The authors acknowledge the technical assistance of Alexandra Curchod, Yuliethe Martins, and the Filmatik Global team. This work was funded in its entirety by the Global Medical Institute.

The data collection was conducted as a retrospective quality assessment study and the analysis of the results was approved by the internal review board at University of Padua. All procedures were performed in accordance with the ethical standards of the national research committee and the 1964 Helsinki Declaration and its later amendments. All patients have signed an informed consent allowing the authors to anonymously use the retrospective data. For this study, 87 patients were included.
1. Selection of candidates
<ol>
	<li>Select patients based on a constellation of symptoms compatible with occipital neuralgia, including at least three of the following characteristics: aching, burning, and throbbing pain, starting in the pit between the insertion of the trapezius muscle and the sternocleidomastoid muscle (here defined as the occipital triangle); the pain travels in the scalp along the trajectory of the occipital nerves from the back of the head to the temples and front on one or both sides of the head; the pain can resemble an electrical shock; the pain can be elicited/worsened by particular positions of the head (hyperextension of the neck, rotation of the head, etc.) also while sleeping; the pain often is felt behind the eyes; the scalp can exhibit allodynia; patients may have migraines and cluster headaches in addition to occipital neuralgia.</li>
	<li>To be included, ensure patients respond with at least 50% decrease in pain after selective blocks of the occipital nerves.</li>
	<li>Use the following exclusion criteria: pain started after trauma like whiplash injury; pain started after surgery or radiotherapy with direct or indirect nerve injury; patients not responding to selective nerve blocks.</li>
</ol>
2. Nerve block procedure
<ol>
	<li>Prepare the infiltration mixture as 1.5 mL of 1% lidocaine with epinephrine (1% Rapidocain 10 mg/mL) and 1 cc of 40 mg Triamcinolone (40 mg/mL) in a 5 cc syringe prepared with a 30G needle.</li>
	<li>Transfer the mixture into a 5 mL syringe (Luer Lock) with a 30G needle (0.3 mm x 13 mm).</li>
	<li>Identify the site of injection by palpation. Identify the lateral edge of the proximal trapezius insertion and medial edge of the proximal sternocleidomastoid (SCM) muscle insertion, just below the nuchal line. The pit between these structures corresponds to the target injection point.</li>
	<li>Palpate the occipital artery passage above the nuchal line. Confirm the occipital neurovascular bundle (greater and lesser occipital nerve and occipital artery) position below the nuchal line using Doppler (10 MHz). Move the doppler probe caudally toward the occipital triangle and confirm the passage of the artery in this place by an arterial signal.</li>
	<li>Perform gentle aspiration with the syringe before injection (if blood is aspirated the needle is retracted a few mm) to prevent intravascular injection. If the patient feels electric shocks along the occipital nerve path, withdraw the needle a few mm to avoid intraneural injection and nerve damage.</li>
	<li>To ensure that the nerve block has been performed correctly, palpate the back scalp to allow the patient to confirm decreased sensation.</li>
</ol>
3. Preparation of the instrumentation table
<ol>
	<li>Drape the instrumentation table with laminar flow with sterile clothing. Prepare the following instruments: Surgical knife with blade No. 15, surgical Hudson forceps, needle holder, dissection scissors, bipolar forceps, lighted retractor, Nylon 5/0 suture, sterile gloves, Chlorhexidine disinfection, sterile paper tape.</li>
</ol>
4. Patient preparation
<ol>
	<li>Identify the most tender point with the patient sitting upright using palpation within the area where the nerve block was performed.</li>
	<li>Mark the incision site with a 2 to 3 cm oblique incision line across the tender area. Shave the area comprising the incision line and 1 cm around with a surgical shaver.</li>
</ol>
5. Surgeon preparation
<ol>
	<li>The surgeon wears 2.5x - 3.5x magnifying loops, surgical cap, and mask. Wash hands with soap and disinfect hands with antiseptic solution.</li>
</ol>
6. Surgical technique
<ol>
	<li>Patient positioning: Position the patients either laterally (in case of one-sided ON) or prone (for bilateral ON) on the surgical table.</li>
	<li>Local anesthesia: Administer local anesthesia, consisting of 5 mL of lidocaine with epinephrine, injected along the incision line via a 30G needle.</li>
	<li>Incision: Make an oblique, beveled incision, measuring 2.5 to 3.5 cm, centered in a region defined as the occipital triangle, bordered cranially by the nuchal line, medially by the lateral edge of the trapezius, and laterally by the medial edge of the sternocleidomastoid muscle using a No. 15 surgical blade.</li>
	<li>Nuchal line exposure: Incise the superficial layer of the nuchal line with the scalpel and dissect with dissection scissors to expose the greater occipital nerve (GON), occipital artery, and lymph nodes.</li>
	<li>Nerve exploration: Follow the GON meticulously along all points of possible compression using dissection scissors to create the space. Perform proximal release of the inferior fascia of the trapezius muscle with dissection scissors, semispinalis muscle fascia, and distal nuchal line fibers.</li>
	<li>Vascular and lymphatic structures: In instances where the occipital artery and lymph nodes come into contact with the nerves, reposition or excise these structures delicately with Hudson&#39;s surgical forceps. Gently disengage the adventitial and periarterial tissues with Hudson&#39;s surgical forceps, abundant in afferent and efferent autonomic nervous system fibers, in all cases (arteriolysis).</li>
	<li>Addressing neurovascular contact points: When a non-otherwise addressable conflict is found (such as a branch of the artery passing through the nerve fibers), divide this arterial segment (arteriotomy).</li>
	<li>Nerve blocks: Before closure, perform nerve blocks using 1% lidocaine with epinephrine sprayed directly on the nerve branches via a 30G needle. Ask the patient to move the head and talk to confirm complete decompression.</li>
	<li>Closure: Repair skin with single stitches of 5-0 nylon sutures. Dress the opening with moisture permeable spray dressing and sterile gauzes, held in place by paper tape.</li>
</ol>
7. Postoperative protocol
<ol>
	<li>Postoperative head movements: After the procedure, ask the patient to gently move the head in all directions at least 3x a day to prevent the formation of adhesions between the nerve fibers and the scar for a period of 2 to 3 weeks.</li>
	<li>Suture removal: Remove sutures 10 days after the procedure.</li>
	<li>Ask patients to continue their medications in case of headaches. Tell the patient to expect decreased sensation or anesthesia in the territory of the greater occipital nerve for a variable period between a few hours and a few days after the operation.</li>
	<li>Instruct patients to take ibuprofen 400-600 mg, 3x day for 3 days after the procedure.</li>
</ol>

