A case of basilar impression surgically treated in a female patient aged 22 years is presented. A myriad of abnormal neurologic findings were present that were secondary to compression of neural tissue by anormalous bony structure at craniovertebral junction. Metrizamide computerized tomography with coronal and sagittal reconstruction identified bony abnomalities and displacement of the surrounding neural structures. The surgical intervention for the treatment of the basilar impression consisted of ventral decompression by transoral odontoidectomy and of dorsal decompression by an enlargement of foramen magnum and by laminectomy of C1, followed by occipito-atlanto-axial bony fusion.
Decompression ; Female ; Foramen Magnum ; Humans ; Laminectomy ; Metrizamide ; Neurologic Manifestations ; Platybasia*

We report a rare case of tuberculosis as a cause of secondary basilar impression. A 35-year-old man was admitted to our hospital complaining of severe neck pain and motor weakness on both sides (upper and lower limbs). CT and MRI demonstrated C1/C2 subluxation, basilar impression, and an abscess occupying the prevertebral space. We performed a single-stage operation, comprising anterior removal of the abscess, posterior fixation, and fusion. The patient was discharged five weeks after surgery without any neurologic deficits or complications. Only few reports have been published worldwide describing cases of tuberculosis as a cause of secondary basilar impression. Tuberculosis of the craniovertebral (CV) junction should be considered, especially in young patients with mid- to long-term histories of neck pain without clear origins, to allow for early intervention.
Abscess ; Adult ; Early Intervention (Education) ; Humans ; Neck Pain ; Neurologic Manifestations ; Platybasia ; Tuberculosis

Chiari type I malformation(CM-I) is a congenital disorder recognized by caudal displacement of the cerebellar tonsils through the foramen magnum and into the cervical canal. Though bony anomalies associated with CM including platybasia, small posterior fossa and occipitalization, are relatively frequent, but the incidence rate associated with agenesis of posterior arch of atlas is very low. We report our experience of surgical treatment for patient who had CM-I with unilateral agenesis of posterior arch of atlas.
Arnold-Chiari Malformation ; Congenital, Hereditary, and Neonatal Diseases and Abnormalities ; Foramen Magnum ; Humans ; Incidence ; Palatine Tonsil ; Platybasia

BACKGROUND: An abnormally obtuse cranial base angle, also known as platybasia, is a common finding in patients with 22q11.2 deletion syndrome (22q11DS). Platybasia increases the depth of the velopharynx and is therefore postulated to contribute to velopharyngeal dysfunction. Our objective was to determine the clinical significance of platybasia in 22q11DS by exploring the relationship between cranial base angles and speech resonance. METHODS: In this retrospective chart review at a tertiary hospital, 24 children (age, 4.0-13.1 years) with 22q11.2DS underwent speech assessments and lateral cephalograms, which allowed for the measurement of the cranial base angles. RESULTS: One patient (4%) had hyponasal resonance, 8 (33%) had normal resonance, 10 (42%) had hypernasal resonance on vowels only, and 5 (21%) had hypernasal resonance on both vowels and consonants. The mean cranial base angle was 136.5degrees (standard deviation, 5.3degrees; range, 122.3-144.8degrees). The Kruskal-Wallis test showed no significant relationship between the resonance ratings and cranial base angles (P=0.242). Cranial base angles and speech ratings were not correlated (Spearman correlation=0.321, P=0.126). The group with hypernasal resonance had a significantly more obtuse mean cranial base angle (138degrees vs. 134degrees, P=0.049) but did not have a greater prevalence of platybasia (73% vs. 56%, P=0.412). CONCLUSIONS: In this retrospective chart review of patients with 22q11DS, cranial base angles were not correlated with speech resonance. The clinical significance of platybasia remains unknown.
Child ; DiGeorge Syndrome* ; Humans ; Platybasia* ; Prevalence ; Retrospective Studies ; Skull Base ; Tertiary Care Centers ; Velopharyngeal Insufficiency

Basilar invagination or basilar impression involves the upward displacement of the margins of the foramen magnum into the base of the skull. That this entity may be asymptomatic or associated with symptoms referable to encroachment into the posterior fossa or embarrassment of the posterior circulation is well known. Currently the authors have experienced a young male patient with basilar invagination presented with progressive myelopathy and lower cranial neuropathies due to odontoid invagination. It was thought that a posterior decompression would be hazardous;therefore, the inferior clivus, odontoid process, and anterior arch of the atlas were removed transoral-transpharyngeally and bone fusion was performed with iliac bone. Furthermore the operative result was good without any serious complication. The operation technique is detailed.
Cranial Fossa, Posterior ; Cranial Nerve Diseases ; Decompression ; Foramen Magnum ; Humans ; Male ; Odontoid Process ; Platybasia ; Skull ; Spinal Cord Diseases

