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PubMed1999

Effects of bradykinin in the cerebral circulation.

All components of an intracerebral kallikrein-kinin system have been described. Thus, bradykinin (BK) acting from the parenchymal side as well as from the blood side may influence cerebral microcirculation. BK is a potent dilator of extra- and intraparenchymal cerebral arteries when acting from the perivascular side. The vasomotor effect of BK is mediated by B2 receptors which appear to be located at the abluminal membrane of the endothelial cell. Signal transmission from the endothelial to the smooth muscle cell is mediated by NO, prostanoids, free radicals or H2O2 depending on the animal species and on the location of the artery. Selective opening of the blood-brain barrier for small tracers (Na+-fluorescein: MW, 376) has been found in cats during cortical superfusion or intraarterial application of BK. This leakage is mediated by B2 receptors located at the luminal and abluminal membrane of the endothelial cells and probably mediated by an opening of tight junctions. Formation of brain edema has been found after ventriculo-cisternal perfusion or interstitial infusion of BK. This can be explained by increase of vascular permeability and cerebral blood flow due to arterial dilatation thus enhancing driving forces for the extravasation. An increase of the BK concentration in the interstitial space of the brain up to concentrations which induce extravasation, dilatation and edema formation has been found under several pathological conditions. Thus, BK may be involved in edema and necrosis formation after cold lesion, concussive brain injury, traumatic spinal cord and ischemic brain injury.

Animals↗
PubMed1975

Experimental brain damage from fluid pressures due to impact acceleration. 2. Pathophysiological observations.

The significance of the intracranial acceleration pressure pattern at impact to the intact skull in production of brain damage is discussed, particularly as regards the contre-coup pressures. A rigid fluid-filled cylinder was connected to the skull cavity of rabbits; the cylinder was impacted and the intracranial contents acted as a contre-coup end. The pressure pattern was also modified by injection of small quantified air volumes. The pathophysiological effects of "experimental brain concussion" with vasomotor and respiratory disturbances which occurred were related to the contre-coup pressures produced, particularly the magnitude of subatmospheric pressures and the duration of late positive pressures. Some implications on their significance for brain tissue flow are discussed.

Acceleration↗
PubMed2006

Bench to bedside: evidence for brain injury after concussion--looking beyond the computed tomography scan.

The emergency management of cerebral concussion typically centers on the decision to perform a head computed tomography (CT) scan, which only rarely detects hemorrhagic lesions requiring neurosurgery. The absence of hemorrhage on CT scan often is equated with a lack of brain injury. However, observational studies revealing poor long-term cognitive outcome after concussion suggest that brain injury may be present despite a normal CT scan. To explore this idea further, the authors reviewed the evidence for objective neurologic injury in humans after concussion, with particular emphasis on those with a normal brain CT. This evidence comes from studies involving brain tissue pathology, CT scanning, magnetic resonance image (MRI) scanning, serum biomarkers, formal cognitive and balance tests, functional MRI, positron emission tomography, and single-photon emission computed tomography scanning. Each section is accompanied by technical information to help the reader understand what these tests are, not to endorse their use clinically. The authors discuss the strengths and weaknesses of the evidence in each case. These reports make a compelling case for the existence of concussion as a clinically relevant disease with demonstrable neurologic pathology. Areas for future emergency medicine research are suggested.

Axons↗
PubMed2001

Beyond erythropoiesis: novel applications for recombinant human erythropoietin.

Erythropoietin (EPO) primarily is produced in the kidney and acts as a principal mediator of the physiologic response to hypoxia by increasing red blood cell production. Astrocytes and neurons in the central nervous system (CNS) also are known to produce EPO in response to hypoxia/ischemia. EPO appears to play a neuroprotective role based on preclinical data demonstrating the ability of recombinant human erythropoietin (r-HuEPO) to shield neurons from hypoxic/ischemic stress when administered intracerebraventricularly. In CNS models, systemically administered r-HuEPO has not been intensely investigated because large glycosylated molecules generally were deemed incapable of crossing the blood-brain barrier (BBB). A collaborative research effort identified expression of EPO receptors on human brain capillaries and a specific receptor-mediated transport of r-HuEPO across the BBB after a single intraperitoneal (IP) injection in rodents, with subsequent protection against various types of neuronal damage. For example, administration of r-HuEPO 24 hours before or up to 6 hours after focal ischemic stroke significantly reduced the extent of infarction. r-HuEPO also attenuated concussive brain injury, kainate-induced seizure activity, and autoimmune encephalomyelitis. These preclinical findings suggest that r-HuEPO may have therapeutic potential for stroke, head trauma, and epilepsy; additional studies are needed to confirm and extend these encouraging observations in animal models.

