LL patients might present alterations in medium and large caliber fibers at diagnosis independent of neural clinical signs.
Table 2 describes the demographic and clinical characteristics of patients recruited for this study at the beginning of MDT and by the time of biopsy. The time between beginning MDT and biopsy ranged from 4 to 16 years (mean 8.14 years). Ten patients were male (71.4%), with ages ranging from 19 to 46 years (mean age 32.38 years) at the beginning of treatment, and ranging from 31 to 61 years (mean age 40.9 years) by the time of biopsy. According to the WHO grading system, 46.1% of patients were included as grade 0 (n=6). At the evaluation at the time of the nerve biopsy most patients were classified as grade 1 (46.1%). The average bacilloscopic index (BI) at the beginning of treatment was 3.95 (2.16 - 4.83) and dropped significantly to an average of 1.0 (0 - 2.85) at the time of the biopsy, confirmed by Mann Whitney test (p = 0.003).
Table 2
Demographic and Clinical characteristics of recruited patients at the beginning of MDT
Demographic Characteristics
|
At the beginning of MB treatment
|
At the time of biopsy (neural damage)
|
Age - years mean (min-max)
|
32.38 (19-46)
|
40.9 (31-61)
|
Gender
|
|
|
Male
|
10 (71.4%)
|
10 (71.4%)
|
Female
|
4 (28.6%)
|
4 (28.6%)
|
Disability grade
|
|
|
0
|
6 (46.1%)
|
5 (38.5%)
|
1
|
4 (30.8%)
|
6 (46.1%)
|
2
|
3 (23.1%)
|
2 (15.4%)
|
bacilloscopic index mean (min-max)
|
3.95 (2.16-4.83)
|
1.00 (0-2.25)
|
Time between beginning MDT and worsening of neural damage in years (min-max)
|
8.14 (4-16)
|
Clinical Characteristics
|
|
|
Symptoms (peripheral nerve related)
|
|
|
No symptoms
|
4 (28.6%)
|
0 (0%)
|
Pain
|
1 (7.1%)
|
9 (64.3%)
|
Paresthesia
|
6 (42.9%)
|
9 (64.3%)
|
Numbness
|
4 (28.6%)
|
1 (7.1%)
|
Signs (peripheral nerve related)
|
|
|
No signs
|
1 (7.1%)
|
0 (0%)
|
Painful and/or thermal impairment
|
2 (14.3%)
|
1 (7.7%)
|
Tactile impairment
|
6 (42.9%)
|
5 (35.7%)
|
Motor
|
3 (21.4%)
|
5 (35.7%)
|
Missing info
|
2 (14.3%)
|
3 (23.1%)
|
Thickening
|
|
|
Yes
|
9 (64.3%)
|
8 (57.1%)
|
No
|
4 (28.6%)
|
4 (28.6%)
|
Missing info
|
1 (7.1%)
|
2 (14.3%)
|
Symptoms at the beginning of treatment were compared with those at the time of the biopsy using the Mcnemar test and only pain showed a significant difference (p = 0.006). Paresthesia and numbness did not show significant differences (p = 0.102 and p = 0.371, respectively). In relation to the signs of involvement of the peripheral nerve, we were only able to evaluate thickening by the Mcnemar test, which showed no significant difference (p = 0.317). Neurological examination showed that the majority of patients already had alterations in medium and large caliber fibers since the beginning of the treatment (64.3%), which increased to 71.4% of patients at the time of biopsy (Table 2).
Table 3 describes signs and symptoms of each patient at the beginning of MDT and at the time of the biopsy, as well as the time of MDT and the amount of prednisone and thalidomide to treat the reactions and neuritis that the patients had during the entire follow-up period.
