Stroke of the Medulla Oblongata: What Happens, Survival Rate, and More

A stroke in the medulla oblongata, also known as a medullary stroke, is a rare type of stroke that affects the medulla oblongata, a structure in the brain that transfers nerve messages to the spinal cord. Although rare, medullary strokes are fatal in about 11% of cases. The risk of medullary stroke is highest in people ages 65 and up, and those with arterial disease.

Vertigo, double vision, facial and limb paralysis, and loss of coordination are some of the most common medullary stroke symptoms. The faster you get medical attention for a stroke, the better your chances are of survival. If you are experiencing stroke symptoms, call 911 or get to an emergency room immediately.

This article explains what the medulla oblongata is along with the causes and symptoms of medullary stroke. It also covers how this type of stroke is diagnosed and treated.

What Is the Medulla Oblongata?

The brainstem is the stalk-like feature located at the base of the brain. It is comprised of three sections: the midbrain, pons, and medulla oblongata. The medulla, which sits at the bottom-most part of the brainstem, connects to the spinal cord.

The medulla oblongata is densely packed with nerves that serve a variety of purposes. Some carry sensory information between the brain and spinal cord. Others coordinate various reflexes and autonomic functions that are essential for life.

Function of the Medulla Oblongata

Autonomic functions are those your body does automatically. Autonomic functions controlled by the medulla oblongata include:

• Blood pressure regulation
• Breathing rate and depth
• Heart rate
• Digestion
• Perspiration (sweating)

The medulla oblongata is also your brain's reflex control center. It is responsible for activating such reflexes as:

• Vomiting
• Coughing
• Sneezing
• Gagging
• Pupil dilation
• Defensive reflexes, such as withdrawing your hand when something is hot
• Escape reflexes, such as jumping or flinching when startled
  

Effects of a Medullary Stroke

A stroke of the medulla interferes with vital nerve messages. It can result in a number of serious problems, such as:

• Paralysis on one or both sides of the body
• Double vision
• Coordination problems

A stroke involving the medulla can also interfere with your body's normal breathing, heart function, and other vital autonomic functions. Some people who have this type of stroke may need a machine to breathe.

More severe strokes in the medulla can cause "locked-in syndrome." This is a condition in which people are conscious but cannot move any part of the body except the eyes.

Symptoms of Medullary Stroke

Stroke symptoms can be hard to recognize. A stroke of the brainstem and medulla may at first cause vague symptoms, such as headaches and dizziness. The symptoms can worsen, however, and the stroke may progress rapidly.

Some of the symptoms of a medullary stroke include:

• Severe headaches that start suddenly and get worse when you change positions, bend, strain, or cough
• Double vision
• Numbness in the arm, face or leg on one side
• Weakness of the face, arm or leg on one side
• Dizziness
• Difficulty walking
• Loss of balance or coordination
• Persistent hiccups
• Loss of consciousness

A medullary stroke can cause numbness and sensory problems on one side of the body, and weakness on the opposite side. This is unusual because most other strokes cause sensory problems and weakness on the same side of the body.

There are long nerve pathways that transmit information between the body and the brain. Many of these pathways cross over to the opposite side in the medulla. This causes the unique pattern of symptoms characteristic of medullary stroke.

Risk Factors 

Risk factors for a medullary stroke are the same as the risk factors for strokes in other areas of the brain. They include:

• High blood pressure
• Atrial fibrillation and other heart disease
• Diabetes
• Blood disorders
• A family history of stroke
• Elevated cholesterol and triglycerides
• Age
• Ethnicity
• Illegal drug use
• Smoking
• Physical inactivity
• Hormone replacement therapy
• Birth control pills

It is also possible for a medullary stroke to happen after a sudden head or neck movement injures an artery. This is rare, however.

Diagnosis 

A stroke in the medulla can be more difficult to diagnose than other strokes. This is because symptoms like dizziness, balance problems, and headaches are vague. Usually, a neurologist can identify a medullary stroke during a physical examination. If the symptoms are mild, however, they might not be very apparent in the early stages. 

A brain CT scan or a brain MRI can also be used to diagnose a medullary stroke. A brain MRI is usually considered a reliable test for identifying strokes in this part of the brain.

If there is concern about blood vessels or blood flow, an ultrasound or angiogram may help healthcare providers observe the blood vessels. An ultrasound uses sound waves to visualize internal structures. An angiogram uses X-rays to track how blood moves through the body.

Recovering From a Medullary Stroke 

Recovery from a medullary stroke depends on the size of the stroke and how quickly you were treated. Your rate of healing also plays an important role. 

Strokes of the medulla oblongata do not affect the language or thinking areas of the brain. This can make it easier for you to participate more fully in your rehabilitation.

Summary

A medullary stroke happens in the medulla oblongata, which is located on the brain stem. This part of your brain transfers messages from the brain to the spinal cord and is responsible for many of your body's involuntary functions.

A medullary stroke can cause serious symptoms like paralysis and coordination problems. In severe cases, patients may need a machine to breathe.

Symptoms can be vague at first but may progress to numbness, weakness, and loss of balance. An MRI can help your healthcare provider diagnose this type of stroke.