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[Clinical study of intracranial pressure and auditory brain stem response in the cases of diffuse axonal injury].

The course of intracranial pressure (ICP) and the finding of auditory brain stem response (ABR) was discussed in the cases diagnosed as diffuse axonal injury (DAI) established by Gennarelli. ICP was measured in twenty-six cases which were divided into three groups according to the course of ICP: Group (1), in which ICP remained below 20 mmHg (group I, 9 cases). Group (2), in which ICP rose above 20 mmHg but was controlled by therapy (group II, 8 cases). Group (3), in which ICP rose above 20 mmHg and could not be controlled by any therapies (group III, 9 cases). Glasgow outcome scale 3 months after the injury in the cases of group I and II was severe disability (SD) and/or persistent vegetative state (PVS), but all of the cases in group III died. The findings of serial ABR were divided into 3 groups. These were group A (2 cases) which showed normal record, group B (5 cases) which showed elongation of latencies between the first and fifth waves, and group C (5 cases) in which there was no response in ABR. GOS in group A or B was SD and/or PVS, but all of the cases in group C were shown to be dead in GOS. Our studies suggest that the level of ICP in DAI is rather higher than that published in previous reports, and the continuous measurements of ICP and serial records of ABR are useful for evaluating the outcome of DAI.

Adolescent↗

Cleft cavum of the septum pellucidum in victims of fatal road traffic accidents: a distinct type of cavum associated with severe diffuse axonal injury.

BACKGROUND: The cavum of the septum pellucidum (CSP) is a small cavity constantly present in fetuses and newborns, of variable frequency among necropsied adults and with a high frequency in professional boxers. METHOD: A pathologic study was conducted on brains of 626 patients without a history of head trauma (group 1) autopsied consecutively from a general hospital and of 120 random victims of fatal road traffic accidents (group 2). RESULTS: In group 1, 237 (37.9%) cases of CSP were observed, virtually all in a triangular or trapezoidal shape. In group 2, 65 (54.2%) cases of CSP were observed, 50 (76.9%) in triangular or trapezoidal shape and 15 (23.1%) in cleft shape. Cleft CSP was always associated with severe diffuse axonal injury (grades 2 and 3). CONCLUSION: Although described in boxers, the CSP has not been reported in other types of head injury. The largest frequency of CSP found in fatal victims of head trauma, particularly in patients with severe diffuse axonal lesion (grades 2 and 3), when compared with the individuals without a history of head trauma, suggests that the high-intensity angular acceleration of the head causes complementary and independent displacement of the 2 cerebral hemispheres and dislocation of one of the leaves of the septum pellucidum on the other. This could result in separation of the 2 leaves and formation of CSP, usually in cleft shape.

Acceleration↗

Freeze-fracture studies of reactive myelinated nerve fibres after diffuse axonal injury.

We have studied the axonal and myelin sheath response in diffuse axonal injury after angular acceleration using the freeze-fracture and thin section techniques. It was found that the glial-axonal junction was intact until 1 h after injury. But upon loss of the nodal axolemma specialisations, after 3 to 4 h, the dimeric particles of the glial-axonal junction (GAJ) were lost and, by 6 h, the myelin lamellae became separated from the axonal remnant. There was a correlated loss of glial membrane specialisations of the GAJ during this separation. In the internodal region a suggestion of membrane damage occurred after 20 min but discrete myelin dislocations (particle-free areas) were not found until 1-h survival and were extensive by 6 h. Areas of loosely organised myelin occurred between intact axons at 7-28 days after injury. No evidence for growth cone formation was obtained.

Animals↗

Hemorrhagic shearing lesions in children and adolescents with posttraumatic diffuse axonal injury: improved detection and initial results.

