Outcome prediction in moderate and severe traumatic brain injury: a focus on computed tomography variables.

BACKGROUND: With this study we aimed to design validated outcome prediction models in moderate and severe traumatic brain injury (TBI) using demographic, clinical, and radiological parameters. METHODS: Seven hundred consecutive moderate or severe TBI patients were included in this observational prospective cohort study. After inclusion, clinical data were collected, initial head computed tomography (CT) scans were rated, and at 6 months outcome was determined using the extended Glasgow Outcome Scale. Multivariate binary logistic regression analysis was applied to evaluate the association between potential predictors and three different outcome endpoints. The prognostic models that resulted were externally validated in a national Dutch TBI cohort. RESULTS: In line with previous literature we identified age, pupil responses, Glasgow Coma Scale score and the occurrence of a hypotensive episode post-injury as predictors. Furthermore, several CT characteristics were associated with outcome; the aspect of the ambient cisterns being the most powerful. After external validation using Receiver Operating Characteristic (ROC) analysis our prediction models demonstrated adequate discriminative values, quantified by the area under the ROC curve, of 0.86 for death versus survival and 0.83 for unfavorable versus favorable outcome. Discriminative power was less for unfavorable outcome in survivors: 0.69. CONCLUSIONS: Outcome prediction in moderate and severe TBI might be improved using the models that were designed in this study. However, conventional demographic, clinical and CT variables proved insufficient to predict disability in surviving patients. The information that can be derived from our prediction rules is important for the selection and stratification of patients recruited into clinical TBI trials.

Essential features of Chiari II malformation in MR imaging: an interobserver reliability study--part 1.

PURPOSE: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of morphological features of the malformation on MR images may not always be straightforward. In an attempt to select those features that unambiguously characterize the Chiari II malformation, we investigated the interobserver reliability of all its well-known MR features. METHODS: Brain MR images of 79 children [26 presumed to have Chiari II malformation, 36 presumed to have no cerebral abnormalities, and 17 children in whom some Chiari II malformation features might be present; mean age 10.6 (SD 3.2; range, 6-16) years] were blindly and independently reviewed by three observers. They rated 33 morphological features of the Chiari II malformation as present, absent, or indefinable in three planes (sagittal, axial, and coronal). The interobserver reliability was assessed using κ statistics. RESULTS: Twenty-three of the features studied turned out to be unreliable, whereas the interobserver agreement was almost perfect (κ value > 0.8) for nine features (eight in the sagittal plane and one in the axial plane, but none in the coronal plane). CONCLUSIONS: This study presents essential features of the Chiari II malformation on MR images by ruling out the unreliable features. Using these features may improve the assessment of Chiari II malformation in clinical and research settings.

Interobserver reliability and diagnostic performance of Chiari II malformation measures in MR imaging--part 2.

PURPOSE: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of MR images of the malformation is not always straightforward. Morphometric analyses of the extent of Chiari II malformation may improve the assessment. In an attempt to select appropriate morphometric measures for this purpose, we investigated the interobserver reliability and diagnostic performance of several morphometric measures of Chiari II malformation on MR images. METHODS: Brain MR images of 79 children [26 with open spinal dysraphism, 17 with closed spinal dysraphism, and 36 without spinal dysraphism; mean age 10.6 (SD 3.2; range, 6-16) years] were evaluated. All children had been assessed for Chiari II malformation (defined as cerebellar herniation in combination with open spinal dysraphism; n = 23). Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes. The interobserver reliability was assessed by an agreement index (AI = 1 - RRE) and the diagnostic performance by receiver operating characteristic analyses. RESULTS: Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil. Most values differed statistically significantly between children with and without Chiari II malformation. The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance. CONCLUSIONS: Morphometric measures may reliably quantify the morphological distortions of Chiari II malformation on MR images and provide additional tools to assess the severity of Chiari II malformation in clinical and research settings.

Computed tomography and outcome in moderate and severe traumatic brain injury: hematoma volume and midline shift revisited.

Intracranial lesion volume and midline shift are powerful outcome predictors in moderate and severe traumatic brain injury (TBI), and therefore they are used in TBI and computed tomography (CT) classification schemes, like the Traumatic Coma Data Bank (TCDB) classification. In this study we aimed to explore the prognostic value of lesion volume and midline shift in moderate and severe TBI as measured from acute cranial CT scans. Also, we wanted to determine interrater reliability for the evaluation of these CT abnormalities. We included all consecutive moderate and severe TBI patients admitted to our hospital who were aged ≥16 years, over an 8-year period, as part of the prospective Radboud University Brain Injury Cohort Study. Six months post-trauma we assessed outcomes using the Glasgow Outcome Scale-Extended (GOS-E). We analyzed 605 patients and found an association of both lesion volume and midline shift with outcome; increases were associated with a higher frequency of patients with an unfavorable outcome or death. A cut-off value, such as that used in the TCDB CT classification (lesion volume 25 mL and midline shift 5 mm), was not found. The average interrater difference in volume measurement was 6.8 mL, and it was 0.2 mm for the determination of degree of shift. Using lesion volume and midline shift as continuous variables in prognostic models might be preferable over the use of threshold values, although an association of these variables with outcome in relation to other CT abnormalities was not tested. The data provided here will be useful for stratification of patients enrolled in clinical trials of neuroprotective therapies.

