Intracranial hemorrhage (ICH), also known as intracranial bleed, is

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

within the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

. Subtypes are intracerebral bleeds (

intraventricular bleed Intraventricular hemorrhage (IVH), also known as intraventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from phys ...

s and intraparenchymal bleeds),

subarachnoid bleed Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consc ...

s, epidural bleeds, and

subdural bleed A subdural hematoma (SDH) is a type of bleeding in which a collection of blood—usually but not always associated with a traumatic brain injury—gathers between the inner layer of the dura mater and the arachnoid mater of the meninges surround ...

s. More often than not it ends in a lethal outcome. Intracerebral bleeding affects 2.5 per 10,000 people each year.

Signs and symptoms

Intracranial hemorrhage is a serious

medical emergency A medical emergency is an acute injury or illness that poses an immediate risk to a person's life or long-term health, sometimes referred to as a situation risking "life or limb". These emergencies may require assistance from another, qualified ...

because the buildup of blood within the skull can lead to increases in

intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adult. ...

, which can crush delicate brain tissue or limit its blood supply. Severe increases in intracranial pressure (ICP) can cause

brain herniation Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrat ...

, in which parts of the brain are squeezed past structures in the skull.

Causes

Trauma is the most common cause of intracranial hemorrhage. It can cause epidural hemorrhage, subdural hemorrhage, and subarachnoid hemorrhage. Other condition such as hemorrhagic parenchymal contusion and cerebral microhemorrhages can also be caused by trauma. Non-traumatic causes of hemorrhage includes: hypertension, cerebral amyloid angiopathy, hemorrhagic conversion of ischemic infarction, cerebral aneurysms, dural arteriovenous fistulae, cerebral venous sinus thrombosis, cerebral vasculitis and mycotic aneurysm. More than half of all cases of intracranial hemorrhage are the result of hypertension.

Diagnosis

CT scan (

computed tomography A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

) of the brain (without any

iodinated contrast Iodinated contrast is a form of intravenous radiocontrast agent containing iodine, which enhances the visibility of vascular structures and organs during radiographic procedures. Some pathologies, such as cancer, have particularly improved visib ...

), is the initial imaging choice because of its high speed, good accessibility in hospitals, high sensitivity in detecting brain injuries or brain diseases, thus helping to

triage In medicine, triage () is a practice invoked when acute care cannot be provided for lack of resources. The process rations care towards those who are most in need of immediate care, and who benefit most from it. More generally it refers to pri ...

patients in emergency department in a timely manner and urgent neurosurgical intervention can be administered. Examples of brain diseases that require urgent intervention are: large volume hemorrhage,

, and cerebral infarction. Other advantages of CT over MRI scan are ability to detect bony fractures, vascular injury, and

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

(CSF) leak. It also does not need to screen for MRI safety of implants/foreign body especially for penetrating or blast injuries. However, MRI has higher sensitivity than CT scan for the detection of epidural hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, nonhemorrhagic cortical contusions, hemorrhagic parenchymal contusions, brainstem injuries, and white matter axonal injuries. If CT scan shows normal findings, but the subject has persistent neurological symptoms, MRI is also indicated. However, MRI safety concerns on metallic foreign bodies, limited availability, longer imaging time, high sensitivity to motion, and higher cost limits the usefulness of MRI. Swirl sign on CT scan (areas of low densities with surrounding areas of high densities) is indicative of active intracranial bleeding, high chance of death within one month, and poor subject's function in three months if the subject is still alive. When ICP is increased the heart rate may be decreased.

Traumatic

Types of intracranial hemorrhage are roughly grouped into intra-axial and extra-axial. Intra-axial hemorrhage is bleeding within the brain itself, or

cerebral hemorrhage Intracerebral hemorrhage (ICH), also known as cerebral bleed, intraparenchymal bleed, and hemorrhagic stroke, or haemorrhagic stroke, is a sudden bleeding into the tissues of the brain, into its ventricles, or into both. It is one kind of bleed ...

