Incidence of surgically treated chronic subdural hematoma after head injury with normal initial computed tomography.

PURPOSE: The objective was to determine the incidence of surgically treated chronic subdural hematoma (cSDH) within six months after head trauma in a consecutive series of head injury patients with a normal initial computed tomography (CT). METHODS: A total of 1941 adult patients with head injuries who underwent head CT within 48 h after injury and were treated at the Tampere University Hospital's emergency department were retrospectively evaluated from medical records (median age = 59 years, IQR = 39-79 years, males = 58%, patients using antithrombotic medication = 26%). Patients with no signs of acute traumatic intracranial pathology or any type of subdural collection on initial head CT were regarded as CT negative (n = 1573, 81%). RESULTS: Two (n = 2) of the 1573 CT negative patients received surgical treatment for cSDH. Consequently, the incidence of surgically treated cSDH after a normal initial head CT during a six-month follow-up was 0.13%. Both patients sustained mild traumatic brain injuries initially. One of the two patients was on antithrombotic medication (warfarin) at the time of trauma, hence incidence of surgically treated cSDH among patients with antithrombotic medication in CT negative patients (n = 376, 23.9%) was 0.27%. Additionally, within CT negative patients, one subdural hygroma was operated shortly after trauma. CONCLUSION: The extremely low incidence of surgically treated cSDH after a normal initial head CT, even in patients on antithrombotic medication, supports the notion that routine follow-up imaging after an initial normal head CT is not indicated to exclude the development of cSDH. Additionally, our findings support the concept of cSDH not being a purely head trauma-related disease.

Incidence of surgically treated post-traumatic hydrocephalus 6 months following head injury in patients undergoing acute head computed tomography.

BACKGROUND: Post-traumatic hydrocephalus (PTH) is a well-known complication of head injury. The percentage of patients experiencing PTH in trauma cohorts (0.7-51.4%) varies greatly in the prior literature depending on the study population and applied diagnostic criteria. The objective was to determine the incidence of surgically treated PTH in a consecutive series of patients undergoing acute head computed tomography (CT) following injury. METHODS: All patients (N = 2908) with head injuries who underwent head CT and were treated at the Tampere University Hospital's Emergency Department (August 2010-July 2012) were retrospectively evaluated from patient medical records. This study focused on adults (18 years or older) who were residents of the Pirkanmaa region at the time of injury and were clinically evaluated and scanned with head CT at the Tampere University Hospital's emergency department within 48 h after injury (n = 1941). A thorough review of records for neurological signs and symptoms of hydrocephalus was conducted for all patients having a radiological suspicion of hydrocephalus. The diagnosis of PTH was based on clinical and radiological signs of the condition within 6 months following injury. The main outcome was surgical treatment for PTH. Clinical evidence of shunt responsiveness was required to confirm the diagnosis of PTH. RESULTS: The incidence of surgically treated PTH was 0.15% (n = 3). Incidence was 0.08% among patients with mild traumatic brain injury (TBI) and 1.1% among those with moderate to severe TBI. All the patients who developed PTH underwent neurosurgery during the initial hospitalization due to the head injury. The incidence of PTH among patients who underwent neurosurgery for acute traumatic intracranial lesions was 2.7%. CONCLUSION: The overall incidence of surgically treated PTH was extremely low (0.15%) in our cohort. Analyses of risk factors and the evaluation of temporal profiles could not be undertaken due to the extremely small number of cases.

Incidence and Associated Factors of Anemia in Patients with Acute Moderate and Severe Traumatic Brain Injury.