Relieving Occipital Neuralgia: Nerve and Muscle-Preserving Decompression

<ol>
	<li>IHS. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+international+classification+of+headache+disorders,+3rd+edition.">The international classification of headache disorders, 3rd edition.</a> Cephalalgia. 38 (1), 1-211 (2018).</li><li>Mosser, S. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anatomy+of+the+greater+occipital+nerve:+implications+for+the+etiology+of+migraine+headaches.">The anatomy of the greater occipital nerve: implications for the etiology of migraine headaches.</a> Plast Reconstr Surg. 113 (2), 693-697 (2004).</li><li>Janis, J. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurovascular+compression+of+the+greater+occipital+nerve:+implications+for+migraine+headaches.">Neurovascular compression of the greater occipital nerve: implications for migraine headaches.</a> Plast Reconstr Surg. 126 (6), 1996-2001 (2010).</li><li>Guyuron, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Five-year+outcome+of+surgical+treatment+of+migraine+headaches.">Five-year outcome of surgical treatment of migraine headaches.</a> Plast Reconstr Surg. 127 (2), 603-608 (2011).</li><li>Blake, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+patients+with+chronic+occipital+headache+after+occipital+nerve+decompression+surgery:+A+case+series.">Tracking patients with chronic occipital headache after occipital nerve decompression surgery: A case series.</a> Cephalalgia. 39 (4), 556-563 (2019).</li><li>Pietramaggiori, G., Scherer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimally+invasive+nerve-+and+muscle-sparing+surgical+decompression+for+occipital+neuralgia.">Minimally invasive nerve- and muscle-sparing surgical decompression for occipital neuralgia.</a> Plast Reconstr Surg. 151 (1), 169-177 (2023).</li><li>Tobin, J., Flitman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+migraine+with+occipital+nerve+blocks+using+only+corticosteroids.">Treatment of migraine with occipital nerve blocks using only corticosteroids.</a> Headache. 51 (1), 155-159 (2011).</li><li>Seyed Forootan, N. S., Lee, M., Guyuron, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Migraine+headache+trigger+site+prevalence+analysis+of+2590+sites+in+1010+patients.">Migraine headache trigger site prevalence analysis of 2590 sites in 1010 patients.</a> J Plast Reconstr Aesthet Surg. 70 (2), 152-158 (2017).</li><li>Pietramaggiori, G., Scherer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Minimally invasive surgery for chronic pain management. , (2020).</li><li>Janis, J. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anatomy+of+the+greater+occipital+nerve:+Part+II.+Compression+point+topography.">The anatomy of the greater occipital nerve: Part II. Compression point topography.</a> Plast Reconstr Surg. 126 (5), 1563-1572 (2010).</li><li>Ducic, I., Moriarty, M., Al-Attar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+variations+of+the+occipital+nerves:+implications+for+the+treatment+of+chronic+headaches.">Anatomical variations of the occipital nerves: implications for the treatment of chronic headaches.</a> Plast Reconstr Surg. 123 (3), 859-863 (2009).</li><li>Junewicz, A., Katira, K., Guyuron, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+anatomical+variations+during+greater+occipital+nerve+decompression.">Intraoperative anatomical variations during greater occipital nerve decompression.</a> J Plast Reconstr Aesthet Surg. 66 (10), 1340-1345 (2013).</li><li>Scherer, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+greater+occipital+nerve+and+obliquus+capitis+inferior+muscle:+Anatomical+interactions+and+implications+for+occipital+pain+syndromes.">The greater occipital nerve and obliquus capitis inferior muscle: Anatomical interactions and implications for occipital pain syndromes.</a> Plast Reconstr Surg. 144 (3), 730-736 (2019).</li><li>Koopman, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incidence+of+facial+pain+in+the+general+population.">Incidence of facial pain in the general population.</a> Pain. 147 (1-3), 122-127 (2009).</li><li>Mathew, P. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+of+occipital+neuralgia+at+a+community+hospital-based+headache+clinic.">Prevalence of occipital neuralgia at a community hospital-based headache clinic.</a> Neurol Clin Pract. 11 (1), 6-12 (2021).</li></ol>

