Diffuse axonal injury due to lateral head rotation in a rat model

2000 ◽  
Vol 93 (4) ◽  
pp. 626-633 ◽  
Author(s):  
He Xiao-Sheng ◽  
Yi Sheng-Yu ◽  
Zhang Xiang ◽  
Fei Zhou ◽  
Zhang Jian-Ning ◽  
...  

Object. The authors investigated the ramifications of producing diffuse axonal injury (DAI) by lateral head rotation in a rat model.Methods. Using a special injury-producing device, the rat's head was rapidly rotated 90° in the coronal plane at an angular velocity of at least 753.13 rad/second and an angular acceleration of at least 1.806 × 105 rad/second2; the rotation was complete within 2.09 msec. There were no statistically significant changes in PO2, PCO2, pH, or blood pressure values at 5, 15, or 60 minutes after head rotation compared with their respective preinjury baseline values. The rats exhibited posttraumatic behavior suppression for an average of 12.6 minutes. The mortality rate was 17%. The rats that survived had diffuse subarachnoid hemorrhage around the brainstem and upper cervical cord, but no obvious brain contusion. In sections stained with silver or hematoxylin and eosin, axonal swelling and bulblike protrusions at the axonal axis were observed in the medulla oblongata, midbrain, upper cervical cord, and corpus callosum between 6 hours and 144 hours postinjury. The axonal injuries were most severe in the brainstem and were accompanied by parenchymal bleeding. The density of bulblike axonal protrusions peaked 6 hours postinjury in the medulla oblongata and 24 hours postinjury in the midbrain.Conclusions. Rapid lateral head rotation can produce DAI characterized by severe damage to the rat brainstem.

1998 ◽  
Vol 88 (5) ◽  
pp. 795-801 ◽  
Author(s):  
Kim M. Cecil ◽  
Everett C. Hills ◽  
M. Elizabeth Sandel ◽  
Douglas H. Smith ◽  
Tracy K. McIntosh ◽  
...  

Object. This study was conducted to determine whether proton magnetic resonance spectroscopy (MRS) is a sensitive method for detecting diffuse axonal injury, which is a primary sequela of traumatic brain injury (TBI). Diffuse axonal injury is characterized by selective damage to white matter tracts that is caused in part by the severe inertial strain created by rotational acceleration and deceleration, which is often associated with motor vehicle accidents. This axonal injury is typically difficult to detect by using conventional imaging techniques because it is microscopic in nature. The splenium was selected because it is a site vulnerable to shearing forces that produce diffuse axonal injury. Methods. The authors used proton MRS to evaluate the splenium, the posterior commissure of the corpus callosum, in normal control volunteers and in patients with TBI. Proton MRS provided an index of neuronal and axonal viability by measuring levels of N-acetyl aspartate (NAA). Conclusions. A majority of mildly brain injured patients, as well as those more severely injured, showed diminished NAA/creatine (Cr) levels in the splenium compared with normal control volunteers. The patients displaying lowered NAA/Cr in the splenium were also likely to exhibit lowered NAA/Cr in lobar white matter. Also, the levels of NAA/Cr in the splenium of normal volunteers were higher compared with those found in lobar white matter. Decreases in NAA/Cr levels in the splenium may be a marker for diffuse injury. A proton MRS examination may be particularly useful in evaluating mildly injured patients with unexplained neurological and cognitive deficits. It is concluded that MRS is a sensitive tool in detecting axonal injury.


