A.K. Mahapatra

Awake craniotomy versus surgery under general anesthesia for resection of intrinsic lesions of eloquent cortex—A prospective randomised study

OBJECTIVES Complete removal of a brain tumor without inflicting neurological deficits is a desirable end result in neurosurgical practice. Currently no prospective randomized surgical series in the literature exists comparing tumor resection under general versus local anesthesia awake surgery may achieve more aggressive tumor resection and minimize postoperative neurological morbidity. PATIENT AND METHODS We thence conducted a prospective randomized comparative study of results of surgery under awake versus surgery under general anesthesia for intrinsic eloquent area lesions. Fifty-three patients with intrinsic brain tumors in eloquent areas were prospectively randomized (26 patients in awake group and 27 for surgery under general anesthesia). At 3 months follow up, 23% patients in awake group had permanent deficits compared to 14.8% in GA group. RESULTS More than 90% tumor excision was observed in 57% patients in awake group versus 73.7% in GA group. CONCLUSIONS The mean operative time, blood loss was found to be was found to be less in GA group patients than in awake group. Better tumor cytoreduction, neurological improvement was seen in GA group (motor improvement in 35.7%, speech improvement in 62.5%) than in awake group patients (motor improvement in 18.7%, speech improvement in 14.3%).

Intrasellar tuberculoma — an enigmatic pituitary infection: a series of 18 cases

OBJECTIVE Intrasellar tuberculomas are rare and only few case reports have been described in the literature. We report a series of 18 cases of histologically proven intrasellar tuberculomas, which, to the best of our knowledge, is the largest series in the English literature. METHODS A total of 1143 pituitary lesions, between 1984 and June 1999, were operated for various reasons in our institute. Of these, 18 cases were histopathologically proven intrasellar tuberculomas. The clinical profile was reviewed in detail. Radiological data and histopathological slides were also reviewed. RESULTS The age ranged from 8 to 43 years (average 23.6 years) with a female preponderance. The duration of symptoms varied from 15 days to 2 years (average 4 months), the most common symptoms being headache followed by decrease or loss of vision. Five patients had features of pan-hypopituitarism whereas three had raised prolactin (PRL) levels. In six patients, both sella as well as sphenoid sinus were involved. In one patient the lesion was extending from the sella over the clivus. Clinically as well as radiologically, these lesions were mistaken for pituitary adenomas except for one case where tuberculoma was suspected on imaging. In three patients, there was past history of pulmonary tuberculosis, in one patient of tuberculous meningitis, and in one patient, of spondilytis of the spine. In one patient there was cervical lymphadenopathy along with features of acromegaly (also proved by high levels of serum growth hormone) and radiology revealed a pituitary pathology. Microscopic examination of the excised lesion revealed a composite lesion consisting of a pituitary adenoma and tuberculoma, which has not been documented in literature to date. One patient died during the hospital stay. All the other patients were put on antitubercular chemotherapy following surgery and had good outcomes. CONCLUSION Intrasellar tuberculomas are rare. These may be suspected in female patients especially if radiological imaging shows involvement of paranasal sinuses and pituitary fossa along with thickening of pituitary stalk. Simultaneous involvement of clivus may also be an additional feature. The incidence of pituitary tuberculosis is likely to increase with a rise in the incidence of AIDS.

