Nupur Pruthi

Characterization of traumatic brain injury in human brains reveals distinct cellular and molecular changes in contusion and pericontusion

Traumatic brain injury (TBI) contributes to fatalities and neurological disabilities worldwide. While primary injury causes immediate damage, secondary events contribute to long‐term neurological defects. Contusions (Ct) are primary injuries correlated with poor clinical prognosis, and can expand leading to delayed neurological deterioration. Pericontusion (PC) (penumbra), the region surrounding Ct, can also expand with edema, increased intracranial pressure, ischemia, and poor clinical outcome. Analysis of Ct and PC can therefore assist in understanding the pathobiology of TBI and its management. This study on human TBI brains noted extensive neuronal, astroglial and inflammatory changes, alterations in mitochondrial, synaptic and oxidative markers, and associated proteomic profile, with distinct differences in Ct and PC. While Ct displayed petechial hemorrhages, thrombosis, inflammation, neuronal pyknosis, and astrogliosis, PC revealed edema, vacuolation of neuropil, axonal loss, and dystrophic changes. Proteomic analysis demonstrated altered immune response, synaptic, and mitochondrial dysfunction, among others, in Ct, while PC displayed altered regulation of neurogenesis and cytoskeletal architecture, among others. TBI brains displayed oxidative damage, glutathione depletion, mitochondrial dysfunction, and loss of synaptic proteins, with these changes being more profound in Ct. We suggest that analysis of markers specific to Ct and PC may be valuable in the evaluation of TBI pathobiology and therapeutics. We have characterized the primary injury in human traumatic brain injury (TBI). Contusions (Ct) – the injury core displayed hemorrhages, inflammation, and astrogliosis, while the surrounding pericontusion (PC) revealed edema, vacuolation, microglial activation, axonal loss, and dystrophy. Proteomic analysis demonstrated altered immune response, synaptic and mitochondrial dysfunction in Ct, and altered regulation of neurogenesis and cytoskeletal architecture in PC. Ct displayed more oxidative damage, mitochondrial, and synaptic dysfunction compared to PC.

Apolipoprotein E polymorphism and outcome after mild to moderate traumatic brain injury: A study of patient population in India

BACKGROUND The nature and extent of recovery after traumatic brain injury (TBI) is heterogeneous. Apolipoprotein E (APOE) plays a major role in repair of cell membrane and growth of neurites following injury to cells. Studies done on the western population have shown that the APOE e4 genotype is associated with poor survival following neurotrauma. AIM To explore the association of APOE polymorphism and outcome following TBI in a patient population from a tertiary care hospital exclusive for neurological diseases in south India. PATIENTS AND METHODS Ninety eight patients who sustained mild to moderate TBI (computed tomography (CT) scan brain showing traumatic parenchymal contusions) were the subjects of the study and the study period was from November 2003 to December 2008. APOE polymorphism status was determined by PCR technique using venous blood. Patients were assessed on follow-up with a battery of four neuropsychological tests as well as Glasgow outcome scale. RESULTS Of the 98 patients, 20 (20%) patients had at least one APOE e4 allele. A follow-up of minimum six months was available for 73 patients. None of the 12 patients who had at least one APOE e4 allele had a poor outcome at six-month follow-up whereas 11(18%) patients without an APOE e4 allele had a poor outcome (Fishers Exact test, P=0.192). On the neuropsychological tests, performance of patients with APOE e4 allele did not differ significantly from those without these alleles. CONCLUSION This study does not support the current contention that the presence of APOE e4 allele should have a significant negative effect on the outcome after TBI.

Glutathione metabolism is modulated by postmortem interval, gender difference and agonal state in postmortem human brains

The equilibrium between antioxidant function and oxidative stress is implicated in brain pathology. However, human studies on oxidant and antioxidant markers rely on postmortem tissue that might be affected by pre and postmortem factors. To evaluate the effect of these variables, we tested whether antioxidant enzymes [superoxide dismutase (SOD), catalase] glutathione (GSH) and related enzymes [gamma glutamylcysteine ligase (GCL), GSH peroxidase (GPx), GSH reductase (GR), GSH-S-transferase (GST)] and malondialdehyde (MDA, marker of lipid peroxidation) are affected in postmortem human brains (n=50) by increase in postmortem interval (2.5-26 h), gender difference and agonal state [based on Glasgow coma scale (GCS): range: 3-15] in different anatomical regions-frontal cortex (FC), cerebellum (CB) medulla oblongata (MO), substantia nigra (SN) and hippocampus (HC). While SOD and catalase activities were relatively unaltered, GR and GPx activities were affected by agonal state (GR in CB, p<0.05; GPx in MO, p<0.05) indicating altered GSH dynamics during the secondary events following neuronal injury. MO, SN and HC displayed low GSH compared to FC and CB. Total GSH level was decreased with PMI (MO, p=0.02) which could be partly attributed to increase in MDA levels with increasing PMI in MO (p<0.05). Total GSH level was higher in CB (p<0.017) and MO (p<0.04) in female brains compared to males. Interestingly, HC and SN regions showed significant stability in most of the markers tested. We suggest that while SOD and catalase were relatively unaffected by the pre and postmortem factors, GSH and its metabolic enzymes were significantly altered and this was more pronounced in MO of postmortem human brains. These data highlight the influence of pre and postmortem factors on GSH dynamics and the inherent differences in brain regions, with implications for studies on brain pathophysiology employing human samples.

