Kavindra Nath

Measurement of cytotoxic and interstitial components of cerebral edema in acute hepatic failure by diffusion tensor imaging

To use diffusion tensor imaging (DTI) metrics for measuring cytotoxic and interstitial components of cerebral edema (CE) in acute hepatic failure (AHF) patients. CE is a major complication in patients with AHF.

Quantification of cerebral edema on diffusion tensor imaging in acute-on-chronic liver failure.

Cerebral edema is a major complication of acute liver failure but may also be seen in other forms of liver failure such as acute‐on‐chronic liver failure (ACLF) and chronic liver failure (CLF). ACLF develops in patients with previously well‐compensated chronic liver disease following acute hepatitis A or E superimposed on underlying liver cirrhosis. The aim of this study was to detect the occurrence, and determine the nature, of cerebral edema in patients with the defined subset of ACLF using diffusion tensor imaging (DTI) metrics. Twenty‐three patients with ACLF were studied and compared with 15 healthy controls and 15 patients with CLF. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), linear anisotropy (CL), planar anisotropy (CP), and spherical isotropy (CS) were calculated by selecting regions of interest in the white matter and deep grey matter of the brain. Significantly decreased FA and increased CS were observed in the anterior limb (ALIC) and posterior limb (PLIC) of the internal capsule and frontal white matter (P < 0.05) in patients with different grades (1–4) of ACLF when compared with healthy controls. No significant changes in MD and CP were seen in any brain region. However, significantly decreased CL was observed in the PLIC, caudate nuclei and putamen. In patients with CLF, significantly decreased FA with increased CS in the ALIC and PLIC along with significantly increased MD in the ALIC and caudate nuclei were observed. The presence of significantly decreased FA and CL and increased CS along with no significant change in MD and CP suggests the presence of both intracellular and extracellular components of cerebral edema in patients with ACLF. Copyright

Neurocysticercosis in patients with active epilepsy from the pig farming community of Lucknow district, north India

Epilepsy is a major health problem worldwide, and neurocysticercosis (NCC) is one of the important causes of epilepsy in the tropics. The present study was carried out in a rural pig farming community of north India to estimate the prevalence of NCC in patients with active epilepsy (AE) and to determine the associated risk factors. Based on 30-cluster sampling recommended by WHO, a total of 1640 individuals belonging to 294 families from 30 villages were enrolled in the study. Demographic and socio-economic details of all individuals and families were recorded. Individuals with AE were identified by door-to-door survey. NCC was diagnosed by clinical, immunological, neuroimaging (brain magnetic resonance imaging) and epidemiological criteria. During the survey, 95 (5.8%) patients with AE were identified and clinically confirmed; 91 agreed to further evaluation for NCC and 44 (48.3%) of them fulfilled either definitive or probable diagnostic criteria for NCC. These 44 patients belonged to 37 households. Epilepsy in the family and no separate place for keeping pigs were identified as risk factors for NCC clustering in a family. The study shows a very high prevalence of AE in the pig farming community and NCC as its major cause. Since NCC is a preventable and potentially eradicable disease, appropriate intervention strategies may help to reduce the disease burden.

In Vivo Demonstration of Neuroinflammatory Molecule Expression in Brain Abscess with Diffusion Tensor Imaging

BACKGROUND AND PURPOSE: Neuroinflammatory molecules, including tumor necrosis factor-α, interleukin1-β, lymphocyte function associated molecule-1, and intercellular cell adhesion molecule-1 contribute to the development of brain abscess. We hypothesized that the high fractional anisotropy (FA) in the brain abscess cavity reflects the upregulation of these neuroinflammatory molecules. Materials and METHODS: Diffusion tensor imaging (DTI) was performed in 24 patients with brain abscess and Staphylococcus aureus–treated as well as nontreated Jurket cell lines (at 4 time points: 1, 24, 48, and 72 hours). Neuroinflammatory molecules were quantified from the brain abscess cavity aspirate of the patients as well as from the heat-killed S aureus–treated and nontreated cell lines and correlated with DTI measures. RESULTS: The DTI-derived FA strongly correlated with the presence of neuroinflammatory molecules in the pus as well as in S aureus–treated cell lines; no such correlation was observed in nontreated cell lines. CONCLUSIONS: These data indicate that neuroinflammatory molecules confer high diffusion anisotropy inside the brain abscess cavity. We propose that increased FA reflects upregulated inflammatory response in brain abscess.

Role of diffusion tensor imaging metrics and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of cystic intracranial mass lesions.

The purpose of this study was to determine whether proton magnetic resonance spectroscopy (PMRS) and diffusion tensor imaging (DTI) indices, fractional anisotropy (FA) and mean diffusivity (MD) can be used to distinguish brain abscess from cystic brain tumors, which are difficult to distinguish by conventional magnetic resonance imaging (MRI). Fifty-three patients with intracranial cystic mass lesions and 10 normal controls were studied. Conventional MRI, PMRS and DTI of all the patients were performed on a 1.5-T GE scanner. Forty patients were with brain abscess and 13 with cystic tumors. Cytosolic amino acids (AAs) were present in 32 of 40 brain abscess patients. Out of 13 patients with cystic tumors, lactate and choline were seen in 3 and only lactate was present in 10 patients on PMRS. All 40 cases of abscess had high FA, while all 13 cases of tumor cysts had high MD values. We conclude that FA measurements are more sensitive in predicting the abscess, while PMRS and MD are more specific in differentiating abscess from cystic tumors. We suggest that PMRS should be combined with DTI rather than with diffusion-weighted imaging as FA can be used as an additional parameter for separation of abscess from other cystic intracranial mass lesions.

