Faculty Bibliography

BACKGROUND:Increasing data indicate treatment with beta blockers might improve survival after traumatic brain injury (TBI); the optimal heart rate (HR) range for these patients is unknown. To guide treatment, admission HR in moderate to severe TBI patients was analyzed to determine if a specific range is associated with decreased mortality. METHODS:The Los Angeles County Trauma System Database, consisting of five Level I and 8 Level II trauma centers, was queried for all injured patients admitted between 1998 and 2005 (n = 147,788). Isolated moderate to severe TBI patients (head abbreviated injury score > or = 3) were then identified. Demographics and outcomes were compared at various admission HR subgroups (<50, 50-59, 60-69, 70-79, 80-89, 90-99, 100-109, > or =110). Logistic regression was then performed to determine predictors of mortality. RESULTS:After exclusions, a total of 11,977 isolated moderate to severe isolated TBI patients were analyzed, overall mortality was 11.5% with a trend toward lowest mortality at HR 80 to 89 (7.3%). Each HR subgroup had a significantly increased unadjusted odds ratio for mortality compared with HR 80 to 89, except HR 90 to 99 (OR 1.2, CI 1.0-1.5) and HR 100 to 109 (OR 1.2, CI 1.0-1.5). In multivariable logistic regression analysis, HR <50, 50-59, 60-69, and > or =110 were independent predictors for increased mortality compared with HR 80-89. CONCLUSION/CONCLUSIONS:After isolated moderate to severe TBI, HR <50, 50-59, 60-69, and > or =110 were independent predictors of increased mortality. HR outside the range 70-109 could serve as a marker for aggressive resuscitation. As mortality increased significantly with HR: <50 (AOR 4.70), 50-59 (AOR 2.21), and 60-69 (AOR 1.63), our findings recommend avoiding HR < 70 in patients with moderate to severe TBI.

OBJECTIVE:To identify factors that contribute to intent to donate organs in Hispanic American individuals. DESIGN/METHODS:Cross-sectional telephone surveys. SETTING/METHODS:Four southern California neighborhoods with a high percentage of Hispanic American individuals. PATIENTS/METHODS:Respondents 18 years or older were drawn randomly from lists of Hispanic surnames. MAIN OUTCOME MEASURES/METHODS:Telephone surveys were conducted that measured demographic and socioeconomic factors, cultural factors, awareness and knowledge, and perception and belief regarding organ donation, as well as the intent to become an organ donor. Logistic regression was performed to identify independent contributing factors to intent to register for organ donation. RESULTS:Five hundred twenty-four telephone surveys were conducted over a 3-week period. Seventy-three percent of those surveyed were between the ages of 18 and 44 years and the sample was equally divided between men and women. The following independent risk factors contributed to intent to register: low acculturation (adjusted odds ratio [AOR], 0.39; 95% confidence interval [CI], 0.24-0.62; P < .001), religion (AOR, 0.33; 95% CI, 0.17-0.60; P < .001), perception that the wealthy are more likely to receive organs (AOR, 0.41; 95% CI, 0.25-0.65; P = .001), belief that donation disfigures the body and impacts the funeral (AOR, 0.45; 95% CI, 0.22-0.89; P = .02), and family influence (AOR, 2.02; 95% CI, 1.28-3.22; P = .004). CONCLUSIONS:Among Hispanic American individuals, low acculturation, religion, belief, and family influence affect the intent to register for organ donation. To improve organ donation, these risk factors should be considered using specific, effective educational programs.

