3D anatomy of the supraorbital and greater occipital nerve trajectories

PURPOSE

This research aims to enhance understanding of the anatomy of the supraorbital nerve (SON) and greater occipital nerve (GON), focusing on their exit points, distal trajectories, and variability, utilizing a novel 3D representation.

METHODS

Ten cadaveric specimens underwent meticulous dissection, and 3D landmarks were registered. Models were generated from CT scans, and a custom 3D method was employed to visualize nerve trajectories. Measurements, including lengths and distances, were obtained for the SON and GON.

RESULTS

The SON exhibited varied exit points, with the lateral branches being the longest. The GON showed distinct branching patterns, which are described relative to various anatomical reference points and planes. No systematic left-right differences were observed for either nerve. 3D analysis revealed significant interindividual variability in nerve trajectories. The closest approximation between the SON and GON occurred between lateral branches.

CONCLUSION

The study introduces a novel 3D methodology for analyzing the SON and GON, highlighting considerable anatomical variation. Understanding this variability is crucial for clinical applications and tools targeting the skull innervation. The findings serve as a valuable reference for future research, emphasizing the necessity for personalized approaches in innervation-related interventions.

Efficacy of greater occipital nerve block treatment for migraine and potential impact of patient positioning during procedure: Results of randomised controlled trial

PURPOSE

Assess the efficacy, and potential impact of patient positioning for 10 minutes immediately post-procedure, of greater occipital nerve (GON) block for treatment of migraine.

METHODS

Prospective multicentre non-blinded randomised controlled trial, randomisation and treatment of 60 neurology clinic patients with poorly controlled migraine. Outcomes measured with Headache Impact Test-6 (HIT-6), modified MIgraine Disability Assessment Scale (M-MIDAS), and RELIEF scores.

RESULTS

Patient positioning did not lead to significant difference in RELIEF score (34% vs 11%, p-value 0.10, Chi-squared test) at day 90. When considered in a multiple regression analysis, the sitting position outperformed supine position significantly (p-value 0.04). However, no significant difference in HIT-6 score between the supine (n = 27) and sitting position groups (n = 33) was detected at baseline (p-value 0.76), day 30 (p-value 0.69) or day 90 (p-value 0.54, Mann-Whitney U-test). The HIT-6 score significantly improved post-GON block, from median 67 (baseline pre-GON) to 59 (day 30) and 62 (day 90) for the supine group and a score of 66, 61-62 for the sitting group (all p-value ≤ 0.001, intra-group comparison using Wilcoxon test); M-MIDAS achieved similar outcomes. Overall, a significant minimal clinically important improvement was obtained with GON block, and the GON injections were deemed very tolerable by patients (median score of 2 on 10 cm pain scale).

CONCLUSION

Regardless of patient positioning, GON block is an effective and near-painless procedure for migraine symptom control. Unlike earlier published observational study data, this trial concludes that a sitting patient position immediately post-GON is preferred.

The triangular area between the greater, lesser, and third occipital nerves and its possible clinical significance

PURPOSE

Occipital Neuralgia (ON) is defined as a unilateral or bilateral pain in the posterior area of the scalp occurring in the distribution area or areas of the greater occipital nerve (GON), lesser occipital nerve (LON), and/or third occipital nerve (TON). In the present study, the purpose was to show the possible importance of the triangular area (TA) in nerve block applied in ON by measuring the TA between GON, TON, and LON.

METHODS

A total of 24 cadavers (14 males, 10 females) were used in the present study. The suboccipital region was dissected, revealing the points where the GON and TON pierced the trapezius muscle and superficial area, and the point where the LON left the sternocleidomastoid muscle from its posterior edge and was photographed. The area of the triangle between the superficial points of these three nerves and the center of gravity of the triangle (CGT) were determined by using the Image J Software and the results were analyzed statistically.

RESULTS

The mean TA values were 952.82 ± 313.36 mm2 and 667.55 ± 273.82 mm2, respectively in male and female cadavers. Although no statistically significant differences were detected between the sides (p > 0.05), a statistically significant difference was detected between the genders (p < 0.05). The mean CGT value was located approximately 5 cm below and 3-3.5 cm laterally from the external occipital protuberance in both genders and sides.

