Intradural Component Research Articles

C2 Nerve Sheath Tumors: An Analysis of Radiological – Intraoperative Concordance for Intradural Extension and Systematic Review

Background: Nerve sheath tumors (NSTs) of C2 nerve-root are clinically and radiologically distinct from NSTs of rest of the spine. On imaging, they appear to have a major intradural component in addition to the large extradural part. Thus, they may require durotomy with its possible added complications. Objective: The aim of this study is to evaluate the radiological – intra-operative discordance for intradural component and need for tailored durotomy for complete resection of C2 NSTs. Material and Methods: We retrospectively analyzed 14 consecutively operated patients of C2 NSTs over the past 10 years (2013-2023). Dura was opened in patients where there was a radiological or intra-operative suspicion of intradural extension. Results: Mean(±SD) age at presentation was 37.5(±13) years, with no gender predominance (Male:Female-1.3:1). Dura was opened in 7(50%) patients. On preoperative radiological study, all the patients had a dominant extradural tumor, while 7(50%) patients appeared to have an intradural tumor extension also. Intra-operatively, 5(35.7%) of these 7 patients had only extradural component, while 2(14.3%) patients had an intradural extension. 7(50%) patients had extradural tumor radiologically, while only one patient was found to have a small intradural extension intraoperatively. Thus, only 21.4% of the patients (n=3) were found to have an intradural extension as against 50%(n=7) predicted on imaging. Post-operatively there was clinical improvement in all 14 patients (100%). Conclusions: Due to radiological and intra-operative discordance in intradural tumor extension, decision for midline durotomy should be taken following excision of extradural component. Thus, limiting the number of unnecessary midline-durotomies.

Giant Invasive Schwannomas of C1 Root – Technical Challenges and Report of the First Two Cases in Literature

Abstract Giant invasive schwannomas (GISs) have been defined as different from other spinal schwannomas. C1 schwannomas are rare and often described with other high cervical tumors. GISs of C1 have not been previously described. Two cases of GIS are reported. In both patients, presenting with myelopathy, the lesions were extradural and intradural with posterior, lateral, and anterior extensions, compressing the cervicomedullary junction (CMJ) and displacing it. The V3-4 segments of the vertebral artery (VA) were closely associated. A posterolateral approach was used to initially expose and debulk the extradural portion of the lesion, which allowed access to the intradural component. The latter was followed anterior and/or posterior to the CMJ and excised completely. The tumors were dissected at the VA. Bleeding from the perivertebral venous plexus was controlled using topical hemostats. A small bit of tumor was left in a blind area anterior to the C1 arch in one patient. There were no complications and both patients improved in the postoperative period. GIS of the C1 are rare lesions in a difficult location. Complex relationships to the CMJ, lower cranial nerves, VA, and bony spine need a careful preoperative understanding of the anatomy and planning of surgery.

Cystic Posterior Neck Mass in a Premature Newborn

Congenital dermal sinus is a type of occult spinal dysraphism. It is a result of incomplete separation of the cutaneous ectoderm from neural ectoderm. MRI can aid in identifying the subtype of spinal dysraphism however, surgery is always recommended to dissect the intradural component.

Operative Technique for Resection of a Ventral Transdural Retro-Odontoid Pannus: A 2-Dimensional Operative Video

Retro-odontoid pseudotumors are rare inflammatory complications of atlantoaxial instability often associated with cervical degenerative disease and rheumatoid arthritis. While propagation of these lesions has been shown to cause spinal cord compression and cervical myelopathy, intradural extension has rarely been reported. In this manuscript and 2-dimensional illustrative intraoperative video, we demonstrate cervical decompression, removal of the intradural component, and stabilization with C1-2 instrumentation using a posterior approach. A 71-year-old patient presented with progressive cervical myelopathy. Preoperative imaging demonstrated a large retro-odontoid pannus causing severe spinal cord compression and an associated contrast-enhancing intradural lesion, in the absence of obvious C1-2 instability or fractures on computed tomography scan. C1-2 posterior decompression and fusion were performed with maximally safe intradural pannus resection and ventral dural reconstruction. Postoperatively, the patient experienced significant improvement in myelopathic symptoms. Imaging demonstrated good spinal cord decompression with complete intradural pannus resection and debulking of the extradural component. Our outcome in this rare complication suggests a posterior approach may be effective in treating similar patients.

