Development and Validation of a Multivariable Model to Predict Surgical Outcome in Patients with Chiari malformations.

Background: Surgical outcome predictive models for Chiari malformations (CM) which are applicable to all age groups and simple enough to use on outpatient basis are lacking. Objective: The aim of this study was to develop and validate a preoperative index for predicting long-term outcomes in Chiari 1 (CM1) and Chiari 0 (CM0) malformations. Materials and Methods: It was a single-institution, ambidirectional, cohort study from 2014 to 2019, having patients between 5 to 70 years. Outcome was assessed using Chicago Chiari outcome score (CCOS) over 2 years follow-up. Preoperative clinical and radiological factors were analyzed using Chi-square test and Mann Whitney U test, in relation to CCOS and those attaining P value ≤0.05, were used to develop model - Chiari Outcome Predictive Index (COPI). COPI was internally validated using 10-fold cross-validation and c-statistic for discrimination. Results: A total of 88 patients (66 in development and 22 in validation cohort) were included in the study. Outcome was negatively associated with presence of motor, sensory or cranial nerve symptoms, poor functional status, basilar invagination, and tonsillar descent. It was positively associated with shorter duration of presenting symptom (<9 months) and syrinx diameter <6 mm. COPI predicted CCOS with 91.1% accuracy (10-fold cross-validation). It had excellent discrimination for improved outcome (c = 0.968 in development and 0.976 in validation cohort), at threshold index of -1. Conclusions: COPI is simple tool that can be administered in outpatient setting. It can facilitate evidence-based preoperative counseling of patients, to help them develop reasonable expectations regarding surgical outcomes.

Techniques and Nuances in Ventriculoperitoneal Shunt Surgery.

BACKGROUND: Ventriculoperitoneal shunt surgery (VPS) is a simple solution to the problem of hydrocephalus. However, it is associated with significant complications. Meticulous attention to a variety of factors, techniques, and nuances in VPS can reduce these complications. OBJECTIVE: To review the various techniques and nuances during the different stages of VPS. METHODS AND MATERIAL: PubMed search for original and review articles dealing with various techniques used during VPS. RESULTS: Thorough preoperative planning for VPS reduces operative time and complications. A standardized shunt surgery protocol significantly reduces shunt infection. Good and appropriate surgical technique can enhance the safety of the procedure. Anterior entry point is better than posterior entry point. Shunt tip should be away from choroid plexus, but the exact location is not vital for shunt survival. Proper placement of the shunt in the subgaleal and subcutaneous plane reduces wound and skin breakdown over the shunt. The trocar and laparoscopic methods to access the peritoneum are associated with fewer distal obstructions compared to mini-laparotomy. Perioperative antibiotic prophylaxis, use of antibiotic-impregnated shunts, and sutures are proven techniques to reduce shunt infection. CONCLUSIONS: Preoperative planning, a standardized shunt surgery protocol, good surgical technique, gentle tissue handling, and short surgery duration are essential to reduce VPS complications. Specifically, use of anterior entry point, correct tunneling of the shunt in the subgaleal and subcutaneous plane, appropriate antibiotic prophylaxis, use of antibiotic-impregnated shunts, and meticulous skin closure using antimicrobial sutures can lead to a reduction in shunt malfunction and infection.

Moyamoya syndrome as a manifestation of varicella-associated cerebral vasculopathy-case report and review of literature.

BACKGROUND: Varicella-associated cerebral vasculopathy (VACV) is a serious complication of Varicella zoster virus (VZV) infection. VACV has protean manifestations, with varying clinical, radiological features and prognosis. CASE DESCRIPTION: Moyamoya syndrome (MMS) with VACV is reported in few cases in the past. All the patients were in paediatric age group, presenting with multiple episodes of transient ischemic attacks (TIAs) and infarct. Our case was a 10-year-old Indian girl with ischemic stroke due to VACV who was treated with intravenous acyclovir. She presented 11 months later with multiple episodes of TIAs. Her angiogram showed bilateral moyamoya vasculature. Acetazolamide challenge study revealed areas of hypoperfusion. Previously reported such cases had been treated medically with steroids and antiplatelets. Most of these patients had resolution of motor symptoms after long follow-up; however, this period was marred by recurrent symptoms. Our patient underwent cerebral revascularisation procedure, following which her TIAs resolved, there was improvement in her limb power and, according to her parents, her performance in school has improved at 2-year follow-up. CONCLUSION: MMS can be a manifestation of VACV and should be suspected in paediatric patient of non-east Asian population. These patients require treatment with intravenous acyclovir to inactivate the virus. Those with TIAs should undergo cerebral revascularisation procedures. Medical management should be reserved for patients with adequate collaterals.

Usefulness of stereotactic biopsy and neuroimaging in management of HIV-1 Clade C associated focal brain lesions with special focus on cerebral toxoplasmosis.

