Neurology-Online

What are the causes of a cerebral hemorrhage?

introduction

With a cerebral hemorrhage (intracranial hemorrhage) there is bleeding within the skull, causing a intracerebral Bleeding (bleeding into the brain tissue) from a Subarachnoid hemorrhage (Bleeding between the middle and inner layer of the meninges).

In both cases, the hemorrhage leads to compression of the surrounding brain areas, an insufficient supply of blood to the brain tissue supplied by the affected vessel and an increase in pressure within the skull. There are many reasons for a cerebral hemorrhage. In addition to trauma (fall, blow), vascular diseases, tumors and coagulation disorders can also trigger cerebral hemorrhage.

causes

There are numerous causes of a cerebral hemorrhage. A distinction can be made between traumatic and non-traumatic causes:

Traumatic brain trauma (fall, blow, traffic accident)
Aneurysms (protuberance of the vessel walls)
Hypertensive microangiopathy (damage to the vascular wall caused by high blood pressure)
(Brain) tumors
Coagulation disorders (with an increased tendency to bleed)
Amyloid angiopathy (disease with deposition of proteins in the vessels of the brain, which causes stenoses - constrictions of the vessels - and aneurysms - protuberances of the vessel wall)
Congenital vascular malformations (e.g. AV malformation with short-circuit connections between arteries and veins in the brain)
Vasculitis (chronic inflammation of the blood vessel walls)

Fall / trauma / blow

Traumatic brain injuries (TBI) are a common cause of cerebral hemorrhage. In the context of severe falls or blows to the skull, the cerebral vessels rupture and consequently bleeding into the brain tissue.

A distinction is made between primary and secondary brain damage in traumatic brain injuries. First of all, the force applied during a fall or blow results in a fracture of the skull and compression or damage to the underlying brain tissue (primary brain damage). In addition, a rupture of the superficial cerebral vessels often causes bleeding into the tissue.

The secondary brain damage describes the complications of a traumatic brain injury that occur in the further course. These can occur immediately after the trauma or after a few days to weeks. Secondary brain damage includes Hematomas (Blood accumulation), Brain edema (Swelling of the tissue due to a build-up of fluid), brain swelling, Hypoxia (Lack of oxygen) and Hypotension (low blood pressure).

The increase in pressure caused by hematomas, cerebral edema or swelling of the brain, in particular, poses the risk of the brain stem and midbrain being trapped in the bony skull with the loss of vital functions (e.g. due to compression of the respiratory center).

Read more on the topic: Increased intracranial pressure - signs, causes, and treatment

High blood pressure

Another common cause of cerebral hemorrhage is vascular damage caused by chronic high blood pressure (hypertensive microangiopathy). The permanently increased blood pressure values lead to an arteriosclerotic remodeling with a hardening of the vessel walls (increase in wall thickness). This process is exacerbated by other risk factors (such as diabetes mellitus, smoking or increased LDL cholesterol levels).

As a result, the vessels lose the ability to regulate the vessel diameter depending on the blood pressure value. In the final stage of this process, the calcified vessel walls become brittle, which leads to the development of Aneurysms (Protrusion of the vessel wall) or blood clots is favored. Due to the weakened wall stability, there is at the same time an increased risk of rupture of the vessel wall. The small vessels supplying the brain are often affected.

Read more on the topic:

Medicines for high blood pressure
High blood pressure and exercise
Thrombosis prophylaxis

Aneurysms

Aneurysms are by far the most common cause of subarachnoid hemorrhage (SAB). This results in bleeding from the vessels supplying the meninges into the superficial layers of the brain tissue. Aneurysms are a bulging of a blood vessel, whereby the vessel walls are additionally stretched and thinner. As a result, there is an increased risk of rupture of the vessel wall with bleeding into the surrounding tissue.

The causes of aneurysms are numerous. A large part of it is predisposed at birth and is aggravated in the course of life by risk factors (e.g. high blood pressure, smoking). In particular, chronically elevated blood pressure leads to further expansion and eversion of the vessel. In the case of very high blood pressure values, the vessel wall can no longer compensate for the blood pressure and a rupture occurs. An aneurysm before rupture usually causes no symptoms or symptoms and is therefore difficult to diagnose.

Read more on the topic: Stroke what are the signs

tumor

Tumors are another cause of cerebral haemorrhage. Tumors that have metastasized into the brain can also lead to cerebral haemorrhage. Due to their partially displacing growth, they can damage and infiltrate (penetrate) the surrounding vessel walls. This increases the risk of bleeding into the brain tissue. Cerebral haemorrhages can be the first symptom of brain tumors or brain metastases.

Read more on the topic: Brain tumor signs, brain metastases

Clotting disorders

Numerous coagulation disorders also increase the risk of bleeding in the brain. Due to an increased tendency to bleed, even slight lesions or fractures in the area of the skull can lead to massive bleeding. This is due to the fact that with an increased tendency to bleed, even very small wall defects cannot be closed and the bleeding is not stopped.

A distinction is made between drug-induced coagulation disorders and congenital coagulation disorders. Drugs that make you more likely to bleed include blood thinners (Anticoagulants) such as heparin, marcumar, apixaban and rivaroxaban. Platelet aggregation inhibitors such as ASA or clopidogrel can also promote cerebral haemorrhage due to an increased tendency to bleed.

Congenital coagulation disorders with an increased tendency to bleed include disorders of the blood platelets (Thrombocytopathies or penias), Haemophilia (blood disease) or the vWF syndrome.

Read more on the topic: Factor 5 disease, protein C deficiency, hepatic insufficiency

Causes in the baby / newborn

Compared to adults, chronically high blood pressure values or tumors are generally no risk factors for cerebral hemorrhage in the newborn. Frequent causes are congenital coagulation disorders or trauma in the newborn. In particular, falls on the head or blows to the skull can lead to rupture of the cerebral vessels and bleeding in newborns. The risk is particularly high within the first days to weeks after the birth, as the development of the vascular walls is not yet complete.

Congenital coagulation disorders that are associated with an increased tendency to bleed include hemophilia A / B, von Willebrandt-Jürgens syndrome or factor V disease.

Diagnosing cerebral hemorrhage in newborns is often difficult because the typical symptoms in newborns are difficult to diagnose.

Read more on the topic: Diseases of premature babies

alcohol

According to numerous studies and studies, the risk of cerebral haemorrhage is increased with long-term high alcohol consumption (women> 12g alcohol per day, men> 24g alcohol per day). The exact mechanisms are not yet fully understood.

In addition, there is an increased risk of falling if you drink a lot of alcohol. The protective reflexes are reduced in the intoxicated state, which also makes it possible to fall heavily on the head. As a result, traumatic brain injuries with bleeding into the brain tissue are possible in some cases.

Read more on the topic: Consequences of alcohol