PURPOSE: To compare the effectiveness of a high-spatial-resolution susceptibility-weighted (SW) magnetic resonance (MR) imaging technique with that of a conventional gradient-recalled-echo (GRE) MR imaging technique for detection of hemorrhage in children and adolescents with diffuse axonal injury (DAI). MATERIALS AND METHODS: Seven young patients with a mean Glasgow Coma Scale score of 7 +/- 4 (SD) at admission were imaged a mean of 5 days +/- 3 after injury. High-spatial-resolution three-dimensional GRE imaging performed with postprocessing by using a normalized phase mask was compared with conventional GRE MR imaging. The total and mean values of lesion number and apparent hemorrhage volume load determined with both examinations were compared. Mean values were compared by using paired t test analysis. Differences were considered to be significant at P < or =.05. RESULTS: Hemorrhagic lesions were much more visible on SW MR images than on conventional GRE MR images. SW MR imaging depicted 1,038 hemorrhagic DAI lesions with an apparent total hemorrhage volume of 57,946 mm3. GRE MR imaging depicted 162 lesions with an apparent total hemorrhage volume of 28,893 mm3. SW MR imaging depicted a significantly higher mean number of lesions in all patients than did GRE MR imaging, according to results of visual (P =.004) and computer (P =.004) counting analyses. The mean hemorrhage volume load for all patients also was significantly greater (P =.014) by using SW MR imaging according to computer analysis. SW MR imaging appeared to depict much smaller hemorrhagic lesions than GRE MR imaging. The majority (59%) of individual hemorrhagic DAI lesions seen on SW MR images were small in area (<10 mm(2)), whereas the majority (43%) of lesions seen on GRE images were larger in area (10-20 mm(2)). CONCLUSION: SW MR imaging depicts significantly more small hemorrhagic lesions than does conventional GRE MR imaging and therefore has the potential to improve diagnosis of DAI.

Adolescent↗

Hypoflow and hyperflow in diffuse axonal injury. Prognostic and therapeutic implications of transcranial Doppler sonography evaluation.

BACKGROUND: In the present report we describe the results of a study aimed at evaluating the cerebral haemodynamics and the neuroradiological findings observ-ed in 7 consecutive patients, 4 adults and 3 children (6, 8 and 10 years old), affected by diffuse axonal injury (DAI). METHODS: All the patients were admitted to the Paediatric or Adult Intensive Care Unit with GCS scores less than 8 after a severe brain injury. Serial head CT scan and trans-cranial Doppler sonography (TCD) examinations were carried out in all patients; MRI was carried out in the paediatric patients only. TCD of the middle cerebral arteries was performed through the temporal bone window. In 6 cases (2 paediatric) diuretic osmotic therapy was immediately administered and in 6 cases (3 paediatric) barbiturates and hyperventilation were also used. RESULTS: Hyperflow, variably responsive to barbiturate therapy of vasoparalysis, was observed in all paediatric patients and in 3 adult subjects (85.7%: 6 out of 7 pa-tients) by means of TCD. CONCLUSIONS: Observation of these phenomena allowed us to modify the pharmacological treatment and/or perform external cerebrospinal fluid (CSF) drainage (4 cases). Compartimental hyperflow TCD pattern was evident in 1 patient. Although the limited number of patients in our series does not allow definitive conclusions, we strongly believe that TCD monitoring is an useful tool in planning surgical strategy in patients with DAI.

Accidents, Traffic↗

The expression and changes of heat shock protein 70, MDA and haemorheology in rat cortex after diffuse axonal injury with secondary insults.

In the present study the role of heat shock protein 70 (HSP70) expression, changes of malonyldialdehyde (MDA) in rat cortex and haemorheology with time after diffuse axonal injury (DAI) only and DAI with secondary insults (SI) were studied. The rat DAI and DAI with SI model were made according to our previous work and animals were divided into a control and another five injury groups with time after injury. Immunohistochemical assay was used to detect the neuronal expression of HSP70 at 0.5h, 3h, 12h, 24h, 72h after DAI or DAI with SI. In the meantime, the high (etah ) and low whole blood viscosity (etaL ), haematocrit (HCT) and RBC aggregation index (AI = etaL/etah ) were also detected and calculated. MDA in the homogenised brain tissue was assayed by thiobarbituric acid (TBA) reaction. The results showed that HSP70 positive neurons were not detected at 30 minutes, but the number of HSP70 positive neurons begin to increase obviously at 3 hours, reach a peak at 24 hours (P< 0.01), and decrease at 72 hours (P= 0.05) after brain injury. The trend of expression of HSP70 was alike for both DAI only or DAI with SI. Meanwhile, MDA, etah, etaL, HCT and AI changes showed the same tendency. Compared with DAI only group, MDA and blood viscosity indexes in DAI with SI were significantly higher at respective time points (P< 0.01). It is concluded that HSP70 expression, MDA and haemorheology indices increased after brain injury and brain injury with SI. Free radicals and haemorheological changes play an important role in the aggravation of brain damage and HSP70 expression upregulation.