The authors declare no competing financial interests.

Occipital neuralgia is one of the most debilitating forms of headaches, mainly due to the chronic pain that is unremitting. A study on the prevalence of facial pain in 2009, which is often used as a reference for occipital neuralgia, found an ON prevalence of 3.2 per 100,00014. These statistics largely underestimate the problem, knowing that ON is responsible for facial pain in only 8.3% of the cases and that up to 25% of the cases of emergency room admittance are for headaches due to occipital neuralgia15.
We find in our practice that ON alone or in combination with other migraines is one of the most prevalent forms of chronic headaches, possibly due to morbid posture with the neck in flexion in front of computers and smartphones several hours per day, sedentary lifestyle, and limited time outdoors. 
The surgical approach outlined here offers a highly efficient means of accessing the occipital nerves under local anesthesia. Greater occipital neuralgia may coexist with lesser occipital neuralgia as these nerves have communicating branches and their territories overlap. By using the same surgical approach, both nerves can be explored and decompressed when indicated6. Patient acceptance of the procedure has been favorable, with an average duration of approximately 45 to 60 min required for completion per side.
The meticulous identification and preservation of nerve fibers constitute a hallmark of this approach. Thanks to the minimally invasive nature of the procedure that can be performed in local anesthesia, the operator assesses the efficacy of decompression at the end of the procedure by instructing the patient to engage in head movement and conversation, thereby ensuring the absence of residual compression points.
A crucial facet of this procedure lies in the emphasis on early and frequent head mobilization, conducted multiple times daily. This practice serves to deter the formation of adhesions between nerve fibers and the surgical scar, which may otherwise impede recovery.
It is essential to acknowledge that not all patients are suitable candidates for this technique. Notably, individuals with fragility or heightened anxiety levels may not tolerate the procedure comfortably under pure local anesthesia. In certain cases, patients may experience sudden discomfort, as even the slightest manipulation of an inflamed occipital nerve can trigger nerve firing. In these cases, local anesthesia is sprayed directly on the nerve fibers with immediate relief. 
This surgical approach represents a less invasive alternative compared to previously proposed decompression techniques. Its capacity to spare both nerve and muscle fibers contributes to a notable reduction in complication rates. We posit that this minimally invasive, yet highly effective methodology will broaden the accessibility of surgical decompression as a definitive treatment option for occipital neuralgia, offering hope to a wider spectrum of patients.

