Traumatic subarachnoid hemorrhage as a predictable indicator of delayed ischemic symptoms

Posttraumatic basilar artery vasospasm

BACKGROUND

During the past decade, vasospasm following posttraumatic subarachnoid hemorrhage (tSAH) has drawn increasing attention. However, despite accumulating evidence linking this phenomenon with poorer outcome, the clinical significance of posttraumatic vasospasm is still debated and often disputed, so that no definite therapeutic attitude has yet been adopted. Recent attention has been drawn to basilar vasospasm, suggesting a negative influence on neurologic outcome. The aim of the present study was the evaluation of basilar vasospasm as an independent factor of secondary brain damage following posttraumatic hemorrhage.

METHODS

Daily transcranial Doppler (TCD) evaluations were conducted in 93 consecutive patients with tSAH. Basilar artery (BA) vasospasm was defined by blood flow velocity (FV) higher than 85 cm/s for at least 2 consecutive days.

RESULTS

Thirty-two patients (34.4%) had BA FVs higher than 85 cm/s. In those patients, the ratio between BA FV and mean vertebral artery FV was higher than 2.5 and below 2 and those without TCD signs of vasospasm. Using multivariate logistic regression analysis, BA vasospasm proved to independently influence neurologic outcome.

CONCLUSIONS

BA vasospasm severe enough to compromise cerebral blood flow to the brainstem, although uncommon, may nevertheless have a potential deleterious effect on neural tissue sensitized by trauma. The present results suggest that specific imaging procedures and eventually therapeutic measures should be conducted in the presence of significant BA vasospasm.

Evolving lesions in traumatic subarachnoid hemorrhage: prospective study of 110 patients with emphasis on the role of ICP monitoring

We have consecutively studied 110 patients with traumatic subarachnoid hemorrhage (tSAH) on the first Computed Tomography (CT) scan (obtained in each case within 3 hours from injury). The only exclusion criteria were brain death on admission, and severe hypotension due to extracranial injuries. All CTs were reviewed by one of us and the "worst" CT examination was determined. We defined the worst CT examination as that showing the most extensive degree of parenchymal-associated damage. Intracranial pressure was monitored in 25 severely head injured patients. Seventy-four patients (66%) showed an evolution from the initial CT scan (worst CT not corresponding to the admission CT). The outcome was favorable in 53 cases (73%) of patients with evolving lesions and in 32 cases (89%) with non evolving lesion. In the 25 severely head injured patients, Intra-cranial Pressure (ICP) monitoring (in combination with scheduled repeat CT scan) was helpful to identify the timing of the worst parenchymal damage and of surgery in those patients with an initial normal intracranial pressure in spite of an evolving lesion.

Traumatic subarachnoid hemorrhage on the computerized tomography scan obtained at admission: a multicenter assessment of the accuracy of diagnosis and the potential impact on patient outcome

OBJECT

The goal of this study was fourfold: 1) to determine the incidence of traumatic subarachnoid hemorrhage (tSAH) in patients with traumatic brain injury (TBI); 2) to verify agreement in the diagnosis of tSAH in a multicenter study; 3) to assess the incidence of tSAH on the outcome of the patient; and 4) to establish whether tSAH itself leads to an unfavorable outcome or whether it is a sign of major brain trauma associated with severe posttraumatic lesions.

METHODS

Computerized tomography (CT) scans obtained in 169 head-injured patients on admission to 12 Italian intensive care units during a 3-month period were examined. The scans were collected for neuroradiological review and were used for the analysis together with data from a multicenter database (Neurolink). A review committee found a high incidence of tSAH (61%) in patients with TBI and a moderate agreement among centers (K = 0.57). Significant associations were observed between the presence and grading of tSAH and patient outcomes, and between the presence of tSAH and the severity of the CT findings. Logistic regression analysis showed that the presence of tSAH and its grading alone do not assume statistical significance in the prediction of unfavorable outcome.

CONCLUSIONS

Traumatic SAH frequently occurs in patients with TBI, but it is difficult to detect and grade. Traumatic SAH is associated with more severe CT findings and a worse patient outcome.

Traumatic subarachnoid hemorrhage: demographic and clinical study of 750 patients from the European brain injury consortium survey of head injuries

OBJECTIVE

Previous reports identified the presence of traumatic subarachnoid hemorrhage (tSAH) on admission computed tomographic (CT) scans as an independent prognostic factor in worsening outcomes. The mechanism underlying the link between tSAH and prognosis has not been clarified. The aim of this study was to investigate the association between CT evidence of tSAH and outcomes after moderate or severe head injuries.

