Head-injured patients who talk and deteriorate into coma. Analysis of 211 cases studied with computerized tomography

‘Talk and Die’ patients presenting to a major trauma centre over a 10 year period: A critical review

'Talk and die patients' describes a small number of patients who present with a mild head injury (Glasgow Coma Scale [GCS] 13-15) and then subsequently deteriorate and die from intracranial causes. We analysed the medical records of all those adult patients whose primary diagnosis as the cause of death was head injury, as determined by the coroner, who were admitted to a major Australian trauma centre between January 1994 and December 2003 (a 10-year period). The clinical profile of those patients who fulfilled the criteria of 'talk and die' were documented, including age, mode of injury, initial GCS, lucid interval, CT scan reports, operation performed, post mortem findings and intracranial cause of death. Factors considered potentially contributory to the patients' deterioration, such as delays in CT scanning or patient transfer, coagulopathy or hypoxic episodes were also noted. The incidence of 'talk and die' patients was 2.6% (15 out of 569) overall and the annual incidence did not significantly alter over the 10-year period of the study. The small number of patients precludes inferences regarding causal relationships, although potentially preventable factors, which could have been contributory to patient deterioration, were identified.

Pediatric minor traumatic brain injury

The literature surrounding minor traumatic brain injury is complex, methodologically challenging, and controversial. Although we lack a consistent standardized definition, the annual rate is likely in excess of 200 per 100,000 children. The proportion of children with minor traumatic brain injury who will require neurosurgery is certainly <1%. Several studies are underway that have the potential to significantly advance our understanding of the specific risk factors for intracranial injury and more specifically neurosurgical injury. The mortality within children is very low, with estimates of 0% to 0.25%. Virtually all studies of the prognosis of minor brain injury in children have reported no long-term behavioral or cognitive sequelae as a specific result of the brain injury. Symptoms fall in 4 domains: somatic, cognitive, sleep/fatigue, and affective. Limited pediatric studies are available to assist clinicians in the prognosis or in optimizing recovery. Until further studies are available, a conservative approach is recommended. Children with suspected concussions should be removed from activity and observed. Children with symptomatic concussions must be limited to no physical activity. Adolescents and families need to self-monitor symptoms and limit environments or circumstances that exacerbate any symptoms. When symptoms resolve, a gradual progressive return to play is currently recommended. The recurrence risk for subsequent concussions is elevated, but there is limited documentation of the effectiveness of preventative efforts. Much remains to be learned.

The use of recombinant factor VIIa (NovoSeven) for treatment of active or impending bleeding in brain injury: broadening the indications

We report three patients with severe traumatic brain injury, both open and closed, who were treated with recombinant activated factor VII. This treatment was given in a desperate, last-ditch effort to save the life of patient 1, as a preventive or early treatment of a developing hematoma in patient 2, and as treatment of a threatening hematoma in patient 3. One of the three patients survived. During the past few years we have broadened the indications for recombinant activated factor VII and started using it as a preventive measure rather than as a "last line of defense." However, the potential complications of disseminated intravascular coagulation and thrombotic events, as well as the cost-effectiveness in view of the available evidence-based medicine, should be considered.

Clinical Features of Head Injury Patients Presenting With a Glasgow Coma Scale Score of 15 and Who Require Neurosurgical Intervention

STUDY OBJECTIVE

Emergency physicians are concerned about minor head injury patients who present with a Glasgow Coma Scale (GCS) score of 15 yet require neurosurgical intervention. Our objectives are to determine the accuracy of the Canadian CT Head Rule (CCHR) in this important subset, the prevalence of patients requiring urgent intervention, and their clinical course and possible warning signs.

METHODS

We conducted a secondary data analysis of the CCHR study cohorts from 10 hospital emergency departments (EDs). We included head trauma patients with witnessed loss of consciousness, disorientation, or definite amnesia and who presented with an initial GCS score of 15. Records were reviewed and specific variables added to the database. The primary outcome was need for urgent neurosurgical intervention.

RESULTS

Among the 4,551 study patients, only 26 (0.6%; 95% confidence interval [CI] 0 to 1.0%) required neurosurgical intervention, and the CCHR identified all 26 cases with 100% sensitivity. Eleven patients required "urgent" craniotomy within 7 days, and of those, 2 patients deteriorated precipitously. These 11 (0.2%; 95% CI 0.1% to 0.3%) cases had additional signs: GCS score decrease within 6 hours (82%), GCS score decrease within 3 hours (73%), confusion (64%), any vomiting (36%), focal temporal blow (36%), restlessness (36%), and severe headache (45%).

CONCLUSION

For patients with minor head injury and GCS score of 15, urgent neurosurgical intervention and precipitous deterioration are rare. The CCHR accurately identified all patients requiring neurosurgical intervention. Warning signs that may portend need for urgent intervention include any vomiting, restlessness, any GCS score decrease, severe headache, confusion, and focal temporal blow.

Clinical characteristics of postoperative contralateral intracranial hematoma after traumatic brain injury

OBJECTIVES

To investigate the clinical characteristics of contralateral intracranial hematoma (ICH) after traumatic brain injury.

METHODS

The subjects included 149 patients with traumatic ICH treated by hematoma evacuation. The patients were retrospectively divided into a bilateral ICH (B-ICH) group and unilateral ICH (U-ICH) group after craniotomy using brain CT scans for comparison of the following parameters: complicated expanded brain bulk from the cranial window, hypotension during craniotomy, and outcome.

RESULTS

Post-craniotomy brain CT scans revealed U-ICH in 106 patients and B-ICH in 43 patients. Average Glasgow Coma Scale on arrival did not differ between the groups, but a higher proportion of patients in the B-ICH group deteriorated after admission (p = 0.02). The B-ICH patients also exhibited a significantly higher rate of expanded brain bulk from the cranial window (p < 0.05). No significant difference was observed between the groups with hypotension during craniotomy. The B-ICH group exhibited a lower rate of favorable outcome (p < 0.05) and higher mortality (p < 0.05).

CONCLUSION

The B-ICH patients had a worse outcome than the U-ICH patients. Contralateral ICH was difficult to forecast based on pre- and intraoperative clinical conditions. Subdural hematoma or contusional ICH was frequently observed as a contralateral ICH.

Changes in Cerebral Blood Flow from the Acute to the Chronic Phase of Severe Head Injury

We studied cerebral blood flow (CBF) in the transition from the acute to the chronic phase of severe head injury in order to determine patterns of change in relation to neurological outcome. We measured CBF with stable xenon-enhanced computed tomography (Xe-CT) in 20 consecutive patients at 1, 2, 3, 4, and 6 weeks after severe head injury, and analyzed the relation between the pattern of change in CBF and neurological outcome at 6 months after injury. CBF values were significantly lower in the brain-injured patients than in 14 healthy volunteers, except at 3 weeks after injury, when CBF increased in the patients to a value that did not differ significantly from that in the normal volunteers. We therefore focused on the change in CBF at 3 weeks after injury. We separated the 20 brain-injured patients into two subgroups, of which the first (subgroup A) consisted of nine patients whose CBF had returned to normal by week 3 post-injury, while the second (subgroup B) consisted of 11 patients whose CBF was subnormal at week 3 post-injury. CBF was significantly higher in subgroup A than in subgroup B at 2 weeks post-injury (p < 0.05). CBF in subgroup B remained significantly lower than that in subgroup A throughout the study period. At 6 months post-injury, subgroup A had a significantly better neurological outcome than did subgroup B (p < 0.05). We conclude that patients whose CBF returns to normal at 2-3 weeks following severe traumatic brain injury after being abnormally low in the acute phase of injury can be expected to achieve a good neurological outcome.