CONCLUSION

In ON that has more than one occipital nerve involvement, all occipital nerves can be blocked by targeting TA with a single occipital nerve block, and thus, the side effects that may arise from additional blocks can be reduced. The fact that there was a statistically significant difference according to the genders in the TA suggests that different block amounts can be applied according to gender.

Review of craniofacial pain syndromes involving the greater occipital nerve: relevant anatomy, clinical findings, and interventional management

Craniofacial pain syndromes exhibit a high prevalence in the general population, with a subset of patients developing chronic pain that significantly impacts their quality of life and results in substantial disabilities. Anatomical and functional assessments of the greater occipital nerve (GON) have unveiled its implication in numerous craniofacial pain syndromes, notably through the trigeminal-cervical convergence complex. The pathophysiological involvement of the greater occipital nerve in craniofacial pain syndromes, coupled with its accessibility, designates it as the primary target for various interventional procedures in managing craniofacial pain syndromes. This educational review aims to describe multiple craniofacial pain syndromes, elucidate the role of GON in their pathophysiology, detail the relevant anatomy of the greater occipital nerve (including specific intervention sites), highlight the role of imaging in diagnosing craniofacial pain syndromes, and discuss various interventional procedures such as nerve infiltration, ablation, neuromodulation techniques, and surgeries. Imaging is essential in managing these patients, whether for diagnostic or therapeutic purposes. The utilization of image guidance has demonstrated an enhancement in reproducibility, as well as technical and clinical outcomes of interventional procedures. Studies have shown that interventional management of craniofacial pain is effective in treating occipital neuralgia, cervicogenic headaches, cluster headaches, trigeminal neuralgia, and chronic migraines, with a reported efficacy of 60-90% over a duration of 1-9 months. Repeated infiltrations, neuromodulation, or ablation may prove effective in selected cases. Therefore, reassessment of treatment response and efficacy during follow-up is imperative to guide further management and explore alternative treatment options. Optimal utilization of imaging, interventional techniques, and a multidisciplinary team, including radiologists, will ensure maximum benefit for these patients.

The effect of TENS on sleep: A pilot study

BACKGROUND

Insomnia is the second most common neuropsychiatric disorder, but the current treatments are not very effective. There is therefore an urgent need to develop better treatments. Transcutaneous electrical nerve stimulation (TENS) may be a promising means of treating insomnia.

OBJECTIVE

This work aims to explore whether and how TENS modulate sleep and the effect of stimulation waveforms on sleep.

METHODS

Forty-five healthy subjects participated in this study. Electroencephalography (EEG) data were recorded before and after four mode low-frequency (1 Hz) TENS with different waveforms, which were formed by superimposing sine waves of different high frequencies (60-210 Hz) and low frequencies (1-6 Hz). The four waveform modes are formed by combining sine waves of varying frequencies. Mode 1 (M1) consists of a combination of high frequencies (60-110 Hz) and low frequencies (1-6 Hz). Mode 2 (M2) is made up of high frequencies (60-210 Hz) and low frequencies (1-6 Hz). Mode 3 (M3) consists of high frequencies (110-160 Hz) and low frequencies (1-6 Hz), while mode 4 (M4) is composed of high frequencies (160-210 Hz) and low frequencies (1-6 Hz). For M1, M3 and M4, the high frequency portions of the stimulus waveforms account for 50%, while for M2, the high frequency portion of the waveform accounts for 65%. For each mode, the current intensities ranged from 4 mA to 7 mA, with values for each participant adjusted according to individual tolerance. During stimulation, the subjects were stimulated at the greater occipital nerve by the four mode TENS.

RESULTS

M1, M3, and M4 slowed down the frequency of neural activity, broadened the distribution of theta waves, and caused a decrease in activity in wakefulness-related regions and an increase in activity in sleep-related regions. However, M2 has the opposite modulation effect.

CONCLUSION

These results indicated that low-frequency TENS (1 Hz) may facilitate sleep in a waveform-specific manner. Our findings provide new insights into the mechanisms of sleep modulation by TENS and the design of effective insomnia treatments.

Review of evidence

INTRODUCTION

Peripheral nerve blocks have been a common treatment for multiple headaches. By far, the greater occipital nerve block is the most used and with the stronger body of evidence in routine clinical practice.

METHODS

We searched Pubmed Meta-Analysis/Systematic Review, in the last 10 years. Of these results, meta-analyses, and in the absence of these systematic reviews, assessing Greater Occipital Nerve Block in headache has been selected for review.

