50   02     01
51--60   02     02
61--65   01
         35     15

Duration of the Disease

1 month to 4 years Neurological Study results.
Neurological Manifestations in
Different types of Leprosy Patients

Neurological                LL   BL   BT   TT   PN   Total
Cranial nerves affected
Trigeminal nerve            1    3    2              6
Facial nerve                          3              3
Muscular system
Disability claw hands            2    2         1    5
Flexion deformity of toes        1              1    2
Muscles wasting
Upper limbs                      2    2         1    5
Lower limbs                      1    1         3    5
Sensory system
Superficial sensation
Mononeuropathy                        11        4    15
Ulnar side
Radial side                      2    2         1    5
Glove and stock             1
Maculo-anaesthetic          1    7    30             38
Trophic and vasomotor
changes anhydrosis               4    12             20

Cranial Nerves

The trigeminal nerve was the most common cranial nerve being involved in 6 cases out of 50 cases. The predominant manifestation of trigeminal nerve affection were mainly sensory manifestations in the form of hypoesthesia of face in 3 patients, anaesthesia of face in 3 patients, and loss of corneal reflexes in 6 patients. Other cranial nerve involved was facial nerve in 3 cases. One case with facial nerve involvement was manifested by lagophthalmos, there was severe inflammatory swelling of the whole right side of face and watering from the right eye.

Muscular System

The commonest disabilities in muscles were manifested by complete claw hand in 2 cases, partial claw in 3 cases and foot drop in 3 cases.

Wasting of the hands and forearm in 5 cases, wasting towards ulnar side flexors of the wrist, finger and thumb extension in 3 cases, unilateral wasting in thenar in 5 cases, bilateral distal wasting in 2 cases. In lower limbs, 3 foot drops cases, wasting in 3 cases, wasting of distal leg muscles towards peroneal side 3 cases, wasting of foot muscles.

Sensory System

Superficial sensation was most affected, diminished in almost all cases as shown.

Trophic and vasomotor changes: Anhydrosis in 21 cases, thickened ulnar nerve found in 31 cases unilateral, 5 cases bilateral ulnar thickening, thickened and great auricular nerve in 6 cases, thickened radial cutaneous nerve in 4 cases, thickened medial cutaneous nerve of forearm in 1 case, thickened cutaneous nerve of upper arm on right side, thickened common peroneal nerve in 17 cases. Thickened posterior tibial nerve in 8 cases, thickened sural nerve in 3 cases, thickened median nerve in 6 cases.

Nerve Conduction Results- Normal values for Representative Nerve Conduction Values at various sites of Stimulation (Mean values + 2 SD for adults 16 to 65 years of Age).
Motor Nerve Conduction Studies

           Distal        Other         Recording   Onset Latency (ms)
Nerve      Stimulation   Stimulation   Site
           Site          Sites                     ULN    125   150

                                                          %     %
Medial     Wrist         Elbow         APB         <4.2   502   6.3
Ulnar      Wrist         BG, AG        ADM         <3.4   4.2   5.1
Radial     Forearm       Elbow, SG     EIP         <5.2   6.5   7.8
Peroneal   Ankle         BFH, AFH      EDB         <5.8   7.3   8.7
Peroneal   BFH           AFH           TA          <3.0   3.8   4.5
Tibial     Ankle         PF            AH          <6.5   8.1   9.8

           AMP (mV)     CV (m/s)   Distance   f-latency
           LLN    80    LLN   80   (cm)       ULN   125

                  %           %                     %
Medial     >4.4   3.5   >49   39   6-8        <31   39
Ulnar      >6.0   4.8   >49   39   5.5-7.5    <32   40
Radial     >4.0   3.2   >50   40   10         NA
Peroneal   >2.0   1.6   >42   34   6-11       <58   72
Peroneal   >5.0   4     >42   34   10         NA
Tibial     >3.0   2.4   >41   33   6.8        <59   74

Sensory Nerve Conduction Studies

Nerve    Distal        Recording   Onset     Peak
         Stimulation   Site        latency   Latency
         Site                      (ms)      (ms)

Median   Wrist         Digit 2     < 2.5     < 3.5
Ulnar    Wrist         Digit 5     < 2.1     < 3.0
Radial   Forearm       Wrist       < 1.9     < 2.8
Sural    Calf          Ankle       < 3.2     < 4.4

Nerve    AMP    CV      Distance
         (mV)   (m/s)   (cm)

Median   > 20   > 52    13
Ulnar    > 15   > 52    11
Radial   > 20   > 48    10
Sural    > 6    > 42    14

