Dysphagia as a primary manifestation of basilar impression: A case report.

Secondary basilar invagination or basilar impression is an anomaly at the craniovertebral junction where the odontoid process prolapses into the foramen magnum with the risk of compressing adjacent structures and obstructing the proper flow of cerebrospinal fluid (CSF). The incidence is less than 1% in the general population and occurs mainly in the first three decades of life when it is associated with malformations of the neuroaxis. In older age, the main aetiologies are diseases that alter bone mineral density. The clinical course is usually progressive and the most common symptoms are asthenia, cervical pain and restricted movement, but also dysphonia, dyspnoea and dysphagia. It is a progressive disease which, if left untreated, can cause severe neurological damage and death. We report the case of a 79-year-old woman with osteoporosis and progressive dysphagia leading to severe malnutrition, which conditioned the decision not to intervene due to the high perioperative risk.

A novel classification and management scheme for craniocervical junction disorders with ventral neural element compression.

OBJECTIVE: Craniocervical junction (CCJ) pathologies with ventral neural element compression are poorly understood, and appropriate management requires accurate understanding, description, and a more uniform nomenclature. The aim of this study was to evaluate patients to identify anatomical clusters and better classify CCJ disorders with ventral compression and guide treatment. METHODS: A retrospective review of adult and pediatric patients with ventral CCJ compression from 2008 to 2022 at a single center was performed. The incidence of anatomical abnormalities and compressive etiologies was assessed. Surgical approach, radiographic data, and outcomes were recorded. Association rules analysis (ARA) was used to assess variable clustering. RESULTS: Among 51 patients, the main causes of compression were either purely bony (retroflexed dens [n = 18]; basilar invagination [BI; n = 13]) or soft tissue (degenerative pannus [n = 16]; inflammatory pannus [n = 2]). The primary cluster in ARA was a retroflexed dens, platybasia, and Chiari malformation (CM), and the secondary cluster was BI, C1-2 subluxation, and reducibility. These, along with degenerative pannus, formed the three major classes. In assessing the optimal treatment strategy, reducibility was evaluated. Of the BI cases, 12 of the 13 patients had anterolisthesis of C1 that was potentially reducible, compared with 2 of the 18 patients with a retroflexed dens (both with concomitant BI), and no pannus cases. The mean C1-2 facet angle was significantly higher in BI at 32.4°, compared with -2.3° in retroflexed dens and 8.1° in degenerative pannus (p < 0.05). Endonasal decompression with posterior fixation was performed in 48 (94.0%) of the 51 patients, whereas posterior reduction/fixation alone was performed in 3 patients (6.0%). Of 16 reducible cases, open posterior reduction alone was successful in 3 (60.0%) of 5 cases, with all successes containing isolated BI. Reduction was not attempted if vertebral anatomy was unfavorable (n = 9) or the C1 lateral mass was absent (n = 5). The mean follow-up was 28 months. Symptoms improved in 88.9% of patients and were stable in the remaining 11.1%. Tracheostomy and percutaneous G-tube placement occurred in 7.8% and 11.8% of patients, respectively. Reoperation for an endonasal CSF leak repair or posterior cervical wound revision both occurred in 3.9% of patients. CONCLUSIONS: In classifying, one cluster caused decreased posterior fossa volume due to an anatomical triad of retroflexed dens, platybasia, and CM. The second cluster caused pannus formation due to degenerative hypertrophy. For both, endonasal decompression with posterior fixation was ideal. The third group contained C1 anterolisthesis characterized by a steep C1-2 facet angle causing reducible BI. Posterior reduction/fixation is the first-line treatment when anatomically feasible or endonasal decompression with in situ posterior fixation when anatomical constraints exist.

Anatomical evaluation of the craniovertebral junction on cone-beam computed tomography images.