Animals↗

Outcome of patients with diffuse axonal injury: the significance and prognostic value of MRI in the acute phase.

BACKGROUND: To compare the magnetic resonance imaging (MRI) findings in the acute phase with outcome in patients with diffuse axonal injury (DAI). METHODS: A group of 33 patients with closed head injury and discrepancy between the apparently normal computed tomographic scan findings and their neurologic statuses were studied with MRI during the first 48 hours. Among them, 24 were found to suffer from DAI-type lesions. According to the Glasgow Coma Scale (GCS), 19 patients suffered from severe head injury (GCS score <8) and 5 patients had moderate head injury (GCS score of 9-12). Four MRI sequences in various planes were applied. Patients were divided into three groups, according to staging described in the literature. RESULTS: In five patients, MRI demonstrated nonhemorrhagic DAI lesions stage 1. In 11 patients, findings were consistent with DAI lesions stage 2, eight nonhemorrhagic and three hemorrhagic. Eight patients showed DAI lesions stage 3, six of which were nonhemorrhagic. CONCLUSIONS: MRI is more sensitive compared with computed tomography in the detection of traumatic brain lesions, especially the nonhemorrhagic DAI. The presence of hemorrhage in DAI-type lesions and the association with traumatic space-occupying lesions is a poor prognostic sign. Isolated nonhemorrhagic DAI-type lesions are not associated with poor clinical outcome.

Adolescent↗

Magnetization transfer imaging of diffuse axonal injury following experimental brain injury in the pig: characterization by magnetization transfer ratio with histopathologic correlation.

PURPOSE: Our goal was to evaluate the use of the magnetization transfer ratio (MTR) in the detection of diffuse axonal injury (DAI) resulting from traumatic brain injury in a swine model. METHOD: DAI was created by applying a nonimpact, coronal plane, rotational acceleration to the heads of miniature swine (n = 4). GE imaging was performed with and without off-resonance MT saturation. Histologic correlation of axonal injury with MRI was performed 7 days postinjury. Thirty-one subcortical white matter regions and 10 deep white matter regions were selected for the direct comparison of histologic data and MTR measurements. RESULTS: Nineteen of 41 examined locations exhibited histologic evidence of axonal injury. The mean MTR in regions with axonal damage was significantly less than in regions without axonal damage. These changes were observed both in regions demonstrating high signal intensity on T2-weighted images (T2WI) (p <0.0001, n = 6) and in regions with no signal intensity change on T2WI (p < 0.05, n = 13). CONCLUSION: These results suggest that the measurement of MTR may have the potential for evaluation axonal damage in DAI following traumatic brain injury even when conventional T2WI does not demonstrate the lesion.

Animals↗

Diffuse axonal injury associated with multiple traumatic aneurysms of the distal anterior cerebral artery--case report.

A rare case of multiple traumatic aneurysms, arising from the distal anterior cerebral artery (ACA), associated with a diffuse axonal injury is presented. An 18-year-old male sustained a frontal impact injury in a traffic accident on February 19, 1988. He immediately lost consciousness and was transported to a local hospital where his Glasgow Coma Scale score was 6. A computed tomographic scan showed a traumatic subarachnoid hemorrhage extending from the corpus callosum to the left parietal lobe. With conservative treatment, he gradually regained consciousness and was referred to our hospital 12 days later. Skull x-rays revealed no fracture. A right common carotid angiogram revealed multiple aneurysmal dilatations on the right distal ACA. A left frontoparietal craniotomy was then performed to determine the nature of the aneurysmal dilatation, and to evacuate the intracerebral hematoma because his right hemiparesis persisted. Two aneurysmal dilatations on the distal ACA were tightly surrounded by clots and a hematoma extended from the corpus callosum to the parietal lobe. The ACA was trapped proximal and distal to the aneurysmal dilatations. The postoperative course was uneventful.

Adolescent↗

Apoptotic change in response to magnesium therapy after moderate diffuse axonal injury in rats.