BACKGROUND:Male and female nervous systems respond differently to traumatic brain injury (TBI) and in vivo research relates this difference to neuroprotection from female sex hormones. Attempts to replicate female sex hormone-related neuroprotection in clinical studies have been unsuccessful. The objective of this study was to determine whether gender or menopausal status affects mortality in patients with moderate to severe TBI. METHODS:A retrospective review of all patients with isolated moderate to severe TBI was undertaken using data from the National Trauma Database version 6.2 (2000-2005). Isolated TBI was defined as head Abbreviated Injury Score >/=3 in patients without significant extracranial injuries (Abbreviated Injury Score <3 for other anatomic regions). Demographics, Injury Severity Score, and outcomes (mortality, intensive care unit and hospital length of stay, and complications) were compared. The population was stratified into age subgroups: 14 to 45 years (premenopausal), 46 to 55 years (perimenopausal), and older than 55 years (postmenopausal). Logistic regression analysis was used to determine the relationship among female gender, mortality, and development of complications after moderate to severe TBI. RESULTS:A total of 72,294 patients with moderate to severe TBI were evaluated. Females showed a significantly lower risk in both mortality (adjusted odds ratios [AOR], 0.82; 95% confidence intervals [CI], 0.77-0.87; p < 0.0001) and in developing any type of complications (AOR, 0.88; 95% CI, 0.84-0.93; p < 0.0001) than the male population after adjusting for differences in patient characteristics. After age stratification, perimenopausal women (46-55 years) and postmenopausal women (older than 55 years) showed a significantly lower risk in mortality (AOR, 0.76; 95% CI, 0.63-0.92; p < 0.0044 and AOR, 0.79; 95% CI, 0.73-0.86; p < 0.0001, respectively). There was no difference in mortality in premenopausal women compared with their male age-matched counterparts (AOR, 1.09; 95% CI, 0.99-1.21; p = 0.0917). CONCLUSIONS:Female gender is independently associated with reduced mortality and decreased complications after TBI. As peri- and postmenopausal women demonstrated improved survival, and premenopausal women did not, estrogen unlikely confers neuroprotection in women after TBI. Future TBI treatment may benefit with further research focused on why peri- and postmenopausal women show decreased mortality after TBI.

BACKGROUND:Emerging evidence suggests that male and female nervous systems respond differently to traumatic brain injury (TBI). The objective of this study was to examine outcomes between the sexes after TBI. PATIENTS AND METHODS/METHODS:A retrospective review of all severe TBI patients admitted between January and December 2005 was performed. Isolated severe TBI was defined as a head abbreviated injury score greater than 3 with an abbreviated injury score of 3 or less for other anatomic regions. The population was stratified into age subgroups (<14 y, 14-44 y, 45-54 y, and > or =55 y). Logistic regression was used to identify independent predictors of mortality. RESULTS:A total of 1,807 TBI patients were admitted. The mortality was significantly higher for women (43.2% vs 36.2%, P < .01) with an adjusted odds ratio of 1.4 (95% confidence interval, 1.1-1.9, P < .05). After stratification, only women age 55 and older had a significant difference in mortality (odds ratio, 1.71; 95% confidence interval, 1.11-2.62, P = .02). CONCLUSIONS:Female sex (particularly those age > or =55 y) is associated independently with higher mortality in isolated severe TBI. This increased mortality of postmenopausal women after isolated TBI may suggest a hormonal influence and warrants further investigation.

OBJECTIVE:Cranial fixation using pins during neurosurgical procedures is commonplace; however, parameters for the application of these devices in pediatric patients are not well defined. Variability in the thickness of the developing cranium necessitates age-specific considerations to reduce the risk of adverse events. To suggest possible guidelines for the use of cranial fixation pins in children, we surveyed neurosurgeons treating pediatric patients regarding their experience with such devices. METHODS:An Institutional Review Board-approved, 30-item multiple choice survey was provided by electronic mail to 605 neurosurgeons treating pediatric patients. The survey included specific questions regarding their experience with cranial fixation pins with respect to age ranges of patients, selection of pin size, type of pin pressure applied, and complications encountered. RESULTS:One hundred sixty-four (27%) responses were received. One hundred fifty-eight of the 164 (96%) neurosurgeons reported using cranial fixation pins in their pediatric practice. Forty-four of the 164 (27%) apply fixation pins in patients aged 1 to 2 years. Eighty-two (50%) apply pins in patients aged 2 to 3 years, and 89 (54%) apply pins in patients aged 3 to 4 years. For patients aged 2 to 5 years old, the majority of responders use between 10 and 40 pounds of pressure, whereas for those older than 5 years of age, most use between 30 and 40 pounds of pressure. After age 10, patients are treated as adults. Eighty-nine of the 164 (54%) responders reported complications directly related to the use of cranial fixation pins, including cranial fracture, epidural or subdural hematoma, scalp laceration, or cerebrospinal fluid leak. One hundred fifty-four of the 164 (94%) neurosurgeons responded that they are not aware of any standard guidelines for cranial fixation pin use in pediatric patients. Seven (4%) who stated that they were aware of guidelines did not describe where they obtained those guidelines. CONCLUSION/CONCLUSIONS:Cranial fixation pins are widely used among pediatric neurosurgeons in patients younger than 5 years old. Guidelines for their safe use are not well defined despite common use and experience of significant complications associated with such devices.

