Prognostic role of D-dimer level upon admission in patients with traumatic brain injury

BACKGROUND

The aim of this study was to evaluate the prognostic role of D-dimer level upon admission in patients with traumatic brain injury (TBI) through performing a meta-analysis.

METHODS

PubMed, Web of Science, Cochrane Library, and EMBASE were searched for potential eligible literature. The study characteristics and relevant data were extracted. Poor functional outcome was defined according to the Glasgow Outcome Scale (GOS ≤3). Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled to estimate the predictive value of D-dimer for progressive hemorrhagic injury (PHI) and poor functional outcome at 3 months (3M GOS ≤3) in patients with TBI.

RESULTS

Eleven studies with 2761 patients were included. Eight studies examined the predictive role of higher D-dimer level for the risk of PHI, and the pooled OR was 1.72 (95% CI, 1.23-2.42). Three studies examined the predictive role of higher D-dimer level for the risk of 3M GOS ≤3, and the pooled OR was 2.00 (95% CI, 0.87-4.59). Significant between-study heterogeneities were observed, and sensitivity analyses and subgroup analyses were performed. No significant publication bias was found.

CONCLUSIONS

In conclusion, in patients with TBI, higher D-dimer level upon admission was associated with higher risk of PHI, yet no significant relationship was found between D-dimer level and the risk of 3M GOS ≤3. In the future, this readily available marker could help identify patients at risk and tailor management of these patients, thus reducing PHI and improving outcome.

Cerebrovascular resistance in patients with severe combined traumatic brain injury

Cerebrovascular resistance is an important parameter of the microcirculation. The main objective of cerebrovascular resistance is to maintain the constancy of cerebral blood flow and protect downstream vessels when changing perfusion pressure. The purpose of the study was to assess cerebrovascular resistance (CVR) in patients with severe combined traumatic brain injury (CTBI) with and without intracranial hematomas (IHs).

MATERIAL AND METHODS

We analyzed treatment outcomes in 70 patients with severe CTBI (42 males and 28 females). The mean age was 35.5 ± 14.8 years (min 15 years; max 73 years). All patients were divided into 2 groups, depending on the presence of intracranial hemorrhage. The first group included 34 patients without IH, and the second group included 36 patients with epidural (6), subdural (26), and multiple (4) hematomas. The GCS score was 10.4 ± 2.6 in the first group and 10.6 ± 2.8 in the second group. The ISS severity injury score was 32 ± 8 in the first group and 31 ± 11 in the second group. All patients were operated on within the first 3 days, with 30 (83.3%) patients being operated on during the first day. Perfusion computed tomography (PCT) of the brain was performed within 1-14 days after TBI in the first group and within 2-8 days after surgical evacuation of hematoma in the second group. After PCT, the mean arterial pressure was measured, and the blood flow rate in the middle cerebral artery was determined using transcranial dopplerography. Cerebrovascular resistance was calculated using the formula modificated by P. Scheinberg. Comparisons between the groups were performed using the Student t-test and χ² criterion.

RESULTS

The mean CVR values in each group (both with and without hematomas) were statistically significantly higher than the mean normal value of this parameter. Intergroup comparison of CVR values demonstrated a statistically significant increase in the CVR level in group 2 on the side of removed hematoma compared to group 1 (p=0.037). CVR in the perifocal zone of removed hematoma remained significantly higher compared to the symmetrical zone of the contralateral hemisphere (p=0.0009).

CONCLUSION

Cerebrovascular resistance in patients with combined traumatic brain injury is significantly increased compared to the normal value. Cerebrovascular resistance in the perifocal zone after evacuation of hematoma in patients with multiple injury remains significantly increased compared to the symmetrical zone in the contralateral hemisphere.

Haematoma of the tentorium cerebelli - new pathology or new prognostic factor in neurotraumatology? A preliminary report

BACKGROUND AND PURPOSE

The aim of the study was to establish the frequency of haematoma of the tentorium cerebelli, to elucidate the possible pathomechanism related to its formation, and to assess its clinical significance.

MATERIAL AND METHODS

84 patients with haematoma of the tentorium cerebelli were selected out of the 1159 patients treated in our Department from 2003 to 2005 due to craniocerebral trauma. All patients had computed tomography (CT) performed on admission. In selected cases, magnetic resonance imaging (MRI) was performed. Additionally, 4 autopsies were performed using a special technique for better recognition of blood location within the region of the tentorium.

