A rare disease made a woman faint every time she sat up or stood up. Now, with a new device implanted in her spinal cord, she can stand with a walker and walk the length of two and a half football fields.
Researchers recently used the same implanted device to treat three men with debilitating spinal cord injuries. Live Science previously reported. In these patients, the implant stimulated certain nerves in the spinal cord, which then activated muscles in the trunk and legs. This allowed the men to stand, walk, and even cycle on a stationary bike.
In women, the implant instead stimulates spinal nerves, which when activated narrow arteries in the trunk and legs. Normally, when a woman sits up or sits up, her blood pressure drops, and this often leads to fainting spells due to insufficient blood flow and oxygen supply to the brain. By telling the arteries in the lower body to narrow, the spinal implant prevents this drastic drop in blood pressure, thus preventing her from losing consciousness.
Prior to the implantation, the patient “fainted many times each day…every time she went to the bathroom, she would faint,” said Dr. Jocelyne Bloch, a neurosurgeon at Lausanne University Hospital and associate professor at the University of Lausanne in Switzerland, who treated the woman and co-authored the report on her case. “It was striking … to see her standing vertically and not immediately fainting and then walking” after the implant was placed, Bloch told Live Science.
Researchers released a report Wednesday (April 6) detailing the woman’s case The New England Journal of Medicine (opens in new tab).
Based on her assessments of the patient, “These are undoubtedly clinically relevant benefits,” said Dr. Jose-Alberto Palma, a research associate professor of neurology at New York University Grossman School of Medicine who was not involved in the woman’s case.
However, the results “must be interpreted with extreme caution, since [this] was an isolated case, without any kind of blinding or control group, so there is a high possibility of bias,” Palma told Live Science in an email. It’s also important to note that while the implant has improved the patient’s quality of life, it doesn’t address their underlying neurodegenerative disease, which is fatal, he said.
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The woman’s blood pressure problem, known as orthostatic hypotension, occurred as a result of a relatively rare neurodegenerative disease called multiple system atrophy (MSA). The progressive disease causes nerve cells in the brain and spinal cord to fail and eventually die, and it also causes abnormal clumps of protein to appear in certain brain cells, according to the National Institute of Neurological Disorders and Stroke (opens in new tab).
MSA affects the part of nervous system which controls involuntary bodily functions such as blood pressure and bladder control, and also damages key areas of the brain involved in motor control and coordination.
“Orthostatic hypotension affects approximately 80% of patients with MSA and is a cardinal feature of the disease,” said Palma. Medications, including those that constrict blood vessels or trigger water and salt retention, can help relieve symptoms, he noted, but in this patient’s case, medications failed to stop the fainting spells.
Prior to the insertion of the new implant, the patient felt dizzy constantly whenever she tried to stand up and would faint about 3-4 times a day. After a fainting spell that occurred within seconds of getting up, the patient became bedridden and remained so for about 18 months.
Normally, when blood pressure falls, sensory cells in the heart detect the change and send a message to the brain, Bloch said. The brain then sends signals through the nerves in the spinal cord to constrict the arteries and make the heart beat faster, causing blood pressure to spike again. However, in the patient, this feedback loop—called the baroreflex—was disrupted, she said.
Bloch and her colleagues had previously repairs this feedback loop (opens in new tab) in people with debilitating spinal cord injuries, so they thought the same treatment might work in MSA patients.
The implant includes a device that generates electrical impulses and has an embedded accelerometer that detects changes in the patient’s body position. This pulse generator is then connected to a soft, paddle-shaped lead that carries 16 electrodes that transmit the pulses to nerves in the spinal cord.
The patient underwent surgery to place the pulse generator in her abdomen and the electrode-carrying paddle directly on the nerves in her thoracic spine beneath the vertebrae. Such a procedure carries some risk of infection and spinal cord injury, Bloch noted. Once implanted, the device can be turned on or off outside the body using software operated on a tablet.
Promising results
After the procedure, the patient underwent tilt-table tests for seven days, during which her doctors monitored her blood pressure while moving her from a horizontal to a vertical position. The device prevented the patient’s usual dizziness and drop in blood pressure.
The woman also completed six weeks of neurorehabilitation in the hospital and was allowed to practice using the device at home after three weeks. After exercising, she no longer passed out or had the symptoms that preceded these seizures, such as ringing in the ears and dizziness when standing or urinating.
Before the procedure, the patient could only walk about 5 meters before having to lie down. Within a few weeks of receiving the implant, she was able to walk about 10 times that distance with a walker, and after three months she was able to walk about 50 times that distance. After eight months, “the patient reported that she was still being stimulated throughout the day and no longer had syncope [loss of consciousness]’ the researchers report.
“She could exercise, run, go from bed to bathroom at home without fainting… We clearly saw a difference,” Bloch said.
The new implant does not address the patient’s underlying disease; Over the weeks, the various symptoms of her MSA-P have also developed. “The surgery… will do nothing to halt the rapid progression of the disease,” Palma said. Patients with MSA typically need to use a wheelchair within three to four years of onset and die within five to eight years, he said.
“We know we’re not going to stop the disease,” Bloch said. “But… at least that symptom is still okay. It’s not perfect, but it’s much better than before the treatment.”
Bloch said she expects to identify other diseases where such a spinal implant could improve patients’ mobility and quality of life.
Meanwhile, Bloch and her co-senior author Grégoire Courtine, a professor of neuroscience at the Swiss Federal Institute of Technology in Lausanne (EPFL), are collaborating with a company called Onward Medical to develop new spinal implants specifically designed to treat patients with disabilities became mobility or problems with blood pressure regulation. The first of these newly developed devices will be implanted later this year, likely in May, Bloch said.
Originally published on Live Science.