BACKGROUND: Anemia might contribute to the development of secondary injury in patients with acute traumatic brain injury (TBI). Potential determinants of anemia are still poorly acknowledged, and reported incidence of declined hemoglobin concentration varies widely between different studies. The aim of this study was to investigate the incidence of severe anemia among patients with moderate to severe TBI and to evaluate patient- and trauma-related factors that might be associated with the development of anemia. METHODS: This retrospective cohort study involved all adult patients admitted to Tampere University Hospital's emergency department for moderate to severe TBI (August 2010 to July 2012). Detailed information on patient demographics and trauma characteristics were obtained, including data on posttraumatic care, data on neurosurgical procedures, and all measured in-hospital hemoglobin values. Severe anemia was defined as a hemoglobin level less than 100 g/L. Both univariate and multivariable analyses were performed, and hemoglobin trajectories were created. RESULTS: The study included 145 patients with moderate to severe TBI (male 83.4%, mean age 55.0 years). Severe anemia, with a hemoglobin level less than 100 g/L, was detected in 66 patients (45.5%) and developed during the first 48 h after the trauma. In the univariate analysis, anemia was more common among women (odds ratio [OR] 2.84; 95% confidence interval [CI] 1.13-7.15), patients with antithrombotic medication prior to trauma (OR 3.33; 95% CI 1.34-8.27), patients with cardiovascular comorbidities (OR 3.12; 95% CI 1.56-6.25), patients with diabetes (OR 4.56; 95% CI 1.69-12.32), patients with extracranial injuries (OR 3.14; 95% CI 1.69-12.32), and patients with midline shift on primary head computed tomography (OR 2.03; 95% CI 1.03-4.01). In the multivariable analysis, midline shift and extracranial traumas were associated with the development of severe anemia (OR 2.26 [95% CI 1.05-4.48] and OR 4.71 [95% CI 1.74-12.73], respectively). CONCLUSIONS: Severe anemia is common after acute moderate to severe TBI, developing during the first 48 h after the trauma. Possible anemia-associated factors include extracranial traumas and midline shift on initial head computed tomography.

Preexisting conditions in older adults with mild traumatic brain injuries.

OBJECTIVE: This study examined the prevalence of preexisting conditions that could affect premorbid brain health, cognition, and functional independence among older adults with mild traumatic brain injury (MTBI), and the relationship between preexisting conditions, injury characteristics, and emergency department (ED) discharge location (home versus continued care). METHODS: Older adults (N = 1,427; 55-104 years-old; 47.4% men) who underwent head computed tomography (CT) after acute head trauma were recruited from the ED. Researchers documented preexisting medical conditions retrospectively from hospital records. RESULTS: Multiple preexisting conditions increased in frequency with greater age, including circulatory and nervous system diseases and preexisting abnormalities on head CT. Psychiatric and substance use disorders (SUDs) decreased in frequency with greater age. Among participants with uncomplicated MTBI and GCS = 15, preexisting nervous system diseases and preexisting CT abnormalities were associated with higher odds of continued care for all participants, whereas psychiatric disorders and SUDs were only associated with higher odds of continued care among participants <70 years-old. Preexisting circulatory diseases, loss of consciousness, and amnesia were unassociated with discharge location. CONCLUSIONS: Preexisting medical conditions that could affect brain and cognitive health occur commonly among older adults who sustain MTBIs. These conditions can confound research examining post-injury outcomes within this age group.

Violence-related traumatic brain injury.

Objectives: The purpose of this study was to determine the unique characteristics of violence-related traumatic brain injuries (TBI). Methods: All consecutive patients who underwent head CT due to an acute head injury (n = 3023) at the Emergency Department of Tampere University Hospital (Aug 2010-Jul 2012) were included. A detailed retrospective data collection was conducted in relation to demographics, injury-related data, premorbid health, clinical characteristics, and neuroimaging findings. Results: Patients with violence-related TBIs (n = 222) were compared to patients who sustained a TBI by other mechanisms (n = 2801). Statistically significant differences were found on age, gender, prior circulatory system disease, prior mental or behavioral disorders, chronic alcohol abuse, regular substance abuse, regular medication, alcohol intoxication at the time of injury, narcotics intoxication at the time of injury, and acute traumatic lesion on head CT. The groups did not differ on clinical signs of TBI severity. Conclusions: Young adult males with premorbid mental health history and chronic alcohol abuse are most prone to sustain a TBI due to a violence-related incident. Incidents are often related to alcohol intoxication. However, violence was not consistently associated with more severe TBIs than other mechanisms of injury.

