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Duret hemorrhages are brainstem hemorrhages that occur due to descending transtentorial herniation that results from a severe traumatic brain injury, intracranial hemorrhage, or other causes of increased intracranial pressure. These hemorrhages develop in the midline and paramedian regions of the pons and midbrain due to vascular disruption of perforating arteries. Because these blood vessels supply critical brainstem structures responsible for autonomic regulation and motor function, Duret hemorrhages are associated with a poor prognosis. Diagnosis is primarily made through neuroimaging, although some cases are only identified post-mortem. Management is directed at aggressively treating the underlying cause of the injury to prevent further neurological deterioration and improve patient outcomes. This course enhances the clinicians’ understanding of Duret hemorrhages' pathophysiology, imaging findings, and clinical significance. Participants learn to recognize the early signs of transtentorial herniation, implement evidence-based strategies for managing elevated intracranial pressure, and apply advanced neurocritical care interventions. The course highlights the importance of interprofessional collaboration among neurosurgeons, critical care specialists, and radiologists in ensuring rapid diagnosis and timely intervention. By expediting interdisciplinary communication and decision-making, clinicians improve patient monitoring, optimize treatment strategies, and enhance overall patient outcomes in severe brain injury cases. Objectives: Identify the clinical signs and imaging findings suggestive of Duret hemorrhages in patients with severe brain injury. Differentiate between Duret hemorrhages and other forms of brainstem hemorrhage based on their pathophysiology and radiologic presentation. Implement timely imaging studies to diagnose Duret hemorrhages in patients with significant brain injury and herniation syndromes. Collaborate with a multidisciplinary team to ensure optimal care for patients with Duret hemorrhages, including neurosurgeons, intensivists, and rehabilitation specialists. Access free multiple choice questions on this topic.

Duret hemorrhages are small, linear, or flame-shaped brainstem hemorrhages that occur due to transtentorial herniation involving the midbrain and upper pons. First described by the French neurologist Henri Duret, these hemorrhages result from vascular compromise due to downward displacement of the brainstem that leads to stretching and tearing of perforating arteries, particularly the paramedian branches of the basilar artery. Brainstem hemorrhages are broadly classified as primary or secondary. Primary hemorrhages arise from direct trauma, hypertension, or coagulopathy, compared to secondary hemorrhages, such as Duret hemorrhages, that occur due to descending transtentorial herniation from various etiologies.[1] Studies on brain trauma by Duret localized autonomic disturbances to the brainstem and linked them to microhemorrhages in the pons and medulla.[2] While historically considered a postmortem finding, advances in neuroimaging have enabled antemortem diagnosis of these hemorrhages, highlighting the importance of their early recognition in those who are critically ill. Given their association with devastating neurological injury, Duret hemorrhages signify an urgent need for aggressive management of intracranial hypertension and herniation syndromes. This course analyzes the pathophysiology, imaging characteristics, clinical implications, and management strategies associated with Duret hemorrhages.

Duret hemorrhages are small sites of bleeding in the brainstem due to descending transtentorial herniation, which occurs with increased intracranial pressure (ICP) and resultant intracranial compartmental brain shifts (see Image. Duret Hemorrhage, Computed Tomography Scan). The most common causes of these hemorrhages include traumatic brain injury (TBI), subdural and epidural hematoma development, intraparenchymal hemorrhage, acute diffuse cerebral edema, brain neoplasms, hyponatremia, and the rare administration of thrombolytic therapy.[3][4][5][6][7] While typically associated with increased ICP, Duret hemorrhages have also been reported in a few cases resulting from intracranial hypotension.[8][9] Duret hemorrhages develop when significant mass effect from cerebral edema, intracranial hematomas, or brain tumors causes brain tissue to shift from its normal anatomical position, resulting in uncal or transtentorial herniation. This downward displacement of the brainstem stretches and tears the penetrating arteries that supply the midbrain and pons, in particular the paramedian branches of the basilar artery. This vascular compromise leads to hemorrhagic infarction of the midline, paramedian, and ventral regions of the tegmentum of the upper pons and midbrain. Direct mechanical damage, disruption of blood flow, and sustained increase in ICP further exacerbate the brainstem injury. Duret hemorrhages represent a critical indication of severe brain injury and often indicate a poor prognosis. Their presence signifies impending brainstem compromise and is often associated with irreversible neurological damage.

