Intraventricular meningiomas: a surgical challenge.

BACKGROUND: Primary intraventricular meningiomas (IVM) pose a surgical challenge as they often remain asymptomatic until they become very large; have close proximity to vital intraventricular structures; and, their vascular supply is often encountered only after significant tumor debulking. In this study, the surgical management of IVM is discussed. METHODS: Between 1989 and 2003, nine patients (7 with lateral and 2 with fourth ventricular) IVM, were operated upon. Raised intracranial pressure, gait ataxia, memory impairment, seizures (motor and sensory) were the main presentations. Four had hydrocephalus while five had either a sequestered temporal or occipital horn. All were large tumors with an average size more than 5.3 cm. The lateral ventricular IVM were accessed by the posterior middle temporal gyrus (n=5) or the superior parietal lobule (n=2) approach. A midline suboccipital craniectomy was used for the fourth ventricular IVM. RESULTS: Total excision was achieved in eight and partial excision in one. Patients with lateral ventricular tumors required a postoperative intraventricular drain for a minimum period of 48 hours. The main morbidity included visual field defects and transient hemiparesis, seizure and meningitis. The one patient with partial excision died 6 weeks later due to transtentorial herniation as a result of intratumoral bleed and lateral ventricular sequestration. CONCLUSIONS: An IVM, being initially asymptomatic, usually attains a large size before detection. During surgery, its devascularisation is usually achieved only after significant tumor debulking. Development of hydrocephalus or ventricular sequestration should be constantly monitored and may be avoided in the postoperative period by continuous external ventricular drainage.

Surgery of vestibular schwannomas: an institutional experience.

AIMS: To report management results of vestibular schwannomas (VS) treated surgically in our institute, with particular reference to completeness of tumor excision, facial nerve and hearing preservation and complications of surgery. STUDY DESIGN AND SETTINGS: Retrospective study of 259 patients treated during the years 1988 to 2002. MATERIALS AND METHODS: The facial nerve function and hearing assessment was done according to House-Brackmann [HB] grading and pure tone audiometry (PTA) respectively. All patients were operated by retro-mastoid sub-occipital approach. RESULTS: Most patients had large tumors and had no useful hearing (90%), had disabling cerebellar ataxia (88%) and presented with features of raised intra-cranial pressure (45%). Large sized tumors were in 41.3% and giant sized tumors were in 56% cases. Complete tumor excision was carried out in 96.5% and anatomical preservation of facial nerve was achieved in 79.2% cases. Hearing preservation was achieved in 8 patients. Cerebrospinal fluid leak with or without meningitis and transient lower cranial nerve paresis were common complications. The mortality was 6%. CONCLUSIONS: With experience, complete tumor excision with good facial nerve preservation can be achieved in large tumors. Hearing preservation is difficult in bigger tumors. Prevention and control of infection was a major concern.

Surgical management of remote, isolated type II odontoid fractures with atlantoaxial dislocation causing cervical compressive myelopathy.

OBJECTIVE: The remote (more than 6 mo after injury) and isolated (not associated with any other cervical spinal fractures) Type II fractures of the odontoid (RI IIO) are unique in being inherently unstable and prone to malunion or nonunion, leading to cervical compressive myelopathy. The present study discusses their surgical management. METHODS: Nineteen patients with RI IIO with atlantoaxial dislocation (AAD) causing compressive myelopathy were treated. Their preoperative disability was graded as Grade I: neurologically intact (presented with hyperreflexia and mild spasticity; n = 3); Grade II: independent with minor disability (n = 7); Grade III: partially dependent for daily needs (n = 6); and Grade IV: totally dependent (n = 3). They were classified as irreducible AAD caused by 1) malunited fracture of the odontoid (n = 2), 2) fixed anterolisthesis of the anterior arch of a C1-fractured odontoid complex (n = 3), and 3) fixed retrolisthesis of the anterior arch of a C1-fractured odontoid complex (n = 1); and reducible AAD caused by 1) mobile AAD (n = 11) and 2) hypermobile AAD (n = 2). The patients with irreducible AAD underwent a transoral decompression and posterior fusion; those with a malunited fracture underwent surgery immediately, whereas those with fixed anterolisthesis or retrolisthesis were initially placed in cervical traction. The patients with reducible AAD underwent a direct posterior fusion. In the patient with "hypermobile" AAD, a proper alignment of the fractured segment of the odontoid relative to the body of the axis in a neutral position of the neck was ensured before the posterior fusion was performed. RESULTS: At follow-up (mean, 15.37 +/- 9.67 mo), three patients in Grade I maintained their neurological status. Of the seven patients in Grade II and six in Grade III, five had improved to Grade I, and eight were in Grade II. The three patients in Grade IV improved to Grade I, II, and III, respectively. CONCLUSION: The patients with RI IIO may be divided into five groups on the basis of their differing management protocols. There is a considerable risk of delayed myelopathy unless surgical reduction and stabilization are performed. Posterior stabilization is the preferred option in dealing with these fractures. Despite the presence of severe neurological deficits and the prolonged duration of symptoms, a significant neurological improvement usually occurs after surgery.

