Neurologists have been misdiagnosing dozens of patients experiencing sudden visual loss in one eye (also called monocular vision loss) with multiple sclerosis (MS). Although the symptoms of monocular vision loss are very real, doctors are now discovering that they are not always related to MS. The main culprit behind the uptick in monocular vision loss cases is increased smartphone use.
Instead of MS, most of the patients reporting temporary blindness suffered from a phenomenon known as transient smartphone blindness (TSB). People who experience TSB often report symptoms of painless monocular vision loss, especially after looking at their smartphone in bed for a few minutes.
One new case of mistaken MS/TSB diagnosis was reported in a recent issue of the journal Neurology. This January 18th report discussed a middle-aged woman who had symptoms of painless monocular vision loss.
The female patient told doctors that she experienced blindness in her right eye for 15 seconds after getting up from her bed in the morning. She said she was looking at her smartphone while lying on her left side 15 minutes prior to getting out of bed. Besides the smartphone, there were no other lights on in the patient's bedroom.
The patient recovered her full sight within about a minute. Although the experience was uncomfortable, the patient said she experienced no ocular pain.
Besides temporary blindness, this woman presented no other symptoms of MS. The patient went through rigorous screenings, including cardiovascular tests and an MRI scan. The only thing somewhat abnormal about this woman's health was the appearance of bilateral cerebral white matter lesions on her brain MRI. However, her cervical and spine MRIs were healthy, and she showed no signs of health issues for her age.
Despite all of this evidence to the contrary, the neurologist diagnosed the patient with MS.
After six months of treatment for MS, the patient went back to her neurologist for a follow-up MRI scan. This scan showed no changes from the previous session. Only after reviewing this data did the neurologist change her diagnosis from MS to TSB, claiming that the white matter lesions on the patient's brain were more likely "small vessel cerebrovascular disease" rather than symptoms of MS.
This isn't the first time the misdiagnosis of MS for TSB has appeared in a major medical publication. Two cases in the U.K. published in the New England Journal of Medicine detailed how two women with frequent monocular vision complaints were misdiagnosed with MS. Only later did doctors realize these female patients were just suffering from TSB.
Specialists at Mayo Clinic looking into these case histories warn doctors from being overhasty in diagnosing MS. Since smartphones are more diffuse in our population, TSB cases will become more common as the years progress.
Dean M. Wingerchuck of Mayo Clinic wrote that doctors thinking of diagnosing a patient with MS should be sure they aren't misinterpreting nonspecific brain abnormalities in the patient's MRI scan. Dr. Wingerchuck went on to say that all MS patients must show evidence of central nervous system demyelination, and they must typically have evidence of one MS attack.
MS is an autoimmune disorder that damages the body's nerves. A few symptoms of MS include fatigue, balance problems, temporary blindness, slurred speech, extreme mood swings, and digestive issues. There are around 200,000 new cases of MS annually in the USA. Traditional treatments for MS include physical therapy, counseling, immunosuppressive drugs, dietary changes, and acupuncture.