Fourth ventricle to spinal subarachnoid space stenting in pediatric patients with refractory syringomyelia: case series and systematic review.

A series of 5 patients treated with the fourth ventricle to spinal subarachnoid space stent (FVSSS) is presented. Indication for surgery, surgical technique, pre-operative and post-operative images, and outcome are analyzed. A systematic review of the pertinent literature has also been performed. This is a retrospective cohort review of a series of 5 consecutive patients with refractory syringomyelia who underwent a fourth ventricle to spinal subarachnoid space shunt surgery. The surgical indication was based on the presence of refractory syringomyelia in patients already treated for Chiari malformation or in patients who developed scarring at the level of the outlets of the fourth ventricle following posterior fossa tumor surgery. The mean age at FVSSS was 11.30 ± 5.88 years. Cerebral MRI revealed crowded posterior fossa, with a membrane at the level of the foramen of Magendie. Spinal MRI showed syringomyelia in all patients. Before surgery, the averages of the craniocaudal and the anteroposterior diameter were 22.66 and 1.01 cm, respectively, whereas the volume was 28.16 cm3. The post-operative period was uneventful in 4 out of 5 patients; one child died on the 1st post-operative day due to complications unrelated to surgery. In remaining cases, syrinx marked improvement. The post-operative volume was 1.47 cm3 with an overall reduction of 97.61%. With regard to literature, 7 articles with a total of 43 patients were analyzed. After FVSSS, syringomyelia reduction was observed in 86.04% of cases. Three patients underwent reoperation due to syrinx recurrence. Four patients presented a catheter displacement, one a wound infection and meningitis and one CSF leak requiring placement of a lumbar drain. FVSSS is highly effective in restoring CSF dynamics, with dramatic improvement of syringomyelia. In all our cases, the volume of the syrinx was reduced by at least 90%, with improvement/resolution of accompanying symptomatology. This procedure should be reserved to patients in which other causes of gradient pressure between the fourth ventricle and subarachnoid space are excluded, for example, tetraventricular hydrocephalus. Surgical procedure is not simple, because it requires meticulous microdissection of cerebello-medullary fissure and upper cervical spine, in already operated patients. To avoid migration of the stent, it should be carefully sutured to the dura mater or thick arachnoid membrane.

Posterior arch reconstruction in cervical surgery to restore the global biomechanics of the Atlas: a technical note.

The posterior arch of the atlas is usually not considered one of the main stabilizers of the cranio-cervical junction, allowing surgeons to its removal when needed with a relative certainty to preserve the stability of the atlo-axial segment. However, these considerations do not reflect the importance to examine the integrity of the posterior arch in the whole biomechanics of the atlas. Authors like Gebauer and Panjabi revealed, respectively in experimental and clinical conditions, how the atlas responds to an axial loading force, proving that the whole atlas is involved into horizontal conversion of axial forces and providing evidence supporting the preservation of the posterior arch. Other authors evaluated the risk for anterior arch fracture following C1 laminectomy. In this technical note three different techniques of posterior atlas arch reconstruction after surgical iatrogenic disruption are presented, considering both neoplastic and degenerative disease.

The loneliness of a long-distance runner. A ten-year survey of a patient diagnosed with Gorham-Stout syndrome at the occipitocervical junction.

This case study presents a 47-year-old male who was diagnosed with Gorham-Stout syndrome (GSS) 10 years ago in the occipitocervical junction. The pathology caused the resorption of the suboccipital bone, clivus, foramen magnum, and C1-C3 laminae. After his first fusion attempt in 2010 using occipital plate-cervical lateral mass screws, he needed many revision surgeries either for the progression of the pathology or for instrumentation failure and wound healing problems. Eventually, a new occipital plate and cervical pedicle screws were applied to obtain the exact solution. The involvement of the craniovertebral junction in GSS may be challenging for spinal surgeons due to the inadequate bone reserve for stabilization. As lateral mass screws cannot provide a strong pull-out force, cervical pedicular screws may be used as the first choice for unstable cervical GSS cases.

Traumatic occipito-cervical dissociation in adults: a Middle Eastern cohort study.

The objective of this study is to describe a series of cranio-cervical dissociation victims and evaluate their outcomes as well as discuss the clinical dilemmas we faced in the context of current literature evidence. This is a retrospective cohort study of traumatic occipito-cervical dissociation in five patients (three males and two females) encountered between 2010 and 2016 at a tertiary care facility in the Middle East region. All patients underwent occipito-cervical fusion using screws and rods system with mean postoperative follow-up period of 2.5 years. All patients survived, and four were independently mobile and one wheel chair bound. Most had some degree of neurological sequelae, often due to associated injuries and all complained of limited neck range of motion. Contemporary literature review shows that CT scan with MRI is often the best diagnostic modality. Surgery is usually indicated though rare cases treated conservatively have been reported. The commonest predictor of mortality is missed injury, associated head injury and wide separation between the skull base and C1 on imaging studies.

