Poodipedi Sarat Chandra

FDG-PET/MRI coregistration and diffusion-tensor imaging distinguish epileptogenic tubers and cortex in patients with tuberous sclerosis complex : A preliminary report

Summary:  Purpose: Patients with tuberous sclerosis complex (TSC) are potential surgical candidates if the epileptogenic region(s) can be accurately identified. This retrospective study determined whether FDG‐PET/MRI coregistration and diffusion‐tensor imaging (DTI) showed better accuracy in the localization of epileptogenic cortex than structural MRI in TSC patients.

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%).

Cardiovascular autonomic functions in well-controlled and intractable partial epilepsies.

BACKGROUND Epilepsy is associated with imbalance of sympathetic and parasympathetic activity which may lead to sudden unexplained death in epilepsy (SUDEP). Well-controlled (WcE) and intractable epilepsy (IE) subjects may present different autonomic profiles, which can be helpful in explaining the predisposition of the latter to SUDEP. PURPOSE To compare inter-ictal cardiovascular autonomic function in subjects with partial WcE and IE. METHODS Thirty WcE and 31 IE subjects underwent a battery of autonomic function tests: deep breathing, Valsalva maneuver, isometric exercise, cold pressor and tilt-table. Autonomic tone was assessed by heart rate variability (HRV). Their autonomic severity score and anxiety status was also assessed. RESULTS IE subjects had elevated low frequency component (52.0 vs. 37.6, p=0.047) and decremented high frequency component (114 vs. 397, p=0.013) of HRV and higher diastolic BP (75.62+/-9.77 vs. 68.64+/-0.43, p=0.036). In deep breathing test, they had lesser HR changes (20+/-10.18 vs. 29.68+/-11.23, p=0.007) and lower E:I (1.29+/-0.16 vs. 1.43+/-0.21, p=0.008). IE subjects had higher dysautonomia (chi square 165.0, p<0.0001). CONCLUSIONS We observed a higher vasomotor tone, higher sympathetic tone, lower parasympathetic tone, lower parasympathetic reactivity and more severe dysautonomia in the IE subjects. Refractoriness may lead to an alteration in cardiovascular autonomic regulation, which might be a predisposing factor for SUDEP.

Trigeminal schwannomas: Experience with 68 cases

Trigeminal schwannomas (TS) are rare. Only a couple of series involving a large number of cases have been reported. In the present study we aimed to analyse the clinical characteristics of TS, the surgical approaches used to treat TS, and the outcomes for patients undergoing surgical treatment for TS via retrospective analysis of departmental records. Data for 68 patients treated for TS in the Department of Neurosurgery at the All India Institute of Medical Sciences between January 1993 and December 2005 were analysed. Most patients were in the fourth decade of life, with the duration of symptoms ranging from 1 month to 13 years. Twenty-nine TSs were classified as type A, 13 as type B and 26 as type C, depending upon size. A skull base approach was used in every surgically treated case. Of the 46 patients for whom radiological follow-up data were available, complete tumour excision was achieved in 35 cases (76%). Follow-up ranged from 3 months to 12 years (mean 62 months). One patient died and nine (15%) had permanent morbidity in the form of corneal opacity (5) or facial (2) or trochlear (2) nerve palsy. We conclude that trigeminal neuromas are best treated by total surgical resection, which yields acceptable results with low rates of mortality and permanent morbidity.

FAT1 acts as an upstream regulator of oncogenic and inflammatory pathways, via PDCD4, in glioma cells