INTRODUCTION: There are many craniometric measurements that are used in evaluating craniovertebral junction (CVJ) pathologies such as basilar invagination, atlantoaxial dislocation and platybasia. Therefore, it is important to determine the normal reference range of the craniometric measurements. This study aims to determine the morphometric reference values of the bony structures in the CVJ from cone-beam computed tomography (CBCT) images of a group of South Eastern Anatolian population. MATERIALS AND METHODS: The CBCT images of 300 individuals were retrospectively evaluated. 14 parameters on midsagittal and 2 parameters on the coronal plane were studied. The data were statistically evaluated. RESULTS: Measurement results were found as follows; the distances between odontoid process (OP) and McGregor line as 0.31 ± 3.22 mm, OP and Chamberlain line 1.06 ± 3.22 mm, OP and McRae line 5.30 ± 1.59 mm, OP and Fischgold digastric line 8.70 ± 4.12 mm, OP and Fischgold bimastoid line - 5.15 ± 4.86 mm, length of McRae line 35.58 ± 2.52 mm, atlantodental interval 1.28 ± 0.48 mm, posterior atlantodental interval 19.54 ± 2.24 mm, basion axial interval 4.01 ± 1.83 mm, basion dental interval 4.92 ± 1.77 mm, length of Modified Ranawat line 28.66 ± 2.38 mm, length of Redlund-Johnell line 35.11 ± 4.09 mm, clivus canal angle 157.62° ± 11.85°, Welcher basal angle 130.83° ± 6.29°, craniocervical tilt 126.98° ± 12.24° and Powers ratio as 0.72 ± 0.06. CONCLUSION: In this study, the morphometric values were evaluated according to age and gender in individuals who did not have any radiologic anomalies. The normal reference ranges may be useful for researchers who are researching pathology in this region. It is recommended to conduct further studies with different populations to determine the normal reference range.

Clivopalate angle: a new diagnostic method for basilar invagination at magnetic resonance imaging.

OBJECTIVES: To investigate the diagnostic value of clivopalate angle (CPA) for basilar invagination (BI) at magnetic resonance imaging (MRI). METHODS: In this retrospective case-control study, CPA, clivodens angle (CDA), and clivoaxial angle (CXA) were measured on midsagittal MR images from 112 patients with BI (22 men; mean age, 43.9 years ± 13.1 years; range, 21-79 years) and 200 control subjects (57 men; mean age, 47.1 years ± 13.3 years; range, 20-80 years). Intraclass correlation coefficient (ICC), linear regression, Mann-Whitney U test, binary logistic regression, and receiver operating characteristic (ROC) curve were used for statistical analysis. RESULTS: Clivopalate angle showed better inter-observer agreement (ICC = 0.951) than CXA (0.867) or CDA (0.853). CPA significantly correlated with CXA (R = 0.811, p < 0.001) and CDA (R = 0.716, p < 0.001). Patients with BI had a significantly smaller CPA (45.9° ± 9.9°) than control subjects (61.9° ± 6.2°) (p < 0.001). With the optimal cutoff value of 53.5°, CPA had a sensitivity of 0.839 (94/112) and a specificity of 0.915 (183/200). The area under the ROC curve (AUC) was 0.937 (95% CI, 0.911-0.963) for CPA, which was similar to that of CXA (AUC, 0.957; 95% CI, 0.936-0.978) or CDA (AUC, 0.925; 95% CI, 0.892-0.957). The combination of CPA and CDA or CXA showed a higher diagnostic value than CDA or CXA alone. CONCLUSIONS: The diagnostic performance of CPA was similar to that of CXA or CDA, but CPA might be more reliable in evaluation of BI. CPA provided complementary information to CXA and CDA. KEY POINTS: • Clivopalate angle has a high diagnostic value for basilar invagination. • Clivopalate angle demonstrates high inter-reader agreement than does clivoaxial angle or clivodens angle. • Clivopalate angle provides complementary information to clivoaxial angle and clivodens angle.

Visual and Positional Modulation of Pendular Seesaw Nystagmus: Implications for the Mechanism.

BACKGROUND: The mechanisms of pendular seesaw nystagmus (SSN) remain unknown. METHODS: We evaluated modulation of pendular SSN by removal of visual fixation, convergence, and positional changes in 2 patients, one with bitemporal hemianopia due to a traumatic damage of the optic chiasm and the other with platybasia compressing the medulla and lower cerebellum. RESULTS: In both patients, the pendular SSN markedly decreased or disappeared with convergence, without visual fixation in darkness, during static head tilt toward each shoulder while sitting and while supine. CONCLUSIONS: The similar patterns of nystagmus modulation observed in our patients with a different etiology indicate a common role of both visual and otolithic inputs in generating pendular SSN.

[The rheumatic cervical spine]. / Die rheumatische Halswirbelsäule.

BACKGROUND: The cervical spine is one of the main sites of manifestation in rheumatoid arthritis outside of the extremities. It can have a decisive influence on disease course via the occurrence of mechanical instabilities as well as neurologic symptoms. Both adequate diagnosis and the corresponding surgical treatment represent a challenge for the involved physicians. MATERIALS AND METHODS: This review presents relevant diagnostic strategies and possibilities for surgical intervention which aim to avoid potentially fatal neurologic symptoms. Basic literature and expert opinions are also discussed. RESULTS AND CONCLUSION: Through target-oriented surgical management, as well as tight clinical and radiologic monitoring during conservative and surgical therapy, potentially fatal disease courses can be avoided.