METHODS

In a survey organized by the European Brain Injury Consortium, data on initial severity, treatment, and subsequent outcomes were prospectively collected for 1005 patients with moderate or severe head injuries who were admitted to one of the 67 European neurosurgical units during a 3-month period in 1995. The CT findings were classified according to the Traumatic Coma Data Bank classification system, and the presence or absence of tSAH was recorded separately in the initial CT scan forms.

RESULTS

Complete data on early clinical features, CT findings, and outcomes at 6 months were available for 750 patients, of whom 41% exhibited evidence of tSAH on admission CT scans. There was a strong, highly statistically significant association between the presence of tSAH and poor outcomes. In fact, 41% of patients without tSAH achieved the level of good recovery, whereas only 15% of patients with tSAH achieved this outcome. Patients with tSAH were significantly older (median age, 43 yr; standard deviation, 21.1 yr) than those without tSAH (median age, 32 yr; standard deviation, 19.5 yr), and there was a significant tendency for patients with tSAH to exhibit lower Glasgow Coma Scale scores at the time of admission. A logistic regression analysis of favorable/unfavorable outcomes demonstrated that there was still a very strong association between tSAH and outcomes after simultaneous adjustment for age, Glasgow Coma Scale Motor Scores, and admission CT findings (odds ratio, 2.49; 95% confidence interval, 1.74-3.55; P < 0.001). Comparison of the time courses for 164 patients with early (within 14 d after injury) deaths demonstrated very similar patterns, with an early peak and a subsequent decline; there was no evidence of a delayed increase in mortality rates for either group of patients (with or without tSAH).

CONCLUSION

These findings for an unselected series of patients confirm previous reports of the adverse prognostic significance of tSAH. The data support the view that death among patients with tSAH is related to the severity of the initial mechanical damage, rather than to the effects of delayed vasospasm and secondary ischemic brain damage.

Morphological presentation of posttraumatic vasospasm

Posttraumatic vasospasm is a well-recognized sequela of head injury. The risk factors associated with posttraumatic vasospasm have not been well defined. We studied 119 consecutive patients with head injury to determine the risk factors for posttraumatic vasospasm. Posttraumatic vasospasm was detected in 32 (35.6%) of 90 patients. Among these patients, 29 (90.6%) had severe head injury and 3 (9.4%) had moderate head injury. None of the patients with mild head injury suffered posttraumatic vasospasm. In most cases, the onset of posttraumatic vasospasm began on the fifth day and lasted 1 to 9 days. In 8 (25%) patients, posttraumatic vasospasm began within the first three days of the head injury. Clinical deterioration was documented in two (2.5%) patients. Morphologically, posttraumatic vasospasm resembled features of aneurysmal vasospasm. We found increased corrugation of the internal elastic lamina and increased amounts of connective tissue in the subendothelial layer. These findings showed that posttraumatic vasospasm, although clinically more mild, demonstrated the same morphological changes as did aneurysmal vasospasm.

Risk factors for the development of post-traumatic cerebral vasospasm

BACKGROUND

Post-traumatic vasospasm is a well-recognized sequela of head injury. The risk factors associated with post-traumatic vasospasm have not been well defined. We studied 119 consecutive patients with head injury to determine the risk factors for post-traumatic vasospasm.

METHODS

Twenty-nine (27.1%) patients were excluded from the study because of poor insonation (n = 12) or a hospital stay of less than 72 hours (n = 17). Seventy (77.8%) of 90 patients suffered severe head injury. Sixteen (17.8%) patients sustained moderate head injury and four (4.4%) patients sustained mild head injury. All patients were monitored with transcranial Doppler (TCD) ultrasonography daily.

RESULTS

Post-traumatic vasospasm was detected in 32 (35.6%) of 90 patients. Among these patients, 29 (90.6%) had severe head injury, and three (9.4%) had moderate head injury. None of the patients with mild head injury suffered post-traumatic vasospasm. In most cases, the onset of post-traumatic vasospasm began on the fifth day and lasted 1 to 9 days. In 8 (25%) patients, post-traumatic vasospasm began within the first three days of the head injury. Among 32 patients with post-traumatic vasospasm, 10 (31.2%) patients had mild vasospasm, 20 (65.5%) had moderate vasospasm, and 2 (6.3%) had severe post-traumatic vasospasm. Clinical deterioration was documented in two (2.5%) patients.

