What is Foville Syndrome?
Foville syndrome is a rare condition that affects the lower part of the pons, a part of the brain. It was first identified in 1858 by Achille Louis Francois Foville, an anatomist and psychiatrist. He first described the syndrome through his study of a 43-year-old man who had unusual eye and face muscle paralysis, along with impaired movement on one side of his body. Today, we understand Foville syndrome as typically presenting with problems moving the eyes, facial paralysis, and impaired movement on the opposite side of the body. Other symptoms can include reduced facial sensitivity, hearing problems, unsteady movements, pain, and decreased sensitivity to temperature.
The pons is a large section of the brain that lies above the medulla. It has thick fiber bundles called the cerebral peduncles at the top and front, and other bundles called pyramids at the bottom. It’s connected to the cerebellum, a part of the brain at the back, by bundles called the middle cerebellar peduncles. Several crucial nerves, which send signals from the brain to different parts of the body, originate from or move through the pons.
The pons can be divided into two main sections – the basilar portion at the front and the tegmentum at the back. Alternatively, it can be divided into superior and inferior parts.
In the lower section of the pons, voluntary movements are controlled by tracts called corticospinal tracts. The pons also has what’s known as a medial lemniscus, which carries sensations of touch and body position from the body to the brain. There are also structures involved in hearing and tracts that send signals to the brain important for staying awake and paying attention. The facial nerve, which controls facial muscles, also originates here.
Corticopontine fibers, which help with voluntary movement, descend from the different parts of the cerebral cortex to the pons. The trigeminal nerve, which carries sensation from the face to the brain, has two main branches in this region.
The pons receives its blood supply from the basilar artery, which branches off to supply different sections of the lower pons.
What Causes Foville Syndrome?
Foville syndrome is usually caused by something we doctors call a pontine infarction. This means that a part of your brain called the pons, which is responsible for many critical body functions, didn’t get enough blood. Some other things that can cause Foville syndrome include a hemorrhage (bleeding), granulomas (an area of inflammation in tissue), and tumors in the pons.
While these kind of pontine strokes represent only 3% of all strokes where blood supply is cut off, they can occur due to a disease where fatty deposits build up in the arteries. These fatty deposits, or plaques, in the main artery of the brain can spread into smaller blood vessels, blocking them and leading to tissue damage. Some other potential causes include diseases of the small blood vessels and blood clots originating from the heart.
The damage to the pons due to this kind of stroke results in several nerves not working properly. Some of the structures in the brain that can be affected include the abducens nucleus, intrapontine facial nerve fibers, and the CST (a bundle of nerve fibers running from the brain to the spine). In severe cases, it can involve more structures in your brain. These include the MLF, PPRF, a part of the brain involved in feeling called the spinal trigeminal nucleus, a nerve track important for sensation called the medial lemniscus, a part of the brain that controls eye movements called the vestibuloocular nucleus, the middle cerebellar peduncle afferent fibers, and sympathetic fibers which regulate various functions in the body.
Risk Factors and Frequency for Foville Syndrome
Foville syndrome is a rare condition caused by a stroke in the brainstem. This syndrome is sometimes confused with another condition called Raymond-Cestan syndrome, also known as “superior Foville syndrome”. In contrast, Classic Foville syndrome is sometimes called “inferior Foville syndrome” in medical literature.
Signs and Symptoms of Foville Syndrome
Foville syndrome is a type of stroke that affects the brainstem. It’s often associated with issues related to the nerves controlling functions like eye movement, facial expression, and sensation. The severity and symptoms can vary a lot, depending on exactly what causes it and what areas are affected. For instance, if the damage is in the lower part of a structure called the pons, it could affect certain nerves and result in issues like a lack of coordination or a condition known as Horner syndrome.
This syndrome is often linked to diseases of the blood vessels and heart. Many people who have it also have high blood pressure, high lipid levels in their blood, a smoking history, or diabetes. If someone has a history of a certain type of irregular heartbeat (atrial fibrillation) and is taking blood thinners, it could suggest Foville syndrome might be due to a clot or bleeding in the brain.
During a medical examination, doctors will check vitals like blood pressure and heart rhythm. They could perform an eye exam, which might show signs of vessel disease. In people with ongoing heart issues, they might hear abnormal heart sounds or rhythms. A neurological exam might show signs pointing to Foville syndrome:
- Abducens nerve palsy: This shows as an inability to move the eye on the same side as the affected area.
- Facial nerve palsy: This means weakness of the upper and lower face on the same side as the affected area.
- Vestibulocochlear nuclear palsy: This results in hearing loss on the same side as the injury.
- Trigeminal nuclear palsy: This involves losing sensation in the face on the same side as the injury, including touch, pain, and temperature sensations.
- Signs of damage to pathways located throughout the entire body might include weakness on the opposite side of the body, sensation loss on the opposite side of the body, or signs of Horner’s syndrome, which includes a drooping eyelid, small pupil, and lack of ability to sweat on the same side as the brain lesion.
A person might also show signs of uncoordinated movement of the limbs on the same side as the injury. These may be signs of damage to nerve fibers that play a key role in planning and coordinating movement.
Testing for Foville Syndrome
If you’ve been brought into a hospital with symptoms of a stroke, various tests are done to understand what’s happening in your brain. A common way to quickly visualize what’s going on is with a type of imaging called a computed tomography (CT) scan. It’s an efficient way to locate the potential stroke area and determine what type of stroke you’re experiencing – either ischemic (blood flow to the brain is blocked) or hemorrhagic (bleeding in the brain).