1999 ◽  
Vol 90 (1) ◽  
pp. 206-219 ◽  
Author(s):  
Eduardo Salas ◽  
Laligam N. Sekhar ◽  
Ibrahim M. Ziyal ◽  
Anthony J. Caputy ◽  
Donald C. Wright

Object. The aim of this study was to describe six variations of the extreme-lateral craniocervical approach, their application, and treatment results. Methods. During a 4-year period 69 patients underwent surgery in which six variations of the extreme-lateral craniocervical approach were performed. The variations included: the transfacetal approach (TFA), performed to treat four lesions in the upper cervical spine anterior or anterolateral to the spinal cord; the retrocondylar approach, to treat five intradural lesions located anterolateral to the medulla oblongata and six vascular lesions to expose the extradural segment of the vertebral artery (VA); the partial transcondylar approach (PTCA), to treat 18 intradural lesions located anterior to the medulla oblongata; the complete transcondylar approach (CTCA), to treat 13 extradural lesions that involved the lower clivus and anterior upper cervical spine; the extreme-lateral transjugular approach, to treat 14 jugular foramen tumors; and the transtubercular approach with or without division of the sigmoid sinus, to treat complex VA and vertebrobasilar junction aneurysms. An anatomical prosection was performed to study the surgical exposure of each of the six variations of the extreme-lateral craniocervical approach. Total removal was achieved in 35 (69%) of the patients with tumor; subtotal resection was achieved in 16 (31%) of those patients. In the 12 patients with VA aneurysms, seven underwent clipping, three underwent trapping and a vein graft bypass procedure, and two underwent trapping without the use of a bypass procedure. In five other patients, different cystic, inflammatory, and other vascular lesions were successfully treated. Fifty percent of the patients who underwent surgery via the TFA, 83% via the of the CTCA, and 11% via the PTCA required an occipitocervical fusion procedure. The mean Karnofsky Performance Scale score was 74.7 preoperatively and 76.4 postoperatively. Major complications were hydrocephalus (nine patients), cerebrospinal fluid leakage (seven patients), worsened cranial nerve function (seven patients), vertebrobasilar vasospasm (one patient), and sigmoid sinus thrombosis (one patient). Conclusions. To treat lesions in the region of the foramen magnum and surrounding areas, the approach should be tailored to each specific lesion to provide the needed exposure without unnecessary operative steps.


1998 ◽  
Vol 88 (5) ◽  
pp. 809-816 ◽  
Author(s):  
Andreas Kampfl ◽  
Gerhard Franz ◽  
Franz Aichner ◽  
Bettina Pfausler ◽  
Hans-Peter Haring ◽  
...  

Object. In this retrospective study, the authors analyzed the frequency, anatomical distribution, and appearance of traumatic brain lesions in 42 patients in a posttraumatic persistent vegetative state. Methods. Cerebral magnetic resonance (MR) imaging was used to detect the number of lesions, which ranged from as few as five to as many as 19, with a mean of 11 lesions. In all 42 cases there was evidence on MR imaging of diffuse axonal injury, and injury to the corpus callosum was detected in all patients. The second most common area of diffuse axonal injury involved the dorsolateral aspect of the rostral brainstem (74% of patients). In addition, 65% of these patients exhibited white matter injury in the corona radiata and the frontal and temporal lobes. Lesions to the basal ganglia or thalamus were seen in 52% and 40% of patients, respectively. Magnetic resonance imaging showed some evidence of cortical contusion in 48% of patients in this study; the frontal and temporal lobes were most frequently involved. Injury to the parahippocampal gyrus was detected in 45% of patients; in this subgroup there was an 80% incidence of contralateral peduncular lesions in the midbrain. The most common pattern of injury (74% in this series) was the combination of focal lesions of the corpus callosum and the dorsolateral brainstem. In patients with no evidence of diffuse axonal injury in the upper brainstem (26% in this series), callosal lesions were most often associated with basal ganglia lesions. Lesions of the corona radiata and lobar white matter were equally distributed in patients with or without dorsolateral brainstem injury. Moreover, cortical contusions and thalamic, parahippocampal, and cerebral peduncular lesions were also similarly distributed in both groups. Conclusions. The data indicate that diffuse axonal injury may be the major form of primary brain damage in the posttraumatic persistent vegetative state. In addition, the authors demonstrated in this study that MR imaging, in conjunction with a precise clinical correlation, may provide useful supportive information for the accurate diagnosis of a persistent vegetative state after traumatic brain injury.