Head injuries and the risk of concurrent cervical spine fractures.

BACKGROUND: Cervical spine injuries of variable severity are common among patients with an acute traumatic brain injury (TBI). We hypothesised that TBI patients with positive head computed tomography (CT) scans would have a significantly higher risk of having an associated cervical spine fracture compared to patients with negative head CT scans. METHOD: This widely generalisable retrospective sample was derived from 3,023 consecutive patients, who, due to an acute head injury (HI), underwent head CT at the Emergency Department of Tampere University Hospital (August 2010-July 2012). Medical records were reviewed to identify the individuals whose cervical spine was CT-imaged within 1 week after primary head CT due to a clinical suspicion of a cervical spine injury (CSI) (n = 1,091). RESULTS: Of the whole cranio-cervically CT-imaged sample (n = 1,091), 24.7% (n = 269) had an acute CT-positive TBI. Car accidents 22.4% (n = 244) and falls 47.8% (n = 521) were the most frequent injury mechanisms. On cervical CT, any type of fracture was found in 6.6% (n = 72) and dislocation and/or subluxation in 2.8% (n = 31) of the patients. The patients with acute traumatic intracranial lesions had significantly (p = 0.04; OR = 1.689) more cervical spine fractures (9.3%, n = 25) compared to head CT-negative patients (5.7%, n = 47). On an individual cervical column level, head CT positivity was especially related to C6 fractures (p = 0.031, OR = 2.769). Patients with cervical spine fractures (n = 72) had altogether 101 fractured vertebrae, which were most often C2 (22.8, n = 23), C7 (19.8%, n = 20) and C6 (16.8%, n = 17). CONCLUSIONS: Head trauma patients with acute intracranial lesions on CT have a higher risk for cervical spine fractures in comparison to patients with a CT-negative head injury. Although statistically significant, the difference in fracture rate was small. However, based on these results, we suggest that cervical spine fractures should be acknowledged when treating CT-positive TBIs.

Clinical correlates of retrograde amnesia in mild traumatic brain injury.

PRIMARY OBJECTIVE: The purpose of this study was to examine the clinical significance of retrograde amnesia (RA) in patients with acute mild traumatic brain injuries (MTBI). METHODS AND PROCEDURES: An emergency department sample of patients (n = 75), aged 18-60 years, with no pre-morbid medical or psychiatric conditions, who met the WHO criteria for MTBI were enrolled in this prospective, descriptive, follow-up study. This study examined the presence and duration of RA in relation to socio-demographics, MTBI severity markers including neuroimaging (CT, MRI) and clinical outcomes (Rivermead post-concussion symptoms questionnaire, post-concussion syndrome (PCS) diagnosis and return to work (RTW) status) at 2 weeks, 1 month and 6 months post-injury. MAIN OUTCOMES AND RESULTS: GCS scores and duration of post-traumatic amnesia (PTA) were related to RA. Those with GCS scores of 14 vs. 15 were more likely to have RA (χ(2)(1) = 13.70, p < 0.0001) and a longer duration (Mann-Whitney U = 56.0, p < 0.0001, d = 1.15) of RA. The duration of RA and PTA correlated positively (Spearman ρ(75) = 0.42, p < 0.0001) and those with RA had longer durations of PTA (Mann-Whitney U = 228.5, p = 0.001, d = 1.21). During the follow-up, the presence and duration of RA were not significantly associated with PCS diagnosis or time to RTW. CONCLUSIONS: In this study, the presence and duration of RA was not associated with outcome.

Acute assessment of brain injuries in ground-level falls.

