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Update: Microvascular decompression for glossopharyngeal neuralgia

Microvascular decompression for glossopharyngeal neuralgia

For glossopharyngeal neuralgia treatment, should pharmacologic management be ineffective, surgical intervention is indicated. The first-choice treatment is typically microvascular decompression (MVD), as it has the highest initial and long-term success rates.

In 1932, Walter Edward Dandy 1) thought that the operative approach of GPN was the same with trigeminal neuralgia or Meniere’s disease.

Laha and Jannetta 2) proposed that GPN could be treated by surgically relieving the pressure that offending vascular structures imposed on the glossopharyngeal nerves.

Resnick et al. 3) reporteded excellent postoperative surgical results for 79%.

Patel et al. reported in 217 a immediate success rate of 90% 4).

There are three types of neurovascular compression (NVC): type I – NVC at the root entry zone (REZ) of the IX CN within the retro-olivary sulcus; type II – the vertebral artery causes NVC at the IX CN REZ by the shoulder of the artery, and the type III – a “sandwich-like” compression where the vertebral artery and the PICA perform a combination of NVC 5).

Technique

Once the anesthetic induction and intubation have been performed, the patient should be positioned in lateral decubitus fashion, fixing the head with a Mayfield head clamp, followed by the placement of an axillary roll. The neck should be narrowed with slight flexion and rotated approximately 10 degrees to the affected side. The vertex is tilted 15 degrees toward the floor. The shoulder is pulled out of the way and finally the patient is accommodated in such a way that the table can be rotated laterally or adjusted for a Trendelenburg position or reverse Trendelenburg position. For the incision, the mastoid eminence is initially demarcated, then a line is drawn from the external auditory canal to the inion to mark the transverse sinus. Then, a 3-4 cm arcuate or linear incision is performed, with the concave side toward the ear. Half of the incision should be above the mastoid notch or even more posteriorly in large, muscular or dolichocephalic patients. Subsequently, a retractor is placed and the bone is opened with a perforator, making sure to use bone wax in case of bleeding and filling the mastoid cells.

Ordónez-Rubiano et al. propose to target the opening of the bone depending on the CN affected. Three different approaches could be performed. The superior for the V CN (mini extreme-lateral or microasterional), the middle for VII and VIII CNs (usual for the cerebellopontine angle), and the inferior for the IX to XII CNs (mini far-lateral).

Once the dura is exposed, it is incised and stretched. The form in which the dura is opened includes the L or reverse L shape, 3-5 mm parallel to the sigmoid sinus and to the floor of the posterior fossa, after which they are secured with sutures for a wider exposure. A retractor is placed under the cerebellum and raised from its inferolateral margin, after which the microscope is introduced, and the retractor is advanced anteriorly until the spinal part of the XI CN is observed, the arachnoid is dissected, which allows to elevate the cerebellum and expose the remaining CNs within the jugular foramen. Once the rootlets of the IX CN are identified, they are separated from the rootlets of the X and XI CNs. The involved vessel is identified and dissected before the decompression and finally, the Teflon is placed between the two structures 6).

If there is no NVC, the glossopharyngeal nerve and the upper bundle of the X CN can be sectioned 7).

Case series

2018

Between 2006 and 2016, 228 idiopathic GPN patients underwent MVD in our department. Those cases were retrospectively reviewed with emphasis on intraoperative findings and long-term postoperative outcomes. The average period of follow-up was 54.3 ± 6.2 months.

Intraoperatively, the culprit was identified as the posterior inferior cerebellar artery (PICA) in 165 cases (72.3%), the vertebral artery (VA) in 14 (6.1%), vein in 10 (4.4%), and a combination of multiple arteries or venous offending vessels in 39 (17.2%). The immediately postoperative outcome was excellent in 204 cases (89.5%), good in 12 (5.3%), fair in 6 (2.6%) and poor in 6 (2.6%). More than 5-year follow-up was obtained in 107 cases (46.9%), which presented as excellent in 93 (86.9%), good in 6 (5.6%), fair in 3 (2.8%) and poor in 5 (4.7%). Thirty-seven (16.2%) of the patients experienced some postoperative neurological deficits immediately, such as dysphagia, hoarseness and facial paralysis, which has been improved at the last follow-up in most cases, except 2.

This investigation demonstrated that MVD is a safe and effective remedy for treatment of GPN 8).

2017

30 patients with intractable primary typical GPN who underwent MVD without rhizotomy and were followed for more than 2 years were included in the analysis. Each MVD was performed using one of four different surgical techniques: interposition of Teflon pieces, transposition of offending vessels using Teflon pieces, transposition of offending vessels using a fibrin-glue-coated Teflon sling, and removal of offending veins.

The posterior inferior cerebellar artery was responsible for neurovascular compression in 27 of 30 (90%) patients, either by itself or in combination with other vessels. The location of compression on the glossopharyngeal nerve varied; the root entry zone (REZ) only (63.3%) was most common, followed by both the REZ and distal portion (26.7%) and the distal portion alone (10.0%). In terms of detailed surgical techniques during MVD, the offending vessels were transposed in 24 (80%) patients, either using additional insulation, offered by Teflon pieces (15 patients), or using a fibrin glue-coated Teflon sling (9 patients). Simple insertion of Teflon pieces and removal of a small vein were also performed in five and one patient, respectively. During the 2 years following MVD, 29 of 30 (96.7%) patients were asymptomatic or experienced only occasional pain that did not require medication. Temporary hemodynamic instability occurred in two patients during MVD, and seven patients experienced transient postoperative complications. Neither persistent morbidity nor mortality was reported.

This study demonstrates that MVD without rhizotomy is a safe and effective treatment option for GPN 9).


From January 2004 to June 2006, 35 consecutive patients were diagnosed with GPN. All of them underwent MVD. Demographic data, clinical presentation, operative findings, clinical results, operative complications were reviewed.

A total of 33 patients (94.3%) experienced complete pain relief immediately after MVD. Long-term follow-up was available for 30 of these 35 patients, and 28 of these 30 patients continued to be pain-free. There was no long-term operative morbidity in all cases. One patient had a cerebrospinal fluid leak and 1 case presented with delayed facial palsy.

Classic GPN is usually caused by pulsatile neurovascular compression of the glossopharyngeal and vagus rootlets. MVD is a safe, effective, and durable operation for GPN 10).