RESULTS

The study group comprised 61 men (73%) and 23 women (age range: 18-84 years). Fall on the occiput was the main cause of trauma. The clinical status of patients was rather serious (53% of patients scored below 8 pts on the Glasgow Coma Scale on admission), as was the clinical course (39% of patients eventually died). The following co-existing pathologies were found in CT: traumatic subarachnoid haemorrhage and cerebral contusion (60% of patients), subdural haematoma (45%), intracerebral haematoma (31%), pathology in posterior fossa (12%), and epidural haematoma (8%). MRI revealed subdural collection of blood above or below the tentorium or the subarachnoid haemorrhage beneath the occipital lobes and/or over the cerebellar hemisphere.

CONCLUSIONS

The progress in neuroimaging, especially in CT scanning, enables haematoma of the tentorium cerebelli to be discerned as a distinct clinical entity.

Brain abscess following intracerebral haemorrhage

We report two cases of brain abscess, which developed at the site of an intracerebral haemorrhage (ICH) in a 75-year-old man and a 32-year-old-man. The patients recovered after surgical treatment and systemic antibiotic therapy. The route of infection could not be detected in either case. The literature contains only 13 reported cases of brain abscess as a complication of ICH. Although the interval from initial ICH to abscess formation ranged from 4 to 20 weeks, almost all patients had episodes of high fever, indicating the presence of systemic infection and bacterial seeding, 0-14 days after the onset of their ICH. Therefore, abscess formation appears to be caused by haematogenous seeding of infection in patients with ICH. Abscess formation should be considered when a patient deteriorates clinically with a febrile episode after an ICH.

Cerebellar haemorrhage after non-traumatic evacuation of supratentorial chronic subdural haematoma: report of two cases

Cerebellar haemorrhage is an unusual complication of supratentorial neurosurgery. Several causative pre-operative factors and medical risk factors may predispose patients to cerebellar haemorrhage, however its etiology remains still unclear. Only two case reports have previously described the occurrence of cerebellar haemorrhage after subdural haematoma evacuation by burr-hole trepanation. We present two patients with this rare postoperative complication of minor supratentorial neurosurgery and possible underlying pathophysiological mechanisms are discussed. Our two cases support the post- rather than per-operative pathogenetic hypothesis. Although the complication is associated with a significant morbidity and mortality, most cases follow a benign course.

The pathophysiology of traumatic brain injury in α7 nicotinic cholinergic receptor knockout mice

The alpha7 nicotinic cholinergic receptor is a ligand-gated ion channel with calcium permeability similar to that of ionotrophic glutamate receptors. Previous studies from our laboratory have implicated changes in expression alpha7 nicotinic cholinergic receptors in the pathophysiology of traumatic brain injury (TBI). In rats, TBI causes a time-dependent and significant decrease in cortical and hippocampal alpha-[(125)I]-bungarotoxin (BTX) binding. We have postulated that deficits in alpha7 expression may contribute to TBI-induced cognitive impairment and that nicotinic receptor agonists can reverse alpha7 binding deficits and result in significant cognitive improvement compared to saline-treated controls. Thus, alpha7 nAChRs could be involved in a form of cholinergically mediated excitotoxicity following brain injury. In the current study, wild-type, heterozygous and null mutant mice were employed to test the hypothesis that genotypic depletion of the alpha7 receptor would render animals less sensitive to tissue loss and brain inflammation following experimental brain injury. Mice were anesthetized and subjected to a 0.5-mm cortical contusion injury of the somatosensory cortex. Brain inflammation, changes in nicotinic receptor expression and cortical tissue sparing were evaluated in wild-type, heterozygous and homozygous mice 1 week following TBI. In wild-type mice, brain injury caused a significant decrease in BTX binding in several hippocampal regions, consistent with what we have measured in rat brain following TBI. However, there were no genotypic differences in cortical tissue sparing or brain inflammation in this experiment. Although the results of this study were largely negative, it is still plausible that changes in the activity/expression of native alpha7 receptors contribute to pathophysiology following TBI. However, when null mutant mice develop in the absence of central alpha7 expression, it is possible that compensatory changes occur that confound the results obtained.

IL-1RN and IL-1B gene polymorphisms and cerebral hemorrhagic events after traumatic brain injury

OBJECTIVE

To investigate the association of (variable number tandem repeat) interleukin (IL) 1RN and (-511) IL-1B gene polymorphisms with brain hemorrhagic events after traumatic brain injury (TBI).

