Peter Gruen

Novel diffusion tensor imaging methodology to detect and quantify injured regions and affected brain pathways in traumatic brain injury

PURPOSE To develop and apply diffusion tensor imaging (DTI)-based normalization methodology for the detection and quantification of sites of traumatic brain injury (TBI) and the impact of injury along specific brain pathways in (a) individual TBI subjects and (b) a TBI group. MATERIALS AND METHODS Normalized DTI tractography was conducted in the native space of 12 TBI and 10 age-matched control subjects using the same number of seeds in each subject, distributed at anatomically equivalent locations. Whole-brain tracts from the control group were mapped onto the head of each TBI subject. Differences in the fractional anisotropy (FA) maps between each TBI subject and the control group were computed in a common space using a t test, transformed back to the individual TBI subjects head space, and thresholded to form regions of interest (ROIs) that were used to sort tracts from the control group and the individual TBI subject. Tract counts for a given ROI in each TBI subject were compared to group mean for the same ROI to quantify the impact of injury along affected pathways. The same procedure was used to compare the TBI group to the control group in a common space. RESULTS Sites of injury within individual TBI subjects and affected pathways included hippocampal/fornix, inferior fronto-occipital, inferior longitudinal fasciculus, corpus callosum (genu and splenium), cortico-spinal tracts and the uncinate fasciculus. Most of these regions were also detected in the group study. CONCLUSIONS The DTI normalization methodology presented here enables automatic delineation of ROIs within the heads of individual subjects (or in a group). These ROIs not only localize and quantify the extent of injury, but also quantify the impact of injury on affected pathways in an individual or in a group of TBI subjects.

Surgical management of head trauma

In addition to its inability to predict pressure elevation accurately, head CTs done serially even at 12-hour intervals, cannot adequately portray the dynamic, sometimes rapid evolution (usually growth) of a traumatic hematoma. These limitations aside, CT scanning provides adequate imaging for rational surgical treatment of head injury. Whether for monitoring, diagnostic, or therapeutic purposes, cranial procedures for traumatic pathology are guided by CT.

Three-Layer Reconstruction for Large Defects of the Anterior Skull Base

Objectives To evaluate and discuss a three‐layer rigid reconstruction technique for large anterior skull base defects.

CURRENT TRENDS IN THE MANAGEMENT OF HEAD INJURY

The importance of cerebral perfusion pressure (CPP) optimization has been recognized in the neurosurgical community in the United States as part of the recently published Guidelines for Management of Severe Head Injury. Although further basic and clinical research is needed before a CPP-directed head injury management standard of care is formulated, optimization of CPP is practical with present personnel and equipment resources in many emergency departments. Emergency Department physicians should be familiar with CPP management principles to facilitate interactions with neurosurgical colleagues and improve patient outcomes.

Clinical examination is highly sensitive for detecting clinically significant spinal injuries after gunshot wounds.

BACKGROUND The optimal method for spinal evaluation after penetrating trauma is currently unknown. The goal of this study was to determine the sensitivity and specificity of a standardized clinical examination for the detection of spinal injuries after penetrating trauma. METHODS After Institutional Review Board approval, all evaluable penetrating trauma patients aged 15 years or more admitted to the Los Angeles County + University of Southern California Medical Center were prospectively evaluated for spinal pain, tenderness to palpation, deformity, and neurologic deficit. RESULTS During the 6-month study period, 282 patients were admitted after sustaining a penetrating injury; 143 (50.7%) as a result of gunshot wound (GSW) and 139 (49.3%) as a result of stab wound (SW). None of the patients sustaining a SW had a spinal injury. Of the 112 evaluable GSW patients, 9 sustained an injury: 6 with a true-positive and 3 with a false-negative clinical examination. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 66.7%, 89.6%, 46.2% and 95.2%, respectively. For clinically significant injuries requiring surgical intervention, cervical or thoracolumbar spine orthosis, or cord transections, however, the sensitivity of clinical examination was 100.0%, specificity 87.5%, positive predictive value 30.8%, and negative predictive value 87.5%. CONCLUSION Clinically significant spinal injury, although rare after SWs, is not uncommon after GSWs. A structured clinical examination of the spine in evaluable patients who have sustained a GSW is highly reliable for identifying those with clinically significant injuries.