While ischemic strokes happen when the blood flow to a part of the brain is interrupted, a hemorrhagic stroke is caused when there is bleeding into brain tissue that kills blood cells.
A cerebral hemorrhage can take several forms:
- Intracerebral hemorrhages. This is bleeding inside the brain. The symptoms and prognosis of an intracerebral bleed vary depending on the size and location of the bleed.
- Subarachnoid hemorrhages. This is bleeding between the brain and the membranes that cover the brain.
- Subdural hemorrhages. This is bleeding between the layers of the brain’s covering (the meninges).
- Epidural hemorrhages. This is bleeding between the skull and the covering of the brain.
Causes
There are several causes of bleeding inside the skull, including:
- Head injuries. For people under the age of 50, this is the most common cause of hemorrhage inside the skull. In the elderly, subdural hematoma after relatively minor head injury is not uncommon.
- Arteriovenous malformation (AVM). This is an anatomical abnormality in the arteries or veins in or around the brain. Such an abnormality may be present from birth, but it is only detected if symptoms develop. Symptoms resulting from bleeding of an AVM vary, depending on size and location.
- Aneurysm. This is a weakening in a blood vessel wall that swells. The thin walls of an aneurysm can burst and cause bleeding into the subarachnoid space and the brain, leading to hemorrhagic stroke.
- Hypertension. Poorly controlled hypertension over a long period of time can weaken blood vessel walls and increase the risk of intracranial bleeding.
- Amyloid angiopathy. This is an abnormality in the blood vessel walls. It occurs with increasing frequency with aging. It may cause many small, asymptomatic hemorrhages prior to causing a large symptomatic one.
Symptoms
The symptoms of bleeding inside the skull tend to come on rapidly and include the following:
- A sudden headache
- Steadily increasing neurologic losses, such as weakness, inability to move (paralysis), numbness, loss of speech or vision and confusion
- Nausea and vomiting
- Seizures
- Loss of consciousness
Diagnosis
On the basis of symptoms, the doctors may strongly suspect bleeding inside the skull. In this setting, CT scans of the brain remains the test of choice. If the CT scan does not confirm the diagnosis, a lumbar puncture (spinal tap) can be used to confirm or rule out subarachnoid hemorrhage. A lumbar puncture may also be needed if infection of the brain or its covering layers is suspected. MRI/MRA, CT angiogram and/or contrast angiography may be needed to complete the diagnosis and enable the doctors to decide on the proper treatment.
Treatment
Treatment for intracranial bleeding varies, depending on the underlying abnormality that caused the bleeding, the location of the bleeding and the size of the blood clot.
The multidisciplinary team at the Stroke Program brings to the table the best of diagnostic radiology, interventional radiology, neurosurgery and neuromedical management.
Diagnostic radiology involves the use of various types of scans to precisely identify the nature and location of the hemorrhage.
Interventional radiology involves treatments that include passing a catheter to widen or to close off blood vessels in the brain without surgery. Other types of interventional radiology involve using focused radiation to correct abnormal blood vessels that have bled into the brain.
Finally, microsurgical techniques can be used to treat abnormal or leaky vessels.