Occipital neuralgia (ON) is a chronic headache condition causing persistent dull pain in the back of the head1. The pain, which differs from typical migraines, is often resistant to standard migraine treatments due to mechanical compression on the occipital nerves2, particularly along their course through the nuchal line3. On the other hand, surgical options may be effective but involve invasive procedures and extended recovery times4,5. We present here a novel approach to the occipital nerves, allowing for minimally invasive decompression, minimal downtime, and preservation of muscle and sensitive nerve branches6.
Diagnosing ON relies on targeted nerve blocks, which temporarily reduce pain and help pinpoint the exact area of nerve compression7, guiding surgical decompression8,9. Unlike typical migraine management, our approach targets the root mechanical cause of ON, providing a viable therapeutic option beyond medication.
Numerous clinical and anatomical studies have led to the occipital nerve decompression technique as described in2,3,10,11,12,13. Although this technique has been proven safe and effective, the advantages of the minimally invasive technique presented here include reduced patient morbidity, abbreviated postoperative recovery periods, and lesser risks of iatrogenic-induced pain due to potential neuroma formation. In particular, the preservation of neural and muscular structures contributes to prompt and favorable outcomes. The greater and lesser occipital nerves can be exposed and decompressed via the described approach. For the purpose of this paper, only greater occipital nerve decompression is described to improve occipital neuralgia, which is due to lesser occipital neuralgia. The third occipital nerve is responsible for rare cases of occipital neuralgia in our practice, which are addressed with a separate approach due to its medial localization. The described technique includes the systematic exploration of the passage of the greater occipital nerve through the semispinalis capitis which may represent a compression point. Further research and clinical validation are warranted to ascertain the full scope of its efficacy and safety.

<table><tbody><tr><td>30G Needle</td><td>0.3x13 mm, BD Microlance 3, Spain</td><td></td><td></td></tr><tr><td>Bipolar Forceps</td><td>McPerson, bipolar forceps, Erbe, Switzerland</td><td>20195</td><td></td></tr><tr><td>Chlorhexidine</td><td>Hibidil, Chlorhexidini digluconas 0.5 mg/mL, Switzerland</td><td>120099</td><td></td></tr><tr><td>dissection scissors</td><td>Jarit supercut, Integra Lifescience, USA</td><td>323720</td><td></td></tr><tr><td>Doppler</td><td>Dopplex DMX Digital Doppler, High Sensitivity 10MHz probe, Huntleigh Healthcare, Wales, United Kingdom</td><td></td><td></td></tr><tr><td>Ethilon 5/0 Suture</td><td>Ethicon, USA</td><td>698 G</td><td></td></tr><tr><td>Lidocaine ephinephrine 1%</td><td>Rapidocain 1% 10 mg/mL, Sintetica, Switzerland</td><td></td><td></td></tr><tr><td>Lighted retractor</td><td>Electro Surgical Instrument Company, Rochester, NY</td><td>08-0195</td><td></td></tr><tr><td>Magnifying loops</td><td>Design for vision, USA</td><td></td><td></td></tr><tr><td>Opsity spray</td><td>Smith &amp;amp; Nephew, USA</td><td></td><td></td></tr><tr><td>Sterile gloves</td><td>Sempermed sintegra IR, Ireland</td><td></td><td></td></tr><tr><td>Sterillium</td><td>Sterillium disinfectant, Switzerland</td><td></td><td></td></tr><tr><td>Surgical blade n.15</td><td>Carbon steel surgical blades, Swann-Morton, England)</td><td>205</td><td></td></tr><tr><td>Surgical drapes and gauzes</td><td>Halyard Universal pack, USA</td><td>88761</td><td></td></tr><tr><td>Surgical instruments</td><td>Bontempi medical Italy</td><td></td><td></td></tr><tr><td>Surgical shaver</td><td>Carefusion, USA</td><td></td><td></td></tr><tr><td>Syringe 5cc</td><td>BBraun, Omnifix Luer Lock Solo, Switzerland</td><td></td><td></td></tr><tr><td>Triamcinolone 10mg</td><td>Triamcort depot 40 mg/mL, Zentiva Czech Republic</td><td></td><td></td></tr></tbody></table>

minimally invasive surgical decompression of occipital nerves

Occipital neuralgia (ON) stands out as one of the most distressing forms of headache disorders, distinguished by persistent pain at the base of the skull, recurring occipital headaches, and scalp dysesthesia or allodynia. ON is notorious for its unrelenting agony, severely impacting the lives of those afflicted. The incessant pain, often radiating upward from the base of the skull to the scalp, can be profoundly debilitating. Patients frequently endure excruciating occipital headaches, making even routine daily activities a formidable challenge. The added burden of scalp dysesthesia or allodynia, where seemingly innocuous stimuli elicit severe pain, compounds the suffering. This neuralgia primarily arises from the mechanical compression exerted on the occipital nerves along the nuchal line. In this paper, we present a minimally invasive nerve and muscle-preserving technique aimed at relieving this compression on the occipital nerves. Accurate diagnosis and effective treatment are paramount in providing relief for individuals battling this condition. Nerve blocks with local anesthesia have become a cornerstone of diagnosis, serving as both a confirmation of occipital neuralgia and a potential therapeutic intervention. These procedures offer crucial insights into the source of the pain while offering transient respite. However, the true breakthrough lies in the innovative technique we propose - a procedure that addresses the mechanical compression at the nuchal line, which is a prominent contributing factor to occipital neuralgia. By carefully decompressing the affected occipital nerves while preserving their integrity and surrounding muscle tissue, this minimally invasive approach offers patients a potential path to sustained relief. Remarkably, the procedure can be performed under local anesthesia, reducing the invasiveness of traditional surgeries and minimizing patient downtime.

