List of Modules

Module 1 - Stroke/TIA (Objectives)

What is a stroke?

A stroke is an injury to the brain caused by interruption of its blood flow or by bleeding into or around the brain.  It produces neurologic deficits that have a relatively sudden onset and persist for more than 24 hours.  A stroke can also kill the patient. 

Module 2 - Stroke Risk Factors

Many risk factors have some role in promoting or accelerating atherosclerotic plaque formation and ulceration. This makes sense when you remember that 80% of all strokes are ischemic, and that atherosclerosis plays an important role in most ischemic strokes. However, it is usually thrombus that finishes the job--this is what completely occludes the vessel and is the immediate cause of an ischemic stroke. A thrombus can form locally in a cerebral vessel, or a piece can break off and travel to the brain as an embolus. Therefore, other important risk factors are conditions that promote thrombus formation in locations where it can affect the brain.

Module 3 - The Blood Supply of the Brain

The brain derives its arterial supply from the paired carotid and vertebral arteries. Every minute, about 600-700 ml of blood flow through the carotid arteries and their branches while about 100-200 ml flow through the vertebral-basilar system.

The carotid and vertebral arteries begin extracranially, and course through the neck and base of the skull to reach the cranial cavity. The internal carotid arteries and their branches supply the anterior 2/3 of the cerebral hemispheres, including its deep white matter and the basal ganglia. The vertebral arteries and basilar artery, with their branches, supply the remaining posterior and medial regions of the hemispheres, most of the diencephalon, the brainstem, cerebellum, and cervical spinal cord. 

Module 4 - Ischemia in Carotid Territory

The carotid territory includes the retina and much of the anterior and lateral cerebral hemisphere. Key clinical problems referrable to ischemia in carotid territory involve occlusion of either the extracranial internal carotid artery (ICA) or its intracranial branches, including the ophthalmic artery, middle cerebral artery (MCA) or anterior cerebral artery (ACA).

Module 5 - Ischemia in Vertebral-Basilar Territory

TIAs in the vertebral-basilar territory can produce a number of different problems reflecting the many functions of the brainstem. Because the basilar artery is a single midline vessel with branches supplying both sides of the brainstem, these TIAs can produce bilateral or unilateral motor and sensory findings.

Module 6 - Preventing and Treating Ischemic Stroke

A major goal of evaluating patients who have had a TIA or mild ischemic stroke is to determine the specific cause of the cerebral ischemia, so that the most appropriate therapy can be initiated to prevent recurrence.  As a reminder, the most common causes of cerebral ischemia in patients over the age of 50 are: 

• Embolus
  - Artery to artery
  - Heart to intracranial vessel (cardiogenic emboli)
• In situ thrombus (usually formed on ruptured plaque)
• Small vessel disease, usually secondary to hypertension or diabetes