Motor vehicle crash brain injury in infants and toddlers: a suitable model for inflicted head injury?

OBJECTIVE

Children involved in motor vehicle crash (MVC) events might experience angular accelerations similar to those experienced by children with inflicted traumatic brain injury (iTBI). This is a pilot study to determine whether the progression of signs and symptoms and radiographic findings of MVC brain injury (mvcTBI) in children of the age at greatest risk of iTBI could be evaluated with retrospective data. The ultimate goal was to examine the association of subdural hematoma (SDH) with initial loss of consciousness (LOC) and outcome.

METHODS

Retrospective review of records was conducted of 51 patients involved in a MVC, between birth and 36 months, admitted to Harborview Medical Center between January 1996 and December 2001. Radiographs were reviewed. Simple descriptive statistics and Fisher's exact test were used.

RESULTS

Ambulance reports were available for 57% of the patients, while Glasgow Coma Scale (GCS) scores (from any source) were only available for 76% of patients. Thirty-nine percent of patients sustained skull fractures, 8% long bone fractures, 20% thoracic injuries, and 8% intra-abdominal injuries. Twenty-four percent of the patients had SDHs; half of these experienced LOC. SDH patients without initial LOC had computed tomography findings and clinical courses indicative of focal impact injury, not angular acceleration.

CONCLUSIONS

Initial LOC and subsequent evolution of GCS scores are inconsistently documented in retrospective records. Seven of the 12 patients with SDHs had simple contact injuries, while 5 exhibited diffuse brain injury. Initial LOC was associated with diffuse brain injury and poor outcome. Due to the high rate of simple contact injury, mvcTBI may be a difficult model for iTBI.

Acute Subdural Hematoma: New Model Delineation and Effects of Coagulation Inhibitors

OBJECTIVE

To develop a highly reproducible rat model and behavioral tests for acute subdural hematoma (ASDH) and to investigate the role of intravascular coagulation and thrombin in the pathogenesis of brain injury in this model.

METHODS

A new method was implemented to inject 200 microl of autologous blood subdurally in rats. Immunohistochemistry was used to investigate intravascular fibrin deposition and thrombin levels in the cortex underlying the ASDH. Effectiveness of systemic heparin, argatroban, or ginkgolide B treatment was determined by histological lesion volume, number of occluded microvessels, and neurological deficits. Neurological deficits were monitored for 7 days after ASDH by use of forelimb placing, forelimb use asymmetry, and corner turn tests.

RESULTS

Consistent brain damage and sensorimotor deficits were observed in all animals with ASDH. Histological analysis demonstrated occluded microvessels and enlarged perivascular spaces in the underlying cortex starting 1 hour after hematoma induction. Fibrin and thrombin immunoreactivity were increased in the lesioned cortical parenchyma at 4 and 24 hours. However, no intravascular fibrin deposition was detected. Heparin induced hemorrhagic transformation in the cortical lesion and did not attenuate microvessel occlusion. Argatroban and ginkgolide B did not induce hemorrhage but failed to improve microvessel occlusion, lesion volume, and neurological deficits.

CONCLUSION

Intravascular coagulation and thrombin are not the major mediators of brain damage after ASDH. The model and behavioral tests presented in this study can be used to investigate other putative mechanisms of injury and to test future therapeutic interventions in ASDH.

Transcranial Doppler to detect on admission patients at risk for neurological deterioration following mild and moderate brain trauma

OBJECTIVE

To investigate the contribution of transcranial Doppler measurements obtained in the emergency room for detecting patients with secondary neurological deterioration after mild or moderate brain trauma.

DESIGN AND SETTING

Prospective cohort study in the emergency room in a university teaching hospital.

PATIENTS

Seventy-eight adult patients admitted to the emergency room after a traumatic brain injury (TBI), including 42 patients with Glasgow Coma Score 14-15 and 36 with 9-13.

MEASUREMENTS AND RESULTS

All patients had transcranial Doppler measurements on both middle cerebral arteries and computed tomography on admission. Neurological outcome was assessed 7 days after trauma. Of the patients included 7 and 10 had secondary neurological deterioration after mild and moderate TBI, respectively. On admission these groups of patients had significantly more injuries on computed tomography using the Trauma Coma Data Bank classification and higher pulsatility index using transcranial Doppler than the patients having no subsequent neurological worsening.

CONCLUSIONS

Increased pulsatility index after mild or moderate TBI is a reason for concern about the possibility of further neurological deterioration. Computed tomography and Doppler measurements could be combined to detect on admission patients at risk for secondary neurological deterioration in order to improve their initial disposition.

Mild head injury: reliability of early computed tomographic findings in triage for admission

OBJECTIVE

To search the literature for case reports on adverse outcomes in patients with mild head injury where acute computed tomography (CT) findings had been normal.

METHODS

Mild head injury was defined as head trauma involving amnesia or loss of consciousness, but where neurological findings are normal on arrival at hospital (GCS 15). The scientific literature was systematically searched for case reports where an early CT was normal and the patient deteriorated within two days. In these cases, early discharge despite a normal CT head scan would have been hazardous.

RESULTS

Two prospective studies were found that investigated the safety of early CT in 3300 patients with mild head injury, as were 39 reports on adverse outcomes describing 821 patients. In addition, 52 studies containing over 62 000 patients with mild head injury were reviewed. In total, only three cases were deemed to have experienced an early adverse outcome despite a normal CT and GCS 15 on initial presentation. In another eight cases with incomplete descriptions, the interpretation was doubtful. Many reports of complications were not relevant to our question and excluded. These reports included cases with more severe head injury/not GCS 15 at presentation, complications that occurred after more than two days, or initial CT findings that were not fully normal.

CONCLUSION

Very few cases were found where an early adverse event occurred after normal acute CT in patients with mild head injury. The strongest scientific evidence available at this time shows that a CT strategy is a safe way to triage patients for admission.

Thrombocytopenia Predicts Progressive Hemorrhage after Head Trauma

Patients with traumatic brain injury (TBI) often show progression of hemorrhagic injuries (PHI) after admission to the hospital. This progression is correlated with poor outcome. In this study, we have investigated if thrombocytopenia was a risk factor for PHI. The study was performed on patients admitted to the hospital with severe TBI during year 2000. In total, 50 patients were admitted with severe TBI. Twenty-seven out of these had complete platelet counts at admission and 24 hours thereafter and were included for further study. We found thrombocytopenia at admission to be a risk factor for PHI (p=0.008). We also found that the platelet count decreased more significantly during the first 24 h after injury in patients with PHI compared to patients without PHI (p=0.009). A trend towards longer periods of mechanical ventilation in patients with PHI compared to patients without PHI was identified. These findings support a causal relationship between thrombocytopenia and PHI. The findings provide a rationale for future studies of hemostatic agents in the treatment of TBI in order to minimise complications caused by PHI.