Table 3
– Comparison of signs, symptoms and treatment of each patient at the beginning of MDT and by the time of biopsy
Neurological Evaluation at the beginning of MDT
|
|
|
Patient
|
Gender
|
Age
|
Pain
|
Parest
|
Tact NFI
|
Therm NFI
|
Painf NFI
|
Mot NFI
|
MDT (Mon)
|
Tim B-B (y)
|
AJR
|
MALE
|
45
|
NO
|
NO
|
YES
|
NO INFO
|
NO INFO
|
NO INFO
|
24
|
7
|
ALCF
|
MALE
|
25
|
NO
|
YES
|
NO
|
YES
|
YES
|
NO
|
24
|
11
|
NMC
|
MALE
|
28
|
NO
|
YES
|
YES
|
YES
|
YES
|
NO
|
24
|
4
|
ALRS
|
MALE
|
19
|
NO
|
NO
|
YES
|
YES
|
YES
|
NO
|
24
|
12
|
NMS
|
MALE
|
45
|
NO
|
YES
|
YES
|
YES
|
YES
|
YES
|
12
|
16
|
LGPA
|
MALE
|
23
|
NO
|
YES
|
YES
|
YES
|
YES
|
NO
|
12
|
9
|
RJRF
|
MALE
|
46
|
NO
|
YES
|
YES
|
NO
|
YES
|
NO INFO
|
12
|
8
|
CDO
|
MALE
|
31
|
NO
|
NO
|
YES
|
YES
|
YES
|
YES
|
12
|
6
|
SFV
|
FEMALE
|
35
|
YES
|
YES
|
YES
|
YES
|
YES
|
NO
|
12
|
8
|
MAP
|
FEMALE
|
31
|
NO
|
NO
|
YES
|
YES
|
YES
|
NO
|
12
|
8
|
MVR
|
FEMALE
|
41
|
NO
|
NO
|
NO
|
YES
|
NO
|
NO
|
12
|
4
|
VST
|
MALE
|
28
|
NO
|
NO
|
YES
|
YES
|
YES
|
YES
|
12
|
7
|
ASA
|
MALE
|
31
|
NO
|
NO
|
NO
|
NO
|
NO
|
NO
|
12
|
6
|
APAF
|
FEMALE
|
34
|
NO
|
NO
|
YES
|
YES
|
YES
|
NO
|
12
|
8
|
Neurological Evaluation by the time of biopsy
|
|
|
Patient
|
Age
|
Pain
|
Parest
|
Tact NFI
|
Therm NFI
|
Painf NFI
|
Mot NFI
|
PDN (mg)
|
TLD (mg)
|
|
AJR
|
52
|
YES
|
YES
|
YES
|
NO INFO
|
NO INFO
|
NO INFO
|
6249
|
18000
|
|
ALCF
|
36
|
YES
|
YES
|
NO
|
YES
|
YES
|
NO
|
2315
|
NO
|
|
NMC
|
33
|
YES
|
YES
|
YES
|
YES
|
YES
|
NO
|
44030
|
29200
|
|
ALRS
|
31
|
NO
|
YES
|
YES
|
YES
|
YES
|
NO
|
24265
|
NO
|
|
NMS
|
61
|
YES
|
YES
|
YES
|
YES
|
YES
|
YES
|
19490
|
142600
|
|
LGPA
|
32
|
YES
|
YES
|
NO
|
NO
|
YES
|
NO
|
20190
|
259400
|
|
RJRF
|
54
|
YES
|
YES
|
YES
|
YES
|
YES
|
YES
|
27165
|
210736
|
|
CDO
|
37
|
NO
|
NO
|
YES
|
YES
|
YES
|
YES
|
9015
|
73100
|
|
SFV
|
43
|
YES
|
NO INFO
|
NO INFO
|
NO INFO
|
NO INFO
|
NO INFO
|
57555
|
4500
|
|
MAP
|
39
|
YES
|
NO
|
YES
|
YES
|
YES
|
NO
|
24865
|
145500
|
|
MVR
|
45
|
NO
|
YES
|
YES
|
YES
|
YES
|
NO
|
NO INFO
|
NO INFO
|
|
VST
|
35
|
YES
|
YES
|
YES
|
YES
|
YES
|
YES
|
7600
|
297400
|
|
ASA
|
37
|
YES
|
YES
|
YES
|
YES
|
YES
|
YES
|
39740
|
297400
|
|
APAF
|
42
|
NO
|
NO
|
YES
|
YES
|
YES
|
NO INFO
|
32580
|
25500
|
|
Parest – paresthesia; Tact NFI – Tactile nerve function impairment; Therm NFI – thermal nerve function impairment Painf NFI – painful nerve function impairment; Mot NFI – motor nerve function impairment; MDT (Mon) – time of MDT in months; PDN (mg) – total dose of prednisone until biopsy in miligrams; TLD (mg) - total dose of thalidomide until biopsy in miligrams; TIM B-B (y) – time between beginning of leprosy treatment and biopsy; NO INFO – no information
|
Nerve Conduction Studies (NCS) demonstrate that sensory nerves were the most affected in LL patients.