At 1 year after the surgical decompression, there was a noteworthy reduction in chronic pain days, with a substantial decrease from an initial average of 25 days to 4.3 days (p &#60;0.01), reflecting an 80.5% reduction (a 5.8-fold decrease) in chronic pain frequency (Figure 1)6. Furthermore, the number of pain crisis days per month exhibited a remarkable decline, plummeting from 19 days to 3.7 days (p &#60;0.01), signifying an 82.8% reduction (a 5.1-fold decrease) in the frequency of pain crises (Figure 1 and Figure 2)6.
Patients reported an average background pain intensity of 3.7 on a scale of 10 before surgery, which substantially improved to 0.7 (p &#60;0.01) post-surgery, corresponding to an impressive 76.1% reduction (a 5.2-fold decrease) in background pain intensity6. Moreover, the peak pain intensity experienced during crises significantly diminished from 8.8/10 to 2.1/10 after surgery (p &#60;0.01), reflecting a substantial 81.1% reduction (a 4.2-fold decrease) in peak pain intensity (Figure 1 and Figure 2)6.
Remarkably, there was a significant reduction in the utilization of all types of drugs, including NSAIDs, triptans, and disease-modifying drugs, following the surgical intervention6 (not shown).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/66214/66214fig01.jpg" /> 
Figure 1: Clinical outcome after minimally invasive surgical decompression. After surgical decompression, chronic pain days decreased 5.8x. The pain crisis days/month decreased 5.1x. Background pain intensity decreased after surgery 5.2x, and pain intensity peaks during crises decreased 4.2x. (*p &#60;0.01, Two-tailed paired t tests, n=87). This figure has been modified from6. <a href="https://www.jove.com/files/ftp_upload/66214/66214fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/66214/66214fig02.jpg" /> 
Figure 2: Illustration of the anatomy of the occipital area pre- and post-decompression. In the pre-decompression picture, the external layer of the nuchal aponeurosis covers the occipital nerves and blood vessels. After decompression, the greater occipital nerve and occipital artery are visible. <a href="https://www.jove.com/files/ftp_upload/66214/66214fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Author Spotlight: Minimally Invasive Relief for Occipital Neuralgia at the Nuchal Line

The manuscript presents a minimally invasive nerve and muscle-sparing surgical protocol to decompress occipital nerves aiming to improve occipital neuralgia.

Minimally Invasive Surgical Decompression of Occipital Nerves

Occipital neuralgia (ON) stands out as one of the most distressing forms of headache disorders, distinguished by persistent pain at the base of the skull, ...

minimally-invasive-surgical-decompression-of-occipital-nerves

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JoVE Journal

Medicine

1.6K Views.  Global Medical Institute. The manuscript presents a minimally invasive nerve and muscle-sparing surgical protocol to decompress occipital nerves aiming to improve occipital neuralgia.

Video: Author Spotlight: Minimally Invasive Relief for Occipital Neuralgia at the Nuchal Line

Microvascular Decompression: Salient Surgical Principles and Technical Nuances

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports indicate that 80-90% of cases are related to compression of the trigeminal nerve by an adjacent vessel. The majority of patients with trigeminal neuralgia eventually require surgical management in order to achieve remission of symptoms. Surgical options for management include ablative procedures (e.g., radiosurgery, percutaneous radiofrequency lesioning, balloon compression, glycerol rhizolysis, etc.) and microvascular decompression. Ablative procedures fail to address the root cause of the disorder and are less effective at preventing recurrence of symptoms over the long term than microvascular decompression. However, microvascular decompression is inherently more invasive than ablative procedures and is associated with increased surgical risks. Previous studies have demonstrated a correlation between surgeon experience and patient outcome in microvascular decompression. In this series of 59 patients operated on by two neurosurgeons (JSN and PEK) since 2006, 93% of patients demonstrated substantial improvement in their trigeminal neuralgia following the procedure&#x2014;with follow-up ranging from 6 weeks to 2 years. Moreover, 41 of 66 patients (approximately 64%) have been entirely pain-free following the operation.
In this publication, video format is utilized to review the microsurgical pathology of this disorder. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed.