2015

A retrospective review of the case notes of patients who had undergone surgery for GPN in the authors’ department between 2008 and 2013 was performed to investigate baseline characteristics and immediate outcomes during the hospitalization. For the long-term results, a telephone survey was performed, and information on pain recurrence and permanent complications was collected. Pain relief meant no pain or medication, any pain persisting after surgery was considered to be treatment failure, and any pain returning during the follow-up period was considered to be pain recurrence. For comparative study, the patients were divided into 2 cohorts, that is, patients treated with GPNR alone and those treated with GPNR+VNR.

One hundred three procedures, consisting of GPNR alone in 38 cases and GPNR+VNR in 65 cases, were performed in 103 consecutive patients with GPN. Seventy-nine of the 103 patients could be contacted for the follow-up study, with a mean follow-up duration of 2.73 years (range 1 month-5.75 years). While there were similar results (GPNR vs GPNR+VNR) in immediate pain relief rates (94.7% vs 93.8%), immediate complication rates (7.9% vs 4.6%), and long-term pain relief rates (92.3% vs 94.3%) between the 2 cohorts, a great difference was seen in long-term complications (3.8% vs 35.8%). The long-term complication rate for the combined GPNR+VNR cohort was 9.4 times higher than that in the GPNR cohort. There was no operative or perioperative mortality. Immediate complications occurred in 6 cases, consisting of poor wound healing in 3 cases, and CSF leakage, hoarseness, and dystaxia in 1 case each. Permanent complications occurred in 20 patients (25.3%) and included cough while drinking in 10 patients, pharyngeal discomfort in 8 patients, and hoarseness and dysphagia in 1 case each.

In general, this study indicates that GPNR alone or in combination with VNR is a safe, simple, and effective treatment option for GPN. It may be especially valuable for patients who are not suitable for the microvascular decompression (MVD) procedure and for surgeons who have little experience with MVD. Of note, this study renews the significance of GPNR alone, which, the authors believe, is at least valuable for a subgroup of GPN patients, with significantly fewer long-term complications than those for rhizotomy for both glossopharyngeal nerve and rootlets of the vagus nerve 11).

2002

Patel et al. present the experience with more than 200 patients and conducted a retrospective review of the database and identified patients who presented for treatment of presumed GPN. When possible, patients were contacted by telephone for collection of follow-up information regarding symptom relief, complications, functional outcomes, and patient satisfaction. Univariate and multivariate analyses were performed to identify predictors of good outcomes after MVD. Subgroup analyses were performed with quartiles of approximately 50 patients each, for assessment of the effects of improvements in techniques and anesthesia during this 20-year period.

They observed GPN to be more common among female (66.8%) than male (33.2%) patients, with an overall mean patient age of 50.2 years (standard deviation, 14.4 yr). The most common presenting symptoms were throat and ear pain and throat pain alone, and the mean duration of symptoms was 5.7 years (standard deviation, 5.8 yr; range, 1-32 yr). Symptoms appeared almost equally on the left side (54.8%) and the right side (45.2%). The overall immediate success rate exceeded 90%, and long-term patient outcomes and satisfaction were best for the typical GPN group (with pain restricted to the throat and palate). Complication rates decreased across quartiles for all categories evaluated.

MVD is a safe, effective form of therapy for GPN. It may be most beneficial for patients with typical GPN, especially when symptoms are restricted to deep throat pain only 12).

1995

Since 1971, 40 patients have undergone microvascular decompression of the glossopharyngeal and vagus nerves for treatment of typical glossopharyngeal neuralgia. This procedure provided excellent immediate results (complete or > 95% relief of pain) in 79%, with an additional 10% having a substantial (> 50%) reduction in pain. Long-term follow-up (mean, 48 mo; range, 6-170 mo) reveals excellent results (complete or > 95% reduction in pain without any medication) in 76% of the patients and substantial improvement in an additional 16%. There were two deaths at surgery (5%) both occurring early in the series as the result of hemodynamic lability causing intracranial hemorrhage. Three patients (8%) suffered permanent 9th nerve palsy 13).

1986

20 patients who had undergone microvascular decompression for the treatment of “idiopathic” trigeminal neuralgia (9 cases), hemifacial spasm (7 cases), glossopharyngeal neuralgia (3 cases) and paroxysmal vertigo and tinnitus (1 case) were followed up for 25 months on average. Permanent relief of symptoms was observed in 19 (95%), with sparing of cranial nerve function. Analysis of the clinical data shows that the patients described in the present series did not differ from those considered to suffer from “idiopathic” cranial nerve dysfunction syndromes. The importance of vascular cross compression as etiological factor in such conditions is stressed and the pathophysiology discussed. The term “cryptogenic” applied to trigeminal neuralgia or hemifacial spasm thus needs revising. Lastly, the indications of microvascular decompression in the treatment of “cryptogenic” cranial nerve dysfunction syndromes are defined 14).

1977

Microsurgical observations werw made of the cranial nerve root entry or exit zones 117 patients operated upon for the treatment of hyperactive-hypoactive dysfunction syndromes (trigeminal neuralgia, hemifacial spasm, acoustic nerve dysfunction, and glossopharyngeal neuralgia). Cross-compression or distortion of the appropriate nerve root at its entry or exit zone was noted in all patients. This compression or distortion was usually caused by normal or arteriosclerotic, elongated arterial loops, it was usually relieved by decompressive microsurgical techniques. A small percentage of patients were found to have compression of the nerve root at the entry-exit zone by a tumor, a vein, or some other structural abnormality; they were relieved by tumor excision or other measures as described. Relief was gradual postoperatively if the treated nerve was not stroked or manipulated at operation but it was immediate if the nerve was manipulated. Preoperative evidence of decreased nerve function improved postoperatively 15).

Case reports

A case of coexistent glossopharyngeal neuralgia and hemifacial spasm was treated by transposition of the vertebral artery. A 60-year-old man was referred to our hospital due to pain in the left posterior part of the tongue that was difficult to control with oral medication at a local hospital. The diagnosis was left glossopharyngeal neuralgia based on the symptoms, imaging findings, and lidocaine test results. Moreover, the patient had left hemifacial spasm. Microvascular decompression was performed, which confirmed that the vertebral artery was compressing the lower cranial nerve and the posterior inferior cerebellar artery was compressing the root exit zone of the facial nerve. The vertebral artery and posterior inferior cerebellar artery were transposed using TachoSil. After the surgery, both glossopharyngeal neuralgia and hemifacial spasm disappeared, and the patient was discharged 16).