Pipeline flow diversion with adjunctive coil embolization for internal carotid artery aneurysms following an intradural component: results in 46 consecutive aneurysms from a Japanese single-center experience.

In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6mm; median neck width, 6.3mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small (< 10mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10mm) aneurysms (P = .024). The median clinical follow-up was 22months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively.

Operative nuances and surgical limits of the endoscopic approach to clival chordomas and chondrosarcomas: A single-center experience of 72 patients

ObjectiveGross total resection (GTR) is the mainstay therapy for chordomas and chondrosarcomas to have the best prognosis. The aims of this study were to specify the limits of EEA, emphasize the need for additional combined approaches for tumors beyond these limitations for high resection rates, discuss the prognostic factors and operative nuances that affect GTR, and present the causes and characteristics of early and late recurrences. MethodsWe retrospectively analyzed the endoscopic endonasal surgeries in the Pituitary Research Center and Neurosurgery Department of the Kocaeli University Faculty of Medicine, Turkey between January 2004 and December 2019. We retrospectively reviewed the medical data, radiological images, and surgical videos of patients, and 72 patients with chordoma and chondrosarcoma were included in the study. ResultsBased on pathology reports, 72 patients (seven pediatric) were identified, to whom 91 endoscopic operations were performed. We determined the surgical limitations for each clival segment as superior, middle, and inferior. Then, we divided these into three subgroups according to whether the tumor shows dural invasion (extradural chordoma, large extradural - minimal intradural component, and minimal extradural - large intradural component). The tumors of 19 (26.4%), 25 (26.4%), and nine (12.5%) patients originated from the superior, middle, and inferior clivus, respectively. Nineteen (26.4%) patients had panclival involvement. GTR was performed in 47 (65.3%) the patients. The GTR rate in patients with panclival tumors was 47.3% (9/19). The experience, lateralization, dural involvement, and origin of the clivus affecting GTR were analyzed. Extradural – intradural extensions were verified as negative predictor factors for GTR, whereas tumors located in the superior (OR: 16.710, p=0.030) and middle (OR: 11.154, p=0.023) segments were positive predictive factors for GTR. ConclusionAn increasing experience in endoscopic surgery significantly increases the GTR rates by widening the surgical limitations. Due to dense bone infiltration and adhesion to critical neurovascular structures, recurrence rates are high despite performing GTR. Although surgery and adjuvant treatments improve the 5-year survival of patients, the mortality rates remain high. Therefore, surgery of these tumors should be performed by experienced centers. In addition to surgical and adjuvant therapies, targeted molecular and translational biological therapies are also needed for chordomas and chondrosarcomas in the future.

Basilar Artery Injury During Endonasal Surgery: Stepwise to Control Bleeding.

Intraoperative injury during endoscopic endonasal surgery of the carotid artery has been previously described in the literature. However, the accidental damage of the basilar artery in such scenario is not defined. To define the protocol of action for massive bleeding from an artery in the posterior fossa. The reported patient was diagnosed with a partially calcified clival chordoma featured by a huge intradural component. An endoscopic endonasal transpterygoid transclival approach was selected for the treatment of this tumor. During the surgical procedure, the basilar artery injury was injured, causing intense bleeding. We present and discuss the surgical maneuvers that could save a patient's life after this dramatic complication. Different techniques were performed in order to control the massive bleeding, including injection of hemotastic matrix with thrombin (Floseal©), bipolar coagulation, and vessel reconstruction by means of a vascular clip. Finally, an autologous muscle graft reinforced with an overlying fibrin sealant patch (Tachosil©) was chosen and was an effective technique. Afterwards, the patient was treated with a flow diverter device to occlude an iatrogenic pseudoaneurysm. A monoplegia of the right upper limb was the only remarkable sequel 6 mo after surgery. The muscle graft together with the coordinated action with interventional neuroradiology for the reconstruction of the vessel are possibly the best options to try to preserve the neurological function. In such a scenario, the assumption of potential ischemic events prevails over the intraoperative death of the patient.

Posterior Midline Approach for a C2 Schwannoma: 2-Dimensional Operative Video.