All patients were submitted to NCS by the time of biopsy, but only 8 out of the 14 patients underwent NCS at some point during the follow-up, not necessarily at the beginning of treatment, but years before the biopsy. The other 6 were submitted to NCS just before the biopsy.
Table 4 compares the average values of the first NCS performed years before the biopsy with those at the time of the biopsy by nerve studied.
There was significant worsening of sensory amplitude and sensory conduction velocity values, by the time of biopsy than in previous years, as well as an increase in the percentage of abnormal exams.
Table 4
– Mean values of NCS and percentage of abnormality
Electrophysiological function
|
Normal Value
|
First NCS (n=16)
|
Pre biopsy NCS (n=28)
|
|
Motor Function
|
|
Mean
|
Range
|
% abnormal
|
Mean
|
Range
|
% abnormal
|
P value
|
Ulnar Nerve
|
|
|
|
|
|
|
|
|
Distal Latency (ms)
|
<3.2
|
2,9
|
2.5-3.5
|
22%
|
3.3
|
2.1-6.5
|
39.3%
|
0.88
|
NCV (m/s)
|
>55.0
|
55.6
|
47-60.4
|
43.75%
|
53.8
|
20.8-65.5
|
53.6%
|
0.55
|
Amplitude (mV)
|
>4.0
|
5.9
|
0.35-11.2
|
12.5%
|
5.1
|
0.29-9.44
|
32.1%
|
0.24
|
Median Nerve
|
|
|
|
|
|
|
|
|
Distal Latency (ms)
|
<3.7
|
3.9
|
3.1-5.6
|
40%
|
3.7
|
3.8-5.4
|
39.3%
|
0.39
|
NCV (m/s)
|
>52.0
|
53.9
|
48-61.9
|
31.2%
|
52.5
|
43.3-66.5
|
53.6%
|
0.48
|
Amplitude (mV)
|
>4.0
|
5.5
|
2.1-10.1
|
25%
|
7.3
|
0.39-13.5
|
14.3%
|
0.026
|
Common peroneal nerve
|
|
|
|
|
|
|
|
|
Distal Latency (ms)
|
<4.5
|
3.7
|
0-5.9
|
40%
|
3.9
|
0-9.4
|
20.8%
|
0.31
|
NCV (m/s)
|
>42.0
|
43.5
|
0-60
|
25%
|
37.8
|
0-55.3
|
50%
|
0.22
|
Amplitude (mV)
|
>2.0
|
3.3
|
0-5.9
|
18.7%
|
2.7
|
0-9.4
|
45.9
|
0.06
|
Tibial Nerve
|
|
|
|
|
|
|
|
|
Distal Latency (ms)
|
<4.5
|
NR
|
NR
|
NR
|
4.6
|
0-6.25
|
58.8
|
NR
|
NCV (m/s)
|
>43.0
|
NR
|
NR
|
NR
|
NR
|
NR
|
NR
|
NR
|
Amplitude (mV)
|
>4.0