Animals↗
PubMedDate not supplied

Papillary glioneuronal tumor--a new tumor entity.

Glioneuronal neoplasms of the CNS comprises a heterogeneous group of generally low-grade tumors expressing glial and neuronal cells of varying differentiation. Recently, a new variant of the glioneuronal tumors has been identified. We present a case of a glioneuronal tumor located in the left frontal lobe of a 16-year-old boy who developed seizures 6 months after brain concussion. MR scan demonstrated an irregular, but well circumscribed, mixed cystic and solid tumor with contrast enhancement in the solid part. Histology showed a papillary glioneuronal tumor. The tumor is indolent with no sign of recurrence after gross total resection.

Adolescent↗
PubMed1989

[Early diagnosis of traumatic epilepsy].

The risk factors and clinical course of prodromal period were studied in 184 patients with traumatic epilepsy. Statistically reliable as predictors of traumatic epilepsy were: brain concussion++, open lesions of the skull, repeated craniocerebral trauma, comatose after-trauma states lasting over more than 6 hours, episodes of consciousness confusion, myoclonic spells. The establishment of the risk factors in the prodromal stage of posttraumatic epilepsy provides means for the early diagnose, secondary prevention and social-hygienic measures designing.

Adult↗
PubMedDate not supplied

[Problems in biomechanics of life-time intracranial injuries].

Discusses the impact of kinetic energy and number of head movements during falling from a standing posture on one's back for various variants of falling on the formation of subdural hematomas, subarachnoidal hemorrhages, and brain concussions in the areas of the stroke, contralateral to the stroke, and intermediate. Discloses the correlations between the area and volume of injury and changes in energy parameters of stroke impact. Demonstrates the relationship between the severity of atherosclerotic involvement of the vessels and the volume and type of intracranial injury.

Biomechanical Phenomena↗
PubMed2002

Brain atrophy in mild or moderate traumatic brain injury: a longitudinal quantitative analysis.

BACKGROUND AND PURPOSE: Although mild or moderate traumatic brain injury (TBI) is known to cause persistent neurologic sequelae, the underlying structural changes remain elusive. Our purpose was to assess decreases in the volume of brain parenchyma (VBP) in patients with TBI and to determine if clinical parameters are predictors of the extent of atrophy. METHODS: We retrospectively assessed the total VBP in 14 patients with mild or moderate TBI at more than 3 months after injury and in seven patients at two time points more than 3 months apart. VBP was calculated from whole-brain MR images and then normalized by calculating the percent VBP (%VBP) to correct for intraindividual variations in cranial size. Clinical parameters at the time of trauma were evaluated for potential predictors of atrophy. Findings were compared with those of control subjects of similar ages. RESULTS: In the single time-point analysis, brain volumes, CSF volumes, and %VBP were not significantly different between patients and control subjects. In the longitudinal analysis, the rate of decline in %VBP (0.02 versus 0.0064 U/day, P =.05) and the change in %VBP between the first and second time points (-4.16 +/- 1.68 versus -1.49 +/- 1.7, P =.022 [mean +/-SD]) were significantly greater in patients. Change in %VBP was significantly greater in patients with loss of consciousness (LOC) than in those without LOC (P =.023). CONCLUSION: Whole-brain atrophy occurs after mild or moderate TBI and is evident at an average of 11 months after trauma. Injury that produces LOC leads to more atrophy. These findings may help elucidate an etiology for the persistent or new neurologic deficits that occur months after injury.

Adult↗
PubMedDate not supplied

[Diagnosis and treatment of chronic traumatic subdural hematomas in middle and old age].

The peculiar features of the clinical picture, diagnosis, and surgical treatment of chronic traumatic subdural hematomas were studied in 72 patients of elderly and old age. In 98% of patients they occurred after mild craniocerebral trauma of the type of brain concussion. Local signs prevailed over general cerebral signs in all phases of the disease, productive disorders of consciousness were rare as compared to nonproductive disturbances, marked intellectual-mnemonic disorders were often encountered. Echo-EG, radionuclide scintigraphy, carotid angiography and computed tomography proved to be the most informative paraclinical diagnostic methods. The expediency of performing maximally sparing operative intervention of a short duration in individuals over 60 years of age is pointed out.

Adult↗
PubMed2001

Neurosurgical trauma in People's Republic of China.