METHODS

Data from brain CT, Glasgow Coma Scale (GCS) at admission, and 6-month Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) were collected for 151 prospectively recruited patients with TBI. IL-1RN and IL-1B genotypes were determined using standard methods. Presence vs absence of any type of brain hemorrhage was the main outcome. Type of brain hemorrhage, GCS at admission, and 6-month GOS and mRS were secondary outcomes. Odd ratios (ORs) and corresponding 95% CI were calculated using logistic regression analyses. In adjusted models, the associations were controlled for age, gender, diffuse brain edema, volume of intracranial hematoma, neurosurgical intervention, and GCS at admission. p values less than 0.01 were considered significant.

RESULTS

Compared with noncarriers, IL-1RN allele 2 carriers had higher odds of having cerebral hemorrhages after TBI (adjusted OR = 4.57; 95% CI = 1.67 to 12.96; p = 0.004). The associations for (-511) IL-1B polymorphism were not significant.

CONCLUSION

There is an association between the presence of interleukin-1RN allele 2 and posttraumatic brain hemorrhage.

Trauma modulates amygdala and medial prefrontal responses to consciously attended fear

Effective fear processing relies on the amygdala and medial prefrontal cortex (MPFC). Post-trauma reactions provide a compelling model for examining how the heightened experience of fear impacts these systems. Post-traumatic stress disorder (PTSD) has been associated with excessive amygdala and a lack of MPFC activity in response to nonconscious facial signals of fear, but responses to consciously processed facial fear stimuli have not been examined. We used functional MRI to elucidate the effect of trauma reactions on amygdala-MPFC function during an overt fear perception task. Subjects with PTSD (n = 13) and matched non-traumatized healthy subjects (n = 13) viewed 15 blocks of eight fearful face stimuli alternating pseudorandomly with 15 blocks of neutral faces (stimulus duration 500 ms; ISI 767 ms). We used random effects analyses in SPM2 to examine within- and between-group differences in the MPFC and amygdala search regions of interest. Time series data were used to examine amygdala-MPFC associations and changes across the first (Early) versus second (Late) phases of the experiment. Relative to non-traumatized subjects, PTSD subjects showed a marked bilateral reduction in MPFC activity (in particular, right anterior cingulate cortex, ACC), which showed a different Early-Late pattern to non-traumatized subjects and was more pronounced with greater trauma impact and symptomatology. PTSD subjects also showed a small but significant enhancement in left amygdala activity, most apparent during the Late phase, but reduction in Early right amygdala response. Over the time course, trauma was related to a distinct pattern of ACC and amygdala connections. The findings suggest that major life trauma may disrupt the normal pattern of medial prefrontal and amygdala regulation.

Pathophysiology of posttraumatic temporal lobe lesions

BACKGROUND

Posttraumatic parenchymal lesions in the temporal lobe may cause neurologic deterioration. An analysis was made of the natural evolution of this type of lesion, with emphasis on its 2 components: hemorrhage (hyperdense on computed tomography [CT]), and edema and necrosis (hypodense on CT). The clinical repercussions were studied, and the factors that might influence such evolution were investigated.

METHODS

Forty head-injured patients with temporal lobe lesions admitted within 12 hours after the injury were selected in a prospective manner. Computed tomography scans were systematically repeated within the first 36 hours and at 7 and 30 days postinjury. Factors such as interval between injury and the first CT scan, age, velocity of the injury, alcohol consumption, coagulation abnormalities, and the presence of decompressive measures were compared between the patients that had enlargement of the hemorrhage and those who did not. Increase in hypodensity was compared with that in hyperdensity.

RESULTS

Fourteen patients showed enlargement of the hemorrhage. In all cases but one, the interval between injury and admission was 3 hours or less. Other factors had no statistical significance as predisposing causes for such enlargement. In approximately half of the cases, the hypodense component increased in the first 36 hours and continued increasing until the end of the first week. Evolution of the hypodense component was not dependent on behavior of the hemorrhage, surgical drainage, or diameter of the hemorrhagic lesion.

CONCLUSIONS

The natural evolution of the hyperdense component of temporal lobe lesions was to enlarge within the first few hours after the injury. Edema and necrosis developed more slowly and with no significant clinical manifestations.