There are many available options for management of the patient with trigeminal neuralgia. Microvascular decompression, while the most invasive of all options, is also the most effective at achieving long term remission of symptoms. Video instruction on how to maximize efficacy and minimize complications with this procedure is described.

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports ...

Optic Nerve Transection: A Model of Adult Neuron Apoptosis in the Central Nervous System

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. 
The optic nerve can be accessed within the orbit of the eye and completely transected (axotomized), cutting the axons of the entire RGC population. Optic nerve 
transection is a reproducible model of apoptotic neuronal cell death in the adult CNS 1-4. This model is particularly attractive because the vitreous
 chamber of the eye acts as a capsule for drug delivery to the retina, permitting experimental manipulations via intraocular injections. The diffusion of chemicals 
through the vitreous fluid ensures that they act upon the entire RGC population. Moreover, RGCs can be selectively transfected by applying short interfering RNAs 
(siRNAs), plasmids, or viral vectors to the cut end of the optic nerve 5-7 or injecting vectors into their target, the superior colliculus 8. 
This allows researchers to study apoptotic mechanisms in the desired neuronal population without confounding effects on other bystander neurons or surrounding glia. 
An additional benefit is the ease and accuracy with which cell survival can be quantified after injury. The retina is a flat, layered tissue and RGCs are localized in 
the innermost layer, the ganglion cell layer. The survival of RGCs can be tracked over time by applying a fluorescent tracer (3% Fluorogold) to the cut end of the 
optic nerve at the time of axotomy, or by injecting the tracer into the superior colliculus (RGC target) one week prior to axotomy. The tracer is retrogradely transported, labeling 
the entire RGC population. Because the ganglion cell layer is a monolayer (one cell thick), RGC densities can be quantified in flat-mounted tissue, without the need 
for stereology. Optic nerve transection leads to the apoptotic death of 90% of injured RGCs within 14 days postaxotomy 9-11. RGC apoptosis has a 
characteristic time-course whereby cell death is delayed 3-4 days postaxotomy, after which the cells rapidly degenerate. This provides a time window for 
experimental manipulations directed against pathways involved in apoptosis.

Optic Nerve transection is a widely used model of adult CNS injury. Ninety percent of retinal ganglion cells (RGCs) whose axons are completely transected (axotomy) die within 14 days after axotomy. This model is easily amenable to experimental manipulations and highly reproducible.

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. 
The optic nerve can be ...

Neuroscience

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients &#8804;55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged &#8804;55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve ...

Partial Optic Nerve Transection in Rats: A Model Established with a New Operative Approach to Assess Secondary Degeneration of Retinal Ganglion Cells

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection is considered a useful and reproducible model. Compared with other optic nerve injury models used commonly for assessing secondary degeneration, e.g. complete optic nerve transection and optic nerve crush models, the partial optic nerve transection model is superior as it distinguishes primary from secondary degeneration in situ. Therefore, it serves as an excellent tool for evaluating secondary degeneration. This study describes a novel operative approach of partial optic nerve transection by directly accessing the area of the retrobulbar optic nerve through the orbital lateral wall of the eyeball. Moreover, we present a newly designed, low cost surgical instrument to assist with transection. As demonstrated by the representative results in distinguishing the boundary of primary and secondary injury areas, the new approach and instrument ensures high efficiency and stability of the model by providing adequate space for surgical operation. This in turn makes it easy to separate the meningeal sheath and ophthalmic vessels from the optic nerve before transection. An additional benefit is that this space-saving operative approach improves the investigators&#39; ability to administer drugs, carriers, or selective RGC tracers to the stump of the partially transected optic nerve, allowing the exploration of mechanisms behind secondary injury in RGCs, in a new way.

Secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. This study describes an innovative operative approach for partial optic nerve transection. The use of this space-saving operative approach extends the model's application range, and allows exploration of secondary injury mechanisms in RGCs in a new way.

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection ...

