Traumatic Acute Subdural Hematoma Research Articles

Long-term quality of life outcome (SF-36) in traumatic acute subdural hematoma patients

Long-term quality of life outcome (SF-36) in traumatic acute subdural hematoma patients

Diffusion-weighted magnetic resonance imaging in a case of Kernohan's notch phenomenon

Dear Editor, Kernohan's notch phenomenon is characterized by false localizing motor signs caused by compression of the cerebral peduncle against the tentorial edge, contralateral to a supratentorial mass [3]. Using magnetic resonance imaging (MRI), several cases of this phenomenon due to traumatic acute subdural hematomas were reported. A case of Kernohan's notch phenomenon with diffusionweighted (DW) MRI in a chronic stage was reported before [5]. We present a case of Kernohan's notch phenomenon secondary to a traumatic acute subdural hematoma where MRI, mainly DW images, showed visibly abnormal findings in the early subacute stage. A 19-year-old male felt nauseous after boxing. Soon afterwards he became unconscious following which he was transferred to a local hospital. After being diagnosed with an acute subdural hematoma (Fig. 1a), he was intubated and transferred to our hospital. In the emergency room his Glasgow Coma Scale score was 7. He was able to move his right extremities but his left extremities exhibited an extended posture. Light reflex of the left pupil was sluggish. Babinski signs were negative bilaterally. Subsequently, a left craniotomy was performed with evacuation of the subdural hematoma 6 h after the onset. Postoperatively, his pupillary reaction normalized. He began to regain consciousness and gradually the right motor function improved; however, the left hemiplegia persisted. After 21 days, the patient had persistent left hemiparesis and was transferred to another hospital for rehabilitation. MRI (1.5 T Philips Intera) performed 7 days after the operation revealed that the subdural hematoma was successfully evacuated. However, T2-weighted MRI revealed a lesion in the right cerebral peduncle (Fig. 1b, c). Furthermore, DW imaging (EPI Matrix 256×256, FOV=230 mm, TR/TE=2721/72 ms, b=1,000 mm/s, thickness=5 mm) revealed the lesion to be hyperintense (Fig. 1d). The apparent diffusion coefficient (ADC) map showed the area as a low signal (Fig. 1e), and it had a relatively low ADC value (0.78×10 mm/s) compared to that of the contralateral cerebral peduncle (0.90×10 mm/s). Besides conventional MRI, Binder et al. first reported Kernohan's notch phenomenon with transcranial magnetic stimulation [2]. Later Yoo et al. reported a case of Kernohan's notch phenomenon with diffusion tensor imaging, which is the only published case where DW imaging was used [5], here, MRI was performed 6 weeks after the onset, fraction anisotropy (FA) and ADC values were shown but DW image was not included. The FA value decreased in the affected cerebral peduncle, but a marked difference was not seen between ADC values on the contralateral side or in the control subjects. Marmarou, Barzo et al. conducted clinical and experimental studies on traumatized brains. They reported that increased intracellular water volume and reduced ADC value indicates cytotoxic edema. During the subacute stage, axonal injury causes a reduced ADC value after traumatic S. Uesugi (*) Department of Neurosurgery, Kanmon Medical Center, 1-1 Sotouracho, Chofu, Shimonoseki, Yamaguchi 7520985, Japan e-mail: uesugis@simonoseki2.hosp.go.jp

Interhemispheric chronic subdural haematoma: Case report and brief review of the literature

Background: Chronic subdural haematoma usually arises from a traumatic acute haemorrhage in the subdural space, frequently causing mass effect and consequent neurological decline. This lesion is mainly found over the cortical convexity and its evolution and surgical approach has been extensively studied. Nevertheless, inter-hemispheric chronic subdural haematoma is considered a rare lesion.Aim and case report: This study reported a case of traumatic acute interhemispheric subdural haematoma, initially asymptomatic, and its evolution to a chronic symptomatic lesion, as well as the surgical approach employed. A brief review of the literature is presented with a discussion of the therapeutic options.

Contralateral Acute Subdural Hematoma After Surgical Evacuation of Acute Subdural Hematoma

We present a case of an 81-year-old woman who developed an acute left-sided subdural hematoma with midline shift shortly after craniotomy for evacuation of a traumatic right-sided acute subdural hematoma. She was immediately taken back to the operating room for evacuation of the left-sided clot and her neurologic outcome was excellent. Believed to be caused by rapid brain decompression, bleeding far from the operative site, such as a within the contralateral subdural space, can occur after a craniotomy and must be promptly recognized.

