Brain Hemorrhage

Introduction

The venous drainage of the brain is a complex network of blood-supplying vessels. All the cortical structures depend on the regular supply of oxygenated blood, glucose, and nutrition. Without a properly functioning blood-supply system, the functions of the processing parts of the brain would become impaired.

 

When the brain’s blood flow is obstructed, the neuronal cells don’t receive sufficient oxygen, glucose, and nutrition. If the blood vessels become clogged, if they narrow or rupture, or if there are clots in them, blood flow won’t be strong enough to reach the brain and its processing areas.

 

What Is a Brain Hemorrhage?

 

Brain hemorrhage refers to a type of brain stroke. It occurs after a blood-supplying artery in the brain bursts and causes internal bleeding in the brain.

 

Internal bleeding can reduce the brain’s oxygen supply and create additional pressure on the tissue and the skull. It can lead to the destruction of neuron cells in the brain, so a brain hemorrhage categorizes as a medical emergency and requires immediate treatment.

 

What’s more, a brain hemorrhage prevents the neuron cells from relaying information to other parts of the body, which obstructs their normal functions.

How Does a Brain Hemorrhage Occur?

 

To reiterate, a hemorrhagic stroke occurs when a blood vessel in the brain leaks or bursts and causes bleeding. The excessive bleeding creates compression within the skull. This pressure can be so severe that the blood carrying oxygen, glucose, and nutrition to the cortical structures becomes unable to supply the brain tissue.

What Are the Types of Brain Hemorrhages?

 

Depending on the location where the bleeding occurs, we can distinguish several types of brain hemorrhaging:

 

  • Intracerebral hemorrhage – A type of bleeding that occurs inside the structures of the cerebral cortex.
  • Subdural hemorrhage – This type of brain hemorrhaging occurs below the dura matter’s inner layer and above the brain.
  • Epidural hemorrhage – An epidural hemorrhage occurs when there’s bleeding between the skull and the brain.
  • Subarachnoid hemorrhage – The bleeding occurs between the brain and the meninges that cover the cortical structures.

What Are the Symptoms of a Brain Hemorrhage?

 

Bleeding in the brain can occur due to an accident, stroke, brain tumor, or high blood pressure.

 

The typical brain hemorrhage symptoms include:

 

  • Sudden or severe headache;
  • Loss of consciousness;
  • Seizures;
  • Nausea or vomiting;
  • Changes in vision;
  • Changes in balance;
  • Difficulty talking (slurred speech) or understanding speech;
  • Difficulty using fine motor skills;
  • Weakness, tingling or numbness in one side of the arms or legs;

What Are the Causes of Brain Hemorrhages?

There’s a vast number of risks that can lead to a brain hemorrhage caused by the bursting of a broken artery in the brain. The most common medical threats include:

 

  • Head trauma
  • Stroke
  • Extremely high blood pressure
  • Aneurysm
  • Abnormalities and blockage of the blood vessels
  • Internal bleeding of the brain
  • Thrombus
  • Arteriovenous malformation (AVM)

Head Trauma

Head trauma is the most common cause of bleeding within the structures of the cerebral cortex. A head injury may result from a fall, bicycle accidents, motor vehicle accidents, physical assaults, and sports injuries.

 

Typical forms of head injuries include concussions, scalp wounds, brain lesions, and skull fractures that can be open (penetrating) or closed (haven’t broken the skull). These injuries may result in:

 

  • Bleeding in the tissues of the cerebral cortex,
  • Bleeding in cortical layers.

Stroke

The disruption of blood supply to the brain’s neuron cells can result in a temporary or permanent loss of function of body parts.

 

The typical symptoms of a stroke develop rapidly and include weakness or numbness on one side of the body, problems with vision and speech, and difficulties maintaining balance.

Abnormalities and Blockage of Blood Vessels

More extended periods of high blood pressure or diabetes can cause blockage of arteries. Due to this blockage, a stroke can occur deep within the brain.

 

Brain strokes can also occur due to a blockage triggered by a material fragment that has reached the brain through the blood supply network.

High Blood Pressure

 

This is one of the most common causes of brain hemorrhage. Due to a prolonged period of applying pressure to the blood vessels and the cortical structures, high blood pressure can weaken the arteries’ walls and lead to rupture.

 

When this occurs, blood accumulates in the brain, leading to a brain stroke, i.e. brain hemorrhage.

Aneurysm

Aneurysms are swellings, weakening the walls of blood vessels. They can burst and cause bleeding in the brain, which could lead to a brain stroke. This enlargement of the arteries can lead to fatal complications if ruptured.

 

Aneurysms occur due to numerous causes, including:

 

  • high blood pressure;
  • atherosclerosis;
  • trauma;
  • infections of the artery wall;
  • heredity;
  • abnormal blood flow at the junction between the arteries.

