Simultaneous head and facial computed tomography scans for assessing facial fractures in patients with traumatic brain injury

IntroductionPatients with traumatic brain injury (TBI) may have concomitant facial fractures. While most head injury patients receive head computed tomography (CT) scans for initial evaluation, the objective of our study was to investigate the value of simultaneous facial CT scans in assessing facial fractures in patients with TBI.MethodsFrom January 1, 2015 to December 31, 2015, 1649 consecutive patients presenting to our emergency department (ED) with a TBI who received CT scans using the protocol for head and facial bones were enrolled. The clinical data and CT images were reviewed via a standardized format.ResultsIn our cohort, 200 patients (12.1%) had at least one facial fracture shown on the CT scans. Patients with facial fractures were more likely to have initial loss of consciousness (ILOC; p < 0.001), a Glasgow coma scale of 8 or less (p < 0.001), moderate or severe degrees of head injury severity scale (p < 0.001), positive physical examination findings (p < 0.001), and positive CT cranial abnormalities (p < 0.001). A total of 166 (83.0%) patients with facial fractures required further facial CT scans instead of conventional head CT scans alone. Surgical intervention was mandatory in 73 (44.0%) of the 166 patients, who more frequently exhibited fractures of the lower third of the face (p < 0.001) and orbital fractures (p = 0.019).ConclusionsTBI patients with risk factors may have a higher probability of concomitant facial fractures. Fractures of the lower third of the face and orbit are easily overlooked in routine head CT scans but often require surgical intervention. Therefore, simultaneous head and facial CT scans are suggested in selected TBI patients.     

Dynamic perfusion computerized tomography in cerebral vasospasm following aneurysmal subarachnoid hemorrhage: a comparison with technetium-99m-labeled ethyl cysteinate dimer-single-photon emission computerized tomography

OBJECT: The aim of this study was to correlate cerebral blood flow (CBF) and mean transient time (MTT) measured on dynamic perfusion computerized tomography (CT) with CBF using (99m)Tc ethyl cysteinate dimer-single-photon emission computerized tomography (SPECT) in patients with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). METHODS: Thirty-five patients with vasospasm following aneurysmal SAH (12 men and 23 women with a mean age of 49.3 +/- 10.1 years) underwent imaging studies; thus, 35 perfusion CT scans and 35 SPECT images were available for comparison. The CBF and MTT values in 12 different brain regions were defined relative to the interhemispheric occipital cortex values using perfusion CT scans and were compared with qualitative relative (rel)CBF estimated on SPECT images. In brain regions with normal, mild (relCBF 71-85%), moderate (relCBF 50-70%), and severe (relCBF < 50%) hypoperfusion on SPECT, the mean relCBF values measured on perfusion CT were 1.01 +/- 0.08, 0.82 +/- 0.22, 0.6 +/- 0.15, and 0.32 +/- 0.08, respectively (p < 0.0001); the mean relMTT values were 1.04 +/- 0.14, 1.4 +/- 0.31, 2.16 +/- 0.46, and 3.3 +/- 0.54, respectively (p < 0.0001). All but one brain region (30 regions) with severe hypoperfusion on SPECT images demonstrated relCBF values less than 0.6 and relMTT values greater than 2.5 on perfusion CT scans. CONCLUSIONS: Relative CBF and MTT values on perfusion CT showed a high concordance rate with estimated relCBF on SPECT in patients with vasospasm following aneurysmal SAH. Given its logistical advantages, perfusion CT may be a valuable method of assessing perfusion abnormality in the acute setting of vasospasm and in patients with an unstable condition following aneurysmal SAH.     

Mild head injury: a plea for routine early CT scanning.