. This category includes intraparenchymal hemorrhage, or bleeding within the brain tissue, and intraventricular hemorrhage, bleeding within the brain's ventricles (particularly of premature infants). Intra-axial hemorrhages are more dangerous and harder to treat than extra-axial bleeds. Hemorrhagic parenchymal contusions and cerebral microhemorrhages are examples of traumatic intra-axial bleeds. Extra-axial hemorrhage, bleeding that occurs within the skull but outside of the brain tissue, falls into three subtypes: epidural hematoma, subdural hematoma, and subarachnoid hemorrhage.

Hemorrhagic parenchymal contusion

This condition most commonly occurred in those with significant head movement or head impact. It is caused by injuries of small arterial or venous vessels, causing hemorrhage within the brain parenchyma, and give rise to hyperdense lesion on CT scan. MRI is more sensitive than CT scan in detecting such small hemorrhagic contusions, with the use of gradient echo sequence. Contusions are more commonly seen in the brain parenchyma near base of the skull such as inferior frontal lobes and temporal lobes as a result of Coup contrecoup injury. Those with parenchymal contusion would require frequent follow-up imaging because such contusions may grow large enough to become hemorrhage and exerts significant mass effect on the brain. Cerebral microhemorrhages is a smaller form of hemorrhagic parenchymal contusion and are typically found in

white matter White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distributi ...

. Such microhemorrhages are difficult to be detected on CT scan, but easily detected on gradient echo and susceptibility weighted imaging on MRI scan as hypointense susceptibility blooming. Such microhemorrhages are frequently associated with

diffuse axonal injury Diffuse axonal injury (DAI) is a brain injury in which scattered lesions occur over a widespread area in white matter tracts as well as grey matter. DAI is one of the most common and devastating types of traumatic brain injury and is a major cause ...

and located near the

grey Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be compos ...

-white matter junction.

Epidural hemorrhage

Epidural hemorrhage Epidural hematoma is when bleeding occurs between the tough outer membrane covering the brain (dura mater) and the skull. Often there is loss of consciousness following a head injury, a brief regaining of consciousness, and then loss of consciou ...

(extradural hemorrhage, EDH) which occur between the

dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous syste ...

(the outermost

meningeal In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...

layer) and the skull, is caused by trauma. It does not cross the suture lines of the skull because the superifical dural layer is attached tightly to the skull along the suture lines. Unless rarely, fracture involves the suture lines (more common in children), then epidural hematoma may cross the suture lines. As the blood accumulated in the epidural space is confined within suture lines, accumulation of additional blood will cause bulging in this space, and thus resulting in a typical "biconvex" appearance on CT scans. EDH can be due to arterial or venous rupture depending on the locations. Arterial injuries results in more rapidly growing hematoma when compared to venous injuries. At the

pterion The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join. It is located on the side of the skull, just behind the temple. Structure The pterion is located in the temporal fossa, approximately 2.6 cm b ...

region, middle meningeal artery is most commonly affected. When fracture is crossing areas where

dural venous sinuses The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial sinuses) are venous channels found between the endosteal and meningeal layers of dura mater in the brain. They receive blood from the cerebral veins, receive cerebr ...

resides, venous hemorrhage can occur such as

falx cerebri The falx cerebri (also known as the cerebral falx) is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure between the cerebral hemispheres of the human brain,Saladin K. "Anatomy & Physiology: The Un ...

tentorium cerebelli The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes. Structure The cerebellar tentorium is an arche ...

, and vertex (where superior sagittal sinus resides). Anterior temporal EDH is usually caused by sphenoparietal sinus. Such EDH is limited and does not require surgery because its extension is confined within sphenosquamosal suture and

orbital fissure Orbital fissure may refer to: * Inferior orbital fissure * Superior orbital fissure The superior orbital fissure is a foramen or cleft of the skull between the lesser and greater wings of the sphenoid bone. It gives passage to multiple structu ...

