Dear Editor,
Leprosy is a chronic infectious disease with a disabling potential due to the affinity
of the agent, Mycobacterium leprae, for peripheral nerves and skin. Of the 208,619
new cases detected worldwide in 2018, a total of 11,323 cases already had apparent
deformities, of which 2,109 (18.6%) were from Brazil, a figure that was second only
to India, with 3,666 new cases with deformities.
1
Neuropathy in leprosy can occur insidiously, more commonly as multiple mononeuropathy,
with the simultaneous involvement of two or more peripheral nerves in different regions
of the body, with the ulnar and posterior tibial nerves being the most frequently
affected. Neural damage can also often occur during acute episodes of immunological
reactions against bacillary antigens that may occur during the course of the disease
or even after polychemotherapeutic treatment, in the form of neuritis with edema,
vascular obstruction, ischemia, and strangulation in the passage through the osteofibrous
channels of the limbs, leading to pain and deficit of function, the main cause of
physical disabilities and stigma of the disease.2, 3
The basis for neuritis treatment is prednisone, used to control the inflammatory process
and pain, preventing permanent neural damage. Neurolysis is surgery for nerve decompression
through an incision in the epineurium and opening of the osteofibrous canal to release
the nerve, at the level of the elbow and/or wrist.
3
It is performed mainly in cases of nerve abscess, neuritis not responsive to clinical
treatment for four weeks, recurrent or subentrant episodes of neuritis, chronic neuritis
with deficit and pain, and neuritis in patients with comorbidities that contraindicate
the use of corticosteroids aiming to decrease the dose and in cases of corticosteroid
contraindications.
4
With the purpose of describing the clinical evolution of neural function and neuritis
recurrences of leprosy patients with neuritis submitted to neurolysis, we present
a series of 22 cases of ulnar nerve surgery performed in the years 2015 and 2016,
at Fundação de Dermatologia Tropical e Venereologia Alfredo da Matta, located in the
state of Amazonas, in the city of Manaus, Brazil.
Immediately before the neurolysis and after it (30, 90 days and according to the follow-up),
the Simplified Neurological Assessment was carried out according to the protocol of
the Ministry of Health of Brazil.
4
Sensibility evaluation was performed with an esthesiometer or Semmes-Weinstein monofilament,
which consists in a set of six nylon threads of different colors and thicknesses that,
pressed against the skin, correspond to different weights (from 0.05 g to 300 g).
The 0.05 g (green) and 0.2 g (blue) monofilaments were considered as normal sensibility
and above that, as decreased sensibility.
5
For the assessment of muscle strength, the abductor muscle of the fifth finger was
assessed and the Medical Research Council scale was used, which ranks strength from
zero (no muscle movement) to five (complete movement against gravity with maximum
resistance).
4
Levels four (full movement against gravity with partial resistance) and five were
considered normal.
5
The time between the first episode of neuritis and the performance of neurolysis was,
on average, 25.3 months (SD = 63.3; Min. = 1; Max. = 303), with the procedure being
performed after up to six months in 11 (50.0%) patients, which is related to the best
results by other authors.
5
For comparison purposes, the last neurological evaluation was considered in the present
study, which ranged from three to 168 months, with 12 (54.5%) patients having more
than one year of follow-up.
Of 12 cases that already had altered sensibility before surgery, seven (58.3%) showed
improvement and, of the six that had altered muscle strength, five (83.3%) maintained
the same level, and only one (16.7% ) showed worsening. Fifteen (68.2%) patients did
not have any neuritis in the operated nerve; however, three of these patients still
had to use prednisone, because they had a leprosy reaction and/or neuritis in other
nerves. Two patients had only a single episode of neuritis, which occurred three and
four months after surgery. Another five patients (18.2%) had subentrant episodes of
neuritis in the operated nerve, for an average of 52.6 months (SD = 63; Min. = 17;
Max. = 172) after surgery, without necessarily developing loss of function (Table
1).
Table 1
Characteristics of leprosy cases submitted to ulnar neurolysis.
Table 1
Numerical order
Sex
Age at diagnosis (years)
Clinical form
Time in months between
Sensibilitya
Muscle strengthb
Time with recurrences (months)
Neuritis and neurolysis
Neurolysis and evaluation
Initial
Final
Initial
Final
1
M
31
BL
01
03
0.05 g
0.05 g
4
5
–
2
M
22
BL
02
20
0
10 g
4
5
21
3
M
34
LL
02
05
0.05 g
0.2 g
5
5
–
4
M
8
TT
02
44
300 g
10 g
0
0
–
5
M
20
BT
02
08
300 g
0
0
0
–
6
M
26
BL
02
18
0.05 g
300 g
5
4
03c
7
M
13
BT
03
34
300 g
300 g
4
5
–
8
M
35
LL
04
14
0.2 g
0.2 g
5
5
–
9
M
39
LL
04
30
0
4g
3
3
–
10
M
49
LL
05
24
0.2 g
0.2 g
5
5
–
11
M
51
BL
6
03
300 g
0
2
2
–
12
M
24
LL
09
26
300 g
0.2 g
5
5
–
13
M
24
LL
10
02
0.2 g
0.2 g
5
5
–
14
M
11
BL
12
21
0.05 g
0.05 g
5
5
21
15
M
36
BL
16
17
300 g
10 g
3
3
17
16
M
15
LL
17
04
0.05 g
0.05 g
5
5
–
17
F
57
BT
20
08
300 g
0.2 g
4
4
–
18
M
18
BL
20
168
300 g
0
3
1
172
19
M
17
LL
31
10
0.05 g
0.2 g
5
5
32
20
F
12
BT
36
04
300 g
4g
4
5
04c
21
M
19
BL
49
135
0.05 g
0.05 g
5
5
–
22d
M
26
LL
303
03
10 g
10 g
2
2
–
a
Monofilament: 0.05 g (green) and 0.2 g (blue) = normal sensibility; 2.0 g (violet) = decrease
in protective sensibility, with decreased discrimination of shape and temperature;
4.0 g (dark red) = decreased protective sensibility; 10.0 g (orange) = can feel deep
pressure and pain; 300.0 g (magenta red) = loss of deep pressure feeling, can feel
pain; and 0 = does not feel any monofilament or absence of sensibility to pressure
or pain.
b
Medical Research Council scale.
c
Month of occurrence of the single episode of neuritis.
d
This patient had a recurrence.
This series of cases emphasizes the clinical importance of the results in a routine
situation, where the greatest contribution of neurolysis associated with the clinical
treatment of leprosy neuritis was the non-recurrence or non-chronicity of the condition.
Neurolysis also prevents prolonged corticosteroid therapy and its consequences, in
addition to the possible evolution into physical disabilities. There was sensory function
gain in most of the assessed cases. However, it is necessary to carry out studies
with appropriate methodology to evaluate the effectiveness of neurolysis or its benefits
in comparison to clinical treatment alone, even considering the studies that have
been published for decades.
5
Financial support
10.13039/501100004916
Fundação de Amparo à Pesquisa do Estado do Amazonas
- undergraduate scholarship.
Authors’ contributions
Juliana Barroso-Freitas: Design and planning of the study; drafting and editing of
the manuscript; collection, analysis, and interpretation of data; critical review
of the literature.
Pedro Arthur da Rocha Ribas: Critical review of the literature; collection, analysis,
and interpretation of data.
Paula Frassinetti Bessa Rebello: Design and planning of the study; critical review
of the literature; analysis of data; critical review of the manuscript.
Silmara Navarro-Pennini: Design and planning of the study; drafting and editing of
the manuscript; critical review of the literature; analysis of data.
Conflicts of interest
None declared.