RESULTS

We identified 95 studies in Pubmed, 13 that met the inclusion criteria.

CONCLUSION

Greater occipital block is an effective and safe technique, easy to perform and which has shown its usefulness in migraine, cluster headache, cervicogenic headache and Post-dural puncture headache. However, more studies are needed to clarify its long-term efficacy, its place in clinical treatment, the possible difference between different anaesthetics, the most convenient dosage and the role of concomitant use of corticosteroids.

Anatomical considerations of cutaneous nerves of scalp for an effective anesthetic blockade for procedures on the scalp

Objective

The anatomy of the scalp nerves varies widely with age, race, and individuals of the same race and even within the same individual and hence need to be studied extensively to avoid complications and improve effectiveness during various surgical and anesthetic procedures of the scalp.

Materials and Methods

Gross dissection was carried out on 11 cadavers (22 Hemifaces: 11 right and 11 left) with no obvious scalp deformities or surgeries. The distances of the supraorbital nerve (SON), supratrochlear nerve (STN), and greater occipital nerve (GON) from commonly used bony landmarks were measured. The branching pattern and presence of accessory notches/foramina were noted.

Results

SON and STN were found almost midway and at the junction between medial and middle one-third of the line joining midline and lateral orbital margin, respectively. The distances of STN and SON from the midline were about ½ and 3/4th of the transverse orbital diameters of the individual. GON was found at the medial 2/5 and lateral 3/5 of the line joining inion to the mastoid. In 40.9% cases, SON gave three branches while STN and GON remained as single trunks in 77.27% and 40.0% cases, respectively. Accessory foramina/notches for SON and STN were found in 36.36% and 4.54% of the specimen, respectively. SON and STN remained lateral in the majority while GON ran medially to corresponding vessels.

Conclusion

These parameters on the Indian population would give a comprehensive idea of the distribution of these cutaneous scalp nerves and would be beneficial in the targeted and accurate deposition of local anesthetic.

Diminishing accelerated long-term forgetting in mild cognitive impairment: Study protocol for a prospective, double-blind, placebo-controlled, randomized controlled trial

Background

Harnessing the lifelong potential of the human brain for neuroplasticity may serve to maintain the viability of neural structures and postpone the onset of cognitive decline. The absence of effective pharmacological interventions to counter memory decline has encouraged scientists to test the possibility that noninvasive electrical stimulation may serve as an additional tool to improve memory abilities.

Previous research showed that electrical stimulation of the greater occipital nerve enhances memory recall performance in young and older healthy subjects. This study aims to extend these findings to determine the effect of transcutaneous electrical stimulation of the greater occipital nerve on the improvement of episodic memory in individuals with amnestic Mild Cognitive Impairment (aMCI).

Methods/design

This study is a prospective, double-blind, placebo-controlled, randomized parallel-group study. A total of 100 individuals with a diagnosis of aMCI according to NIA/AA will be recruited. Participants will be randomly assigned to one of four groups. One group will receive active non-invasive transcutaneous electrical stimulation of greater occipital nerve (NITESGON), while three groups will serve as controls (i.e., sham NITESGON, active NITESGON with local anesthesia, and active NITESGON on the C5/C6 nerve). The primary outcome, i.e., memory recall, will be determined by a word association task, and will be recorded at baseline, 7 days after NITESGON, and 28 days after NITESGON. The secondary outcome is neurophysiological changes determined by resting state EEG and will be assessed immediately before and after NITESGON.

Discussion

The results will add new insights into improving episodic memory in individuals with aMCI.

Trial registration

#NCT05289804 (clinicaltrial.gov)

Protocol approval id

#SPREC102021-23 (Ethics Committee at Trinity College Dublin, School of Psychology)

Single midline incision approach for decompression of greater, lesser and third occipital nerves in migraine surgery

Background

The traditional approach for occipital migraine surgery encompasses three separate surgical incisions in the posterior neck to decompress the greater occipital nerves (GON), lesser occipital nerves (LON), and third occipital nerves (TON). Other incisions have been investigated, including singular transverse incisions. We sought to evaluate a single, vertical midline incision approach for decompression of all six occipital nerves.