CONCLUSIONS

Development of post-traumatic vasospasm correlated only with severe subarachnoid hemorrhage on initial computed tomographic scan. There was an increased incidence of post-traumatic vasospasm in patients with epidural hematomas, subdural hematomas, and intracerebral hemorrhages. The Glasgow Coma Scale (GCS) score on admission was inversely related to the development of post-traumatic vasospasm. In most cases, the period of vasospasm was short and clinical deterioration was rare. Probably, two varieties of post-traumatic vasospasm exist, one that lasts a shorter time and does not correlate with the presence of SAH, and a second that correlates with the presence of SAH, lasts longer, and resembles aneurysmal vasospasm.

Posttraumatic cerebral vasospasm: clinical and morphological presentations

Head injury is one of the leading causes of morbidity and mortality in the young population. Many factors complicate head injury and worsen an outcome. One of these factors is posttraumatic cerebral vasospasm. We studied 75 patients admitted to the University of Mississippi Medical Center with head injury. Their ages ranged from 14 to 67 years (mean 30 years, SD 11.63). Eighty percent of the patients were men, and 20% were women. Of these patients, 53 (70.6%) suffered severe blunt trauma, and 4 patients suffered gunshot wounds to the head. Four patients had mild head injury, and 14 had moderate head injury. Posttraumatic vasospasm was detected in 24 (32%) patients. Among these patients, 19 (79.2%) had severe closed head injury, 3 patients had moderate head injury, and 2 suffered gunshot wounds. The severity of the patient's respective condition was correlated with the development of posttraumatic cerebral vasospasm: 50% of the patients with Glasgow Coma Scale (GCS) 3-4 developed PTV, and only 30% with GCS 9-11, and none of the patients with GCS > 12 developed PTV. Overall, posttraumatic vasospasm started earlier and had a shorter course than did aneurysmal vasospasm. Morphologically, posttraumatic vasospasm resembled the features of aneurysmal vasospasm. We found increased corrugation of the internal elastic lamina and increased amounts of connective tissue in the subendothelial layer. These findings show that posttraumatic vasospasm, although clinically more mild, demonstrates the same morphological changes as aneurysmal vasospasm.

Etiology of cerebral vasospasm

Cerebral vasospasm is a gradual onset and prolonged constriction of the cerebral arteries in the subarachnoid space after subarachnoid hemorrhage. The principal cause is the surrounding blood clot. The significance of vasospasm is that flow through the constricted arteries may be reduced sufficiently to cause cerebral infarction. Subarachnoid blood clot is sufficient to cause vasospasm; it does not require additional arterial injury, intracranial hypertension or brain infarction, although these elements are often coexistent. The blood released at the time of aneurysmal rupture into the alien subarachnoid environment is an extraordinarily complex mix of cellular and extracellular elements that evolves as clotting occurs; cells disintegrate; local inflammation, phagocytosis and repair take place; severe constriction alters the metabolism and structure of the arterial wall as well as the balance of vasoconstrictor and dilator substances produced by its endothelium, neurogenic network and perhaps smooth muscle cells.

Subarachnoid hemorrhage in rats: effect of singular or sustained hemodilution with alpha-alpha diaspirin crosslinked hemoglobin on cerebral hypoperfusion

OBJECTIVE

To evaluate the effect of singular or sustained hemodilution, with alpha-alpha diaspirin crosslinked hemoglobin (DCLHb), on the area of hypoperfusion after subarachnoid hemorrhage.

DESIGN

Prospective animal study.

SETTING

Animal research laboratory.

SUBJECTS

Isoflurane anesthetized, mechanically ventilated rats.

INTERVENTIONS

Subarachnoid hemorrhage was induced by injecting 0.3 mL of blood into the cisterna magna. The animals were randomly assigned to one of the following groups (n = 16 in each hemodilution group; eight animals received a single treatment of hemodilution after subarachnoid hemorrhage; and, for eight animals, treatment was sustained for 48 hrs): control group (n = 8), no hematocrit (45%) manipulation; DCLHb group (n = 16), hematocrit decreased to 30% with DCLHb; or Alb group (n = 16), hematocrit decreased to 30% with human serum albumin. After 48 hrs, the area of hypoperfusion (cerebral blood flow < 40 ml/100g/min) was determined with 14C-iodoantipyrine in five coronal brain sections.

