A stroke occurs when blood flow to a section of the brain is interrupted, depriving brain cells of oxygen and nutrients. This disruption can result from a blockage, known as an ischemic stroke, or from bleeding, known as a hemorrhagic stroke. While relatively uncommon, a direct mechanical link exists where a sudden physical force can injure the vessels supplying the brain. The primary way a fall can cause a stroke involves trauma to the arteries in the neck, which then leads to a clot that travels to the brain. This specific cause is important because the resulting symptoms can be delayed, making the connection to the initial injury less obvious.
Cervical Artery Dissection: The Direct Mechanism Linking Falls and Stroke
The primary process that connects a fall to an ischemic stroke is called Cervical Artery Dissection (CAD), which involves a tear in the wall of one of the four main arteries supplying the brain. These arteries include the two carotid arteries at the front of the neck and the two vertebral arteries at the back. A forceful fall, especially one involving a sudden, severe hyperextension or rotation of the neck, can mechanically stress these vessels.
The force causes a small tear in the innermost lining of the artery wall, called the intima. Blood then seeps into the layers of the artery wall itself, a process called dissection. This pooling of blood within the wall can either narrow the vessel, restricting blood flow, or lead to the formation of a blood clot (thrombus) at the injury site.
If that clot breaks loose, it travels up the bloodstream and lodges in a smaller artery within the brain, cutting off blood supply and causing an ischemic stroke. The location of the tear determines the area of the brain affected; Carotid Artery Dissection typically affects the front of the brain, and Vertebral Artery Dissection impacts the back of the brain and the brainstem.
The neurological symptoms of the stroke do not always appear at the moment of injury; they can be delayed by several hours, days, or even weeks after the fall. This delay occurs because it takes time for the clot to form, enlarge, and then travel to the brain. A history of even minor trauma to the head or neck should raise suspicion if neurological symptoms later develop.
The Reverse Scenario: When a Stroke Causes the Fall
While a fall can cause a stroke through cervical artery dissection, a far more common scenario involves the causality being reversed: a stroke or a Transient Ischemic Attack (TIA) occurs first, which then causes the person to fall. This sequence is observed because a sudden neurological event immediately compromises physical stability.
A stroke may cause sudden muscle weakness or paralysis on one side of the body, known as hemiparesis. This immediate loss of strength results in the legs buckling or the body collapsing to the weak side. Similarly, a stroke affecting the back of the brain can cause severe vertigo or poor coordination, leading to instantaneous loss of balance and a subsequent fall.
Other sudden neurological deficits that precede and cause a fall include acute vision loss or a profound sensory disturbance. In many cases, a fall is the very first external sign that a person is experiencing a stroke. Anyone who experiences an unexplained fall, particularly without a clear trip or external cause, should be evaluated for a potential neurological event. Understanding this sequence helps frame the fall not as the cause of the stroke, but as a symptom of the stroke itself.
Recognizing and Responding to Symptoms After a Fall
Following any significant fall or neck trauma, it is important to monitor for signs of a potential stroke, even if the symptoms do not appear immediately. The standard warning signs of a stroke include sudden facial drooping and unexpected weakness or numbness in one arm. Any sudden difficulty with speech, such as slurring words or being unable to find the right words, also requires emergency attention.
These symptoms signal that blood flow to the brain is compromised and mandate an immediate call for emergency medical services. Time is essential in treating a stroke, as rapid intervention can significantly limit brain damage. Even if the symptoms are brief and resolve on their own, a TIA may have occurred, which is a powerful warning sign of a full stroke.
In cases where a cervical artery dissection may have occurred, specific localized symptoms can also develop. These include a new and unusually severe headache or severe pain in the neck or face. Another specific sign of dissection is pulsatile tinnitus, a whooshing sound in the ear that beats in time with the heartbeat.
Other dissection-related symptoms can include a painful, drooping eyelid combined with a small pupil (Horner’s syndrome), double vision, or difficulty swallowing. Because the stroke symptoms caused by dissection can be delayed, any person who experiences a severe neck or head injury should remain vigilant for these localized symptoms in the weeks following the fall.