1985

A case of combined trigeminal and glossopharyngeal neuralgia is described. The superior cerebellar artery and normal choroid plexus compressed and indented the root entry zones of the trigeminal and glossopharyngeal nerves, respectively. Complete relief was obtained after microvascular decompression and resection of the choroid plexus 17).


A case of glossopharyngeal neuralgia associated with episodic cardiac arrest and syncope is presented. Posterior fossa exploration showed that the left glossopharyngeal and vagus nerves were compressed by the posterior inferior cerebellar artery. Microvascular decompression resulted in complete relief of glossopharyngeal neuralgia, cardiac syncope, and seizure. The mechanism of glossopharyngeal neuralgia associated with cardiac syncope is discussed 18).


Murasawa A, Yamada K, Hayakawa T, Aragaki Y, Yoshimine T. Glossopharyngeal neuralgia treated by microvascular decompression–case report. Neurol Med Chir (Tokyo). 1985 Jul;25(7):551-3. PubMed PMID: 2415848 19).

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Laha RK, Jannetta PJ (1977) Glossopharyngeal neuralgia. J Neurosurg 47:316–320
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Kim MK, Park JS, Ahn YH. Microvascular Decompression for Glossopharyngeal Neuralgia: Clinical Analyses of 30 Cases. J Korean Neurosurg Soc. 2017 Nov;60(6):738-748. doi: 10.3340/jkns.2017.0506.010. Epub 2017 Oct 25. PubMed PMID: 29142635; PubMed Central PMCID: PMC5678068.
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Zhao H, Zhang X, Zhu J, Tang YD, Li ST. Microvascular Decompression for Glossopharyngeal Neuralgia: Long-Term Follow-Up. World Neurosurg. 2017 Jun;102:151-156. doi: 10.1016/j.wneu.2017.02.106. Epub 2017 Mar 2. PubMed PMID: 28263933.
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Jannetta PJ. Observations on the etiology of trigeminal neuralgia, hemifacial spasm, acoustic nerve dysfunction and glossopharyngeal neuralgia. Definitive microsurgical treatment and results in 117 patients. Neurochirurgia (Stuttg). 1977 Sep;20(5):145-54. PubMed PMID: 198692.
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Fujii T, Otani N, Otsuka Y, Matsumoto T, Tanoue S, Ueno H, Tomura S, Tomiyama A, Toyooka T, Wada K, Mori K. [A Case of Coexistent Glossopharyngeal Neuralgia and Hemifacial Spasm Successfully Treated with Transposition of the Vertebral Artery]. No Shinkei Geka. 2017 Jun;45(6):503-508. doi: 10.11477/mf.1436203540. Review. Japanese. PubMed PMID: 28634310.
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Update: Superior semicircular canal dehiscence

Superior semicircular canal dehiscence

Superior semicircular canal dehiscence (SSCD) is a disorder of the skull base that is gaining increasing recognition among neurosurgeons.

Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrous temporal bone.

With this dehiscence, the fluid in the membranous superior canal (which is located within the tubular cavity of the bony canal) can be displaced by sound and pressure stimuli, creating certain vestibular and/or auditory signs and symptoms.

Since this was first reported in 1998 by Minor and colleagues, there has been much advancement made in terms of diagnosis and treatment 1).

Diagnosis

The condition is confirmed on high-resolution computed tomography (CT) imaging.

High-resolution computed tomographic temporal bone images were imported into a freely available segmentation software. Dehiscence lengths and volumes were ascertained by independent authors. Inter-rater observer reliability was assessed using Cronbach’s alpha. Correlation and regression analyses were performed to evaluate for relationships between dehiscence size and symptoms (pre- and post-operative).

Thirty-seven dehiscences were segmented using the novel volumetric assessment. Cronbach’s alpha for dehiscence lengths and volumes were 0.97 and 0.95, respectively. Dehiscence lengths were more variable as compared to dehiscence volumes (σ 2 8.92 vs σ 2 0.55, F = 1.74). The mean dehiscence volume was 2.22 mm 3 (0.74, 0.64-0.53 mm 3 ). Dehiscence volume and headache at presentation were positively correlated ( R pb = 0.67, P = .03). Dehiscence volume and vertigo improvement after surgery were positively correlated, although this did not reach statistical significance ( R pb = 0.46, P = .21).

SSCD volumetry is a novel method of measuring dehiscence size that has excellent inter-rater reliability and is less variable compared to dehiscence length, but its potential as a predictor of symptom outcomes is not substantiated. However, the study is limited by low power 2).

MRI FIESTA scans have recently been used to image SSCD. Additionally, audiometry and vestibular evoked myogenic potential (VEMP) testing are useful screening tools.

Treatment

Currently, the middle fossa approach is the most common and standard surgical approach to repair SSCD. The transmastoid, endoscopic and transcanal or endaural approaches have also been recently utilized. Presently, there is no consensus as to the best approach, material or technique for repair of SSCD. As we learn more, newer and less invasive approaches and techniques are being used to treat SSCD 3).

Symptoms are often improved by surgical repair. Although a classic middle fossa craniotomy has been used with good results, recent advances in technique have allowed for modification of the traditional approach into a smaller skin incision and a minimally invasive middle fossa keyhole craniectomy roughly 1.7 cm in diameter.

To delineate this novel approach and describe the technique for accurate localization of the dehiscence using preoperative measurements and intraoperative image guidance, thereby minimizing the need for a larger skin incision and craniotomy.

Patients were independently diagnosed with SSCD by the senior authors. Once relevant imaging was acquired, the novel keyhole technique was performed. Patients’ vestibular and auditory symptoms before and after the procedure were assessed. Outcomes from a series of patients treated with this keyhole approach were tabulated and reported.

Twelve cases from 11 patients were included in this series. Auditory symptoms had high rates of resolution with pulsatile tinnitus, internal amplification of sounds, and autophony being resolved in a majority of cases. Only 2 cases reported hearing decline. Sound/pressure induced vertigo and disequilibrium also demonstrated high rates of resolution. No complications were reported.

The minimally invasive middle fossa keyhole craniectomy is a novel approach for the repair of SSCD. This approach may contribute to resolved auditory and vestibular symptoms with low morbidity and quick recovery 4).