Platybasia and Klippel Feil-syndrome: case report.

A case is presented of a 35-year-old woman diagnosed with platybasia associated with Klippel-Feil syndrome type I. She was admitted to University Department of Neurology for clinical examination because of walking difficulties, dizziness, and intermittent vision disturbances. Neurological examination revealed a predominance of cerebellar symptomatology. Relevant diagnostic work-up included craniogram, cervical spine x-ray, computed tomography (CT) of the brain and craniocervical junction, magnetic resonance imaging of the brain, electroencephalography, ophthalmologic examination, urinary tract ultrasonography, laboratory tests, and psychological testing. CT of the craniocervical junction showed platybasia, congenital fusion of the second and third cervical vertebrae, and basilar invagination of dens axis. Platybasia is leveling of the angle between the floor of the anterior cranial fossa and posterior cranial fossa in the area of sella turcica, which is normally at 115-140 degrees. Basilar impression or invagination is moving up of the basis of the occiput and occipital condyles into the cranium, which means that the borders of the foramen magnum, condyles and adjacent bone are invaginated into the posterior fossa. Klippel-Feil syndrome type II is massive fusion of two of seven cervical vertebrae associated with short neck and low hair line.

A rare case of basilar impression.

A teenage girl presented with progressively worsening neck and occipital pain since 8 months ago that was associated with restriction of neck movements, low to moderate grade fever, anorexia and weight loss followed by gradually progressive quadriparesis since 3 months ago. Neurological examination revealed spastic quadriparesis without cranial nerve palsy. MRI of the cervical spine revealed prevertebral and paravertebral abscess from clivus to C2/C3 level, which extended into the anterior epidural space at C1-C3 level, causing atlantoaxial dislocation. There was evidence of basilar invagination. The dislocated dens caused compression over the cervicomedullary junction. On this basis, a diagnosis of craniovertebral junction Pott's disease was made. The patient was given neck immobilisation with cervical collar, and antitubercular treatment was started. She showed significant improvement in her neurological deficit during follow-up.

Giant intradiploic pseudomeningocele of occipital bone.

The management of intradiploic CSF collection is controversial. Although it is a benign lesion, even then delay in diagnosis and treatment may lead to significant morbidity. The authors report a very rare case of giant posttraumatic intradiploic pseudomeningocele involving the occipital bone, occipital condyles, and clivus. The pathogenesis and management of intradiploic CSF collection are discussed. This 16-year-old boy presented with a history of enlarging swelling in the suboccipital region associated with headache, lower cranial nerve palsy, and features of high cervical compressive myelopathy. Investigations revealed a giant intradiploic lesion involving the occipital bone, condyles, and clivus associated with secondary basilar invagination, hydrocephalus, and syringomyelia. Intrathecal contrast administration did not reveal communication of intradiploic space with the subarachnoid space. A large occipital craniotomy was performed. A linear fracture and dural defect in the midline was identified, which was closed with fascial graft after removing the inner table of the skull. Cranioplasty was performed using the expanded calvarial bone. Ventriculoperitoneal shunt insertion was performed for hydrocephalus, and the patient improved remarkably. Posttraumatic intradiploic CSF collection, although a benign condition, may present with severe complications if treatment is delayed. Early diagnosis and treatment is essential. The authors suggest that this condition should be treated early, as for growing skull fractures.

Posterior occipitocervical fixation under skull-femoral traction for the treatment of basilar impression in a child with Klippel-Feil syndrome.

We present the case of a 15-year-old boy with symptoms due to Klippel-Feil syndrome. Radiographs and CT scans demonstrated basilar impression, occipitalisation of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Skull traction was undertaken pre-operatively to determine whether the basilar impression could be safely reduced. During traction, the C3/C4 junction migrated 12 mm caudally and spasticity resolved. Peri-operative skull-femoral traction enabled posterior occipitocervical fixation without decompression. Following surgery, cervical alignment was restored and spasticity remained absent. One year after surgery he was not limited in his activities. The surgical strategy for patients with basilar impression and congenital anomalies remains controversial. The anterior approach with decompression is often recommended for patients with ventral compression of the medullocervical region, but such procedures are technically demanding and carry a significant risk of complications. Our surgical strategy was an alternative solution. Prior to a posterior cervical fixation, without decompression, skull traction was used to confirm that the deformity was reducible and effective in resolving associated myelopathy.

The role of cephalometry in assessing velopharyngeal dysfunction in velocardiofacial syndrome.

