A prospective observational study was
conducted to assess the efficacy of SNRB in patients suffering from lumbar
radiculopathy due to disc prolapse, who did not respond to 6 weeks of
conservative management along with rehabilitation in virtue of Oswestry
Disability Index (ODI) and VAS score in the Indian population.
MATERIALS
AND METHODS
Inclusion
Criteria- Aged
20 to 60 years with lumbar radiculopathy with the herniated disc were selected
from the tertiary care hospital's outpatient department (spine clinic). They
were included in the study after fulfilment of inclusion criteria and informed
consent was obtained. These patients were diagnosed both clinically and
radiologically, having positive straight leg raising (SLR) test and a
lateralized disc herniation at the lumbar region shown in magnetic resonance
imaging (MRI).
Exclusion
Criteria- Patients
with the failed back syndrome, cauda equina syndrome, neoplastic or vascular
causes, pregnancy, or lactating mothers, extruded or sequestrated disc or
systemic diseases such as diabetes or any other source of infections were
excluded from the study.
50 Patients who fulfilled the inclusion
criteria were 30 males and 20 females. Pre-injection evaluation was done using
the visual analogue scale (VAS) and Oswestry disability index (ODI), which was
filled out by the patients and monitored in a chart.
A pre-procedure evaluation was done by
necessary investigations (CBC, ESR, CRP, Urine Routine and microscopy, Chest
X-ray in Anterior-Posterior view, Random blood Sugar) and vitals (Pulse rate,
Blood Pressure, Respiratory rate, Temperature.) were recorded to rule out any
source of infection or any co-morbidities.
Statistical Analysis- The data were
recorded using a Microsoft Excel Sheet and analysed
using the software SPSS version 2.0 and different tables/charts.
After
a thorough evaluation and intravenous infusion line assessment using 18G venflon, procedure was conducted
by an orthopaedic surgeon in the operation theatre
using fluoroscopy and Iopamidol non-ionic contrast
agent under aseptic condition (Fig. 1).
.jpg)
Fig. 1: Procedure of giving SNRB under C-Arm guidance
The
patient was asked to lie in a prone position. After proper drawing and
painting, the pathology site was identified using fluoroscopy in AP
(anterior-posterior) and lateral view (Fig. 2 & 3). After confirmation of
the pathological site, the skin and subcutaneous tissue were infiltrated with
local anaesthesia (2% lignocaine). The 22-gauge needle was inserted
transforaminal until the patient confirmed the pain along the affected site, Iopamidol radio-opaque dye (non ionic contrast agent) was
injected and the spread of the dye under fluoroscopy guidance was looked for
(Fig. 4, 5, 6) Needle position was confirmed under fluoroscopy guidance in
oblique view and the needle position was kept in the centre
of the eye of the scotty dog.
.jpg)
Fig. 4: C-Arm
image showing LS Spine lateral view with dye at nerve root
.jpg)
Fig. 6: C-Arm of
LS Spine AP view showing dye at bilateral nerve root)
Once
the position of the needle was confirmed, the mixture of the drug
(dexamethasone 8mg (2ml) + 2% lignocaine preservative-free (1ml) + normal
saline 2ml) was injected and the patient was asked about the reduction in pain
as compared to pre-injection. A positive selective nerve root block was defined
by Derby and Kine [12] as a reduction in
the degree of pain within 20 minutes of injection lasting for more than 30
minutes, which is considered positive. After the procedure, the patient was
shifted to the post-operative room for 2 hours and observed for any
complications. Evaluation was done clinically and neurologically by the VAS
score for pain and ODI score for disability. Any decrement in the VAS and ODI
was considered positive. Post-injection VAS score and ODI score were recorded
and monitored in the chart. After confirming the status of the patient and
vitals within normal parameters, patients were asked for discharge and advised
for sincere follow up to 1 year for VAS and ODI charting.
RESULTS-
In our study, lumbo-sacral radiculopathy
patients recorded mean age 38.8 10.15 years. Out of 50 patients, 30 patients
were male and 20 were female. The most common root involved were L4-L5 and
L5-S1 (Table 1).