. In 20 to 50% of epidural hemorrhage cases, there is a lucid interval where a person regained consciousness after being knocked unconscious and then followed by deterioration of consciousness after that. When the epidural hematoma is large enough, it will cause mass effect on contralateral brain which lead to midline, subfalcine (below the

), and trans-tentorial (crossing

) herniations. This phenomenon can cause the subject to lose consciousness and eventually death. Therefore, large EDH requires emergent surgical clot evacuation. Embolisation of middle meningeal artery is performed if the hemorrhage is medium or small.

Subdural hemorrhage

Subdural hemorrhage (SDH) results from tearing of the bridging veins in the subdural space between the

dura Dura may also refer to: Đura such as, for example, Đura Bajalović Geography * Dura language, a critically endangered language of Nepal * Dura, Africa, an ancient city and former bishopric, now a Catholic titular see * Dura-Europos, an ancient c ...

and arachnoid mater. It can cross the suture lines, but not across dural reflections such as falx cerebri or tentorium cerebelli. Therefore, subdural hematoma always limited to one side of the brain. Density of SDH reduces as it progresses from acute to chronic forms. However, areas with low density may not represent chronic SDH entirely as unclotted blood products that are due to active bleed can also give low density appearance on CT scans especially those with

coagulopathy Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding (bleeding diathesis), which may occur sp ...

. Those with SDH that have same density with brain parenchyma may represent acute bleed such as those with

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, ...

, arachnoid tear, and the mixing of hemorrhage and CSF. SDH usually have high or mixed densities during first two days of trauma, followed by isodensity at 11 days after trauma, and hypodensity after 14 days of trauma. Membranes with

granulation tissue Granulation tissue is new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size ...

can rupture within SDH, and give high density appearance on CT scan. Over a prolonged period of time, calcifications can form. SDH can be treated with burr hole drainage, craniotomy or port system placement for blood clot evacuation, or middle meningeal artery embolisation. Subdural hematoma maybe less acute than epidural hematoma due to slower blood accumulation, but it still has the potential to cause brain herniation that may require surgical evacuation. Clinical features depend on the site of injury and severity of injury. Patients may have a history of loss of consciousness but they recover and do not relapse. Clinical onset occurs over hours. Complications include focal neurologic deficits depending on the site of hematoma and brain injury, increased intracranial pressure leading to herniation of brain and

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

due to reduced blood supply and seizures.

Subarachnoid hemorrhage

A ''subarachnoid hemorrhage'' (SAH) is

into the

subarachnoid space In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is locate ...

—the area between the arachnoid membrane and the

pia mater Pia mater ( or ),Entry "pia mater"
in
brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...

. Trauma can also cause SAH when the arteries and veins coursing through the subarachnoid space are ruptured. It is usually located at the cerebral sulci near the vertex of the head and spare the

basal cisterns The interpeduncular cistern of Sweeney is the subarachnoid cistern that encloses the cerebral peduncles and the structures contained in the interpeduncular fossa and contains the arterial circle of Willis as well as the oculomotor nerve The ...

on CT scan. Severe trauma can cause SAH in all parts of the brain. When the SAH volume is large, rarely it can cause cerebral infarction a few days after trauma due to arterial vasospasm. Although CT scan is performed more often than MRI to detect SAH, MRI is more sensitive than CT in this aspect. SAH shows hyperintense signal of Fluid-attenuated inversion recovery (FLAIR) sequence and blooming artifact on susceptibility weighted imaging (SWI).

Computed tomography angiography Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used for angiography—the visualization of arteries and veins—throughout the human body. Using contrast injected into the blood vessels, ...

