The reason for her face twitching was surprisingly simple | Medical Mysteries

After undergoing six root canals over the years, Tippy McInerny wasn’t surprised when her dentist gave her several shots of a local anesthetic and stretched her mouth open for more than an hour while repairing a filling on her right back molar.

But the numbness in her right cheek lasted for two days, longer than normal. And a few weeks later, strange sensations surfaced on her face, especially around her right eye.

“It felt like someone took my eyeball out and put a little sweater on it. I could see perfectly, but it just felt fuzzy,” said McInerny, who also reported feeling a “low-grade buzz” on the right side of her face.

The next month, as the retired massage therapist sat at home in suburban Minneapolis, her right eye “suddenly started fluttering and blinking — just constant blinking.” The right corner of her mouth began to jerk up to her cheek, as if pulled by a string.

Fearing a stroke, McInerny went to the emergency room, where tests could not explain the spasms. As the contortions worsened over time and became obvious to other people, the outgoing woman who likes to strike up conversations with strangers at the grocery store became a near-recluse, a hardship she said she found even more devastating to her sense of self than two divorces and the deaths of loved ones.

Finally, after three brain scans and visits with eight doctors over 28 months, she got a surprisingly simple answer to why her face was writhing out of control. She also tried a treatment, which was more invasive than others previously recommended to her and came with a risk of significant side effects.

The prolonged uncertainty and isolation was frustrating, she said: “You need to know why. You have to advocate for yourself.”

When McInerny’s face began to tingle and her eye started to feel fuzzy in February 2022, she suspected a connection to her dental work the month before.

Maybe the shots of Novocain-like anesthetic had struck a nerve, she figured. Maybe she was allergic to the drug, though she had never had problems before. Maybe keeping her mouth open for so long, as the dentist and an assistant pulled her lips back, had caused tissue damage.

Worried about her vision, she saw her eye doctor, who said everything looked fine. But when the twitching emerged around her eye and her mouth in March 2022, it felt like a puppeteer had taken control of her head. “It’s really weird when your body’s moving and you’re not making it move,” said McInerny, now 63.

At the ER, blood tests and checks of her speech, balance, and reflexes found no sign of stroke or other ailments. She went to her regular doctor, who dismissed any link to the dental work and ordered an MRI of her head.

McInerny then saw a neurologist, who said the MRI showed nothing abnormal. As she sat with him, her face quivered. He said she had hemifacial spasm, a rare nervous system condition characterized by muscles that twitch on one side of the face. It is normally caused by a blood vessel that compresses, or pulses against, one of two facial nerves, which branch across each side of the face. The condition can also be caused by a tumor, a nerve injury or other abnormalities.

But for McInerny, the neurologist said, there was no known cause. He suggested two types of treatments: Botox injections, which can temporarily freeze the muscles; or antiseizure drugs or muscle relaxants, medications that can reduce spasms. He didn’t discuss surgery, which is often performed if a blood vessel is compressing the facial nerve.

The neurologist ordered an MRA, an MRI that focuses on blood vessels. Doctors said it, too, was normal. McInerny saw a second neurologist at the same clinic, who also suggested Botox and a muscle relaxer.

Drawn to alternative therapies, McInerny tried acupuncture instead. She also altered her diet, avoiding caffeine and dairy products, drinking celery juice, and taking a range of supplements.

At first, the approach seemed to be working. The spasms became less frequent and generally were not noticeable to others. McInerny joined two Facebook groups of people with hemifacial spasm, posting that others might want to try acupuncture since it seemed to be helping her.

For her next teeth cleaning, she found a new dentist, who rejected any tie between her spasms and the previous dental work. The dentist suggested McInerny see an ear, nose, and throat doctor. She did, and the ENT found nothing wrong, also ruling out a connection to the dental care.

In August 2023, after more than a year of regular acupuncture sessions, the jerky movements got worse. Actions, such as drinking, eating, or lifting weights, seemed to prompt them. McInerny increased the frequency of the acupuncture treatments, but the twitching only accelerated, even causing acupuncture needles to pop out of her face.