Management and outcome of patients with acute traumatic subdural hematomas and pre-injury oral anticoagulation therapy

Background: Acute subdural hematomas (aSDHs) are found in up to one-third of patients with severe traumatic brain injury and are associated with an unfavorable outcome in the majority of cases. Mortality ranges between 40 and 60%, but was reported to be even higher in patients undergoing oral anticoagulation therapy (OAT) at the time of injury. The objective of this study is to specifically report on the peri-operative management and outcome of patients with aSDH and pre-injury OAT.Material and Methods: From June 2002 to June 2006, all patients with OAT who underwent surgical treatment of aSDH were retrospectively analysed. Results of pre-operative blood tests, the peri-operative and surgical management and the clinical courses were assessed. Patient outcome is reported according to the Glasgow Outcome Scale (GOS) at 6 months.Results: Eleven (10.3%) out of 107 patients with aSDH were on OAT. Patients with OAT were significantly older than patients without OAT (72.4 ± 9.3 versus 59.9 ± 17.5 years; p<0.05, Mann–Whitney U-test). Intensity of head trauma was moderate in four and severe in seven patients with a median pre-operative Glasgow Coma Scale (GCS) of 8. Median pre-treatment prothrombin time and international normalized ratio were 23% (range: 10–65%) and 3.3 (range: 1.5–10.6), respectively. Replacement therapy consisted of administration of prothrombin complex concentrates, vitamin K and FFP (fresh frozen plasma). In four patients, antithrombin was additionally given to prevent disseminated intravascular coagulation. Surgical treatment consisted of craniotomy (n=10) or craniectomy (n=1) and hematoma evacuation with intracranial pressure probe placement. Low molecular weight heparin was administered as pharmacological prophylaxis of thrombembolic events in an increasing dose post-operatively. At 6 months, six out of 11 patients survived with a median GOS of 4. All-cause mortality was 45.5%. A pre-operative GCS of ≤ 8 was not associated with an increased risk of mortality (p>0.5, Fisher's exact test). No relevant rebleedings or thrombembolic complications were observed. The mortality rate of patients who did not undergo OAT was 50%.Conclusion: A large number of patients with aSDH are on pre-injury OAT. Specific replacement therapy facilitates successful clot evacuation without bleeding complications. The overall outcome of these patients does not seem to differ from historical cohorts with aSDH without OAT, but a large prospective multicenter study is warranted to answer that question.

Gerıatrıc Traumatıc Acute Subdural Haematomas: A Retrospectıve Study

Objective:Acute subdural hematomas (ASDH) are severe traumatic brain injuries. Older patients have a higher mortality rate.We retrospectively reviewed 19 geriatric patients with ASDH to demonstrate the outcome of the management of ASDH and to find out which parameters are significant in predicting the outcome. Methods:Computer records and patient files of 19 geriatric patients with traumatic ASDH who underwent surgical intervention in OndokuzMayis University School of Medicine at Department of Neurosurgery between January 2006-December 2009 were reviewed.The diagnosis was based on computerized tomography (CT) findings.Examined criteria were age, sex , mechanism of the trauma, Glasgow Coma Score (GCS )on admission , presence of a midline shift and contusio cerebri , thickness of the haematoma , accompanying chronic diseases , anticoagulant therapy , type of surgery and neurological examination on discharge.ASDH of the posterior fossa , subacute-chronic subdural haematomas , patients with serious extracranial injuries and aged below 65 were excluded. Results:A GCS of ≤ 8 on initial presentation,pupillary non reactivity,presence of a midline shift and contusio cerebri was found to be significantly associated with increased mortality and a poor patient outcome.Effect of sex,anticoagulant therapy and type of surgery couldn’t have been found to be determinant on prognosis.