Solitary Langerhans-cell histiocytosis of the clivus and sphenoid sinus with parasellar and petrous extensions: case report and a review of literature.

BACKGROUND: In Langerhans-cell histiocytosis, there occurs an uncontrolled clonal proliferation of dendritic cells that have Langerhans cell like characteristics. In this report, a unique case of a solitary, skull base Langerhans-cell histiocytosis (LCH) is described. CASE DESCRIPTION: A 15-year-old boy presented with raised intracranial pressure, decreased visual acuity, bilateral abducent nerve palsy, and 25% hypoesthesia in all three divisions of the right trigeminal nerve. He had normal strength but with a left-sided upper and lower limb hypertonia and hyper-reflexia and an upgoing plantar reflex. The magnetic resonance (MR) imaging revealed a heterogeneously iso-to hyperintense lesion of the clivus and the sphenoid sinus, extending to the right cavernous sinus to encase the right cavernous internal carotid artery segment, and also involving the right petrous apex and the extradural space in the prepontine region. The lesion was brilliantly enhancing on contrast. An extended frontobasal approach was used to excise the lesion. Following surgery, the residual parasellar and the right petrous apex tumor was treated with a low dose radiation therapy. At follow-up after 1.5 years, there was significant clinical improvement and the computed tomographic scan showed no residual lesion. CONCLUSION: A review of the literature reveals that this is only the second reported case of a spheno-clival LCH. An additional feature includes extensions into the parasellar as well as the petrous apex regions. Despite the extensive spread, the surgical excision with low dose radiation therapy was successful in providing complete resolution of the tumor.

Surgical approach to C1-C2 nerve sheath tumors.

BACKGROUND: C1 and C2 nerve sheath tumors (NST) are unique in presentation, relationship to neighbouring structures and surgical approaches when compared to their counterparts in other regions of the spine. AIM: The strategies involved in the surgery for C1-C2 NST are discussed SETTING AND DESIGN: Retrospective study. METHODS: 21 patients with C1 (n=6) and C2 (n=15) NST were operated based on their position with respect to the cord i.e. anterior (4), anterolateral (10), posterolateral (5), and posterior (2). The tumors had extra- and intradural components in 20 patients; while in one, the tumor was purely intradural. The operative approaches included the extreme lateral transcondylar approach (3); laminectomy with partial facetectomy (5); laminectomy (11); and, suboccipital craniectomy and laminectomy (2). RESULTS: Total excision was performed in 13 patients; while in 7, a partial extraspinal component, and in 1, a small intradural component were left, in situ. Thirteen patients showed improvement by one or more grades in the Harsh myelopathy score; 2 patients with normal power had significant decrease in spasticity; while 5 maintained their grade. One poor-grade patient succumbed to septicemia. CONCLUSIONS: C1-C2 NST may have exuberant growth due to the capacious spinal canal and the absence of a "true" intervertebral foramen at this level. Surgical approaches are determined by its relationship to the cord. A "T incision" on the dura, the partial drilling of the facets, sectioning of the denticulate ligament, rotating the operating table 15 to 30 degrees, and at times sectioning the posterior nerve roots are all useful adjuncts for facilitating access.

Factors influencing the outcome in symptomatic Chiari I malformation.

BACKGROUND: To study the clinico-radiological determinants of outcome in patients with Chiari I malformation (CIM). MATERIALS AND METHODS: The disability assessment of 48 patients with C I M who underwent posterior decompression was done by modified Klekamp and Samii scoring system. The outcome was regarded as good when the patient was ambulant without any aid with an improvement in the disability score; and, poor when (a) there was postoperative deterioration or lack of improvement; (b) the patient was non-ambulant without aid, irrespective of the improvement in the clinical score; or, (c) there was a perioperative mortality. Patients with hydrocephalus; those who underwent syringo-subarachnoid or syringo-peritoneal shunt as the primary procedure; and, patients with atlanto-axial dislocation were excluded from the study. STATISTICAL METHODS USED: Categorical data were expressed in proportions and analyzed with Chi square test. Analysis of factors predicting clinical outcome at 6 months was done utilizing logistic regression analysis. RESULTS: The outcome assessed at six months showed that 30 patients (62.5%) had good outcome while 18 patients (37.5%; including two perioperative mortalities) had a poor outcome. CONCLUSIONS: Significant predictors of outcome in patients with CIM include the duration of symptoms (P value=0.006), respiratory distress (P value=0.001), and basilar invagination (P value=0.048). The effect of syringomyelia in predicting the clinical outcome could not be determined due to the differences in the number of patients in the groups with or without syringomyelia.

Atlantoaxial dislocation associated with the maldevelopment of the posterior neural arch of axis causing compressive myelopathy.

