What is bell’s palsy?

Bell’s palsy is a condition named after Sir Charles Bell, a Scottish surgeon who first described the characteristic symptoms of this disorder in the 19th century. Bell’s palsy is considered the most common cause of one-sided facial paralysis, affecting approximately 15 to 30 individuals per 100,000 each year. Yet, despite its prevalence, the exact causes behind this condition remain unknown, leaving many to wonder about the details of this neurological condition.

What is Bell’s Palsy?

Bell’s palsy is a condition that produces a sudden, temporary weakness or paralysis of the facial muscles on one side of the face. This phenomenon is caused by inflammation and swelling of the seventh cranial nerve, also known as the facial nerve which is responsible for controlling the movements of the facial muscles.

Bell’s Palsy symptoms

The main symptom of Bell’s palsy is the sudden start of facial muscle weakness or paralysis, typically on one side of the face. This can result in a variety of visual cues, including:

• Drooping of the forehead, eyebrow, and eyelid on the affected side
• Difficulty closing the eye on the affected side
• A lopsided or asymmetrical smile, with the corner of the mouth pulling towards the unaffected side
• Drooling or difficulty retaining saliva on the paralysed side of the face

Individuals with Bell’s palsy may also experience:

• Facial numbness or a heavy, “numb” sensation
• Increased sensitivity to sound (hyperacusis) on the affected side
• Reduced, altered or loss of taste
• Excessive tearing or dryness in the eye on the paralyzed side
• Mild pain or discomfort around the jaw or behind the ear on the affected side
• Headaches or a general feeling of malaise

It is important to note that the severity of symptoms can vary greatly, ranging from mild weakness to complete paralysis of the facial muscles.

Causes and risk factors of Bell’s Palsy

The exact cause of Bell’s palsy remains largely unknown, but it is often associated with viral infections. Researchers have identified several viruses that may contribute to the development of this condition, including:

• Herpes simplex virus (the virus responsible for cold sores and genital herpes)
• Varicella-zoster virus (the virus that causes chickenpox and shingles)
• Epstein-Barr virus (the virus that causes infectious mononucleosis)
• Cytomegalovirus
• Adenoviruses (responsible for respiratory illnesses)
• Rubella virus
• Mumps virus
• Influenza B virus
• Coxsackievirus (the cause of hand-foot-and-mouth disease)

These viral infections are believed to trigger an inflammatory response that leads to swelling and irritation of the facial nerve, ultimately resulting in the characteristic symptoms of Bell’s palsy.

In addition to viral infections, several other risk factors have been associated with an increased likelihood of developing Bell’s palsy, including:

• Pregnancy, especially during the third trimester or in the first week after childbirth
• Diabetes
• High blood pressure (hypertension)
• Obesity
• A weakened immune system due to factors like stress, illness, or sleep deprivation
• Herpes zoster (chickenpox and shingles)
• A personal or family history of Bell’s palsy

It is important to note that while these risk factors may increase the likelihood of developing Bell’s palsy, the condition can occur in individuals without any identifiable predisposing factors.

Diagnosing Bell’s Palsy

Diagnosing Bell’s palsy typically involves a comprehensive medical evaluation by a healthcare professional, such as a neurologist or an otolaryngologist (ear, nose, and throat specialist). The diagnostic process typically includes:

• Medical history and physical examination: The healthcare provider will conduct a thorough review of the patient’s medical history, focusing on the onset and progression of the symptoms. They will also perform a physical examination, assessing the extent of facial muscle weakness or paralysis and evaluating other neurological functions
• Neurological tests: The healthcare provider may order additional tests to rule out other potential causes of facial paralysis, such as a stroke, Lyme disease, or a tumour. These tests may include electromyography, Magnetic Resonance Imaging and Lumbar puncture
• Blood tests: Depending on the suspected underlying cause, the healthcare provider may order blood tests to screen for conditions like Lyme disease, sarcoidosis, or certain viral infections

Treatment options

The treatment and management of Bell’s palsy typically focus on relieving symptoms, promoting nerve recovery, and preventing potential complications. The standard approach often involves a combination of the following strategies:

• Corticosteroid medications: Oral corticosteroids, such as prednisone, are commonly prescribed to help reduce the inflammation and swelling of the facial nerve
• Antiviral medications: Healthcare providers may also prescribe antiviral medications, such as acyclovir or valacyclovir, in conjunction with corticosteroids
• Eye care: Eye drops, lubricants, or even temporary eye patches to protect the affected eye and prevent dry eye
• Physical therapy and facial exercises: Gentle facial exercises and physical therapy can help maintain muscle tone and prevent muscle atrophy
• Electrical Stimulation: Help prevent muscle wasting and potentially speed up the recovery process
• Surgical Interventions: In rare cases, nerve decompression or facial reanimation procedures, to help restore facial function

Complications and long-term consequences

While Bell’s palsy is generally not a serious or life-threatening condition, it can lead to several potential complications if not properly managed. These complications may include:

• Cornea damage
• Synkinesis (involuntary muscle contractions)
• Permanent facial paralysis
• Psychological and emotional impacts

To reduce these potential complications, it is crucial for individuals with Bell’s palsy to follow the treatment plan recommended by their healthcare provider and to seek prompt medical attention if any new or worsening symptoms arise.

Prevention

Unfortunately, there is no known way to prevent the development of Bell’s palsy, as the exact causes of the condition remain largely unknown. However, some ways may help reduce the risk and the severity of the condition:

• Manage underlying health conditions: Individuals with conditions like diabetes, high blood pressure, or a weakened immune system should work closely with their healthcare providers to optimise the management of these underlying health issues, as they are known risk factors for Bell’s palsy
• Maintain a healthy lifestyle: Practices like getting enough sleep, managing stress, and maintaining a balanced diet may help support the immune system and potentially reduce the risk of developing Bell’s palsy
• Seek prompt medical attention: If you experience any sudden or unexplained facial weakness or paralysis, it is crucial to seek medical attention immediately. Early diagnosis and treatment can significantly improve the chances of a full recovery
• Consider vaccination: While there is no specific vaccine for Bell’s palsy, getting vaccinated against certain viral infections, such as the flu or chickenpox, may help reduce the risk of developing the condition

It’s important to note that even with these preventive measures, Bell’s palsy can still occur, as the underlying causes are not fully understood. However, being proactive about your health and seeking prompt medical attention can help mitigate the potential impact of this condition.

Conclusion

Bell’s palsy, a condition that has captivated the medical community for centuries, remains a complex neurological phenomenon. While the exact causes are still unknown, the advancements in understanding, diagnosis, and treatment have significantly improved our understanding and quality of life for those affected.

Sources

• Bell’s palsy – Symptoms and causes – Mayo Clinic
• Bell’s Palsy: What It Is, Causes, Symptoms & Treatment
• Bell’s Palsy | National Institute of Neurological Disorders and Stroke
• What Is Bell’s Palsy? – American Academy of Ophthalmology