Background and importance Intracranial mature cystic teratomas are benign neoplasms that commonly occur at the midline. Mature cystic teratomas at the cerebellopontine (CP) angle are very rare. They are unique germ cell tumours curable by safe total surgical resection and have good prognosis. This case report documents the clinical, radiological, histological features and operative findings of mature cystic teratoma at CP angle.Clinical presentation We present a rare case of a mature cystic teratoma at the CP angle in a 24-year-old woman who presented with brainstem compression and cranial nerve deficits. Brain MRI showed atypical findings like hyperintense areas in both T1 and T2 weighted images, calcification and diffusion restriction in part of the lesion. She underwent near total resection of the tumour via right retrosigmoid approach. Intraoperatively, the lesion was intra-arachnoidal unlike schwannomas and the cyst contained sebum-like material, fibrous areas with calcification which are unusual features of common CP angle tumours. Histopathological examination showed well differentiated mature tissues from all three germinal layers and confirmed the diagnosis of a mature cystic teratoma arising from the right CP angle. Patient had good outcome with neurologic recovery.Conclusions Mature cystic teratoma is a rare clinical entity and should be considered in patients with CP angle tumours when there are atypical findings in brain MRI imaging. Cysts with sebum-like material, fibrous areas with calcification and poor tumour-arachnoid plane intraoperatively strongly suggest the possibility of mature cystic teratoma.

Introduction: Unlike adult gliomas, the utility of combined application of awake anesthesia and intraoperative neurophysiological monitoring (IONM) for maximal safe resection in eloquent region gliomas (ERG) has not been established for pediatric population while it remains unexplored in preadolescents (below 11 years old). Case Presentation: We report 2 cases of awake craniotomy with IONM in an 8 and 9 year old for safe maximal resection of ERG. In both the cases, repeated preoperative visits of the operating room was performed to familiarize and educate the children about intraoperative communication, comfortable positioning, and neurological assessment. Under conscious sedation protocol, cortical and subcortical mapping, and electrocorticography, gross total resection was achieved. In both the cases, there were no postoperative neurodeficits or perioperative complications. Conclusion: Our 2 cases illustrate the first instance of successful use of awake IONM for maximal safe resection of ERG in preadolescent age-group. We believe, with proper preoperative planning and careful titration of anesthetics, it is safe and feasible. The blanket notion that preadolescent age-group should be excluded from awake mapping needs to be challenged, rather curated on a case basis.

Introduction: Awake craniotomy in pediatric group is challenging.Its success depends on maintaining a good rapport with the child, careful titration of anesthetic agents, and managing intraoperative challenges.Methodology/Description: An awake craniotomy with neurophysiological monitoring was planned for this 10-year-old girl with lesion at the right motor cortex.After adequate counseling, she was acquainted to the environment with repeated visits to the perioperative suite.She was also familiarized with the motor function testing during surgery.Under standard monitoring, propofol infusion at 100 to 150 μg/kg/min and fentanyl infusion at 0.5 μg/kg/h were initiated after a bolus dose of 15 μg of fentanyl.A 22-gauge cannula was inserted in the right radial artery for blood pressure monitoring.Scalp block was performed with mixture of 2% lignocaine with adrenaline and 0.5% ropivacaine (7 mL each).Sedation was continued during painful procedures like pin fixation, insertion of needle electrodes, and all steps of craniotomy.Throughout the procedure oxygen was given through nasal prongs and her respiration was monitored with the chest leads used for ECG.Propofol infusion was stopped after exposure of duramater.She was comfortable throughout the procedure and co-operated for motor assessment of limbs.Careful titration of sedatives helped in electrophysiological assessment like cortical and subcortical mapping and ECoG.Propofol infusion was restarted after dural closure.No significant complications occurred and the patient recovered without any motor deficits. Conclusion:Our case report illustrates that with proper planning and careful titration of anesthetics, awake craniotomy along with intraoperative neurophysiological monitoring is safe and feasible in pediatric age group.