Coagulopathy as a parameter to predict the outcome in head injury patients – analysis of 61 cases

The correlation of coagulopathy and pupillary light reflex, the degree of midline shift in brain computer tomography and Glasgow outcome scale (GOS) after head injury were prospectively evaluated. From September 2002 to March 2003, 61 patients (45 males and 16 females; mean age: 41.9 years) after head injury were enrolled in the study. A modified coagulopathy score (CS) defined by prothrombin time, partial thromboplastin time, platelet count, D-dimer and fibrinogen was calculated for each patient within 24 h after injury. The CS was 2.3+/-2.7 (mean+/-SD). The incidence of abnormal coagulation following head injury in non-survival cases was 100% and in survival cases 66%. The mortality rate was significantly increased to 75% in CS above 4 and 100% if CS was 6 or greater. The increase of D-dimer concentration appears to be common yet abnormal platelet counts are relatively uncommon among head trauma patients. Within 4 h after head injury, there is an initial hypercoagulable stage followed by hypocoagulable stage 6 h after head injury. Our results showed pupillary light reflex has the most significant correlation to GOS (rho = 0.727, p < 0.0001). It also reveals that coagulopathy score > or 4 (positive predictive value 90%) may have higher degree of accuracy to predict mortality comparing to both pupils being fixed or brain CT midline shift > or = 15 mm. We conclude that: (1) Coagulation state in head injury patients within 24 h after injury is of value in determining the outcome. (2) Coagulopathy score > or = 4 is a good predictor to evaluate mortality rate of head injury patients.

Neurophysiological monitoring, magnetic resonance imaging, and histological assays confirm the beneficial effects of moderate hypothermia after epidural focal mass lesion development in rodents

OBJECTIVE

To assess the effects of moderate intraischemic hypothermia on neurophysiological parameters in an epidural balloon compression model in rats and to correlate the results with magnetic resonance imaging and histological findings.

METHODS

Neurophysiological monitoring included laser Doppler flow, tissue partial oxygen pressure, and intracranial pressure measurements and electroencephalographic assessments during balloon expansion, sustained inflation, and reperfusion. Moderate intraischemic cooling of animals was extended throughout the reperfusion period, and results were compared with those for normothermic animals. Moreover, histological morphometric and magnetic resonance imaging volumetric analyses of the lesions were performed.

RESULTS

Laser Doppler flow decreased slightly during ischemia (P < 0.05) in animals treated with hypothermia, and flow values demonstrated complete reperfusion, compared with incomplete flow restoration in untreated animals (P < 0.05). During ischemia, the tissue partial oxygen pressure was less than 4.3 mm Hg in both groups. After reperfusion, values returned to the normal range in both groups, but the tissue partial oxygen pressure in hypothermic animals was significantly higher (P = 0.042) and demonstrated 19% higher values, compared with normothermic animals, before rewarming. Moderate hypothermia attenuated a secondary increase in intracranial pressure (P < 0.05), and electroencephalographic findings indicated a trend toward faster recovery (P > 0.05) after reperfusion. Lesion size was reduced by 35% in magnetic resonance imaging volumetric evaluations and by 24.5% in histological morphometric analyses.

CONCLUSION

Intraischemic hypothermia improves cerebral microcirculation, attenuates a secondary increase in intracranial pressure, facilitates electroencephalographic recovery, and reduces the lesion size.

Elevated Serum S-100B Protein as a Predictor of Failure to Short-Term Return to Work or Activities after Mild Head Injury

Protein S-100B is an established serum marker of primary and secondary brain damage and stroke. A group of patients after mild head injury (MHI) develop post-concussion symptoms that interfere with the ability in the short-term to return to work or undertake certain activities. The aim of this study was to examine the correlation of serum S-100B with short-term outcome after MHI. We studied 100 subjects who were referred to the Emergency Department (ED) after a MHI. All subjects had a GCS of 15 either with or without loss of consciousness (LOC) and/or post-traumatic amnesia (PTA). Serum S-100B was collected within 3 h from the injury and a value of > or = 0.15 microg/L was considered as abnormal. Subjects with other injuries, including scalp or cervical spine, were excluded, as well as those with alcohol/narcotic drug consumption or history of serious physical/mental illness. An independent observer measured the return to work/activities within one week. Thirty-two (32%) subjects had elevated S-100B. The failure to return to work/activities was significantly correlated with elevated S-100B: subjects with increased S-100B had a failure rate of 37.5% versus 4.9% of those with normal values (p = 0.0001). In MHI, the elevated S-100B seemed to correlate with an unfavorable short-term outcome. This might be useful in (1) selecting patients who need closer observation, hospitalization, and further investigations (such as CT scan or MRI), and (2) the prognosis of genuine post-concussion symptoms, that interfere with return to work or activities, versus other causes such as premorbid personality, labyrinthine dysfunction, whiplash syndrome, postinjury stress, occupational injury, litigation, and malingering.

The use of bispectral index to monitor unconscious children

The use of the Glasgow Coma Scale may be limited by the experience of physicians, errors resulting from subjectivity, the inability of patients to respond, and discontinuity. This study demonstrates that the Bispectral Index scores correlate well with scores from the Glasgow Coma Scale and that Bispectral Index scores can provide real-time, objective, and continuous monitoring of the consciousness level of critically ill children. Sixteen patients with consciousness disturbance, who were admitted to a pediatric intensive care unit of a tertiary university-affiliated children's hospital, were enrolled in this study. The patients received 34 Glasgow Coma Scale assessments and Bispectral Index scores. The age of patients ranged from 10 to 192 months (mean +/- S.E. = 68.4 +/- 12.3 months). Glasgow Coma Scale ranged from 3 to 11 (mean +/- S.E. = 6.3 +/- 0.4), and Bispectral Index score ranged from 0 to 100 (mean +/- S.E. = 55.4 +/- 5.6). A positive correlation was found to exist between Glasgow Coma Scale and Bispectral Index score (r = 0.76, P < 0.001). In conclusion, the Bispectral Index score correlates well with the Glasgow Coma Scale in critically ill children who score between 3 and 11 on the Glasgow Coma Scale.

Does an isolated history of loss of consciousness or amnesia predict brain injuries in children after blunt head trauma?

BACKGROUND

A history of loss of consciousness (LOC) is frequently used as an indication for cranial computed tomography (CT) in the emergency department (ED) evaluation of children with blunt head trauma.

OBJECTIVE

We sought to determine whether an isolated LOC and/or amnesia is predictive of traumatic brain injury (TBI) in children with blunt head trauma.

METHODS

We prospectively enrolled children <18 years old presenting to a level I trauma center ED between July 1998 and September 2001 with blunt head trauma. We evaluated the association of LOC and/or amnesia with 1) TBI identified on CT and 2) TBI requiring acute intervention. We defined the latter by a neurosurgical procedure, antiepileptic medication for >1 week, persistent neurologic deficits, or hospitalization for > or =2 nights. We then investigated the association of LOC and/or amnesia with TBI in those patients without other symptoms or signs of TBI ("isolated" LOC and/or amnesia).