C2 schwannomas are rare lesions that may develop in the spinal canal, in the area of the C2 ganglion situated posterior to the C1C2 articulation, in the extraspinal area or in a combination of these 3 sectors.1,2 The surgical removal of these lesions is delicate because of the intimate relationships the schwannomas develop with the V3 segment of the vertebral artery. A variety of lateral, far-lateral, or extreme lateral approaches have been described in order to tackle these lesions. We use a posterior midline approach that takes advantage of the predominantly extradural development of C2 schwannomas. In this technique, the main step is the debulking of the posterior articular sector of the tumor, which is easily accessible through a midline posterior approach and necessitates minimal bone removal. In most cases, removal of the homolateral posterior arch of C1 is sufficient in order to create an adequate access. These maneuvers create the necessary space for dissecting both the intradural and extraspinal sectors of the schwannoma. We present this technique through a case with a minimal intradural component exerting mainly a lateral compression of the spinal cord. The tumor was operated through the midline mini-invasive posterior approach with a favorable result. We demonstrate the surgical technique in video and discuss the nuances.

Management of a complex glomus jugulare tumor with severe brainstem compression.

Surgery of glomus jugulare tumors is complex, but when these tumors have a large intradural component and cause brainstem compression they became a challenge to the surgeon. It is crucial to preoperatively understand the anatomy of the tumor and analyze its relationship with the temporal bone, facial nerve, and foramen jugular neurovascular structures. We present a case of a male patient with a complex glomus jugulare tumor causing severe brainstem compression. Nuances of technique and surgical pearls related to the management of complex jugulare tumors are discussed and illustrated in this operative video.The video can be found here: https://youtu.be/oCjzp0kFRGc.

The Significance of Intraoperative Magnetic Resonance Imaging in Resection of Skull Base Chordomas

Skull base chordoma can be a challenging surgical entity because of its invasive nature. In this study, the role of intraoperative magnetic resonance imaging (iMRI) to optimize the resection of skull base chordomas is evaluated. We performed a retrospective analysis of operated patients with skull base chordomas in the setting of iMRI. The clinical records, operative notes, radiologic images, tumor volumetry, location of the residual tumor, and surgical outcome were evaluated. Fifteen patients were operated on for resection of skull base chordomas between 2010 and 2017 in our institution. Gross total resection was planned and achieved in 8 patients and partial resection in 7 patients. In 8 patients (53.3%), the preoperatively planned volume of resection was achieved and confirmed in the first iMRI control. In 7 patients, repeated iMRI controls were required to achieve the surgical target. In 3 patients, the tumor residual requiring further resection was located in the clivus and in 4 patients in the intradural space. The improvement of the preoperative deficits showed a significant statistical association with the resection of the intradural component and decompression of the brainstem. This study shows that iMRI is a safe method for intraoperative assessment of the degree of resection and the volume and location of residual tumor when resecting skull base chordomas. When gross total resection of the tumor is not feasible, iMRI can be a useful tool for targeted tumor resection.

P3.CR-34 A Giant Ganglioneuroma of the Thoracic Spine

1/Case History: A 9-year old girl presented to our Department for a chronic cough. Her medical history revealed that she had pneumonia at the age of 2 years. The family history was marked by an allergic rhinitis in the father. On examination, she was afebrile.Full clinical examination revealed decreased breath sound in the left lung. 2/Investigations: Laboratory investigations were normal. The Chest CT-scan revealed a well-circumscribed mediastinal mass measuring 8.6cm*7.8cm*6.8cm. It extended through the neural foramen of T9 and also in the left chest cavity behind the aortic cross and the esophagus. Magnetic Resonance imaging showed a long intra-dural extra-medullary tumor extending from T6 to T11 levels. It extended through the left T9 neural foramen into the left thoracic cavity. The intervertebral foramen was enlarged. The thoracic aorta was totally sheathed. The lesion was mildly hypo-intense on T1-weighted imaging and heterogeneously hypo-intense on T2-weighted imaging. This radiological aspect could suggest a ganglioneuroma or a shwannoma. 3/Treatment: The multidisciplinary team decision was to perform surgery. Final histology demonstrated a well-circumscribed ganglioneuroma with negative margins. The case was reviewed at the Oncology multidisciplinary team. The decision was made to proceed with active follow-up without any adjuvant therapy given that it’s benign. The patient is currently doing well 2 years from her initial diagnosis. 4/Discussion: Thoracic intradural extra medullary Ganglioneuromas are very rare benign tumors of the autonomic nerve fibers. Most of them are incidentally discovered. In this case, our patient had no significant clinical symptoms apart from a chronic cough. The thoracic location, the potential of growth the large-size of the tumor (extending to the left chest wall with an intra-dural component) and the radiological profile, makes it therefore rare and unusual. It also illustrates the complexities of the management of this rare tumor. In fact, surgical treatment is usually safe and efficient. But, it can be more complicated in case of a such large-sized mass. So, a 2-step surgical intervention should be performed. Ganglioneuroma has commonly a good prognosis given its low-risk of recurrence and low-metastatic potential. However, it can become cancerous and spread to other organs.