OBJECTIVE: The purpose of this study was to characterize traumatic brain injuries (TBI) sustained in ground-level falls (GLFs). The focus was on factors associated with acute computed tomographic (CT) findings. METHODS: The sample included 575 subjects examined and treated at the Tampere University Hospital emergency department (ED). Retrospective data collection consisted of subject- and injury-related data and clinical information from the emergency department. All CT scans were analyzed and systematically coded. RESULTS: Ground-level falls were the mechanism of injury in 48.3% (n = 278) of the subjects. In the GLF group, independent risk factors for acute traumatic CT findings were long-term alcohol abuse, older age, being found on the ground, and left temporoparietal and occipital location of direct head impact. There were no significant differences in the incidence of any intracranial traumatic lesion type between those with GLFs and other causes of TBI. None of the classic clinical TBI severity markers studied were associated with acute traumatic CT findings in patients with GLFs. CONCLUSIONS: Older age and long-term alcohol abuse increase the likelihood of acute intracranial CT abnormalities. The pattern of intracranial traumatic CT findings does not differ from other causes of TBI. Clinical signs and indices of TBI severity did not predict traumatic CT findings.

Serotonergic Antidepressants and Risk for Traumatic Intracranial Bleeding.

Background: Serotonergic antidepressants may predispose to bleeding but the effect on traumatic intracranial bleeding is unknown. Methods: The rate of intracranial bleeding in patients with antidepressant medication was compared to patients not antidepressants in a cohort of patients with acute head injury. This association was examined by using a consecutive cohort of head trauma patients from a Finnish tertiary center emergency department (Tampere University Hospital, Tampere, Finland). All consecutive (2010-2012) adult patients (n = 2,890; median age = 58; male = 56%, CT-positive = 22%, antithrombotic medication users = 25%, antidepressant users = 10%) who underwent head CT due to head trauma in the emergency department were included. Results: Male gender, GCS <15, older age, and anticoagulation were associated with an increased risk for traumatic intracranial bleeding. There were 17.8% of patients not taking antidepressants and 18.3% of patients on an antidepressant who had traumatic intracranial bleeding (p = 0.830). Among patients who were taking antithrombotic medication, 16.6% of the patients not taking antidepressant medication, and 22.5% of the patients taking antidepressant medication, had bleeding (p = 0.239). In a regression analysis, traumatic intracranial hemorrhage was not associated with antidepressant use. Conclusions: Serotonergic antidepressant use was not associated with an increased risk of traumatic intracranial hemorrhage.

Diffusion tensor imaging of the brain in a healthy adult population: Normative values and measurement reproducibility at 3 T and 1.5 T.

BACKGROUND: Diffusion tensor imaging (DTI) is an increasingly used method for investigation of brain white matter integrity in both research and clinical applications. Familiarity with normal variation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and measurement reproducibility is essential when DTI measurements are interpreted in clinical patients. PURPOSE: To establish normal values for FA and ADC in a healthy adult population at 1.5 T and 3 T MRI based on region of interest (ROI) analysis, and to study the inter- and intra-observer reproducibility of the measurements. MATERIAL AND METHODS: Forty healthy volunteers (26 women, 14 men, mean age 38.3, SD 11.6 years) underwent conventional MRI and DTI of the brain, 30 with 3 T and 10 with 1.5 T clinical scanners. ROI-based measurements for FA and ADC values were performed in five different anatomic locations of each hemisphere and in three locations within the corpus callosum. Mean values for FA and ADC for each region were calculated. Inter-observer variation of ROI measurements was evaluated by comparing the results of the two observers, intra-observer variation by repeated measurement of 10 subjects by both observers. RESULTS: The FA values varied considerably between different regions. The highest values were found in the genu and splenium of the corpus callosum and the lowest in the corona radiata, respectively. In general, ADC values showed less variation; the highest values were found in the body of the corpus callosum and the lowest in the corona radiata. The reproducibility of both inter- and intra-observer measurements also varied regionally. The highest agreement was found for the corpus callosum and the lowest for the corona radiata and centrum semiovale. CONCLUSION: In a normal adult population FA and ADC values of the brain white matter show regional variation. The repeatability of the ROI measurements also varies regionally. This regional variability must be acknowledged when these measurements are interpreted in clinical patients.

