Neurology Chapter: Stroke and Hemorrhage

Cerebral Vascular Diseases

• Cerebral vascular diseases encompass a range of conditions affecting blood vessels in the brain.
• These conditions can lead to stroke, which is a serious neurological event.
• Stroke statistics show approximately 795,000 people suffer a new or recurrent stroke each year, averaging one stroke every 40 seconds.
• Stroke is the 3rd leading cause of death after cardiovascular diseases and cancer. About 1 of every 18 deaths.
• Ischemic strokes are the most common type (87%). These result from reduced or blocked blood flow to the brain. A variety of factors can cause this condition.
• Hemorrhagic strokes (13%) occur due to brain bleeding. This can result from bursting blood vessels. 3% are subarachnoid hemorrhages and 10% are intracerebral hemorrhages.
• Stroke symptoms vary depending on the affected area of the brain, and these are not fully listed here, but include symptoms such as weakness on one side of the body.
• Transient ischemic attacks (TIAs) are less severe than strokes. These are short-term interruptions in blood flow but do not cause permanent damage. A third of patients with TIAs will develop clinically significant stroke within 5 years.
• Competencies for professionals relating to stroke include understanding pathophysiological mechanisms, correct medical terminology, integrating knowledge from various sciences to understand clinical manifestations, recognizing roles in healthcare teams, relating the etiology to the diagnostic process and understanding the pharmacological approach to treatment.
• Common causes of ischemic stroke include atherosclerosis, embolism, small vessel disease, vascular spasm and other conditions like vasculitis and hypercoagulability.
• A common cause of hemorrhagic stroke is hypertension.
• Other causes of hemorrhagic strokes include rupture of small penetrating arteries and small vessel disease.
• The Circle of Willis is crucial for collateral blood flow within the brain.
• Deep penetrating vessels serve as a critical route of blood supply for specific areas like the basal ganglia and thalamus.

Pathogenesis of Cerebral Infarcts (Stroke)

• Ischemic strokes are divided into thrombotic and embolic types, and lacunar small vessel disease.
• Thrombotic strokes are a result of blood clots (thrombi) that form within the arteries supplying the brain.
• Embolic strokes occur when blood clots (emboli) travel from elsewhere in the body and block a cerebral artery.
• Lacunar strokes are a result of occlusion in small blood vessels of the brain.
• Hemorrhagic strokes are divided into primary brain parenchymal hemorrhage, and subarachnoid hemorrhage.
• Primary brain parenchymal hemorrhage is bleeding within the brain tissue itself, often related to hypertension or small vessel disease.
• Subarachnoid hemorrhage is bleeding into the subarachnoid space, often caused by rupture of a cerebral aneurysm.

Traumatic Brain Vascular Injury

• Epidural hematomas are blood clots that form between the skull and the dura mater. These are often caused by head trauma and can quickly cause dangerous pressure increases.
• Subdural hematomas are blood clots that form between the dura mater and the arachnoid layer. These are commonly seen in elderly people, and can be caused by traumatic events or conditions that cause increased pressure in the brain.

Stroke Warning Signs

• Spotting a stroke early is of paramount importance.
• Utilize the FAST method to quickly assess warning signs:
  • Face drooping
  • Arm weakness
  • Speech difficulty
  • Time to call 911
  • Additional warning signs, if present, may also indicate a stroke, and should be taken seriously.