We reviewed the records of 1538 mild head injury patients admitted during a 4 1/2-year period to the Southern New Jersey Regional Trauma Center. All patients had experienced brief loss of consciousness or amnesia, but had a normal or near normal neurologic examination on admission, with Glasgow Coma Scale (GCS) scores of 13-15 and no focal neurologic deficit. Routine urgent cranial CT scans were obtained on all patients, and correlations between skull fractures and intracranial lesions investigated. Two hundred sixty-five patients (17.2%) harbored 340 lesions on CT scans, of which 131 were fractures and 209 were intracranial abnormalities. Fifty-eight patients needed surgery for their intracranial lesions; 23 of them had no skull fractures. None of the 1339 patients without CT evidence of intracranial lesions deteriorated under observation. We conclude that clinical observation with or without skull x-ray films is inadequate to rule out potentially dangerous intracranial lesions in apparently mild head injuries. If there is a history of loss of consciousness or amnesia, an immediate CT scan is indicated. If the results of the CT scan are normal and there are no other indications for admission, these patients may be safely discharged.     

Detecting traumatic brain lesions in children: CT versus MRI versus susceptibility weighted imaging (SWI)

Cranial CT scans are at the center of decision making in brain injuries in children because of their speed and ability to detect surgically relevant lesions. However, alternative techniques, such as conventional MRI may have advantages in terms of radiation exposure and sensitivity to detect brain injury. Susceptibility-weighted imaging (SWI), a relatively novel MRI sequence, shows promise in terms of its sensitivity in detecting hemorrhagic lesions; however, its clinical potential remains uncertain. In this observational study of children (5-16 years of age) with traumatic brain injury (TBI) at a tertiary pediatric emergency department (ED) we compared the ability of detecting traumatic brain lesions on acute CT and MRI/SWI ～ 5 weeks post-injury based on detecting the presence or absence, extent, and type of traumatic brain lesions. We analyzed the results of 76 patients (53 male) after TBI (mean age 10.24 ± 2.50 years, range 5.75-14.67 years). Glasgow Coma Score was 13-15 in 54 patients (71%), 9-12 in 13 patients (17%) and <8 in 9 patients (12%). CTs were completed in the ED; MRI and SWI were completed at a mean of 36.11 ± 15.75 days post-injury. Detection of any lesions occurred on CT scan in 68%, on MRI in 54%, and on SWI in 86% of cases, and SWI detected additional lesions 30% of the time compared to CT and MRI. SWI may be more sensitive in detecting traumatic lesions than CT or MRI. This may be important for the ongoing management of TBIs and their prognosis.     

Radionuclide imaging for hyperparathyroidism (HPT): which is the best technetium-99m sestamibi modality?

BACKGROUND: To determine the utility of available radionuclide imaging modalities for preoperative parathyroid localization, we compared the accuracy of 4 types of technetium-99m ((99)Tc) sestamibi-based scans. METHODS: Over 5 years, 833 patients with sporadic primary hyperparathyroidism underwent either (99)Tc-sestamibi with planar views (Planar; n = 138); sestamibi single photon emission computed tomography (SPECT; n = 165); SPECT with thyroid (123)I-subtraction phase (SPECT/(123)I; n = 350); or SPECT combined with conventional CT (SPECT/CT; n = 180). The accuracy of each modality was determined on the basis of intraoperative parathyroid pathology, defined as single adenoma or multigland disease. RESULTS: Planar scans had significantly more false negatives (no tumor visualized) than SPECT-based scans (P < 0.01), but positive predictive values were similar. A false-negative scan was present in 38% of Planar scans, 27% SPECT, 4% SPECT/(123)I, and 17% SPECT/CT, with single adenoma found at operation in 77%, 64%, 53%, and 74%, respectively. When a scan had a single focus of uptake, SA was found at that location in 77%, 85%, 68%, and 87%, respectively. SPECT, SPECT/(123)I, and SPECT/CT did not significantly reduce the false-positive rate. CONCLUSIONS: We recommend obtaining multiplanar SPECT-based imaging, which offers 3-dimensional localization and improved detection of parathyroid tumors when compared with Planar scans. A negative scan did not predict multigland disease.     

Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia; measurement of cerebral blood volume (CBV) with 99mTc-RBC SPECT

To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with 99mTc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by 133Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor complete stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with 99mTc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with 133Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r = -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with 133Xe SPECT and 99mTc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease.     