An epidemiological investigation for neurological disorders was conducted in the People's Republic of China in 1983 and 1985. The incidence of traumatic neurological injury was 55.4 patients per 100,000 population in the six big cities and 64.1 patients in the 21 rural areas. The mortality rates were 6.3 per 100,000 population (male:female = 1.7:1.0) in the six cities and 9.7 (m:f = 2.5:1) in the rural areas. In the cities, the causes of brain injury were vehicle accidents (31.7%), followed by assaults (23.8%), falls (21.8%), stumbles (15.4%), and others. Brain concussion was 68.4%, contusion was 26.0%, and intracranial hematoma was 5.6%. The incidence of spinal cord injury was 0.67 per 100,000 population in Beijing and 1.37 in Shanghai. Male versus female ratio was 7 to 1 and the peak incidence was found in ages from 20 to 30 years old. In the past decade, vehicle accidents increased along with the increasing number of cars and motor bicycles. As a result of a series of administrative measures, such as improvement of traffic control and safe-driving education, mean mortality decreased from 33.4 per 10,000 motor vehicles in 1990 to 22.0 in 1995. It has been estimated that approximately 50,000 to 60,000 people die from vehicle accidents per year. Among these cases, brain injury accounts for 39% to 57% and spinal cord injury about 10%. Since vehicle accidents are the most common cause for neurotraumatic death, an effort is needed to prevent and to decrease the incidence of these accidental traumatic injuries.

Brain Injuries↗
PubMed2006

Impaired cognitive functions in mild traumatic brain injury patients with normal and pathologic magnetic resonance imaging.

INTRODUCTION: Mild traumatic brain injury (MTBI) is a common neurological (neurotraumatological) diagnosis. As well as different subjective symptoms, many patients develop neuropsychological dysfunction with objective impairment of attention, memory and certain executive functions. Magnetic resonance imaging (MRI) is not routinely used in MTBI patients despite its proven greater sensitivity and specificity in comparison with computed tomography (CT). METHODS: The patient group consisted of 30 persons with MTBI and the control group consisted of 30 sex- and age-matched healthy volunteers. Both groups underwent neurological examination, neuropsychological testing (including the Postconcussion Symptoms Scale questionnaire, PCSS) and brain MRI (the patient group within 96 h after injury). RESULTS: The analyzed groups did not differ significantly in terms of sex, age, or level or duration of education. MRI pathological findings (traumatic and nonspecific) were present in nine patients. Traumatic lesions were found in seven patients. Nonspecific white matter lesions were found in five healthy controls. There were significant differences between MTBI patients and controls in terms of subjective symptoms (PCSS) and selected neuropsychological tests. Statistically significant neuropsychological differences were found between MTBI patients with true traumatic lesions and MTBI patients with nonspecific lesions. CONCLUSION: There is evidence that MTBI patients with true traumatic MRI lesions are neuropsychologically different from MTBI patients with nonspecific MRI lesions or normal brain MRI. These results support the hypothesis that some acute MTBI signs and symptoms have a real organic basis which can be detected by selected new MRI modalities.

Adult↗
PubMed2006

Technetium Tc-99m ethyl cysteinate dimer brain single-photon emission CT in mild traumatic brain injury: a prospective study.

PURPOSE: To explore the role of single-photon emission CT (SPECT) in initial diagnostic evaluation of patients with mild traumatic brain injury (MTBI) and to identify subgroups in which it may serve as a useful diagnostic tool. MATERIALS AND METHODS: Patients with MTBI seen during a 14-month period were prospectively included in this study. All patients had a CT of head within 12 hours of injury and SPECT by using technetium Tc99m ethyl cysteinate dimer (Tc99m-ECD) within 72 hours of injury. Both SPECT and CT findings were compared with clinical features such as posttraumatic amnesia (PTA), postconcussion syndrome (PCS), and loss of consciousness (LOC). RESULTS: Ninety-two patients with MTBI underwent SPECT in the study period. There were 28 children and 64 adults, with male-to-female ratio of 4.5 to 1. CT findings were abnormal in 31 (34%) and SPECT in 58 (63%). The most common abnormality was hypoperfusion in the frontal lobe(s) in adults and the temporal lobe in children. A significantly higher number of perfusion abnormalities were seen in patients with PTA (P = .03), LOC (P = .02), and PCS (P = .01) than in patients without these symptoms. Compared to CT, SPECT had a much higher sensitivity for detecting an organic basis in these subgroup, of patients (P < .05). CONCLUSION: Tc99m-ECD SPECT can be used as a complementary technique to CT in initial evaluation of patients with MTBI. It is particularly useful in patients having PCS, LOC, or PTA with normal CT scan.

Adolescent↗
PubMed2001

Not just malingering: syndrome diagnosis in traumatic brain injury litigation.