Predictors for Functional Recovery and Mortality of Surgically Treated Traumatic Acute Subdural Hematomas in 256 Patients

The purpose of this study was to investigate the reliable factors influencing the surgical outcome of the patients with traumatic acute subdural hematoma (ASDH) and to improve the functional outcome of these patients. A total of 256 consecutive patients who underwent surgical intervention for traumatic ASDH between March 1998 and March 2008 were reviewed. We evaluated the influence of perioperative variables on functional recovery and mortality using multivariate logistic regression analysis. Functional recovery was achieved in 42.2% of patients and the overall mortality was 39.8%. Age (OR=4.91, p=0.002), mechanism of injury (OR=3.66, p=0.003), pupillary abnormality (OR=3.73, p=0.003), GCS score on admission (OR=5.64, p=0.000), and intraoperative acute brain swelling (ABS) (OR=3.71, p=0.009) were independent predictors for functional recovery. And preoperative pupillary abnormality (OR=2.60, p=0.023), GCS score (OR=4.66, p=0.000), and intraoperative ABS (OR=4.16, p=0.001) were independent predictors for mortality. Midline shift, thickness and volume of hematoma, type of surgery, and time to surgery showed no independent association with functional recovery, although these variables were correlated with functional recovery in univariate analyses. Functional recovery was more likely to be achieved in patients who were under 40 years of age, victims of motor vehicle collision and having preoperative reactive pupils, higher GCS score and the absence of ABS during surgery. These results would be helpful for neurosurgeon to improve outcomes from traumatic acute subdural hematomas.

The Analysis of Surgical Results of Traumatic Acute Subdural Hematoma According to Age

Objective: We aimed to analyze the surgical results of traumatic acute subdural hematoma (ASDH) in relation to the age of the patients and to report our recent experiences in treating such patients. Methods: In this retrospective study, we reviewed the case histories of 141 patients with traumatic ASDH, all of whom had undergone surgical evacuation of hematoma in course of a 5-year period. In order to identify the age-dependent clinical characteristics, the patients were divided into 3 groups according to their ages. Group A consisted of 14 patients aged 0-29 years, group B consisted of 54 patients aged 30-59 years, and group C comprised 73 patients aged over 60 years. We analyzed the clinical status, mortality, and outcomes in relation to the ages of the patients. Results: The overall male-to-female ratio was 3.7：1, and the mean age of the patients was 55.7 years (range, 1-85 years); however, the male-to-female ratio in group B was 12.5：1. The most frequent cause of trauma was vehicular accidents. The overall mortality rate was 29%, group A was 21.3%, group B was 14.8%, and group C was 24.7%. There were no significant differences in the mortality among the three groups. However, mortality rate was significantly increased among the patients aged over 70 years and less than 17 years. The surgical outcomes were significantly influenced by the age and the initial Glasgow coma scale (GCS) scores. Conclusion: Our results show the patient’s age was significantly associated with an unfavorable outcome of surgical evacuation of traumatic ASDH. Therefore, we recommend that neurosurgeons should exercise greater caution while considering surgical evacuation in the old-aged group. (J Kor Neurotraumatol Soc 2009;5:5-10)

Traumatic Acute Subdural Hematoma Extending from the Posterior Cranial Fossa to the Cerebellopontine Angle

Posterior cranial fossa subdural hematomas and extension of the subdural hematoma to the cerebellopontine angle is rarely seen and the concurrent development of acute peripheral facial palsy and the management strategy have not previously been reported in this pathology because of its rarity. We present this case to emphasize that minor head trauma may lead to a posterior cranial fossa hematoma extending to the cerebellopontine angle and cause peripheral facial palsy in patients using aspirin (acetylsalicylic acid). In addition, partial evacuation and waiting for the resorption of the hematoma may help to prevent damage to the 7th and 8th cranial nerves.

Risk factors related to hospital mortality in patients with isolated traumatic acute subdural haematoma: analysis of 308 patients undergone surgery

Acute subdural haematoma (ASDH) is a common traumatic brain injury with a relatively high mortality rate. However, few studies have examined the factors predicting the outcome of isolated traumatic ASDH. This clinical study examined the hospital mortality and analyzed the risk factors for mortality in patients treated surgically for isolated traumatic ASDH. We collected 308 consecutive patients who underwent neurosurgery for isolated traumatic ASDH between January 1999 and December 2007 and used multivariate Logistic regression analysis to evaluate the influence of 11 clinical variables on hospital mortality. The overall hospital mortality was 21.75% (67/308). Age (OR = 1.807), preoperative Glasgow Coma Score (OR = 0.316), brain herniation (OR = 2.181) and the time from trauma to decompression (OR = 1.815) were independent predictors of death, while no independent association was observed between hospital mortality and haematoma volume, midline shift, acute brain swelling or brain herniation duration, although these variables were correlated with hospital mortality in univariate analyses. This study identified the risk factors for hospital mortality in patients who underwent surgical treatment for isolated traumatic ASDH. An increased risk of death occurs in patients who are over 50 years of age and have lower preoperative Glasgow Coma Scores, the presence of brain herniation and a long interval between trauma and decompression. The findings should help clinicians determine management criteria and improve survival.