Sheath-Preserving Optic Nerve Transection in Rats to Assess Axon Regeneration and Interventions Targeting the Retinal Ganglion Cell Axon

Retinal ganglion cell (RGC) axons converge at the optic nerve head to convey visual information from the retina to the brain. Pathologies such as glaucoma, trauma, and ischemic optic neuropathies injure RGC axons, disrupt transmission of visual stimuli, and cause vision loss. Animal models simulating RGC axon injury include optic nerve crush and transection paradigms. Each of these models has inherent advantages and disadvantages. An optic nerve crush is generally less severe than a transection and can be used to assay axon regeneration across the lesion site. However, differences in crush force and duration can affect tissue responses, resulting in variable reproducibility and lesion completeness. With optic nerve transection, there is a severe and reproducible injury that completely lesions all axons. However, transecting the optic nerve dramatically alters the blood brain barrier by violating the optic nerve sheath, exposing the optic nerve to the peripheral environment. Moreover, regeneration beyond a transection site cannot be assessed without reapposing the cut nerve ends. Furthermore, distinct degenerative changes and cellular pathways are activated by either a crush or transection injury.
The method described here incorporates the advantages of both optic nerve crush and transection models while mitigating the disadvantages. Hydrostatic pressure delivered into the optic nerve by microinjection completely transects the optic nerve while maintaining the integrity of the optic nerve sheath. The transected optic nerve ends are reapposed to allow for axon regeneration assays. A potential limitation of this method is the inability to visualize the complete transection, a potential source of variability. However, visual confirmation that the visible portion of the optic nerve has been transected is indicative of a complete optic nerve transection with 90-95% success. This method could be applied to assess axon regeneration promoting strategies in a transection model or investigate interventions that target the axonal compartments.

This protocol describes an optic nerve transection that preserves the optic nerve sheath in rats. Hydrostatic pressure from microinjections into the optic nerve generate a complete transection, allowing for sutureless reapposition of the transected optic nerve ends and direct targeting of the axonal compartment in a transection model.

Retinal ganglion cell (RGC) axons converge at the optic nerve head to convey visual information from the retina to the brain. Pathologies such as ...

Transtubular Endoscopic Posterolateral Decompression for L5-S1 Lumbar Lateral Disc Herniation

We report a novel technique for C-arm free transtubular L5 nerve decompression under CT-based navigation to reduce the radiation hazard. This procedure is performed under general anesthesia and neuromonitoring. The patient is placed in a prone position on an operating carbon table. A navigation reference frame is placed percutaneously into the contralateral sacroiliac joint or spinous process. Then, CT scan images are obtained. After instrument registration, the L5-S1 foraminal level is confirmed with a navigated probe, and the entry point is marked. Using an approximately 2 cm skin incision, the subcutaneous tissue and muscles are dissected. The navigated first dilator is aimed at the L5-S1 Kambin&#39;s triangle, and sequential dilation is performed. The 18 mm tube is used and fixed to the frame. The bone around the Kambin&#39;s triangle is removed with a navigated burr. For lateral disc herniation, the L5 nerve root is identified and retracted, and the disc fragment is removed. The navigation-guided tubular endoscopic decompression is an effective procedure. There is no radiation hazard to the surgeon or the operating room staff.

Presented here is a novel technique of C-arm free transtubular posterolateral decompression for lumbar foraminal stenosis and lateral disc herniation under O-arm navigation.

We report a novel technique for C-arm free transtubular L5 nerve decompression under CT-based navigation to reduce the radiation hazard. This procedure is ...

Full-Endoscopic Decompression for Thoracic Ossification of the Ligamentum Flavum Combined with Dural Ossification

Ossification of the ligamentum flavum (OLF) can result in spinal stenosis. Thoracic spinal cord compression due to spinal stenosis is a common cause of progressive thoracic myelopathy in Asian countries. The incidence of complications is high in open decompression surgeries for thoracic OLF. With dural ossification (DO), the risk of complications is even higher in thoracic OLF. We introduce a full-endoscopic decompression surgery for thoracic OLF combined with DO under local anesthesia. Hemilaminectomy is performed using a high-speed burr under the endoscopy first, and then decompression of the contralateral spinal canal is completed using an "over the top" technique. DO resection uses the eggshell technique; after the base of the DO is cut from the lamina, forceps or lamina rongeurs are typically used for removal. The dural defect left after resection does not need repair. Neurological function was improved, and no complications such as hematoma or neck pain occurred. On imaging, no pseudodural cyst, cerebrospinal fluid leakage, or wound complications were observed after the operation. Endoscopic surgery causes less damage to the posterior ligament complex, so no cases of persistent back pain complaints or secondary internal fixation requirements were found in this study. Full-endoscopic decompression can achieve good imaging and clinical effects in the treatment of thoracic OLF with DO.

We describe a minimally invasive surgery using a full-endoscopy system for the single segmental thoracic ossification of the ligamentum flavum, combined with dural ossification, at Hebei General Hospital.

Ossification of the ligamentum flavum (OLF) can result in spinal stenosis. Thoracic spinal cord compression due to spinal stenosis is a common cause of ...