OBJECTIVE: In this study, we aimed to investigate the underlying ethiological factors in chiari malformation (CM) type-I (CMI) via performing volumetric and morphometric length-angle measurements. METHODS: A total of 66 individuals [33 patients (20-65 years) with CMI and 33 control subjects] were included in this study. In sagittal MR images, tonsillar herniation length and concurrent anomalies were evaluated. Supratentorial, infratentorial, and total intracranial volumes were measured using Cavalieri method. Various cranial distances and angles were used to evaluate the platybasia and posterior cranial fossa (PCF) development. RESULTS: Tonsillar herniation length was measured 9.09+/-3.39 mm below foramen magnum in CM group. Tonsillar herniation/concurrent syringomyelia, concavity/defect of clivus, herniation of bulbus and fourth ventricle, basilar invagination and craniovertebral junction abnormality rates were 30.3, 27, 18, 2, 3, and 3 percent, respectively. Absence of cisterna magna was encountered in 87.9% of the patients. Total, IT and ST volumes and distance between Chamberlain line and tip of dens axis, Klaus index, clivus length, distance between internal occipital protuberance and opisthion were significantly decreased in patient group. Also in patient group, it was found that Welcher basal angle/Boogard angle increased and tentorial slope angle decreased. CONCLUSION: Mean cranial volume and length-angle measurement values significantly decreased and there was a congenital abnormality association in nearly 81.5 percent of the CM cases. As a result, it was concluded that CM ethiology can be attributed to multifactorial causes. Moreover, congenital defects can also give rise to this condition.
Cisterna Magna ; Congenital Abnormalities ; Cranial Fossa, Posterior ; Encephalocele ; Foramen Magnum ; Fourth Ventricle ; Humans ; Magnetic Resonance Imaging* ; Odontoid Process ; Platybasia ; Syringomyelia

Objective: To examine the effect of posterior atlanto-axial intraarticular distraction technique as revision surgery for failed posterior fossa decompression in patients with basilar invagination(BI) and atlanto-axial dislocation(AAD). Methods: The clinical data of 13 cases of AAD accompanied with BI treated at Department of Neurosurgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. There were 3 males and 10 females,aged (42.6±9.5) years (range:30 to 63 years). All cases had assimilation of atlas and once underwent posterior fossa decompression. Anterior tissue was released through posterior approach followed by cage implantation into facet joint and occipital-cervical fixation with cantilever technique. The clinical results were evaluated using Japanese Orthopedic Association scale(JOA) and the main radiological measurements including atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line(DCL),clivus-canal angle(CCA) and the length of syrinx were collected. Paired sample t test was used to compared the data before and after operation. Results: All patients underwent surgery successfully, the mean surgical time was (187.7±47.4) minutes (range from 116 to 261 minutes). Twenty occipital condyle screws, 26 C2 pedicle screws and 3 occipital plates were implanted. Clinical symptoms improved in all patients. Twelve patients had complete reduction of basilar invagination and atlanto-axial dislocation, 1 achieved near completely reduction of basilar invagination. The postoperative ADI, DCL and CCA significantly improved((4.3±1.1) mm vs. (1.8±0.8) mm, (11.7±5.0) mm vs. (6.4±2.8) mm, (142.4±7.9)° vs. (133.3±7.9)°, all P<0.01).There were 5 cases with syringomyelia before surgery, and shrinkage of syrinx was observed 1 week after surgery in all cases. Eight patients achieved bone fusion 3 months after surgery, all patients achieved bone fusion 6 months after surgery. The JOA score increased from 12.8±2.3 before surgery to 14.8±1.3 one year after surgery, with statistically significant difference (t=4.416, P<0.01).No implant failure, spacer subsidence and infection were observed. Conclusion: In cases of failure posterior fossa decompression of basilar invagination and atlanto-axial dislocation, using posterior atlanto-axial intraarticular distraction and cantilever technique with cage implantation could achieve complete reduction and symptomatic relief.
Atlanto-Axial Joint/surgery* ; Female ; Humans ; Joint Dislocations/surgery* ; Male ; Pedicle Screws ; Platybasia/surgery* ; Reoperation ; Retrospective Studies ; Spinal Fusion/methods*