Spinal tumours: diagnosis, clinical presentation and principles of treatment

Spinal tumours can be categorized as primary or metastatic. Primary neoplasms of the spine are rare and constitute less than 5% of bony tumours accounting for 2.5–8.5 affected individuals per 100,000 people per year. Primary spinal tumours can be divided into benign and malignant. Metastatic disease of the spine is much more common with 40–80% of patients who die of cancer having bony metastases at the time of their death and the spine being one of the most common sites of metastasis. A further subdivision in both benign and malignant disease is anatomical – that of bony and intradural components, though the focus in the current review is on the bony involvement. A key presenting feature is pain, with characteristic features which will be discussed in detail. Meticulous clinical assessment and work-up with early recognition and diagnosis can significantly improve morbidity and be curative in benign disease. Despite advances in treatment, the overall prognosis in malignant spinal disease, either metastatic or primary is relatively poor. This chapter provides a broad overview of neoplastic conditions looking at presenting signs and symptoms, differentials, clinical assessment and principles of management. This should allow for prompt recognition and expedite treatment.

Extracranial growth of glioblastoma multiforme

We present a 59-year-old woman who noted an enlarging lump on her forehead 6months after a left frontotemporal craniotomy for tumor resection and chemoradiation of her primary glioblastoma multiforme (GBM). GBM is a highly aggressive intracranial neoplasm associated with the shortest survival time of any primary central nervous system malignancy. Extracranial metastasis is rare, especially without previous surgical disruption of the dura and calvarium, which has been postulated to cause seeding of the extracranial space with tumor cells. This patient’s MRI revealed tumor recurrence for which she underwent repeat resection. Histopathology confirmed GBM with unmethylated O-6-methylguanine-DNA methyltransferase and wildtype isocitrate dehydrogenase 1 status, as well as tumor invasion through the bone and subdermal space. The genetic and molecular factors that predict extracranial invasion remain unclear and require further investigation. Emerging data on circulating tumor cells in GBM patients indicate that extraaxial metastasis may be part of the disease course in some, particularly in long term survivors. Furthermore, the proximity of calvarial and scalp lesions to previous surgical sites and the time course in which they emerge after surgery suggests that iatrogenic seeding may also play a role in metastasis. With heightened awareness of the phenomenon, surgical strategies such as watertight approximation of the dura, bone flap replacement, or changing surgical instruments once the intradural component is complete may prove useful to prevent seeding. Prophylactic craniospinal irradiation may also be an appropriate tool in patients at high risk for metastasis, although this population is difficult to identify.

Transforaminal Retrojugular Approach (TFRA) for Resection of Dumbbell Nerve Sheath Tumors in the Cervical Spine

Aims: Based on modern MR imaging, we consider the true dumbbell spinal tumors to have an intradural component within the spinal canal, expanding through the neural foramen and forming an extradural component paraspinally. Surgical treatment of these tumors is challenging in the subaxial cervical spine. In standard posterior approach the resection of extradural component integrity of the facet joint must be sacrifice with risk for instability. Additionally, the proximal control of the adjacent vertebral artery is impossible in event of a vessel injury. We describe a simplification of retrojugular technique which enables one stage gross total resection of the dumbbell tumors as described above with neither mobilization of vertebral artery (VA) nor spinal stabilization. Dural reconstruction was performed using mobilized local vascularized muscle flap.