Internal Bleeding of the Brain

The intracerebral hemorrhage, or internal brain bleeding, is one of the main reasons for a stroke in patients dealing with hypertension. High blood pressure may put additional pressure on the brain’s small arteries, which causes them to burst and trigger bleeding.

Brain Thrombus

The deposits of fat on the artery walls reduce blood flow. This may trigger the formation of a blood clot or thrombus in the cerebral vein.

 

When a blood clot forms in the brain’s venous sinuses, it blocks the artery supplying the brain with oxygen. Blood clots tend to occur in brain areas where regular blood flow is interrupted. This blockage always results in a stroke.

 

The risk factors for a brain thrombus include:

 

  • head trauma or injury;
  • protein deficiencies;
  • ear, face, or neck infection;
  • obesity;
  • dehydration;
  • cancer;
  • tumors.

Arteriovenous Malformation (AVM)

 

The abnormal connection between arteries and veins in the brain is called an arteriovenous brain malformation (AVM).

 

While the arteries transmit oxygenated blood from the heart to the cortical structures, the veins return blood to the heart and the lungs. When they get entangled, this vital process is disrupted.

 

An arteriovenous malformation mostly develops in the brain or spine. The affected individuals experience symptoms such as severe headaches or seizures. This medical condition is often diagnosed after a brain scan due to vessel rupture and brain hemorrhaging.

Anatomy and Structure of Brain Veins

 

Brain veins are blood vessels that protrude the arachnoid mater and the layer of the dura mater to deliver nutrients and oxygen through the blood into the dural venous sinuses. The brain’s veins continue to run parallel to the internal jugular veins (IJVs) via the sigmoid sinus from this anatomical point.

What Are the Major Veins of the Brain?

 

The vein system of the brain includes the following structures:

 

  • Superficial middle cerebral veins;
  • Superior and inferior cerebral veins;
  • Internal cerebral veins;
  • The great cerebral vein;
  • The superior and inferior cerebellar veins.

 

Dural venous sinuses are the spaces between the membranes of the brain and the spinal cord that form this anatomical point. The endosteal and meningeal layers receive venous blood from the following structures:

 

  • Superior sagittal sinus;
  • Inferior sagittal sinus;
  • Straight sinus;
  • Transverse sinus;
  • Sigmoid sinus;
  • Cavernous sinus;
  • Sphenoparietal sinus;
  • Superior and inferior petrosal sinuses;
  • Occipital sinus.

In Which Region of the Brain Do Veins Drain?

The veins’ primary function in the brain is to drain the capillary network that supplies it with blood. This allows for the removal of carbon dioxide and other metabolic waste from the cerebral cortex structures, allowing fresh blood to flow in and support the brain’s proper functioning.

 

Brain veins can be divided into 2 sub-categories: superficial cerebral veins and internal cerebral veins.

 

In relation to the brain region they drain into, these veins are further divided into:

 

  • Superficial veins of the cerebrum – They include the superficial cerebral veins, inferior cerebral veins, and the external, middle cerebral vein;
  • Deep veins of the cerebrum – They include the internal cerebral veins, great cerebral vein (of Galen), and the basal veins;
  • Veins of the cerebellum – They include the superior cerebellar veins and the inferior cerebellar veins;
  • Dural venous sinuses include the superior sagittal sinus, inferior sagittal sinus, straight sinus, transverse sinus, sigmoid sinus, cavernous sphenoparietal sinus, petrosal sinus, occipital sinus.

Fun Facts

Did you know?

 

  1. The processing functions of the brain are improved by increased blood flow to the additional supply of oxygen and nutrients.
  2. “Hemo” is the Greek word for blood. Therefore, hemorrhage can be translated as a ‘burst of blood.’
  3. Cerebral hemorrhage, intracranial hemorrhage, or intracerebral hemorrhage are other names for brain hemorrhage.
  4. Amyloid angiopathy is an abnormality of the walls of the blood vessels that sometimes can occur due to the process of aging and high blood pressure.
  5. Hemorrhages are more common in older adults, but they may also occur in the younger population.
  6. When blood accumulates in a section of the brain, it is referred to as a hematoma.
  7. Surgery may be necessary to relieve some of the pressure on the cortical structures caused by severe brain hemorrhaging.
  8. Smoking is also one of the key triggers that contribute to bleeding in the brain. Smoking must be avoided by all means.
  9. People with high blood pressure need to be especially vigilant about their health, must do regular medical checkups, and are strongly advised to take steps toward lowering their blood pressure to prevent a brain hemorrhage.
  10. Many people with diabetes also have high blood pressure, high cholesterol, and are maybe overweight, which are all risk factors for a brain stroke.