Comparison of cerebral blood flow in computed tomographic hypodense areas of the brain in head-injured patients

OBJECTIVE: Hypodense lesions identified on computed tomographic (CT) scans are often assumed to indicate ischemia. The purpose of this study was to investigate regional cerebral blood flow (rCBF) in hypodense areas of the brain after severe traumatic brain injury. METHODS: CBF was measured by stable xenon-enhanced CT scans. Hypodense areas were identified, and rCBF values as well as CT density were averaged for the region. RESULTS: Thirty (60%) of the 50 patients had a total of 45 hypodense regions, which were associated with either contusion (n = 30) or areas of infarction (n = 15). rCBF in the hypodense regions was variable, ranging from a low of 3.3 to a high of 72.5 ml/100 g/min. The cause of the lesion was the major factor associated with the level of rCBF. Although the average decrease in CT density was similar for the two types of lesions, the average rCBF was significantly lower and the difference in rCBF between the lesion and the contralateral side was greater when the hypodense lesion was associated with a contusion. A critical reduction in rCBF (<20 ml/100 g/min) was found in 19 (63%) of the hypodense regions associated with contusions but in only 4 (27%) of those from areas of infarction. CONCLUSION: Hypodensity on plain CT scans does not always indicate reduction in CBF. This association was found more commonly when the low-density area was associated with a contusion. In hypodense areas associated with infarction, rCBF was variable and not commonly in the ischemic range at the time the CBF measurement was obtained.     

Utility of neurosurgical consultation for mild traumatic brain injury

Trauma patients presenting with a Glasgow Coma Scale (GCS) score of 14-15 are considered to have mild traumatic brain injury (TBI) with overall good neurologic outcomes. Current practice consists of initial stabilization, followed by a head CT, and neurosurgical consultation. Aside from serial neurologic examinations, patients with a GCS of 15 rarely require neurosurgical intervention. In this study, we examined the added value of neurosurgical consultation in the care of patients after TBI with a GCS of 15. We retrospectively reviewed the medical records of patients presenting after blunt trauma with an abnormal head CT and GCS of 15 between January 2004 and January 2005. Patients with a normal head CT and <48 hours hospital stay were excluded. Data included demographics, mechanisms of injury, Injury Severity Score, the radiologists' dictated interpretations of the head CT, and neurosurgical interventions. Fifty-six patients met the inclusion criteria. The mean age was 41+/-2.3 years, and the mean Injury Severity Scores was 10.2 +/-0.6. Mechanisms of injury included 64 per cent motor vehicle crash, 16 per cent motorcycle crash, 13 per cent fall, and 7 per cent all-terrain vehicle crash. The initial CT scans showed 43 per cent parenchymal contusions, 38 per cent subarachnoid hemorrhage, 14 per cent subdural hematomas, and 5 per cent epidural hematomas. All patients received a routine follow-up head CT, and 16 per cent showed changes (five improved and four were worse compared with initial CT scans). None of these patients received a neurosurgical intervention, and two were transferred to a rehabilitation service. In this era of limited resources, trauma patients who present with a GCS score of 15 after mild TBI can be safely managed without neurosurgical consultation, even in the presence of an abnormal head CT scan.     

SPECT显像在脑损伤后症候群中的应用

目的探查SPECT脑血流灌注显像和CT、MRI脑显像在脑损伤后症候群患者中的应用价值.方法 126例有脑损伤后症候群的患者均用99mTc-ECD行SPECT脑血流灌注显像;同时,其中80例行CT显像,其余46例行MRI显像.结果 126例患者中,SPECT检查阳性113例,阳性率为89.7%;CT和MRI检查阳性52例,阳性率为41.3%,二者差异明显P＜0.01.结论 SPECT脑血流灌注显像检查脑损伤后症候群的灵敏度高于CT或MRI,而CT或MRI 在定位和微小病灶探查上优于SPECT,临床运用中应进行有机地结合.     