Giant cell tumors of the bone are rare, locally aggressive lesions that primarily affect the epiphyses of long bones. These tumors can occur in the skull, principally in the sphenoid and temporal bones. Symptoms of these tumors depend on their site of origin but typically include headache, pain, visual field defects, and conductive hearing loss. Histologically, these tumors consist of three cell types: osteoclast-like multinucleated giant cells; round mononuclear cells resembling monocytes; and spindle-shaped, fibroblast-like stromal cells. Radiographically, the tumors appear osteolytic and radiolucent without a sclerotic border. These tumors typically present in the third to fourth decades of life and rarely occur in patients under 20 years of age. The small number of studies of giant cell tumors of the skull has focused on the adolescent and adult populations. The authors report two cases of giant cell tumors of the skull in pediatric patients. In the first case, a 2-year-old girl presented with swelling behind the right ear. In the second case, a 7-week-old girl presented with a mass within the external auditory canal. Both patients underwent metastatic workup and biopsy procedures before resection of the tumor. Both case reports contribute to the literature of giant cell tumors of the skull by describing this condition in pediatric patients. To the authors' knowledge, these cases represent the youngest two patients with giant cell tumors of the skull yet described.

The authors report a case of a 7-month-old infant with a right lateral parietal scalp lesion intermittently leaking fluid similar to cerebrospinal fluid that histologically demonstrated meningothelial and glial cells. At surgical removal, however, no fibrous stalk or bony defect could be identified connecting the lesion with the intracranial compartment. While the embryologic mechanism of this lesion is unclear, the prognosis for normal neurological development appears excellent.

OBJECTIVE:To review the advent and evolution of the football helmet through historical, physiological, and biomechanical analysis. METHODS:We obtained data from a thorough review of the literature. RESULTS:Significant correlation exists between head injuries and the advent of the football helmet in 1896, through its evolution in the early to mid-1900s, and regulatory standards for both helmet use and design and tackling rules and regulations. With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000. Not only is the material used important, but the protective design also proves essential in head injury prevention. Competition among leading helmet manufacturers has benefited the ultimate goal of injury prevention. However, just as significant in decreasing the incidence and severity of head injury is the implementation of newer rules and regulations in teaching, coaching, and governing tackling techniques. CONCLUSION/CONCLUSIONS:Helmet use in conjunction with more stringent head injury guidelines and rules has had a tremendous impact in decreasing head injury severity in football. Modifications of current testing models may further improve helmet design and hence further decrease the incidence and severity of head injury sustained while playing football.

OBJECTIVE:To review head injury in football through historical, anatomic, and physiological analysis. METHODS:We obtained data from a thorough review of the literature. RESULTS:The reported incidence of concussion among high school football players dropped from 19% in 1983 to 4% in 1999. During the 1997 Canadian Football League season, players with a previous loss of consciousness in football were 6.15 times more likely to experience a concussion than players without a previous loss of consciousness (P < 0.05). Players with a previous concussion in football were 5.10 times more likely to experience a concussion than players without a previous concussion (P = 0.0001). With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000. CONCLUSION/CONCLUSIONS:Significant declines in both the incidence and severity of head injury have been observed. The enhanced safety records in football can be attributed to the application of more stringent tackling regulations as well as the evolving football helmet. The role of a neurosurgeon is critical in further head injury prevention and guidelines in sport.