Reviews

A analysis included 24 studies that described 230 patients that underwent either an middle cranial fossa (MCF) (n = 148, 64%) approach or a transmastoid approach (TM) (n = 82, 36%) for primary surgical repair of SSCD. A greater percentage of patients in the MCF group experienced resolution of auditory symptoms (72% vs 59%, p = 0.012), aural fullness (83% vs 55%, p = 0.049), hearing loss (57% vs 31%, p = 0.026), and disequilibrium (75% vs 44%, p = 0.001) when compared to the TM group. The MCF approach was also associated with higher odds of symptom resolution for auditory symptoms (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.14-2.82), aural fullness (OR 4.02, 95% CI 1.04-15.53), hearing loss (OR 2.91, 95% CI 1.14-7.42), and disequilibrium (OR 3.94, 95% CI 1.78-8.73). The mean follow-up was 9 months.

The literature suggests that the MCF approach for the repair of SSCD is associated with greater symptom resolution when compared to the TM approach. This information could help facilitate patient discussions 5).

Case series

A total of 72 cases of SSCD in 60 patients were repaired via a middle fossa approach at a single institution. Main Outcome Measures  The distance from the proposed reference point to the dehiscence was statistically analyzed using Shapiro-Wilk’s goodness-of-fit test and Student’s t -test. Results  Average distance for all patients was 28.84 ± 2.22 mm (range: 22.96-33.43). Average distance for females was 29.08 mm (range: 24.56-33.43) versus 28.26 mm (range: 22.96-32.36) for males. There was no difference in distance by sex ( p  = 0.174). The distance measurements followed a normal distribution with 95% of the patients between 24.49 and 33.10 mm.

This study analyzed a potential reference point during a middle fossa approach for SSCD surgery. The distance from this reference point to the SSCD was found to be consistent and may serve as a readily identifiable landmark in localizing the dehiscence 6).

Case reports

A 35-year-old man with superior semicircular canal dehiscence treated by a joint neurosurgical and otolaryngological team 7).

1) , 3)

Mau C, Kamal N, Badeti S, Reddy R, Ying YM, Jyung RW, Liu JK. Superior semicircular canal dehiscence: Diagnosis and management. J Clin Neurosci. 2018 Feb;48:58-65. doi: 10.1016/j.jocn.2017.11.019. Epub 2017 Dec 7. Review. PubMed PMID: 29224712.
2)

Lagman C, Beckett JS, Chung LK, Chen CHJ, Voth BL, Gaonkar B, Gopen Q, Yang I. Novel Method of Measuring Canal Dehiscence and Evaluation of its Potential as a Predictor of Symptom Outcomes After Middle Fossa Craniotomy. Neurosurgery. 2017 Aug 9. doi: 10.1093/neuros/nyx430. [Epub ahead of print] PubMed PMID: 28945893.
4)

Vanessa T, Pelargos PE, Spasic M, Chung LK, Voth B, Ung N, Gopen Q, Yang I. Minimally Invasive Middle Fossa Keyhole Craniectomy for Repair of Superior Semicircular Canal Dehiscence. Oper Neurosurg (Hagerstown). 2017 Jun 1;13(3):317-323. doi: 10.1093/ons/opw046. PubMed PMID: 28521355.
5)

Nguyen T, Lagman C, Sheppard JP, Romiyo P, Duong C, Prashant GN, Gopen Q, Yang I. Middle cranial fossa approach for the repair of superior semicircular canal dehiscence is associated with greater symptom resolution compared to transmastoid approach. Acta Neurochir (Wien). 2017 Oct 11. doi: 10.1007/s00701-017-3346-2. [Epub ahead of print] Review. PubMed PMID: 29022108.
6)

Beckett JS, Chung LK, Lagman C, Voth BL, Jacky Chen CH, Gaonkar B, Gopen Q, Yang I. A Method of Locating the Dehiscence during Middle Fossa Approach for Superior Semicircular Canal Dehiscence Surgery. J Neurol Surg B Skull Base. 2017 Aug;78(4):353-358. doi: 10.1055/s-0037-1601886. Epub 2017 Apr 18. PubMed PMID: 28725523; PubMed Central PMCID: PMC5515662.
7)

Martin JE, Neal CJ, Monacci WT, Eisenman DJ. Superior semicircular canal dehiscence: a new indication for middle fossa craniotomy. Case report. J Neurosurg. 2004 Jan;100(1):125-7. PubMed PMID: 14743924.

Update: Geniculate neuralgia treatment

Geniculate neuralgia treatment

The treatment for geniculate neuralgia has not been established, although it seems reasonable that the therapeutic approaches used in other more common craniofacial neuralgias, such as trigeminal neuralgia, should be effective.

Conservative medical treatment is always the first-line therapy.

Mild cases may respond to carbamazepine sometimes in combination with phenytoin.

May responde to valproic acid.

Topical antibiotics for secondary infections of herpetic lesions.

Local anesthetic to external auditory canal.

Surgery

Surgical treatment should be offered if medical treatment fails. The two commonest surgical options are transection of the nervus intermedius, and microvascular decompression of the nerve at the nerve root entry zone of the brainstem. However, extracranial intratemporal division of the cutaneous branches of the facial nerve may offer a safer and similarly effective treatment.

The response to medical treatment for this condition varies between individuals. The long-term outcomes of surgery remain unknown because of limited data 1).

Rupa et al., postulate that geniculate ganglionectomy may be ineffective as the sole treatment for certain cases of geniculate neuralgia, and that nervus intermedius section may also be required to achieve a more complete deafferentation 2).

Excision of the nervus intermedius and/or of the geniculate ganglion by the middle cranial fossa approach without the production of facial paralysis, sometimes in combination with selective section of the Vth cranial nerve, has been successful in relieving the pain of geniculate neuralgia.

Microvascular decompression

Microvascular decompression may be effective as a treatment. Along its cisternal course, the nerve may be difficult to distinguish from the facial nerve. Based on case reports and small series, long-term pain control can be seen after nerve sectioning or microvascular decompression, but no prospective studies exist. Such studies are now necessary to shed light on the efficacy of surgical treatment of nervus intermedius neuralgia 3).

Complications

High-frequency hearing loss occurred after MVD for TGN, GPN, or GN, and the greatest incidence occurred on the ipsilateral side. This hearing loss may be a result of drill-induced noise and/or transient loss of cerebrospinal fluid during the course of the procedure. Changes in intraoperative BAEP waveforms were not useful in predicting HFHL after MVD. Repeated postoperative audiological examinations may be useful in assessing the prognosis of HFHL 4).