Indications for CT scanning in mild traumatic brain injury: A cost-effectiveness study

BACKGROUND: There is considerable uncertainty about the indications for cranial computed tomography (CT) scanning in patient with minor traumatic brain injury (TBI). This analysis involves an evidence-based comparison of several strategies for selecting patients for CT with regard to effectiveness and cost. METHODS: We performed a structured literature review of mild traumatic brain injury and constructed a cost-effectiveness model. The model estimated the impact of missed intracranial lesions on longevity, quality of life and costs. Using a 20-year-old patient for primary analysis, we compared the following strategies to screen for the need to perform a CT scan: observation in the emergency department or hospital floor, skull radiography, Selective CT based on the presence of additional risk factors and scanning all. RESULTS: Outcome measures for each strategy included average years of life, quality of life and costs. Selective CT and the CT All policy performed significantly better than the alternatives with respect to outcome. They were also less expensive in terms of total direct health care costs, although the differences did not reach statistical significance. The model yielded similar, but smaller, differences between the selective imaging and other strategies when run for older patients. CONCLUSIONS: Although the incidence of intracranial lesions, especially those that require surgery, is low in mild TBI, the consequences of delayed diagnosis are forbidding. Adverse outcome of an intracranial hematoma is so costly that it more than balances the expense of CT scans. In our cost-effectiveness model, the liberal use of CT scanning in mild TBI appears justified.     

Added value of SPECT/CT in patients suspected of having bone infection: preliminary results

AIM: We evaluated the contribution of SPECT/CT as an adjunct to combined three-phase bone scintigraphy (planar and SPECT) for diagnosing and localizing bone infection. Subsequently, the diagnostic performance of SPECT/CT was compared to visual fusion of SPECT with data of additional CT, X-ray, or MRI studies (SPECT + CT/X-ray/MRI). MATERIALS AND METHODS: Thirty-one patients suspected of bone infection, presenting pathological findings on triple-phase bone scintigraphy, underwent additional SPECT/CT. The SPECT/CT-technology combines the acquisition of SPECT and CT data with the same imaging device enabling perfect overlay of anatomical and functional images. (99m)Tc-DPD was used as radiopharmaceutical in all patients. For data analysis findings of bone scintigraphy (planar scans as well as SPECT) were categorized as positive, negative, or equivocal for the presence of osteomyelitis. In a second step, they were compared with SPECT/CT and SPECT + CT/X-ray/MRI with respect to localization and classification of lesions. Validation was achieved by surgery, biopsy, or by clinical follow up over at least 9 months including microbiological and radiological findings. RESULTS: Three-phase bone scan (incl. SPECT) correctly classified 7 lesions as positive and 11 lesions as negative for osteomyelitis. Six scans were interpreted false positive, two false negative, and five as equivocal. Rating the latter as positive for osteomyelitis, sensitivity of bone scan was (78%), specificity (50%). SPECT/CT was true positive in 7 patients, and true negative in 19. There were two false positive and two false negative findings, one scan was equivocal (sensitivity 78%, specificity 86%). Definition of anatomical localization of inflammatory foci was much easier by SPECT/CT due to better depiction of underlying anatomical details. SPECT + CT/X-ray/MRI yielded the highest sensitivity (100% compared to 78% of SPECT/CT), if equivocal findings (5/31 compared to 1/31 for SPECT/CT) are rated as true positive for osteomyelitis. Among radiological techniques, MRI (2 x FP) and CT (2 x FN) proved equal and expectedly superior to X-ray in delivering the correct diagnosis. CONCLUSION: SPECT/CT improves the diagnostic performance of three-phase bone scan for osteomyelitis by avoiding false positive or equivocal results. An additional benefit over visual fusion of SPECT with X-ray, CT, or MRI studies could not be confirmed in our study.     