AG--Above ulnar groove, BG--Below ulnar groove, AFH--Above fibular head, BFH--Below fibular head, SG--Spiral groove, TA Tibialis anterior, EDB--Extensor digitorum brevis, EIP--Extensor indicis proprius, ADM--Abductor digiti minimi, APB--Abductor pollicis brevis, AH--Abductor hallucis, PF--Popliteal fossa. Sensory studies were performed antidromically, amplitudes were measured from baseline to negative peak of SNAP.
Ulnar Motor       P.B. Patients      M.B. Patients
Nerve Variables   (n = 30)
                  Range     Mean     Range Mean

CV m/s            0-71.79   55.58    0-52.17 44.3
D.L. ms           0-20.51   10.472   0-3.5 5.99
Amp mV            0-23.57   33.539   0-29.35 10.472

m/s = meters per seconds, ms = milliseconds, mV - millivolts

There is a significant reduction in NCV and amplitude and reduced latency in MB cases when compared to PB. In 3 cases of multibacillary leprosy, motor component of ulnar nerve could not be elicited with maximum stimulation.
Sural Nerve Conduction Results in Leprosy Patients

Sural Nerve   P.B. Patients     M.B. Patients
Sensory       (n = 22)          (n - 14)
Variables     Range     Mean    Range     Mean

CV m/s        0-61.9    42.54   0-52.46   13.32
D.L. ms       0-5.1     2.32    0-3.25    0.86
Amp mV        0-42.31   16.25   0-15.50   3.51

There is a significant reduction in the nerve conduction velocity in all MB cases when compared to PB cases, in 10 cases of MB and 4 cases of PB the sural nerve could not be elicited even with maximum stimulation.
Motor Nerve Conduction Results of
Common Peroneal Nerve

Motor Nerve    PB patients       MB patients
Variables of   (n = 12)          (n-07)
CPN            Range     Mean    Range    Mean

CV m/s         0-58.82   40.99   0-52.4   34.6
D.L. ms        0-24.62   8.47    0-16.4   9.4
Amp mV         0-24.62   5.16    0-16.6   4.2

There is a significant reduction of NCV and slight reduction in amplitude and prolongation of D.L. in MB cases when compared to PB cases, in 3 cases of MB the nerve could not be elicited even with maximum stimulation.
Nerve Conduction Results of Posterior Tibial Nerve

PTN          P.B. Patients       M.B. patients
Conduction   (n = 12)            (n - 08)
Variables    Range       Mean    Range       Mean

CV m/s       0-58.02     41.69   0-56.25     36.34
D.L. ms      0-19.25     5.82    0-21.3      6.46
Amp mV       0.38-22.4   11.23   9.46

There is a slight reduction in NCV and amplitude and slight increase in DL in MB cases when compared to PB cases, in 1 MB case the PTN could not be elicited even with maximum stimulation.
Facial Nerve Conduction Results

Facial nerve           PB-3
Conduction variables   Range       Mean

DL                     2.62-9.68   6.2
Amplitude              2.23-2.98   2.52

There is a slight reduction in amplitude of facial nerve and increase in the DL.
Clinical & Electrophysiological Correlation
of Peripheral Nerves in Leprosy

Nerves   Clinically   Clinically   Electrophy-    Electrophy-
         Involved     Not          siologically   siologically
                      Involved     Involved       Not Involved

Facial                             2
Radial   4                         4
Ulnar    36                        27             9
CPN      17                        4
PTN      8                         1
Sural    3                         14

There is a significant clinical and electrophysiological correlation seen only in ulnar and radial nerves. 17 CPN & 8 PTN were clinically thickened and palpable but only few cases (4 CPN & 1 PTN) were having significant and specific electrophysiological changes.


Early detection of neuropathy and therapy plays an important role in prevention of disabilities and deformities which is an integral part of leprosy control programs. Electrophysiological studies of peripheral nerves may help to detect neuropathy at an early stage. Though sural nerve not palpable clinically, nerve conduction studies showed marked electrophysiological changes correlated with the study by Van Brakel and Khwas et al. [1] In our study, 14 cases of sural, 5 cases of ulnar though clinically unaffected, nerve conduction studies showed significant reduction in amplitude. Similar observations were made by Ramakrishnan and AG Srinivasan. [2] There is delay in nerve conduction velocity in all MB cases compared to PB cases. This is comparable with study by Sheela V. Donde. [3] In our study, median sensory component was more commonly affected than motor component compared with study by Soyal and Samanth et al. [4] In our study, 5 claw hands and 1 lagophthalmos detected by electrophysiological studies. In our study, lower limbs were severely affected than upper limbs, sensory more involved than motor comparable to Soyal et al. [4] In our study of 50 cases, peripheral neuropathy was variable compared to Goel et al. [5] In our study neurological and electrophysiological abnormalities were related to duration of disease in 10 MB cases compared to Brown T.R et al. [6] In our study, 10 MB cases showed diffuse involvement in most of the peripheral nerves compared to PB correlated with study by Tzourio et al. [7] In our study, mononeuritis of ulnar nerve was observed in 11 cases and it was the commonest nerve affected compared with study by S Talwar et al. [8] In this study, pure neuritic cases constitute about 18% compared with study by Kumar B et al. [9] In our study, motor component of ulnar nerve was more affected than motor component of median nerve compared to study by Antia et al. [10] There is a markedly significant increase in stimulating strength in all patients even in cases with normal conduction velocities. It indicates strength of the stimulus used is very sensitive and an important test for early detection of nerve involvement comparable to study by DD Palende et al. [11] Electrophysiological studies are only supplementary to clinical and standard tests to detect nerve function impairment. These tests are simple and noninvasive.


