The 70-year-old woman hunched over her suitcase as she gingerly descended the front step of her condo. “Oh, my,” her neighbor said. “It looks like you’re having trouble walking. Are you OK?” The woman laughed. “I guess that’s just what happens when you turn 70,” she replied. She and her husband were on their way to Europe for a cruise through the Rhine Valley, and she was a little worried about the trip: She was having real trouble walking.
It started maybe six years earlier, when she noticed that it was somehow hard for her to stand still. It became intolerable at an awards ceremony, celebrating a friend’s success. Once the awarding was over and the schmoozing began, she realized she couldn’t bear to stand and chat. After a minute or two, she would get this overwhelming sensation that she had to either move or sit down. Around that time, she also noticed an ache deep in the muscles of her legs whenever she stood up. The only thing that made the pain go away was sitting or lying down.
Still, she never let it get in her way. Indeed, she and her husband had just gotten back from a trip to see their son in Southern California. They walked and hiked, and though she had to use her hiking sticks, she’d been fine. As the trip’s departure date approached, though, everything seemed to get worse. Walking was a real challenge. She had to put a hand on the wall or on a piece of furniture to keep her balance. It made her anxious, this unsteadiness. She worried that it could make this long-anticipated trip a lot less fun.
Her husband noticed, of course. He always managed to be right at her side whenever they left the house. But as they drove to the airport, all her fears came tumbling out. They had planned this trip for months — reading the history, learning about all the cities they would visit. How would she manage?
What the M.R.I.s Saw
She’d been to a half dozen doctors. First she saw an orthopedic surgeon. He had no idea why she couldn’t stand still. It wasn’t her joints — she had a good range of motion. And her muscles didn’t hurt when he squeezed them. An M.R.I. showed some spinal stenosis, spots in her lower back where the bony frame protecting the spinal cord had narrowed. But there was nothing he could operate on, he said.
A few years later, she tried again. This time she saw a neurologist. The symptoms didn’t ring any bells for her either. Nerve-conduction studies were unrevealing, and a new M.R.I. showed only more stenosis. A nerve block — a procedure in which numbing medicine was injected into her back — didn’t help at all.
On the cruise, the woman held on to her husband’s hand as they negotiated the ship and the streets of the towns they toured. People on the boat asked if they were newlyweds. The woman was forthright: No, she was having problems with balance and walking. That sparked sympathy and suggested diagnoses: Maybe it was Lyme disease; maybe it was a brain tumor. She thanked the concerned fellow travelers and tried not to dwell on the possibilities they suggested. The hardest part of the trip turned out to be the walking tours, because the guides walked so slowly. It was almost as bad as standing still. The couple would walk ahead, keeping the guide’s voice in their headphones. But by early afternoon, she would be worn out, as if she’d run a marathon. She needed a wheelchair to negotiate the airport on their trip home.
A few weeks later, she was finally able to see a neurosurgeon. The only abnormality anyone found, she told him, was the spinal stenosis. Could surgery give her back the mobility and balance she’d lost? The neurosurgeon was direct: He wasn’t sure what was wrong with her legs, but he was confident the spinal stenosis wasn’t part of it. By her age, most people had scans as bad or worse than hers and had no problems. He referred her to yet another neurologist, who recognized that she had some kind of movement disorder and referred her to Dr. Thomas Tropea, a neurologist who specialized in this type of disease.
A Telltale Flit-Flit-Flit
Tropea had only recently finished his training to join the faculty at the University of Pennsylvania’s Perelman School of Medicine. To the patient and her husband, he looked incredibly young. But as soon as the woman began describing her symptoms — the pain and instability when she stood up that was completely absent when she was off her feet and the constant need to walk, once upright — Tropea looked intrigued. Can you stand up? he asked. She stood and steadied herself against the exam table. Can you walk around the exam room? Happily: The pain and unsteadiness she felt while standing completely resolved with motion.
Then he asked her if she could squat. As the woman lowered herself just a couple of inches from her standing height, the ache and unsteadiness again disappeared, the way it had when she was walking. The young doctor had her stand up straight, then knelt next to her. She watched as he took out his stethoscope and laid it gently against the back of her knees. Through the earpieces he heard a flit-flit-flit, almost like a helicopter’s rotors. Tropea nodded. He knew what this was.
She had, he explained, a rare disorder called orthostatic tremor (O.T.). The woman was amazed and confused: A tremor? She felt unsteady, and she certainly felt achy, but she didn’t feel as if any part of her was shaking. The muscle fibers in her leg, the doctor explained, weren’t shaking so much as vibrating. When tested, the muscle fibers in people with this disorder flutter at a rate up to 18 beats a second. The fibers don’t move far, just very, very fast. And it only happens while standing.
Tremors are often divided into categories. There are tremors that cause movement when the muscles are at rest — patients with Parkinson’s disease often have this type. Then there are what are called intention tremors, when the involuntary movement appears as a patient tries to complete an action such as reaching for a glass. This tremor is usually slow, the movement large. It is often seen in patients with multiple sclerosis. And then there are postural tremors. Triggered by resistance to gravity, this is the most common type. Just holding a hand out from the body can trigger a postural tremor in those with what’s known as an essential tremor — the tremor most often seen in those over 65. But orthostatic tremor is in a class by itself: a high-frequency tremor that primarily affects the legs and trunk, triggered by standing and relieved with movement.
The woman was full of questions. Where did this tremor come from? Will it get worse? Can it be treated? Tropea shook his head. There’s a lot we don’t know about this tremor, he told her. It was only recognized 40 years ago and has often been overlooked because many patients, like her, do not have a visible tremor — at least not initially. And yes, it often gets worse over time. But there are treatments that can make it better, though nothing can cure it or keep it from progressing. Like other types of tremor, O.T. usually responds to a class of medication called benzodiazepines, which are often used in the treatment of anxiety disorders. They work by increasing the effectiveness of the inhibitory chemical in the brain called GABA. No one knows what causes O.T. What we do know is that it’s rare; it’s most commonly found in women; and it usually starts around 60.
The patient began taking the medication, slowly increasing it to the most effective dose. And it was wonderful. She could stand — though still not for as long as she used to. And she could walk; she could even stroll. The ache in her legs never totally went away, but it eased up. She got her diagnosis four years ago. Since then, as predicted, the medication has become less effective and her sense of instability more profound. These days, she has to use a walker. It was embarrassing at first, but she refuses to let it slow her down. She is a percussionist in a local concert band. And she hits the pool twice a week. She might need the walker for stability, but she’s still strong, and she’s hopeful that a new medication Tropea just started her on will help her stay that way.
Lisa Sanders, M.D., is a contributing writer for the magazine. Her latest book is “Diagnosis: Solving the Most Baffling Medical Mysteries.” If you have a solved case to share, write her at Lisa.Sandersmdnyt@gmail.com.