Subarachnoid Hemorrhage: Signs, Causes, Risk Factors and Treatment

Subarachnoid hemorrhage is a life threatening neurological disorder. It is a condition that is caused due to hemorrhage in the subarachnoid space, an area between the brain and skull. Hemorrhage in subarachnoid space can occur due to head injury, ruptured aneurysm and arteriovenous malformation (AVM).

Subarachnoid space is normally filled with cerebrospinal fluid (CSF); it acts as a cushion between the brain and skull.  Bleeding in this space can irritate the brain lining or increase pressure on brain causing damage to the brain cells.

At the same time the area of brain does not receive sufficient amount of blood due to leakage from the brain artery. Hence patient suffers from stroke and in some cases it may lead to coma and death of the person. Subarachnoid hemorrhage in majority of cases is caused due to rupture of aneurysm.

Symptoms of Subarachnoid Hemorrhage

Subarachnoid hemorrhage develops with dramatic suddenness. One of the characteristic features is violent headache. The sudden headache is like a ‘bolt from the blue’.

Patients often describe this headache as a worst headache they have ever suffered in their life. Some patients may also feel a popping sensation before the hemorrhage and headache. This is followed by several other symptoms of brain irritation. Headache is mainly located at the base of skull. Accompanying symptoms along with headache are as follows:

  • Stiffness of neck
  • Vomiting
  • Confusion
  • Increased irritability
  • Slurred speech
  • Numb feeling all over the body
  • Photphobia or sensitivity to light
  • Blurred vision
  • Double vision
  • Disorientation
  • Seizures
  • Hemorrhage in the retina of the eyeball
  • Loss of consciousness
  • Sudden and sharp rise in blood pressure

Usually no paralysis is seen, but if the hemorrhage ruptures in the cerebrum or if there is associated arterial spasm, then patient may also suffer from paralysis. This may depend on the site of damage in the brain.

Causes of Subarachnoid Hemorrhage

Variety of factors can cause subarachnoid hemorrhage.

Brain aneurysm: In majority of cases the cause of subarachnoid hemorrhage is aneurysm of artery and rupture of the aneurysm. Spontaneous subarachnoid hemorrhage is linked with rupture of aneurysm. Aneurysm is formation of balloon like bulge in the weak artery. When the weak arterial wall is not able to bear the pressure of blood flowing through it, the balloon may rupture causing hemorrhage in the area where the rupture has occurred. In this case the blood is released in the subarachnoid space. Risk factors for aneurysm include smoking, alcohol and uncontrolled high blood pressure.

Arteriovenous malformation: It is a congenital disorder. In this condition a complex web of abnormal artery and vein develop. It leads to communication of blood between the vein and artery through the fistula or a passage. This malformation usually occurs in brain and spinal cord. Aneurysm can develop in such malformed blood vessel which may break and release blood in the subarachnoid space.

Brain trauma or serious head injury can also cause subarachnoid hemorrhage; for example in case of car accident or fall from a height where the head is severely injured.

Risk Factors

  • Most cases are known to occur in women.
  • Risk increases after 50 years.
  • Cigarette smoking
  • Heavy alcohol drinking
  • Drugs like cocaine
  • High blood pressure increases risk of rupture of existing aneurysm.
  • Associated diseases such as polycystic kidney, neurofibromatosis etc.

Diagnosis and Treatment

Diagnosis: Subarachnoid hemorrhage is usually diagnosed from the symptoms and physical examination. However, doctors confirm the diagnosis with the help of CT scan, MRI, lumbar puncture, and angiogram.

Treatment: Subarachnoid hemorrhage is an emergency. Person must be immediately sifted in a hospital. Rapid treatment is absolutely necessary to save the life and prevent further damage to the brain. Treatment will depend on the underlying cause as well as the extent of damage to the brain because of hemorrhage. Treatment consists of following:

  • Complete bed rest in a quiet room with slightly elevation of head for six weeks is extremely beneficial.
  • During this period all forms physical strain to the patient must be avoided. For example coughing, sneezing and straining during bowel motion must be avoided and taken care of with medication whenever need arises. A mild laxative is beneficial for easy passage of stool.
  • Blood pressure is monitored and controlled to near normal level with medicines.
  • To control severe headache mild sedative or analgesic is administered.
  • Prophylactic medicines are given to prevent seizures.

If subarachnoid hemorrhage is caused due to rupture of aneurysm, it may need surgical repair to stop bleeding. Surgery is performed with clips. The clips are placed around the neck of aneurysm to stop bleeding. Another method used is endovascular coiling.