Case series

2002

Surgically excision of the nervus intermedius and geniculate ganglion via the middle cranial fossa approach, Review the long-term outcomes in 64 patients who were treated in this manner. Findings indicate that excision of the nervus intermedius and geniculate ganglion can be routinely performed without causing facial paralysis and that it is an effective definitive treatment for intractable geniculate neuralgia 5).

1991

A total of 31 surgical procedures were performed. Seventeen patients had sequential rhizotomies and one patient had microvascular decompression alone. Based on the clinical diagnosis, the nerves sectioned were singly or in combination: the nervus intermedius (14 patients), geniculate ganglion (10 patients), ninth nerve (14 patients), 10th nerve (11 patients), tympanic nerve (four patients), and chorda tympani nerve (one patient). Microvascular decompression of the involved nerves was undertaken in nine patients, in whom vascular loops were discovered. Adhesions (six patients), thickened arachnoid (three patients), and benign osteoma (one patient) were other intraoperative abnormalities noted. The overall success of these procedures in providing pain relief was 72.2%, and the mean follow-up period was 3.3 years (range 1 month to 14.5 years). There was no surgical mortality. Expected side effects were: decreased lacrimation, salivation, and taste related to nervus intermedius nerve section, and transient hoarseness and diminished gag related to ninth and 10th nerve section. Four patients developed sequelae consisting of sensorineural hearing loss, vertigo, and transient facial nerve paresis. One patient had a cerebrospinal fluid leak and another developed aseptic meningitis as postoperative complications. Except when primary glossopharyngeal neuralgia is the working diagnosis, a combined posterior cranial fossa-middle cranial fossa approach is recommended for adequate exploration and/or section of the fifth, ninth, and 10th cranial nerves as well as the geniculate ganglion and nervus intermedius 6).

1976

Excision of the nervus intermedius and/or of the geniculate ganglion by the middle cranial fossa approach without the production of facial paralysis, in any of 15 cases with geniculate neuralgia is reported. Use of these new techniques, sometimes in combination with selective section of the Vth cranial nerve, has been successful in relieving the pain of geniculate neuralgia 7).

Case reports

A 39-year-old man presented with a history of left “deep” ear pain within his ear canal. He noted occasional pain on the left side of his face around the ear. He had been treated with neuropathic pain medications without relief. His wife described suicidal ideations discussed by her husband because of the intense pain.

The patient’s neurologic examination was normal, and otolaryngologic consultation revealed no underlying structural disorder. Anatomic imaging revealed a tortuous vertebral artery-posterior inferior cerebellar artery complex with the posterior inferior cerebellar artery loop impinging on the root entry zone of the nervus intermedius-vestibulocochlear nerve complex and just inferior to the root entry zone of the facial nerve and a small anterior inferior cerebellar artery loop interposed between the cranial nerve VII-VIII complex and the hypoglossal and glossopharyngeal nerves. A left-sided retromastoid craniotomy was performed, and the nervus intermedius was transected. An arterial loop in contact with the lower cranial nerves at the level of the brainstem was mobilized with a polytetrafluoroethylene implant.

The patient indicated complete relief of his preoperative pain after surgery. He has remained pain-free with intact hearing and balance 8).

1)

Tang IP, Freeman SR, Kontorinis G, Tang MY, Rutherford SA, King AT, Lloyd SK. Geniculate neuralgia: a systematic review. J Laryngol Otol. 2014 May;128(5):394-9. doi: 10.1017/S0022215114000802. Review. PubMed PMID: 24819337.
2)

Rupa V, Weider DJ, Glasner S, Saunders RL. Geniculate ganglion: anatomic study with surgical implications. Am J Otol. 1992 Sep;13(5):470-3. PubMed PMID: 1443083.
3)

Tubbs RS, Steck DT, Mortazavi MM, Cohen-Gadol AA. The nervus intermedius: a review of its anatomy, function, pathology, and role in neurosurgery. World Neurosurg. 2013 May-Jun;79(5-6):763-7. doi: 10.1016/j.wneu.2012.03.023. Epub 2012 Apr 3. Review. PubMed PMID: 22484073.
4)

Thirumala P, Meigh K, Dasyam N, Shankar P, Sarma KR, Sarma DR, Habeych M, Crammond D, Balzer J. The incidence of high-frequency hearing loss after microvascular decompression for trigeminal neuralgia, glossopharyngeal neuralgia, or geniculate neuralgia. J Neurosurg. 2015 Dec;123(6):1500-6. doi: 10.3171/2014.10.JNS141101. Epub 2015 May 1. PubMed PMID: 25932612.
5)

Pulec JL. Geniculate neuralgia: long-term results of surgical treatment. Ear Nose Throat J. 2002 Jan;81(1):30-3. Review. PubMed PMID: 11816385.
6)

Rupa V, Saunders RL, Weider DJ. Geniculate neuralgia: the surgical management of primary otalgia. J Neurosurg. 1991 Oct;75(4):505-11. PubMed PMID: 1885967.
7)

Pulec JL. Geniculate neuralgia: diagnosis and surgical management. Laryngoscope. 1976 Jul;86(7):955-64. PubMed PMID: 933690.
8)

Tubbs RS, Mosier KM, Cohen-Gadol AA. Geniculate neuralgia: clinical, radiologic, and intraoperative correlates. World Neurosurg. 2013 Dec;80(6):e353-7. doi: 10.1016/j.wneu.2012.11.053. Epub 2012 Nov 23. PubMed PMID: 23178920.

Update: Giant GH secreting pituitary adenoma

Giant GH secreting pituitary adenoma

Patients with acromegaly usually harbor pituitary macroadenomas measuring between 10 and 30 mm in maximal diameter. Giant (adenoma size ≥40 mm) GH secreting pituitary adenoma are rarely encountered.

They are invasive, uncontrolled by surgery, and respond poorly to medical treatment. Aggressive multimodal therapy is critical for their management, enhancing control rate and biochemical remission 1).

Case series

2017

Giordano et al., present the clinical, radiological and hormonal status of three patients affected by invasive GH-secreting pituitary adenomas without clinical signs and symptoms of acromegaly with elevation of serum IGF-1 from a series of 142 pituitary adenomas operated in the Department of Neurosurgery, International Neuroscience Institute-Hannover, Germany with the aid of intraoperative magnetic resonance imaging(MRI). Total tumor removal was possible in two of the three cases; the patients show normal hormonal status and no recurrence at long-term follow-up. In the third case, due to the different features of the tumor, complete resection was not possible and a multimodal treatment was performed that allowed regularization of the hormonal status and control of the residual tumor. GH-secreting adenomas without clinical manifestation of acromegaly are uncommon lesions. Total microsurgical excision can be curative. However, in case of partial removal, a tailored adjuvant treatment should be considered to preserve the quality of life of the patient and avoid regrowth of the lesion. In not resectable tumors, preoperative medical treatment with somatostatin analogues is always an option 2).