In some situations, you might also have a magnetic resonance imaging (MRI) scan. This scan gives better images of your brain’s soft tissues, which can help to detect other issues like tumors or inflammation. If your doctor is considering that a blood vessel issue may be causing your symptoms, they might also do an MRI or CT angiography, which provides more detailed images of your blood vessels.
In addition to imaging scans, your heart’s health may also be evaluated to see if it is sending blood clots to your brain and causing a stroke. This includes an electrocardiogram to check your heart’s rhythm, and potential blood tests for heart enzymes (to see if you might be having a heart attack), cholesterol levels, and blood sugar or HbA1c levels (to spot any conditions that could increase your risk for strokes). Other blood tests like prothrombin time, partial thromboplastin time, or bleeding time could be done to see if your blood is clotting correctly. Sometimes, Doppler ultrasound of your legs may also be performed to check for diseases in your leg arteries as well.
Treatment Options for Foville Syndrome
Foville syndrome is typically caused by a form of arterial vascular disease which is a disease of the blood vessels. Patients with this syndrome are often treated in a similar way to other stroke patients. The nature of the treatment primarily depends on how quickly the patient gets medical help after the onset of symptoms. If a patient reaches hospital within 4.5 hours of symptom onset, they may receive thrombolytic therapy, which is a treatment that works to dissolve dangerous clots in blood vessels and improve blood flow. Treatments that work to physically remove or break up blood clots usually aren’t recommended for strokes caused by small-vessel disease.
The long-term treatment for this type of stroke includes taking medication to prevent the formation of blood clots (antiplatelet therapy), controlling risk factors like high blood pressure, diabetes, and high cholesterol, giving up smoking, and following the stroke guidelines of the American Heart Association (AHA). Stroke patients should begin receiving these treatments as soon as they are admitted to the hospital. After a stroke, patients typically work with physical therapists and occupational therapists to help regain physical abilities that may have been affected by the stroke. After they leave the hospital, follow-up care and monitoring for complications is important.
Over time, advancements in acute stroke treatments, expanded uses of thrombolytic therapy, and better techniques for physically removing or breaking up clots have led to improvements in stroke outcomes. However, stroke is generally a chronic condition and there is often a need for ongoing treatment and rehabilitation to address any lasting effects of the stroke.
The AHA suggests that rehabilitation programs should be tailored to the individual needs of each stroke survivor, taking into account their specific health problems and the extent of their disabilities. Outpatient stroke prevention clinics can provide patient-centered care for stroke survivors, taking into account not just their medical needs but also their personal preferences and life circumstances.
What else can Foville Syndrome be?
If a person shows symptoms of Foville syndrome, a number of other health problems could be causing it. These health problems need to be ruled out before a Foville syndrome diagnosis can be made:
- Tumors (neoplastic processes)
- Hemorrhages
- Inflammatory disorders
- Vascular anomalies like arteriovenous malformations
- Guillain-Barré Syndrome
- Exposure to harmful neurotoxins
- Multiple sclerosis
- Wernicke encephalopathy
- Malingering
- Other pontine stroke syndromes like Brissaud-Sicard syndrome/li>
Diagnosing Foville syndrome is a complex process. It involves the doctor taking a detailed history of the patient’s health, and conducting neurological tests, imaging studies, and lab tests. For this reason, it’s often necessary for them to work with neurologists and other health specialists. This helps them find the cause of the patient’s symptoms and decide on the best treatment.
What to expect with Foville Syndrome
Long-term outcomes for stroke patients have been a subject of several research studies. A study by Zhao et al, which involved 281 patients with specific types of stroke, showed that most patients with strokes affecting the paramedian arteries generally had good recoveries. This good recovery was defined as a score of less than 2 on the modified Rankin scale, a measurement system used to determine the degree of disability or dependence in daily activities of people who have suffered a stroke.
However, there are several factors that may affect how well patients recover. These include the severity of the stroke, the type (with hemorrhagic strokes, caused by bleeding in the brain, usually leading to worse outcomes than ischemic strokes, caused by blood clots), how quickly treatment is started, how well the patient responds to treatment, and whether the patient adheres to treatment and rehabilitation plans after the stroke.
Possible Complications When Diagnosed with Foville Syndrome
Complications that may occur after having a stroke can range from additional strokes and falls to deep vein thrombosis (a condition where a blood clot forms in a deep vein, usually in the leg). More complications include a blockage in the lung’s main artery or one of its branches (pulmonary embolism), infections in the chest and urinary tract, pain, pressure sores, as well as mental health problems like depression and anxiety.
Preventing and handling these complications becomes critical during the recovery and long-term care phases after a stroke.
Issues Following a Stroke:
- Additional strokes
- Falls
- Deep vein thrombosis (blood clots in deep veins, typically in the leg)
- Pulmonary embolism (blockage in the lungs)
- Chest and urinary tract infections
- Pain
- Pressure sores
- Depression or anxiety
Preventing Foville Syndrome
The main ways to prevent Foville syndrome, a rare neurological condition, involve maintaining healthy habits, sticking to treatment plans for high blood pressure and diabetes, quitting smoking, limiting alcohol consumption, learning about stroke prevention, and having regular health check-ups. Monitoring your health allows your doctor to catch conditions like high blood pressure, cancer, irregular heartbeat (atrial fibrillation), and other factors that can increase the risk of Foville syndrome.
Further preventive actions include using medications that lower the risk of blood clots (antiplatelet therapy) and lower cholesterol (statin therapy), continuing to avoid smoking, making lifestyle changes, and managing high blood pressure, diabetes, and high cholesterol (hyperlipidemia). All these steps can help reduce the risk of getting Foville syndrome.