In Germany, the incidence of intracerebral hemorrhage ranges between 10 and 12 cases per 100.000 population. In some instances, hemorrhages can be life-threatening, but they can often be successfully treated with neurosurgery.
This article will focus on the pathogenesis of brain hemorrhage while highlighting its various causes. In this context, special attention will be paid to the different types of brain hemorrhages and their respective locations. Furthermore, it will discuss diagnosis, treatment methods, and the most suitable working utensils for this purpose.
In general, one can say that the term refers to various hemorrhages (bleedings) in and around the human encephalon. In a broader sense, it describes intracranial hemorrhages, i.e., hemorrhages occurring within the cranium. These take place around the meninges (extracerebral) or inside the encephalon (intracerebral).
However, strictly speaking, only intracerebral hemorrhages (within the parenchyma) are referred to as cerebral hemorrhages. This primarily affects people with chronic hypertension and acute high blood pressure crises, which may cause sudden intracranial bleeding.
In addition to hypertension as a cause, other factors and diseases can increase the risk of intracerebral or extracerebral hemorrhage. These include:
- Brain and vascular tumors
- Vascular malformations such as aneurysms or angiomas
- Blood clotting disorders
- Cerebral venous sinus thrombosis
- Drug abuse
- Post-surgical complications
Other aspects that can have an influence include weakness in general health, age, a genetic disposition or an unhealthy lifestyle, taking drugs for example. In the case of the latter, smoking and excessive alcohol consumption are particularly worth mentioning.
Cerebral Hemorrhage: What Causes a Brain Bleed?
But what causes a brain bleed? Generally, and regardless of its locality, one can say that blood vessels are injured or burst inside the cranium, causing intracranial bleeding. Thus, damaging the tissue of the encephalon due to the pressure of the escaping blood. This can result in neurological malfunctions similar to these, occurring during a stroke (apoplexy).
A brief digression: In contrast to brain hemorrhage, neurological impairments during a stroke are caused by insufficient blood flow (ischemia) to the brain tissue, which is damaged as a result. The most common cause is a stenosis (narrowing) of the large blood vessels and arteries supplying the brain. Risk factors for apoplexies are diabetes mellitus, hypertension, nicotine, hypercholesterolemia, coronary heart disease (CHD), and cardiac arrhythmias.
Since the encephalon needs 20 percent of the cardiac output for its perfusion, a deficient blood supply is tolerable only for a short amount of time and is reversible only in the first few hours. Thus, an ischemic stroke is always an emergency that must be treated in a specialized neurological department. Treatment aims to quickly restore the blood supply and maintain the function of the affected areas of the brain.
Skull Fracture: A Possible Cause of Brain Hemorrhage
Trauma can cause brain bleeding: An accident or a fall that causes a concussion or even a skull fracture can result in a traumatic brain injury (TBI). The consequence can be bleedings in different areas. About one-fourth of TBI patients are children under the age of 15. However, not all of them suffer intracranial bleeding. In most cases, there is only a mild TBI in the form of a concussion, for example.
In this case, symptoms such as a headache, nausea, or memory lapses may occur, but there are no visible injuries to the encephalon. Although children often fall or hit their heads, they are not among the primary risk group for cranial bone fracture-related brain hemorrhage.
The reason: they don’t fall as far as adults, which is a clear advantage. But still, a fall from the couch, changing table, or climbing frame is enough to lead to a TBI. More likely to suffer harmful falls are alcoholics or elders who are unsteady in their movements and people who play certain sports professionally.
There are guidelines for this in the U.S. that regulate the playing of football or rugby concerning TBI and prohibit header training in adolescence. Particularly for those already in danger of falling, taking blood-thinning medications is an additional risk factor for suffering a brain hemorrhage.
However, intracranial bleedings also occur without external influences. For example, they can be caused by arterial bulges, so-called aneurysms, which can suddenly burst. A hemorrhage resulting from an aneurysm usually occurs as a subarachnoid hemorrhage. It represents a life-threatening clinical condition and must be treated in the hospital immediately.
The classic symptom is a thunderclap headache. In addition, nausea, neck stiffness (meningism), a feeling of numbness, or unconsciousness can also be experienced by affected individuals.
Are There Different Types of Brain Bleeds?
Four different types of brain bleeds can be distinguished, depending on the area of occurrence.
- Intracerebral: it occurs directly in the encephalon. Various neurological deficits may occur depending on the locality of the bleeding, including immediate unconsciousness in the case of torrential bleeding. Deep-seated, non-space-occupying bleedings, such as basal ganglia hemorrhages, are usually not treated surgically.
- Subdural: is the most common intracranial bleeding. The hematoma occurs acutely due to an accident below the meninges (subdural hemorrhage), requiring direct surgical relief. It is prognostically quite unfavorable if the space-occupying effect is severe. Chronic subdural bleedings often affect older people: When a minor trauma has occurred several weeks prior, bridging veins may have ruptured, resulting in a slowly developing hemorrhage. In most cases, cannulation can release the diluted blood with a satisfactory clinical outcome.
