'Atlas shrugged': congenital lateral angular irreducible atlantoaxial dislocation: a case series of complex variant and its management.

PURPOSE: The commonly described congenital atlanto-axial dislocation and Basilar-Invagination is antero-posterior or rotational or vertical plane. However, congenital dislocation in lateral plane has received scant attention. The purpose of this manuscript is to describe this unusual entity and discuss its management. MATERIALS AND METHODS: The clinic-radiological feature of seven patients with congenital lateral angular AAD (CLAAAD) were studied and managed. The unilateral C1 facet had subluxed lateral to C2-3 complex. The C1 and C2 facets were drilled comprehensively and repositioned with distraction, placement of metallic spacers and facet manipulation after insertion of screws. The post operative outcome was studied. RESULTS: The presentation is usually with neck tilt (progressive in 3) and/or progressive spastic quadriparesis. The mean C1-2 tilt was 25.2°. C1 was bifid in six patients. C1 lateral mass was assimilated with occipital condyle on dislocated side in and the other side was normal (6 patients). The dislocated C1-2 joint was abnormally oblique as compared to contralateral side. The relationship of occiput and C1 was normal. Correction of dislocation and lateral tilt was achieved in all patients with subsequent correction of neck tilt and deficits. One patient required reoperation. CONCLUSIONS: The acute angulation of joint on one side and near normal on other side leads to differential vertical movement, further accentuated by splaying of bifid C1. The entity is seen in young patients and often present with neck tilt and spastic quadriparesis. Management requires reshaping the joints and facet manipulation. If the reshaping is inappropriate, the joint is likely to redislocate before fusion occurs.

'Pseudofacets' or 'supernumerary facets' in congenital atlanto-axial dislocation: boon or bane?

PURPOSE: Certain abnormal contact points, appearing like additional joints (pseudofacets) were observed between atlas and axis in a subset of patients with congenital atlantoaxial dislocation (CAAD). The origin, function and bearing on management of such pseudofacets remain largely undetermined. The object is to study 'pseudofacets'or 'accessory joints' in patients with CAAD and to analyze the possible genesis, role and bearing of these on surgery and fusion rates. MATERIALS AND METHODS: 35 patients with CAAD were analyzed. Reconstructed images of CT craniovertebral junction passing through these pseudo and true facets were studied. A novel method was devised to measure the faceto-isthmic angle of axis, both in patients with CAAD and normal subjects. Operative details and fusion rates were studied in patients with pseudofacets and compared with those without it. RESULTS: Eight out of 35 patients (6 Irreducible CAAD and 2 with RCAAD) had pseudofacets. These are seen posterior to the true facets and resemble partially formed joints. The C2 facet was acutely bent over its isthmus in these patients. The direction of these pseudofacets appeared to counter the abnormal mobility at C1-2 true facets. Intraoperatively, they posed a visual hindrance to reach up to true facets for placement of spacers and lateral mass screws, requiring extensive drilling. At the same time, they did help in distraction and increased the surface for fusion between C1 and C2 in cases where sublaminar wiring alone was used. Fusion rates were 100 % in patients with pseudofacets. CONCLUSIONS: Pseudofacets may be a result of genetic aberration and nature's mechanism to restrict abnormal C1-2 mobility in CAAD by imparting some stability. Their presence hinders the visualization making it difficult to reach upto the true facets, thus a bane. They may require extensive drilling when direct posterior approach is used, thereby disrupting the natural restrictive mechanism. However, the flattened surfaces provide an increased area for postoperative bony fusion between C1 and 2, making their presence a 'boon'.

Factors influencing feasibility of direct posterior reduction in irreducible traumatic atlantoaxial dislocation secondary to isolated odontoid fracture.

