Sherman C. Stein

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.

Temporal window of vulnerability to repetitive experimental concussive brain injury.

OBJECTIVE:Repetitive concussive brain injury (CBI) is associated with cognitive alterations and increased risk of neurodegenerative disease. METHODS:To evaluate the temporal window during which the concussed brain remains vulnerable to a second concussion, anesthetized mice were subjected to either sham injury or single or repetitive CBI (either 3, 5, or 7 days apart) using a clinically relevant model of CBI. Cognitive, vestibular, and sensorimotor function (balance and coordination) were evaluated, and postmortem histological analyses were performed to detect neuronal degeneration, cytoskeletal proteolysis, and axonal injury. RESULTS:No cognitive deficits were observed in sham-injured animals or those concussed once. Mice subjected to a second concussion within 3 or 5 days exhibited significantly impaired cognitive function compared with either sham-injured animals (P < 0.05) or mice receiving a single concussion (P < 0.01). No cognitive deficits were observed when the interconcussion interval was extended to 7 days, suggestive of a transient vulnerability of the brain during the first 5 days after an initial concussion. Although all concussed mice showed transient motor deficits, vestibulomotor dysfunction was more pronounced in the group that sustained two concussions 3 days apart (P < 0.01 compared with all other groups). Although scattered degenerating neurons, evidence of cytoskeletal damage, and axonal injury were detected in selective brain regions between 72 hours and 1 week after injury in all animals sustaining a single concussion, the occurrence of a second concussion 3 days later resulted in significantly greater traumatic axonal injury (P < 0.05) than that resulting from a single CBI. CONCLUSION:These data suggest that a single concussion is associated with behavioral dysfunction and subcellular alterations that may contribute to a transiently vulnerable state during which a second concussion within 3 to 5 days can lead to exacerbated and more prolonged axonal damage and greater behavioral dysfunction.

Coagulopathy in traumatic brain injury

Abnormalities in blood coagulation, although quite common after traumatic brain injury (TBI), are of unknown significance. The authors review the clinical and pathophysiological features of this phenomenon and emphasize its origin in disseminated intravascular coagulation. This connection provides a possible explanation for much of the cerebral ischema that accompanies TBI, namely intravascular microthrombosis. The authors’ own research findings support this contention and suggest possible therapeutic avenues.A number of compelling studies demonstrate that DIC is a common and important consequence of TBI. In particular, posttraumatic coagulapathy appears to be linked to secondary cerebral injury. Although the extent of this process has yet to be elucidated fully, coagulation abnormalities are evident soon after trauma. This allows early identification of patients likely to suffer secondary complications and provides an opportunity to evaluate promising agents that may mitigate posttraumatic DIC and related pathologies in these patients. This is an area deserving of more intensive research.

150 Years of Treating Severe Traumatic Brain Injury: A Systematic Review of Progress in Mortality

Considerable effort and resources have been devoted to preserving life in patients with severe closed traumatic brain injury (TBI). We sought to identify temporal trends in mortality rates of these patients from the late 1800s to the present. We searched the literature for articles on severe TBI, abstracting numbers of patients studied, numbers of deaths, and years of patient entry. Mortality rates were calculated for each study, and meta-regression was used to pool data and to test for significant temporal trends. We reviewed 207 case series comprising more than 140,000 cases of severe closed TBI admitted to hospital over a span of almost 150 years. Since the late 1800s mortality has fallen by almost 50%. However, the rate has varied considerably among the four epochs chosen. Between 1885 and 1930, mortality decreased at a rate of 3% per decade. From 1970 to 1990, mortality declined at a rate of 9% per decade. Both changes are significant. There was no observed improvement in mortality between 1930 and 1970, nor is progress evident since 1990. The authors discuss possible reasons for the apparently intermittent progress in TBI survival over time.

Delayed and Progressive Brain Injury in Closed-Head Trauma

The importance of delayed or secondary brain insults in the eventual outcome of closed-head trauma has been documented in experimental models. To understand this phenomenon in the clinical setting, we studied a series of head-injured patients in whom multiple cranial computed tomographic (CT) scans were obtained. Patients whose follow-up CT studies revealed new intracranial lesions or worsening, compared with admission findings, were considered to have delayed cerebral injury. One hundred forty-nine (44.5%) of 337 consecutively studied patients developed delayed brain injury. There were highly significant associations (P < 0.001) between the appearance of delayed cerebral insults and the severity of the initial brain injury, the need for cardiopulmonary resuscitation in the field, the presence of coagulopathy at admission, and subdural hematoma on the initial CT scan. In addition, delayed injury was associated (P < 0.001) with higher mortality, slowed recovery, and poorer outcome at 6 months. Delayed brain injury was not significantly associated with patient age, sex, injury mechanism, associated injury, the need for endotracheal intubation in the field, early talking, CT abnormality other than intracranial hematoma, or type of residual neurological deficits. We used multiple regression analysis to explore the relationship between severity of injury, delayed insults, and outcome. As expected, the severity of the initial brain trauma contributed significantly to neurological outcome. The presence of delayed cerebral injury makes the outcome dramatically worse for each category of initial injury severity. The relationship between initial and secondary brain injury is discussed.