2005 ◽  
Vol 103 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Matilde Inglese ◽  
Sachin Makani ◽  
Glyn Johnson ◽  
Benjamin A. Cohen ◽  
Jonathan A. Silver ◽  
...  

Object. Diffuse axonal injury (DAI) is a major complication of traumatic brain injury (TBI) that leads to functional and psychological deficits. Although DAI is frequently underdiagnosed by conventional imaging modalities, it can be demonstrated using diffusion tensor imaging. The aim of this study was to assess the presence and extent of DAI in patients with mild TBI. Methods. Forty-six patients with mild TBI and 29 healthy volunteers underwent a magnetic resonance (MR) imaging protocol including: dual—spin echo, fluid-attenuated inversion recovery, T2-weighted gradient echo, and diffusion tensor imaging sequences. In 20 of the patients, MR imaging was performed at a mean of 4.05 days after injury. In the remaining 26, MR imaging was performed at a mean of 5.7 years after injury. In each case, mean diffusivity and fractional anisotropy were measured using both whole-brain histograms and regions of interest analysis. No differences in any of the histogram-derived measures were found between patients and control volunteers. Compared with controls, a significant reduction of fractional anisotropy was observed in patients' corpus callosum, internal capsule, and centrum semiovale, and there were significant increases of mean diffusivity in the corpus callosum and internal capsule. Neither histogram-derived nor regional diffusion tensor imaging metrics differed between the two groups. Conclusions. Although mean diffusivity and fractional anisotropy abnormalities in these patients with TBI were too subtle to be detected with the whole-brain histogram analysis, they are present in brain areas that are frequent sites of DAI. Because diffusion tensor imaging changes are present at both early and late time points following injury, they may represent an early indicator and a prognostic measure of subsequent brain damage.


2008 ◽  
Vol 48 (8) ◽  
pp. 568-574
Author(s):  
Katsuhisa Masaki ◽  
Masaharu Ohno ◽  
Hironobu Maeda ◽  
Tetsuo Hamada ◽  
Toru Iwaki ◽  
...  

1996 ◽  
Vol 85 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Emile A. M. Beuls ◽  
Marie-Anne M. Vandersteen ◽  
Linda M. Vanormelingen ◽  
Peter J. Adriaensens ◽  
Gerard Freling ◽  
...  

✓ The lower brainstem and cervical spinal cord from an ordinarily treated case of Chiari Type I hindbrain hernia associated with syringomyelia was examined using high-resolution magnetic resonance microscopy and standard neuropathological techniques. Magnetic resonance microscopy allows total screening and visualizes the disturbed internal and external microanatomy in the three orthogonal planes with the resolution of low-power optical microscopy. An additional advantage is the in situ visualization of the shunts. Afterwards the intact specimen is still available for microscopic examination. Part of the deformation of the medulla is caused by chronic tonsillar compression and molding inside the foramen magnum. Other anomalies, such as atrophy caused by demyelination, elongation, and unusual disturbances at the level of the trigeminal and solitary nuclear complexes contribute to the deformation. At the level of the syrinx-free upper part of the cervical cord, anomalies of the dorsal root and the dorsal horn are demonstrated.


2001 ◽  
Vol 94 (4) ◽  
pp. 642-645 ◽  
Author(s):  
Chikanori Inenaga ◽  
Tokutaro Tanaka ◽  
Naoki Sakai ◽  
Shigeru Nishizawa

✓ The authors present the case of a 55-year-old man suffering from intractable spontaneous intracranial hypotension, in whom conservative treatment with 19 weeks of bed rest was not effective. In this period the patient twice underwent surgery for bilateral chronic subdural hematoma, a complication of spontaneous intracranial hypotension. Conventional radionuclide cisternography, magnetic resonance imaging, and computerized tomography myelography did not demonstrate cerebrospinal fluid (CSF) leakage. Repeated radionuclide cisternography with the patient in an upright position revealed leakage of the tracer at upper cervical levels. Computerized tomography myelography with breath holding also showed CSF leakage of the contrast medium bilaterally at upper cervical levels. The patient underwent surgery, and bilateral C-2 and C-3 spinal nerve root pouches were sealed off from the subarachnoid space with oxidized cellulose cotton and fibrin glue. Epiarachnoid spaces around the root sleeves were also sealed to ensure complete resolution of the CSF leakage. After the surgery, the patient was completely free of the disease. In the case of intractable persistent spontaneous intracranial hypotension, surgical treatment is preferable to long-term conservative management. To identify CSF leakage, radionuclide cisternography with the patient in the upright position is useful. When obvious leakage is encountered, surgical sealing of the lesion should be performed via a subarachnoid approach.