Glioblastoma multiforme (GBM) is the most aggressive and the commonest primary brain tumor with a tendency for local invasiveness. The pathways of neoplasia, invasion and inflammation are inextricably linked in cancer and aberrations in several regulatory pathways for these processes have been identified. Here we have studied the FAT1 (Homo sapiens FAT tumor-suppressor homolog 1 (Drosophila)) gene to identify its role in the tumorigenecity of the gliomas. The expression of FAT1 was found to be high in grade IV glioma cell lines (U87MG, A172, U373MG and T98G) but low in grade III glioma cell lines (GOS3 and SW1088). Two cell lines (U87MG and A172) with high FAT1 expression were chosen for in vitro FAT1-knockdown studies. FAT1 knockdown by small interfering RNA resulted in decreased migration and invasion of both the cell lines along with increased expression of the tumor-suppressor gene programmed cell death 4 (PDCD4). Increased PDCD4 expression led to the attenuation of activator protein-1 (AP-1) transcription by inhibiting c-Jun phosphorylation and resulted in concomitant decrease in the expression of AP-1-target genes like MMP3, VEGF-C and PLAU, the pro-inflammatory regulator COX-2 and cytokines IL1β and IL-6. Conversely, simultaneous silencing of PDCD4 and FAT1 in these cells significantly enhanced AP-1 activity and expression of its target genes, resulting in increase in mediators of inflammation and in enhanced migratory and invasive properties of the cells. We also observed a negative correlation between the expression of FAT1 and PDCD4 (P=0.0145), a positive correlation between the expression of FAT1 and COX-2 (P=0.048) and a similar positive trend between FAT1 and IL-6 expression in 35 primary human GBM samples studied. Taken together, this study identifies a novel signaling mechanism mediated by FAT1 in regulating the activity of PDCD4 and thereby the key transcription factor AP-1, which then affects known mediators of neoplasia and inflammation.

Endoscopic Third Ventriculostomy

Endoscopic third ventriculostomy (ETV) is one of the efficacious surgical options available for obstructive hydrocephalus, and is preferable to a ventriculoperitoneal shunt in those eligible. We retrospectively studied 115 cases, who underwent ETV at our institute over the last 5 years. Thirty-eight patients were infants. Major indications for ETV were aqueductal stenosis (n = 60/115, 52.2%), Dandy-Walker malformation (15/115, 13%), associated arachnoid cyst (n = 13/115, 11.3%) and post-meningitic hydrocephalus (n = 12/115, 10.4%). Average duration of the follow-up was 10.6 months. Ninety-nine patients (86.1%) showed clinical improvement after surgery. Clinical improvement was seen in 27 out of 38 infants (71%) followed up. ETV is a highly effective tool in all age groups of patients for the management of hydrocephalus. Clinical features should be considered as indications of the success or failure of ventriculostomy in infants who have low-pressure hydrocephalus.

Hemispherotomy for intractable epilepsy

CONTEXT Hemispherotomy is a surgical procedure for hemispheric disconnection. It is a technically demanding surgery. Our experience is presented here. AIMS To validate and compare the two techniques for hemispherotomy performed in patients with intractable epilepsies. SETTINGS AND DESIGN A retrospective study 2001-March 2007: Nineteen cases of hemispherotomies from a total of 462 cases operated for intractable epilepsy. MATERIALS AND METHODS All the cases operated for intractable epilepsy underwent a complete epilepsy surgery workup. Age range 4-23 years (mean 5.2 years), 14 males. The seizure frequency ranged from 2-200 episodes per day; four were in status; three in epilepsia partialis continua. The pathologies included Rasmussens, hemimegelencephaly (unilateral hemispheric enlargement with severe cortical and subcortical changes), hemispheric cortical dysplasia, post-stroke, post-traumatic encephalomalacia and encephalopathy of unknown etiology. The techniques of surgery included vertical parasaggital approach and peri-insular hemispherotomy. Neuronavigation was used in seven cases. RESULTS Class I outcome [Engels] was seen in 18 cases and Class II in one assessed at 32-198 weeks of follow-up. The four patients in status epilepticus had Class I outcome. Four patients had an initial worsening of weakness which improved to preoperative level in five to eight weeks. Power actually improved in three other patients at 32-36 weeks of follow-up, but hand grip weakness persisted. In all the other patients, power continued to be as in preoperative state. Cognitive profile improved in all patients and 11 cases returned back to school. CONCLUSIONS Both techniques were equally effective, the procedure itself is very effective when indicated. Four of our cases were quite sick and were undertaken for this procedure on a semi-emergency basis.

Effect of risk-stratified, protocol-based perioperative chemoprophylaxis on nosocomial infection rates in a series of 31 927 consecutive neurosurgical procedures (1994-2006).