The localization of central pattern generators for swallowing in humans — a clinical-anatomical study on patients with unilateral paresis of the vagal nerve, Avellis’ syndrome, Wallenberg’s syndrome, posterior fossa tumours and cerebellar hemorrhage

BACKGROUND

Our understanding of brainstem swallowing centers is mainly based on experimental animals. In order to solve this problem also in humans, a clinical-anatomical study on dysphagic patients with different lesion patterns was performed.

PATIENTS AND METHODS

We studied 43 consecutively admitted dysphagic patients with unilateral paresis of the vagal nerve (PVN), Avellis' syndrome (AS), Wallenberg's syndrome (WS), posterior fossa tumour (PFT) or cerebellar hemorrhage (CH) with regard to clinical and anatomical aspects.

FINDINGS

There was a continuum with regard to functional outcome from neurogenic dysphagia (ND): Patients with PFT or CH had a significantly worse outcome than patients with WS; the outcome of WS patients was significantly worse than that of patients with PVN or AS. In AS only the Nucleus ambiguus (NA) and its surrounding reticular formation (RF) were affected. In all patients with WS, the infarctions of the dorsolateral medulla were situated in the rostral third of the medulla and affected the NA and the Nucleus tractus solitarii (NTS) with their surrounding RF. In patients with PFT and CH, the NTS and its surrounding RF were affected on both sides. The overlap area of WS and PFT lesions is situated in the NTS and the surrounding RF, especially in its Nucleus parvocellularis.

INTERPRETATION

Our results point to the fact, that in humans the dorsomedial central pattern generators (CPGs) for swallowing are situated in the rostral part of the dorsal medulla oblongata near the NTS/surrounding RF (especially Nucleus parvocellularis) and that the dorsomedial CPGs are superior to the ventrolateral CPGs (near the NA/surrounding RF) with regard to their swallowing-relevance. Furthermore, we hypothesize that due to the individual asymmetry of the swallowing-dominant forebrain hemisphere - the outcome from ND in WS depends on the side of the medullary infarction.

Mixed dishomogeneous hemorrhagic brain contusions. Mapping of cerebral blood flow

The aim of the study was to verify whether regional cerebral blood flow (rCBF) was distributed centrifugally in traumatic hemorrhagic contusions with multiple cores within an oedematous area. Seventeen traumatic brain contusions, from 14 patients with severe head injury (GCS < 9), were analyzed during 39 Xenon-enhanced computerized tomography (Xe-CT) studies. The CBF was measured in 3 concentric regions of interest (ROls): the hemorrhagic core, the intracontusional oedematous low density area and a 1 cm rim of pericontusional normal-appearing brain tissue surrounding the contusion. Differences between rCBFs in the three ROIs were found (p < 0.0001). rCBF in both the hemorrhagic core (21.4 +/- 19.4 ml/ 100gr/min) and the intracontusional low density area (28.4 +/- 19 ml/100gr/min) were lower than rCBF in pericontusional normal-appearing area (41.9 +/- 16 ml/100gr/min) (p < 0.0001). No significant differences were found between rCBF measured in the hemorrhagic core and intracontusional low density area (p = 0.184). Our study suggests that in the mixed density contusions with multiple hemorrhagic cores, the CBF is concentrically distributed, improving from the core to the periphery.

Cutaneous stimulation improves function of a chronic patient with cerebellar damage

The prognosis of cerebellar hemorrhage with brain stem compression is known to be poor, and patients who can usually survive are severely disabled with limited benefit from conventional rehabilitation. An innovative cutaneous stimulation was administered to a chronic patient (2 years after the incidence) who has severe ataxia, gait imbalance and limb spasticity caused by cerebellar hemorrhage. After 8 months of intervention, patient's function as evaluated by two functional measures has improved by 40%. In addition, the patient's ataxia and hypotonia have improved significantly in which he has regained the abilities to grasp objects, sit upright, control his equilibrium, and monitor an electric wheelchair. The present case study demonstrated a significant improvement of a chronic severely disabled patient who received the intervention 2 years after the accident, suggesting that the cutaneous stimulation may be a possible effective neurologic intervention.