|
NR
|
NR
|
NR
|
5.3
|
0.18-14.8
|
43.7%
|
NR
|
Sensory Function
|
|
|
|
|
|
|
|
|
Ulnar Nerve
|
|
|
|
|
|
|
|
|
Latency (ms)
|
<2.6
|
1.84
|
0-2.78
|
20%
|
0.7
|
0-2.7
|
78.6%
|
0.89
|
NCV (m/s)
|
>43.0
|
41.6
|
0-56.6
|
37.5%
|
14.0
|
0-60.6
|
75%
|
0.002
|
Amplitude (µV)
|
>8.0
|
11.2
|
0-21.7
|
31.2%
|
2.6
|
0-16.6
|
85.7%
|
0.001
|
Median Nerve
|
|
|
|
|
|
|
|
|
Latency (ms)
|
<3.4
|
2.1
|
0-2.9
|
20%
|
1.7
|
0-3.8
|
50%
|
0.91
|
NCV (m/s)
|
>42.0
|
44.4
|
0-61.2
|
25%
|
26.9
|
0-57.9
|
50%
|
0.006
|
Amplitude (µV)
|
>15.0
|
18.2
|
0-42.7
|
43.7%
|
6.4
|
0-26.9
|
85.7%
|
0.001
|
Radial Nerve
|
|
|
|
|
|
|
|
|
Latency (ms)
|
<2.4
|
1.2
|
0-2.4
|
30%
|
1.2
|
0-3.02
|
71.4%
|
0.91
|
NCV (m/s)
|
>41.0
|
35.9
|
0-61.7
|
37.5%
|
21.7
|
0-52.6
|
67.8%
|
0.002
|
Amplitude (µV)
|
>8.0
|
9.3
|
0-18.3
|
25%
|
4.85
|
0-19.2
|
67.8%
|
0.005
|
Sural Nerve
|
|
|
|
|
|
|
|
|
Latency (ms)
|
<3.5
|
0
|
0
|
100%
|
0.41
|
0-3.3
|
85.7%
|
0.18
|
NCV (m/s)
|
>38.0
|
0
|
0
|
100%
|
6.9
|
0-56.2
|
85.7%
|
0.18
|
Amplitude (µV)
|
>7.0
|
0
|
0
|
100%
|
0.9
|
0-17.1
|
92.8%
|
0.18
|
Superficial peroneal Nerve
|
|
|
|
|
|
|
|
|
Latency (ms)
|
<3.5
|
NR
|
NR
|
NR
|
0
|
0
|
100%
|
NR
|
NCV (m/s)
|
>38.0
|
NR
|
NR
|
NR
|
0
|
0
|
100%
|
NR
|
Amplitude (µV)
|
>5.0
|
NR
|
NR
|
NR
|
0
|
0
|
100%
|
NR
|
NCS = nerve conduction study; NR = not realized; ms (miliseconds); mV – millivolt; µV = microvolt; m/s = meter per second; n = number of nerves
|
Table 5compares the clinical data from the beginning of treatment of the 14 patients and the first NCS of 8 patients who had had years before the biopsy with the clinical and NCS data before the biopsy of the 14 patients. Clinical and electrophysiological worsening of the total number of affected nerves was observed, even though the data for years before the biopsy is not available for all patients.