OBJECTIVE: To report our experience with cephalometry in evaluating velopharyngeal dysfunction (VPD) in velocardiofacial syndrome (VCFS) and its utility in assessing the role of cervical spine abnormalities in VPD, prior to surgical correction of VPD. DESIGN: Clinical charts and cephalometric radiographs done prior to surgery for VPD were retrospectively analyzed to ascertain velopharyngeal measurements and cervical spine abnormalities. PATIENTS: Twenty-six patients (age: 6-23 years) with molecularly confirmed VCFS. SETTING: Wake Forest University Health Sciences (1997-2005). MEASUREMENTS: Cranial base angle, nasopharyngeal depth, velum length, and Need ratio at rest, velar dimple location, and velopharyngeal length during phonation; information on presence/absence of submucous cleft palate and cervical spine abnormalities were also obtained. The relationship between C1 anterior arch abnormalities and Need ratio was examined. RESULTS: Seventy-three percent of the VCFS patients had excessive nasopharyngeal depth, 80% had an abnormal Need ratio, 50% had a short velum, 81% had a submucous or occult submucous cleft palate, 90.5% had a cervical spine abnormality (C1 anterior arch abnormalities in 38%) and 11.5% had platybasia. There was a significant difference in the Need ratio between patients with and without C1 anterior arch abnormalities. CONCLUSION: Cephalometry can be used to delineate factors such as C1 vertebral abnormalities, excessive pharyngeal depth, and short velum that contribute to VPD in VCFS. This would help otolaryngologists better understand the anatomy prior to surgical treatment of VPD. This is the first study to highlight the frequent occurrence of C1 anterior arch abnormalities in VCFS.

Placement of occipital condyle screws for occipitocervical fixation in a pediatric patient with occipitocervical instability after decompression for Chiari malformation.

In cadaveric studies and recently in one adult patient the occipital condyle has been studied as an option to allow bone purchase by fixation devices. In the current case the authors describe the use of occipital condyle screws in a child undergoing occipitocervical fixation. To the best of the authors' knowledge this case is the first reported instance of this technique in a pediatric patient. This girl had a history of posterior fossa decompression for Chiari malformation Type I when she was 22 months of age. When she was 6 years old she presented with neck pain on flexion and extension of her head. Magnetic resonance imaging in flexion and extension revealed occipitocervical instability. She underwent an occiput to C-2 posterior arthrodesis with bilateral screw placement in the occipital condyles, C-2 lamina, and C-1 lateral masses. Postoperatively, she was neurologically intact. Computed tomography demonstrated a stable construct, and her cervical pain had resolved on follow-up.

Syringomyelia with irreducible atlantoaxial dislocation, basilar invagination and Chiari I malformation.

A 27-year-old woman presented with bilateral weakness of her all extremities for 5 years. She had a spastic gait and was unable to ambulate without assistance. Neurologic examination revealed increased deep tendon reflexes and positive pathologic reflexes. Radiographs showed occipitalization of the atlas, C2-C3 congenital fusion and fixed atlantoaxial dislocation with an atlanto-dental interval of 10 mm. MRI demonstrated cervicomedullary junction (CMJ) compression from the odontoid, a Chiari type I malformation, and syringomyelia extending from the foramen magnum to C5. The patient underwent transoral atlantoaxial release followed by posterior internal fixation from the occiput to the axis, which resulted in a significant improvement in motor function in all extremities. Post-operative images showed anatomical reduction of the atlantoaxial joint. However, an MRI performed 8 days following surgery showed a new retro-odontoid pannus had developed that was compressing the spinal cord at CMJ. A follow-up CT scan performed at 6 months post-operatively demonstrated a solid bony fusion between the occiput and C2, while an MRI at that time showed complete resolution of the retro-odontoid soft tissue mass with correction of the Chiari I malformation, and resolution of the syringomyelia. Final follow-up at 2-years revealed an excellent clinical outcome.

Basilar invagination, Chiari malformation, syringomyelia: a review.

Institute and personal experience (over 25 years) of basilar invagination was reviewed. The database of the department included 3300 patients with craniovertebral junction pathology from the year 1951 till date. Patients with basilar invagination were categorized into two groups based on the presence (Group A) or absence (Group B) of clinical and radiological evidence of instability of the craniovertebral junction. Standard radiological parameters described by Chamberlain were used to assess the instability of the craniovertebral junction. The pathogenesis and clinical features in patients with Group A basilar invagination appeared to be related to mechanical instability, whereas it appeared to be secondary to embryonic dysgenesis in patients with Group B basilar invagination. Treatment by facetal distraction and direct lateral mass fixation can result in restoration of craniovertebral and cervical alignment in patients with Group A basilar invagination. Such a treatment can circumvent the need for transoral or posterior fossa decompression surgery. Foramen magnum bone decompression appears to be a rational surgical treatment for patients having Group B basilar invagination. The division of patients with basilar invagination on the basis of presence or absence of instability provides insight into the pathogenesis of the anomaly and a basis for rational surgical treatment.