RESULTS

Of eligible children, 2043 (77%) were enrolled, 1271 (62%) of whom underwent CT; 1159 (91%) of these 1271 had their LOC and/or amnesia status known. A total of 801 (39%) of the 2043 enrolled children had a documented history of LOC and/or amnesia. Of the 745 with documented LOC and/or amnesia who underwent CT, 70 (9.4%; 95% confidence interval [CI]: 7.4%, 11.7%) had TBI identified on CT versus 11 of 414 (2.7%; 95% CI: 1.3%, 4.7%) without LOC and/or amnesia (difference: 6.7%; 95% CI: 4.1%, 9.3%). Of the 801 children known to have had LOC and/or amnesia (regardless of whether they underwent CT), 77 (9.6%; 95% CI: 7.7%, 11.9%) had TBI requiring acute intervention versus 11 of 1115 (1%; 95% CI: 0.5%, 1.8%) of those without LOC and/or amnesia (difference: 8.6%; 95% CI: 6.5%, 10.7%). For those with an isolated LOC and/or amnesia without other signs or symptoms of TBI, however, 0 of 142 (95% CI: 0%, 2.1%) had TBI identified on CT, and 0 of 164 (95% CI: 0%,1.8%) had TBI requiring acute intervention.

CONCLUSIONS

Isolated LOC and/or amnesia, defined by the absence of other clinical findings suggestive of TBI, are not predictive of either TBI on CT or TBI requiring acute intervention. Elimination of an isolated LOC and/or amnesia as an indication for CT may decrease unnecessary CT use in those patients without an appreciable risk of TBI.

Characteristics of parietal-parasagittal hemorrhage after mild or moderate traumatic brain injury

The aim of this study is to clarify the clinical characteristics of parietal-parasagittal traumatic intracranial hemorrhage (TICH) after mild or moderate traumatic brain injury (TBI). METHODS; Subjects were 105 patients with mild or moderate TBI. The patients with parietal-parasagittal TICH were clinically analyzed based on the initial brain CT findings, hematoma sites and the clinical course as compared to those with TICH at other sites.

RESULTS

Hematoma was located in the frontal or temporal lobes in 89.5% of the subjects and the parietal-parasagittal in 10.5%. Ten of the 11 patients suffering parietal-parasagittal TICH had skull fractures (7 depressed and 3 linear) but no depressed fracture observed in patients with frontal or temporal lobe hemorrhage. Neurological deterioration leading to a comatose state more frequently occurred in 63.6% of patients with parietal-parasagittal TICH than in those with frontal or temporal lobe hemorrhage (19.1%, p < 0.01). The incidence of hematoma growth was significantly higher in patients with parietal-parasagittal TICH (63.6%) than in those with frontal or temporal lobe hemorrhage (31.9%, p < 0.05).

DISCUSSION

The incidence of parietal-parasagittal TICH is low, but the risk of neurological deterioration due to hematoma enlargement is significantly high. Parietal-parasagittal TICH may differ clinically from frontal-temporal TICH.

Moderate hypothermia improves neurobehavioral deficits after an epidural focal mass lesion in rodents

The objective of this study was to evaluate the effects of a moderate, intraischemic hypothermia on the behavorial deficits up to 4 weeks after induction of a focal mass lesion. A focal epidural mass lesion was induced by an epidural balloon. The severity of the trauma was defined by the balloon volume and flattening of electroencephalography. Hypothermia (32 degrees C) was induced as soon as maximum balloon infIation was reached. Ischemia was extended over 30 min. After reperfusion, normothermic (n = 24) and hypothermic animals (n = 25) were monitored for 3 h followed by a rewarming of the cooled animals. Results were compared to sham-operated animals (n = 10). Behavioral deficits were assessed by postural reflex (PR), open field (OF), beam balance (BB), beam walking (BW), and water maze tests (WMT). MRI follow-up and histology was evaluated. Sham-operated rats showed normal test results. Rats with normothermia showed worsening of test performance (PR, p < 0.05; OF, p < 0.05; BB, p < 0.05; BW, p < 0.05; WMT, p < 0.05) compared to controls over the whole observation period. A significantly better behavioral outcome was observed in animals treated with hypothermia which showed no differences from controls 3-4 days after injury (PR, OF, BB, BW, WMT, p > 0.05). Lesion induced mortality was reduced in cooled animals but overall mortality rates were not influenced by this therapeutic measure. Neuronal cell loss in the CA1-CA4 region (p < 0.05) was reduced and the lesion size smaller (21%/p > 0.05) in hypothermic animals. Magnetic resonance imaging revealed that the lesion was more pronounced in the cortical grey matter after normothermia, whereas hypothermic animals showed more subcortical brain lacerations. In conclusion, intraischemic hypothermia significantly improved the behavioral outcome, and decreased lesion-induced mortality and the size of the lesion after an epidural focal mass lesion.

Patients with a head injury who "talk and die" in the 1990s

BACKGROUND

Patients who "talk and die" after head injury may represent a group who suffer delayed and therefore potentially preventable complications after injury. We have compared the clinical and pathologic features of patients who talk and die with those who "talk and live" after head injury.

METHODS

Data collected prospectively by the Scottish Trauma Audit Group were used to identify patients with a head injury and classify them according to verbal response at admission to hospital. All "talking" patients in the catchment area of a regional neurosurgical center were selected and those who died were compared with those who survived.

RESULTS

Seven hundred eighty-nine talking patients were identified. Seven hundred twenty-seven patients survived and 62 died. Patients who talked and died were older, had more severe extracranial injuries, had lower consciousness levels, and reached theater more quickly than those who talked and lived. Thirty-one of the patients that died had extra-axial hematomas.

CONCLUSION

Even with increased availability of computed tomographic scanning, some patients still talk and die after head injury.

A new reproducible model of an epidural mass lesion in rodents. Part I: Characterization by neurophysiological monitoring, magnetic resonance imaging, and histopathological analysis

OBJECT

The goal of this study was to characterize a new model of an epidural mass lesion in rodents by means of neurophysiological monitoring, magnetic resonance imaging, and histopathological analysis.

METHODS

Changes in intracranial pressure (ICP), cerebral perfusion pressure (CPP), and laser Doppler flowmetry (LDF) values, intraparenchymal tissue partial oxygen pressure (PtiO2), and electroencephalography (EEG) activity were evaluated in the rat during controlled, epidural expansion of a latex balloon up to a maximum ICP of 60 mm Hg. The initial balloon inflation was followed by periods of sustained inflation (30 +/- 1 minute) and reperfusion (180 +/- 5 minutes). Histopathological analysis and magnetic resonance (MR) imaging were performed to characterize the lesion. The time to maximum balloon expansion and the average balloon volume were highly reproducible. Alterations in EEG activity during inflation first appeared when the CPP decreased to 57 mm Hg, the LDF value to 66% of baseline values. and the PtiO2 to 12 mm Hg. During maximum compression, the CPP was reduced to 34 mm Hg, the LDF value to 40% of baseline, and the PtiO2 to 4 to 5 mm Hg. The EEG tracing was isoelectric during prolonged inflation and the values of LDF and PtiO2 decreased due to accompanying hypotonia. After reperfusion, the CPP was significantly decreased (p < 0.05) due to the elevation of ICP. Both the LDF value and EEG activity displayed incomplete restoration, whereas the value of PtiO2 returned to normal. Histological analysis and MR imaging revealed brain swelling with a midline shift and a combined cortical-subcortical ischemic lesion beyond the site of balloon compression.

CONCLUSIONS

This novel model of an epidural mass lesion in rodents closely resembles the process observed in humans. Evaluation of pathophysiological and morphological changes was feasible by using neurophysiological monitoring and MR imaging.

A reproducible model of an epidural mass lesion in rodents. Part II: Characterization by in vivo magnetic resonance imaging

OBJECT

The goal of this study was to characterize a novel epidural space-occupying lesion caused by balloon expansion in rodents by using sequential in vivo magnetic resonance (MR) imaging.