1987 ◽  
Vol 66 (3) ◽  
pp. 400-404 ◽  
Author(s):  
Lawrence F. Marshall ◽  
Sharen Knowlton ◽  
Steven R. Garfin ◽  
Melville R. Klauber ◽  
Howard M. Eisenberg ◽  
...  

✓ The results are presented of a prospective study of the course of 283 spinal cord-injured patients who were consecutively admitted to five trauma centers participating in the Comprehensive Central Nervous System Injury Centers' program of the National Institutes of Health. Of the 283 patients, 14 deteriorated neurologically during acute hospital management. In 12 of the 14, the decline in neurological function could be associated with a specific management event, and in nine of these 12 the injury involved the cervical cord. Nine of the 14 patients who deteriorated had cervical injuries, three had thoracic cord injuries, and two had thoracolumbar junction injuries. Management intervention was identified as the cause of deterioration in four of 134 patients undergoing operative intervention, in three of 60 with skeletal traction application, in two of 68 with halo vest application, in two of 56 undergoing Stryker frame rotation, and in one of 57 undergoing rotobed rotation. Early surgery on the cervical spine when cord injury is present appears hazardous, since each of the three patients with a cervical cord injury who deteriorated was operated on within the first 5 days. No such deterioration was observed following surgery performed from the 6th day on. In two other patients, deterioration did not appear to be related to management but was a direct product of the underlying disease or of systemic complications. Deterioration following hospitalization for spinal cord injury is relatively uncommon — 4.9% in this large series. In most instances, decline in function could be attributed to specific management procedures. These changes must not be interpreted as representing failure to provide optimal care but rather should be seen as the inevitable product of an attempt to manage patients with spinal cord and column injuries, many of which are clearly unstable.


2005 ◽  
Vol 2 (3) ◽  
pp. 303-307 ◽  
Author(s):  
Ajay Mantha ◽  
Federico G. Legnani ◽  
Carlos A. Bagley ◽  
Gary L. Gallia ◽  
Ira Garonzik ◽  
...  

Object. Although metastatic spinal disease constitutes a significant percentage of all spinal column tumors, an accessible and reproducible animal model has not been reported. In this study the authors describe the technique for creating an intraosseous spinal tumor model in rats and present a functional and histological analysis. Methods. Eighteen female Fischer 344 rats were randomized into two groups. Group 1 animals underwent a transabdominal exposure and implantation of CRL-1666 breast adenocarcinoma into the L-6 vertebral body (VB). Animals in Group 2 underwent a sham operation. Hindlimb function was tested daily by using the Basso-Beattie-Bresnahan scale. Sixteen days after tumor implantation, animals were killed and their spines were removed for histological assessment. Statistical analysis was performed using the Wilcoxon signed-rank test. By Day 15 functional analysis showed a significant decrease in motor function in Group 1 animals (median functional score 2 of 21) compared with Group 2 rats (median functional score 21 of 21) (p = 0.0217). The onset of paraparesis in Group 1 occurred within 14 to 16 days of surgery. Histopathological analysis showed tumor proliferation through the VB and into the spinal canal, with marked osteolytic activity and spinal cord compression. Conclusions. Analysis of these findings demonstrates the consistency of tumor growth in this model and validates the utility of functional testing for onset of paresis. This new rat model allows for the preclinical evaluation of novel therapeutic treatments for patients harboring metastatic spine disease.


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