Transoral approach and its superior extensions to the craniovertebral junction malformations: surgical strategies and results.

OBJECTIVE: To review our experience with the surgical management of craniovertebral junction malformations, focusing on the selection of surgical approach, management of the associated Chiari malformation, and postoperative instability. METHODS: During a 7-year period (May 2000-May 2007), 34 patients with a mean age of 55 years (age range, 32-75 years) underwent transoral surgery for fixed or nearly fixed ventral compression at the craniovertebral junction caused by basilar invagination and/or atlantoaxial dislocation. Chiari malformation was detected in 13 patients. The most common presenting signs were motor deficits (88%), followed by sensory loss (35%). All patients but one who had posterior stabilization performed elsewhere underwent single-stage anterior decompression and posterior occipitocervical fixation. Adjuncts to the transoral approach were tailored to the local anatomy (severity of basilar invagination, extent of mandibular excursion) found in each patient. Posterior fossa decompression was performed in 3 patients with Chiari malformation. RESULTS: Thirty-one patients were alive at the time of the last follow-up evaluation (average, 3.7 years; range, 0.5-7.5 years). Of the 28 surviving patients admitted with preoperative motor impairment, 24 patients (86%) improved at least 1 Nurick grade, whereas the grade did not change in 4 (14%) patients. There were 2 (6%) perioperative deaths, and 1 other patient died subsequently of causes unrelated to surgery. Surgical morbidity was 18% and included dural laceration, cerebrospinal fluid leak with meningitis, malocclusion, oral wound dehiscence, and occipital wound infection. Delayed instability occurred in 1 patient because of cranial settling of the C2 vertebral body. CONCLUSION: Successful decompression of the abnormal craniovertebral junction requires extensive preoperative evaluation, appropriate tailoring of the operative approach, and an adequate learning curve. Transmaxillary approaches are useful adjuncts to the transoral approach in patients with severe basilar invagination or in cases of limited jaw mobility. Anterior decompression has been proven effective in relieving obstruction of the subarachnoid space at the foramen magnum in most patients with associated Chiari malformation.

Endoscopic transnasal decompression for management of basilar invagination in osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a disorder of bone development caused by a genetic dysfunction of collagen synthesis. Basilar invagination (BI) is an uncommon but serious complication of OI. Brainstem decompression in OI is undertaken in certain circumstances. Transoral-transpalatopharyngeal ventral decompression with posterior occipitocervical fusion has become the treatment of choice when required. This technical note outlines a novel endoscopic transnasal approach for ventral decompression. The literature is reviewed and a strategy for the management of BI in patients with OI is outlined.

Basilar impression and osteogenesis imperfecta: a 21-year retrospective review of outcomes in 20 patients.

OBJECT: Basilar impression (BI) secondary to osteogenesis imperfecta (OI) is a rare but debilitating condition that is often progressive unless it is halted. More recently, ventral decompression surgery has been advocated for this condition. This study is a retrospective review of the 21-year experience of ventral decompression surgery and dorsal occipitocervical fixation in patients with BI secondary to OI and is the largest patient series reported to date. METHODS: Twenty patients treated between 1982 and 2003 by the senior author at the authors' institution were included in this study. All patients underwent ventral decompression surgery followed by dorsal craniocervical stabilization. Patients were followed up for a median of 10 years. RESULTS: There were no intraoperative or perioperative deaths. Postoperatively, 16 of 20 (80%) patients showed objective improvement or maintained their good preoperative level of function. After surgery, of the 15 patients admitted with Karnofsky Performance Scale (KPS) scores of 70% or less, 11 improved, two remained unchanged, one patient's condition deteriorated, and one patient died of an unrelated cause. Of five patients admitted with a KPS score of 80% or greater, no patient's condition deteriorated in the short- and midterm period, but one patient had recurrence 15 years after surgery. At the end of follow-up, 25% of the patients had recurrence of brainstem compression symptoms or had died, and 15% showed no improvement after surgery. All of the remaining patients (60%) had sustained a long-term benefit from surgery. CONCLUSIONS: Aggressive ventral decompression surgery and dorsal stabilization for patients with BI secondary to OI can not only halt disease progression but can also produce a good and sustainable long-term functional outcome, even in those patients who present as severely symptomatic. Patients who presented early with minor symptoms had good long-term outcomes.