Anterior Encephaloceles: A Study of 92 Cases

Anterior encephalocele is a rare condition, and only a few large series have been published in the literature. Surprisingly, the incidence is much higher in Southeast Asian countries, including some parts of India. While the reported incidence in the West is between 1:35,000 and 1:40,000 live births, it is as high as 1:5,000 live births in Thailand. We present a series comprising 92 cases of anterior encephaloceles treated over a 30-year period (1971–2000). Frontoethmoidal encephaloceles are the commonest type, followed by the nasopharyngeal and orbital type. Among the frontoethmoidal encephaloceles, nasoethmoid is the commonest type, and these patients present with swelling over the bridge of the nose with significant hypertelorism and orbital deformities. The nasopharyngeal type remains occult and presents with nasal obstruction or CSF rhinorrhea. Rarely, the patient may present with meningitis. Since 1978, computed tomography (CT) scans have regularly been performed in our patients. CT scans delineate the skull defect and associated brain anomalies. There was associated hydrocephalus present in 12 patients and agenesis of the corpus callosum in 5 patients. In all patients, one-stage repair of the encephalocele and correction of bony anomalies by appropriate osteotomy was undertaken. Since 1988, in cases of frontoethmoidal encephalocele with significant hypertelorism, medial advancement of the medial half of the orbits on either sides was carried out, instead of a classical Tessier’s operation. Postoperative morbidity included CSF leak in 20 patients, wound infection in 2 and chest infection in 3. There were 3 deaths in our study. The overall cosmetic outcome was good.

Anterior encephaloceles: A series of 103 cases over 32 years

Anterior encephalocele is a rarely reported CNS malformation with a geographical predilection for South-East Asia. The paucity of literature prompted us to analyse our results with hemiorbital advancement and classical Tessiers operation in 103 cases over 32 years (1971-2002). In our series, the frontoethmoidal subtype was the most common (80%), followed by the orbital (8%), transethmoidal (8%), transsellar (3%) and interfrontal types (1%). All patients with classical frontoethmoidal encephalocele had swelling over the nose or inner canthus since birth, with varying degrees of hypertelorism; and those with the nasopharyngeal subtype commonly presented with nasal obstruction and cerebrospinal fluid (CSF) rhinorrhoea. Neurofibromatosis was present in seven patients, all of whom had an orbital encephalocele. The diagnostic workup included a computerised tomography scan of the head in 96 patients and magnetic resonance imaging of the brain in 16 patients. The associated findings on imaging were hydrocephalus (15%), corpus callosum agenesis (7%), arachnoid cyst (3%), porencephalic cyst (3%) and single ventricle (3%). A classical Tessiers operation was performed in the initial 30 cases. However, since 1988, we have been performing a single stage hemiorbital advancement and repair of the encephalocele. There were three deaths, one due to pneumonia and two due to fulminant meningitis. Twenty-two patients (22%) had postoperative CSF leak, of which five required lumboperitoneal shunt placement. We believe that hemiorbital advancement offers satisfactory results with less morbidity than the Tessiers operation.

A clinicopathological and molecular analysis of glioblastoma multiforme with long-term survival.

The median survival time of patients with glioblastoma multiforme (GBM) is 12 months, and only 3-5% of patients survive longer than 3 years. We performed histomorphological and detailed molecular analyses of seven long-term survivors of GBM to identify any prognostic factors that potentially contribute to survival. Morphology and immunohistochemistry for p53, phosphatase and tensin homologue (PTEN) and epidermal growth factor receptor (EGFR) protein expression were investigated. EGFR amplification and 1p/19q deletion were assessed by fluorescent in situ hybridization. The O6-methylguanine-DNA methyltransferase (MGMT) gene methylation status was evaluated by performing methylation-specific polymerase chain reaction assays. All tumors were classical GBMs and no significant oligodendroglial differentiation was noted. The majority showed EGFR amplification (4/7), PTEN protein expression (6/7) and MGMT promoter methylation (5/6). Immunopositivity for p53 was noted in three of seven patients. Deletion of chromosome 1p/19q, either isolated or combined, was not identified in any of the se patients. All patients were treated by gross total resection followed by radiotherapy; six patients received additional temozolomide treatment. A relatively young age of onset (48 years), with a high MGMT promoter methylation and PTEN protein expression were favorable factors for long-term survival. The presence of EGFR amplification indicates that more than a single factor determines survival in GBM.