METHODS

Ten Sprague-Dawley rats were intraperitoneally sedated. A trephination was performed over the left parietal cortex to attach a balloon-expansion device, which was secured with dental cement. Measurements were performed using a 1.5-tesla MR imaging device to obtain sequential T2-weighted and diffusion-weighted (DW) sequences in the coronal plane. A three-dimensional, constructed interference in steady state sequence was used for calculation of the balloon volume. The animal's temperature, heartbeat, and the arterial percentage of oxygen saturation were monitored continuously. After a baseline examination had been performed, the balloon was inflated for a 30-minute period until it reached a maximum volume of 0.3 ml; this procedure was followed by a period of sustained inflation lasting 30 minutes, balloon deflation, and a period of reperfusion lasting 3 hours. After perfusion fixation of the animals, morphometric analysis of the lesion size and examination of the percentage of viable neurons in the hippocampus were performed. Magnetic resonance imaging allowed for the precise visualization of the extension and location of the epidural mass lesion, narrowing of the basal cisterns, and development of a midline shift. A white-matter focus of hyperintensity, consistent with brain edema, developed, predominantly in the contralateral temporal lobe. During sustained inflation the volume of the balloon did not change and comprised 5 to 7% of total intracranial volume. During the same period the white-matter edema progressed further but no increased signal was revealed on DW images. After balloon deflation the brain reexpanded to the calvaria and imaging signs of raised intracranial pressure subsided. A cortical area of hyperintensity on T2-weighted images developed in the parietal lobe in the region of the former balloon compression. This area appeared bright on DW images, a finding that corresponded to an early cytotoxic edema. After deflation white-matter vasogenic edema in the temporal lobes regressed within 3 hours after reperfusion. The cortical edema in the parietal lobe and the ipsilateral basal ganglia became sharply demarcated. The histopathological results (that is, the extent of tissue damage) corresponded with findings of the authors' companion investigation, which appears in this issue.

CONCLUSIONS

Magnetic resonance imaging allows for a precise and sequential in vivo monitoring of a space-occupying epidural mass lesion and visualizes the time course of vasogenic and cytotoxic brain edema. This rodent model of an epidural mass lesion proved to be reproducible.

Progressive hemorrhage after head trauma: predictors and consequences of the evolving injury

OBJECT

Progressive intracranial hemorrhage after head injury is often observed on serial computerized tomography (CT) scans but its significance is uncertain. In this study, patients in whom two CT scans were obtained within 24 hours of injury were analyzed to determine the incidence, risk factors, and clinical significance of progressive hemorrhagic injury (PHI).

METHODS

The diagnosis of PHI was determined by comparing the first and second CT scans and was categorized as epidural hematoma (EDH), subdural hematoma (SDH), intraparenchymal contusion or hematoma (IPCH), or subarachnoid hemorrhage (SAH). Potential risk factors, the daily mean intracranial pressure (ICP), and cerebral perfusion pressure were analyzed. In a cohort of 142 patients (mean age 34 +/- 14 years; median Glasgow Coma Scale score of 8, range 3-15; male/female ratio 4.3: 1), the mean time from injury to first CT scan was 2 +/- 1.6 hours and between first and second CT scans was 6.9 +/- 3.6 hours. A PHI was found in 42.3% of patients overall and in 48.6% of patients who underwent scanning within 2 hours of injury. Of the 60 patients with PHI, 87% underwent their first CT scan within 2 hours of injury and in only one with PHI was the first CT scan obtained more than 6 hours postinjury. The likelihood of PHI for a given lesion was 51% for IPCH, 22% for EDH, 17% for SAH, and 11% for SDH. Of the 46 patients who underwent craniotomy for hematoma evacuation, 24% did so after the second CT scan because of findings of PHI. Logistic regression was used to identify male sex (p = 0.01), older age (p = 0.01), time from injury to first CT scan (p = 0.02), and initial partial thromboplastin time (PTT) (p = 0.02) as the best predictors of PHI. The percentage of patients with mean daily ICP greater than 20 mm Hg was higher in those with PHI compared with those without PHI. The 6-month postinjury outcome was similar in the two patient groups.

CONCLUSIONS

Early progressive hemorrhage occurs in almost 50% of head-injured patients who undergo CT scanning within 2 hours of injury, it occurs most frequently in cerebral contusions, and it is associated with ICP elevations. Male sex, older age, time from injury to first CT scan, and PTT appear to be key determinants of PHI. Early repeated CT scanning is indicated in patients with nonsurgically treated hemorrhage revealed on the first CT scan.

The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation)

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. "Minor" head injury (sometimes known as "mild") is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

Does second impact syndrome exist?

Second impact syndrome (SIS) is a widely feared complication of traumatic brain injury. Although postulated to occur after repeated concussion, the evidence for such a premise is not compelling. This paper reviews the published evidence for and against the existence of this controversial entity. Rather than SIS being a complication of recurrent concussion, it is far more likely that the clinical condition represents "diffuse cerebral swelling," a well-recognized complication of traumatic brain injury. This condition is more common in children and adolescents, which reflects the known demographics of so-called "second impact syndrome." We propose that clinicians abandon the misleading term second impact syndrome and refer to the syndrome as diffuse cerebral swelling.

Discrepancy of clinical symptoms and prognosis of a patient--forensic significance of "talk and die" head injury

Deaths of patients who had talked after sustaining a head injury and were then assumed clinically to be recovering from the head trauma raise medicolegal questions about the precise causes of deaths. A forensic autopsy on a 77-year-old man who had been talking after a road traffic accident and died on the sixth day showed slight subdural hematoma, bifrontal cerebral contusions and diffuse axonal injury. No natural diseases or delayed complications of injury were found. The cause of death was certified as head injury due to a traffic accident. This is a case of "talk and die" head injury. Forensic autopsy is important in patients with "talk and die" to clarify the causal relation to the head trauma in relation to any further forensic dispute.

Midline shift after severe head injury: pathophysiologic implications

OBJECTIVE

To investigate the mechanism of the adverse effect of midline shift after severe traumatic brain injury.

METHODS

This study compared averaged cerebral metabolic parameters of patients with midline shift > 5 mm (S) on initial computerized tomography scan to those of patients with shift < or = 5 mm (NS). The effect of an acute subdural hematoma (SDH) was determined by separating patients into those with and those without SDH and then re-examining the effect of shift in these subgroups.

RESULTS

Four hundred fifty-four patients were studied. Cerebral metabolic rate of oxygen (CMRO2, in mL/100 g per min) was always lower with shift: 1.74 for SDH-S versus 2.21 for SDH-NS (p < 0.001), and 1.80 for non-SDH-S versus 2.24 for non-SDH-NS (p < 0.001). No other major effects of shift were seen in SDH patients. Among non-SDH patients, shift was associated with higher intracranial pressure (ICP): 23.1 mm Hg versus 16.3 mm Hg (p < 0.001). Other differences between shift and nonshift patients in the non-SDH group were due at least in part to interventions to treat the elevated ICP.

CONCLUSION

Midline shift after severe traumatic brain injury is associated with reduced CMRo2, regardless of whether or not SDH is present. The deleterious effects of subdural blood may be related more to the mass effect of large SDHs than to the biochemical abnormalities caused by small amounts of blood in the subdural space.