The biochemical factors related to moderation of secondary or delayed damage to the central nervous system (CNS) remain undefined. We have recently demonstrated that the weight- drop induced moderate diffuse axonal injury (mDAI) in rats causes a rapid decline in serum ionized magnesium (Mg(2+)) and a significant increase in the amount of serum ionized calcium (Ca(2+)) relative to Mg(2+) (Ca(2+)/ Mg(2+)). For three hours, serum Mg(2+) levels remained significantly depressed at 76% of preinjury values (p < 0.05), but total serum magnesium remained unchanged (tMg, p > 0.05). Head trauma resulted in a small decrease of Ca(2+) (about 10%), but a significant increase in the amount of Ca(2+)/Mg(2+) (mean value in control group: in injured group for 3 hours after trauma =4.65 +/- 0.012 : 5.69 +/- 0.015, p < 0.05) was observed. In order to further investigate the relationship between Mg(2+) and brain injury, the effect of Mg(2+) treatment on posttraumatic histological changes (apoptotic changes) was examined following the weight-drop induced brain injury. At 30 min postinjury, animals treated with MgSO(4) (750 micromol/kg) showed significant improvements of apoptotic changes when compared to the control group (54.8 +/- 1.7, 51.5 +/- 3.2 at 12, 24 h in control group, 24.8 +/- 2.6, 20.5 +/- 1.4 at 12, 24 h in treated group, p < 0.05). The early decline in serum Mg(2+) and the increase in the amount of Ca(2+)/Mg(2+) immediately following brain trauma uncovered by these findings suggest that they may be a critical factor in the development of irreversible tissue injury. If this proves to be the case, treatment with MgSO(4) may be effective in improving histological findings following experimental traumatic brain injury in rats.

Animals↗

Diffuse axonal injury and traumatic coma in the primate.

Traumatic coma was produced in 45 monkeys by accelerating the head without impact in one of three directions. The duration of coma, degree of neurological impairment, and amount of diffuse axonal injury (DAI) in the brain were directly related to the amount of coronal head motion used. Coma of less than 15 minutes (concussion) occurred in 11 of 13 animals subjected to sagittal head motion, in 2 of 6 animals with oblique head motion, and in 2 of 26 animals with full lateral head motion. All 15 concussioned animals had good recovery, and none had DAI. Conversely, coma lasting more than 6 hours occurred in one of the sagittal or oblique injury groups but was present in 20 of the laterally injured animals, all of which were severely disabled afterward. All laterally injured animals had a degree of DAI similar to that found in severe human head injury. Coma lasting 16 minutes to 6 hours occurred in 2 of 13 of the sagittal group, 4 of 6 in the oblique group, and 4 of 26 in the lateral group, these animals had less neurological disability and less DAI than when coma lasted longer than 6 hours. These experimental findings duplicate the spectrum of traumatic coma seen in human beings and include axonal damage identical to that seen in sever head injury in humans. Since the amount of DAI was directly proportional to the severity of injury (duration of coma and quality of outcome), we conclude that axonal damage produced by coronal head acceleration is a major cause of prolonged traumatic coma and its sequelae.

Acceleration↗

[Clinicopathological studies of diffuse axonal injury--five autopsy cases].

In severe head injuries, delayed intracerebral hematoma appearing lately is noted due to the spread use of serial CT scan. The authors experienced the autopsy of 5 cases who presented diffuse axonal injury (DAI) among these new lesions in repeated CT scan findings and report the pathohistological findings. Subjects were as follows: The age range of the patients was 15 to 25 years. The consciousness levels of the 5 cases on admission were 6 or less by the Glasgow coma scale. CT findings of DAI were revealed hemorrhage of the corpus callosum, basal ganglia, tegmentum of pons, intraventricular, and acute brain swelling. Total clinical courses were 2 to 29 days, but most of them were 9 or less days. In the macroscopic findings, marked congestion and edema revealed mainly in deep part of the white matter of the frontal lobe in all 5 cases. Callosal disruption and hematoma adjacent the corpus callosum revealed in 4 out of 5 cases. Cerebral contusion with hemorrhage revealed in 3 out of 5 cases. Intraventricular hemorrhage and traumatic subarachnoid hemorrhage revealed in 2 out of 5 cases. Hemorrhage of basal ganglia and base of pons revealed in 2 cases. Microscopic examination of all 5 cases revealed pallor of myelin in the corpus callosum and white matter surrounding hemorrhagic lesion, and abnormal tortuous, swelling and fragmentation of axons in stained preparation. Axonal retraction ball was recognized in 3 out of 5 cases. In conclusion, five autopsied cases who presented acute brain swelling and hemorrhage of corpus callosum and tegmentum of pons in serial CT scan were examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The diagnosis of diffuse axonal injury in routine autopsy practice.