Spontaneous electrical activity of brain – electroencephalogram (EEG) – is of significant amplitude (~100 μV) and can mask the small electrical activities produced by stimulation of a specific sensory modality. The strategy to extract electrical activity produced by the auditory system alone (<1 μV) is to provide repetitive auditory stimuli and to average the resulting electrical responses recorded from the scalp, so that time-locked events alone would stand out, with cancellation of random noise, which in this case is background EEG.

Introduction: Intraoperative neurophysiological monitoring (IONM) is the standard of care for a wide range of surgeries where neurological insult is anticipated. The choice of anaesthesia depends on the signals being monitored, patient’s comorbidities and the intraoperative course of physiological parameters. We report here a retrospective case series to highlight the anaesthetic considerations in various neurosurgeries. Methods: We reviewed all neurosurgical cases (n = 43) which required IONM in the last 3 months (since the inception of IONM services in our hospital). This included cerebellopontine angle tumours (n = 15), compressive spinal cord myelopathies (n = 10), spinal cord tumours (n = 4), tumours of caudaequina (n = 3), brain tumours in the vicinity of speech area (n = 4), brain tumours in the vicinity of motor area (n = 3), sellar-parasellar tumours (n = 2), trigeminal neuralgia (n = 1) and spinal nerve root tumour (n = 1). Various neurophysiological techniques used in these cases for neuromonitoring included transcranial electrical motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), free-run and triggered electromyography (EMG), direct cranial and peripheral nerve stimulation, motor mapping, language mapping, bulb cavernous reflex testing, raw and processed electroencephalography (EEG). In cases requiring MEPs and SSEPs, we used total intravenous anaesthesia and avoided relaxants. Soft bite block helped avoid tongue bites. In cases where EMG alone was monitored, only muscle relaxants had to be avoided and inhalational agents could be used. Awake craniotomy under local anaesthesia with an ‘asleep-awake-asleep’ technique was used for language mapping. Systemic blood pressure and core body temperature also had to be maintained for optimal neurophysiologic signals. EEG and bispectral index monitoring were used to assess the depth of anaesthesia. Results: By customising anaesthesia according to neurophysiological requirements, we achieved good baseline monitor ability in 42/43 cases (one patient had severe neurological deficit that baseline signals could not be recorded). Monitoring was successful in all 42 cases except one (monitoring had to be discontinued in a case, as inhalational agent was kept above 0.5 minimum alveolar concentration). Conclusion: Good signal acquisition for a reliable neuromonitoring is teamwork between neurosurgeons, surgical neurophysiologists and anaesthesiologists. Inhaled anaesthetics are to be used frugally/not at all, in cases requiring MEP monitoring.

Study background: Measurement of delivered pharyngeal pressure during continuous positive airway pressure (CPAP) therapy is not in routine practice due to lack of a simple and affordable technique of intrapharyngeal pressure measurement. To overcome the lack of the gold standard solid-state catheter-tip pressure measurement technology in our set up, we improvised a novel method of pressure measurement and tested its validity in a simulated pharynx.METHODS:A low-cost pressure transducer was improvised by attaching an orogastric tube to its one end. The other end of the orogastric tube was sealed into an artificial pharynx - a 20 ml syringe. The pressure transducer readings were compared with that obtained by a digital manometer attached to the tip of the syringe. Bland-Altman statistic was used to quantify the measurement reliability of the novel method against the digital manometer. Effect of tube length on the measurement agreement was also studied. The developed technique was applied in new-borns.RESULTS & CONCLUSION:Pressures measured by this technique were in good agreement with that obtained using a digital manometer. This technique has the potential to be used as an alternative to catheter-tip pressure transducers for bedside pharyngeal pressure measurement in new-born babies, especially in under-resourced setups.