Outcome after acute traumatic subdural and epidural haematoma in Switzerland: a single-centre experience.

Acute epidural and subdural haematomas remain among the most common causes of mortality and disability resulting from traumatic brain injury. In the last three decades improvements in rescue, neuromonitoring and intensive care have led to better outcomes. The purpose of this study was to evaluate the impact of these strategies on outcome in patients treated in a single institution in Switzerland. A total of 76 consecutive patients who underwent emergency craniotomy for acute traumatic epidural and subdural haematoma at University Hospital Bern between January 2000 and December 2003 were included in this study. Thirty-seven patients presented with an epidural haematoma and 46 with a subdural haematoma. In seven patients both haematomas could be documented. The median age was 54 years (IQR 28). The median initial GCS score was 7 (IQR 6). The median time from primary injury to surgery was 3 hours (IQR 2.5 hours). The median stay in the ICU was 3 days (IQR: 3 days). The outcome was favourable (GOS 4 and 5) in 43 patients (57%). Thirteen patients (17%) remained severely or moderately disabled (GOS 3). Finally, a total of 21 patients (28%) died or remained in a persistent vegetative state (GOS 1 and 2). Mortality was 41% for acute subdural haematoma (19/46) and 3% (1/37) for patients with epidural haematoma. Only age, GCS at admission and pupil abnormalities seemed to be associated with outcome. Time to surgery was not. In patients admitted with acute traumatic epidural and subdural haematomas that are treated within a median of 3 hours after primary injury, factors such as age, initial GCS and pupil abnormalities still appear to be the most important factors correlating with outcome.

Outcome after acute traumatic subdural and epidural haematoma in Switzerland: a single-centre experience.

Acute epidural and subdural haematomas remain among the most common causes of mortality and disability resulting from traumatic brain injury. In the last three decades improvements in rescue, neuromonitoring and intensive care have led to better outcomes. The purpose of this study was to evaluate the impact of these strategies on outcome in patients treated in a single institution in Switzerland. A total of 76 consecutive patients who underwent emergency craniotomy for acute traumatic epidural and subdural haematoma at University Hospital Bern between January 2000 and December 2003 were included in this study. Thirty-seven patients presented with an epidural haematoma and 46 with a subdural haematoma. In seven patients both haematomas could be documented. The median age was 54 years (IQR 28). The median initial GCS score was 7 (IQR 6). The median time from primary injury to surgery was 3 hours (IQR 2.5 hours). The median stay in the ICU was 3 days (IQR: 3 days). The outcome was favourable (GOS 4 and 5) in 43 patients (57%). Thirteen patients (17%) remained severely or moderately disabled (GOS 3). Finally, a total of 21 patients (28%) died or remained in a persistent vegetative state (GOS 1 and 2). Mortality was 41% for acute subdural haematoma (19/46) and 3% (1/37) for patients with epidural haematoma. Only age, GCS at admission and pupil abnormalities seemed to be associated with outcome. Time to surgery was not. In patients admitted with acute traumatic epidural and subdural haematomas that are treated within a median of 3 hours after primary injury, factors such as age, initial GCS and pupil abnormalities still appear to be the most important factors correlating with outcome.

左内側後頭頭頂葉病変で発症したｐｏｓｔｓｔｒｏｋｅ ｄｅｍｅｎｔｉａの１例

We report herein a patient of poststroke dementia (PSD) following left medial occipitoparietal hemorrhage triggered by drainage of an acute traumatic subdural hematoma. The patient, an independent 73-year-old man, became dependent due to dementia. Cognitive dysfunction was characterized by moderately decreased IQ, severe memory disturbances, topographical disorientation, executive dysfunction and loss of self-awareness. Cognitive dysfunction has not advanced for 3 years. Hypo-perfusion in the whole brain, particularly in the left temporal and parietal regions, was visible on 123I-IMP SPECT images. Magnetic resonance imaging demonstrated damage to the left posterior cingulate cortex, cingulate bundle, superior parietal lobule and subcortical region of the occipital lobe. The fornix was spared. Some subcortical small spotted lesions were detected, but periventricular lucency was not prominent. Structures known to be important in memory but spared by the lesion included the thalamus and basal forebrain. Small spotted subcortical lesions were detected in bilateral hippocampi, which are also known to be important in memory, but these were probably silent lesions. This case suggested that dementia is brought on by the lesion of the left posterior cingulate bundle and retrosplenial cortex causing amnesia by disrupting the cingulate-hippocampal connection or the retrosplenial cortex itself, with the lesion of the left occipitoparietal subcortex causing frontal dysfunction by disrupting the dorsal limbic pathway and occipitofrontal fasciculus of the prefrontal circuits.