INTRODUCTION: Direct posterior reduction by intraoperative manipulation of joints for irreducible traumatic atlantoaxial dislocation (IrTAAD) has gained acceptance in the recent past. However, factors determining its feasibility have not been elucidated. Our study aims to examine the clinico-radiological factors predicting feasibility of direct posterior reduction in IrTAAD secondary to isolated odontoid fracture, in an attempt to differentiate the "truly irreducible" from those "deemed irreducible." MATERIALS AND METHODS: The onset and progression of neck pain and myelopathy was studied in 6 patients of IrTAAD with fracture odontoid, which failed to reduce despite traction. The dynamic X-rays and computed tomography (CT) scans of craniovertebral junction, along with the vertebral artery angiogram were studied to look for the slightest mobility, interface of fractured fragments, malunion, callous, and relationship of the C1-2 facets and vertebral artery. RESULTS: All 6 patients had progressive worsening of neck pain. Three patients had progressive myelopathy. Three patients presented 6 months after trauma. Radiology showed type-II fracture with IrTAAD (anterolisthesis in 5 and retrolisthesis with lateral dislocation in 1) and locked facets in all. X-rays showed doubtful callous formation in 3 patients and CT confirmed non-union. Three patients showed angular movement on dynamic X-rays despite irreducibility and locked facets. Angiogram showed thrombosis of vertebral artery in one patient. Intraoperative reduction could be achieved in all 6 patients with good clinico-radiological outcome. CONCLUSION: Worsening pain, progression of myelopathy, some movement on dynamic X-rays, a malunion ruled out on CT scan, and the presence of locked facets make direct posterior reduction feasible in patients with IrTAAD. The difficulty increases in remote fractures due to fibrosis around the dislocated joints. The role of the CT angiogram, in defining the relationship of Vertebral artery (VA) to the dislocated facets, and in determining the extent of VA injury, is vital. Preoperative detection of VA injury reduces the chance of intraoperative reduction, especially if only unilateral joint approach is planned.

Ventral compression in adult patients with Chiari 1 malformation sans basilar invagination: cause and management.

BACKGROUND: A small subset of patients with adult Chiari I malformation without basilar invagination (BI) and instability show ventral cervicomedullary distortion/compression and have symptoms pertaining to that. The cause of this ventral compression remains speculative. Additionally, it is unclear if these patients would require ventral decompression with posterior fusion or only posterior decompression would suffice. METHODS: Sixteen adult patients with Chiari I malformation with significant ventral cervicomedullary compression, in the absence of BI, were included in the study. Atlantoaxial dislocation (AAD) was excluded in these patients by flexion-extension craniovertebral junction X-rays and computed tomography (CT). Their clinical profile, especially symptoms pertaining to cervicomedullary compression, i.e. dysphagia, dysarthria and spasticity, were graded. The ventral cervicomedullary compression (VCMC) was quantified using pBC2 (maximum perpendicular distance to the basion-infero posterior point of the C2 body) on sagittal magnetic resonance imaging (MRI) and only those patients with pBC2 ≥9 mm were included. Furthermore, retroversion of dens and retro odonotid tissue thickness was calculated in each patient. Fifteen patients underwent posterior decompression alone and one refused surgery. Follow-up was done every 3 months. Repeat MRI was done at 1 year following surgery to look for pBC2. RESULTS: The mean pBC2 was 11 ± 0.2 mm. Retroversion of dens was responsible for VCMC in three patients and periodontoid crown in 13. There was no correlation between the tonsillar descent, age and the pBC2. All patients improved in symptoms of cervicomedullary compression following surgery. One patient worsened 6 months after initial improvement. The pBC2 did not change, as seen on follow-up MRI done in five patients. CONCLUSIONS: VCMC in adult patients with Chiari I malformation in the absence of BI and/or AAD is due to periodontoid tissue (crown) or retroverted dens. Though a long-term study is required, it appears that all patients with Chiari I malformation, irrespective of the VCMC, can be given a chance with posterior decompression alone. Transoral decompression with posterior fusion may be required in a small subset of patients who fail to improve or worsen following posterior decompression only.

An exophytic brain stem glioblastoma in an elderly presenting as a cerebellopontine angle syndrome.

Exophytic brain stem gliomas are rare and are generally seen in paediatric population. These are usually low grade gliomas. We report a case of brainstem glioblastoma in an elderly patient presenting as a cerebellopontine mass.

Primary intraosseus cavernous hemangioma of the skull base.