Methods

Using 10 cadaveric hemi-sides (5 fresh cadaver head and necks). Anatomic landmarks and the location of the bilateral GON, LON, and TON were marked according to previous anatomic studies. A single, midline 9-cm incision was made, and lateral skin flaps were raised to decompress or avulse all six nerves.

Results

Through the midline incision, the GON and TON were identified at 3.5 and 6.2 cm, respectively, inferior to a line bisecting the external auditory canal (EAC) and 1.5 cm lateral to the midline. The LON was identified as 6-cm inferior and 6.5-cm medial to a line bisecting the EAC in the plane just above the investing layer of the deep cervical fascia until the posterior border of the sternocleidomastoid was encountered. The LON had the greatest amount of variation but was identified lateral to the posterior border of the SCM.

Conclusions

A single midline incision approach allows for successful identification and decompression of all six occipital nerves in migraine surgery.

Anatomy of the greater occipital nerve: implications in posterior fossa approaches

PURPOSE

Because of its superficial location in the dorsal regions of the scalp, the greater occipital nerve (GON) can be injured during neurosurgical procedures, resulting in post-operative pain and postural disturbances. The aim of this work is to specify the course of the GON and how its injuries can be avoided while performing posterior fossa approaches.

METHODS

This study was carried out at the department of anatomy at Bordeaux University. 4 specimens were dissected to study the GON course. Posterior fossa approaches (midline suboccipital, paramedian suboccipital, retrosigmoid and petrosal) were performed on 4 other specimens to assess potential risks of GON injuries.

RESULTS

The GON runs around the obliquus capitis inferior (100%), crosses the semispinalis capitis (100%) and the trapezius (75%) or its aponeurosis (25%). Direct GON injuries can be seen in paramedian suboccipital approaches. Stretching of the GON can occur in midline suboccipital and paramedian suboccipital approaches. We found no evidence of direct or indirect GON injury in retrosigmoid or petrosal approaches.

CONCLUSION

Our study provides interesting data regarding the risk GON injury in posterior fossa approaches. Direct GON injuries in paramedian suboccipital approaches can be avoided with careful dissection. Placing retractors in contact with the periosteum and performing a minimal retraction may help to avoid excessive GON stretching in midline suboccipital and paramedian suboccipital approaches. Furthermore, the incision for retrosigmoid approaches should be as lateral as possible and not too caudal. Finally, avoiding extreme patient positioning reduces the risk of GON stretching in all approaches.

Greater occipital nerve blockade using ultrasound guidance for the headache of spontaneous intracranial hypotension - A case report

Background

Spontaneous intracranial hypotension occurs due to cerebrospinal fluid leakage from the spinal column, and orthostatic headache is the most common clinical presentation. Recent studies showed that bilateral greater occipital nerve blockade demonstrated clinical efficacy in relieving post-dural puncture headache after caesarean section.

Case

A 40-year-old male who presented severe orthostatic headache was consulted to our pain clinic from neurology department. He initially felt a dull nature pain over the whole occipital area which then spread over the frontal and parietal areas. His headache was combined with nausea and vomiting. An epidural blood patch was delayed until final cisternography, and bilateral greater occipital nerve blockade using ultrasound guidance was performed instead. After the blockade, the previously existing headache around the occipital and parietal areas disappeared completely, but mild headache persisted around the frontal area.

Conclusions

Greater occipital nerve blockade could be a good therapeutic alternative to improve headache resulting from spontaneous intracranial hypotension.

Decompression of the Greater Occipital Nerve for Persistent Headache Attributed to Whiplash Accompanying Referred Facial Trigeminal Pain

OBJECTIVE

Persistent headache attributed to whiplash (PHAW) is defined as a headache that occurs for the first time in close temporal relation to whiplash lasting more than 3 months. We investigated the results of decompression of the greater occipital nerve (GON) in patients with PHAW who presented with referred trigeminal facial pain caused by sensitization of the trigeminocervical complex) along with occipital headache.

METHODS

A 1-year follow-up study of GON decompression was conducted in 7 patients with PHAW manifesting referred facial trigeminal pain. The degree of pain reduction was analyzed using the numeric rating scale (NRS-11) and percent pain relief before and 1 year after surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Clinical characteristics of headache and facial pain and surgical findings were studied.