2015

Shimon et al. identified 34 patients (15 men and 19 females) with giant adenomas among 762 subjects (4.5%) with acromegaly, and characterized their clinical characteristics and response to treatment.

Mean age at diagnosis was 34.9±12.5 years (range, 16-67 years). Mean adenoma size was 49.4±9.4 mm (range, 40-80 mm); 30 adenomas showed cavernous sinus invasion and 32 had suprasellar extension. Twenty-nine (85%) patients had visual field defects. Mean baseline IGF1 was 3.4±1.8×ULN. All patients except one underwent pituitary surgery (one to three procedures), but none achieved hormonal remission following first surgery. Among the 28 subjects with visual disturbances, 14 recovered post-operatively and 13 improved. Treatment with somatostatin analogs was given to all patients after surgical failure. Six achieved remission, nine others were partially controlled (IGF1<1.5×ULN; 3/9 when combined with cabergoline), and 17 did not respond (two were lost). Nine patients were treated with pegvisomant, alone (n=4) or in combination with somatostatin analogs (n=5); five are in remission and two are partially controlled. Pasireotide-LAR achieved hormonal remission in one of the six patients. Currently, after a mean follow-up period of 8.9 years, 17 patients are in biochemical remission, eight are partially controlled, and seven are uncontrolled (two were lost to follow-up).

Giant GH-secreting adenomas are invasive, uncontrolled by surgery, and respond poorly to medical treatment. Aggressive multimodal therapy is critical for their management, enhancing control rate and biochemical remission 3).

Case reports

A 23-year-old male patient presented with continuous increase in height during the past 6 years due to a GH-secreting giant pituitary adenoma. Because of major intracranial extension and failure of octreotide treatment to shrink the tumour, the tumour was partially resected by a trans-frontal surgical approach. At immunohistochemistry, the tumour showed a marked expression of GH and a sparsely focal expression of prolactin. Somatostatin receptors (sst) 1-5 were not detected. Tumour tissue weakly expressed dopamine receptor type 2. The Gs alpha subunit was intact. Conversion from somatostatin analogue to pegvisomant normalized insulin-like-growth-factor-I (IGF-I) levels and markedly improved glucose tolerance.

Pegvisomant is a potent treatment option in patients with pituitary gigantism. In patients who do not respond to somatostatin analogues, knowledge of the SST receptor status may shorten the time to initiation of pegvisomant treatment 4).

1)

Shimon I, Jallad RS, Fleseriu M, Yedinak CG, Greenman Y, Bronstein MD. Giant GH-secreting pituitary adenomas: management of rare and aggressive pituitary tumors. Eur J Endocrinol. 2015 Jun;172(6):707-13. doi: 10.1530/EJE-14-1117. Epub 2015 Mar 19. PubMed PMID: 25792375.
2)

Giordano M, Samii A, Fahlbusch R. Aggressive somatotrophinomas lacking clinical symptoms: neurosurgical management. Neurosurg Rev. 2017 Dec 30. doi: 10.1007/s10143-017-0940-y. [Epub ahead of print] PubMed PMID: 29290044.
3)

Shimon I, Jallad RS, Fleseriu M, Yedinak CG, Greenman Y, Bronstein MD. Giant GH-secreting pituitary adenomas: management of rare and aggressive pituitary tumors. Eur J Endocrinol. 2015 Jun;172(6):707-13. doi: 10.1530/EJE-14-1117. Epub 2015 Mar 19. PubMed PMID: 25792375.
4)

Müssig K, Gallwitz B, Honegger J, Strasburger CJ, Bidlingmaier M, Machicao F, Bornemann A, Ranke MB, Häring HU, Petersenn S. Pegvisomant treatment in gigantism caused by a growth hormone-secreting giant pituitary adenoma. Exp Clin Endocrinol Diabetes. 2007 Mar;115(3):198-202. PubMed PMID: 17427111.

Update: Computed Tomography for chronic subdural hematoma

Computed Tomography for chronic subdural hematoma

The routine use of Head computed tomography in most emergency facilities has made the diagnosis of a chronic subdural hematoma commonplace 1).

Density of the chronic subdural hematoma (cSDH) is variable. It often appears to be mixed density. Multiple densities of cSDH may result from multiple episodes of trauma, usually in the aged. It is hard to remember all the trivial traumas for the patients with the mixed density cSDHs.

CT-scan is able to provide the diagnosis of chronic subdural hematoma in more than 90% of the cases. It usually shows a peri-cerebral fluid collection along the convexity, with a convex outer border, and an irregular concave inner border. The density of the collection depends on the age of the intracranial hematoma. The main difficulties, in term of diagnosis, result from bilateral isodense chronic subdural hematoma, and differential diagnosis between hematoma, subdural hygroma, and subdural empyema. Some rare localisations can sometimes be seen (posterior fossa, skull base…). A double density with a sedimentation level, or heterogeneity of the hematoma, can sometimes be seen too 2).

Classification

The cSDHs can be classified into four groups; hypodensity, homogeneous isodensity, layered type, and mixed type on the basis of CT scans 3).

Routine Brain Computed Tomography after Evacuation

Routine post-operative CT brain for burr hole drainage of CSDH may be unnecessary in view of the good predictive value of pre-operative volume, and also because it is not predictive of the clinical outcome 4).

A study of Ng et al. compared pre-operative and early post-operative CT findings to determine the factors affecting residual hematoma and evaluate if early post-operative CT scans are useful in the management of CSDH.

Forty-three patients who underwent burr hole drainage of unilateral CSDH from August 2006 to January 2013 and had routine post-operative CT scans within 48 hours of surgery were selected. Data regarding age, sex, neurological deficit, Glasgow Coma Scale (GCS), pre-existing medical conditions, use of antiplatelets or anticoagulation, operative time, usage of drains, and number of burr holes were obtained. The pre-operative CSDH volume, CSDH density, and midline shift were measured. Residual volume was calculated from early post-operative CT scans. Clinical outcome was evaluated with Glasgow Outcome Scale (GOS) at the time of discharge. Statistical analysis was performed to look for correlation between the pre-operative factors and residual volume, and the residual volume and GOS.