All patients of leprosy should have nerve function assessment in every visit during first year of treatment. Regular nerve function assessment is essential to detect silent neuropathy to prevent permanent disabilities and deformities. Hence, nerve conduction studies along with these tests may definitely help to assess the damaged nerves in leprosy.


[1] Van Brakel WH, Khawas IB. Silent neuropathy in leprosy; an epidemiological description. Lepr Rev 1994;65(4):350-60.

[2] Ramakrishnan AG, Srinivasan TM. Electrophysiological correlates of hanseniasis. Int J Lepr Other Mycobact Dis 1995;63(3):395-408.

[3] Donde SV, Shah A, Antia NH. Nerve conduction in leprosy: in vivo and in vitro study. Lepr India 1983;55(1):12-21.

[4] Soysal A, Atay T, Ozu T, et al. Electrophysiological evaluation of peripheral and autonomic involvement in leprosy. Can J Neurol Sci 2004;(3):357-62.

[5] Goel UC, Gupta OP, Bajaj S, et al. Clinical profile and electrodiagnostic study of peripheral neuropathy. J Assoc Physicians India 1989;37(9):578-82.

[6] Brown TR, Kovinda A, Wathanadilokkol V, et al. Leprosy neuropathy: correlation of clinical and electrophysiological tests. Indian J Lepr 1996;68(1):114.

[7] Tzourio C, Henry P, Boucher P, et al. Lepromatous leprosy; clinical and electrophysiological arguments in favour of areonal multi neuritis. Acta Leprol 1989;7(1):51-6.

[8] Talwar S, Jha PK, Tiwari VD. Neuritic leprosy: epidemiological and therapeutic responsiveness. Lepr Rev 1992;63(3):263-8.

[9] Kumar B, Kaur I, Dogra S, et al. Pure neuritic leprosy in India: an appraisal. Int J Lepr Other Mycobact Dis 2004;72(3):284-90.

[10] Antia NH, Mehta L, Shetty V, et al. Clinical electro physiological, quantitative histologic and ultrastructural studies of the index branch of the radial cutaneous nerve in leprosy 1. Preliminary report. Int J Lepr 1975;43(2):106.

[11] Palande DD, Bowden RE. Early detection of damage to nerves in leprosy. Lepr Rev 1992;63(1):60-72.

G. Surya Narayana (1), C. Subhashini (2), B. Balachandrudu (3), S. Jahnavi (4), Ch. Naveen Kumar (5), Suneetha Patro (6), Divya (7), P. Guru Prasad (8)

(1) Assistant Professor, Department of DVL, Andhra Medical College, Visakhapatnam.

(2) Assistant Professor, Department of DVL, Andhra Medical College, Visakhapatnam.

(3) Professor & HOD, Department of DVL, Andhra Medical College, Visakhapatnam.

(4) Junior Resident, Department of DVL, Andhra Medical College, Visakhapatnam.

(5) Junior Resident, Department of DVL, Andhra Medical College, Visakhapatnam.

(6) Junior Resident, Department of DVL, Andhra Medical College, Visakhapatnam.

(7) Senior Resident, Department of DVL, Andhra Medical College, Visakhapatnam.

(8) Associate Professor, Department of DVL, Andhra Medical College, Visakhapatnam.

Financial or Other, Competing Interest: None.

Submission 15-12-2016, Peer Review 27-02-2017, Acceptance 04-03-2017, Published 13-03-2017.

Corresponding Author:

Dr. G. Surya Narayana, Assistant Professor, Department of DVL, KGH, Maharanipet, Visakhapatnam-523002.


DOI: 10.14260/jemds/2017/381
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Title Annotation:Original Research Article
Author:Narayana, G. Surya; Subhashini, C.; Balachandrudu, B.; Jahnavi, S.; Kumar, Ch. Naveen; Patro, Suneet
Publication:Journal of Evolution of Medical and Dental Sciences
Article Type:Report
Geographic Code:9INDI
Date:Mar 13, 2017
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