OBJECTIVEAlthough the use of prophylactic antibiotics has been shown to significantly decrease the incidence of meningitis after neurosurgery, its effect on extra–neurosurgical-site infections has not been documented. The authors explore the effect of risk-stratified, protocol-based perioperative antibiotic prophylaxis on nosocomial infections in an audit of 31 927 consecutive routine and emergency neurosurgical procedures. METHODSInfection rates were objectively quantified by bacteriological positivity on culture of cerebrospinal fluid (CSF), blood, urine, wound swab, and tracheal aspirate samples derived from patients with clinicoradiological features of sepsis. Infections were recorded as pulmonary, wound, blood, CSF, and urinary. The total numbers of hospital-acquired infections and the number of patients infected were also recorded. A protocol of perioperative antibiotic prophylaxis of variable duration stratified by patient risk factors was introduced in 2000, which was chosen as the historical turning point. The χ2 test was used to compare infection rates. A P value of <0.05 was considered significant. RESULTSA total of 31 927 procedures were performed during the study period 1994–2006; 5171 culture-proven hospital-acquired infections (16.2%) developed in 3686 patients (11.6%). The most common infections were pulmonary (4.4%), followed by bloodstream (3.5%), urinary (3.0%), CSF (2.9%), and wound (2.5%). The incidence of positive tracheal, CSF, blood, wound, and urine cultures decreased significantly after 2000. Chemoprophylaxis, however, altered the prevalent bacterial flora and may have led to the emergence of methicillin-resistant Staphylococcus aureus. CONCLUSIONA risk-stratified protocol of perioperative antibiotic prophylaxis may help to significantly decrease not only neurosurgical, but also extra–neurosurgical-site body fluid bacteriological culture positivity.

Primary spontaneous CSF rhinorrhea through the clivus: Possible etiopathology

Primary spontaneous cerebrospinal fluid (CSF) rhinorrhea is rare. Only two such cases with a defect in the clivus have been previously reported in the world literature. The purpose of this report is not to discuss the operative approach or results but the etiopathogenesis of the defect at this very rare site. One patient had a defect in the posterior wall of the sphenoid sinus, just caudal to the dorsum sellae. In the other, a psuedomeningocele (thickened arachnoid outpouching) was found protruding into the sphenoid sinus through a defect in the middle of the clivus. Both cases were successfully managed with transsphenoidal surgery. Two additional cases of primary spontaneous CSF rhinorrhea through a defect in clivus are reported. The possible mechanism of the fistulae are discussed.

Health-related quality of life using QOLIE-31: before and after epilepsy surgery a prospective study at a tertiary care center

BACKGROUND Outcome following epilepsy surgery has traditionally been measured in terms of relief of seizures. However, changes in health-related quality of life (HRQOL) after surgery for intractable epilepsy are also important to document. There are no studies on the Indian population which assess the outcome of epilepsy surgery in terms of HRQOL. MATERIALS AND METHODS We conducted a prospective study on the patients undergoing epilepsy surgery for intractable seizures, between February 2004 and May 2006 at our center. All patients cleared for epilepsy surgery by the epilepsy surgery team were taken up for study. All patients RESULTS Thirty-six patients satisfying the inclusion/exclusion criteria were included in the analysis. Twenty-nine of these (Group 1) had good seizure outcome (Engel 1 and 2), while seven patients (Group 2) had poor seizure outcome (Engel 3 and 4) at six months. Overall, 77% of all study patients were completely seizure-free at follow-up. There was no baseline difference in the seven domains of QOLIE-31 between the two groups. There was very significant improvement (P value>0.005 using paired sample T test) in all the domains of QOLIE-31 in the good outcome group after surgery. Health-related quality of life improvement was seen in all the domains in the poor outcome group also, however, it was statistically significant only for the following parameters: seizure worry, overall QOL, emotional wellbeing, energy fatigue and social functioning domains. Improvement in seizure worry, overall QOL, emotional wellbeing and social functioning was significantly more in Group 1 as compared to Group 2. CONCLUSION Complete seizure-free state after surgery is associated with very significant improvement in HRQOL parameters. Several, but not all parameters of HRQOL as assessed by QOLIE-31, improved after surgery even in the poor seizure outcome group. The improvement in domains of seizure worry, overall QOL, emotional wellbeing and social functioning is significantly more in those patients in whom complete seizure-free state is achieved.