Consideration of the Intracranial Pressure Threshold Value for the Initiation of Traumatic Brain Injury Treatment: A Xenon CT and Perfusion CT Study

Perfusion tomography in early follow-up of acute traumatic subdural hematoma: a case series

Perfusion Computed Tomography (PCT) is an alternative tool to assess cerebral hemodynamics during trauma. As acute traumatic subdural hematomas (ASH) is a severe primary injury associated with poor outcomes, the aim of this study was to evaluate the cerebral hemodynamics in this context. Five adult patients with moderate and severe traumatic brain injury (TBI) and ASH were included. All individuals were indicated for surgical evacuation. Before and after surgery, PCT was performed and cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were evaluated. These parameters were associated with the outcome at 6 months post-trauma with the extended Glasgow Outcome Scale (GOSE). Mean age of population was 46 years (SD: 8.1). Mean post-resuscitation Glasgow coma scale (GCS) was 10 (SD: 3.4). Mean preoperative midline brain shift was 10.1 mm (SD: 1.8). Preoperative CBF and MTT were 23.9 ml/100 g/min (SD: 6.1) and 7.3 s (1.3) respectively. After surgery, CBF increase to 30.7 ml/100 g/min (SD: 5.1), and MTT decrease to 5.8s (SD:1.0), however, both changes don't achieve statistically significance (p = 0.06). Additionally, CBV increase after surgery, from 2.34 (SD: 0.67) to 2.63 ml/100 g (SD: 1.10), (p = 0.31). Spearman correlation test of postoperative and preoperative CBF ratio with outcome at 6 months was 0.94 (p = 0.054). One patient died with the highest preoperative MTT (9.97 s) and CBV (4.51 ml/100 g). CBF seems to increase after surgery, especially when evaluated together with the MTT values. It is suggested that the improvement in postoperative brain hemodynamics correlates to favorable outcome.

Placement of a Catheter into the Transverse Sinus in Monitoring Intracranial Lesions: A Technical Note

High intracranial pressure (ICP) can be induced by stroke, brain trauma, and brain tumor, and lead to cerebral injury. Monitoring the blood flow of a damaged brain is important for detecting intracranial lesions. Blood sampling is a better way to monitor changes in brain oxygen and blood flow than computed tomography perfusion and magnetic resonance imaging. This article describes how to take blood samples from the transverse sinus in a high ICP rat model. Also, it compares the blood samples from the transverse sinus and femoral artery/vein through blood gas analysis and neuronal cell staining. The findings may be of significance to the monitoring of the oxygen and blood flow of intracranial lesions.

Can the Treatment of Normal-Pressure Hydrocephalus Induce Normal-Tension Glaucoma? A Narrative Review of a Current Knowledge

Ventriculoperitoneal shunt placement is the most commonly used treatment of normal-pressure hydrocephalus (NPH). It has been hypothesized that normal-tension glaucoma (NTG) is caused by the treatment of NPH by using the shunt to reduce intracranial pressure (ICP). The aim of this study is to review the literature published regarding this hypothesis and to emphasize the need for neuro-ophthalmic follow-up for the concerned patients. The source literature was selected from the results of an online PubMed search, using the keywords "hydrocephalus glaucoma" and "normal-tension glaucoma shunt". One prospective study on adults, one prospective study on children, two retrospective studies on adults and children, two case reports, three review papers including medical hypotheses, and one prospective study on monkeys were identified. Hypothesis about the association between the treatment of NPH using the shunt to reduce ICP and the development of NTG were supported in all reviewed papers. This suggests that a safe lower limit of ICP for neurological patients, especially shunt-treated NPH patients, should be kept. Thus, we proposed to modify the paradigm of safe upper ICP threshold recommended in neurosurgery and neurology into the paradigm of safe ICP corridor applicable in neurology and ophthalmology, especially for shunt-treated hydrocephalic and glaucoma patients.

Abnormalities on Perfusion CT and Intervention for Intracranial Hypertension in Severe Traumatic Brain Injury

The role of invasive intracranial pressure (ICP) monitoring in patients with severe traumatic brain injury (STBI) remain unclear. Perfusion computed tomography (CTP) provides crucial information about the cerebral perfusion status in these patients. We hypothesised that CTP abnormalities would be associated with the severity of intracranial hypertension (ICH). To investigate this hypothesis, twenty-eight patients with STBI and ICP monitors were investigated with CTP within 48 h from admission. Treating teams were blind to these results. Patients were divided into five groups based on increasing intervention required to control ICH and were compared. Group I required no intervention above routine sedation, group II required a single first tier intervention, group III required multiple different first-tier interventions, group IV required second-tier medical therapy and group V required second-tier surgical therapy. Analysis of the results showed demographics and injury severity did not differ among groups. In group I no patients showed CTP abnormality, while patients in all other groups had abnormal CTP (p = 0.003). Severe ischaemia observed on CTP was associated with increasing intervention for ICH. This study, although limited by small sample size, suggests that CTP abnormalities are associated with the need to intervene for ICH. Larger scale assessment of our results is warranted to potentially avoid unnecessary invasive procedures in head injury patients.

Defining and Managing Pain in Stroke and Traumatic Brain Injury Research

Neurologic conditions such as stroke and traumatic brain injury are challenging conditions to study in humans. Animal models are necessary to uncover disease processes and develop novel therapies. When attempting to model these or other neurologic diseases, the accompanying anesthesia and analgesia create variables that are not part of the onset of the clinical disease in the human population but are critical components of the postinjury care both in humans and animals. To maximize model validity, researchers must consider whether the disease process or a novel therapy is being studied. Damage to the neurons of the brain or the spinal cord is not painful at the neural tissue itself, but alterations to nociceptive signaling along the pain pathway can induce chronic pain. In addition, trauma or surgery leading to the event is associated with damage to peripheral tissue. Inflammation is inextricably associated with tissue injury. Inflammation is known to evoke nociception in the periphery and drive long-term changes to neurons in the CNS. Analgesics and anesthetics alter these responses yet are required as part of humane animal care. Careful planning for effective drug administration consistent with the standard of care for humans and equivalent animal care is required.