Mitochondrial function in human brains is affected by pre- and post mortem factors

G. Harish, C. Venkateshappa, A. Mahadevan, N. Pruthi, M. M. S. Bharath and S. K. Shankar (2013) Neuropathology and Applied Neurobiology39, 298–315

Effect of Storage Time, Postmortem Interval, Agonal State, and Gender on the Postmortem Preservation of Glial Fibrillary Acidic Protein and Oxidatively Damaged Proteins in Human Brains

Biochemical analyses of many brain diseases have highlighted that oxidative damage of proteins and astrogliosis are important events associated with pathology. However, human studies on the status of protein oxidation/nitration and astrogliosis [indicated by expression of glial fibrillary acidic protein (GFAP)] heavily depend on postmortem tissues that might be altered by pre and postmortem factors. To evaluate the effect of these variables, we tested whether the status of GFAP expression, oxidized proteins, and nitrated proteins (by protein 3-nitrotyrosine or 3-NT) were affected in postmortem human brains (n=48) by increased storage time (11.8-104.1 months), postmortem interval (PMI) (2.5-26 h), gender difference, and agonal state (based on Glasgow coma scale: range: 3-15) in different anatomical regions-frontal cortex (FC), cerebellum (CB) and medulla oblongata (MD). We observed that increasing storage time significantly decreased the stability of all 3 markers in MD (oxyblot: P=0.003; 3-NT: P=0.01; GFAP: P=0.03) and that of oxidized proteins in CB (P=0.04), whereas the status of all markers was not significantly altered in FC. On the other hand, PMI and agonal state did not influence the status of all the markers tested in any of the regions. Similarly, except for the decreased protein 3-NT among women in CB compared with men (P=0.04), there was no effect due to gender differences in other brain regions for other markers. These data highlight the influence of storage time on preservation of markers of protein damage and astrogliosis and the inherent differences in brain regions, with implications for studies on brain pathology employing stored human samples.

Mixed-density extradural hematomas on computed tomography-prognostic significance

BACKGROUND It has been variably reported that patients who acutely present with low- or mixed-density blood on CT scan are associated with poor clinical outcome. The aim of the study was to correlate the presence or absence of mixed density within EDHs on CT scanning with the clinical outcome. METHODS This is a retrospective study of a total of 109 patients with EDHs who were operated on from August 2001 to August 2002. The CT scans were reviewed and classified into 2 categories-predominantly hyperdense and mixed density. This was correlated with clinical details and outcome. RESULTS In all, 43.2% (16/37) of patients in the mixed-density category presented with GCS of no more than 8 as compared with 23.6% (17/72) of patients in the hyperdense group (P < .05). Mean hematoma volume in the mixed-density group was 72 cm(3) as compared with 42 cm(3) in the hyperdense group (P < .05). Mortality rate was significantly higher in the mixed-density category (21.6% vs 4.2%, P < .05). CONCLUSION The study portends mixed density in EDH as a potent poor prognostic indicator. The mixed density of the clot probably indicates that the clot is rapidly increasing in size and requires even earlier and more aggressive treatment.

Morphometric and radiological assessments of dimensions of Axis in dry vertebrae: A study in Indian population

Background: The technique of intralaminar screw placement for achieving axis (C2) fixation has been recently described. The purpose of the study was to provide the morphometric and radiological measurements in Indian population and to determine the feasibility of safe translaminar screw placement in this population. To the best of our knowledge there is no study (cadaveric or radiological) done in Indian population to detect suitability of axis bone for laminar screw fixation. Material and Methods: 38 dry axis vertebrae from adult South Indian population were subjected to morphometric measurement and CT scan analysis. Height of posterior arch, midlaminar width(bilateral) in upper 1/3rd, middle 1/3rd and lower 1/3rd were measured using high precision Vernier Calipers. Each vertebra was subjected to a spiral CT scan (Philips brilliance 16 slice) thin 0.5 mm slices were taken and reconstruction was done in coronal and sagittal plane. Analysis was done on a CT work station. Using axial slices, sagittal cuts were reconstructed in plane perpendicular to the lamina at the mid laminar point and upper-middle and lower 1/3rd width of the lamina measured. Height of the posterior arch was measured in the sagittal plane. Intralaminar angle was measured bilaterally. Results: Middle 1/3rd lamina was the thickest portion (mean 5.17 mm +/- 1.42 mm). A total of 32 (84.2%) specimen were having midlaminar width in both lamina greater than 4 mm, however only 27 (71%) out of them had spinous process more than 9 mm. CT scan measurement in middle and lower 1/3rd lamina was found to be strongly correlated with the direct measurement. Conclusion: There is high variability in the thickness of the C2 lamina. As compared to western population, the axis bones used in the present study had smaller profiles. Hence the safety margin for translaminar screw insertion is low.