RESULTS

GON decompression was effective in all 7 patients with PHAW manifesting referred trigeminal pain, with a percent pain relief of 83.06 ± 17.30. The pain had disappeared in 3 of 7 patients (42.9%) within 6 months and no further treatment was needed. Patients' assessment of subjective improvement based on a 10-point Likert scale was 7.23 ± 1.25. It was effective in both occipital and facial pain.

CONCLUSIONS

Although chronic GON entrapment itself is an individual constitutional issue, postwhiplash inflammatory changes seem to trigger chronic occipital headaches in GON distribution and unexplained referred trigeminal pain caused by sensitization of the trigeminocervical complex.

Latent class cluster analysis identified hidden headache phenotypes in COVID-19: impact of pulmonary infiltration and IL-6

Background and objective

Clinical studies on COVID-19 headache are limited. This prospective study aimed to define headache characteristics, associated clinical and laboratory factors, and treatment response in COVID-19.

Methods

Cross-sectional study enrolled 287 patients diagnosed with COVID-19 and hospitalized on a regular ward during the pandemic. All patients were examined face to face and followed by a neurologist during their stay in the hospital. The characteristics, concomitant symptoms, treatment responses, and laboratory findings of COVID-19-associated headaches were recorded.

Results

Eighty-three COVID-19 patients reported headache (28.9%), in which 85.5% had no prior headaches. Mean age was 48.40 ± 15.90 and 58% was men. Compared to COVID-19 patients without headache (n = 204), patients with headache showed significantly higher frequency of pulmonary involvement (76%) and increased D-dimer levels. Fifty-nine percent of headaches responded iv paracetamol 1000 mg, and 85% of the paracetamol unresponsive headaches were relieved by greater occipital nerve (GON) blocks. Latent class cluster analysis identified 2 distinct class of bilateral, frontal, throbbing headaches: severe (VAS > 84), longer (> 14 h), frequent (> 7 headache days), paracetamol unresponsive-GON responsive headaches (85%), with pulmonary involvement (100%), and higher IL-6 levels (> 90 pg/mL) were classified in cluster 1. Cluster 2 included moderately affected patients (VAS > 54, > 6 h, > 4 days, 60% pulmonary involvement, > 20 pg/mL IL-6) and paracetamol responsive headaches (96%). VAS scores showed positive linear correlation with IL-6 levels (p < 0.001; r = 0.567).

Conclusion

The intensity, duration, frequency, bilateral frontal location, and treatment response of COVID-19 headache was related to pulmonary involvement and IL-6 levels, which indicated a role of inflammation in determining the headache manifestations in moderately affected hospitalized patients. ROC curve cutoff values pointed that VAS > 70 severity, > 9 h duration, > 5 headache days, and IL-6 > 43 pg/mL levels can be diagnostic for COVID-19 headache. GON blocks can effectively abort headache when patients are unresponsive to paracetamol, and other NSAIDs are avoided during the SARS-CoV-2 infection.

Decompression of the greater occipital nerve improves outcome in patients with chronic headache and neck pain - a retrospective cohort study

BACKGROUND

Compression of the greater occipital nerve (GON) may contribute to chronic headache, neck pain, and migraine in a subset of patients. We aimed to evaluate whether GON decompression could reduce pain and improve quality of life in patients with occipital neuralgia and chronic headache and neck pain.

METHODS

In this retrospective cohort study, selected patients with neck pain and headache referred to a single neurosurgical center were analyzed. Patients (n = 22) with suspected GON neuralgia based on nerve block or clinical criteria were included. All patients presented with occipital pain spreading frontally and to the neck in various degree. Surgical decompression was performed under local anesthesia. Follow-up was made by an assessor not involved in the treatment of the patients, by telephone 2-5 years after the surgical procedure and an interview protocol was used to collect information. The data from the follow-up protocols were then analyzed and reported.

RESULTS

When analyzing the follow-up protocols, decreased headache/migraine was reported in 77% and neck pain was reduced in 55% of the patients.

CONCLUSIONS

Decompression of GON(s) may reduce neck pain and headache in selected patients with persistent headache, neck pain, and clinical signs of GON neuralgia. Based on the limitations of the present retrospective study, the results should be considered with caution.