Intramedullary tuberculoma of the spinal cord: a series of 10 cases

OBJECTIVE Involvement of vertebral column is common in tuberculosis but intramedullary tuberculomas are rare. We report a series of ten cases of intramedullary tuberculomas, which, to the best of our knowledge, is the largest series of biopsy proven intramedullary tuberculomas in English literature. METHODS During a period of 16 years (1985-2000), ten cases of intramedullary tuberculomas were diagnosed in our department. Of these, eight cases were histologically proven intramedullary tuberculomas. The clinical profile, radiological data and histological slides were reviewed. RESULTS Age ranged from 18 to 45 years (mean 29.7 years) and there was slight male preponderance (six men, four women). Duration of symptom varied from 3 to 20 months (mean 11.5 months). All of them presented with motor weakness and sensory impairment. Most common site of involvement was dorsal cord followed by cervical, cervicodorsal and dorsolumbar regions. Three patients had associated involvement of lungs, cervical lymphnodes, and brain, and one patient had past history of tuberculous meningitis. Two patients were treated conservatively but surgical excision was done in eight cases followed by medical treatment. CONCLUSION Radiologically, intramedullary tuberculomas should be differentiated from other space occupying lesions (SOL) to avoid unnecessary surgery especially in those patients with tuberculosis of the other organs. The incidence of intramedullary tuberculomas is likely to increase with a rise in the incidence of AIDS.

Pediatric pituitary adenoma: a series of 42 patients

Pituitary adenomas are uncommon in childhood. This report describes the presentation, endocrinological profile, management and outcome of 42 children with pituitary adenomas. The majority of the tumors were functioning adenomas (40/42, 95.2%). Only two patients (4.8%) had non-functioning tumors. Amongst the functioning tumors, there were 20 patients (47.6%) with prolactinomas, 11 patients (26.2%) with Cushings disease and nine patients (21.4%) with growth hormone (GH)-secreting adenomas. The most common presenting features were endocrinopathy and visual disturbances. The majority of tumors were macroadenomas, with only eight patients (all with Cushings disease) having a microadenoma. Transsphenoidal tumor decompression was performed in most cases (71.4%). Complications following transcranial surgery were more frequent when compared to transsphenoidal surgery. There was one death following surgery. Response to radiotherapy was satisfactory. Overall, 67.6% of patients achieved endocrinological remission. Of these, 89% of the children with GH-secreting tumors and 100% of the children with Cushings disease achieved remission. We conclude that the transsphenoidal approach is effective and safe in surgery for pituitary adenomas in children and is the procedure of choice if there is no contraindication. The combination of surgery and radiotherapy, as well as medical therapy with bromocriptine, achieves good results in the management of these uncommon tumors.

Gamma knife radiosurgery for glomus jugulare tumors: therapeutic advantages of minimalism in the skull base.

CONTEXT Glomus jugulare (GJ) tumors are paragangliomas found in the region of the jugular foramen. Surgery with/without embolization and conventional radiotherapy has been the traditional management option. AIM To analyze the efficacy of gamma knife radiosurgery (GKS) as a primary or an adjunctive form of therapy. SETTINGS AND DESIGN A retrospective analysis of patients who received GKS at a tertiary neurosurgical center was performed. MATERIALS AND METHODS Of the 1601 patients who underwent GKS from 1997 to 2006, 24 patients with GJ underwent 25 procedures. RESULTS The average age of the cohort was 46.6 years (range, 22-76 years) and the male to female ratio was 1:2. The most common neurological deficit was IX, X, XI cranial nerve paresis (15/24). Fifteen patients received primary GKS. Mean tumor size was 8.7 cc (range 1.1-17.2 cc). The coverage achieved was 93.1% (range 90-97%) using a mean tumor margin dose of 16.4 Gy (range 12-25 Gy) at a mean isodose of 49.5% (range 45-50%). Thirteen patients (six primary and seven secondary) were available for follow-up at a median interval of 24 months (range seven to 48 months). The average tumor size was 7.9 cc (range 1.1-17.2 cc). Using a mean tumor margin dose of 16.3 Gy (range 12-20 Gy) 93.6% coverage (range 91-97%) was achieved. Six patients improved clinically. A single patient developed transient trigeminal neuralgia. Magnetic resonance imaging follow-up was available for 10 patients; seven recorded a decrease in size. There was no tumor progression. CONCLUSIONS Gamma knife radiosurgery is a safe and effective primary and secondary modality of treatment for GJ.