Time course of cortical hemorrhages after closed traumatic brain injury: statistical analysis of posttraumatic histomorphological alterations

We examined 305 autopsied brains for histomorphological alterations to determine the time course of reactions in cortical hemorrhages following traumatic closed brain injury. Eighteen morphological criteria were considered: red blood cells (RBCs), polymorphonuclear leukocytes (PMNs), macrophages (Ms), RBC-containing Ms, hemosiderin, hematoidin, lipid-containing Ms, fibroblasts, endothelial cells, collagenous fibres, gemistocytic astrocytes, fibrillary gliosis, hemosiderin-containing astrocytes, neuronal damage, neuronophagy, axonal swelling (beta-amyloid precursor protein: beta-APP), axonal bulbs (van Gieson stain), and mineralisation of neurons. The interval between the time of brain injury and death ranged from 1 min to 58 years. Following routine staining and immunohistochemical staining of microglia (CD68), astrocytes (GFAP) and injured axons (beta-APP), paraffin sections were examined by light microscopy for the presence of the selected histomorphological features. For each cytomorphological phenomenon, the time at which it could be demonstrated for the first time and for the last time (observation period) was determined. The relative frequency of each criterion was established for each observation period. The limits of confidence for the respective relative frequencies were estimated with a reliability of 95% according to Clopper and Pearson. An apparent correlation was found between the frequency of a given histomorphological phenomenon and the length of the posttraumatic interval. To check for accuracy of prediction, half of the cases (group 1; n = 153) were used to develop a multistage evaluation model; half (group 2; n = 152) were used to evaluate the validity of the data of group 1. Applying this model, 117 of the 152 control group cases (76.97%) could be correctly classified and further 26 cases (17.11%) being assigned to an interval close to the correct interval. Thus, this model allows classification of the correct posttraumatic interval or an interval close to the correct posttraumatic interval in about 95% of cases. We developed a software program that allows the estimation of survival time of TBI based on the relative frequency of the 18 morphological features. Applying this software will help to estimate the posttraumatic interval of cortical hemorrhages following TBI of unknown survival time.

Prognostic factors in the occurrence of posttraumatic epilepsy after penetrating head injury suffered during military service

In this retrospective study, the authors evaluated confounding risk factors, which are allegedly influential in causing unprovoked posttraumatic epilepsy, in 489 patients from the frontlines of the Iran–Iraq War.

Four hundred eighty-nine patients were followed for 6 to154 months (mean 39.4 months, median 23 months), and important factors precipitating posttraumatic epilepsy were evaluated using uni- and multivariate regression analysis.

One hundred fifty-seven (32%) of 489 patients became epileptic during the study period. The results of univariate analysis indicated a significant relationship between epilepsy and Glasgow Outcome Scale (GOS) score (X2 = 76.49, p < 0.0001, df = 2), Glasgow Coma Scale score at admission (X2 = 19.48, p < 0.0001, df = 3), motor deficit (X2 = 11.79, p < 0.001, df = 1), mode of injury (X2 = 10.731, p < 0.05), transventricular injury (X2 = 6.9, p < 0.008, df = 1), dysphasia (X2 = 5.3, p < 0.02), central nervous system infections (X2 = 5.3, p < 0.02), and early-onset seizures (X2 = 4.1, p < 0.04, df = 1). The results of multivariate analysis, on the other hand, indicated that the GOS score and motor deficit were of greater statistical importance (X2 = 35.24, p < 0.0001; and X2 = 7.1, p < 0.07, respectively). Factors that did have much statistically significant bearing on posttraumatic epilepsy were the projectile type, site of injury on the skull, patient age, number of affected lobes, related hemorrhagic complications, and retained metallic or bone fragments.

Glasgow Outcome Scale score and focal motor neurological deficit are of particular importance in predicting posttraumatic epilepsy after missile head injury.

Traumatic intracranial aneurysms

Traumatic intracranial aneurysms are rare, occurring in fewer than 1% of patients with cerebral aneurysms. They can occur following blunt or penetrating head trauma and are more common in the pediatric population. Traumatic aneurysms can be categorized histologically as true, false, or mixed, with false aneurysms being the most common. These aneurysms can present in a variety of ways, but are typically associated with an acute episode of delayed intracranial hemorrhage with an average time from initial trauma to aneurysm hemorrhage of approximately 21 days. The mortality rate for patients harboring these aneurysms may be as high as 50%. Prompt diagnosis based on arteriography and aggressive surgical management are associated with better outcome than conservative treatment. The authors describe a classification scheme for traumatic aneurysms based on their anatomical location and conclude that 1) post-traumatic aneurysm must be considered in patients with acute neurological deterioration following closed head injury; 2) they can occur following mild closed head injury; 3) they occur more commonly in children than in adults; and 4) surgical clipping and/or endovascular occlusion is the definitive treatment.