Pre-operative volume was found to correlate significantly with post-operative residual volume. There was no significant correlation between all other pre-operative factors and residual volume. There was also no correlation between residual volume and GOS at discharge 5).


Routinely postoperative control brain CT scan 4 to 6 weeks after the evacuation of a CSDH has no clinical value 6).

In a retrospective study Pedersen et al. examined 202 patients who during a 2-year period from 2011 and 2012 underwent surgical treatment for chronic subdural hematoma (CSDH). Information on patient age, sex, alcohol consumption, anticoagulant/antiplatelet treatment, history of head trauma, Glasgow coma scale (GCS), neurological symptoms, laterality of CSDH, and surgical technique was retrieved from patient charts.

Overall, 27 out of 202 patients had a recurrence of CSDH and re-evacuation of the hematoma was performed. In all patients recurrence of neurological symptoms preceded the planned postoperative control brain CT 4 to 6 weeks after primary surgery.

Routinely postoperative control brain CT scan 4 to 6 weeks after the evacuation of a CSDH has no clinical value 7).

1)

Chen JC, Levy ML. Causes, epidemiology, and risk factors of chronic subdural hematoma. Neurosurg Clin N Am. 2000 Jul;11(3):399-406. Review. PubMed PMID: 10918008.
2)

Guénot M. [Chronic subdural hematoma: diagnostic imaging studies]. Neurochirurgie. 2001 Nov;47(5):473-8. French. PubMed PMID: 11915760.
3)

Park HR, Lee KS, Shim JJ, Yoon SM, Bae HG, Doh JW. Multiple Densities of the Chronic Subdural Hematoma in CT Scans. J Korean Neurosurg Soc. 2013 Jul;54(1):38-41. doi: 10.3340/jkns.2013.54.1.38. Epub 2013 Jul 31. PubMed PMID: 24044079; PubMed Central PMCID: PMC3772285.
4) , 5)

Ng HY, Ng WH, King NK. Value of routine early post-operative computed tomography in determining short-term functional outcome after drainage of chronic subdural hematoma: An evaluation of residual volume. Surg Neurol Int. 2014 Sep 19;5:136. doi: 10.4103/2152-7806.141299. eCollection 2014. PubMed PMID: 25298918; PubMed Central PMCID: PMC4174672.
6) , 7)

Pedersen CB, Sundbye F, Poulsen FR. No Value of Routine Brain Computed Tomography 6 Weeks after Evacuation of Chronic Subdural Hematoma. Surg J (N Y). 2017 Nov 27;3(4):e174-e176. doi: 10.1055/s-0037-1607215. eCollection 2017 Oct. PubMed PMID: 29184916; PubMed Central PMCID: PMC5703687.

Update: Abciximab

Abciximab

Abciximab is made from the Fab fragments of an immunoglobulin that targets the glycoprotein IIbIIIa receptor on the platelet membrane.

Abciximab (previously known as c7E3 Fab), a glycoprotein IIb/IIIa receptor antagonist manufactured by Janssen Biologics BV and distributed by Eli Lilly under the trade name ReoPro, is a platelet aggregation inhibitor mainly used during and after coronary artery procedures like angioplasty to prevent platelets from sticking together and causing thrombus (blood clot) formation within the coronary artery. It is a glycoprotein IIb/IIIa inhibitor.

While abciximab has a short plasma half-life, due to its strong affinity for its receptor on the platelets, it may occupy some receptors for weeks. In practice, platelet aggregation gradually returns to normal about 96 to 120 hours after discontinuation of the drug 1).

Rx: 0.25 mg/kg IV bolus over at least 1 min, 10-60 min before start of PCI, THEN

0.125 mcg/kg/min IV continuous infusion for 12 hr; not to exceed infusion rate of 10 mcg/min


Patel et al. evaluated the efficacy of treatment of acute thrombus formation with abciximab, as well as the results of pre-procedure platelet inhibition testing.

Acute thrombus formation was encountered in five patients following PED placement (5%). Early angiographic signs were present in all cases and included progressive stagnation of blood flow in covered side branches, occlusion of covered side branches, excessive stagnation of blood flow in the target aneurysm, as well as occlusion of the target aneurysm. These sequelae completely resolved following abciximab treatment in all five cases, with no permanent neurological morbidity or mortality. Four of the five patients had a pre-procedure P2Y12 value >200 (range 201-227).

Progressive stagnation or occlusion of covered side branches or target aneurysm are early angiographic signs of acute thrombus formation following PED placement and should prompt immediate treatment with a glycoprotein IIb/IIIa inhibitor. Platelet inhibition testing may help identify those patients who are at an increased risk for this complication 2).


A review provides a comprehensive evaluation of the current published literature pertaining to the use of all available GP IIb/IIIa inhibitors for thromboembolic complications, providing recommendations for dosing and administration of abciximab, eptifibatide, and tirofiban based on previously published rates of efficacy and intracranial hemorrhage 3).


Abciximab produces a high rate of angiographic improvement and a low incidence of postprocedural infarct in neuroendovascular procedures complicated by thromboemboli. IA abciximab produces greater angiographic improvement than IV treatment. Postprocedural infarction is less common in patients with complete angiographic response than in those with partial or no response 4).


In acute ICA-MCA/distal ICA occlusions, extracranial stenting followed by intracranial IA Abciximab and thrombectomy appears feasible, effective, and safe. Further evaluation of this treatment strategy is warranted 5).


There was no statistically significant difference in the rate of ischemic stroke or postprocedural hemorrhage with the use of abciximab compared with the use of eptifibatide in treatment of intraprocedural thrombosis 6).