Characterization of molecular genetic alterations in GBMs highlights a distinctive molecular profile in young adults.

To evaluate age-related differences in histopathologic and molecular profile of glioblastomas (GBMs) at various age groups, with special reference to TP53 mutation, epidermal growth factor receptor (EGFR) amplification, EGFR vIII mutant, PTEN deletion, and IDH1 mutation. Agewise GBM incidence was calculated over a period of 5 years (2005 to 2009). Seventy-five GBMs were selected for molecular analysis. Majority of cases were in the age group of 41 to 60 years, and mean age was 43.6 years. Histology of all 75 cases selected for molecular profiling was identical. Primary adult GBMs showed EGFR amplification and PTEN deletion in majority (37.3% and 54.9%, respectively). TP53 and IDH1 mutations were rare (11.8% cases each). In secondary GBMs, TP53 (66.7%) and IDH1 mutations (44.4%) were most frequent. PTEN deletion was seen in 33.3% and none had EGFR amplification. Pediatric GBMs (<18 y) harbored frequent TP53 mutations (46.7%) and PTEN deletion in 40%. IDH1 mutations and EGFR amplification were absent. The molecular profile of primary GBMs in young adults (19 to 40 y) was distinctly different from that of adults older than 40 years. TP53 mutation was present in 20% cases. The frequency of EGFR amplification (13.3%) and PTEN deletion (33.3%) was significantly low (P=0.028 and 0.046, respectively). IDH1 mutation, which is rare in primary adult GBMs, was present in 40% of cases. Molecular heterogeneity exists within GBMs of different age cohorts. The molecular profile of GBMs in young adults is distinctly different. Thus, there is a strong need for further studies in various age groups to provide guidelines for therapeutic targeting.

Correlation of diagnostic yield of stereotactic brain biopsy with number of biopsy bits and site of the lesion

Our objective was to examine the reliability of histological diagnosis achieved vis a vis the number of biopsy bits obtained along a single trajectory of the stereotactic needle. A retrospective analysis of stereotactic biopsies performed in a single tertiary care neurosciences center, during a period of 11 years, between 1995 to 2005 was done. The overall diagnostic accuracy achieved on histopathology was correlated with the number of bits obtained by stereotactic biopsy. A total of 86 cases were analyzed, which consisted of 58 males and 28 females. Age ranged from 6 to 75 years, with a mean age of 36.1 years. Twenty percent of the patients were in the pediatric age group and 15% were ≥60 years of age. Most common sites biopsied were thalamus/basal ganglia (55.8%), followed by eloquent areas and other sites. A definitive histological diagnosis was established in 70 cases (diagnostic yield, 81.3%), which encompassed 65 neoplastic and 5 nonneoplastic lesions. Astrocytic lesions, the most common, include 10 pilocytic astrocytomas (PA), 29 diffuse astrocytomas (DA), 11 anaplastic astrocytomas (AA), and 7 glioblastoma multiforme (GBM). In 16 cases no definite histological diagnosis could be offered. The number of biopsies ranged between 1 and 6 bits (mean, 2; median, 1). The majority (68.7%) of the biopsies were 1 or 2-bits. The diagnostic accuracy increased from 76.5% for single biopsies to 84% and 88.2% for 2 and 3 bits, respectively, and 100% for biopsies with 5 to 6 bits. Overall, a trend of higher diagnostic yield was seen in cases with more biopsies when compared with single bit biopsies. Thus, this small series confirms that stereotactic procedures involving multiple bits are associated with a high diagnostic yield.