Co-occurrence of tethered cord syndrome and cervical spine instability in hypermobile Ehlers-Danlos syndrome.

The Ehlers-Danlos Syndromes (EDS) represent a group of hereditary connective tissue disorders, with the hypermobile subtype (hEDS) being the most prevalent. hEDS manifests with a diverse array of clinical symptoms and associated comorbidities spanning the musculoskeletal, neurological, gastrointestinal, cardiovascular, and immunological systems. hEDS patients may experience spinal neurological complications, including cervico-medullary symptoms arising from cranio-cervical and/or cervical instability/hypermobility, as well as tethered cord syndrome (TCS). TCS is often radiographically occult in nature, not always detectable on standard imaging and presents with lower back pain, balance issues, weakness in the lower extremities, sensory loss, and bowel or bladder dysfunction. Cervical instability due to ligament laxity can lead to headaches, vertigo, tinnitus, vision changes, syncope, radiculopathy, pain, and dysphagia. TCS and cervical instability not only share clinical features but can also co-occur in hEDS patients, posing challenges in diagnostics and clinical management. We present a review of the literature and a case study of a 20-year-old female with hEDS, who underwent surgical interventions for these conditions, highlighting the challenges in diagnosing and managing these complexities and underscoring the importance of tailored treatment strategies to improve patient outcomes.

Human genetics and molecular genomics of Chiari malformation type 1.

Chiari malformation type 1 (CM1) is the most common structural brain disorder involving the craniocervical junction, characterized by caudal displacement of the cerebellar tonsils below the foramen magnum into the spinal canal. Despite the heterogeneity of CM1, its poorly understood patho-etiology has led to a 'one-size-fits-all' surgical approach, with predictably high rates of morbidity and treatment failure. In this review we present multiplex CM1 families, associated Mendelian syndromes, and candidate genes from recent whole exome sequencing (WES) and other genetic studies that suggest a significant genetic contribution from inherited and de novo germline variants impacting transcription regulation, craniovertebral osteogenesis, and embryonic developmental signaling. We suggest that more extensive WES may identify clinically relevant, genetically defined CM1 subtypes distinguished by unique neuroradiographic and neurophysiological endophenotypes.

Chiari type I malformation discovered through a glossopharyngeal neuralgia.

Glossopharyngeal neuralgia is a rare disease whose initial treatment is pharmacological. When medical therapy is not effective, different surgical options are available including stereotactic radiosurgery, microvascular decompression or nerve section. It is reported a case of a 26-year-old female with glossopharyngeal neuralgia and Chiari malformation. This rare type of neuralgia sometimes is associated with an abnormality of the cranio-cervical junction. It was performed a posterior fossa expansion with duraplasty and microvascular decompression. The patient showed a complete disappearance of the pain, with no need of tonsil resection.

Evaluation of using the Anderson-Montesano and the Tuli classifications in pediatric patients with occipital condyle fractures.

BACKGROUND: Occipital condyle fractures (OCFs) in patients before 18 years of age are rare. Classifications of OCF are based on the CT images of the cranio-cervical junction (CCJ) and MRI. The Anderson-Montesano and Tuli classifications are the types which are most commonly used in these cases. Classification of OCFs allows the implementation of OCF treatment. The aim of this study was to evaluate the effectiveness of using the OCF classification in pediatric patients based on the analysis of our own cases. METHODS: During the years 2013-2020, 6 pediatric patients with OCFs, aged 14-18, have been treated. Two patients with unstable fracture III according to Anderson-Montesano and IIB according to Tuli were treated with the halo-vest. Additionally, one patient presenting neurological symptoms and with an associated C1 fracture was qualified for the halo-vest stabilization as well. The other patients were treated with a Minerva collar. We evaluated the results 6 months after completing the OCF treatment using the Neck Disability Index (NDI) and SF-36 questionnaires. Confidence intervals for the mean values were verified using the MeanCI function (from the R library DescTools) for both classical and bootstrap methods. RESULTS: Based on NDI results, we have obtained in our patients an average of 4.33/45 points (2-11) and 9.62% (4.4-24.4). Based on the SF-36 questionnaire, we obtained an average of 88.62% (47.41-99.44). CONCLUSION: The Anderson-Montesano and Tuli's classifications of OCF can be used to assess the stability of OCF in adolescents, but both classifications should be used simultaneously. CT and MR imaging should be used in diagnosing OCFs, whereas CT allows assessing therapeutic outcomes in OCF.