Characterizing the type and location of intracranial abnormalities in mild traumatic brain injury.

OBJECTIVEThe incidence of intracranial abnormalities after mild traumatic brain injury (TBI) varies widely across studies. This study describes the characteristics of intracranial abnormalities (acute/preexisting) in a large representative sample of head-injured patients who underwent CT imaging in an emergency department.METHODSCT scans were systematically analyzed/coded in the TBI Common Data Elements framework. Logistic regression modeling was used to quantify risk factors for traumatic intracranial abnormalities in patients with mild TBIs. This cohort included all patients who were treated at the emergency department of the Tampere University Hospital (between 2010 and 2012) and who had undergone head CT imaging after suffering a suspected TBI (n = 3023), including 2766 with mild TBI and a reference group with moderate to severe TBI.RESULTSThe most common traumatic lesions seen on CT scans obtained in patients with mild TBIs and those with moderate to severe TBIs were subdural hematomas, subarachnoid hemorrhages, and contusions. Every sixth patient (16.1%) with mild TBI had an intracranial lesion compared with 5 of 6 patients (85.6%) in the group with moderate to severe TBI. The distribution of different types of acute traumatic lesions was similar among mild and moderate/severe TBI groups. Preexisting brain lesions were a more common CT finding among patients with mild TBIs than those with moderate to severe TBIs. Having a past traumatic lesion was associated with increased risk for an acute traumatic lesion but neurodegenerative and ischemic lesions were not. A lower Glasgow Coma Scale score, male sex, older age, falls, and chronic alcohol abuse were associated with higher risk of acute intracranial lesion in patients with mild TBI.CONCLUSIONSThese findings underscore the heterogeneity of neuropathology associated with the mild TBI classification. Preexisting brain lesions are common in patients with mild TBI, and the incidence of preexisting lesions increases with age. Acute traumatic lesions are fairly common in patients with mild TBI; every sixth patient had a positive CT scan. Older adults (especially men) who fall represent a susceptible group for acute CT-positive TBI.

Who Gets Head Trauma or Recruited in Mild Traumatic Brain Injury Research?

Mild traumatic brain injury (mTBI) is a public health problem. Outcome from mTBI is heterogeneous in part due to pre-injury individual differences that typically are not well described or understood. Pre-injury health characteristics of all consecutive patients (n=3023) who underwent head computed tomography due to acute head trauma in the emergency department of Tampere University Hospital, Finland, between August 2010 and July 2012 were examined. Patients were screened to obtain a sample of working age adults with no pre-injury medical or mental health problems who had sustained a "pure" mTBI. Of all patients screened, 1990 (65.8%) fulfilled the mTBI criteria, 257 (8.5%) had a more severe TBI, and 776 (25.7%) had a head trauma without obvious signs of brain injury. Injury-related data and participant-related data (e.g., age, sex, diagnosed diseases, and medications) were collected from hospital records. The most common pre-injury diseases were circulatory (39.4%-43.2%), neurological (23.7%-25.2%), and psychiatric (25.8%-27.5%) disorders. Alcohol abuse was present in 18.4%-26.8%. The most common medications were for cardiovascular (33.1%-36.6%), central nervous system (21.4%-30.8%), and blood clotting and anemia indications (21.5%-22.6%). Of the screened patients, only 2.5% met all the enrollment criteria. Age, neurological conditions, and psychiatric problems were the most common reasons for exclusion. Most of the patients sustaining an mTBI have some pre-injury diseases or conditions that could affect clinical outcome. By excluding patients with pre-existing conditions, the patients with known risk factors for poor outcome remain poorly studied.

Necessity of monitoring after negative head CT in acute head injury.