Repeat computed tomographic scan within 24-48 hours of admission in children with moderate and severe head trauma

OBJECTIVE

To asses the yield and contribution of a routine predetermined repeat head computed tomographic (CT) scan within 24-36 hrs in pediatric patients with moderate to severe head trauma.

DESIGN

Records review.

SETTING

Five pediatric intensive care units.

PATIENTS

We reviewed the charts of 173 consecutive pediatric patients with moderate to severe head trauma (Glasgow Coma Scale score of < or = 11) that survived the first 24 hrs after being admitted to five Israeli trauma centers. Clinical data collected included status at admission, at the time between the first and second CT scans, and after the second scan. Head details of the first, second, and, if performed, third CT scan were collected. Treatment strategy during each period was recorded, including any change in treatment after each CT scan.

MEASUREMENTS AND MAIN RESULTS

A total of 47 (27%) of the second CT scans showed new lesions including six intracranial hemorrhages, 17 cases of worsening brain edema, and 18 newly diagnosed brain contusions. However, none of these findings necessitated surgical intervention or any change in therapy. Of the 67 patients who underwent a third CT scan, two cases required surgical intervention because of new findings in the third CT.

CONCLUSIONS

A second routine prescheduled head CT scan within 24-36 hrs after admission in pediatric patients with moderate to severe head trauma is unlikely to yield any change in therapy. Clinically and intracranial pressure-oriented CT scan may better select and diagnose patients who require changes in therapy, including surgery. Studies aimed to determine the ideal timing for the second are warranted.

Technical report: minor head injury in children

Minor head trauma affecting children is a common reason for medical consultation and evaluation. In order to provide evidence on which to base a clinical practice guideline for the American Academy of Pediatrics, we undertook a systematic review of the literature on minor head trauma in children.

METHODS

Medline and Health databases were searched for articles published between 1966 and 1993 on head trauma or head injury, limited to infants, children, and adolescents. Abstracts were reviewed for relevance to mild head trauma consistent with the index case defined by the AAP subcommittee. Relevant articles were identified, reviewed, and abstracted. Additional citations were identified by review of references and expert suggestions. Unpublished data were also identified through contact with authors highlighting child-specific information. Abstracted data were summarized in evidence tables. The process was repeated in 1998, updating the review for articles published between 1993 and 1997.

RESULTS

A total of 108 articles were abstracted from 1033 abstracts and articles identified through the various search strategies. Variation in definitions precluded any pooling of data from different studies. Prevalence of intracranial injury in children with mild head trauma varied from 0% to 7%. Children with no clinical risk characteristics are at lower risk than are children with such characteristics; the magnitude of increased risk was inconsistent across studies. Computed tomography scan is most sensitive and specific for detection of intracranial abnormalities; sensitivity and specificity of skull radiographs ranged from 21% to 100% and 53% to 97%, respectively. No high quality studies tested alternative strategies for management of such children. Outcome studies are inconclusive as to the impact of minor head trauma on long-term cognitive function.

CONCLUSIONS

The literature on mild head trauma does not provide a sufficient scientific basis for evidence-based recommendations about most of the key issues in clinical management. More consistent definitions and multisite assessments are needed to clarify this field.

[Indications for monitoring intracranial pressure]

A main indication for intracranial pressure monitoring is severe head trauma, where it acts as a diagnostic, prognostic and therapeutic guide. Others indications for intracranial pressure monitoring are patients with CSF circulation disturbances, whatever the cause, and various pathologies inducing intracranial hypertension, such as encephalopathies. Intracranial pressure monitoring must be associated with the measurement of mean arterial pressure, arterial and jugular venous oxygen saturation and blood flow velocity in major intracranial arteries with transcranial Doppler sonography.

Executive functioning as outcome in patients after traumatic brain injury

The present study was designed to determine how traumatic brain injury affect executive functioning, to know whether different treatments in the acute phase improve this functioning, and to check whether the severity of the neurocognitive impairment is detected by the Glasgow Outcome Scale (GOS). Ability for problem solving and executive functioning within 2 years after Traumatic Brain Injury (TBI) was examined in 35 conscious survivors. Two groups were formed. One group consisted of 13 patients who needed neurosurgery. The other group was made up of 22 patients without neurosurgical treatment. All were treated in the Neurosurgical Intensive Care Unit and in the Rehabilitation Service. The following variables were registered: Secondary Lesions, Glasgow Coma Scale (GCS), CT, subacute CT, and Glasgow Outcome Scale. Neuropsychological tests administered were Wisconsin Card Sorting Test (WCST) and the Tower of Hanoi/Sevilla. Comparing both groups' test performance (man Whitney U) we found that a severe traumatic brain injury, whatever the treatment applied in the acute phase, impairs the executive functioning of the patients; this impairment is related to acute pathophysiological events. The neurosurgical intervention does not improve the executive functioning. The Glasgow Outcome Scale does not detect more than 25% of the patients with severe impairment. It is suggested that the Tower of Hanoi/Sevilla could be a good tool to evaluate the executive functioning routinely in TBI patients as outcome. It also suggested that mild TBI patients must be referred for a complete neuropsychological examination.

Moderate head injury: a system of neurotrauma care

BACKGROUND

The aim of the present study was to determine those factors which contribute to a poor outcome and to propose a management plan that is complementary to trauma systems in common use.

METHODS

A prospective study of 110 consecutive patients with moderate head injury (post-resuscitation Glasgow Coma Scale (GCS) 9-13) was carried out.

RESULTS

A total of 75% of the patients sustained multisystem trauma, generally of minor or moderate grade according to the Abbreviated Injury Scale (AIS). However, the death rate increased with the severity of the injury as measured by the Injury Severity Score (ISS). The initial cranial computed tomography (CT) scan was abnormal in 61% and no patient with a normal scan developed a delayed intracranial haematoma or neurological worsening. Those patients who developed a delayed intracerebral haematoma had a worse outcome. Sixteen patients underwent craniotomy for haematoma. The intracranial pressure (ICP) was measured selectively in 20 patients and exceeded 20 mmHg in half, requiring treatment. Nine patients died, four as a result of head injury and all those had an intracranial haematoma. As a group, those who died were older and had a higher ISS.

CONCLUSIONS

A plan for care of patients with moderate head injury is proposed, complementary to the Early Management of Severe Trauma (EMST) protocol and the Neurosurgical Society of Australasia guidelines for neurotrauma management in rural and remote locations.

Restricting the time of injury in fatal inflicted head injuries

OBJECTIVE

To determine the normal clinical progression of fatal head injuries in children. Such information can then be used to estimate the time of injury in cases with obscure histories and will thus aid investigations of nonaccidental trauma.

METHOD

A retrospective chart review design was used. One hundred and thirty eight accidental fatalities involving head injury were identified and 95 of these were used as the study group. Details of the cases were reviewed and cases in which a child either had a Glasgow Coma Scale (GCS) of 14-15 or was described as having a "lucid interval" or as being "conscious" were further studied.

RESULTS

One "lucid interval" case was identified. This case involved an epidural hematoma. Three other cases that partially met the criteria for a lucid interval were also identified; one of these cases did not meet the criteria for inclusion in the study group. Review of head CTs revealed that brain swelling could be detected as early as 1 hour and 17 minutes post injury.