The precise epidemiology of Duret hemorrhages is not widely documented because they are usually found on postmortem examination in cases of severe brain injury. These hemorrhages occur due to conditions that result in brain herniation, such as large intracranial hematomas, severe TBI, or brain tumors.[10] Since Duret hemorrhages are often a marker of irreversible brainstem injury, the condition is rarely diagnosed in patients who survive, and their true prevalence remains uncertain. The incidence of Duret hemorrhages varies significantly between neuropathological and radiological studies. Autopsy-based studies report an incidence of 30% to 60% compared to radiological studies that estimate a much lower occurrence rate of 5% to 10%.[1] This discrepancy may be explained by the fact that up to 20% of secondary brainstem hemorrhages occur at the microscopic level, which makes them undetectable on conventional imaging. Additionally, there may be a delay in developing the Duret hemorrhages, which indicates that the initial computed tomography scans may not demonstrate their presence. Risk factors associated with the development of Duret hemorrhages include arterial hypertension and advanced age, both of which may contribute to increased vascular fragility and a susceptibility to hemorrhagic infarction.[1]

Most clinicians believe that the hypothesis underlying Duret hemorrhage is related to the distortion of the pontine perforating arterial branches that extend from the relatively immobile basilar artery due to the caudal displacement of the upper brainstem, due to descending transtentorial herniation, which is coupled with an anterior-posterior elongation of the brainstem from the side-to-side compression. However, some authors have also postulated that there may be a venous origin of these hemorrhages due to obstruction of the venous return that results from a sudden increase in ICP, which results in venous thrombosis, infarction, and hemorrhage.[2][11] Duret hemorrhages represent bleeding in the midbrain and pons of the brainstem that is usually seen in cases of severe brain trauma or other conditions causing increased ICP. Here is a brief overview of the pathophysiology: Increased ICP Conditions such as TBI, brain tumors, large intracranial hematomas, or brain edema can cause a significant increase in ICP. Brain herniation The increased ICP can cause parts of the brain to shift from their normal position in a process known as herniation.[12] Specifically, uncal or transtentorial herniation can result where the medial temporal lobe is pushed against the brainstem or through the tentorial notch. Impaired blood flow This abnormal ICP and movement of the brainstem can compress or stretch the small, penetrating arteries that supply the brainstem, which prevents blood flow to those areas. Ischemic injury and hemorrhage Reduced or absent blood flow to the brainstem can cause ischemic injury to brain tissue. This vascular damage makes the blood vessels in that area more susceptible to rupture, which results in hemorrhage. Duret hemorrhages These areas of hemorrhage in the midbrain and pons are associated with the decreased blood flow to the brainstem and the resultant ischemic injury caused by the herniation process. Duret hemorrhages are usually a secondary event that occurs after a significant brain injury or in the presence of increased ICP, where they indicate severe brain damage with a poor prognosis. They are most often identified postmortem at the time of the autopsy.

In the 18th century, Henri Duret confirmed that trauma resulted in variations in cerebrospinal fluid distribution that caused changes in the ICP in the spaces where the fluid circulates, such as the cerebral aqueduct. Duret noted microhemorrhages in the brainstem and the surrounding tissue as “action of a pressure increases in the cerebrospinal fluid due to sudden accumulation, which caused a linear hemorrhage on the medulla’s thickness and around the central canal.”[1] Histopathologically, Duret hemorrhages are characterized by small, linear areas of bleeding in the midbrain and pons of the brainstem. They are usually associated with severe brain injury, such as transtentorial herniation. Upon microscopic examination, those findings may represent: Acute hemorrhage In the acute phase, red blood cells and hemorrhagic necrosis of the surrounding brain tissue may be evident. Chronic lesions If the person survives after the hemorrhage, the lesion may evolve. Over time, the hemorrhage may become organized, with macrophages infiltrating into the area to clear the dead tissue. In the later stages, gliosis, a process where glial cells proliferate to form a glial scar, may occur. Vascular disruption There may be evidence of disruption to the small, penetrating arteries of the brainstem that represent the underlying cause of the Duret hemorrhages. Associated findings Because Duret hemorrhages are usually associated with significant brain herniation, there may also be histopathological findings such as neuronal injury or necrosis in other areas of the brain that have been affected by the herniation. These histopathological features will depend on the time of the analysis and the severity of the brain injury. As Duret hemorrhages typically indicate severe brain damage and have a poor prognosis, they are often identified postmortem during an autopsy.[12]