The craniovertebral junction has a predilection for a variety of congenital anomalies due to its complex development. The association of atlantoaxial dislocation (AAD) with the maldevelopment of the posterior arch of axis is extremely rare. We report two such cases and present the management strategy.

Intrinsic third ventricular craniopharyngiomas: report on six cases and a review of the literature.

BACKGROUND: Craniopharyngiomas constitute 2 to 4% of intracranial neoplasms. However, the purely intraventricular variety are rare. Their magnetic resonance imaging (MRI) characteristically shows an intact third ventricular floor, a patent suprasellar cistern, an intact pituitary stalk, and the absence of sellar abnormalities. METHODS: Between 1994 and June 2002, 6 patients with purely intraventricular craniopharyngioma were surgically managed. There were 4 cystic and 2 solid lesions. The surgical approaches utilized included a frontal, parasagittal, transcallosal approach with the third ventricle being accessed using either the transforaminal or subchoroidal approach (n = 3); pterional, transsylvian (n = 1), and bifrontal interhemispheric (n = 2) approaches in which the third ventricle was accessed via the lamina terminalis. A ventriculoperitoneal shunt was required for one of the 3 patients with hydrocephalus. RESULTS: Total excision was performed in 3 patients with cystic craniopharyngioma, while a small residual lesion was left adherent to the third ventricular floor in the others. There was one perioperative mortality because of septicemia. Two patients required thyroxine supplementation. Two patients developed transient and one other patient a sustained diabetes insipidus. The 2 patients with solid tumors received radiotherapy for the residual lesions. At follow up ranging from 8 to 36 months, neither tumor recurrence nor regrowth was observed in any of the patients. The symptoms of raised intracranial pressure, hypothalamic dysfunction or visual field defects had resolved. CONCLUSIONS: Intraventricular craniopharyngiomas occur in an older population and present mainly with raised intracranial pressure. Visual and endocrinologic imbalances are much less in these lesions compared to the suprasellar craniopharyngiomas. They mainly attach to the third ventricular floor. The surgical approaches to the third ventricle, along with radiotherapy and hormone supplementation, were successful in the management of these rare tumors.

Craniocervical tuberculosis: protocol of surgical management.

OBJECTIVE: Craniovertebral junction tuberculosis (CVJ-TB) is rare and occurs in only 0.3 to 1% of patients with tuberculous spondylitis. In the available literature, the treatment options offered for this entity have ranged from a purely conservative approach to radical surgery without well-defined guidelines. In this study, we attempt to establish the most effective strategy for the management of this condition. METHODS: Twenty-five patients with CVJ-TB were treated during the past 8 years. Severe neck pain, restricted neck movement, and myelopathy were the predominant symptoms. The patients were graded according to their disability as follows: Grade I (n = 7), only neck pain with no pyramidal tract involvement; Grade II (n = 8), independent with minor disability; Grade III (n = 1), partially dependent on others for assistance with activities of daily living; and Grade IV (n = 9), completely dependent on others for assistance with all activities of daily living. Nine patients in Grade IV also had severe respiratory compromise. In all patients, lateral radiographs of the CVJ in flexion and extension were used to determine the presence of atlantoaxial dislocation (AAD). Bony destruction, paraspinal abscess, and thecal compression were seen on intrathecal contrast computed tomographic scans (n = 9) and magnetic resonance imaging studies (n = 22). Under the cover of antituberculous therapy (ATT) administered for 18 months, the patients were placed under a management protocol that took into account the patient's preoperative grade, the presence of mobile or fixed AAD, bony destruction and retropharyngeal abscess formation at the CVJ, and the clinicoradiological response to ATT within 3 months. Thus, 14 patients were kept on conservative management, with their neck movements stabilized with an external orthosis; 4 patients underwent a single-stage transoral decompression and posterior fusion procedure; and 7 patients underwent direct posterior fusion. RESULTS: In a follow-up period that ranged from 6 months to 7 years (mean, 2.5 yr), the patients in Grades I and II maintained their neurological status. The single patient in Grade III improved to Grade II. Seven of the nine patients in Grade IV returned to normal, and one improved to Grade II. Neck pain improved in all patients. The only death in the series occurred as a result of aspiration pneumonitis leading to septicemia in a child in Grade IV with poor respiratory status and multilevel tuberculous involvement who had undergone transoral decompression and posterior fusion for fixed AAD. CONCLUSION: This study discusses the clinicoradiological presentation as well as the management of CVJ-TB, in which ATT is administered for 18 months. In the patients with minor deficits (Grades I and II), conservative neck stabilization is adopted; in the patients with severe deficits (Grades III and IV) due to significant cervicomedullary compression caused by fixed AAD or bone destruction and granulation, anterior decompression and posterior fusion are performed. Patients with persistent reducible AAD undergo direct posterior fusion. A significant improvement is possible even in poor-grade patients with judicious use of the surgical options and ATT.