(CT angiography) or Magnetic resonance angiography (MR angiography) should be done if fracture involves the carotid canal, because in such cases, posttraumatic vasospasm can occur, thus cutting blood supply to the brain. Besides, intracranial hemorrhage that are atypical for trauma should also be investigated further with CT or MR angiography to look for other causes of intracranial bleeds apart from trauma causes. Such atypical patterns includes: isolated SAH in the

, isolated large-volume SAH in the Sylvian fissure, and isolated SAH in the anterior interhemispheric fissure. These cases warrants investigations to look for aneurysms that can cause such bleeding.

Non-traumatic

Hypertensive bleed

Intracranial bleed in hypertensive subjects usually occurs at 50 to 60 years of life with 30 to 50% chance of death. Such hemorrhages are typically located in the

basal ganglia The basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an extern ...

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cere ...

, or occipital lobes. Other location such as bleed within the cerebral cortex and intracranial bleed in people younger than 50 years should prompt further investigations on other causes of bleed such as brain tumour or

cerebral arteriovenous malformation A cerebral arteriovenous malformation (cerebral AVM, CAVM, cAVM) is an abnormal connection between the arteries and veins in the brain—specifically, an arteriovenous malformation in the cerebrum. Signs and symptoms The most frequently observe ...

. The bleed can be very small without any significant effect on surrounding brain or large hemorrhage that exerts mass effecct on adjacent brain. Follow up CT scan is recommended. Those with extension of bleed into the

ventricular system The ventricular system is a set of four interconnected cavities known as cerebral ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF). The ventricular system is c ...

, expansion of bleeding, or increasing cerebral oedema on CT scan gives poorer prognosis. CT angiography (CTA) of brain can be performed to investigate the source of bleeding. An image during the delayed phase of the CTA may be taken to look for pooling of contrast that signifies active bleeding (known as "Spot sign"). Presence of "Spot sign" signifies poor clinical outcome for the subject.

Cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is the deposition of

Amyloid beta Amyloid beta (Aβ or Abeta) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid precursor protein (APP), which i ...

peptide protein within the brain. Accumulation of such peptide proteins within the walls of the arteries can cause weakening of the walls and causes microhemorrhages, SAH within the cerebral sulci or large cerebral intraparenchymal bleed. SAH in CAA can be differentiated from

vasculitis Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily caused ...

by its presentations. SAH in CAA usually occurs in those who age more than 60 years, temporary motor and sensory deficits, and intracranial bleed in white matter adjacent to cerebral cortex. Basal ganglia, posterior fossa, and brainstem are spared. Boston criteria is used to determine the likelihood of a cerebral hemorrhage due to CAA. Definitive diagnosis of CAA is by performing

brain biopsy Brain biopsy is the removal of a small piece of brain tissue for the diagnosis of abnormalities of the brain. It is used to diagnose tumors, infection, inflammation, and other brain disorders. By examining the tissue sample under a microscope, the ...

CT scan may show hyperdense intra-axial hemorrhage in the subcortical region. Diffuse white matter hypodensities in both cerebral hemispheres may represents microangiopathic changes. On MRI these lesions will be presented as blooming artifact on gradient echo and susceptibility weighted imaging.

Hemorrhagic conversion of ischemic infarction

43% of those with infarcted brain tissue will develop hemorrhagic conversion. Risk of hemorrhagic is further increased with recanalisation of veins or arteries. Several types of hemorrhages can occur such as petechial hemorrhages around the infarcted margin (HI1), confluent petechial hemorrhages within the infarcted tissue (HI2), hematoma occupying less than 30% of the infarcted tissue (PH1), hematoma involving greater than 30% of infarcted tissue with small mass effect (PH2), and hematoma involving greater than 30% of the infarcted tissue with significant mass effect. However, only PH2 is clinically significant. Those who has infarction should be monitored frequently with CT brains to access hemorrhagic conversions or worsening vasogenic oedema that may require neurosurgical decompression. Dual energy CT scan maybe useful to differentiate the high densities caused by reperfusion hemorrhage (bleeding after endovascular stroke treatment) and high density due to iodinated contrast administered during

cerebral angiography Cerebral angiography is a form of angiography which provides images of blood vessels in and around the brain, thereby allowing detection of abnormalities such as arteriovenous malformations and aneurysms. It was pioneered in 1927 by the Portugue ...