In most cases of Duret hemorrhage, there is a prior history of head trauma, brain tumor, or another space-occupying lesion. Often, the patient may have an altered sensorium ranging from confusion to a comatose state associated with underlying transtentorial herniation and the disruption of the reticular activating system. There is often anisocoria due to the involvement of the ipsilateral third cranial nerve with contralateral motor weakness. In some cases, ipsilateral weakness can present due to the “Kernohan notch” phenomenon, where there is compression of the cerebral peduncle on the contralateral side of the brainstem against the tentorium cerebelli.[13] With downward transtentorial herniation, the patient can demonstrate progression from decorticate to decerebrate posturing with the loss of brainstem reflexes and alteration in the respiratory pattern from Cheyne-Stokes to ataxic breathing. With the upward transtentorial herniation that results following cerebral spinal fluid diversion procedures, there may be an associated Perinaud syndrome.[14][15]

The initial evaluation of the patient requires a computed tomography (CT) scan of the head to discern whether there are supratentorial and infratentorial abnormalities, such as brain tumors with vasogenic edema causing mass effect or epidural, subdural, or intraparenchymal hemorrhage. Central herniation results in complete obliteration of the perimesencephalic and perimedullary cisterns with or without small hemorrhages in the midline, paramedian, and ventral regions in the tegmentum of the upper pons and midbrain (see Image. Computed Tomography Scan of a Duret Hemorrhage). The posterior cerebral artery may occasionally be kinked at the tentorial edge, resulting in occipital lobe infarction. Required laboratory investigations include a serum sodium level, arterial blood gases, and a basic metabolic profile.

First and foremost, the airway, breathing, and circulation of the patient should be addressed. An emergent noncontrast CT scan of the head should be obtained, followed by the aggressive treatment of the intracranial hypertension if it is present on the scan. Identification of the underlying cause of the elevated ICP, with the timely management of the cause, represents the therapeutic course of action for the patient. The necessary basic labs include blood count, metabolic panel, and coagulation profile. If the clinician establishes that trauma is the cause of epidural or subdural hemorrhage leading to herniation, then the rapid surgical evacuation of the hematoma should be pursued.[16] Steps for managing increased intracranial hypertension include: Raising the head of the bed by 30 to 60 degrees. Hyperventilation may be needed to keep the PaCo2 (partial pressure of carbon dioxide) between 30 and 35 mm Hg. Osmolar therapy that includes hypertonic saline and/or mannitol therapy can help manage the pressure. ICP monitoring and keeping the ICP <20 mm Hg may be necessary. In cases of brain tumors and associated vasogenic edema, dexamethasone might help reduce the mass effect caused by the tumor. Surgical interventions (eg, decompression of mass/hematoma) may also be warranted. The clinical goal in the intensive care unit is to maintain normotension, normovolemia, normonatremia to hypernatremia, normoglycemia, and normothermia to hypothermia. Such patients are followed with serial neurological examinations and head CT scans in the intensive care unit.