Thromboembolism and delayed cerebral ischemia after subarachnoid hemorrhage: an autopsy study.

OBJECTIVE:Recent findings have cast doubt on vasospasm as the sole cause of delayed cerebral ischemia after subarachnoid hemorrhage. METHODS:We reviewed the medical records of 29 patients who died after subarachnoid hemorrhage. Brain sections were taken from the insula, cingulate gyrus, and hippocampus. Adjacent sections were stained with hematoxylin-eosin and immunostained for thromboemboli. The density (burden) of the latter was calculated blindly and correlated with evidence for ischemia and with the amount of subarachnoid blood. RESULTS:There is a strong correlation between microclot burden and delayed cerebral ischemia. Patients with clinical or radiological evidence of delayed ischemia had mean microclot burdens of 10.0/cm2 (standard deviation [SD], ±6.6); those without had mean burdens of 2.8 (SD, ±2.6), a highly significant difference (P = 0.002). There is also significant association (P = 0.001) between microclot burden and histological evidence of ischemia, with the mean burdens being 10.9 in sections exhibiting severe ischemia and 4.1 in those in which ischemia was absent. Microclot burden is high in patients who died within 2 days of hemorrhage, decreasing on Days 3 and 4. In delayed ischemia, the numbers rise again late in the first week and remain high until after the second week. In contrast, the average clot burden is low in patients dying without developing delayed ischemia. The amount of blood on an individual slide influenced the microclot burden on that slide to a highly significant extent (P < 0.001). CONCLUSION:Thromboembolism after subarachnoid hemorrhage may contribute to delayed cerebral ischemia, which parallels that caused by vasospasm. The pathogenesis of thromboembolism is discussed.

The Head Injury Severity Scale (HISS): a practical classification of closed-head injury

The authors introduce a two-dimensional scale for rating closed-head injury, the Head Injury Severity Scale (HISS). This system is based on a five-interval severity classification (minimal through critical), determined primarily by the initial post-resuscitation Glasgow Coma Scale score. The second dimension is predicated on the presence or absence of complications, appropriate for each severity interval. The outcomes of almost 25,000 patients with head injury encountered at our institution over a 7-year period were evaluated. We discovered that adding a complication dimension to each severity category resulted in significant outcome differences and effectively divided patients into groups with very different risks, prognosis and treatment requirements. The HISS is proposed as a framework on which further research can be done to guide care to predict outcome and to perform audits on head-injured patients.

Relationship of aggressive monitoring and treatment to improved outcomes in severe traumatic brain injury

OBJECT Despite being common practice for decades and being recommended by national guidelines, aggressive monitoring and treatment of patients with severe traumatic brain injury (TBI) have not been supported by convincing evidence. METHODS The authors reviewed trials and case series reported after 1970 in which patients were treated for severe closed TBI, and mortality rates and favorable outcomes at 6 months after injury were analyzed. The patient groups were divided into those with and without intracranial pressure (ICP) monitoring and intensive therapy, and the authors performed a meta-analysis to assess the effects of treatment intensity on outcome. RESULTS Although the mortality rate fell during the years reviewed, it was consistently approximately 12% lower among patients in the intense treatment group (p < 0.001). Favorable outcomes did not change significantly over time, and were 6% higher among the aggressively treated patients (p = 0.0105). CONCLUSIONS Aggressive ICP monitoring and treatment of patients with severe TBI is associated with a statistically significant improvement in outcome. This improvement occurs independently of temporal effects.

Have we made progress in preventing shunt failure? A critical analysis.

OBJECT The goal of this study was to determine whether failure rates of hydrocephalus shunts have fallen over the years as a result of experience or technical improvements. METHODS A structured search was performed of the English language literature for case series reporting failure rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to analyze failure rates statistically for temporal trends. Separate models were used for children (< 17 years old) and adults. RESULTS In children, the shunt failure rate was 31.3% for the 1st year and 4.5% per year thereafter. There were no significant changes in either rate over time. Although 1st-year failure rates in adults have fallen slightly over time, late failure rates have risen. CONCLUSIONS Progress in preventing shunt failures has not been made over the last several decades. Any improvements made in shunt materials or insertion techniques have been overshadowed by biological and other factors.

Is routine computed tomography scanning too expensive for mild head injury

OBJECTIVE To compare relative costs of treating mildly head-injured patients by routine admission or by using skull radiographs or cranial computed tomography (CT) scanning to screen patients for admission. DESIGN Retrospective record review, hypothetical costs based on actual patient course and requirements. SETTING Southern New Jersey Regional Trauma Center at Cooper Hospital/University Medical Center. PARTICIPANTS 658 consecutive mildly head-injured patients admitted from 1986 to 1988. All were given cranial CT scans. MEASUREMENTS Records were reviewed retrospectively and hypothetical costs were calculated based on actual length of hospitalization, surgical intervention, etc. These costs were compared for different treatment protocols. MAIN RESULTS The average cost if every patient had been admitted for observation given skull radiographs, with CT scans done on those exhibiting skull fracture or later deterioration, was