Table
1: Demographic cycle
|
Age |
38.8 10.15 |
|
Gender |
Male (30), Female (20) |
|
L4-L5 |
23 |
|
L5-S1 |
27 |
|
Follow up period |
1 year |
The
pre-injection VAS Score of 7.46 1.02 was significantly reduced at follow-up 1
week (3.5 0.53, p<0.05), one month (3.44 0.49, p<0.05), three months
(3.34 0.71, p<0.05), 6 months (2.78 0.50, p<0.05) and 1 year (3.42 0.56,
p<0.05) (Table 1 & Fig. 7).
Table
2: Visual analogue pain score at different
follow-up periods
|
Time |
Mean S.
D |
p-value |
|
Pre-injection |
7.46
1.02 |
- |
|
1
week |
3.5 0.53 |
p<0.05 |
|
1
month |
3.44 0.49 |
p<0.05 |
|
3
months |
3.34 0.71 |
p<0.05 |
|
6
months |
2.78 0.50 |
p<0.05 |
|
1
year |
3.42 0.56 |
p<0.05 |
.png)
Fig.7: Pain Reduction at Different time Using VAS Score
Similarly, the pre-injection ODI score of 44.88 3.61
was also seen as a significant reduction at different follow-up periods of 1
week (26.6 2.84, p<0.05), 1 month (25.6 2.77, p<0.05), 3 months
(24.62 2.66, p<0.05), 6 months (23.66 2.51, p<0.05) and 1 year
(25.5 2.56, p<0.05) (Table 3; Fig. 8).
Table
3: Oswestry disability index score at
different follow-up period
|
Time |
Mean S.
D |
p-value |
|
Pre-injection |
44.88 3.61 |
- |
|
1
week |
26.6 2.84 |
p<0.05 |
|
1
month |
25.6 2.77 |
p<0.05 |
|
3
months |
24.62 2.66 |
p<0.05 |
|
6
months |
23.66 2.51 |
p<0.05 |
|
1
year |
25.5 2.56 |
p<0.05 |
.png)
Fig.
8: Disability
Reduction at Different Periods Using ODI Score
There
was no complication noticed during the procedure time.
DISCUSSION- Our orthopaedics
outpatient department routinely sees lumbar radiculopathy due to disc
prolapse/herniation. We encounter an increase in the number of patients with
lumbar radiculopathy who didn t respond to conservative management along with
rehabilitation and neither wanted to undergo surgery. This type of patient
requires something in between that can relieve their pain for a short duration
or delay the surgical procedure. Here, selective nerve root block plays an
important role in managing these patients regarding diagnostic and therapeutic
management. As the actual pathology of nerve root irritation is unknown, the
prognosis of these patients can vary.
Chronic
nerve root irritation in these patients causes radiculopathy and the ability to
facilitate or alleviate the pain forms the basis of selective nerve root block.
[13,14] Nowadays, MRI scan is the best diagnostic modality in spine
surgery compared to others in that field. However, the limitation is neither to
give a clear picture of all the causes of radiculopathy nor to correlate the
symptoms with its findings.[15] So, selective nerve root block is
becoming an easier and cheaper way to identify the root pain cause and
simultaneously administer a mixture of drugs as therapeutic injections to look
for pain relief, which is the aim of the selective nerve root block.
Patients
having severe disc herniation or prolapse who didn t want to undergo any
surgical procedure or didn t have any satisfactory reduction in pain except for
immediate post-procedure improvement. Through this, we can consider selective
nerve root block as a diagnostic procedure and confirm the site needs to
decompress. Similarly, patients having mild to moderate disc herniation or
prolapse show significant pain reduction but allow them to reconsider the next
line of management if the pain comes back.