Patterns of head injury among drivers and pillion riders of motorised two-wheeled vehicles in Bangalore

Abstract Pattern of injuries among pillion riders are not well studied. A limited number of studies do indicate that there is no significant difference in the severity of injuries sustained by pillion riders and drivers. Very few cities in India have mandatory helmet law for pillion riders. The aims of the present study were to study the pattern of head injuries in patients involved in two wheeler accidents and to compare injuries of drivers and pillion riders; drivers with and without helmet. Tw o hundred and four consecutive patients admitted under trauma unit of NIMHANS (102 pairs of drivers and pillion riders) were included in the study from April to mid-June 2009. In the second part, records of 116 patients who died in a two wheeler accident between July 2008 and July 2009 were retrieved from NIMHANS mortuary and retrospectively analysed. There was no significant difference between the GCS scores of drivers and pillion riders ( mild head injury - 60.8% Vs 74.5%, moderate head injury-32.3% Vs 22.5%, severe head injury- 6.9% Vs 2.9%). Both the groups also did not differ significantly with regards to CT scan findings. Only 44 drivers (43.1%) were wearing helmet at the time of injury. The postmortem study revealed that only 10/83 (12%) drivers were wearing helmet at the time of the fatal accident. To conclude, there is no significant difference between the head injuries sustained by the motorized two wheeler drivers and their pillion riders. Helmets must be made mandatory for pillion riders throughout the country.

Tubercular meningitis with hydrocephalus with HIV co-infection: role of cerebrospinal fluid diversion procedures

OBJECT Hydrocephalus is one of the commonest complications of tubercular meningitis (TBM), and its incidence is increasing with the HIV epidemic. Literature evaluating the role of ventriculoperitoneal shunts in HIV-positive patients with TBM and their long-term prognosis is scarce. METHODS Between June 2002 and October 2012, 30 HIV-positive patients with TBM and hydrocephalus underwent ventriculoperitoneal shunt placement. Thirty age-, sex-, and grade-matched HIV-negative patients with TBM and hydrocephalus were randomly selected as the control group. Outcome was analyzed at discharge (short-term outcome) and at follow-up (long-term outcome). Univariate and multivariate analyses were performed to look for predictors of outcome; p < 0.05 was considered significant. RESULTS There were no differences in the clinical, radiological, or biochemical parameters between the 2 groups. Short-term outcome was better in the HIV-negative group (76.7% improvement) than in the HIV-positive group (70%). However, the long-term outcome in HIV-positive patients was very poor (66.7% mortality and 76.2% poor outcome) compared with HIV-negative patients (30.8% mortality and 34.6% poor outcome). Seropositivity for HIV is an independent predictor of poor outcome both in univariate and multivariate analyses (p = 0.038). However, in contrast to previous reports, of 5 patients with TBM in good Palur grades among the HIV-positive patients, 4 (80%) had good outcome following shunt placement. CONCLUSIONS The authors recommend that shunt treatment should not be performed in HIV-positive patients in poor Palur grade with hydrocephalus. A trial of external ventricular drainage should be undertaken in such patients, and shunt treatment should be performed only if there is any improvement. However, HIV-positive patients in good Palur grades should undergo VP shunt placement, as these patients have better outcomes than previously reported.

Effect of Premortem and Postmortem Factors on the Distribution and Preservation of Antioxidant Activities in the Cytosol and Synaptosomes of Human Brains

The human brain displays oxidant and antioxidant markers with regional specificity that directly impinges on neuronal function in aging and in disease states. Similarly, the antioxidant activities might exhibit differential intracellular distribution rendering subcellular structures differentially vulnerable to toxic insults. To investigate the subcellular distribution of antioxidant activities in the human postmortem brain, we assayed superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) in the cytosol and synaptosomal fraction from the frontal cortex (FC) of 45 postmortem human brains. We also tested whether these activities were altered by premortem and postmortem factors, including increasing storage time (11.8-104.1 months), postmortem interval (PMI) (2.5-26 h), age and gender differences, and agonal state [based on Glasgow coma scale (GCS): range: 3-15]. Overall, the antioxidant activities were found to be several folds lower in the synaptosomes compared to cytosol, which could make it more susceptible to degeneration. The activities were significantly affected mainly by age (SOD increased in synaptosomes, p=0.01; GSH decreased in cytosol, p=0.03; GPx decreased in cytosol and increased in synaptosomes, p=0.05; GST decreased in synaptosomes, p=0.05) and to a lesser extent by other premortem (GST decreased with GCS in synaptosomes, p=0.02) and postmortem factors (GSH decreased with PMI in cytosol, p=0.04). Increasing storage time or gender difference did not affect the antioxidant activities. We infer that premortem and postmortem factors in general, and increasing age in particular, significantly alter the antioxidant activities in subcellular fractions of postmortem brain with implications for studies on brain pathology employing stored human samples.