MEASUREMENTS AND MAIN RESULTS

For both singular and sustained treatment, the area of hypoperfusion was less in both hemodilution groups than in the control group (p<.05). For four of the five coronal brain sections, no differences were found between the DCLHb and Alb groups within a given hemodilution protocol. In addition, in four of the five coronal brain sections for the DCLHb hemodilution groups and in all five sections for the albumin hemodilution groups, the area of hypoperfusion was less for rats that received sustained hemodilution compared with their respective groups in the singular treatment protocol (p<.05).

CONCLUSIONS

These data support the hypothesis that hemodilution with molecular hemoglobin decreases hypoperfusion after subarachnoid hemorrhage and that sustained hemodilution is more effective than singular treatment. The data do not support the notion that intravascular DCLHb has an adverse effect on cerebral ischemia after subarachnoid hemorrhage.

Does traumatic subarachnoid hemorrhage caused by diffuse brain injury cause delayed ischemic brain damage? Comparison with subarachnoid hemorrhage caused by ruptured intracranial aneurysms

OBJECTIVE

To examine whether traumatic subarachnoid hemorrhage (TSAH) caused by severe diffuse brain injury leads to delayed ischemic brain damage and secondary deterioration of outcome, as does aneurysmal subarachnoid hemorrhage (ASAH).

METHODS

We examined 99 patients with diffuse brain injury with TSAH and 114 patients with ASAH. Computed tomographic (CT) findings, cerebral blood flow, and neurological outcomes were assessed during the acute and subacute phases and were compared between the two groups.

RESULTS

The distribution of subarachnoid hemorrhage on the CT scans differed between the two groups. Unlike ASAH, TSAH was not limited to cisterns surrounding the circle of Willis but extended to supratentorial regions and interhemispheric fissures. Computed tomography-detected subarachnoid hemorrhage disappeared very early with TSAH and gradually with ASAH. In the ASAH group, mean cerebral blood flow decreased to 75% of normal during the acute phase and decreased a further 10% during the subacute phase. In the TSAH group, mean cerebral blood flow decreased to 85% of normal during the acute phase and increased slightly during the subacute phase. Neurological deterioration and in-hospital death peaked on Day 0 in association with TSAH and showed twin peaks in association with ASAH. The incidence of low-density areas on the CT scans was significantly higher with ASAH than with TSAH. All low-density areas on the CT scans of patients with ASAH corresponded to vascular territories, but low-density areas on the CT scans of patients with TSAH were rarely associated with vascular territories and contained deep-seated or gliding contusion types.

CONCLUSION

The findings suggest that the incidence of vasospasm is low in association with TSAH and that the cause is different compared with ASAH. There is no evidence that the presence of TSAH in cases of diffuse brain injury leads to delayed ischemic brain damage and secondary deterioration of outcome.

Transcranial Doppler in vertebrobasilar vasospasm after subarachnoid hemorrhage

OBJECTIVE

The primary objective of this study was to assess the incidence of vertebrobasilar vasospasm after subarachnoid hemorrhage (SAH) by means of transcranial Doppler ultrasonography and to evaluate the clinical significance of this phenomenon. The secondary objective was to analyze the different factors influencing the development, the severity, and the duration of vertebrobasilar vasospasm.

METHODS

Fifty-seven patients with traumatic SAH and 44 patients with spontaneous SAH were evaluated and monitored by means of transcranial Doppler ultrasonography. Vasospasm of the anterior and middle cerebral arteries was defined by mean flow velocities (FVs) exceeding 120 cm per second and at least three times the FV of the internal carotid artery. Vasospasm of the basilar and vertebral arteries was defined by a mean FV exceeding 60 cm per second.

RESULTS

Vasospasm of the anterior or middle cerebral arteries was found in 27 patients and was associated with vertebrobasilar spasm in 20 patients. FVs in anterior circulation vessels were neither related to the cause of the SAH nor did they correlate with the outcome. Forty-six patients (45.5%) had FVs exceeding 60 cm per second and 25 (24.8%) had FVs exceeding 85 cm per second. In 10 of these patients, direct or computed tomographic angiography showed arterial narrowing involving the vertebrobasilar system, whereas in 21 more patients, computed tomography disclosed a cerebral infarction involving the vertebrobasilar vascular territory. Vertebral artery FVs in this group were twice that of the ipsilateral carotid artery. Vertebrobasilar vasospasm was significantly more frequent after head injury, although it was not related to the type of intracranial lesion or the Glasgow Coma Scale score at admission. It did correlate, however, with outcome (P < 0.0001) and with the intensity of SAH (P < 0.0001). Delayed neurological deterioration occurred in 14 patients and was significantly more frequent in patients with basilar artery FVs above 85 cm per second (P < 0.001). Prognosis, however, could not be reliably predicted by FVs in the basilar artery, even when an FV of 110 cm per second was chosen for prediction criterion.