Cerebral aneurysm

Besides from head injury, it may occur spontaneously, usually from a ruptured

cerebral aneurysm An intracranial aneurysm, also known as a brain aneurysm, is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel. Aneurysms in the posterior circu ...

(focal outpouchings with weakened walls on the arteries on the brain surface that are prone to rupture).

Symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...

s of SAH include a severe

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a resul ...

with a rapid onset (

thunderclap headache A thunderclap headache is a headache that is severe and has a sudden onset. It is defined as a severe headache that takes seconds to minutes to reach maximum intensity. Although approximately 75% are attributed to "primary" headaches—headache d ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

, confusion or a lowered level of consciousness, and sometimes

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with l ...

s. CT scan has 100% sensitivity of detecting SAH at 6 to 24 hours after symptoms onset. The

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...

is generally confirmed with a

CT scan A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

of the head. If CT scan is normal but SAH is still strongly suspected,

lumbar puncture Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to ...

can be done at six to twelfth hours after the onset of headache. This is determine the presence of blood within the

(CSF). Those with SAH will have blood and

bilirubin Bilirubin (BR) (Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the ...

within CSF because of degradation

red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

. Meanwhile, those who has blood within CSF due to traumatic lumbar puncture will not have bilirubin within CSF. SAH is generally located within

, extends diffusely to all

subarachnoid spaces In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in ...

( cerebral sulci) or into the

, or brain parenchyma. Modified Fisher scale is used to describe the volume and distribution of SAH, just predicting the probability of cerebral artery vasospasm after SAH. Treatment is by prompt

neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty concerned with the surgical treatment of disorders which affect any portion of the nervous system including the brain, spinal cord and ...

or radiologically guided interventions with medications and other treatments to help prevent recurrence of the bleeding and complications. Since the 1990s, many aneurysms are treated by a minimal invasive procedure known as endovascular coiling, which is carried out by instrumentation through large blood vessels. However, this procedure has higher recurrence rates than the more invasive craniotomy with clipping.

Cerebral ateriovenous malformation

Cerebral ateriovenous malformation (Cerebral AVM) is characterised by abnormal shunting between cerebral arteries and veins without going through capillaries. Instead the blood goes through a collection of small vessels from arteries to veins. These collection of abnormal small vessels is termed as "nidus". This condition happens in 0.1% of the population has a risk of 2 to 4% per year for intracranial bleeding. Once ruptured, it results in intraparenchymal hemorrhage, intraventricular hemorrhage and SAH. Rupture of cerebral AVM often occurs in young people and children. Cerebral AVM can be diagnosed by

computed tomography angiography Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used for angiography—the visualization of arteries and veins—throughout the human body. Using contrast injected into the blood vessels, ...

(CTA) brain, magnetic resonance angiography (MRA) brain, or digital subtraction angiography (DSA). DSA is important to determine whether there is nidal or perinidal aneurysm.

Dural arteriovenous fistulae

Dural arteriovenous fistulae (DAVF) is the direct connection between dural or cerebral arteries with dural venous sinuses or cortical veins. It accounts for 10 to 15% of intracranial arteriovenous shunts. DAVF lacks a nidus. Signs and symptoms of DAVF are: headache,

tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...

, neurological deficits involving

cranial nerves Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and ...