BACKGROUND: Focal brain lesions (FBL) in HIV/AIDS frequently pose a diagnostic dilemma as the etiology varies from infective (tuberculoma, toxoplasmosis and tuberculous abscesses) to neoplastic lesions like lymphoma. For determining etiology, advanced neuroimaging techniques, serological and molecular biological tests have been evolved with varying sensitivities/specificities. Stereotactic biopsy (STB) of the lesions is reserved for lesions unresponsive to appropriate therapy. OBJECTIVE AND METHODS: In this study, the diagnostic yield of neuroimaging [cranial CT (n=25), MRI (n=24), and Th201/99Tc SPECT scan (n=18)] is compared with histopathological diagnosis obtained by STB (n=21) or autopsy (n=4) in 25 HIV-1 subtype C seropositive individuals with FBL identified by neuroimaging with special reference to cerebral toxoplasmosis in an eighteen month study period (2006-2007). RESULTS AND CONCLUSION: Cerebral toxoplasmosis was the most frequent cause of FBL (21/25, 84%), followed by one case each of tuberculoma, progressive multifocal leukoencephalopathy (PML), primary central nervous system lymphoma (PCNSL) and measles inclusion body encephalitis (MIBE), the last two diagnosed at autopsy. Of the 21 cases of cerebral toxoplasmosis, definitive diagnosis with histopathological confirmation was available in 14/21 (66.6%), with indirect evidence suggesting probable toxoplasmosis in seven, all of whom responded to antitoxoplasma therapy. CT and MRI had comparable specificities (75%), while MRI had marginally higher sensitivity (85% versus 80.9%) in detecting multiple lesions. The positive predictive value of both CT and MRI was identical (94.4%), suggesting that CT maybe a cost effective screening tool in resource restricted settings, for evaluating FBL. Sensitivity of 99Tc SPECT scan for diagnosing inflammatory lesions was 75% but failed to differentiate PCNSL from toxoplasmosis. This study is the first of its kind from India analyzing FBL with specific focus on cerebral toxoplasmosis in the setting of HIV-1 subtype C.

Post-concussion syndrome: Correlation of neuropsychological deficits, structural lesions on magnetic resonance imaging and symptoms.

BACKGROUND: Post-concussion syndrome (PCS) associated with mild traumatic brain injury (MTBI) can cause long-lasting disabilities. Magnetic resonance imaging (MRI) evaluation in these patients may demonstrate structural lesions that correlate with functional deficits on neuropsychological testing. However, little is known about the significance of the relationship between structural lesions on MRI, functional deficits on neuropsychological evaluation and outcome in patients with MTBI. AIMS: To assess neuropsychological deficits and structural lesions on MRI in patients with PCS following MTBI, and to find correlation between these findings and PCS. SETTINGS AND DESIGN: Prospective, observational, cohort study in a tertiary hospital. MATERIALS AND METHODS: The study cohort included consecutive patients with MTBI (three months or more duration) and PCS. All the patients in the cohort had neuropsychological testing using the National Institute of Mental Health and Neurological Sciences Neuropsychological Battery for head injury and also MRI using T1, T2 and FLAIR sequences. Statistical analysis was done using Fisher's Exact test of significance. RESULTS: All the 20 patients evaluated had neuropsychological deficits. Eleven patients had lesions on MRI. Disturbances of sleep, behavior and memory and abnormalities in tests for mental speed were more frequent in patients with lesions on MRI, but were not statically significant (P = 0.08). Both the test modalities localized lesions predominantly to the frontal and temporal lobes. All the symptoms observed in the patients were associated with prefrontal dysfunction on neuropsychological testing. CONCLUSIONS: Prefrontal dysfunction is invariably associated with PCS following MTBI. Structural lesions on MRI may not always be present but when present may influence the degree or severity of the symptoms.

Reduction of functional brain connectivity in mild traumatic brain injury during working memory.

Working memory deficits are present in patients with mild traumatic brain injury (MTBI). Functional connectivity of different brain regions is required for adequate working memory. Brain injury is associated with disrupted connectivity due to microscopic axonal damage. In this investigation, we sought to investigate functional brain connectivity during working memory in MTBI patients. A sample of 30 MTBI patients and 30 age-, education-, and gender-matched normal controls were studied. Working memory was assessed with the Sternberg's verbal and visuo-spatial working memory tasks. Electro-encephalography (EEG) was recorded from 128 channels while subjects performed working memory tasks and during eyes closed resting condition. EEG coherence was computed in theta; lower and upper alpha; and lower and upper beta frequency bands during the encoding, retention, and retrieval stages of working memory as well as during eyes-closed rest. We found that the MTBI patients had impaired verbal and visuo-spatial working memory. The different stages of working memory were associated with poor intrahemispheric coherence in long-range (fronto-parietal) and mid-range (fronto-temporal and temporo-parietal) regions as well as poor interhemispheric coherence in the frontal and temporal regions in the MTBI patients. The deficit in coherence was present in theta, alpha, and beta frequency bands. However, the MTBI and the control group had comparable coherence values in intra- and inter-hemispheric regions during eyes closed rest. We suggest that the inter- and intra-hemispheric functional connectivity is impaired in MTBI during working memory performance.