Many
authors have used methylprednisolone-based preparations in the past for this
study; triamcinolone and betamethasone were also in demand. [16,17]
We chose a dexamethasone-based non-particulate solution for our study as it was
easily available in our institution. We have taken 8mg of steroid for SNRB for
satisfactory therapeutic effect. Utmost care was taken to handle the needle
gently to prevent any nerve injury, as most authors said this was to prevent
needle-based complications of root block. [18,19]
It
was seen that there was a significant reduction in the visual analogue score as
compared to pre-procedure values in 1st month as compared with the
other studies where the score was analysed at 6
weeks, 3 months and 1 year. [20,21] Comparatively, these studies
have shown a significant reduction with a statistical significance of
approximately 40-50% in the first 1 month. In contrast, Kappinen
has analyzed a 50% reduction in VAS score in the first 3 months (VAS
pre-injection 71 18, 3 months: 34.3).[20] Because of subjective
modalities like the VAS Score, slight differences can occur due to various
factors like pain perceptions and different races and populations.[22]
After 6 months of study, VAS score achieves a plateau phase with no significant
reduction in the Kappinen study, comparable with
ours.[20]Tafazzel also confirmed that
these findings have no benefits in assessing the visual analogue score in 12
12-month study.[21] However, the reduction seen in our study was
better even between 6 months and 1 year by using dexamethasone, which has a
shorter duration of action compared to their study as they have used
long-acting methyl-prednisolone.
Compared
to VAS score in our studies, ODI scores have a comparable pattern but a lesser
magnitude of reduction. Kappinen has shown that the
reduction in ODI score of his study was approximately 40-50 % in the first 3
months, which was not significant (ODI: pre-injection: 42.9 16) and not even at
6 months and 1 year respectively (18.9), and (15.9).[20] In the
Tafazal study, the ODI score was [ODI: pre-injection: 43.4 (32-54) Vs 6 weeks:
34.6 2.1; p=0.93], even less than kappinen.[21]A
systematic review of the studies shows no significant reduction in ODI score
compared to VAS Score with SNRB.[23] Our studies showed that ODI
parameters have no significant reduction after 6 months and 1 year of
follow-up.
The
patients who undergo this procedure can complain of painful procedures and will
face difficulty in cooperating, most commonly during the early phase of the
study.[24] However, we have excluded the cases that failed to comply
with the reduction in pain level during the early phase of the procedure. It
was noticed in the previous study that the furcal nerve and sinus-vertebral
nerve may get stimulated because of wrong needle placement.[25,26] So,
in our study, we used a non-ionic contrast medium for better accuracy and to
confirm the needle placement, we used fluoroscopy.
Previously,
some authors have suggested that the primary role of inflammation is to
increase the neural sensitivity of affected or irritated nerves.[27,28]
Since phospholipase A2 is the chief product of inflammation responsible for
lumbar radiculopathy and also the rate-limiting steps in the pathway of
arachidonic acid, many studies support similarity in pain score with the use of
dexamethasone, triamcinolone, and methylprednisolone in epidural injection.[26,29]
As triamcinolone aggregates into large particles, causing occlusion of
the major vessels and leading to ischaemic or
infarction, we used dexamethasone sodium phosphate, which is non-particulate.[30]
Complications
arising from SNRB are rare except for radicular spasm or cord infarction. The
most frequently reported side effects are insomnia, fever, face flushing, etc.
Other complications like increased blood glucose level, blood pressure, fluid
retention and hypothalamic-pituitary axis suppression have also been reported.
We didn t notice any adverse effects in our study, which may be due to the use
of dexamethasone.
This
study proves that selective nerve root block (SNRB) is effective in Indian
populations visiting a tertiary care hospital. Still, the outcome and accuracy
will be more validated in a large sample size.
The study recommends
selective nerve root block in patients with lumbar radiculopathy who didn t
respond to conservative management with physiotherapy for at least 6 weeks or
didn t want to undergo surgery due to financial issues. An added benefit of selective
nerve root block is that it can be utilised for both
therapeutic and diagnostic purposes.
Research concept- Gopal Kumar
Agarwal, Chirag Gupta
Research design- Kasinath Swain, Chirag Gupta
Supervision- Sandeep Lenka, Chirag Gupta, Manoj Kumar
Ram
Materials- Gopal Kumar
Agarwal, Sandeep Lenka,
Manoj Kumar Ram
Data collection- Gopal Kumar
Agarwal, Sandeep Lenka
Data analysis and Interpretation- Gopal Kumar
Agarwal, Chirag Gupta
Literature search- Gopal Kumar Agarwal Manoj
Kumar Ram
Writing article- Sandeep Lenka, Kasinath Swain, Diptiranjani Bisoyi
Critical review- Kasinath Swain,
Chirag Gupta, Diptiranjani Bisoyi
Article editing- Sandeep Lenka, Kasinath Swain, Manoj Kumar
Ram
Final approval- Sandeep Lenka, Diptiranjani Bisoyi
REFERENCES
1.
Lidgren L. The bone and joint decade 2000-2010.
Bull World Health Organ. 2003; 81(9): 629.
2.
Hoy D, Bain C, Williams
G, March L, Brooks P, et al. A systematic review of the global prevalence of
low back pain. Arthritis Rheum., 2012; 64: 2028 37.
3.
Meucci RD, Fassa AG,
Xavier Faria NM. Prevalence of chronic low back pain: systematic review. Rev Saud Publication,
2015; 49: 1 10.
4.
Gerrits MMJ, van Oppen P,
van Marwijk HWJ, Penninx
BWJH, et al. Pain and the onset of depressive and anxiety disorders. Pain,
2014; 155: 53 59.
5.
Kaiho Y, Sugawara Y, Sugiyama
K, Tomata Y, Endo Y, et al. Impact of pain on
incident risk of disability in elderly Japanese causespecific
analysis. Anesthesiol., 2018; 126: 688 96.
6.
Stubbs B, Binnekade T, Eggermont L, Sepehry AA, Patchay S, et al.
Pain and the risk for falls in community-dwelling older adults: systematic review and meta-analysis. Arch
Phys Med Rehabil., 2014; 95: 175 87.
7.
Riskowski JL. Associations of
socioeconomic position and pain prevalence in the United States: findings from the National Health and
nutrition examination survey. Pain Med., 2014; 15: 1508 21.
8.
Datta S, Manchikanti L,
Falco FJ, Calodney AK, Atluri S, et al. Diagnostic
utility of selective nerve root blocks in the diagnosis of lumbosacral
radicular pain: systematic review and update of current evidence. Pain
Physician. 2013; 16(2S): SE97-124.
9.
Thomas E, Cyteval C,
Abiad L, Picot MC, Taourel P, et al. Efficacy of
transforaminal versus interspinous corticosteroid injectionin
discal radiculalgia-a prospective, randomised, double-blind study. Clin Rheumatol.,
2003; 22(4-5): 299-304.
10. Beynon R, Elwenspoek MMC, Sheppard A, Higgins JN, Kolias AG, et al.
The utility of diagnostic selective nerve root blocks in the management of
patients with lumbar radiculopathy: a
systematic review. BMJ Open, 2019; 20; 9(4): e025790. doi:
10.1136/bmjopen-2018-025790.
11. Riew KD, Yin Y, Gilula L, Bridwell KH, Lenke LG, et al. The effect of
nerve-root injections on the need for operative treatment of lumbar radicular
pain. A prospective, randomized, controlled, double-blind study. J Bone Joint
Surg Am., 2000; 82(11): 1589-93.
12. Kolstad F, Leivseth G, Nygaard OP. Transforaminal steroid injections
in the treatment of cervical radiculopathy. A prospective outcome study. Acta Neurochir (Wien), 2005; 147(10): 1065-70.
13. Lin C, Darling C, Tsui
BCH. Practical Regional Anesthesia Guide for Elderly Patients. Drugs Aging,
2019; 36(3): 213-34.
14. Ju, M. S. et al.
Researches on biomechanical properties and models of peripheral nerves - a
review. J Biomechanical Sci Eng., 2017; 12: 16.
15. Svanbergsson
G, Ingvarsson T, Arnard ttir RH. MRI for diagnosis of low back pain: Usability, association with symptoms and
influence on treatment. Laeknabladid, 2017; 103(1):
17-22.
16. Mobaleghi J, Allahdini
F, Nasseri K, Ahsan B, Shami S, et al. Comparing the effects of epidural
methylprednisolone acetate injected in patients with pain due to lumbar spinal
stenosis or herniated disks: a
prospective study. Int J Gen Med., 2011; 4:
875-78.
17. Blankenbaker
DG, De Smet AA, Stanczak JD, Fine JP. Lumbar Radiculopathy: Treatment with Selective Lumbar Nerve
Blocks-Comparison of Effectiveness of Triamcinolone and Betamethasone
Injectable Suspensions. Radiol., 2005; 237: 738- 41.
18. Pfirrmann CW, Oberholzer PA,
Zanetti M, Boos N, Trudell DJ, et al. Selective nerve root blocks for the
treatment of sciatica: evaluation of
injection site and effectiveness--a study with patients and cadavers.
Radiology. 2001; 221(3): 704-11.
19. Slipman CW, Issac Z. The Role of
Diagnostic Selective Nerve Root Blocks in the Management of Spinal Pain. Pain
Physician 2001; 4: 214-26.
20. Karppinen J, Ohinmaa A, Malmivaara A, Kurunlahti M, Kyll nen E, et al. Cost effectiveness of periradicular infiltration for sciatica: subgroup analysis of a randomized controlled
trial. Spine (Phila Pa 1976). 2001; 26(23): 2587-95.
21. Tafazal S, Ng L,
Chaudhary N, Sell P. Corticosteroids in peri-radicular infiltration for
radicular pain: a randomised
double blind controlled trial. Oneyear results and
subgroup analysis. Eur Spine J., 2009; 18(8):
1220-25.
22. Jensen MP, Tom -Pires C,
de la Vega R, Gal n S, Sol E, et al. What Determines Whether a Pain is Rated
as Mild, Moderate, or Severe? The Importance of Pain Beliefs and Pain
Interference. Clin J Pain, 2017; 33(5): 414-21.
23. Quraishi NA.
Transforaminal injection of corticosteroids for lumbar radiculopathy: systematic review and meta-analysis. Eur Spine J., 2012; 21(2): 214-19.
24. Taguchi T, Kawai S,
Hashiguchi T. Reassessment of the diagnostic value of selective lumbosacral radiculography. J Neuroradiol.,
2002; 29(2): 122-27.
25. Uchikado H, Nishimura Y, Hattori
G, Ohara Y. Micro-anatomical structures of the lumbar intervertebral foramen
for full-endoscopic spine surgery:
review of the literatures. J Spine Surg., 2020; 6(2): 405-14.
26. Boada MD, Gutierrez S,
Aschenbrenner CA, Houle TT, Hayashida K, et al. Nerve injury induces a new
profile of tactile and mechanical nociceptor input from undamaged peripheral
afferents. J Neurophysiol., 2015; 113(1): 100-09.
27. Torun F, Mordeniz C, Baysal Z, Avci E, Togrul
T, et al. Intraoperative perineural infiltration of lidocaine for acute
post-laminectomy pain: pre-emptive
analgesia in spinal surgery. J Spinal Disord Tech.,
2010; 23(1): 43-46.
28. Dower A, Davies MA, Ghahreman A. Pathologic Basis of Lumbar Radicular Pain.
World Neurosurg., 2019; 128: 114-21.
29. Datta S, Everett CR, Trescot AM, Schultz DM, Adlaka R,
et al. An updated systematic review of the diagnostic utility of selective
nerve root blocks. Pain Phy., 2007; 10(1): 113-28.
30. Manchikanti L, Singh V, Cash KA, Pampati V,
Damron KS, et al. A randomized, controlled, double-blind trial of fluoroscopic
caudal epidural injections in the treatment of lumbar disc herniation and
radiculitis. Spine (Phila Pa 1976), 2011; 36(23): 1897-905.