The Use of Computed Tomography Perfusion on Admission to Predict Outcomes in Surgical and Nonsurgical Traumatic Brain Injury Patients

Introduction: The objective of this study was to investigate if data obtained from a computed tomography (CT) perfusion study on admission could correlate to outcomes for the patient, including the patient’s length of stay in the hospital and their initial and final Glasgow Coma Scale (GCS), as well as the modified Rankin Scale (mRS) on discharge. We present an initial subset of patients fulfilling the inclusion criteria: over the age of 18 with mild, moderate, or severe traumatic brain injury (TBI). Patients admitted with a diagnosis of TBI had CT perfusion studies performed within 48 hours of admission. GCS, length of stay, mRS, and discharge location were tracked, along with the patient’s course of hospitalization. Initial results and discussion on the utility of CT perfusion for predicting outcomes are presented.

Methods: Patients exhibiting mild, moderate, or severe TBI were assessed using CT perfusion within 48 hours of admission from January to July 2019 at the Arrowhead Regional Medical Center (ARMC). The neurosurgery census and patient records were assessed for progression of outcomes. Data obtained from the perfusion scans were correlated to patient outcomes to evaluate the utility of CT perfusion in predicting outcomes in surgical and nonsurgical TBI patients.

Results: Preliminary data were obtained on six patients exhibiting TBI, ranging from mild to severe. The mean GCS of our patient cohort on admission was eight, with the most common mechanism of injury found to be falls (50%) and motor vehicle accidents (50%). Cerebral blood volume (CBV) seemed to increase with Rankin value (Pearson's correlations coefficient = 0.43 but was statistically insignificant (P = 0.21)). Cerebral blood flow (CBF) was found to be correlated with CBV, and both increased with Rankin score (Pearson's correlation coefficient = 0.56) but were statistically insignificant (P = 0.27). These results suggest that with a larger sample size, CBV and CBF may be correlated to patient outcome.

Conclusion: Although more data is needed, preliminary results suggest that with larger patient populations, CT perfusion may provide information that can be correlated clinically to patient outcomes. This study shows that CBF and CBV may serve as useful indicators for prognostication of TBI patients.

Children With Severe Traumatic Brain Injury, Intracranial Pressure, Cerebral Perfusion Pressure, What Does it Mean? A Review of the Literature

Severe traumatic brain injury is a leading cause of morbidity and mortality in children. In 2003 the Brain Trauma Foundation released guidelines that have since been updated (2010) and have helped standardize and improve care. One area of care that remains controversial is whether the placement of an intracranial pressure monitor is advantageous in the management of traumatic brain injury. Another aspect of care that is widely debated is whether management after traumatic brain injury should be based on intracranial pressure-directed therapy, cerebral perfusion pressure-directed therapy, or a combination of the two. The aim of this article was to provide an overview and review the current evidence regarding these questions.

Traumatic brain injured patients: primum non nocere

PURPOSE OF REVIEW

Traumatic brain injury (TBI) remains an unfortunately common disease with potentially devastating consequences for patients and their families. However, it is important to remember that it is a spectrum of disease and thus, a one 'treatment fits all' approach is not appropriate to achieve optimal outcomes. This review aims to inform readers about recent updates in prehospital and neurocritical care management of patients with TBI.

RECENT FINDINGS

Prehospital care teams which include a physician may reduce mortality. The commonly held value of SBP more than 90 in TBI is now being challenged. There is increasing evidence that patients do better if managed in specialized neurocritical care or trauma ICU. Repeating computed tomography brain 12 h after initial scan may be of benefit. Elderly patients with TBI appear not to want an operation if it might leave them cognitively impaired.

SUMMARY

Prehospital and neuro ICU management of TBI patients can significantly improve patient outcome. However, it is important to also consider whether these patients would actually want to be treated particularly in the elderly population.

Neuroimaging of Traumatic Brain Injury

The purpose of this article is to review conventional and advanced neuroimaging techniques performed in the setting of traumatic brain injury (TBI). The primary goal for the treatment of patients with suspected TBI is to prevent secondary injury. In the setting of a moderate to severe TBI, the most appropriate initial neuroimaging examination is a noncontrast head computed tomography (CT), which can reveal life-threatening injuries and direct emergent neurosurgical intervention. We will focus much of the article on advanced neuroimaging techniques including perfusion imaging and diffusion tensor imaging and discuss their potentials and challenges. We believe that advanced neuroimaging techniques may improve the accuracy of diagnosis of TBI and improve management of TBI.

Pathophysiology and Management of Intracranial Hypertension and Tissular Brain Hypoxia After Severe Traumatic Brain Injury: An Integrative Approach

Monitoring intracranial pressure in comatose patients with severe traumatic brain injury (TBI) is considered necessary by most experts. Acute intracranial hypertension (IHT), when severe and sustained, is a life-threatening complication that demands emergency treatment. Yet, secondary anoxic-ischemic injury after brain trauma can occur in the absence of IHT. In such cases, adding other monitoring modalities can alert clinicians when the patient is in a state of energy failure. This article reviews the mechanisms, diagnosis, and treatment of IHT and brain hypoxia after TBI, emphasizing the need to develop a physiologically integrative approach to the management of these complex situations.