1)

Tanguay, J.F., Eur Heart J 1999; 1 (suppl E): E27-E35
2)

Patel A, Miller TR, Shivashankar R, Jindal G, Gandhi D. Early angiographic signs of acute thrombus formation following cerebral aneurysm treatment with the Pipeline embolization device. J Neurointerv Surg. 2017 Nov;9(11):1125-1130. doi: 10.1136/neurintsurg-2016-012701. Epub 2016 Oct 21. PubMed PMID: 27770038.
3)

Dornbos D 3rd, Katz JS, Youssef P, Powers CJ, Nimjee SM. Glycoprotein IIb/IIIa Inhibitors in Prevention and Rescue Treatment of Thromboembolic Complications During Endovascular Embolization of Intracranial Aneurysms. Neurosurgery. 2017 May 3. doi: 10.1093/neuros/nyx170. [Epub ahead of print] PubMed PMID: 28472526.
4)

Kansagra AP, McEachern JD, Madaelil TP, Wallace AN, Cross DT 3rd, Moran CJ, Derdeyn CP. Intra-arterial versus intravenous abciximab therapy for thromboembolic complications of neuroendovascular procedures: case review and meta-analysis. J Neurointerv Surg. 2017 Feb;9(2):131-136. doi: 10.1136/neurintsurg-2016-012587. Epub 2016 Aug 18. PubMed PMID: 27540089.
5)

Al-Mufti F, Amuluru K, Manning NW, Khan I, Peeling L, Gandhi CD, Prestigiacomo CJ, Pushchinska G, Fiorella D, Woo HH. Emergent carotid stenting and intra-arterial abciximab in acute ischemic stroke due to tandem occlusion. Br J Neurosurg. 2017 Oct;31(5):573-579. doi: 10.1080/02688697.2017.1297377. Epub 2017 Mar 15. PubMed PMID: 28298139.
6)

Adeeb N, Griessenauer CJ, Moore JM, Foreman PM, Shallwani H, Motiei-Langroudi R, Gupta R, Baccin CE, Alturki A, Harrigan MR, Siddiqui AH, Levy EI, Ogilvy CS, Thomas AJ. Ischemic Stroke After Treatment of Intraprocedural Thrombosis During Stent-Assisted Coiling and Flow Diversion. Stroke. 2017 Apr;48(4):1098-1100. doi: 10.1161/STROKEAHA.116.016521. Epub 2017 Feb 28. PubMed PMID: 28246277.

Update: Ependymoma RELA fusion positive

Ependymoma RELA fusion positive

Ependymoma RELA fusion-positive is a accepted variant of ependymoma, only recognised in the World Health Organization Classification of Tumors of the Central Nervous System 2016 1).

Epidemiology

They are the most common type of supratentorial ependymoma in children, and not found in the posterior fossa or spinal cord.

Two-thirds of supratentorial (ST) ependymomas harbor oncogenic fusions of RELA.

Outcome

The protein product is the principal effector of canonical Nuclear factor kappa signaling. RELA fusion proteins activate signaling for tumor proliferation and malignant progression, resulting in poorer prognoses in these patients compared to those in patients with other ST ependymomas.

In a study, Nakamura et al. encountered a case of C11orf-RelA fusion-positive ST anaplastic ependymoma that was diagnosed in first tumor resection surgery of multi-staged gross total resection with molecular evidence. In ependymomas, regardless of tumor location or pathological grade, subtotal resection is associated with higher rates of mortality compared with GTR 2).

In posterior fossa ependymoma group A (PF-EPN-A) tumors, telomerase activity varied and was significantly associated with dismal overall survival, whereas telomerase reactivation was present in all supratentorial RelA fusion-positive (ST-EPN-RELA) ependymomas 3).

Pathology

These tumours can be both grade II or III and demonstrate a variety of histological morphologies, although clear cells and prominent vascularity are common.

The presence of the RELA fusion gene can be assessed with FISH.

Immunophenotype

GFAP positive

EMA positive

L1CAM positive correlates closely with the presence of RELA fusion not exclusive to ependymomas.

Treatment

Actinomycin D could constitute a promising therapeutic option for Ependymoma RELA fusion positive, whose tumours frequently exhibit p53 inactivation 4).

Case reports

2017

A case of aggressive anaplastic ependymoma arising in the right frontoparietal lobe, which had genetically 1q25 gain, CDKN2A homozygous deletion, and L1CAM overexpression. The patient was a 10-year-old boy who underwent four times of tumor removal and seven times of gamma knife surgery. Metastatic loci were scalp and temporalis muscle overlying primary operation site, lung, liver, buttock, bone, and mediastinal lymph nodes. He had the malignancy for 10 years and died. This tumor is a representative case of Ependymoma RELA fusion positive, showing aggressive behavior 5).

1)

Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D, Cavenee WK, Ohgaki H, Wiestler OD, Kleihues P, Ellison DW. The 2016 World Health Organization Classification of Tumors of the Central Nervous System: a summary. Acta Neuropathol. 2016 Jun;131(6):803-20. doi: 10.1007/s00401-016-1545-1. Epub 2016 May 9. Review. PubMed PMID: 27157931.

2)

Nakamura T, Fukuoka K, Ikeda J, Yoshitomi M, Udaka N, Tanoshima R, Tateishi K, Yamanaka S, Ichimura K, Yamamoto T. Encouraging option of multi-staged gross total resection for a C11orf-RelA fusion-positive supratentorial anaplastic ependymoma. Brain Tumor Pathol. 2017 Oct;34(4):160-164. doi: 10.1007/s10014-017-0297-5. Epub 2017 Aug 22. PubMed PMID: 28831588.

3)

Gojo J, Lötsch D, Spiegl-Kreinecker S, Pajtler KW, Neumayer K, Korbel P, Araki A, Brandstetter A, Mohr T, Hovestadt V, Chavez L, Kirchhofer D, Ricken G, Stefanits H, Korshunov A, Pfister SM, Dieckmann K, Azizi AA, Czech T, Filipits M, Kool M, Peyrl A, Slavc I, Berger W, Haberler C. Telomerase activation in posterior fossa group A ependymomas is associated with dismal prognosis and chromosome 1q gain. Neuro Oncol. 2017 Sep 1;19(9):1183-1194. doi: 10.1093/neuonc/nox027. PubMed PMID: 28371821; PubMed Central PMCID: PMC5570194.

4)

Tzaridis T, Milde T, Pajtler KW, Bender S, Jones DT, Müller S, Wittmann A, Schlotter M, Kulozik AE, Lichter P, Peter Collins V, Witt O, Kool M, Korshunov A, Pfister SM, Witt H. Low-dose Actinomycin-D treatment re-establishes the tumoursuppressive function of P53 in RELA-positive ependymoma. Oncotarget. 2016 Sep 20;7(38):61860-61873. doi: 10.18632/oncotarget.11452. PubMed PMID: 27556362; PubMed Central PMCID: PMC5308696.

5)

Kim SI, Lee Y, Kim SK, Kang HJ, Park SH. Aggressive Supratentorial Ependymoma, RELA Fusion-Positive with Extracranial Metastasis: A Case Report. J Pathol Transl Med. 2017 Nov;51(6):588-593. doi: 10.4132/jptm.2017.08.10. Epub 2017 Nov 15. PubMed PMID: 29161788.