Full-Endoscopic Interlaminar Approach for Decompression of Lateral Recess Stenosis

For lateral recess stenosis, extensive decompression with laminectomy is still performed in most centers. However, tissue-sparing surgeries are becoming more common. Full-endoscopic spinal surgeries have the advantages of being less invasive and offering a shorter recovery time. Here, we describe the technique of the full-endoscopic interlaminar approach for the decompression of lateral recess stenosis. The full-endoscopic interlaminar approach for the lateral recess stenosis procedure took approximately 51 min (range of 39-66 min). Blood loss could not be measured due to continuous irrigation. However, no drainage was required. There were no dura mater injuries reported in our institution. Furthermore, there were no injuries to the nerves, no cauda equine syndrome, and no hematoma formation. The patients were mobilized on the same day as surgery and discharged the next day. Therefore, the full-endoscopic technique for lateral recess stenosis decompression is a feasible procedure that lowers the operational time, complications, traumatization, and rehabilitation duration.

Technical advances and increased experience in full-endoscopic spinal surgeries enable these procedures to be performed with minimal incision, muscle retraction, and bone removal.

For lateral recess stenosis, extensive decompression with laminectomy is still performed in most centers. However, tissue-sparing surgeries are becoming ...

A 3-Channel Endoscopic Technique for Lumbar Stenosis and Contralateral Herniation

The Third Channel-Assisted Unilateral Biportal Endoscopic Technique for Lumbar Spinal Stenosis Combined with Contralateral Disc Herniation

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating lumbar spinal stenosis, particularly in Eastern Asia. The traditional UBE technique, with two portals on one side, can achieve successful unilateral laminotomy for bilateral decompression (ULBD) and, therefore, demonstrates favorable clinical outcomes. However, in the case of lumbar spinal stenosis combined with contralateral disc herniation, it is very difficult to remove the contralateral disc herniation, especially the loose disc fragment within the deep disc. Here, a third channel of the traditional UBE technique was developed to do the discectomy within the ipsilateral endoscopic vision, with which the instruments can go vertically into the contralateral disc, allowing easy discectomy. This technique can not only achieve adequate decompression of the bilateral spinal canal but also effectively remove contralateral herniated disc fragments. This technique avoids performing another UBE procedure on the opposite side, which can potentially shorten the duration of the operation, minimize blood loss and tissue damage, and ensure sufficient neural decompression. This paper will introduce the indications and surgical operation procedures, as well as present a classical case report and follow-up data, to facilitate the application of the third channel-assisted UBE (T-UBE) technique for spine surgeons.

Author Spotlight: Unveiling the Potential of TUBE Technique in Spinal Surgery

Here, we present the third channel-assisted UBE technique, which allows for the vertical removal of herniated disc fragments. This technique can effectively address the limitations of traditional UBE techniques. This article will systematically elaborate on this procedure.

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating ...

Treating Lumbar Spinal Stenosis with a Minimally Invasive Spine Surgery

Percutaneous Endoscopic Unilateral-Approach Bilateral Decompression for Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) involves the narrowing of the spinal canal due to degenerative changes in the vertebral joints, intervertebral discs, and ligaments. LSS encompasses central canal stenosis (CCS), lateral recess stenosis (LRS), and intervertebral foramen stenosis (IFS). The utilization of lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has gained popularity in the treatment of CCS and LRS. This popularity is attributed to the rapid development of endoscopic instruments and the progress of endoscopic philosophy.
In this technical report, a detailed introduction to the steps and key points of LE-ULBD is provided. Simultaneously, a retrospective review of 132 consecutive patients who underwent LE-ULBD for central canal and/or lateral recess stenosis was conducted. The outcomes after more than two years of follow-up were assessed using the visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, and the modified MacNab criteria to evaluate surgical efficacy. All 132 patients underwent LE-ULBD successfully. Among them, 119 patients were rated as "excellent," while 13 patients were rated as "good" based on the modified MacNab criteria during the last follow-up. Incidental dural tears occurred in four cases, but there were no post-operative epidural hematomas or infections. The experience demonstrates that LE-ULBD is a less invasive, effective, and safe approach. It can be considered as an alternative option for treating patients with lumbar central canal stenosis and/or lateral recess stenosis.

Author Spotlight: Scope of LE-ULBD as a Safe, Effective, and Minimally Invasive Approach to Treat Lumbar Spinal Stenosis

The present protocol describes the steps and key points of lumbar endoscopic unilateral laminotomy for bilateral decompression for the treatment of degenerative lumbar spinal stenosis.

Lumbar spinal stenosis (LSS) involves the narrowing of the spinal canal due to degenerative changes in the vertebral joints, intervertebral discs, and ...