Introduction: Intraoperative mapping of language function assumes importance in patients undergoing resection of tumours in proximity to Broca’s area. Optimal stimulation protocol for effecting a speech arrest is challenging because of the risk of seizure due to high frequency, long duration electrical stimulation in awake subjects. We report a case series to present our experience with an improvised protocol for direct cortical electrical stimulation for language mapping. Methods: A total of three cases of language mapping have been carried out since the inception (i.e., about 1 month) of neurophysiological monitoring services in our institute. All the patients (two female and one male) had tumours close to the anatomical Broca’s area as determined by pre-operative magnetic resonance imaging (MRI). In one patient, a functional MRI confirmed the same. All were right-handed. Baseline assessment of language function revealed deficits in all the patients. Awake craniotomy was carried out under neuron avigation guidance. Verbal fluency and object recognition tasks were carried out. Stimulation protocol consisted of 1000 ms duration electrical pulse of biphasic polarity presented at 60 Hz for 7 s, repeated intermittently. Results: All patients had language area in the left cerebral hemisphere. Using this stimulation protocol, a current, as small as 5 mA, caused speech arrest and defined the expressive language area. No patient developed intraoperative seizure or did anyone develop new language deficit post- surgery. Conclusion: Our limited experience suggests that our language mapping stimulation protocol has been effective in causing speech arrest without inducing seizures during awake craniotomy for frontal lobe surgeries. Intraoperative language mapping should be considered as the standard of care in such surgeries.

Background The worldwide burden of diabetes in 2030 is projected around 552 million. Diabetes leads to higher risk for cardiovascular diseases (CVD). Altered cardiac autonomic function (CAF) measured by heart rate variability (HRV) is observed in early stages of diabetes but the relationship between impaired fasting glucose (IFG) and HRV is still debatable. The aim of the study was to evaluate the association between CAF, oxidative stress, insulin resistance (IR), and inflammatory response in IFG subjects. Subjects and Methods Cross-sectional blinded study. Volunteers recruited from health awareness camps underwent CAF and biochemical tests. Based on fasting plasma glucose (FPG) participants (n = 123) were divided into two groups, normal fasting glucose (n = 76) and IFG (n = 47). The comparison of parameters between the groups was carried out using student t test and Mann-Whitney U test for parametric and non-parametric data respectively. The correlation between the parameters was analyzed by Spearman's rank correlation using SPSS 13.0. Results The resting cardiovagal modulation parameters, heart rate response to forced timed breathing, and orthostatic stress were reduced in IFG subjects. Fasting plasma lipid profile, coronary atherogenic lipid risk factors, IR, thiobarbituric acid reactive substance (TBARS), high sensitive C-reactive protein, and tumor necrosis factor alpha were increased and total antioxidant capacity (TAC) was decreased significantly in IFG group but no significant alteration was observed in high-density lipoprotein (HDL-c). Cardiovagal modulation parameters were negatively correlated with triglycerides, FPG, insulin, IR, TBARS, and inflammatory markers and positively with TAC. Conclusion There is a continuous interplay between the altered CAF, hyperinsulinemia, IR, oxidative stress parameters, inflammatory response, and IFG in which one factor perpetuates another leading to the progression of disease.

Background. Peripheral venous thrombophlebitis (PVT) is a common complication of intravenous cannulation, occurring in about 30% of patients. We evaluated the effect of elective re-siting of intravenous cannulae every 48 hours on the incidence and severity of PVT in patients receiving intravenous fluids/drugs.Methods. We randomized 42 patients who were admitted for major abdominal surgery to either the control or study group(n=21 in either group). Informed consent was obtained from all of them. Cannulae in the control group were remove only if the site became painful, the cannula got dislodged or there were signs and symptoms suggestive of PVT, namely pain, erythema, swelling, excessive warmth or a palpable venous cord. Cannulae in the study group were changed and re-sited electively every 48 hours. All the patients were examined every 24 hours for signs and symptoms of PVT at the current and previous sites of infusion.Results. The incidence of PVT was 100% (21/21) in the control group and only 9.5% (2/21) in the study group (p < 0.0001). The severity of PVT was also less in the study group compared with that in the control group. Day-wise correlation of the incidence of PVT showed that 82.6% of the episodes of PVT occurred on day 3.Conclusion. Elective re-siting of intravenous cannulae every 48 hours results in a significant reduction in the incidence and severity of PVT. We recommend that this should be adopted as standard practice in managing all patients who require prolonged intravenous therapy.