CONCLUSIONS

The children studied were in obvious serious medical condition from the time of injury until death. If a history purports a lucid interval in a fatal head injury case that does not involve an epidural hematoma, that history is likely false and the injury is likely inflicted. The time of most fatal head injury events can be restricted to the time period after the last confirmed period of wellness for the child. In addition, the presence of brain swelling on a head CT scan is not helpful in restricting the time of injury.

Head injuries in children and adults

Motor vehicle-related accidents account for the largest number of head injuries in all ages. This article reviews types of injury, neurologic assessment, secondary injury, brain swelling, seizures, resuscitation, and intensive care.

Variation in ED use of computed tomography for patients with minor head injury

STUDY OBJECTIVE

To determine the frequency of utilization, yield for brain injury, incidence of missed injury, and variation in the use of computed tomography (CT) for ED patients with minor head injury.

METHODS

This retrospective health records survey was conducted over a 12-month period in the EDs at seven Canadian teaching institutions. Included in this review were adult patients who sustained acute minor head injury, defined as witnessed loss of consciousness or amnesia and a Glasgow Coma Scale score of 13 or greater. Data were collected by research assistants who were trained to select cases and abstract data in a standardized fashion according to a resource manual. Subsequently, patient eligibility was reviewed by the study coordinator and principal investigator.

RESULTS

Of the 1,699 patients seen, 521 (30.7%) were referred for CT, and 418 (79.8%) of these scans were negative for any type of brain injury. Overall, 105 (6.2%) of these patients sustained acute brain injury, including 9 (.5%) with an epidural hematoma Cochran's Q test for homogeneity demonstrated significant variation between the seven centers for rate of ordering CT (P < .0001), from a low of 15.9% to a high of 70.4%. All five cases of "missed" hematoma occurred at the institutions with the highest and third highest rates of CT use. After controlling for possible differences in case severity and patient characteristics at each hospital, logistic regression analysis revealed that five of seven hospitals were significantly associated with the use of CT (respected odds ratios [OR], .4, .5, .5, 3.2, and 4.7). Three of the centers (two with the highest ordering rates) showed significant heterogeneity in the ordering of CT among their attending staff physicians, from a low of 6.5% to a high of 80.0%.

CONCLUSION

There was considerable variation among institutions and individual physicians in the ordering of CT for patients with minor head injury. Although emergency physicians were selective when ordering CT, the yield of radiography was very low at all hospitals. None of the cases of "missed" intracranial hematoma came from the lowest ordering institutions, indicating that patients may be managed safely with a selective approach to CT use. These findings suggest great potential for more standardized and efficient use of CT of the head, possibly through the use of a clinical decision rule.

Fibrinolytic parameters as an admission prognostic marker of head injury in patients who talk and deteriorate

Because it has been difficult to predict the outcome of patients with head injury in the early period after admission, a clinical study was undertaken to evaluate if the fibrinolytic parameters could be reliable indicators of outcome. Seventy patients presenting with head injury without obvious trauma in other regions were studied, and plasma levels of alpha2-plasmin inhibitor-plasmin complex (PIC) and D-dimer on admission (within 2 hours postinjury) were assessed. Plasma levels of both PIC and D-dimer were elevated and correlated well to patient outcomes. When plasma PIC levels were higher than 15 microg/ml or D-dimer levels were higher than 5 microg/ml, 92% of patients died regardless of their consciousness level on admission, whereas all patients made good recoveries when their PIC levels were less than 2 microg/ml or D-dimer levels were less than 1 microg/ml. Therefore, plasma levels of both PIC and D-dimer on admission were revealed to be reliable prognostic markers of head injury. Using these markers, patients with poor outcomes (progressive brain injury), such as "talk and deteriorate" types, could be readily identified on admission.

Prognostic factors in severely head injured adult patients with acute subdural haematoma's

A medline search back to 1975 was undertaken to identify relevant papers published on subdural haematomas. The search was restricted, whenever possible, to adult age and comatose patients. Forty relevant reports were identified. Only 3 papers reported results on multivariate analysis. In terms of prognosis, the following parameters were found to be significant: age, time from injury to treatment, presence of pupillary abnormalities, GCS/motor score on admission, immediate coma or lucid interval, CT findings (haematoma volume, degree of midline shift, associated intradural lesion, compression of basal cisterns), post-operative ICP and the type of surgery. Improving the outcome of patients with acute subdural haematoma's is a difficult task. A small subpopulation of patients may have a benign course without surgical haematoma evacuation, but all comatose patients with an acute subdural haematoma should be treated in Centers where neurosurgical facilities and appropriate monitoring are available.

Computed tomographic criteria and survival rate for patients with acute subdural hematoma

OBJECTIVE

Computed tomographic data from 174 patients with acute subdural hematoma were analyzed statistically to identify parameters that could be evaluated independently of clinical and neurological status to estimate outcome.

METHODS

This retrospective study was made necessary by the fact that the patients admitted usually had been treated with intubation, sedation, and artificial ventilation, which precludes neurological examination.

RESULTS

In surgically treated patients, the hematoma thickness ranged from 5 to 35 mm and the midline shift was 0 to 33 mm. In 81 patients (46.6%), the hematoma thickness was greater than the midline shift; in 24 patients (13.8%), the hematoma thickness equaled the midline shift; and in 69 patients (39.6%), the midline shift exceeded the hematoma thickness. Of the patients, 52% died after surgery, for 29% we obtained good or satisfying results, and 19% were in poor condition after therapy. The Kaplan-Meier survival analysis proved that the survival rate was only 50% for a hematoma thickness of approximately 18 mm and a midline shift of 20 mm. The survival function dropped markedly for midline shifts of more than 20 mm and converged to 0% for midline shifts of more than 25 mm. If the midline shift exceeded the hematoma thickness by 3 mm, the survival function was 50%; when the midline shift exceeded the hematoma thickness by 5 mm, the survival function was 25%. The Glasgow Outcome Scale scores were correlated significantly with these parameters. The parameters, which are the measured hematoma thickness, the midline shift, and the difference between the hematoma thickness and the midline shift, allow robust/adequate estimation of survival function and outcome for patients suffering from acute subdural hematoma.

CONCLUSION

Based on these data, indications for surgery could be assessed by means of video conferencing, i.e., without personal examination of the patients.