Epithelioid sarcoma of the spine: Case report and literature review

Epithelioid sarcomas are rare mesenchymal neoplasms mainly arising in the limbs of young adults. We report the case of a 24-year-old male presenting low back pain radiating to both lower limbs, constipation and urinary retention. The MRI scan showed an intraspinal lesion extending from L4 to S2. Surgery resulted in gross total removal of the extradural lesion and partial removal of the intradural component. The immunohistological study of the lesion was consistent with an epithelioid sarcoma. The patient was submitted to radiotherapy and chemotherapy, but a local recurrence of the lesion and dissemination along the neuraxis were observed 3 months after surgery. Despite treatment, the patient died 4 months after the surgical procedure due to multiorgan failure. Despite there being isolated reports of epithelioid sarcomas appearing in the spine, this is, to our knowledge, the first case with intradural extension.

Spinal lobular capillary hemangioma with an intramedullary component

Capillary hemangiomas are benign vascular neoplasms rarely involving the spinal cord, where their usual location is extramedullary. A 59-year-old man presented with a 7-month history of progressive numbness which began in the left lower extremity and progressed across the lower back, right flank, trunk and into the right lower extremity with associated pressure and pain in his lower back. On magnetic resonance imaging, there was an avidly-enhancing thoracic intradural lesion that contained an extramedullary intradural component posteriorly, with an apparent intramedullary component anteriorly. Laminectomy of T7 - 8 was performed, and intradural exploration revealed a highly vascular-appearing tumor below the arachnoid, which was not completely dissected because it was densely adherent to the spinal cord. The pathological diagnosis was lobular capillary hemangioma with extra- and intramedullary components. We suggest this lesion should be considered in the differential diagnosis of spinal cord tumors with an intramedullary component.

C2 root nerve sheath tumors management

Upper cervical nerve sheath tumors (NST) arising mainly from C2 root and to lesser extent from C1 root are not uncommon, they constitute approximately 5-12% of spinal nerve sheath tumors and 18-30% of all cervical nerve sheath tumors, unique in presentation and their relationship to neighbouring structures owing to the discrete anatomy at the upper cervical-craniovertebral region, and have atendency for growth reaching large-sized tumors before manifesting clinically due to the capacious spinal canal at this region; accordingly the surgical approaches to such tumors are modified. The aim of this paper is to discuss the surgical strategies for upper cervical nerve sheath tumors. Eleven patients (8 male and 3 females), age range 28-63 years, with C2 root nerve sheath tumors were operated upon based on their anatomical relations to the spinal cord. The magnetic resonance imaging findings were utilized to determine the surgical approach. The tumors had extra- and intradural components in 10 patients, while in one the tumor was purely intradural. The operative approaches included varied from extreme lateral transcondylar approach(n = 1) to laminectomy, whether complete(n = 3) a or hemilaminectomy(n = 7), with partial facetectomy(n = 7), and with suboccipital craniectomy(n = 2). The clinical picture ranged from spasticity (n = 8, 72,72 %), tingling and numbness below neck (n = 6, 54,54 %), weakness (n = 6, 54,54 %), posterior column involvement (n = 4, 26,36 %), and neck pain (n = 4, 36,36 %). The duration of symptoms ranged from 1 to 54 months, total excision was performed in 7 patients; while in 3 patients an extraspinal component, and in 1 patient a small intradural component, were left in situ. Eight patients showed improvement of myelopathy; 2 patients maintained their grades. One poor-grade patient was deteriorated. The surgical approaches for the C2 root nerve sheath tumors should be tailored according to the relationship to the spinal cord, determined by magnetic resonance imaging.

Spinal arachnoid cysts in the pediatric population: report of 31 cases and a review of the literature