Intensive care management of head injury patients without routine intracranial pressure monitoring.

BACKGROUND: Head injury contributes significantly to mortality and morbidity in India. Evaluation of the available trauma care facilities may help improve outcome. AIM: To evaluate the factors influencing the mortality of patients with head injury who had intensive care management and evolve strategies to improve outcome. SETTING AND DESIGN: Retrospective study in a tertiary hospital where intracranial pressure monitoring (ICPM) is not routinely practiced. MATERIALS AND METHODS: All patients with head injury managed in the intensive care unit in a two-year period were included. The factors evaluated were age, vital signs, Glasgow Coma scale score (GCS) at admission, pupillary light reflex (PR), oculocephalic reflex (OCR), hemodynamic stability, computerized tomography (CT) findings, diabetes mellitus, anemia, infections and abnormalities of serum sodium. RESULTS: We analyzed 208 patients (202 without ICPM). In-hospital mortality was 64 (31%). Only 24 (11.5%) patients were admitted within one hour of injury, while one-third arrived after six hours. The clinical factors (at admission) that influenced mortality included age, GCS, PR, OCR and diastolic blood pressure (DBP). Effacement of the basal cisterns in the initial and repeat CT scans, hyperglycemia, hemodynamic instability and serum sodium imbalances were associated with higher mortality. The independent predictors of mortality by logistic regression were initial GCS, DBP, hemodynamic instability and effacement of cisterns on repeat CT. CONCLUSIONS: Mortality following head injury is high. Pre-hospital emergency medical services are disorganized. The key to reducing mortality within the limitations of our current trauma system is maintenance of DBP>70 mmHg and SBP>90 mmHg from the time of first contact.

Cerebrovascular reactivity to carbon dioxide in the normal and abnormal cerebral hemispheres under anesthesia in patients with frontotemporal gliomas.

Cerebral pathology may alter the cerebrovascular reactivity to carbon dioxide (CO2). In the present study, in patients with brain tumors, we examined the cerebral vascular reactivity to CO2 in the cerebral hemispheres with and without tumors under intravenous and inhalational anesthesia. Twenty-nine patients undergoing craniotomy for frontotemporal gliomas were randomized to receive intravenous anesthesia with propofol or inhalational anesthesia with isoflurane. Cerebral blood flow velocity in the middle cerebral artery (VMCA) and pulsatality index were measured under normocapnia and hypocapnia in the normal cerebral hemisphere and the hemisphere with tumor. Hypocapnia significantly decreased the VMCA in both the cerebral hemispheres under both the anesthetic techniques (P < 0.006). The percentage change in VMCA was similar between the hemispheres with and without tumor both under isoflurane (3.45 +/- 4.11% on the normal side and 2.91 +/- 2.40% on the tumor side; mean difference 0.54 +/- 1.31%; 95% CI -2.18 to +3.27) and propofol anesthesia (2.32 +/- 2.64% on the normal side and 1.69 +/- 4.04% on the tumor side; mean difference 0.63 +/- 1.2%; 95% CI -1.83 to +3.10). The changes in pulsatality index also were not significantly different between the hemispheres. In conclusion, cerebrovascular response to hypocapnia is similar between the normal and the abnormal cerebral hemispheres both under intravenous and inhalational anesthesia.

Unilateral Moyamoya Phenomenon Due to MCA Occlusion in a Child Presenting with Intracerebral Hemorrhage.

SUMMARY: Spontaneous middle cerebral artery (MCA) occlusion leading to moyamoya phenomenon is different from classical moyamoya disease. Previous studies have reported such phenomena in adults with ischemic lesions, except for a solitary case in a child.We report a case of a ten-year old girl who presented with a deep intracerebral hematoma and a normal ipsilateral middle cerebral artery on initial evaluation by CT. Subsequently, on follow-up angiography, the ipsilateral MCA was occluded with evidence of unilateral basal lenticulostriate and transdural collateral supply causing a 'moyamoya' phenomenon. This report discusses a rare and interesting disease from the perspective of 'moyamoya' phenomenon and angiogenesis.

Does volume of extradural hematoma influence management strategy and outcome?

AIMS: To evaluate the management strategy of extradural hematomas (EDH), particularly with respect to its volume. METHODS AND MATERIALS: Two hundred and three patients with EDH and no other significant intracranial injuries were treated over a period of three years. RESULTS: The factors influencing management strategy and outcome were the Glasgow coma scale (GCS), volume of extradural hematoma (EDHV) and its location. The ultimate clinical outcome was significantly better in patients having EDHV of less than 30 ml. CONCLUSIONS: The key factors influencing the management strategy and clinical outcome are EDHV and GCS at the time of admission. A patient with EDH should not be considered for conservative management if EDHV is more than 30 ml and GCS is 13 or less.