OBJECTIVE: The main objective of this study was to evaluate the incidence of delayed complications in acute head injury (HI) patients with an initial normal head computed tomography (CT). MATERIALS AND METHODS: This retrospective study included 3023 consecutive patients who underwent head CT due to an acute HI at the Emergency Department (ED) of Tampere University Hospital (August 2010-July 2012). Regardless of clinical injury severity, the patients with a normal head CT were selected (n=2444, 80.9%). The medical records of these patients were reviewed to identify the individuals with a serious clinically significant complication related to the primary HI. The time window considered was the following 72h after the primary head CT. A repeated head CT in the hospital ward, death, or return to the ED were indicative of a possible complication. RESULTS: The majority (n=1811, 74.1%) of the patients with a negative head CT were discharged home and 1.1% (n=27) of these patients returned to ED within 72h post-CT. A repeated head CT was performed on 12 (44.4%) of the returned patients and none of the scans revealed an acute lesion. Of the 632 (25.9%) CT-negative patients admitted to the hospital ward from the ED, a head CT was repeated in 46 (7.3%) patients within 72h as part of routine practice. In the repeated CT sample, only one (0.2%) patient had a traumatic intracranial lesion. This lesion did not need neurosurgical intervention. The overall complication rate was 0.04%. CONCLUSION: In the present study, which includes head injuries of all severity, the probability of delayed life-threatening complications was negligible when the primary CT scan revealed no acute traumatic lesions.

Sport concussion assessment tool 2 in a civilian trauma sample with mild traumatic brain injury.

The aim of the study was to evaluate the validity of the Sport Concussion Assessment Tool-Second Edition (SCAT2) in patients with acute mild traumatic brain injuries (mTBIs) in a civilian trauma setting. In addition, the SCAT2 was compared to the Military Acute Concussion Evaluation (MACE). All the participants of the study were prospectively recruited from the emergency department of Tampere University Hospital (Tampere, Finland). Patients (n=49) between the ages of 18 and 60 years, with no premorbid medical or psychiatric conditions, who met the World Health Organization criteria for mTBI, were enrolled. Trauma controls (n=33) were recruited using similar study criteria. The main measures of the study consisted of SCAT2, MACE, and mTBI severity markers, including neuroimaging (computed tomography and conventional magnetic resonance imaging [MRI]), and 1-month clinical outcomes (postconcussion syndrome diagnosis and return to work status). The scoreable components of the SCAT2 performed variably across five dimensions of validity (diagnostic, criterion, divergent, predictive, and responsiveness). The Standardized Assessment of Concussion component reasonably discriminated mTBI patients from controls, was associated with MRI lesions, improved over time, and predicted return to work. Symptom scores differentiated patients with mTBIs from controls, and elevated initial symptom scores in patients with mTBI were associated with a greater risk of persistent postconcussion symptoms. The SCAT2 was superior to the MACE. The SCAT2 appears useful for detecting acute mTBI-related symptoms and cognitive impairment, refining prognosis, and monitoring recovery.

Who gets recruited in mild traumatic brain injury research?

Selection bias, common in traumatic brain injury research, limits the clinical usefulness and generalizability of study findings. The purpose of this study was to examine the effect of different inclusion and exclusion criteria on patient enrollment, and the implications for generalizability, in a mild traumatic brain injury (MTBI) study. The study was conducted at the emergency department (ED) of Tampere University Hospital. Our aim was to study outcome from MTBI in patients who do not have pre-existing conditions or other confounding factors. For this, all consecutive patients with acute head trauma (n=1344) were screened. The study design included three inclusion criteria and nine exclusion criteria. The World Health Organization Collaborating Center for Neurotrauma Task Force criteria for MTBI were used. Of all patients screened, 934 (69.5%) fulfilled the MTBI criteria. For those fulfilling the MTBI criteria, various inclusion and exclusion criteria were applied in order to yield those eligible for the outcome study. Applying these criteria excluded 95.1% of MTBI patients, leaving only 46 patients in the final sample. The final sample and the excluded patients with MTBI significantly differed in age, mechanism of injury, and injury severity characteristics. Many studies recruit fundamentally biased samples that are not generalizable to the population of persons who sustain an MTBI. Studying carefully selected samples is often necessary to address specific research questions, but such studies have serious limitations in terms of translating research findings into clinical practice.