BACKGROUND: The outcome of spontaneous intracranial hypotension (SIH) is unpredictable and some patients have persistent and often incapacitating symptoms. This study was aimed to investigate whether abnormalities on initial magnetic resonance imaging (MRI) can predict the outcome in patients with SIH. METHODS: We retrospectively included 44 patients with SIH. Brain MRI was available for all patients. Treatment consisted of conservative treatment and/or high-volume epidural blood patching. Patients were divided into two groups: favorable or non-favorable group. Favorable group was defined as clinical improvement by conservative therapy or one trial of autologous epidural blood patching; non-favorable group as more than two week of admission, two or more trials of autologous epidural blood patching, or relapse of orthostatic headache. RESULTS: Twenty-one (48%) of 44 patients were classified as the favorable group. The non-favorable group had several abnormal findings on brain MRI (16 cases vs. 5 cases in favorable group, p<0.003), including platybasia (1), skull base tumor (1), Chiari I malformation (1), diffuse mild thickening and enhancement of dural and epidural layer of thoracic spine (1), pituitary enlargement (3), sagging brain (3) and subdural hemorrhage (4). In the non-favorable group, 13 out of 23 patients (57%) showed pachymeningeal enhancement in brain MRI (2 patients in favorable group, p<0.001). CONCLUSIONS: Brain MRI abnormalities were more frequently related with non-favorable outcomes in SIH. Pachymeningeal enhancement in particular could suggest an unfortunate prognosis.
Blood Patch, Epidural ; Brain* ; Headache ; Hematoma, Subdural ; Humans ; Intracranial Hypotension* ; Magnetic Resonance Imaging* ; Platybasia ; Prognosis* ; Recurrence ; Retrospective Studies ; Skull Base ; Spine

We report a case of Klippel-Feil syndrome. The patient was a 37-year-old man who developed progressive motor weakness and on C4-5 and C6-7 segments combined with severe cervical stenosis, basilar impression and C1 assimilation. He showed progressive quadriparesis and respiratory difficulty. He had combined congenital anomaly of right side facial palsy of peripheral type and right side sensorineural hearing loss. In May 2002, we performed, via transoral approach, anterior fusion with Harm's mesh and hydroxyapatite from the clivus to the C3. But, one month after the operation, Harm's mesh with hydroxyapatite slipped anteriorly due to non-union. So, we removed the mesh and reoperated with fibular bone graft from the clivus to the C3. Simultaneously, posterior approach was performed with on-lay autologous rib bone graft and wiring from the occiput to the C2, 3, 4. One year after the operation, his motor weakness has been gradually improved and there is minimal difficulty in self-respiration.
Adult ; Constriction, Pathologic ; Cranial Fossa, Posterior ; Durapatite ; Facial Paralysis ; Hearing Loss, Sensorineural ; Humans ; Klippel-Feil Syndrome* ; Platybasia ; Quadriplegia ; Ribs ; Spondylosis* ; Transplants

OBJECTIVETo investigate the surgical outcome and its influencing factors in patients of congenital basilar invagination (BI) with atlanto-axial dislocation (AAD).

METHODSFrom May 2004 to August 2010, 120 patients who had BI with AAD were surgically treated with direct posterior intraoperative distraction-reduction and fixation technique, 93 patients were successfully followed up by means of questionnaire survey, telephone and clinical evaluation. Pre- and postoperative dynamic cervical X-rays, computed tomographic scans, 3-dimentional reconstruction views and magnetic resonance imaging were performed. Pre- and postoperative Japanese Orthopaedic Association (JOA) score, distance between odontoid tip and Chamberlain's line and atlantodental interval were measured to evaluate the surgical result. Statistical analysis was performed by means of paired t test and Pearson Correlation analysis.

RESULTSThere were 93 cases were followed up for 24-99 months with an average of 46.5 months. Until the final follow-up, clinical symptoms were improved in 79 patients (84.9%), and were stable in 7 patients (7.5%) and deteriorated in 4 patients (4.3%). Three patients died postoperatively (3.2%). Patients without intramedullary signal intensity change (ISIC) had better surgical outcome. Patients with compression from anterior odontoid tip and posterior bone margin of occipital foramen had the worst surgical outcome (F = 3.987, P < 0.01). Overall, good decompression and bone fusion were shown on postoperative image in 87 patients (93.5%). There were 3 deaths in this series because of basilar artery thrombosis, posterior fossa hematoma and unknown reasons each.

CONCLUSIONSThe direct posterior intraoperative distraction-reduction and fixation technique is an effective simple and safe method for the treatment of BI with AAD. Anterior compression from odontoid tip and posterior compression from bone margin of occipital foramen-atlantal posterior arch play important roles in its developing mechanism. ISIC on MRI is a predictive factor for the worse surgical outcome.

Adolescent ; Adult ; Atlanto-Axial Joint ; surgery ; Bone Screws ; Child ; Decompression, Surgical ; Female ; Follow-Up Studies ; Humans ; Joint Dislocations ; complications ; surgery ; Male ; Middle Aged ; Platybasia ; complications ; surgery ; Root Cause Analysis ; Spinal Fusion ; methods ; Young Adult