Diagnostic testing for the evaluation of headaches

Headaches are one of the most common symptoms that neurologists evaluate. Although most are caused by primary disorders, the list differential diagnoses is one of the longest in all of medicine, with over 300 different types and causes. The cause or type of most headaches can be determined by a careful history supplemented by a general and neurologic examination. Reasons for obtaining neuroimaging include medical indications as well as anxiety of patients and families and medico-legal concerns. In the era of managed care, concerns over deselection and negative capitation may dissuade the physician from ordering even a medically indicated scan. The yield of neuroimaging in the evaluation of patients with headache and a normal neurologic examination is quite low. Combining the results of multiple studies performed since 1977 for a total of 3026 scans reveals the overall percentages of various pathologies as: brain tumors, 0.8%; arteriovenous malformations, 0.2%; hydrocephalus, 0.3%; aneurysm, 0.1%; subdural hematoma, 0.2%; and strokes, including chronic ischemic processes, 1.2%. EEG is not useful in the routine evaluation of patients with headache. Similarly, the yield of neuroimaging in the evaluation of migraine is quite low. Combining the results of multiple studies performed since 1976 for a total of 1440 scans of patients with various types of migraine, the overall percentages of various pathologies are: brain tumor, 0.3%; arteriovenous malformation, 0.07%; and saccular aneurysm, 0.07%. WMA have been reported on MRI studies of patients with all types of migraine, with a range from 12% to 46%. The cause of WMA in migraine is not certain. Cerebral atrophy has been variable reported as more frequent and no more frequent in migraineurs compared with controls. The "first or worst" headache has a long list of possible causes and always includes the possibility of acute subarachnoid hemorrhage. Headaches--especially the sentinel type caused by SAH--often are misdiagnosed. The probability of detecting an aneurysmal hemorrhage of CT scans performed at various intervals after the ictus is: day 0.95%; day 3, 74%; 1 week, 50%; 2 weeks, 30%; and 3 weeks, almost nil. The location of a ruptured saccular aneurysm often is suggested by the predominant site of the SAH. The probability of detecting xanthochromia with spectrophotometry in the CSF at various times after a subarachnoid hemorrhage is: 12 hours, 100%; 1 week, 100%; 2 weeks, 100%; 3 weeks, more than 70%; and 4 weeks, more than 40%. The management of thunderclap headaches with normal CT scan and CSF examinations is controversial. Most patients have a benign course but an unruptured saccular aneurysm occasionally may be responsible for the headache. MR angiography may be a reasonable test to obtain instead of a cerebral arteriogram in many of these cases. About 30% to 90% of patients have headaches of various types and causes after mild head injury. Although most headaches are relatively benign, perhaps 1% to 3% of these patients have life-threatening pathology, including subdural and epidural hematomas, that are detected on CT and MRI scans. Headaches caused by subdural hematomas can be nonspecific. When new-onset headaches begin in patients over the age of 50 years, the physician always should consider whether it may be a secondary headache disorder requiring specific diagnostic testing and treatment. Up to 15% of patients 65 years and over who present to neurologists with new-onset headaches may have serious pathology such as stroke, TA, neoplasm, and subdural hematoma. Headaches are the most common symptom of TA, reported by 60% to 90%. The only over the temple. The diagnosis of TA is based on a high index of clinical suspicion that usually but not always is confirmed by laboratory testing. The erythrocyte sedimentation rate can be normal in 10% to 36% of patients with TA. A superficial temporal artery biopsy can give a false-negative result in 5% to 44% of patients.

CT and clinical criteria for conservative treatment of supratentorial traumatic intracerebral haematomas

In search of guidelines for the management of traumatic intracerebral haematomas (TICHs) with slight mass effects on computed tomography (CT) scans, the author reviewed the records of 29 patients who did not undergo surgery and 11 patients who did. It is found that patients with a TICH volume of less than 15 ml, a midline shift of less than 5 mm, an open perimesencephalic cistern on CT scans, a Glasgow Coma Scale (GCS) score of 12 or more, and an absence of lateralizing signs may be treated conservatively and expected to make a good recovery. On the other hand, with zero mortality and satisfactory outcomes, the patients under-going early surgery tended to have a TICH volume of more than 15 ml, a midline shift of more than 5 mm, an obliterated perimesencephalic cistern on CT scans, a GCS score of less than 12, and the presence of lateralizing signs. However, the position of such features as the criteria of early operation for a TICH is weakened by the retrospective nature of this study because some surgical patients, free of lateralizing signs in particular, might have managed to do well without craniotomy.

Head injury mechanisms and the concept of preventive management: a review and critical synthesis

Recent advances in head injury research have produced a plethora of useful data coupled with a paucity of conceptual integration across the four ways in which this research is pursued. These research orientations are the epidemiological, biomechanical, basic neuroscientific, and clinicopathologic/therapeutic (including rehabilitation). This overview of the history and current state of the art assumes that biomechanics is the basic science of causation in head injury research and when fully integrated with its counterparts, physiology and pathology, it can serve to overcome our conceptual handicaps. A paradigm integrating biomechanics; into the sequence of preventive, protective, acute therapeutic, and rehabilitative interventions will be described as the concept of preventive management. From this we derive the hypothesized claim that the exact biomechanics and the physiopathologic response at the time of injury (at the macroscopic and microscopic levels) determine the sequence of so-called secondary effects that are conceived as the inexorable delayed manifestations of the primary events and concomitant boundary conditions. Knowledge of these events will enable accurate predictions of the natural history and outcome of head injuries from observations carried out in the early acute phase. Examples to test this claim will be given with particular reference to the two types of traumatic brain injury (TBI) phenomenologically associated with disturbances of consciousness, the onset of which can be either immediate or delayed. The current economics and availability of computational power provide a significant opportunity for the development of selected experimental, physical, and simulated models of head injury on the basis of which the complex neurovascular and nonneural cellular and fluid elements of the nervous system may be accurately modeled. This approach will significantly improve the efficiency and quality of the essential biological and clinical observations and model experiments required to validate the theoretical methods and their predictions.

Criteria for conservative treatment of supratentorial acute subdural haematomas

Without mortality, 31 patients underwent conservative treatment for traumatic supratentorial acute subdural haematoma (SDH). Later on six of them had the haematoma surgically evacuated mainly because of a deterioration of the Glasgow Coma Scale (GCS) scores. It was found that patients with a midline shift of less than 10 mm on the computed tomography (CT) scans and with a GCS score of 15 initially might be treated conservatively under close observation, reserving urgent craniotomy and evacuation of the SDH for those with deteriorating neurological conditions. A smaller degree of midline shift was tolerated by patients with an GCS score of less than 15: a shift of more than 5 mm on the initial CT scans predicted an exhaustion of the cerebral compensatory mechanism within 3 days of injury. In such cases the GCS score worsened, and surgical evacuation of the SDH became necessary. A total hospital stay of 6 to 7 days may suffice for those who have become fully conscious. Repeat CT studies before discharge should be done and a close follow-up during the first 3 to 4 weeks is advisable.

Early cerebrovascular response to head injury in immature and mature rats

Clinical studies suggest that children respond to head injury with more pronounced cerebral edema and hyperemia than do adults. We hypothesized that these age-related differences could be demonstrated in an animal model. Anesthetized and ventilated mature (2-3 months) and immature (3.5-4.5 weeks) male Wistar rats were traumatized by weight drop onto the exposed right parietal cortex. Trauma severity was adjusted to keep the ratio of force to brain weight constant. This resulted in an energy delivered to the brain of about 9 x 10(3) ergs.mm-2.g-1 brain in both age groups. Percent right hemispheric brain water (%RBW) was measured at 2, 24, 48, and 168 h posttrauma. Infarct area, intracranial pressure (ICP), and 14C-iodoantipyrine autoradiographic local cerebral blood flow (ICBF) were measured at 2 h or 24 h posttrauma. In mature rats, %RBW was unchanged at 2 h, but increased at 24 and 48 h (both p < 0.05). In immature rats, %RBW increased at 2 h and remained elevated at 24 and 48 h (all p < 0.05). Traumatic infarct area as a percent of hemispheric area at 24 h did not differ between age groups. In mature rats, at 2 h posttrauma ICBF was reduced (p < 0.05) in 16 of 17 regions but in only 4 of 17 regions in immature rats. ICBF as a percent of age-matched control values showed a greater reduction in mature vs immature rats in 9 of 16 regions (p < 0.05). ICP increased at 24 h posttrauma in both age groups. In immature rats posttrauma, brain water increased earlier and cerebral hypoperfusion was less marked than in mature rats.