The most common differential diagnosis includes primary brainstem hemorrhages, which are petechial in appearance and represent hypertensive bleeds. Radiologically, Duret hemorrhages have a linear configuration that extends in the brainstem from a ventral and dorsal location, but may be of any shape in the clinical setting of supratentorial abnormalities that cause transtentorial herniation. Primary hypertensive hemorrhages are usually larger and occur spontaneously in patients with an antecedent history of uncontrolled hypertension without supratentorial abnormalities. Petechial hemorrhages are multifocal and small in size and are seen around the dorsal midbrain in periaqueductal and tectal locations in cases with diffuse axonal injuries following TBI.[17]

The presence of Duret hemorrhages has invariably been regarded as a poor prognostic sign. However, increasing case report numbers suggest functional recovery may be possible after a Duret hemorrhage.[18] The presence of a Duret hemorrhage alone should in itself not be considered a poor prognostic indicator and should not by itself result in the decision to withdraw care.[19] Depending on the underlying cause of the transtentorial herniation, there have been a few case reports that resulted in a good prognosis in patients with severe hyponatremia, subdural hemorrhage, and TBI.[20][21][22] The direct correlation between recovery and the rapid reversibility of the underlying cause remains uncertain.

Duret hemorrhages are typically associated with severe brain injury and carry a poor prognosis due to their location in the brainstem, which contains critical autonomic and motor functions. The most significant complications arise from direct damage to the midbrain and pons, leading to devastating neurological deficits. Patients may develop loss of consciousness, coma, and ultimately, brain death due to disruption of the reticular activating system. Respiratory failure is common, as the brainstem regulates this vital autonomic function. Motor dysfunction is another major complication of Duret hemorrhage, often presenting as quadriplegia due to corticospinal tract involvement. Cranial nerve deficits may occur with abnormalities in the pupillary response, ocular movement, and ability to swallow. Patients who survive the acute phase of the injury may experience persistent neurological impairment that includes spasticity, dysphagia, and the locked-in syndrome. Additionally, the severe elevation in ICP associated with Duret hemorrhages increases the risk of secondary ischemia and further brain injury. Due to the often fatal nature of these hemorrhages, survivors typically require prolonged intensive care, mechanical ventilation, and rehabilitative support.

Deterrence of Duret hemorrhages is primarily associated with the prevention and early management of conditions that lead to increased ICP and brain herniation. Prompt recognition and treatment of intracranial hemorrhages, TBIs, brain tumors, and other causes of elevated ICP can reduce the risk of transtentorial herniation and the subsequent development of brainstem hemorrhages. Optimizing blood pressure management, particularly in hypertensive individuals, is essential because arterial hypertension has been identified as a risk factor for Duret hemorrhages. Careful monitoring and timely neurosurgical intervention in patients with expanding intracranial hematomas or severe cerebral edema can prevent secondary brainstem injury. Patient and caregiver education should emphasize the importance of seeking immediate medical attention for symptoms of increased ICP, such as severe headache, altered mental status, vomiting, and focal neurological deficits. Public awareness campaigns about TBI prevention, including the use of helmets, seat belts, and fall prevention strategies, may also play a role in reducing the incidence of severe brain injuries that can lead to Duret hemorrhages. For families of affected patients, discussions should focus on prognosis, potential complications, and the need for long-term supportive care in cases of survival.

The management of Duret hemorrhages requires a highly coordinated interprofessional approach to optimize patient outcomes due to the severe nature of brainstem injury. Clinicians, particularly neurosurgeons, intensivists, and neurologists, must promptly recognize the signs of increased intracranial pressure and implement strategies to prevent transtentorial herniation, including hyperosmolar therapy, controlled ventilation, and timely surgical decompressive intervention. Advanced clinicians and critical care nurses play a crucial role in continuous neurological monitoring, early detection of clinical deterioration, and ensuring adherence to evidence-based protocols for managing traumatic brain injury. Pharmacists contribute by optimizing medication regimens, including intracranial pressure-lowering agents, anticoagulation reversal strategies, and sedation management to prevent secondary brain insults. Effective interprofessional communication and care coordination are vital for patients who are critically ill because timely interventions can be lifesaving. Standardized protocols, such as early warning systems and structured handoff tools like SBAR (Situation, Background, Assessment, Recommendation), help ensure that critical information is accurately conveyed among all team members. Physical therapists and rehabilitation specialists also become essential for survivors by aiding in functional recovery and quality-of-life improvement. A patient-centered approach that integrates shared decision-making with family members regarding prognosis, goals of care, and potential long-term care needs enhances patient safety and overall team performance.