In vivo1H magnetic resonance spectroscopy-derived metabolite variations between acute-on-chronic liver failure and acute liver failure

Background and Aims: Acute‐on‐chronic liver failure (ACLF), acute liver failure (ALF) and chronic liver disease (CLD) are common forms of liver failure and present with similar clinical profiles. The aim of this study was to compare brain metabolite alterations in all the three groups of patients with controls, using in vivo proton magnetic resonance spectroscopy (MRS), and to look for any significant differences in metabolites that may help in differentiating between these three conditions.

Correlation of CSF neuroinflammatory molecules with leptomeningeal cortical subcortical white matter fractional anisotropy in neonatal meningitis.

It has been previously hypothesized that the high fractional anisotropy (FA) values in leptomeningeal cortical subcortical white matter (LCSWM) regions of neonatal brain with bacterial meningitis is due to the presence of adhesion molecules in the subarachnoid space, which are responsible for adherence of inflammatory cells over the subarachnoid membrane. The aim of this study was to look for any relationship between FA values in LCSWM regions and various neuroinflammatory molecules (NMs) in cerebrospinal fluid (CSF) measured in neonates with bacterial meningitis. Diffusion tensor imaging was performed on 18 term neonates (median age, 10.5 days) having bacterial meningitis and 10 age-/sex-matched healthy controls. CSF enzyme-linked immunosorbent assay was performed to quantify NMs [soluble intracellular adhesion molecules (sICAM), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta)]. Significantly increased FA values were observed in LCSWM regions of the patients compared to controls. A significant positive correlation was observed between FA values in LCSWM regions and NMs [sICAM (r=0.67, P=.006), TNF-alpha (r=0.69, P=.005) and IL-1beta (r=0.82, P=.000)] in CSF of these patients. No difference in FA values (P=.99) in LCSWM regions was observed between patients with sterile (0.12+/-0.02) and culture-positive CSF study (0.12+/-0.02). FA may be used as noninvasive surrogate marker of NMs in neonatal meningitis in assessing therapeutic response in future.

Clinical Implications of Increased Fractional Anisotropy in Meningitis Associated With Brain Abscess

Aim: To look for the clinical implications of increased cortical fractional anisotropy (FA) in meningitis patients associated with brain abscess. Material and Methods: Diffusion tensor imaging was performed in 10 patients of meningitis associated with brain abscess and 10 controls. The region of interest analysis was performed to calculate FA and mean diffusivity values from the abscess cavity and cortical regions of patients (enhancing and nonenhancing meninges on postcontrast T1-weighted images) and controls. Results: Significantly increased FA values with no change in mean diffusivity values were found in enhancing (FA = 0.113 ± 0.023, P = 0.000) as well as nonenhancing (FA = 0.085 ± 0.009, P = 0.000) cortical region of patients compared with controls (FA = 0.067 ± 0.010). Conclusions: Increased FA values in the enhancing as well as nonenhancing cortical regions suggest diffuse inflammatory activity in the pia-arachnoid in meningitis patients. It also suggests that FA may be a better indicator of active and diffuse meningeal inflammation than postcontrast T1-weighted images.

Assessment of therapeutic response in patients with brain abscess using diffusion tensor imaging.

BACKGROUND Accurate assessment of therapeutic response in patients with brain abscess (BA) is essential to direct appropriate therapy. This study was performed with an aim to see the treatment-induced changes in diffusion tensor imaging (DTI) indices (i.e., fractional anisotropy [FA] and mean diffusivity [MD]) in follow-up patients with BA after treatment. METHODS Twenty patients with BA were prospectively studied in this study. Diffusion tensor imaging in first follow-up was done in all after 1 week and in 6 at 4 weeks of the initial study. RESULTS The mean FA and MD values in first, second, and third studies were 0.28 +/- 0.03 and (0.81 +/- 0.07) x 10(-3) mm(2)/s, 0.18 +/- 0.09 and (1.08 +/- 0.09) x 10(-3) mm(2)/s, and 0.13 +/- 0.04 and (0.99 +/- 0.13) x 10(-3) mm(2)/s, respectively. The FA value was significantly (P < .01) decreased along with no significant change in MD value (P = .08) for 3 study periods. The mean volume (in milliliter) of the abscesses was 2.14 +/- 1.04, 1.34 +/- 0.45, and 0.77 +/- 0.14 in first, second, and third studies, respectively. CONCLUSIONS We conclude that the reduction in FA value reflects the down-regulation of the neuroinflammatory molecules in response to treatment in patient with BA and may be used to assess therapeutic response in these patients in future.