Delayed intraventricular hemorrhage with hydrocephalus following evacuation of post traumatic acute subdural hematoma

The incidence of intraventricular hemorrhage (IVH) has been increasing recently due to increased detection. The occurrence following evacuation of an acute subdural hematoma (SDH) is extremely rare. The exact mechanism of traumatic IVH in these cases has not been well documented; the erosion of the ventricular wall by adjacent hematoma has been described as the most plausible cause. The rupture of unsuspected vascular malformation following head injury has also been suggested.A case with a delayed IVH following evacuation of acute SDH is reported and the underlying pathophysiology is discussed. This entity needs to recognized and kept in mind as a potential cause of post surgical deterioration in such patients.

EVOLUTION OF BRAIN TISSUE INJURY AFTER EVACUATION OF ACUTE TRAUMATIC SUBDURAL HEMATOMAS

Acute traumatic subdural hematoma complicated by brain parenchymal injury is associated with a 60 to 90% mortality rate. Early surgical evacuation of the mass lesion is essential for a favorable outcome, but the severity of the underlying brain injury determines the outcome, even when surgery has been prompt. The purpose of this study was to analyze tissue biochemical patterns in the brain underlying an evacuated acute subdural hematoma to identify a characteristic pattern of changes that might indicate evolving brain injury. Prospectively collected data from 33 patients after surgical evacuation of acute subdural hematoma were analyzed. Both a brain tissue oxygen tension probe and an intracerebral microdialysis probe were placed in brain tissue exposed at surgery. On the basis of the postoperative clinical course, the patients were divided into three groups: patients with early intractable intracranial hypertension, patients with evolution of delayed traumatic injury (DTI), and patients with an uncomplicated course (the no-DTI group). The overall mortality rate was 46%, with 100% mortality in the intracranial hypertension group (five patients). Mortality in the DTI group was 53% compared with only 9% in the no-DTI group (P = 0.002). There were no significant differences in the initial computed tomographic scan characteristics, such as thickness of the subdural hematoma or amount of midline shift, among the three groups. Physiological variables, as well as the microdialysate measures of brain biochemistry, were markedly different in the intracranial hypertension group compared with the other groups. Differences between the other two groups were more subtle but were significant. Significantly lower values of brain tissue oxygen tension (14 +/- 8 mm Hg versus 27 +/- 14 mm Hg) and higher dialysate values of lactate and pyruvate were documented in patients who developed a delayed injury compared with patients with uncomplicated courses (4.1 +/- 2.3 mmol/L versus 1.7 +/- 0.7 mmol/L for lactate, and 104 +/- 47 micromol/L versus 73 +/- 54 micromol/L for pyruvate at 24 h after injury). Evolution of DTI in the area of brain underlying an evacuated subdural hematoma is associated with a significant increase in mortality. Postoperatively decreasing brain tissue oxygen tension and increasing dialysate concentrations of lactate and pyruvate in this area may warn of evolving brain injury and evoke further diagnostic and therapeutic activity.

Conservative management of subdural hematoma in idiopathic thrombocytopenic purpura: Report of two cases and review of literature

Intracranial hemorrhage (ICH) is the most serious complication of idiopathic thrombocytopenic purpura (ITP) and is potentially fatal. It is rare, affecting 1% or less of patients and is usually subarachnoid or intracerebral. Isolated subdural hematoma (SDH) is rare and only few cases have been reported. Two cases of acute SDH (ASDH) are reported which resolved with conservative management. One of the patients later developed intracerebral hematoma also. In ITP, contrary to traumatic ASDH, the brain parenchyma is well preserved and hence conservative management may be safe in selected patients. However, only a prospective randomized control study will give the final answer.<br>Both the patients developed the hematoma consequent to low platelet count, which was not detected earlier due to inadequate follow-up. In a developing country, where proper follow-up is often lacking these problems are likely to be more common and are probably underreported. Increased awareness is therefore important to ensure proper follow-up and early intervention.