Table 5
Clinical eletrophysiological comparison of each altered nerve years before and by the time of biopsy
|
Clinical impairment
|
|
NCS
|
|
Nerve
|
|
|
|
|
|
|
|
First evaluation
|
|
|
|
|
|
|
|
Sensory
|
T/P
|
Tactile
|
MI
|
|
sNCS
|
MI
|
|
Median
|
7/26 (26%)
|
6/28 (21.4%)
|
2/28
|
|
9/16 (56.2%)
|
12/28
|
|
Radial
|
7/26 (26%)
|
7/28 (25%)
|
2/28
|
|
4/16 (25%)
|
12/28
|
|
Ulnar
|
9/26 (34.6%)
|
8/28 (28.6%)
|
2/28
|
|
9/16 (56.2%)
|
12/28
|
|
Sural
|
20/26 (76.9%)
|
18/28 (64.3%)
|
2/28
|
|
16/16 (100%)
|
12/28
|
|
Superficial peroneal
|
17/26 (65.4%)
|
11/28 (39.3%)
|
2/28
|
|
2/2 (100%)
|
26/28
|
|
Motor
|
|
|
VMT
|
MI
|
|
mNCS
|
MI
|
Median
|
|
|
0/24 (0%)
|
0
|
|
6/16 (37.5%)
|
12/28
|
Ulnar
|
|
|
3/24 (12.5%
|
0
|
|
12/16 (75%)
|
12/28
|
Common peroneal
|
|
|
4/24 (16.6%)
|
0
|
|
7/16 (43.7%)
|
12/28
|
Tibial
|
|
|
2/24 (8.3%)
|
0
|
|
0/2 (0%)
|
26/28
|
By the time of biopsy
|
|
|
|
|
|
|
|
Sensory
|
T/P
|
Tactile
|
MI
|
|
sNCS
|
MI
|
|
Median
|
12/24 (50%)
|
9/26 (34.6%)
|
4/28
|
|
24/28 (85.7%)
|
0/28
|
|
Radial
|
11/24 (45.8%)
|
8/26 (30.8%)
|
4/28
|
|
20/28 (71.4%)
|
0/28
|
|
Ulnar
|
17/24 (70.8%)
|
9/26 (34.6%)
|
4/28
|
|
23/28 (82.1%)
|
0/28
|
|
Sural
|
22/24 (91.6%)
|
20/26 (76.9%)
|
4/28
|
|
26/28 (92.5%)
|
0/28
|
|
Superficial peroneal
|
21/24 (87.5%)
|
18/26 (69.2%)
|
4/28
|
|
18/18 (100%)
|
0/28
|
|
Motor
|
|
|
VMT
|
MI
|
|
mNCS
|
|
Median
|
|
|
0/22 (0%)
|
6/28
|
|
19/28 (67.8%)
|
0/14
|
Ulnar
|
|
|
6/22 (27.3%)
|
6/28
|
|
23/28 (82.1%)
|
0/14
|
Common peroneal
|
|
|
4/22 (18.2%)
|
6/28
|
|
17/28 (60.7%)
|
0/14
|
Tibial
|
|
|
0/22 (0%)
|
6/28
|
|
8/16 (50%)
|
12/28
|
MI = Missing information; T/P = Thermal and Painful sensitivity; VMT = Voluntary Motor test; sNCS = sensory NCS; mNCS = motor NCS
|
LL patients presented worsened neurological symptoms irrespective of the use of prednisone or thalidomide.
In the period between the beginning of the treatment and the nerve biopsy, patients were followed up and treatment of leprosy and reactions were evaluated. During all the years of follow-up, during and after the end of MDT, patients used corticosteroids and / or thalidomide to treat neuropathic pain, which was refractory to the withdrawal of these medications. They had received a total dosage of 315.31 grams, with an average of 24.25 grams of prednisone (2.32 to 44.03 grams) and a total dosage of 1352.34 grams, with an average of 104.02 grams of thalidomide (0 to 297.4 grams) (Figure 1). During this time, patients were treated as if they had chronic neuritis, but there was a worsening of symptoms despite treatment or only a relief of symptoms that worsened following the attempt to withdraw medication. Deterioration of electrophysiological findings was also found, and, therefore, nerve biopsy was indicated for better evaluation of the condition.
All patients had inflammatory infiltrate and 13 (92.9%) of them were positive for acid-fast bacilli. Eleven (78.57%) patients were submitted to a new cycle of MDT treatment since they presented clinical and neurophysiological worsening and were unresponsiveness to corticosteroids.