Course variability of the atlantic (V3) segment of vertebral artery: anatomical study with clinical implications.

BACKGROUND: The atlantic segment of vertebral artery (V3) located at the centre of the cranio-vertebral junction is known for its variability and asymmetry, and is either the target or on the way of numerous procedures in this region. The aim of the study was to visualise variability of V3 segment. MATERIALS AND METHODS: The V3 segment was studied in 49 specimens of the suboccipital region injected with coloured gelatine. Direct measurements were performed and probabilistic maps were created using digital photography. RESULTS: The V3 segment has wavy course with possible lateral and significant postero-inferior expansions. In relation to the foramen transversarium the V3 reached up to 5 mm laterally, 23 mm posteriorly, 27 mm medially and up to 11 mm downward. Looking from the medial aspect the course of the V3 is less predictable compared to the lateral approach. Linear measurements and probabilistic maps revealed significant variability and large range of variation. There were 11 cases of V3 tortuosity found in studied material. CONCLUSIONS: The complex and variable spatial conformation of V3 makes individual diagnostic and preoperative approach necessary.

Case Report: A Rare Case of Fourth Ventricle to Spinal Subarachnoid Space Shunt Migration: Surgical Pearl and Literature Review.

Background: In the event of syringomyelia communicating with the fourth ventricle, a fourth ventricle to cervical subarachnoid space shunting could be proposed. Case Report: In this review article, we describe the case of a 40-year-old woman who had a previously implanted fourth ventricle to spinal subarachnoid space shunt for the treatment of syringomyelia in the context of Chiari syndrome. The catheter migrated intradurally to the lumbosacral space, but in the absence of neurological repercussions, we decided to leave it in place. Conclusions: To the best of our knowledge, this is the first case described in the literature review of a catheter migration in the subarachnoid space from occipitocervical to lumbosacral level.

Cervical myelopathy caused by ventrally located atlanto-axial synovial cysts: An open quest for the safest and most effective surgical management. Case series and systematic review of the literature.

OF BACKGROUND DATA: Despite a good understanding of the natural history of spinal synovial cysts (SCs), a widespread agreement regarding their optimal management is still lacking. This is particularly true for SCs occurring at the C1-C2 level, which are rare, but oftentimes lead to a rapidly evolving cervical myelopathy. METHODS: We report a series of 4 patients (M:F ratio=1:1; mean age 63.5 years) presenting with progressive cervical myelopathy secondary to ventrally located C1-C2 SCs. All patients underwent a postero-lateral facet-sparing intradural approach with total excision of the SCs. Functional status was assessed pre- and postoperatively with Nurick scale and the modified Japanese Orthopaedic association grading. Furthermore we conducted a systematic review, following PRISMA guidelines of pertinent literature to contextualize the options for surgical management of such lesions. RESULTS: Complete excision of the SCs was confirmed radiologically and on histological analysis. All measures of functional status improved post-operatively, and no cyst recurrence or need for instrumented fusion were noted during follow up (range from 22 to 88 months). CONCLUSION: Our experience suggests that the facet-sparing intradural approach provides excellent clinical outcomes without causing any C1-C2 instability. This is in keeping with the take home message emerging from our literature review, which confirms that treatment should aim at radical resection of SCs while minimizing the risk of postoperative instability.

Sinus pericranii, skull defects, and structural brain anomalies in TRAF7-related disorder.

BACKGROUND: Several somatic mutations in TRAF7 have been reported in cancers, whereas a few germline heterozygous mutations have been recently linked to a neurodevelopmental disorder, characterized by craniofacial dysmorphisms, congenital heart defects, and digital anomalies. CASES: We report two subjects harboring de novo heterozygous missense variants in TRAF7, namely the recurrent 1964G>A(p.Arg655Gln) and the novel missense c.1204C>G(p.Leu402Val) variants. In addition to the typical hallmarks of the TRAF7-related disorder, both subjects presented with a recognizable "pear-shaped" skull due to multiple craniosynostosis, sinus pericranii, skull base/cranio-cervical junction anomalies, dysgyria, and inferior cerebellar vermis hypoplasia. CONCLUSIONS: Hence, we expand the genotypic and phenotypic spectrum of this neurodevelopmental disorder, discussing possible implications for clinical management of subjects with germline TRAF7 mutations.

Global sagittal spinal alignment at cervical flexion in patients with dropped head syndrome.