By November 2023, her eyes and mouth trembled even more frequently, and the shaking was evident to anyone who looked at her. One shopkeeper asked, “What’s wrong with your face?” McInerny started avoiding gatherings with friends, covering her face with her hands in public, and worrying that her 19-month-old grandson would be scared of her.

As someone who thrives on engaging people and looking them in the eye, she became depressed. “I’m a really extroverted person,” she said. “But I was withdrawing. It’s really hard when your personality is gone.”

She decided to contact the Mayo Clinic in Rochester, Minn., where many patients seek second opinions. The earliest she could get in was five months later, in April 2024.

A Mayo neurologist reviewed her brain scans from 2022 and repeated what the other neurologists had said: McInerny had hemifacial spasm, with no apparent cause, and should try Botox.

Finally, she did. In May 2024, another neurologist at Mayo injected her with small amounts of purified botulinum toxin in six locations around the right side of her face.

The treatment was a partial success, McInerny said. “It paralyzed the outward appearance of the contractions, but they were still happening,” she said. “Under the surface, you would still get the tremor.”

After several weeks, the benefit wore off. In July 2024, McInerny got an appointment with a different type of doctor at Mayo, a neurosurgeon. At her visit, Fredric Meyer called up a fresh MRI image he had ordered on a screen and pointed to what he said was causing her spasms: an artery compressing her facial nerve. It could be surgically repaired, he said.

McInerny couldn’t believe it. “I had been told, over and over, that I didn’t have any reason for this that could be fixed surgically,” she said.

Meyer recommended microvascular decompression, an operation in which surgeons open the skull behind the ear and lift the compressing blood vessel off the nerve, putting a material between the two structures to prevent contact. He explained that there were risks, including small chances of hearing loss and facial weakness.

In an interview, Meyer said he also looked at McInerny’s scans from 2022 and saw compression of the facial nerve on them. The other doctors apparently missed it, said Meyer, who performs more than 50 microvascular decompression surgeries a year, for hemifacial spasm and a similar but painful condition called trigeminal neuralgia.

“I just know where to look,” Meyer said. “Since this is a subspecialty expertise of mine, I’m going to be more focused on certain spots and more aware of what I’m looking for.”

Like McInerny’s other doctors, Meyer said he sees no link between her spasms and her dental work. The facial nerve is too deep for a dental anesthetic injection to harm it, so the timing of the onset of her symptoms likely was a coincidence, he said. Hemifacial spasm typically strikes in middle age, and women are twice as likely to develop it as men, according to the Cleveland Clinic.

“It’s probably just bad luck,” Meyer said. Aaron Cohen-Gadol, a neurosurgeon in Los Angeles who also does many microvascular decompression surgeries, agreed. He and Meyer said dental injections could injure the trigeminal nerve closer to the mouth, which might cause shooting pain, or neuralgia. But that’s separate from the facial nerve involved in hemifacial spasm, they said.

On Sept. 26, 2024, Meyer performed the four-hour surgery on McInerny, finding that a key artery supplying blood to part of her brain was pushing on her right facial nerve. He moved the artery off the nerve, placed dissolvable foam between the two and used surgical glue to attach the artery to the dura mater, or covering of the brain.

When McInerny woke up, her spasms were gone. More than a year later, they haven’t returned, and she is back to socializing like she did before. “The surgery gave me back my life and future,” she said.

She lost hearing in her right ear, however, which happens in about 8% of the surgeries, according to a multi-study review, because the hearing nerve is next to the facial nerve. Hearing sometimes returns weeks or months after surgery, but the loss is likely to be permanent if it has persisted for a year, Meyer said.

McInerny also gets dizzy and loses her balance sometimes, and some loud noises make it seem like “an air horn is going off” in her good ear, she said. But those shortcomings, while not trivial, pale in comparison to how the uncontrollable spasms ruled her life, she said.

“If my hearing loss is permanent, it was worth the price to relieve me from a lifetime of stress,” she said. “I’m incredibly thankful. I would do it again.”

David Wahlberg has been a medical reporter for 30 years, including at the Atlanta Journal-Constitution and the Wisconsin State Journal in Madison.