Increased mechanosensivity of the greater occipital nerve in subjects with side-dominant head and neck pain - a diagnostic case-control study

Objectives: To investigate differences in pressure pain thresholds (PPTs) and longitudinal mechanosensitivity of the greater occipital nerve (GON) between patients with side-dominant head and neck pain (SDHNP) and healthy controls. Evaluation of neural sensitivity is not a standard procedure in the physical examination of headache patients but may influence treatment decisions. Methods: Two blinded investigators evaluated PPTs on two different locations bilaterally over the GON as well as the occipitalis longsitting-slump (OLSS) in subjects with SDHNP (n = 38)) and healthy controls (n = 38). Results: Pressure pain sensitivity of the GON was lower at the occiput in patients compared to controls (p = 0.001). Differences in pressure sensitivity of the GON at the nucheal line, or between the dominant headache side and the non-dominant side were not found (p > 0.05). The OLSS showed significant higher pain intensity in SDHNP (p < 0.001). In comparison to the non-dominant side, the dominant side was significantly more sensitive (p = 0.004). Discussion: Palpation of the GON at the occiput and the OLSS may be potentially relevant tests in SDHNP. One explanation for an increased bilateral sensitivity may be sensitization mechanisms. Future research should investigate the efficacy of neurodynamic techniques directed at the GON. Level of Evidence: 3b.

Efficacy of bilateral greater occipital nerve block in postdural puncture headache: a narrative review

The Epidural blood patch is considered the gold standard for managing postdural puncture headache when supportive measures fail. However, it is a procedure which can lead to another inadvertent dural puncture. Other potential adverse events that could occur during a blood patch are meningitis, neurological deficits, and unconsciousness. The bilateral greater occipital nerve block has been used for treating chronic headaches in patients with PDPH with a single injection. This minimally invasive, simple procedure can be considered for patients early, along with other supportive treatment, and an epidural blood patch can be avoided.

Greater occipital nerve MR tractography: Feasibility and anatomical considerations

BACKGROUND AND PURPOSE

To assess the feasibility of greater occipital nerve (GON) tractography using a fully automated tractography technique on the whole-neck volume, in comparison with anatomical knowledge.

METHODS

Healthy subjects were consecutively included in this study if they had no history or symptoms of headache or brain disorder. A 3T MRI scanner with a 32 channel head coil was used. The following parameters for Diffusion Weighed (DWI) were used: b value of 1000 s/mm², 32 directions, acquired voxel size: 2 mm isotropic. High-Order tractography with the Constrained Spherical Deconvolution (CSD) model was generated. Track-Weighted Imaging (TWI) maps were generated with MRTrix. Two radiologists performed blind evaluations of the GON pathways on TWI maps.

RESULTS

A total of 20 healthy subjects were included (12 males and eight females, mean age 53.8 years old). In comparison with anatomical atlas, GON complete visualization (from C1-C2 origin to muscular emergence) was possible in 18 out of 20 healthy subjects. In two cases, GON was not visible in the cervical spine foramen.

CONCLUSION

Tractography through TWI is a feasible technique to accurately depict GON. This technique may appear as a promising technique for therapeutic management of patients with occipital neuralgia.

Greater occipital nerve blocks in the treatment of refractory chronic migraine: An observational report of nine cases

AIM

To report the effects of greater occipital nerve (GON) blocks on refractory chronic migraine headache.

METHODS

Nine patients who were receiving the conventionally accepted preventive therapies underwent treatment with repeated GON block to control chronic migraine resistant to other treatments. GON blocking with lidocaine and normal saline mixture was administered by the same physician at hospital once a month (for three times in total). Patients were assessed before the injection and every month thereafter for pain frequency and severity, number of times analgesics were used and any appearant side effects during a 6 mo follow-up.

RESULTS

Eight of nine patients reported a marked decrease in frequency and severity of migraine attacks in comparison to their baseline symptoms; one reported no significant change (not more than 50%) from baseline and did not accept the second injection. GON block resulted in considerable reduction in pain frequency and severity and need to use analgesics up to three months after the injection in the present cases. The patients did not report any adverse effects.

CONCLUSION

Hereby we noticed a remarkable success with refractory chronic migraine patients. We believe that this intervention can result in rapid relief of pain with the effects lasting for perhaps several weeks or even months. Further controlled clinical trials are warranted to evaluate the effect of GON block in the treatment of refractory migraine cases.

Ultrasound-Guided Bilateral Greater Occipital Nerve Block for Mass Excision

Anaesthesiologists must always prefer the safest method to minimize the risk for patients. At present, ultrasound-guided blockage of the greater occipital nerve can be performed in a safe manner. In this report, we presented our experience of ultrasound-guided blockage of the greater occipital nerve that we performed in a patient with a mass at the back of the neck who had risk of general anaesthesia because of comorbidities.