Role of Routine Repeat Head CT for Pediatric Patients under 2 Years Old with Mild-to-moderate Traumatic Brain Injury

Repeat head computed tomography (RHCT) is common and routine for pediatric traumatic brain injury (TBI) patients. In mild (Glasgow Coma Scale; GCS 13–15) to moderate (GCS 9–12) TBI, recent studies have shown that RHCT without clinical deterioration does not alter management. However, the effectiveness of routine RHCT for pediatric TBI patients under 2 years has not been investigated. This study aims to investigate whether routine RHCT changes management in mild-to-moderate TBI patients under 2 years. We performed a retrospective review at the emergency department of the National Center for Child Health and Development between January 2015 and December 2019. Mild-to-moderate TBI patients under 2 years with an acute intracranial injury on initial head CT scan and receiving follow-up CT scans were included. Mechanism, severity of TBI, indication for RHCT, and their findings were listed. Study outcome was intervention based on the findings of RHCT. Intervention was defined as intubation, ICP monitor placement, or neurosurgery. We identified 50 patients who met inclusion criteria and most patients (48/50) had mild TBI. The most common mechanism was ‘fall’ (68%). Almost all RHCT was routine and the overall incidence of radiographic progression on RHCT was 12%. RHCT without clinical deterioration did not lead to intervention, although one patient with moderate TBI required intervention due to radiographic progression with clinical symptoms. Our study showed that routine RHCT without clinical deterioration for mild TBI patients under 2 years may not alter clinical management. We suggest that RHCT be considered when there is clinical deterioration such as decrease in GCS.     

Progressive brain injury

The aim of this study was to evaluate the clinical manifestations and prognostic factors of progressive brain injury following trauma. We reviewed the records of 779 patients with head injury who had an admission Glasgow Coma Scale of 9 or more; 70 (7.0%) developed progressive brain injury as evidenced on serial CT scans. Of these 70 patients, 19 (27.1%) had a subdural hematoma, 19 (27.1%) an epidural hematoma, 16 (22.9%) a cerebral contusion, 13 (18.6%) an intracerebral hematoma, and 3 (4.3%) a diffuse brain swelling. Three months after injury, 36 (51.4%) patients died, 2 (2.9%) were left in a vegetative state and 23 (32.9%) had a favorable outcome. The appearance of progressive brain injury was associated with patient age, admission Glasgow Coma Scale, injury mechanisms, skull fracture and hemorrhagic lesions on the initial CT scan. Patients with the extracerebral lesions deteriorated 4 hours after injury, whereas those with intracerebral lesions deteriorated 8 hours after injury. The outcome based on Glasgow Outcome Scale was significantly associated with age, type of intracranial lesion, Glasgow Coma Scale following deterioration, the mechanism of injury and surgical treatment. It is concluded that early repeated CT scan is indicated in patients with risk factors of developing progressive brain injury.     

Tc HMPAO SPECT in persistent post concussion syndrome after mild head injury comparison with MRI CT

The purposes of this study were 1 to determine the prevalence of abnormal mTc HMPAO SPECT scans in patients suffering persistent post concussive syndrome PPCS after mild closed head injury CHI 2 to compare SPECT with structural neuroimaging MRI and CT in patients with mild CHI and 3 to investigate correlations between SPECT and clinical data obtained from the patient sample neuropsychological testing demographics psychiatric diagnoses Forty three patients were included SPECT was read as abnormal in 53 of patients and showed a total of 37 lesions while MRI was read as abnormal in 9 and CT scan in only 4 6 of patients after mild CHI SPECT appears to be more sensitive in detecting cerebral abnormalities after mild CHI especially in patients with PPCS symptoms than either CT or MRI No statistically significant relationship was found between SPECT scan abnormalities and age past psychiatric history history of substance abuse or history of multiple CHI Education level did differ between patients with normal and abnormal SPECT Current neuropsychiatric symptoms did not seem to have any impact on the results of SPECT scan     

Hemiballismus following closed head injury

Received 19 January 1995; accepted 15 April 1995 Movement disorders are relatively rare after closed head injury (CHI), but when present they can be unrecognized if clinicians are not aware of their occurrence. We are presenting a case of hemiballismus which was not recognized over 3 years and was labelled as malingering or as psychosomatic. The symptoms have responded significantly to pharmacological intervention. The SPECT scan of the brain showed the lesions in the subthalamic areas while MRI, CT scans of brain and EEGs were reported normal. It is concluded that one should be aware of the existence of movement disorders after mild to moderate CHI, and that SPECT scan of the brain should be considered if a patient is symptomatic and other neuroimaging studies prove 'normal'.     