The goal of this study was to review all cases of pediatric spinal arachnoid cysts (SACs) surgically treated at the authors' institution between 1992 and 2008 and to compare these cases to the published literature for the general population. The charts of all pediatric patients with SACs were reviewed for demographics, medical history, presenting symptoms, imaging findings, operative procedure(s), complications, and outcomes. Following a complete literature review, the pediatric data were compared with data from the general population and unique findings associated with pediatric patients were identified. Thirty-one pediatric patients (median age 6.9 years) underwent operative intervention for SACs between 1992 and 2008 (median duration of follow-up 4.2 years). There were 17 female patients (55%) and 14 male patients (45%). Twenty-one patients (68%) presented with symptoms of radiculopathy or myelopathy. The most common presenting symptoms were pain (42%), lower-extremity weakness (39%), gait instability (32%), spasticity (19%), sensory loss (10%), and bladder dysfunction (7%). In 3 patients (10%) SACs were incidental findings. Intradural SACs were more common (18 patients, 58%) than extradural SACs (11 patients, 36%). One patient (3%) had extradural and intradural components. One patient (3%) had a purely intramedullary cyst, and 1 patient (3%) had both an intradural and intramedullary component. Of the 18 intradural SACs, 9 (50%) were located ventral to the spinal cord and 9 (50%) were dorsally situated. One dorsal intradural SAC had an intramedullary component. All extradural SACs were located dorsal to the spinal cord. Intradural SACs were primarily concentrated in the cervical and thoracic regions (67%), whereas extradural cysts were more evenly distributed between the thoracic, lumbar, and sacral regions. Of the 18 patients with intradural SACs, 13 (72%) had significant previous CNS abnormalities, compared with 3 (27%) of 11 patients with extradural SACs. There were 2 operative complications. One patient had a CSF leak treated with a lumbar drain, and the second patient had a pseudomeningocele. No patients had neurological deterioration as a result of surgical intervention. Twenty-one patients (68%) had complete remission of symptoms, 6 (19%) had improvement, 3 (10%) were stable, and 1 (3%) has worsening of symptoms with recurrence that ultimately required cystoperitoneal shunting, despite multiple failed attempts at fenestration. Spinal arachnoid cysts are rare lesions in the pediatric population. Affected patients present with back pain, weakness, and/or gait instability. In children, SACs predominantly develop in the thoracic region and are more likely to occur intradurally, compared with SACs in the general population. Overall outcomes following surgical fenestration or excision of SACs are excellent, with complete remission or improvement of symptoms achieved in 87% of cases.

Spontaneous resolution of an infantile hemangioma in a dorsal root ganglion

Infantile hemangiomas are tumors commonly seen in children. Few authors have reported infantile hemangiomas affecting the CNS, and there are no prior reports detailing spontaneous resolution of a histologically proven juvenile hemangioma within a dorsal root ganglion. The authors report the case of a newborn boy with a large cutaneous hemangioma in the midline of his back. Spinal MR images were obtained to rule out associated spinal cord tethering, and an intradural spinal lesion was unexpectedly discovered. Biopsy revealed an intradural infantile hemangioma within the dorsal root ganglion, and, based on this diagnosis, no resection was performed. Sixteen months following the biopsy, the cutaneous hemangioma had become involuted and the intradural hemangioma had completely resolved. The behavior of the intradural component in this case follows the natural history of many cutaneous infantile hemangiomas.

Bilateral Persistent Primitive Trigeminal Arteries Associated with Trigeminal Neuralgia

Persistent carotid-vertebrobasilar anastomoses (PCVBA) include the primitive trigeminal artery (PTA), the primitive otic artery (POA), the primitive hypoglossal artery and proatlantal arteries (ProAs). The PTA is the most commonly seen of these accounting for approximately 80-85% of PCVBAs. The PTA which connects the internal carotid artery (ICA) to the basilar artery (BA) may occasionally connect to the superior or posterior inferior cerebellar arteries without interposition to the BA. It is then referred to as a persistent trigeminal artery variant (PTAV), an anomalous carotid-cerebellar anastomosis. Bilateral occurrence of PTA is extremely rare. During vertebral artery (VA) development the anterior radicular artery of segment C1 from the proatlantal artery of Padget evolves into the intradural component of the VA (V4 segment) plus a short extradural segment (distal V3 segment). Agenesis of a single anterior radicular artery of ProA results in the absence of one distal VA associated with an unremarkable contralateral VA and the BA. Absence or hypoplasia of the terminal portion of one VA is a commonly observed anatomic variant. However, absence of the terminal portions of both VAs is exceptional. A rare case of bilateral PTAs is presented with unilateral PTA and a contralateral PTAV causing trigeminal neuralgia. Furthermore, the bilateral PTAs were associated with the absence of the proximal portion of the BA in addition to the bilateral lack of a distal VA. This finding comes as a logical consequence of the developmental anatomy of the vertebrobasilar junction and is consistent with the assumed congenital nature of the anatomic variant.