(18)F-fluoro-L-thymidine-PET for the evaluation of primary brain tumours in children: a report of three cases.

BACKGROUND: F-fluoro-L-thymidine (FLT) has been shown to be a useful PET tracer in the evaluation of brain tumours in adults. No studies of this modality in children with brain tumours, however, have been published. OBJECTIVE: In this report three children with brain tumours are presented in which FLT-PET was used for different diagnostic purposes, in addition to imaging with MRI and F-fluorodeoxyglucose-PET. The first patient showed that FLT-PET could be helpful in differentiating between infection and malignancy. In the second patient FLT-PET was used for differentiating recurrent disease from radiotherapy effects. In the third patient, in which biopsy was not possible, FLT-PET was used for the characterization of the tumour. CONCLUSION: These patients show that FLT-PET might be a useful modality in different stages of the evaluation of primary brain tumours in children. However, further research to determine the clinical value, relative to MRI and fluorodeoxyglucose-PET, is required before routine implementation of FLT-PET.

The status of the fourth ventricle and ambient cisterns predict outcome in moderate and severe traumatic brain injury.

Computed tomography (CT) of the head has become the diagnostic tool of choice, particularly for moderate and severe traumatic brain injury (TBI). Various CT characteristics are associated with outcome, and may therefore be used as outcome predictors. One of the most prominent predictors appears to be the status of the basal cisterns. This study describes the prognostic value of the appearance of individual cisterns and ventricles in relation to that of the basal cisterns. Further, we determine the interrater and intrarater reliability in the evaluation of the cisterns and ventricles. All consecutive moderate and severe adult TBI patients admitted to our hospital were included in this study as part of the prospective Radboud University Brain Injury Cohort Study (RUBICS). Outcome was assessed at 6 months post-trauma using the Glasgow Outcome Scale-Extended (GOS-E). The predictive value of cisterns and ventricles was determined using multivariate binary logistic regression analysis. We included 126 moderate and 574 severe TBI patients. Absence (complete obliteration), but also compression of the ambient cisterns and/or the fourth ventricle were strongly related to unfavorable outcome and death and emerged as the only significant outcome predictors after multivariate analysis. The assessment of the ambient cisterns and the fourth ventricle had a satisfactory inter- and intrarater reliability (kappa coefficients: 0.80-0.95). We conclude that, because obliteration of the ambient cisterns and the fourth ventricle both are better than the status of the basal cisterns as outcome predictors, they might be used in CT prediction models in cases of moderate and severe TBI.

Outcome prediction in mild traumatic brain injury: age and clinical variables are stronger predictors than CT abnormalities.

Mild traumatic brain injury (mTBI) is a common heterogeneous neurological disorder with a wide range of possible clinical outcomes. Accurate prediction of outcome is desirable for optimal treatment. This study aimed both to identify the demographic, clinical, and computed tomographic (CT) characteristics associated with unfavorable outcome at 6 months after mTBI, and to design a prediction model for application in daily practice. All consecutive mTBI patients (Glasgow Coma Scale [GCS] score: 13-15) admitted to our hospital who were age 16 or older were included during an 8-year period as part of the prospective Radboud University Brain Injury Cohort Study (RUBICS). Outcome was assessed at 6 months post-trauma using the Glasgow Outcome Scale-Extended (GOSE), dichotomized into unfavorable (GOSE score 1-6) and favorable (GOSE score 7-8) outcome groups. The predictive value of several variables was determined using multivariate binary logistic regression analysis. We included 2784 mTBI patients and found CT abnormalities in 20.7% of the 1999 patients that underwent a head CT. Age, extracranial injuries, and day-of-injury alcohol intoxication proved to be the strongest outcome predictors. The presence of facial fractures and the number of hemorrhagic contusions emerged as CT predictors. Furthermore, we showed that the predictive value of a scheme based on a modified Injury Severity Score (ISS), alcohol intoxication, and age equalled the value of one that also included CT characteristics. In fact, it exceeded one that was based on CT characteristics alone. We conclude that, although valuable for the identification of the individual mTBI patient at risk for deterioration and eventual neurosurgical intervention, CT characteristics are imperfect predictors of outcome after mTBI.

MRI of pneumorachis in a newborn infant with open myelomeningocele.

Pneumorachis, or air within the spinal canal, is a very rare radiographic finding, frequently of traumatic origin. A newborn infant with an open lumbosacral myelomeningocele presented with severe paraparesis and an unexpected dysfunction of the brainstem with somnolence, irregular respiration, and motor deficits of the upper extremities. Magnetic resonance imaging revealed hypoplasia of the brainstem and cerebellum and low-signal lesions on T(2)-weighted images at the cervicocranial junction, in the lateral ventricles, and in the spinal canal. Computed tomography confirmed the presence of intracranial and intraspinal air. The air disappeared 2 weeks later according to magnetic resonance imaging, but no clinical improvement occurred, even after 6 months. Pneumorachis and pneumocephalus can occur in newborn infants as an unexpected complication of an open myelomenigocele, with or without signs. The radiographic appearance of intraspinal air on magnetic resonance imaging was not described previously.