When patients present with syndromes we mistrust or misunderstand, clinician are often quick to make a determination of malingering. However, the use of malingering as a default diagnosis neglects a variety of clinical possibilities that may be relevant for treatment and forensic disposition. In neuropsychology, the growing use of a malingering diagnosis has recently been fueled by the increasingly adversarial nature of forensic brain injury litigation in which the goal is often less to provide an objective evaluation of cognition and personality as to brand all personal injury claimants as manipulative frauds. Less maliciously, but still disturbing, neuropsychologists whose knowledge base and clinical experience involves mainly the administration and scoring of psychometric tests may ignorantly, if innocently, overlook alternative diagnoses and syndromes that their education and training have ill-prepared them to recognize. And some patients do indeed malinger, and it is important to identify them, if only to spare legitimately injured claimants from being tarred with the same brush. This paper describes some of the syndromes that may present in clinical and forensic practice with brain-injured patients. It is to be considered a first step toward a practice model of neuropsychology that encourages the role of knowledge and clinical judgement in guiding the meaningful clinical interpretation of tests and measures.

Brain Concussion↗
PubMed1996

[Diffuse ventricular enlargement outlines the late outcome of diffuse axonal brain injury].

Clinical significance of ventriculomegaly after severe head trauma has not been fully explored yet. We analyzed hospital records of 53 cases of diffuse axonal injury and 7 cases of brain concussion together. The follow-up periods ranged from 6 months to 8 years (average 25 months). Four patients underwent CSF shunting without noticeable effect. We classified their outcome according to our modification of the Glasgow outcome scale: vegetated, severe, moderate, mild, fair, and good. We reviewed initial (within 12 hours after injury) CT scans and late (3 to 6 months after injury) CT scans or MRI's. We measured the ratio of the third ventricular width to the inner diameter of the skull on the axial view. We computed the lateral ventricular volume by our newly-devised method which took the partial volume phenomenon into account. Temporary extracerebral fluid accumulation was noted mostly within 3 months after injury in 25 of 39 cases in the mild level or above, and 2 of the 9 fair or good level cases. Ventriculomegaly occurred early and stabilized around the 3 month period. We found the differences between the late and the initial values of the third ventricular width (%) and the lateral ventricular volume (cc) highly correlated with our outcome scale (Spearman's correlation coefficient rs = 0.531, 0.676, respectively with p < 0.001 unanimously). We found the late values themselves of the third ventricular width and the lateral ventricular volume highly correlated with our outcome scale (rs = 0.575, 0.650, respectively with p < 0.001 unanimously). These 4 parameters were also highly correlated with the duration of the initial unconsciousness (LOC). Thus, posttraumatic diffuse ventriculomegaly affecting the third ventricle as well should outline the late outcome of diffuse axonal injury. Both the ventriculomegaly and the late outcome should be roughly predicted by the duration of the initial unconsciousness.

Adolescent↗
PubMedDate not supplied

Mild traumatic brain injury: toward understanding manifestations and treatment.

Mild traumatic brain injury is misleading as a diagnostic term, as it may include a spectrum of manifestations ranging from transient mild symptoms to ongoing disabling problems. It is a source of significant economic burden to society in terms of days lost from work and costs related to medical treatment. Symptomatic individuals will frequently present to primary care general medical practitioners days, weeks, or even months after the trauma. General medical practitioners are thus put in the position of being the "gatekeepers" of medical care for such patients and become responsible for appropriate determination and authorization of medical tests, specialized referrals, and treatment. The purpose of this article, which is based on a review of the literature to 1997, is to provide physicians with an understanding of mild traumatic brain injury, including manifestations and treatment, as it occurs commonly and can significantly impact the quality of life of those affected.

Brain Concussion↗
PubMed1980

Brainstem auditory evoked potentials in postconcussion dizziness.

Twenty-seven patients with postconcussion dizziness following minor injury to the head or neck had brainstem auditory evoked potential studies from one day to eight months (median, 37 days) following injury. All patients were normal on clinical examination at the time of study. Three patients had one or more interpeak latencies prolonged beyond the 99% tolerance limit for normal control subjects. The group mean 1-3, 2-3, and 1-5 interpeak latencies were significantly prolonged. These findings indicate that minor head or neck injury with associated subjective symptomatology may be accompanied by objectively demonstrable brainstem dysfunction.

Adult↗
PubMed1981

Auditory brainstem responses in postconcussion syndrome.

Evidence that head injuries can shear nerve fibers and end bulbs in the tracts between the diencephalon and brainstem led us to hypothesize that auditory brainstem responses might be abnormal in patients with postconcussion syndrome. We recorded brainstem responses in 11 patients and 12 control subjects. Comparing the two populations, our chief finding was that the patients showed significant delays for wave 3. This finding indicates organic changes involving a region at least as central as the superior olivary complex, thus refuting many authors' claims that the syndrome is entirely psychogenic.

Adult↗