CONCLUSION

These results suggest that vertebrobasilar vasospasm is more common than previously thought, especially in association with head injury, with which it may significantly contribute to brain stem ischemic lesions and therefore justify specific therapeutic measures.

Changes in cerebral blood flow during PaCO2 variations in patients with severe closed head injury: comparison between the Fick and transcranial Doppler methods

OBJECT

The aim of this study was to reassess whether middle cerebral artery blood flow velocity (MCAv) variations measured by transcranial Doppler ultrasonography during acute PaCO2 manipulation adequately reflect cerebral blood flow (CBF) changes in patients with severe closed head injury.

METHODS

The study was performed by comparing MCAv variations to changes in CBF as assessed by measurements of the difference in the arteriovenous content in oxygen (AVDO2). The authors initiated 35 CO2 challenges in 12 patients with severe closed head injury during the acute stage. By simultaneous recording of systemic and cerebral hemodynamic parameters, 105 AVDO2 measurements were obtained. Patients were stratified into two groups, "high" and "low," with respect to whether their resting values of MCAv were greater than 100 cm/second during moderate hyperventilation. Four patients displayed an elevated MCAv, which was related to vasospasm in three cases and to hyperemia in one case. The PaCO2 and intracranial pressure levels were not different between the two groups. The slope of the regression line between 1 divided by the change in (delta)AVDO2 and deltaMCAv was not different from identity in the low group (1/deltaAVDO2 = 1.08 x deltaMCAv - 0.07, r = 0.93, p < 0.001) and significantly differed (p < 0.05) from the slope of the high group (1/deltaAVDO2 = 1.46 x deltaMCAv - 0.4, r = 0.83, p < 0.001).

CONCLUSIONS

In patients with severe closed head injury, MCAv variations adequately reflect CBF changes as assessed by AVDO2 measurements in the absence of a baseline increase in MCAv. These observations indicate that both moderate variations in PaCO2 and variations in cerebral perfusion pressure do not act noticeably on the diameter of the MCA. The divergence from the expected relationship in the high group seems to be due to the heterogeneity of CO2-induced changes in cerebrovascular resistance between differing arterial territories.

Plasma levels of protein C, protein S, and antithrombin III in patients with subarachnoid haemorrhage

This study was designed to evaluate the clinical value of consecutive measurements of the levels of the anticoagulation factors protein C. protein S and antithrombin III in the plasma of patients with subarachnoid haemorrhage (SAH). Sequential samples of plasma were obtained from 34 patients at days 0 to 3, 5, 8, 14, and 20 days after SAH. Their levels of protein C, protein S and antithrombin III were measured by specific immuno-assays, and the symptomatic vasospasm and clinical states of the patients were monitored. Based on the retrospective comparisons between the measured levels of the three factors and the levels in pooled plasma from normal volunteers, the time course of changes in the levels allowed the classification of the patients into five groups as follows: A, the levels of the three factors decreased suddenly at 5 days after SAH, then increased again (n = 6); B, the three factors increased continuously (n = 13); C, the three factors remained below the normal range (n = 3); D, the three factors remained within the normal range (n = 6); and E, the three factors decreased continuously (n = 6). In group A patients, temporary deficiencies in the three factors occurred that coincided with the occurrence of delayed neurological deficit (DND). Twelve patients (92%) in group B had a favourable outcome (good and moderate disability) without DND. The patients in group C had low levels of anticoagulation factors and mild DND followed by a favourable outcome. Five patients (83%) in group D had a favourable outcome. In group E, five patients (83%) had a poor outcome (severe disability and death) due to DND. When clinical outcomes were compared by patient group, the patients in group E had significantly more unfavourable outcomes than did the other groups (P < 0.01). Although the mechanism responsible for the decrease in anticoagulation factor levels remained unclear, the results suggested that the decrease in anticoagulation factors may indicate hypercoagulability and cerebral ischaemia after SAH.