In a new Netflix documentary, country singer Shania Twain talks about how she "thought [she had] lost [her] voice forever" after contracting Lyme disease. Writing for MedPage Today, Michelle Berman details the symptoms of Lyme disease and explains how the condition is diagnosed and treated.

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Shania Twain's symptoms

In 2003, Twain said she contracted Lyme disease after she was bitten by a tick while horseback riding.

"My symptoms were quite scary because before I was diagnosed, I was on stage very dizzy. I was losing my balance. I was afraid I was gonna fall off the stage," Twain said. "I was having these very, very, very millisecond blackouts, but regularly, every minute or every 30 seconds."

One of the most devastating symptoms for Twain was the toll the disease took on her voice. "My voice was never the same again. I thought I'd lost my voice forever," she said.

In a TV interview, Twain noted that, "It was a good 6 or 7 years before a doctor was able to find out that I had sustained nerve damage to my vocal cords, directly caused by Lyme disease."

Twain started to believe that she would never be able to sing again. However, after she underwent two "open throat" vocal cord surgeries, along with vocal therapy, she started to get her voice back.

What you need to know about Lyme disease

Lyme disease is the most common vector-borne disease in the United States. It is typically caused by the bacterium Borrelia burgdorferi, and in rare cases can be caused by the Borrelia mayonii bacterium. The disease is transmitted to humans through the bite of an infected blacklegged tick.

In the United States, the disease is typically seen in the Northeast and upper Midwest, with approximately 40 infections per 100,000 people. Usually, the disease is contracted between late spring and early fall.

When left untreated, a variety of symptoms can appear. Different symptoms can manifest depending on the stage of infection—an early infection occurs three to 30 days after a tick bite, and a late infection occurs days to months after a tick bite.

With an early infection, symptoms can include fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes.

Roughly 70% to 80% of infected individuals will also develop a rash, called erythema migrans, where they were bitten. The rash typically appears after a delayed onset of 3 to 30 days, with an average of seven days. They often expand over the course of several days and can grow up to 12 inches or more horizontally.

According to Berman, late symptoms of Lyme disease include:

• Severe headaches and neck stiffness
• Additional erythema migrans rashes on other parts of the body
• Facial palsy
• Arthritis with severe joint pain and swelling, often in the knees or other large joints
• Intermittent pain in tendons, muscles, joints, and bones
• Heart palpitations or an irregular heartbeat, known as Lyme carditis
• Episodes of dizziness or shortness of breath
• Inflammation of the brain and spinal cord
• Nerve pain
• Shooting pains, numbness, or tingling in the hands or feet

Unfortunately, Lyme disease can be difficult to diagnose. For instance, many of the symptoms, including headache, dizziness, and joint and body pain, are common symptoms in other conditions.

To diagnose Lyme disease, CDC recommends a two-step testing strategy that includes a conventional enzyme-linked immunoassay (ELISA) test, followed by a Western blot test. For the ELISA test, a blood sample is used to detect antibodies. Notably, the test is very sensitive, and most people who have the disease—and even some who do not—will test positive. If a person tests negative, "it is highly unlikely that the person has Lyme disease, and no further testing is recommended," Berman writes. If a person tests positive or inconclusive, CDC recommends a Western blot test to confirm the results.

Early diagnosis and treatment are key because they can help prevent symptoms of late Lyme disease.

Treatment depends on the age of the patient and the stage of the disease. Doctors recommend a 10-day course of doxycycline for patients older than 8 years with localized disease. A 14-day course of amoxicillin or cefuroxime is often prescribed for children under 8.

For patients with more severe symptoms, including arthritis, AV block, carditis, meningitis, or encephalitis, longer courses of medication or parenteral antibiotics may be prescribed.

While most people will recover after they receive the recommended treatment, roughly 5% of patients will experience lingering symptoms, including fatigue, pain, joint or muscle aches, and difficulty thinking. According to Berman, post-treatment Lyme disease syndrome (PTLDS) can linger more than six months after treatment.

Scientists still do not know the cause of PTLDS, but some researchers believe that it occurs when Borrelia burgdorferi triggers an autoimmune response that causes symptoms to linger after the infection is gone. Currently, there is no proven treatment for PTLDS, but patients typically recover with time. (Berman, MedPage Today, 9/1)