Ultrasound-guided bilateral greater occipital nerve block for the treatment of post-dural puncture headache

Background and Objective:

Post-dural puncture headache (PDPH) is one of the complications frequently observed after spinal or epidural anesthesia with dural penetration. For PDPH patients who do not respond to conservative medical treatment, alternative treatments such as bilateral occipital nerve block should be considered.In this study the efficacy of bilateral occipital nerve block was retrospectively evaluated in patients with post-dural puncture headache.

Methods:

Ultrasound-guided bilateral occipital nerve block was administrated in 21 patients who developed PDPH after spinal anesthesia, but did not respond to conservative medical treatment within 48 hours between January 2012 and February 2014. The study was conducted at Erzincan University Faculty of Medicine Gazi Mengucek Education and Research Hospital

Results:

Mean Visual Analog Scale (VAS) pain scores at 10 minutes and 6, 10, 15 and 24 hours after the block were significantly improved compared to the patients with a pre-block VAS score between 4 and 6 as well as patients with a pre-block VAS score between 7 and 9 (p<0.01). After 24 hours of the block applied, VAS pain score dropped to 1 for all 12 patients who had a pre-block VAS score between 4 and 6. Whereas, VAS score decreased to 2 at 24 hours after the block in only one of the patients with a pre-block VAS between 7 and 9. For the patients with a pre-block VAS score between 7 and 9, there was no significant improvement in the mean VAS score 24 hours after the block.

Conclusions:

For patients with PDPH and a pre-block VAS score between 4 and 6 who do not respond to conservative medical treatment, an ultrasound-guided bilateral occipital nerve block may be effective.

Sensory complications in patients after scalp mass excision and its anatomical considerations

OBJECTIVE

To evaluate the incidence of postsurgical sensory complications in patients with scalp masses and classify the locations of them from a surgical standpoint according to anatomical considerations.

METHODS

A total of 121 patients who underwent surgery for scalp mass were included in this study. The authors reviewed medical records and preoperative radiologic images. We investigated the complications related to sensory changes after procedure. Enrolled patients have been divided into three groups. Group A included patients with tumors above the superior nuchal line (SNL), Group B with tumors within the trapezius muscle area and patients who had tumors on the lateral trapezius muscle area were assigned to Group C. We compared the incidence related to postoperative sensory complications and summarized their additional treatments for these with clinical outcome.

RESULTS

There were 12 patients (10%) with sensory complications related on the mass excision site (Group A: 1 patient, Group B: 2 patients, Group C: 9 patients). Six patients were affected with lesser occipital nerve (LON), 2 patients on greater occipital nerve (GON) and 4 patients on GON and LON. Over 6 months after surgery, two of the twelve patients with sensory complications did not have complete recovered pain in spite of proper medications and local chemical neurolysis with 1.0% lidocaine and dexamethasone.

CONCLUSION

Occipital neuropathy should be considered as a complication related excision of scalp mass. The sensory complications are more frequent in Group C because of the anatomical characteristics of the occipital nerves and there were no statistical difference for other variables.

Intractable occipital neuralgia caused by an entrapment in the semispinalis capitis

Occipital neuralgia is a rare pain syndrome characterized by periodic lancinating pain involving the occipital nerve complex. We present a unique case of entrapment of the greater occipital nerve (GON) within the semispinalis capitis, which was thought to be the cause of occipital neuralgia. A 66-year-old woman with refractory left occipital neuralgia revealed an abnormally low-loop of the left posterior inferior cerebellar artery on the magnetic resonance imaging, suggesting possible vascular compression of the upper cervical roots. During exploration, however, the GON was found to be entrapped at the perforation site of the semispinalis capitis. There was no other compression of the GON or of C1 and C2 dorsal roots in their intracranial course. Postoperatively, the patient experienced almost complete relief of typical neuralgic pain. Although occipital neuralgia has been reported to occur by stretching of the GON by inferior oblique muscle or C1-C2 arthrosis, peripheral compression in the transmuscular course of the GON in the semispinalis capitis as a cause of refractory occipital neuralgia has not been reported and this should be considered when assessing surgical options for refractory occipital neuralgia.