- Subarachnoid hemorrhage: it appears between the sheets of the meninges, usually caused by a ruptured aneurysm. It represents a life-threatening condition that requires prompt diagnosis and care. A complex intensive medical therapy follows to avoid further complications, particularly vasospasm-related cerebral infarctions.
- Epidural: The bleeding occurs between the meninges and the cranial bones and is most often caused by trauma, commonly associated with a cranial bone fracture. Typically, patients are initially still awake and then rapidly become drowsy. In this case, prompt surgical relief is absolutely crucial.
Brain Bleed Symptoms: From Diagnosis to Surgery.
Those affected do not necessarily recognize brain bleed symptoms, even if it is a medical emergency. Seemingly harmless symptoms such as nausea, a headache, or a fine motor disorder may very well be the cause of a brain hemorrhage.
However, also severe symptoms such as seizures can be an indication. The consequences can be life-threatening without an appropriate assessment (diagnosis) and subsequent surgery. Above all, computer tomography (CT) provides rapid elucidation when making the initial diagnosis and represents the gold standard.
The bleeding can, thus, be easily demarcated from the brain tissue, and the process only takes a few minutes. If there is evidence of a vascular malformation based on the blood flow, vascular imaging must be performed. This can be done as a CT angiography by applying a contrast agent.
If an aneurysm is suspected, digital subtraction angiography (DSA) remains the gold standard. During this procedure, one inserts a catheter through the groin to the cerebral vessels. After adding a contrast agent, one is then able to visualize the cerebral vessels and aneurysms in different layers.
Magnetic resonance imaging (MRI) is usually not necessary in an emergency and tends to be too time-consuming. However, if a hemorrhaged tumor is suspected, it can provide additional diagnostic insight. Depending on the location and extent of the bleeding, a surgical procedure may need to be performed immediately after diagnosis to avoid wasting time.
Further diagnosis takes priority in cases of subarachnoid hemorrhages with suspected aneurysms. Many hemorrhages do not require a surgical operation but optimal conservative treatment and ICU monitoring.
The Choice of the Right Tools.
In addition to the expertise of the surgeons, the choice of optimal tools is also crucial when surgery is necessary to achieve the best results in the subsequent removal of the hemorrhage.
The head is secured in a Mayfield clamp, preventing it from moving while being handled during the surgical procedure. When the patient is sedated, a total of three metal spikes are drilled into the top of the cranium from both sides. The mandrels are connected to a mount attached to the operating table, thus, ensuring that the head is securely held in place.
With this procedure, the turned head can also be fixated laterally, which may be necessary depending on the location of the hemorrhage. The patient must turn their head to one side to eliminate an aneurysm known as clipping to achieve an accurate angle of sight for the surgent. Corrective work on the fine vessels is equally only possible by fixing the head.
egardless of the compartment in which one locates the bleeding, the skullcap must be opened first. This is done by drilling a round hole into the bone, using a trephine like the evoDrill. Underneath lies the meninges, also known as the dura. In a so-called subdural hematoma, blood collects precisely under these meninges.
When the bleeding is older, i.e., developed under the meninges over weeks after a possible minor trauma, one refers to it as a chronic subdural hematoma. In this case, the blood components are no longer solid but liquefied. The dura can thus be incised via the burr hole, and the old, liquefied blood is flushed out. If necessary, a drain can be inserted for a few days to release further fluid.
All fresh hemorrhages consist of solid blood clots. To remove them, the surgent must saw-out a bone flap out of the skull. For this, a hole is first drilled into the cranium, sawing out the bone flap with a so-called craniotome. Usually, the bone flap is then reinserted and fixed with mini plates and screws.
These are available in different shapes and sizes, ensuring the best solution for each patient. If severe swelling is involved, the bone flap is not reinserted immediately but rather cryopreserved. The flap can be reimplanted when the swelling has subsided after a few weeks.
Alternatively, an artificial replacement in the shape of the patient’s cranium, like the evoShape, can be used. Such implants for reconstruction are also used when cranial bone fractures with multiple fragments are present or when an infection is an issue.
One achieves an excellent cosmetic outcome when the implants are custom-made based on a planning CT and thus cover the pre-existing defect perfectly.
Evonos’ single-use cranial perforator is available in different diameters depending on the indication. It enables precise perforation of the cranial bone with less force, even around critical structures such as large blood vessels.
Especially in emergencies, a fast and safe opening of the cranium is crucial to provide rapid relief. In this context, saving force and energy during the initial steps are necessary. This is especially true for more complex operations, such as aneurysm repair.
For surgeons, good equipment means safer, more comfortable, and faster work with far better results – from which, above all, patients also benefit.