PURPOSE: Dropped head syndrome (DHS) is characterized by the passively correctable chin-on-chest deformity. The characteristic feature is emphasized in the cervical flexion position. The purpose of this study was to analyze the influence of cervical flexion on sagittal spinal alignment in patients with DHS. METHODS: The study included 15 DHS subjects and 55 cervical spondylosis (CS) subjects as the control group. The following parameters were analyzed: cervical sagittal vertical axis (C-SVA), occipitoaxial angle (O-C2A), C2 slope (C2S), C2-C7 angle (C2-C7A), T1 slope (T1S), sagittal vertical axis, T1-T4 angle (T1-T4A), T5-T8 angle (T5-T8A), T9-T12 angle, lumbar lordosis, sacral slope, and pelvic tilt, in cervical flexion and neutral positions. RESULTS: The values of C-SVA, O-C2A, C2S, and T1S were significantly different between CS and DHS at cervical neutral and flexion positions. C2-C7A showed significant difference in cervical neutral position, but the difference disappeared in flexion position. T1-T4A did not present a significant difference, but T5-T8A showed a difference in neutral and flexion positions. CONCLUSIONS: Malalignment of DHS extended not only to cervical spine but also to cranio-cervical junction and thoracic spine, except T1-T4. It is known that global sagittal spinal alignment is correlated with adjacent parameters, although in DHS the reciprocal change was lost from cranio-cervical junction to the middle part of thoracic spine at cervical flexion.

Usefulness of preoperative cone beam computed tomography and intraoperative digital subtraction angiography for dural arteriovenous fistula at craniocervical junction: Technical case report.

BACKGROUND: Direct surgery is commonly selected for the treatment of cranio-cervical junction dural arteriovenous fistula and its outcome is more satisfactory than that of embolization. Intraoperative treatment evaluation is relatively easy in embolization, whereas in direct surgery it can be difficult. CASE DESCRIPTION: A 67-year-old male suffered a subarachnoid hemorrhage. On three-dimensional (3D) images of preoperational cone-beam computed tomography (CBCT), the structure of the draining vein was depicted in detail along with the surrounding bone structures. The radial artery penetrated the dura mater, and it was found that there were two veins derived from the radiculospinal vein; one was the anterior radicular vein descending toward the dorsal side (the shallow layer of the surgical field) and the other was the anterior spinal medullary vein ascending toward the ventral side (the deep layer of the surgical field) and flowing out to the anterior spinal vein. CONCLUSION: Without detailed assessments with preoperative CBCT, the surgery might have been done with dissection of only the anterior radicular vein in the shallow layers. For identification of the draining vein located deep in the surgical field, such as the cranio-cervical junction, careful assessments using 3D CBCT images are important.

Cerebrospinal fluid volumetric net flow rate and direction in idiopathic normal pressure hydrocephalus.

The aim of the present study was to examine cerebrospinal fluid (CSF) volumetric net flow rate and direction at the cranio-cervical junction (CCJ) and cerebral aqueduct in individuals with idiopathic normal pressure hydrocephalus (iNPH) using cardiac-gated phase-contrast magnetic resonance imaging (PC-MRI). An in-depth, pixel-by-pixel analysis of regions of interest from the CCJ and cerebral aqueduct, respectively, was done in 26 iNPH individuals, and in 4 healthy subjects for validation purposes. Results from patients were compared with over-night measurements of static and pulsatile intracranial pressure (ICP). In iNPH, CSF net flow at CCJ was cranially directed in 17/22 as well as in 4/4 healthy subjects. Estimated daily CSF volumetric net flow rate at CCJ was 6.9 ±â€¯9.9 L/24 h in iNPH patients and 4.5 ±â€¯5.0 L/24 h in healthy individuals. Within the cerebral aqueduct, the CSF net flow was antegrade in 7/21 iNPH patients and in 4/4 healthy subjects, while it was retrograde (i.e. towards ventricles) in 14/21 iNPH patients. Estimated daily CSF volumetric net flow rate in cerebral aqueduct was 1.1 ±â€¯2.2 L/24 h in iNPH while 295 ±â€¯53 mL/24 h in healthy individuals. Magnitude of cranially directed CSF net flow in cerebral aqueduct was highest in iNPH individuals with signs of impaired intracranial compliance. The study results indicate CSF flow volumes and direction that are profoundly different from previously assumed. We hypothesize that spinal CSF formation may serve to buffer increased demand for CSF flow through the glymphatic system during sleep and during deep inspiration to compensate for venous outflow.

Versatility of sub-occipital approach for foramen magnum meningiomas: a single centre experience.

