"We're finding that some portion of cognitive impairment usually blamed solely on the disease of schizophrenia might actually be a combination of schizophrenia and prior exposure to herpes simplex virus 1 infection, which reproduces in the brain," says study leader David J. Schretlen, Ph.D., an associate professor in the Department of Psychiatry at Johns Hopkins University School of Medicine.
The research, described in the May Schizophrenia Research, could lead to new ways to treat or prevent the cognitive impairment that typically accompanies this mental illness, including with antiviral drugs, the scientists say.
Doctors have long known that cognitive impairment, including problems with psychomotor speed, concentration, learning, and memory, are prevalent features of schizophrenia, which affects an estimated one percent of the U.S. population. Cognitive deficits often surface months to years before symptoms that are traditionally used to diagnose this disease, such as delusions or hallucinations.
Some previous studies have shown that schizophrenic patients with antibodies to herpes simplex virus 1 (HSV-1), the virus that causes cold sores, often have more severe cognitive deficits than patients without these antibodies. Other studies have shown that patients with HSV-1 antibodies have decreased brain volumes compared to patients without the antibodies. However, it has been unclear whether the cognitive deficits are directly related to the decreased brain volume.
To investigate, Schretlen and his colleagues recruited 40 schizophrenic patients from outpatient clinics at the Johns Hopkins and Sheppard Enoch Pratt hospitals in Baltimore, Md. Blood tests showed that 25 of the patients had antibodies for HSV-1 and 15 didn't. The researchers gave all of the patients tests to measure speed of coordination, organizational skills and verbal memory. The patients then underwent MRI brain scans to measure the volume of particular regions of their brains.
As in previous studies, results showed that patients with antibodies to HSV-1 performed significantly worse on the cognitive tests than patients without the antibodies. But expanding on those earlier studies, analysis of the brain scans showed that the same patients who performed poorly on the tests also had reduced brain volume in the anterior cingulate, which controls processing speed and the ability to switch tasks. There was also shrinkage in the cerebellum, which controls motor function.
These results suggest that HSV-1 might be directly causing the cognitive deficits by attacking these brain regions, Schretlen says.
Though the researchers aren't sure why schizophrenia might make brains more vulnerable to a viral assault, Schretlen says the results already suggest new ways of treating the disorder. Data from other studies has shown that antiviral medications can reduce psychiatric symptoms in some patients with schizophrenia. "If we can identify schizophrenic patients with HSV-1 antibodies early on, it might be possible to reduce the risk or the extent of cognitive deficits," he adds.
Other Johns Hopkins researchers who participated in this study include Tracy D. Vannorsdall, Ph.D., Jessica M. Winicki, B.A., Takatoshi Hikida, M.D., Akira Sawa, M.D., Ph.D., Robert H. Yolken, M.D., and Nicola G. Cascella, M.D.For more information, go to:
Christen Brownlee | EurekAlert!
Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Materials Sciences
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy