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Reappraisal of microsurgical decompression and neurectomy of the occipital nerve in the treatment of occipital neuralgia
Accepted Manuscript Reappraisal of microsurgical decompression and neurectomy of the occipital nerve in the treatment of occipital neuralgia
Ulises García, Juan Del Castillo-Calcáneo, María Elena CordobaMosqueda PII: DOI: Reference:
S2214-7519(17)30157-3 doi: 10.1016/j.inat.2017.07.011 INAT 231
To appear in:
Interdisciplinary Neurosurgery: Advanced Techniques and Case Management
Received date: Revised date: Accepted date:
4 July 2017 11 July 2017 16 July 2017
Please cite this article as: Ulises García, Juan Del Castillo-Calcáneo, María Elena Cordoba-Mosqueda , Reappraisal of microsurgical decompression and neurectomy of the occipital nerve in the treatment of occipital neuralgia, Interdisciplinary Neurosurgery: Advanced Techniques and Case Management (2017), doi: 10.1016/j.inat.2017.07.011
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Reappraisal of Microsurgical Decompression and Neurectomy of the Occipital Nerve in the treatment of Occipital Neuralgia
Ɨ
1. 2.
Ɨ
Neurosurgery Department, Mexican Oil Company (Pemex) High Specialty Hospital, Mexico City, Mexico Neurosurgery, National Autonomous University of Mexico, Mexico City, Mexico
Ɨ
PT
Type of article:
SC
RI
Disclosures
AC
CE
PT E
D
MA
NU
Corresponding author:
1. Introduction
Occipital neuralgia is defined by the international headache society (IHS) as a unilateral or bilateral paroxysmal, shooting or stabbing pain in the posterior part of the scalp, in the distribution of the greater and lesser occipital nerves, sometimes accompanied by diminished sensation or dysaesthesia in the affected area and commonly associated with tenderness over
ACCEPTED MANUSCRIPT the involved nerve(s).1 This pain usually originates in the suboccipital region and irradiates to the vertex. There is no definitive data about the prevalence or incidence of occipital neuralgia, there is a dutch study which reported a low incidence of 3.2 per 100,000.2 however this is the only study that exists to date and is thought to be an underdiagnosed entity due to the number of
PT
differential diagnosis that are possible.
RI
Many etiologies of occipital neuralgia have been reported in the literature, however the most
SC
common one is of compressive origin either by trauma which causes subsequent fibrosis or by
NU
muscle contraction.3
There are currently various accepted treatment methods reported in the literature, ranging
MA
from medical treatment using neuropathic agents such as antiepileptic and/or antidepressant medications which is considered as the first line of treatment, local injections to the nerve
D
using local anesthetics combined with steroids are also considered a treatment as well as a
PT E
diagnostic test, lately nerve stimulation has been given much attention and even a systematic review and evidence-based guideline was published about this method concluding that it has
AC
CE
a level III recommendation strength. 4
Neurolysis of the occipital nerve (with or without sectioning of the inferior oblique muscle), C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, and
ACCEPTED MANUSCRIPT neurectomy were historically introduced for medically re-fractory patients.
5-9
But ultimately
have lost its place in favor of nerve stimulation. Our aim in this study is to report our experience and treatment algorithm with our modified neurectomy surgical technique which provides excellent results in pain control for patients who suffer occipital neuralgia and that can be considered as a safe alternative when
RI
2. Methods
PT
neurostimulation and radiofrequency are not available.
SC
We performed a retrospective chart review of all 26 subjects diagnosed with Occipital
NU
Neuralgia from January 2014 when our treatment algorithm started to be used in our institution and obtained an 18 subjects case series with follow ups of 6 months who
MA
underwent our treatment algorithm for Occipital Neuralgia.
D
2.1. Patient selection
PT E
Starting in January 2014 all patients that were diagnosed with occipital neuralgia under the IHS classification comprising the next clinical features (Table 1) were enrolled to our
CE
algorithm for occipital neuralgia treatment. (Figure 1)
AC
2.2. Treatment Algorithm After being diagnosed clinically as occipital neuralgia, all patients underwent the treatment algorithm, in which as a mean of confirmation of the neuralgia and as a treatment method they were offered a local injection with ropivacaine and dexamethasone, patients were required to sign an informed consent in order to obtain the injection, if they refused they were treated medically only with option to receive the injection if they ultimately decided to sign the consent.
ACCEPTED MANUSCRIPT 26 patients were identified with occipital neuralgia, all patients signed the consent and underwent the local injection first and 22 underwent microsurgical decompression and neurectomy, however we reduced our case series to 18 due to incomplete follow-up in 4 cases. All cases received evaluation using the Barrow Neurological Institute Pain Score (BNIPS)
PT
(Table 2) in order to evaluate the pain frequency and control as well as the Visual Analogue
RI
Scale (VAS) to evaluate pain intensity and clinical evaluation of sensitivity in the C2
SC
dermatome.
NU
2.3. Local Injection
Once the side and affected nerves were identified, we injected either 1 or 2 points (this
MA
depended on the number of nerves affected, if it was only the GON, LON or both) in accordance to the Vital and Becser10 previously reported technique, we used for injection a
PT E
we injected 10ml. (Figure 2)
D
combination of ropivacaine 7.5% and dexamethasone 8mg titered at 1:1 ratio, for each point
After local injection patients were immediately discharged and came back for evaluation at 6
CE
weeks, if the improvement on VAS and BNIPS was more than 50% then the patient was deemed as a good candidate for surgical decompression and neurectomy of the affected nerve
AC
and the surgery was offered, out of the 26 subjects, 22 accepted the surgical treatment immediately, the other 4 presented reduction in pain less than 50% and entered the algorithm for reevaluation and medical treatment and are currently being followed.
2.4. Surgical procedure 2.4.1. Patient Positioning The subjects were placed in a prone position with the head resting on a horseshoe adapter for the mayfield headrest with a 45 degree flexion of the neck to provide better exposure of the
ACCEPTED MANUSCRIPT cervical spinous processes and the inion to locate the superficial landmarks, the thorax is placed over two gel rolls and all of the pressure points are padded. (Figure 3) 2.4.2. Incision Planning and superficial landmarks Incision was planned according to the affected side and nerves, if the neurolysis was going to be of the GON a linear 3cm incision was made cm from the midline at the level of the inion,
PT
extending 1.5cm superior and 1.5cm inferior. If the LON was the affected nerve then the
RI
incision would be made cm from the midline, if both nerves were affected then the incision
SC
would be made at the midpoint of this two markings. (Figure 4) 2.4.3. Microsurgical Decompression and Neurectomy.
NU
The incision was performed using an 11 blade and careful blunt dissection through the
MA
subcutaneous plane is made with metzenbaum scissors approximately 1cm to each side until the nerve is identified, for faster identification of the nerve we suggest using the occipital
D
artery pulsations since in this portion of the nerve the artery is adjacent to it, then the nerve
PT E
trajectory is followed while performing its decompression from the P2 portion at the exit point in the nuchal line to 3cm distal to the exit point, the proximal end of the nerve is ligated
CE
using 2-0 chromic catgut to avoid formation of neuromas and the nerve is excised completely along with the fibrosis surrounding it and sent to pathology.
AC
2.4.4. Closure.
After decompression and neurectomy had been achieved, hemostasis was ensured with bipolar coagulation and a two-stage closure performed, closing the galea and subcutaneous tissue with interrupted inverted 2-0 vicryl, the superficial skin was closed using a subcutaneous continuous suture with 3-0 monocryl.
ACCEPTED MANUSCRIPT 2.5. Post-Surgery Follow Up All patients remained hospitalized for 24 hours after surgical decompression for pain evaluation. Subjects were evaluated using the VAS and BNIPS at the immediate postoperative time (24 hours) as well as 3 and 6 months postoperatively. Sensitivity in the C2 area was also evaluated.
PT
2.6. Statistical Analysis
RI
Median and standard deviations were used to describe the population of the study as well as
SC
the pathology. The Wilcoxon Signed-Rank test was performed to obtain the p value in the
were performed using IBM SPSS 24 for Mac.
MA
3. Results
NU
comparison of the BNIPS and VAS at the different times they were evaluated. All calculations
D
3.1. Population
PT E
Twenty-six patients fulfilled the criteria in the IHS classification for Occipital Neuralgia, and entered the algorithm, of these subjects, 22 were women (85%) and the mean age was of 53.9
CE
years with an SD of 11.8 years. (Table 3)
AC
The most common laterality of the pain was right in 18 cases (69%) and the involved nerves were the GON in 100% of cases and in 24% of cases there were two nerves involved, the LON in 20% and the third occipital nerve in 4%. Ten subjects (38%) had the previous history of a whiplash injury in the neck in the past two years before their intervention.
ACCEPTED MANUSCRIPT 3.2. Local Injection All 26 patients underwent local injection using the previously described method, of which at 4 weeks follow up 22 presented an improvement in subjective pain of more than 50% and according to the algorithm were offered the decompression and neurectomy, the other 4 subjects presented an improvement of less than 50% and were sent for reevaluation and
RI
3.3. Surgical Decompression and Neurectomy
PT
started medical treatment. No complications were reported for this intervention.
SC
Twenty-two cases underwent microsurgical decompression, of which 4 were excluded for
NU
analysis in this study due to the fact they do not have adequate follow-up notes, with no information of the Barrow Neurological Institute Pain Scale (BNIPS) and Visual Analogue
MA
Scale (VAS). (Table 4)
In the 18 analyzed cases the surgical time had a mean of 70 minutes with a standard deviation
D
(SD) of 21.62 minutes, the estimated blood loss was 56.1 milliliters with an SD of 54.7
PT E
milliliters.
The most common laterality of the pain was right in 12 cases (66%) and only in 5 cases (27%)
CE
two nerves were involved in the pain etiology in one case it was the third occipital nerve
AC
which was approached using the same incision as the one used for the GON and in the other four cases it was the LON which was approached using the incision described in (Figure 4), the results of the general characteristics of subjects who underwent the operation are summarized in Table 4 In the immediate postoperative evaluation which was performed during the hospitalization period which was the same for all subjects (24 hours), we observed a clear diminish in both pain scales, in the BNIPS the reduction in pain was of 50% and in the VAS 62%. Using the Wilcoxon Signed-Rank Test we obtained the Z value for both scales in the preoperative and
ACCEPTED MANUSCRIPT postoperative evaluation resulting statistically significant for p<0.01 in both scales, this is summarized in Table 5, all patients presented anesthesia in the C2 dermatome on the side of the surgery in this evaluation. No complications from the surgery were reported and all patients were discharged in less than 24 hours posterior to the operation.
PT
3.4. Follow Up
RI
At 3 & 6 months follow up the benefits in term of pain control (BNIPS) and pain intensity
SC
(VAS) were still present, of the decompression and neurectomy, no increase in either
NU
frequency or intensity of pain was noted, there was a small reduction in the BNIPS scale and VAS as well but were not significantly different than in the postoperative evaluation. Out of
MA
the 18 cases, 10 have follow-ups up to 12 months and 7 to 18 months showing that the benefit in both scales is still present with no significant increase.
D
In terms of the sensitivity in the C2 dermatome, 10 subjects regained normal sensitivity at 3
PT E
months and 12 subjects at 6 months, only 6 subjects persisted with anesthesia at the end of
3.5. Pathology
CE
this period.
AC
Pathology results for the 18 subjects were reported as perineural fibrosis and vascular congestion around the nerves.
4. Discussion Even though prevalence and incidence in this pathology is not well known and there is only one report in the literature stating that the incidence is around 3.2/100,000/year2 we found that in our population this incidence is much smaller, at 1.2/100,000/year which may result
ACCEPTED MANUSCRIPT from the characteristics of our own population which is comprised only by the Mexican Oil Company workers and their family being most of our affiliates of young age, also most of our affiliates are male and as it is demonstrated in this case series this disease is more prevalent in females. One of the main reasons to propose this type of surgery is that the other main options for
PT
treatment such as radiofrequency are not widely available in our country and the pain
RI
management using medications is not as effective due to the poor adherence to the drugs used to treat occipital neuralgia and the side effects that they produce, it has been noticed in other
SC
pathologies such as cancer than adherence to analgesic regimes is very poor and that this
NU
significantly damages the ability of an adequate pain control.11
The neurectomy technique we modified poses a small risk for complications and mortality, in
MA
our case series this was 0%, and the cost-effectivenes of this potentially curative treatment is much greater than having subjects with occipital neuralgia receiving medications or
PT E
D
continuous therapies of occipital nerve stimulation, it is widely known that the surgical options have substantial benefits in carefully selected pain patients12 which is the main reason why we have a complex algorithm involving trial of the potential benefit before
CE
performing the surgery.
AC
As it is known the main etiology for occipital neuralgia is the formation of fibrosis and muscle contraction in the area in which the nerve exits the fascia, in our case series 38% of the subjects had the past medical history of neck trauma which could have been the cause of fibrosis and muscle contraction in this area. In the remainder of subjects in which fibrosis was always found without a history of neck trauma, other physical stressors in life might have been submitted small repetitive neck trauma .
ACCEPTED MANUSCRIPT 5. Conclusion Microsurgical decompression of the occipital nerves along with neurectomy is a safe and effective alternative to treat occipital neuralgia with satisfactory results. We recommend the use of the infiltration diagnostic and therapeutic test to confirm the
PT
diagnosis of occipital neuralgia before proposing any type of surgical intervention for this
RI
pathology.
The sensitivity disturbances after neurectomy of the GON, LON or III ON are usually reversible
SC
within 6 months of neurectomy.
NU
The Barrow Neurological Institute Pain Score is the best tool to categorize this type of patients
MA
due to the fact that it is designed for neuropathic pain.
6. Bibliography
Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia. 2013;33(9):629-808. doi:10.1177/0333102413485658.
2.
Koopman JSHA, Dieleman JP, Huygen FJ, de Mos M, Martin CGM, Sturkenboom MCJM. Incidence of facial pain in the general population. Pain. 2009;147(1-3):122-127. doi:10.1016/j.pain.2009.08.023.
3.
Choi I, Jeon SR. Neuralgias of the Head: Occipital Neuralgia. J Korean Med Sci. 2016;31(4):479-488. doi:10.3346/jkms.2016.31.4.479.
4.
Sweet JA, Mitchell LS, Narouze S, et al. Occipital Nerve Stimulation for the Treatment of Patients With Medically Refractory Occipital Neuralgia: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline. Neurosurgery. 2015;77(3):332-341. doi:10.1227/NEU.0000000000000872.
5.
Ducic I, Hartmann EC, Larson EE. Indications and Outcomes for Surgical Treatment of Patients with Chronic Migraine Headaches Caused by Occipital Neuralgia. Plastic and Reconstructive Surgery. 2009;123(5):1453-1461. doi:10.1097/PRS.0b013e3181a0720e.
6.
Magnusson T, Ragnarsson T, Bjornsson AO. Occipital Nerve Release in Patients With Whiplash Trauma and Occipital Neuralgia. Headache. 1996;36(1):32-36. doi:10.1046/j.1526-4610.1996.3601032.x.
7.
Magnússon T, Ragnarsson T. Occipital Nerve Release in Patients With Whiplash Trauma
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CE
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D
1.
ACCEPTED MANUSCRIPT and Occipital Neuralgia - Magnússon - 2002 - Headache: The Journal of Head and Face Pain - Wiley Online Library. … The Journal of Head and Face …. 1996. Bovim G, Fredriksen TA, Stolt-Nielsen A, Sjaastad O. Neurolysis of the greater occipital nerve in cervicogenic headache. A follow up study. Headache. 1992;32(4):175-179.
9.
Poletti CE. Proposed operation for occipital neuralgia: C-2 and C-3 root decompression. Case report. Neurosurgery. 1983;12(2):221-224.
10.
Vital JM, Grenier F, Dautheribes M, Baspeyre H, Lavignolle B, Sénégas J. An anatomic and dynamic study of the greater occipital nerve (n. of Arnold). Applications to the treatment of Arnold's neuralgia. Surg Radiol Anat. 1989;11(3):205-210.
11.
Miaskowski C, Dodd MJ, West C, et al. Lack of Adherence With the Analgesic Regimen: A Significant Barrier to Effective Cancer Pain Management. Journal of Clinical Oncology. 2016;19(23):4275-4279. doi:10.1200/JCO.2001.19.23.4275.
12.
Turk DC. Clinical Effectiveness and Cost-Effectiveness of Treatments for Patients With Chronic Pain. The Clinical Journal of Pain. 2002;18(6):355.
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ACCEPTED MANUSCRIPT
Diagnostic Criteria for Occipital Neuralgia
Unilateral or Bilateral Pain fulfilling the next criteria:
PT
- Pain is located in the distribution of the greater, lesser and/or third occipital nerves.
RI
- Pain has two of the following three characteristics:
SC
1.- Recurring in paroxysmal attacks lasting from a few seconds to minutes.
NU
2.- Severe intensity.
D
- Pain is associated with both of the following:
MA
3.- Shooting, Stabbing or Sharp in quality.
PT E
1.- Dysaesthesia and/or allodynia apparent during innocuous stimulation of the scalp and/or hair.
CE
2.- Either or both of the following:
AC
a) Tenderness over the affected nerve branches.
b) Trigger points at the emergence of the Greater Occipital Nerve or in the area of distribution of C2
- Not better accounted for by another diagnosis.
Data obtained from the criteria of the International Headache Society
Table 1 Diagnostic Criteria of Occipital Neuralgia According to the IHS
ACCEPTED MANUSCRIPT
Pain Description
I
No Pain, no medications
II
Occasional pain, no medications required
III
Some pain, adequately controlled with medications
IV
Some pain, not adequately controlled with medications
V
Severe pain or no pain relief
MA
NU
SC
RI
PT
Score
AC
CE
PT E
D
Table 2 Barrow Neurological Institute Pain Score
ACCEPTED MANUSCRIPT Patient Characteristics
N = 26
Gender
4 (15%)
- Female
22 (85%)
Age
53.9 Years (SD 11.8)
RI
SC NU
Laterality of pain
- Right
18 (69%)
MA
- Left
8 (31%)
PT E
D
Involved Nerves (Number)
- One
AC
- GON only
20 (76%)
6 (24%)
CE
- Two
Involved Nerves
PT
- Male
20 (76%)
- GON + LON
5 (20%)
- GON + III ON
1 (4%)
ACCEPTED MANUSCRIPT Table 4: General Characteristics of the subjects who underwent decompression and Neurectomy
Patient Characteristics
N= 18
4 (22%)
- Female
14 (78%)
Age
52.9 Years (12.9 Years)
RI
- Male
PT
Gender
- Left
6 cases (34%)
13 (73%)
- Two
D
- One
PT E
Involved Nerves (Number)
NU
12 cases (66%)
MA
- Right
SC
Laterality of Pain
5 (27%)
- GON + LON
- GON + III ON
AC
- GON Only
CE
Involved Nerves
13 (73%)
4 (21%)
1 (6%)
Surgical Time
70 Minutes(21.62 Minutes)
Estimated Blood Loss
56.1 Milliliters (54.7 Milliliters)
Complications
0%
Age, surgical time and EBL are given in Mean and Standard Deviation
ACCEPTED MANUSCRIPT
Preoperative
Postoperative Score
Difference Wilcoxon Signed-Rank Test (p<0.01)
BNIPS
BNIPS
- M=3.5
- M = 1.77
- SD =0.61
- SD = 0.80
VAS
VAS
- M = 7.16
- M = 2.22
- SD = 2.25
- SD = 1.86
M = Mean
SD = Standard
P = 0.00038*
RI
50% ⇓
PT
Score
NU
SC
Z = -3.5494
P = 0.0002*
Z = -3.7236
PT E
D
MA
62% ⇓
CE
Deviation
AC
Table 5 Differences in Pain Scores after intervention
ACCEPTED MANUSCRIPT Abbreviations:
AC
CE
PT E
D
MA
NU
SC
RI
PT
GON = Greater Occipital Nerve LON = Lesser Occipital Nerve III ON = Third Occipital Nerve BNIPS = Barrow Neurological Institute Pain Score VAS = Visual Analogue Scale
ACCEPTED MANUSCRIPT
PT RI SC NU MA D PT E CE
Occipital Neuralgia is a disabling pain related disease. We provide the results of our treatment algorithm for occipital neuralgia, using a modified neurectomy technique. Pain control after occipital nerve neurectomy is excellent and safe to perform.
AC
Ulises García, Juan Del Castillo-Calcáneo, María Elena CordobaMosqueda PII: DOI: Reference:
S2214-7519(17)30157-3 doi: 10.1016/j.inat.2017.07.011 INAT 231
To appear in:
Interdisciplinary Neurosurgery: Advanced Techniques and Case Management
Received date: Revised date: Accepted date:
4 July 2017 11 July 2017 16 July 2017
Please cite this article as: Ulises García, Juan Del Castillo-Calcáneo, María Elena Cordoba-Mosqueda , Reappraisal of microsurgical decompression and neurectomy of the occipital nerve in the treatment of occipital neuralgia, Interdisciplinary Neurosurgery: Advanced Techniques and Case Management (2017), doi: 10.1016/j.inat.2017.07.011
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Reappraisal of Microsurgical Decompression and Neurectomy of the Occipital Nerve in the treatment of Occipital Neuralgia
Ɨ
1. 2.
Ɨ
Neurosurgery Department, Mexican Oil Company (Pemex) High Specialty Hospital, Mexico City, Mexico Neurosurgery, National Autonomous University of Mexico, Mexico City, Mexico
Ɨ
PT
Type of article:
SC
RI
Disclosures
AC
CE
PT E
D
MA
NU
Corresponding author:
1. Introduction
Occipital neuralgia is defined by the international headache society (IHS) as a unilateral or bilateral paroxysmal, shooting or stabbing pain in the posterior part of the scalp, in the distribution of the greater and lesser occipital nerves, sometimes accompanied by diminished sensation or dysaesthesia in the affected area and commonly associated with tenderness over
ACCEPTED MANUSCRIPT the involved nerve(s).1 This pain usually originates in the suboccipital region and irradiates to the vertex. There is no definitive data about the prevalence or incidence of occipital neuralgia, there is a dutch study which reported a low incidence of 3.2 per 100,000.2 however this is the only study that exists to date and is thought to be an underdiagnosed entity due to the number of
PT
differential diagnosis that are possible.
RI
Many etiologies of occipital neuralgia have been reported in the literature, however the most
SC
common one is of compressive origin either by trauma which causes subsequent fibrosis or by
NU
muscle contraction.3
There are currently various accepted treatment methods reported in the literature, ranging
MA
from medical treatment using neuropathic agents such as antiepileptic and/or antidepressant medications which is considered as the first line of treatment, local injections to the nerve
D
using local anesthetics combined with steroids are also considered a treatment as well as a
PT E
diagnostic test, lately nerve stimulation has been given much attention and even a systematic review and evidence-based guideline was published about this method concluding that it has
AC
CE
a level III recommendation strength. 4
Neurolysis of the occipital nerve (with or without sectioning of the inferior oblique muscle), C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, and
ACCEPTED MANUSCRIPT neurectomy were historically introduced for medically re-fractory patients.
5-9
But ultimately
have lost its place in favor of nerve stimulation. Our aim in this study is to report our experience and treatment algorithm with our modified neurectomy surgical technique which provides excellent results in pain control for patients who suffer occipital neuralgia and that can be considered as a safe alternative when
RI
2. Methods
PT
neurostimulation and radiofrequency are not available.
SC
We performed a retrospective chart review of all 26 subjects diagnosed with Occipital
NU
Neuralgia from January 2014 when our treatment algorithm started to be used in our institution and obtained an 18 subjects case series with follow ups of 6 months who
MA
underwent our treatment algorithm for Occipital Neuralgia.
D
2.1. Patient selection
PT E
Starting in January 2014 all patients that were diagnosed with occipital neuralgia under the IHS classification comprising the next clinical features (Table 1) were enrolled to our
CE
algorithm for occipital neuralgia treatment. (Figure 1)
AC
2.2. Treatment Algorithm After being diagnosed clinically as occipital neuralgia, all patients underwent the treatment algorithm, in which as a mean of confirmation of the neuralgia and as a treatment method they were offered a local injection with ropivacaine and dexamethasone, patients were required to sign an informed consent in order to obtain the injection, if they refused they were treated medically only with option to receive the injection if they ultimately decided to sign the consent.
ACCEPTED MANUSCRIPT 26 patients were identified with occipital neuralgia, all patients signed the consent and underwent the local injection first and 22 underwent microsurgical decompression and neurectomy, however we reduced our case series to 18 due to incomplete follow-up in 4 cases. All cases received evaluation using the Barrow Neurological Institute Pain Score (BNIPS)
PT
(Table 2) in order to evaluate the pain frequency and control as well as the Visual Analogue
RI
Scale (VAS) to evaluate pain intensity and clinical evaluation of sensitivity in the C2
SC
dermatome.
NU
2.3. Local Injection
Once the side and affected nerves were identified, we injected either 1 or 2 points (this
MA
depended on the number of nerves affected, if it was only the GON, LON or both) in accordance to the Vital and Becser10 previously reported technique, we used for injection a
PT E
we injected 10ml. (Figure 2)
D
combination of ropivacaine 7.5% and dexamethasone 8mg titered at 1:1 ratio, for each point
After local injection patients were immediately discharged and came back for evaluation at 6
CE
weeks, if the improvement on VAS and BNIPS was more than 50% then the patient was deemed as a good candidate for surgical decompression and neurectomy of the affected nerve
AC
and the surgery was offered, out of the 26 subjects, 22 accepted the surgical treatment immediately, the other 4 presented reduction in pain less than 50% and entered the algorithm for reevaluation and medical treatment and are currently being followed.
2.4. Surgical procedure 2.4.1. Patient Positioning The subjects were placed in a prone position with the head resting on a horseshoe adapter for the mayfield headrest with a 45 degree flexion of the neck to provide better exposure of the
ACCEPTED MANUSCRIPT cervical spinous processes and the inion to locate the superficial landmarks, the thorax is placed over two gel rolls and all of the pressure points are padded. (Figure 3) 2.4.2. Incision Planning and superficial landmarks Incision was planned according to the affected side and nerves, if the neurolysis was going to be of the GON a linear 3cm incision was made cm from the midline at the level of the inion,
PT
extending 1.5cm superior and 1.5cm inferior. If the LON was the affected nerve then the
RI
incision would be made cm from the midline, if both nerves were affected then the incision
SC
would be made at the midpoint of this two markings. (Figure 4) 2.4.3. Microsurgical Decompression and Neurectomy.
NU
The incision was performed using an 11 blade and careful blunt dissection through the
MA
subcutaneous plane is made with metzenbaum scissors approximately 1cm to each side until the nerve is identified, for faster identification of the nerve we suggest using the occipital
D
artery pulsations since in this portion of the nerve the artery is adjacent to it, then the nerve
PT E
trajectory is followed while performing its decompression from the P2 portion at the exit point in the nuchal line to 3cm distal to the exit point, the proximal end of the nerve is ligated
CE
using 2-0 chromic catgut to avoid formation of neuromas and the nerve is excised completely along with the fibrosis surrounding it and sent to pathology.
AC
2.4.4. Closure.
After decompression and neurectomy had been achieved, hemostasis was ensured with bipolar coagulation and a two-stage closure performed, closing the galea and subcutaneous tissue with interrupted inverted 2-0 vicryl, the superficial skin was closed using a subcutaneous continuous suture with 3-0 monocryl.
ACCEPTED MANUSCRIPT 2.5. Post-Surgery Follow Up All patients remained hospitalized for 24 hours after surgical decompression for pain evaluation. Subjects were evaluated using the VAS and BNIPS at the immediate postoperative time (24 hours) as well as 3 and 6 months postoperatively. Sensitivity in the C2 area was also evaluated.
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2.6. Statistical Analysis
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Median and standard deviations were used to describe the population of the study as well as
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the pathology. The Wilcoxon Signed-Rank test was performed to obtain the p value in the
were performed using IBM SPSS 24 for Mac.
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3. Results
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comparison of the BNIPS and VAS at the different times they were evaluated. All calculations
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3.1. Population
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Twenty-six patients fulfilled the criteria in the IHS classification for Occipital Neuralgia, and entered the algorithm, of these subjects, 22 were women (85%) and the mean age was of 53.9
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years with an SD of 11.8 years. (Table 3)
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The most common laterality of the pain was right in 18 cases (69%) and the involved nerves were the GON in 100% of cases and in 24% of cases there were two nerves involved, the LON in 20% and the third occipital nerve in 4%. Ten subjects (38%) had the previous history of a whiplash injury in the neck in the past two years before their intervention.
ACCEPTED MANUSCRIPT 3.2. Local Injection All 26 patients underwent local injection using the previously described method, of which at 4 weeks follow up 22 presented an improvement in subjective pain of more than 50% and according to the algorithm were offered the decompression and neurectomy, the other 4 subjects presented an improvement of less than 50% and were sent for reevaluation and
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3.3. Surgical Decompression and Neurectomy
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started medical treatment. No complications were reported for this intervention.
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analysis in this study due to the fact they do not have adequate follow-up notes, with no information of the Barrow Neurological Institute Pain Scale (BNIPS) and Visual Analogue
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Scale (VAS). (Table 4)
In the 18 analyzed cases the surgical time had a mean of 70 minutes with a standard deviation
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(SD) of 21.62 minutes, the estimated blood loss was 56.1 milliliters with an SD of 54.7
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milliliters.
The most common laterality of the pain was right in 12 cases (66%) and only in 5 cases (27%)
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two nerves were involved in the pain etiology in one case it was the third occipital nerve
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which was approached using the same incision as the one used for the GON and in the other four cases it was the LON which was approached using the incision described in (Figure 4), the results of the general characteristics of subjects who underwent the operation are summarized in Table 4 In the immediate postoperative evaluation which was performed during the hospitalization period which was the same for all subjects (24 hours), we observed a clear diminish in both pain scales, in the BNIPS the reduction in pain was of 50% and in the VAS 62%. Using the Wilcoxon Signed-Rank Test we obtained the Z value for both scales in the preoperative and
ACCEPTED MANUSCRIPT postoperative evaluation resulting statistically significant for p<0.01 in both scales, this is summarized in Table 5, all patients presented anesthesia in the C2 dermatome on the side of the surgery in this evaluation. No complications from the surgery were reported and all patients were discharged in less than 24 hours posterior to the operation.
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At 3 & 6 months follow up the benefits in term of pain control (BNIPS) and pain intensity
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(VAS) were still present, of the decompression and neurectomy, no increase in either
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frequency or intensity of pain was noted, there was a small reduction in the BNIPS scale and VAS as well but were not significantly different than in the postoperative evaluation. Out of
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the 18 cases, 10 have follow-ups up to 12 months and 7 to 18 months showing that the benefit in both scales is still present with no significant increase.
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In terms of the sensitivity in the C2 dermatome, 10 subjects regained normal sensitivity at 3
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months and 12 subjects at 6 months, only 6 subjects persisted with anesthesia at the end of
3.5. Pathology
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this period.
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Pathology results for the 18 subjects were reported as perineural fibrosis and vascular congestion around the nerves.
4. Discussion Even though prevalence and incidence in this pathology is not well known and there is only one report in the literature stating that the incidence is around 3.2/100,000/year2 we found that in our population this incidence is much smaller, at 1.2/100,000/year which may result
ACCEPTED MANUSCRIPT from the characteristics of our own population which is comprised only by the Mexican Oil Company workers and their family being most of our affiliates of young age, also most of our affiliates are male and as it is demonstrated in this case series this disease is more prevalent in females. One of the main reasons to propose this type of surgery is that the other main options for
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treatment such as radiofrequency are not widely available in our country and the pain
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management using medications is not as effective due to the poor adherence to the drugs used to treat occipital neuralgia and the side effects that they produce, it has been noticed in other
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pathologies such as cancer than adherence to analgesic regimes is very poor and that this
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significantly damages the ability of an adequate pain control.11
The neurectomy technique we modified poses a small risk for complications and mortality, in
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our case series this was 0%, and the cost-effectivenes of this potentially curative treatment is much greater than having subjects with occipital neuralgia receiving medications or
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continuous therapies of occipital nerve stimulation, it is widely known that the surgical options have substantial benefits in carefully selected pain patients12 which is the main reason why we have a complex algorithm involving trial of the potential benefit before
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performing the surgery.
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As it is known the main etiology for occipital neuralgia is the formation of fibrosis and muscle contraction in the area in which the nerve exits the fascia, in our case series 38% of the subjects had the past medical history of neck trauma which could have been the cause of fibrosis and muscle contraction in this area. In the remainder of subjects in which fibrosis was always found without a history of neck trauma, other physical stressors in life might have been submitted small repetitive neck trauma .
ACCEPTED MANUSCRIPT 5. Conclusion Microsurgical decompression of the occipital nerves along with neurectomy is a safe and effective alternative to treat occipital neuralgia with satisfactory results. We recommend the use of the infiltration diagnostic and therapeutic test to confirm the
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diagnosis of occipital neuralgia before proposing any type of surgical intervention for this
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pathology.
The sensitivity disturbances after neurectomy of the GON, LON or III ON are usually reversible
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within 6 months of neurectomy.
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The Barrow Neurological Institute Pain Score is the best tool to categorize this type of patients
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due to the fact that it is designed for neuropathic pain.
6. Bibliography
Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia. 2013;33(9):629-808. doi:10.1177/0333102413485658.
2.
Koopman JSHA, Dieleman JP, Huygen FJ, de Mos M, Martin CGM, Sturkenboom MCJM. Incidence of facial pain in the general population. Pain. 2009;147(1-3):122-127. doi:10.1016/j.pain.2009.08.023.
3.
Choi I, Jeon SR. Neuralgias of the Head: Occipital Neuralgia. J Korean Med Sci. 2016;31(4):479-488. doi:10.3346/jkms.2016.31.4.479.
4.
Sweet JA, Mitchell LS, Narouze S, et al. Occipital Nerve Stimulation for the Treatment of Patients With Medically Refractory Occipital Neuralgia: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline. Neurosurgery. 2015;77(3):332-341. doi:10.1227/NEU.0000000000000872.
5.
Ducic I, Hartmann EC, Larson EE. Indications and Outcomes for Surgical Treatment of Patients with Chronic Migraine Headaches Caused by Occipital Neuralgia. Plastic and Reconstructive Surgery. 2009;123(5):1453-1461. doi:10.1097/PRS.0b013e3181a0720e.
6.
Magnusson T, Ragnarsson T, Bjornsson AO. Occipital Nerve Release in Patients With Whiplash Trauma and Occipital Neuralgia. Headache. 1996;36(1):32-36. doi:10.1046/j.1526-4610.1996.3601032.x.
7.
Magnússon T, Ragnarsson T. Occipital Nerve Release in Patients With Whiplash Trauma
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1.
ACCEPTED MANUSCRIPT and Occipital Neuralgia - Magnússon - 2002 - Headache: The Journal of Head and Face Pain - Wiley Online Library. … The Journal of Head and Face …. 1996. Bovim G, Fredriksen TA, Stolt-Nielsen A, Sjaastad O. Neurolysis of the greater occipital nerve in cervicogenic headache. A follow up study. Headache. 1992;32(4):175-179.
9.
Poletti CE. Proposed operation for occipital neuralgia: C-2 and C-3 root decompression. Case report. Neurosurgery. 1983;12(2):221-224.
10.
Vital JM, Grenier F, Dautheribes M, Baspeyre H, Lavignolle B, Sénégas J. An anatomic and dynamic study of the greater occipital nerve (n. of Arnold). Applications to the treatment of Arnold's neuralgia. Surg Radiol Anat. 1989;11(3):205-210.
11.
Miaskowski C, Dodd MJ, West C, et al. Lack of Adherence With the Analgesic Regimen: A Significant Barrier to Effective Cancer Pain Management. Journal of Clinical Oncology. 2016;19(23):4275-4279. doi:10.1200/JCO.2001.19.23.4275.
12.
Turk DC. Clinical Effectiveness and Cost-Effectiveness of Treatments for Patients With Chronic Pain. The Clinical Journal of Pain. 2002;18(6):355.
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Diagnostic Criteria for Occipital Neuralgia
Unilateral or Bilateral Pain fulfilling the next criteria:
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- Pain is located in the distribution of the greater, lesser and/or third occipital nerves.
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- Pain has two of the following three characteristics:
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1.- Recurring in paroxysmal attacks lasting from a few seconds to minutes.
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2.- Severe intensity.
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- Pain is associated with both of the following:
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3.- Shooting, Stabbing or Sharp in quality.
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1.- Dysaesthesia and/or allodynia apparent during innocuous stimulation of the scalp and/or hair.
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2.- Either or both of the following:
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a) Tenderness over the affected nerve branches.
b) Trigger points at the emergence of the Greater Occipital Nerve or in the area of distribution of C2
- Not better accounted for by another diagnosis.
Data obtained from the criteria of the International Headache Society
Table 1 Diagnostic Criteria of Occipital Neuralgia According to the IHS
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Pain Description
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No Pain, no medications
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Occasional pain, no medications required
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Some pain, adequately controlled with medications
IV
Some pain, not adequately controlled with medications
V
Severe pain or no pain relief
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Score
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Table 2 Barrow Neurological Institute Pain Score
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N = 26
Gender
4 (15%)
- Female
22 (85%)
Age
53.9 Years (SD 11.8)
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Laterality of pain
- Right
18 (69%)
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- Left
8 (31%)
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Involved Nerves (Number)
- One
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- GON only
20 (76%)
6 (24%)
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- Two
Involved Nerves
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- Male
20 (76%)
- GON + LON
5 (20%)
- GON + III ON
1 (4%)
ACCEPTED MANUSCRIPT Table 4: General Characteristics of the subjects who underwent decompression and Neurectomy
Patient Characteristics
N= 18
4 (22%)
- Female
14 (78%)
Age
52.9 Years (12.9 Years)
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- Male
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Gender
- Left
6 cases (34%)
13 (73%)
- Two
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- One
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Involved Nerves (Number)
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12 cases (66%)
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- Right
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Laterality of Pain
5 (27%)
- GON + LON
- GON + III ON
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- GON Only
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Involved Nerves
13 (73%)
4 (21%)
1 (6%)
Surgical Time
70 Minutes(21.62 Minutes)
Estimated Blood Loss
56.1 Milliliters (54.7 Milliliters)
Complications
0%
Age, surgical time and EBL are given in Mean and Standard Deviation
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Preoperative
Postoperative Score
Difference Wilcoxon Signed-Rank Test (p<0.01)
BNIPS
BNIPS
- M=3.5
- M = 1.77
- SD =0.61
- SD = 0.80
VAS
VAS
- M = 7.16
- M = 2.22
- SD = 2.25
- SD = 1.86
M = Mean
SD = Standard
P = 0.00038*
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50% ⇓
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Score
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Z = -3.5494
P = 0.0002*
Z = -3.7236
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62% ⇓
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Deviation
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Table 5 Differences in Pain Scores after intervention
ACCEPTED MANUSCRIPT Abbreviations:
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GON = Greater Occipital Nerve LON = Lesser Occipital Nerve III ON = Third Occipital Nerve BNIPS = Barrow Neurological Institute Pain Score VAS = Visual Analogue Scale
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Occipital Neuralgia is a disabling pain related disease. We provide the results of our treatment algorithm for occipital neuralgia, using a modified neurectomy technique. Pain control after occipital nerve neurectomy is excellent and safe to perform.
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