Post-operative expansion of hemorrhagic contusions after unilateral decompressive hemicraniectomy in severe traumatic brain injury

Decompressive hemicraniectomy is commonly performed in patients with traumatic brain injury (TBI) with diffuse brain swelling or refractory raised intracranial pressure. Expansion of hemorrhagic contusions in TBI patients is common, but its frequency following decompressive hemicraniectomy has not been well established. The aim of this retrospective study was to determine the rate of hemorrhagic contusion expansion following unilateral hemicraniectomy in severe TBI, to identify factors associated with contusion expansion, and to examine whether contusion expansion is associated with worsened clinical outcomes. Computed tomography (CT) scans of 40 consecutive patients with non-penetrating TBI who underwent decompressive hemicraniectomy were analyzed. Hemorrhagic contusion volumes were measured on initial, last pre-operative, and first post-operative CT scans. Mortality and 6-month Glasgow Outcome Scale (GOS) score were recorded. Hemorrhagic contusions of any size were present on the initial head CT scan in 48% of patients, but hemorrhagic contusions with a total volume of >5 cc were present in only 10%. New or expanded hemorrhagic contusions of >or=5 cc were observed after hemicraniectomy in 58% of patients. The mean volume of increased hemorrhage among these patients was 37.1+/-36.3 cc. The Rotterdam CT score on the initial head CT was strongly associated with the occurrence and the total volume of expanded hemorrhagic contusions following decompressive hemicraniectomy. Expanded hemorrhagic contusion volume greater than 20 cc after hemicraniectomy was strongly associated with mortality and poor 6-month GOS even after controlling for age and initial Glasgow Coma Scale (GCS) score. Expansion of hemorrhagic contusions is common after decompressive hemicraniectomy following severe TBI. The volume of hemorrhagic contusion expansion following hemicraniectomy is strongly associated with mortality and poor outcome. Severity of initial CT findings may predict the risk of contusion expansion following hemicraniectomy, thereby identifying a subgroup of patients who might benefit from therapies aimed at augmenting the coagulation system.     

Diffusion-weighted magnetic resonance imaging improves outcome prediction in adult traumatic brain injury

In patients with traumatic brain injury (TBI), diffuse axonal injury (DAI) accounts for a significant amount of parenchymal injury. Diffusion weighted magnetic resonance imaging (DWI) is known to be sensitive for detecting visible DAI lesions. We focused on detection of non-visible, quantifiable diffusion changes in specific normal-appearing brain regions, using apparent diffusion coefficient (ADC) maps. Thirty-seven adults with TBI were compared to 35 age-matched control patients. DWI was performed and ADC maps were generated. Thirty-one regions of interest (ROI) were manually drawn on ADC maps and ADC values extracted. Brain ROIs were categorized into five zones: peripheral gray matter, peripheral white matter, deep gray matter, deep white matter, and posterior fossa. ADC results were compared with the severity of injury based on the admission Glasgow Coma Scale (GCS 3-8; severe; GSC 9-15 mild/moderate) and with long-term outcome (6-12 months after injury) using the Glasgow Outcome Scale (GOS 1-3, unfavorable; GOS: 4-5, favorable) score. Mean ADC values in all five brain zones were significantly different between TBI subjects and controls (p相似文献   

Evaluation of regional cerebral blood flow using single photon emission tomography for the selection of patients for local fibrinolytic therapy of acute cerebral embolism

To clarify the indications for local fibrinolytic therapy for acute cerebral embolism, correlation among initial regional cerebral blood flow (rCBF) abnormalities, recanalization timing, and computed tomographic scan (CT) findings two days later were evaluated in 17 cases. All cases included had embolic occlusion of middle cerebral or internal carotid arteries which showed no abnormal findings on initial CT corresponding to the acute events but did show abnormal CBF reduction on initial single photon emission computed tomography (SPECT). Relative rCBF was evaluated as the percentage radioisotope counts in the region of interest (ROI) of the affected side against the corresponding ROI in the unaffected contralateral side. Within 6 hours from onset, there was a tendency towards reversed time dependent tolerance of cortical infarction with residual relative rCBE. Hemorrhagic transformation was observed in one case whose relative rCBF was 35% or less. In 10 patients whose occluded arteries were not recanalized within 6 hours, cortical areas with residual relative rCBF of 70% or more did not develop infarction. In conclusions, a pre-therapeutic rCBF study using SPECT is considered to be mandatory: cases with moderate ischemia involving the cortex with residual relative rCBF of between 35% and 70% may be good candidates for local fibrinolytic therapy.     