A 40-year-old pedestrian was involved in a road traffic accident. He lost consciousness immediately and remained comatose for 6 months until he died of a bronchopneumonia. Examination of the fixed brain revealed the late results of diffuse axonal injury. Not all the features were readily visible macroscopically, but required a limited number of histological sections from readily predictable sites for demonstration. Special stains played only a confirmatory role. This case illustrates some of the problems in diagnosing one of the commoner patterns of brain damage in head injury, and shows how the problem may best be approached in practice.

Accidents, Traffic↗

Cognitive dysfunction and histological findings in rats with chronic-stage contusion and diffuse axonal injury.

The Morris water maze (MWM) technique is well known as a prominent method of evaluating learning acquisition and memory retention impairments in rats. We previously reported on a modified fluid percussion device that is able to consistently produce experimental cortical contusion (CC) and diffuse axonal injury (DAI) in separate groups of rats. The purpose of the present protocol is to evaluate the differences in learning acquisition and memory retention impairments between these two types of injured rats in the chronic stage using the MWM technique. CC and DAI rats are respectively induced by lateral and midline fluid percussion. We also compare the histological differences between these two different types of traumatic brain injury. The results show statistically significant differences in learning acquisition impairment between the sham and CC rats and between the sham and DAI rats. However, a difference in memory retention impairment was expected to be seen only between the sham and DAI rats. Histologically, the loss of CA3 pyramidal cells in the hippocampus was observed ipsilaterally in the CC and bilaterally in DAI. Neuronal cell loss was observed in bilaterally in layer II of the entorhinal cortex in DAI, but not in CC.

Animals↗

Intra-axonal overloading of calcium ion in rat diffuse axonal injury and therapeutic effect of calcium antagonist.

OBJECTIVE: Exploring the intra-axonal overloading of calcium ion (Ca(2+)) in brain diffuse axonal injury (DAI) and the therapeutic effect of calcium antagonist(Nimotop) on DAI. METHODS: Fourteen SD rats were divided into injury group, treatment group and control group. The DAI model of rats was produced by using a head-instant-axial-rotation device. Tissues from the medulla oblongata of rats were taken 2-24 h post-injury and processed for electron microscopic observation by a cytochemical technique for calcium ion. RESULTS: In the injured rats there was evidence of local disruption of myelin sheath,lucent spaces between myelin sheath lamellae, separation of axolemma from the inner layer of myelin sheath, peripheral accumulation of organellae, intra-axonal formation of vacuoles and reduction of mitochondria. A large number of fine calcium deposits were seen on the affected myelin sheath. The severity of the myelin sheath lesion was related positively to the number of calcium deposits on it. In the later post-injury period the coarse calcium particles appeared within the damaged axon. Neuronal somas and microvascular endotheliums showed a lot of vacuoles and some fine calcium deposits. Many microvilli formed on the luminal aspect of endothelium. In the treatment group myelin sheath tended to be injured locally, and axoplasmic mitochondria were nearly normal in number, structure, and distribution. Few calcium deposits were found in axons. Vacuolization was obviously reduced in neuronal soma and endothelium. CONCLUSIONS: In DAI there exists an intra-axonal overloading of calcium ion, which is a key factor to the occurrence and development of DAI. Early use of Nimotop can alleviate DAI.

Journal Article↗

Diffuse axonal injury with brainstem localisation: report of a case in a mild head injured patient.

The authors present the case of a 26-yrs-old woman admitted into our hospital after a severe polytrauma with a mild head injury. CT scanning disclosed two small hemorrhages located in her brainstem and mesial temporal lobe. After splenectomy the patient made a full recovery without neurological sequelae. Radiological signs of diffuse axonal injury even in the brainstem may be present in a clinically mild head injury.

Accidents, Traffic↗