Primary intraosseous cavernous hemangioma (PICH) of the skull is rare. We present a case of 11-year-old boy with PICH of the sphenoid bone. The Computed Tomogram showed a classical sunburst appearance. Safe excision as much as possible was attempted after embolization. The child however, succumbed to postoperative infection. The preferred treatment is complete tumor removal with normal bony margins. However, this may not be possible in extensive skull base involvement. Preoperative embolisation can reduce intraoperative blood loss. Radiotherapy may be added where complete excision is not possible.

Mirror-like aneurysms of proximal anterior cerebral artery: report of a case and review of literature.

'Mirror-like' or 'twin' aneurysms, which are located bilaterally on corresponding arteries, constitute less than 5% of overall aneurysms and mirror aneurysms on proximal anterior cerebral artery (A1) have never been reported in the past. We report a case of bilateral proximal A1 segment aneurysms (mirror). The approach to this patient is being described and the literature reviewed. The proximal A1 segment aneurysm is more approachable from the contralateral side. In case of mirror A1 aneurysms, the approach may be better from contralateral side of the larger aneurysm.

Sudden-onset ptosis caused by midbrain neurocysticercosis in 2 children.

Neurocysticercosis is the most common parasitic infestation of the central nervous system, which manifests commonly as acute-onset focal seizures. We report a rare nonepileptic manifestation of neurocysticercosis: midbrain neurocysticercosis presenting as sudden-onset ptosis in 2 children. To our knowledge, this has not been reported previously in children.

Long-term Cognitive Outcome of Children With Parenchymal Neurocysticercosis: A Prospective Observation Study.

To study the cognitive profile and scholastic performance of children with parenchymal neurocysticercosis. A total of 500 children with a diagnosis of neurocysticercosis and epilepsy registered in our pediatric neurocysticercosis clinic between January 1996 and December 2002 were enrolled. Patients were evaluated for their scholastic performance using their school grades. Cognitive assessment was done using Parental interview and the "Draw-a-Man" test. Poor scholastic performance was seen in 22.2% (111) children. Draw-a-Man test was done in 148 children; 18.2% (27/148) had scores equivalent to IQ <70. Intermittent headache, behavior problems, and poor memory were reported in 40% (201) children. Multiple lesions, lower socioeconomic status, and calcified lesions on follow-up were associated with academic underachievement ( P < .05). About a fourth of children with neurocysticercosis had cognitive impairment during follow-up. This was mostly seen in children from lower socioeconomic status and in those with multiple-lesion neurocysticercosis.

Evaluation of anterior third of superior sagittal sinus in normal population: Identifying the subgroup with dominant drainage.

BACKGROUND/OBJECT: The ligation and transection of anterior third of superior sagittal sinus (AT-SSS) is an important step to approach anterior skull base lesions. Some clinical studies have shown frontal lobe venous infarct following such surgical procedures questioning the safety of its ligation. We have studied the variations in venous drainage patterns to AT-SSS in the normal population using postcontrast magnetic resonance venogram (MRV). A novel scoring system to recognize the subgroup with dominant venous drainage from frontal lobes has been described. MATERIALS AND METHODS: In this study, 60 three-dimensional contrast-enhanced (CE) MRVs were obtained from those cases being evaluated for a headache not harboring any intracranial mass lesion. The AT-SSS with all its draining veins was studied in detail. Morphology of individual veins such as length, caliber, tributaries, and angulation with AT-SSS was studied, and a numerical value of 0 or 1 was assigned for each of the above parameters. Summing up these scores derived from the individual cortical veins quantified the drainage of AT-SSS. RESULTS: There are 3-4 veins on either side draining to AT-SSS. Barely, 3% of the veins had > 3 tributaries. Only 6.6% of veins had a caliber >3 mm, and 16.5% drained at acute angles to AT-SSS. About 26% of the veins did cross at least half of the lateral frontal lobe. We found in 26 individuals the AT-SSS score was 0-2, in 22 it was 3-5 and, in only in 12 (20%) the score was 6 or more (dominant drainage). CONCLUSION: There are anatomical variations in venous drainage of frontal lobes into AT-SSS. Those with dominant drainage are likely to develop venous congestion and complications if sacrificed. It is possible to identify these individuals on the basis of venous drainage pattern as shown in CE-MRV.