, and increased intracranial pressure. DAVF once ruptured, will produce intraparenchymal hemorrhage or SAH. Increase in number of vessels near dural venous sinuses as seen on CTA is suggestive of DVAF. 4DCT may increase the sensitivity of detecting DAVF. In MRI scans, susceptibility weighted imaging (SWI) and arterial spin labelling sequences (labelling protons in blood without the use of contrast media to determine blood flow) are useful in evaluating DAVF. The patterns of draining veins from the fistula determines the risk of DAVF rupture. Increased pressure within the dural venous sinuses causes backpressure into the cortical veins, thus making cortical veins more prone to rupture. The risk of hemorrhage is graded by Cognard and Borden grading systems. These grading systems are based upon the DSA.

Cortical venous/cerebral venous sinus thrombosis

Dural venous sinus thrombosis (DVST) and cortical venous thrombosis (CVT) commonly presents with headache, increased intracranial pressure, or seizures. DVST is more common than CVT. DVST are frequently caused by infections in the skull base, dehydration, thrombophilia,

meningioma Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing ...

, and other dural tumours. On CT scans, brain parenchymal hemorrhage that does not confined to specific arterial territory along with hyperdense appearance on dural venous sinuses raises the suspicion of DVST. Further evaluation with CT venography, MR venography, and post gadolinium MRI provides accurate diagnosis of venous thrombosis and follow-up after treatment. These studies demonstrate thrombus as filling defect or lack of signal.

Vasculitis/vasculopathy

Those with vasculitis may be presented with headache, behavioural changes, neurological deficits, or intracranial bleeding. Sulcal SAH is the most common form of intracranial bleed caused by vasculitis. On CT scans, sulcal SAH is seen as hyperdensity within the cerebral sulcus, while on MRI, it is seen as hyperintensity on FLAIR sequence, and hypointensity on GRE/SWI sequence. DSA is important in making the diagnosis of vasculitis or vasculopathy.

Mycotic aneurysm

It is arterial outpouchings arise from distal cerebral arteries. These are

pseudoaneurysm A pseudoaneurysm, also known as a false aneurysm, is a locally contained hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or sur ...

, caused by thrombus clogging the distal arteries, which results in inflammation and small tears at the site of occlusion. These inflammation and thrombis can caused by

infective endocarditis Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Signs and symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. Complication ...

, artificial heart valve or other heart problems. Similar to vasculitis, rupture of mycotic aneurysm also causes SAH in cerebral sulci, mostly located in the vertex. If mycotic aneurysm is located more proximally, it will produce diffuse SAH pattern. CTA or MRA would produce focal outpouching or increase in diameter of the vessel. Meanwhile, GRE/SWI MRI sequence would produce focal hypointensity. Small mycotic aneurysms are difficult to be seen on CT or MRI. Thus, DSA is useful in identifying these lesions.

Management

For those who is already on blood thinners such as

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat in ...

clopidogrel Clopidogrel — sold under the brand name Plavix, among others — is an antiplatelet medication used to reduce the risk of heart disease and stroke in those at high risk. It is also used together with aspirin in heart attacks and following ...

for prevention of

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ...

or stroke, traumatic intracranial hemorrhage should prompt the use of platelet function assays (

PFA-100 The PFA-100 (Platelet Function Assay or Platelet Function Analyser120 seconds) may indicate the following; * Anemia (hematocrit <0.28) * Thrombocytopenia (platelet count < 100 x 10/L) * A significant platelet function defect other than aspirin Once ...

) to assess the effect of these antiplalelet agents. After that, plateletpheresis can be started to increase the aggregation of platelets, thus stopping the intracranial bleed. In those with impaired kidney functions, desmopressin or

cryoprecipitate Cryoprecipitate, also called cryo for short, is a frozen blood product prepared from blood plasma. To create cryoprecipitate, fresh frozen plasma thawed to 1–6 °C is then centrifuged and the precipitate is collected. The precipitate is re ...

can be used instead. From limited observational data, it may be relatively safe to restart

blood thinners Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where t ...

after an ICH as it is asscoated with reduced thromboembolic complications with similar risk of recurrent hemorrhage when compared to those did not start blood thinners after an ICH.

Comparison

References

External links

{{Authority control Neurotrauma Stroke