The value of computed tomographic scans in patients with low-risk head injuries

The determination that a particular head injury is "mild" or "low-risk" is usually made on clinical grounds. Observation at home or in the hospital has been the usual treatment for such patients. A recent report of excessive mortality among these patients with low-risk head injuries in some hospital settings suggests the need for improvement in diagnostic criteria. Our study included 658 patients admitted to Cooper Hospital for a mild head injury, who had a Glasgow Coma Scale score of 13 to 15 on admission, and who experienced a brief loss of consciousness or amnesia after the injury. Their records and cranial computed tomographic (CT) scans on admission were reviewed to determine their subsequent course. In 18% of patients abnormalities were seen on the initial CT scan and 5% required surgery. Among the 62 patients with a Glasgow Coma Scale score of 13, 40% had abnormalities on the CT scan and 10% required surgery. None of the 542 patients with normal CT scans on admission showed subsequent deterioration and none needed surgery. These figures suggest that history and physical examination alone are not adequate to assess head injury or severity of risk and that the addition of a CT scan greatly improves patient assessment. Abnormalities on CT scans are so common in patients with a Glasgow Coma Scale score of 13 that head injuries in these patients should be classified as "moderate" rather than "mild" in severity and risk. Patients with normal CT scans should be considered for observation at home, allowing hospital personnel to devote full attention to the more seriously injured patients.     

Neuroanatomic basis of impaired self-awareness after traumatic brain injury: findings from early computed tomography

BACKGROUND: Impaired self-awareness (ISA) is common among patients with severe traumatic brain injury (TBI) and contributes to poorer functional outcome. There is keen interest in improving the understanding of this disorder as the neuroanatomic substrate of posttraumatic ISA is poorly understood. OBJECTIVE: Determine whether (1) greater number of brain lesions, (2) greater volume of right hemisphere lesions, or (3) greater volume of frontal lesions is associated with greater levels of ISA after TBI. DESIGN: Prospective, observational study. PARTICIPANTS: Ninety-one TBI admissions to one of 2 National Institute on Disability and Rehabilitation Research TBI Model System (TBIMS) programs. Subjects met TBIMS inclusion criteria plus (1) resolution of posttraumatic amnesia (PTA) prior to rehabilitation discharge and (2) initial postinjury computerized tomography (CT) scan available as a hard copy and as an electronic file. METHODS: CT scan lesions outlined by a board-certified neuroradiologist were measured using NIH Image, and resulting calculated lesion volumes/scan variables compared against demographic characteristics, TBI severity variables, and ISA variables measured by the Awareness Questionnaire (AQ) at the time of PTA resolution. RESULTS: Most subjects (78%) had at least 1 lesion on emergent CT, and contusion volumes varied in all regions of interest. Patients rated their functioning as more intact on the AQ than ratings of treating clinicians, consistent with ISA. Greater injury severity was associated with a greater degree of ISA. Multivariable linear regression revealed that, after adjustment for other predictors, the number of brain lesions was predictive of degree of ISA. Right hemisphere contusion or frontal lobe contusion volumes, however, were not predictive of degree of ISA. CONCLUSIONS: ISA was significantly associated with the number, but not with location or volume of focal lesions early after TBI. Posttraumatic ISA may reflect disruption in the integrated operation of broadly distributed neural networks, with lesion burden in any specific region being less relevant than disruption across multiple regions. Further imaging research is warranted to confirm these findings and to provide insight into the distributed networks required for self-awareness.