Comparison of craniotomy and craniectomy in patients with acute subdural haematoma

Despite the increasing acceptance of craniectomy in patients with traumatic brain injury, the value of early decompressive craniectomy in patients with acute subdural haematoma is still under debate. In this retrospective study, we reviewed 180 patients with traumatic acute subdural haematoma, 111 of whom were treated with haematoma evacuation via craniotomy and 69 of whom were treated with early decompressive craniectomy. Due to the higher incidence of signs of herniation for patients in the craniectomy group, the mortality rate in this group was higher than that in the craniotomy group (53% vs. 32.3%). However, overall there was no significant difference in outcome between the two groups. Age and clinical signs of herniation were significantly associated with an unfavourable outcome, regardless of the type of surgery. Decompressive craniectomy did not seem to have a therapeutic advantage over craniotomy in traumatic acute subdural haematoma.

Intraoperative development of contralateral extradural hematoma during evacuation of traumatic acute subdural hematoma: A rare cause of malignant brain bulge during surgery

AbstractIntraoperative development of epidural hematoma (EDH) is an unusual happening. We report a 36-year-old female who developed severe brain bulge while she was being operated for a traumatic left fronto-temporal acute subdural hematoma. Immediate post-operative CT scan revealed a massive contralateral EDH, which was subsequently evacuated. When a craniotomy is performed for a traumatic hematoma, intraoperative severe brain swelling should alert the surgeon about possibility of contralateral EDH formation especially if there is contralateral skull fracture.

Rapid Resolution of Infantile Acute Subdural Hematoma: A Case Report

Subdural hematomas in infants are uncommon but usually result from non-accidental trauma or from trauma associated with motor vehicle accidents. This report describes the case of an infant with a traumatic acute subdural hematoma that resolved within 65 hours. A 23-month-old boy fell from a height of approximately 10 m. Brain computed tomography disclosed a left subdural hematoma with midline shift. The associated clots resolved spontaneously within 65 hours of the injury. Although they may mimic more clinically significant subdural hematomas, such collections of clots are likely to be located at least partly within the subarachnoid space. Their recognition may influence decisions regarding both surgical evacuation and the likelihood of non-accidental injury. Clinical and radiographic features distinguishing these "disappearing subdural hematomas" from more typical subdural hematomas are discussed.

Evolution of Brain Tissue Injury after Evacuation of Acute Traumatic Subdural Hematomas

Acute traumatic subdural hematoma complicated by brain parenchymal injury is associated with a 60 to 90% mortality rate. Early surgical evacuation of the mass lesion is essential for a favorable outcome, but the severity of the underlying brain injury determines the outcome, even when surgery has been prompt. The purpose of this study was to analyze tissue biochemical patterns in the brain underlying an evacuated acute subdural hematoma to identify a characteristic pattern of changes that might indicate evolving brain injury. Prospectively collected data from 33 patients after surgical evacuation of acute subdural hematoma were analyzed. Both a brain tissue oxygen tension probe and an intracerebral microdialysis probe were placed in brain tissue exposed at surgery. On the basis of the postoperative clinical course, the patients were divided into three groups: patients with early intractable intracranial hypertension, patients with evolution of delayed traumatic injury (DTI), and patients with an uncomplicated course (the no-DTI group). The overall mortality rate was 46%, with 100% mortality in the intracranial hypertension group (five patients). Mortality in the DTI group was 53% compared with only 9% in the no-DTI group (P = 0.002). There were no significant differences in the initial computed tomographic scan characteristics, such as thickness of the subdural hematoma or amount of midline shift, among the three groups. Physiological variables, as well as the microdialysate measures of brain biochemistry, were markedly different in the intracranial hypertension group compared with the other groups. Differences between the other two groups were more subtle but were significant. Significantly lower values of brain tissue oxygen tension (14 +/- 8 mm Hg versus 27 +/- 14 mm Hg) and higher dialysate values of lactate and pyruvate were documented in patients who developed a delayed injury compared with patients with uncomplicated courses (4.1 +/- 2.3 mmol/L versus 1.7 +/- 0.7 mmol/L for lactate, and 104 +/- 47 micromol/L versus 73 +/- 54 micromol/L for pyruvate at 24 h after injury). Evolution of DTI in the area of brain underlying an evacuated subdural hematoma is associated with a significant increase in mortality. Postoperatively decreasing brain tissue oxygen tension and increasing dialysate concentrations of lactate and pyruvate in this area may warn of evolving brain injury and evoke further diagnostic and therapeutic activity.