BACKGROUND: Foramen magnum meningiomas (FMM) represent a challenge for neurosurgeons. Multiple surgical strategies have been reported to treat these lesions in their variable location. Contemporary technical innovations allow the utilization of common sub-occipital craniotomy to treat ventrally, ventro-laterally and dorsally located FMMs. We present our technique and experience. METHODS: From November 2004 to November 2015, we treated 14 patients with FMM at the Department of Neurosurgery of the Santa Maria delle Grazie Hospital in Pozzuoli, Naples, Italy. There were 10 females and 4 males, with a mean age of 64.5 years (range, 55-77 years). All patients had high field magnetic resonance imaging (MRI) with contrast enhancement preoperatively, which led to the radiological diagnosis. A sub-occipital craniotomy was performed in all patients as well as the removal of the posterior arch of C1. Partial removal of C2 was necessary in 2 patients. Neck pain was the most common symptom of presentation. Paraparesis was present in patients in 3 patients. Upper limbs dysesthesia or pain existed in 3 cases. RESULTS: Thirty days after surgery neck pain and dysesthesia decreased in all patients affected. Neurological improvement was observed in 2 patients affected by weakness in lower limbs at 6 months follow up. Paraparesis was unchanged in 1 patient. Two patients presented transient worsening after surgery. Transient dysphagia occurred in one case and postoperative hemorrhage with subsequent surgery in another patient. We had no postoperative mortality. CONCLUSIONS: FMM surgery should be tailored to the lesion at hand as in most instances it is possible to avoid the use of extensive skull base approaches.

Hemodynamic stroke: A rare pitfall in cranio cervical junction surgery.

Surgical C1C2-stabilization may be complicated by arterial-arterial embolism or arterial injury. Another potential complication is hemodynamic stroke. The latter might be induced in patients with poor posterior fossa collateralization (risk factor 1) when the vertebral artery (VA) is compressed during reduction (risk factor 2). We report a clinical case where this rare situation occurred: A 72-year old patient was undergoing C1C2-stabilization for subluxation due to rheumatoid arthritis. Preoperative computed tomography angiography (CTA) had shown poor collaterals in the posterior fossa. Furthermore, intraoperative Doppler ultrasound (US) detected unilateral VA occlusion during reduction. It appeared to be a high-risk situation for hemodynamic stroke. Surgical inspection of the VA found osteofibrous compressing elements. Arterial decompression was performed resulting in the normal flow as detected by US. Subsequently, C1C2-stabilization could be realized. The clinical and radiological outcome was very favorable. In C1C2-stabilization precise analysis of preoperative CTA and intraoperative US are important to detect risk factors of hemodynamic stroke. Using these data may prevent this rare, but potentially life-threatening complication.

Primary calcified rhabdoid meningioma of the cranio-cervical junction: A case report and review of literature.

Rhabdoid meningioma (RM) is a relatively new, rare, and aggressive subtype of meningioma, classified as Grade III malignancy in 2000, 2007 versions of WHO classification of the central nervous system. We reviewed the data available from all published cases of RMs. To the best of our knowledge, there are more than 100 published cases of RMs; none have documented extensive calcification or origin from the cranio cervical junction. We report the first case of a totally calcified (stony mass), primary RM, at the cranio cervical junction. Also, we highlighted the role of the transcondylar approach to achieve microscopic total removal of such a challenging lesion. A 37 year old female, allergic to erythromycin, presented with 5 years of progressive right upper extremity numbness and weakness, right facial numbness, and occipital pain. Imaging demonstrated a large calcified mass at the right posterior-lateral margin of the cranio cervical junction, encasing the right vertebral artery and right PICA loop. Patient underwent microscopic total resection of the lesion. Pathological diagnosis was confirmed as RM with atypical features. Subsequently, the patient received postoperative intensity modulated radiotherapy (IMRT) on the tumor bed, and close follow up imaging showed no recurrence 2 years after surgery. We report the first case of a primary RM originating from the cranial cervical junction; also, it is the first case to present with extensive calcification in this morphological subtype. We also conclude that RM has now become a feature of newly diagnosed cases and not only a disease of recurrent cases as it was thought in the past. Since RMs are typically considered aggressive, total surgical resection with close follow up and postoperative adjuvant radiation should be considered. However, the adjuvant therapy of each separate case of RM should be tailored according to its particular histopathologic profile.

A torcular encephalocele with proatlas defect and os-terminale.

Encephalocele means if meninges and brain tissue protrude out of the cranium. There are different types of encephalocele. The occipital encephaloceles are the most common type. Craniocervical junction and upper cervical spine abnormalities can rarely be associated with occipital encephalocele. We discuss this case because there is rare association between torcular encephalocele and proatlas anomalies.