Technique for direct posterior reduction in irreducible atlantoaxial dislocation: multi-planar realignment of C1-2.

OBJECTIVE: Apart from the commonly seen antero-posterior subluxation of C1 over C2, the dislocation may occur in vertical, lateral or rotational plane. Desired C1-2 realignment can be achieved by corrrecting its dislocation in all planes. We describe a technique for the same. MATERIAL AND METHODS: The clinical and radiological features of 16 patients (4 ­ traumatic and 12 ­ congenital) with irreducible atlantoaxial dislocation (AAD) admitted in the last 1.5 years were studied. Specific attention was paid to vertical dislocation with lateral and rotational components, apart from anterior-posterior subluxation. They were operated through direct posterior approach. The technique using a long rod holder as lever and screw head (tulip) as fulcrum was employed to achieve C1-2 realignment in all planes. The postoperative clinical and radiological data was analyzed and compared with preoperative data. RESULTS: Patients presented with progressive myelopathy and/or progressive worsening of neck pain. Vertical dislocation was seen in 11 patients with congenital AAD in addition to the antero-posterior subluxation seen in all. Three patients with traumatic AAD and 8 with congenital AAD had additional lateral dislocation or lateral tilt. Three patients with traumatic AAD and 7 with congenital AAD showed rotational component. Postoperatively, all patients showed clinical improvement. CONCLUSIONS: The antero-posterior and vertical realignment could be achieved in all except one. Similarly, rotational and lateral components could be completely corrected in 8 out of 10 patients. The technique appears to realign the C1-2 in all planes and provides good anatomical restoration.

Brain metastasis from urachal carcinoma: case report.

A rare case of metastasis to the brain from an urachal carcinoma is reported. Metastasis in the brain developed 7 months after partial cystectomy and radiation therapy. Cranial computed tomography showed a ring-enhancing mass lesion that was excised. A month later, the patient died of distant metastasis.

Aggressiveness of pediatric cholesteatoma. Do we have an evidence?

To compare pediatric and adult patients, affected by cholesteatoma for the clinical presentation, disease extent and final outcome. This is a prospective study in which 60 cases of unsafe chronic suppurative otitis media with cholesteatoma were included. These cases were divided into two groups of 30 cases each on the basis of age. All patients were subjected to detailed clinical examination. A high resolution computed tomography of the temporal bone was done in all the cases. An innovative grading system was devised to grade the disease. The patients were subjected to canal wall down mastoidectomy and were evaluated postoperatively for resolution of the symptoms, hearing and cavity problems. Granulation tissue along with cholesteatoma was more common among children (p < 0.01), whereas cholesteatoma alone was more common among adults. There was excellent correlation between the radiological and surgical findings. It was seen that higher the grade of the disease, the greater was the risk of complications and recidivism (p < 0.05). Recidivism was significantly higher in children (p < 0.05) whereas complications were equally common in both the groups. Hearing improvement was equivocal in both groups. Presence of granulation tissue along with cholesteatoma in children causes more aggressive disease with higher recidivism rate.

Stroke following a bicycle injury.

Stroke is not an uncommon problem in children. However, stroke following intraoral trauma is rare. A high index of suspicion of neurological complications following apparently asymptomatic oral trauma helps to identify this peculiar form of childhood stroke.

Primary multiple intracerebral echinococcosis in a young child.

Primary multiple intracerebral echinococcosis is a very rare disorder particularly in children. In this case report we discuss the details of clinical presentation and management in a young child. We also highlight for the first time non-iatrogenic 'water lily' appearance of the lesion on computed tomography of the head.

Congenital sternal cleft.

A cleft of the sternum is a rare congenital anomaly. We present a case of a sternal cleft in a 7-year-old boy. A split iliac bone graft covered with the sternocostal portion of a pectoralis major flap was used to reconstruct the defect.