Showing posts with label vestibular. Show all posts
Showing posts with label vestibular. Show all posts

Friday, January 24, 2014

Aspirin intake may stop growth of vestibular schwannomas/acoustic neuromas

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24-Jan-2014
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Contact: Mary Leach
Mary_Leach@meei.harvard.edu
617-573-4170
Massachusetts Eye and Ear Infirmary 

Aspirin intake may stop growth of vestibular schwannomas/acoustic neuromas

Findings described in the February issue of the journal Otology and Neurotology

BOSTON (Jan. 24, 2014) — Researchers from Massachusetts Eye and Ear, Harvard Medical School, Massachusetts Institute of Technology and Massachusetts General Hospital have demonstrated, for the first time, that aspirin intake correlates with halted growth of vestibular schwannomas (also known as acoustic neuromas), a sometimes lethal intracranial tumor that typically causes hearing loss and tinnitus.
Motivated by experiments in the Molecular Neurotology Laboratory at Mass. Eye and Ear involving human tumor specimens, the researchers performed a retrospective analysis of over 600 people diagnosed with vestibular schwannoma at Mass. Eye and Ear. Their research suggests the potential therapeutic role of aspirin in inhibiting tumor growth and motivates a clinical prospective study to assess efficacy of this well-tolerated anti-inflammatory medication in preventing growth of these intracranial tumors.
"Currently, there are no FDA-approved drug therapies to treat these tumors, which are the most common tumors of the cerebellopontine angle and the fourth most common intracranial tumors," explains Konstantina Stankovic, M.D., Ph.D., Mass. Eye and Ear clinican-researcher and assistant professor of otology andlaryngology, Harvard Medical School, who led the study. "Current options for management of growing vestibular schwannomas include surgery (via craniotomy) or radiation therapy, both of which are associated with potentially serious complications."
The findings, which are described in the February issue of the journal Otology and Neurotology, were based on a retrospective series of 689 people, 347 of whom were followed with multiple magnetic resonance imaging MRI scans (50.3%). The main outcome measures were patient use of aspirin and rate of vestibular schwannoma growth measured by changes in the largest tumor dimension as noted on serial MRIs. A significant inverse association was found among aspirin users and vestibular schwannoma growth (odds ratio: 0.50, 95 percent confidence interval: 0.29-0.85), which was not confounded by age or gender.
"Our results suggest a potential therapeutic role of aspirin in inhibiting vestibular schwannoma growth," said Dr. Stankovic, who is an otologic surgeon and researcher at Mass. Eye and Ear, Assistant Professor of Otology and Laryngology, Harvard Medical School (HMS), and member of the faculty of Harvard's Program in Speech and Hearing Bioscience and Technology.
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This work was funded by National Institute on Deafness and Other Communication Disorders grants T32 DC00038, K08DC010419 and by the Bertarelli Foundation. A full list of authors is available in the paper.
About Massachusetts Eye and Ear
Mass. Eye and Ear clinicians and scientists are driven by a mission to find cures for blindness, deafness and diseases of the head and neck. After uniting with Schepens Eye Research Institute Mass. Eye and Ear in Boston became the world's largest vision and hearing research center, offering hope and healing to patients everywhere through discovery and innovation. Mass. Eye and Ear is a Harvard Medical School teaching hospital and trains future medical leaders in ophthalmology and otolaryngology, through residency as well as clinical and research fellowships. Internationally acclaimed since its founding in 1824, Mass. Eye and Ear employs full-time, board-certified physicians who offer high-quality and affordable specialty care that ranges from the routine to the very complex. U.S. News & World Report's "Best Hospitals Survey" has consistently ranked the Mass. Eye and Ear Departments of Otolaryngology and Ophthalmology one of the top hospitals in the nation.


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Tuesday, October 8, 2013

Where does dizziness come from?

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[ Back to EurekAlert! ]Public release date: 8-Oct-2013
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Contact: Stephanie Desmon
sdesmon1@jhmi.edu
410-955-8665
Johns Hopkins Medicine 

Where does dizziness come from?

Johns Hopkins researchers pinpoint a key area for 'upright perception' in the human brain

Johns Hopkins researchers say they have pinpointed a site in a highly developed area of the human brain that plays an important role in the subconscious recognition of which way is straight up and which way is down.
The finding, described online in the journal Cerebral Cortex, may help account for some causes of spatial disorientation and dizziness, and offer targets for treating the feelings of unsteadiness and "floating" people experience when the brain fails to properly integrate input from the body's senses.
Disabling dizziness can be a symptom of damage to the inner ear or other senses such as vision. But in many cases, the problem instead appears to stem from a disruption of the processes in the brain that translate input coming from the inner ears about the pull of gravity and the eyes about our visual sensations into what is known as upright perception. The human brain has an automatic capacity to know which way is up even when our heads and bodies are askew. Studies of people in zero-gravity conditions suggest that sensing gravity plays a role in the perception of upright and spatial orientation.
"Our brain has this amazing way of knowing where we are in space, whether we are upright or tilted at an angle, even if it is completely dark and we can't see anything around us," says Amir Kheradmand, M.D., a neurology instructor at the Johns Hopkins University School of Medicine who conducted the research. "This study suggests there's a small area of neural tissue in the parietal cortex substantially involved in this ability, giving us a place to start thinking about how we may be able to treat people with disorienting dizziness."
Kheradmand says he and his team focused their attention on the right parietal cortex because studies in stroke victims with balance problems suggested that damage to that part of the brain was centrally involved in upright perception.
Recruiting eight healthy subjects for the study, the Johns Hopkins team placed each person individually in a dark room and showed them lines illuminated on a screen. The researchers instructed the subjects to report the orientation of the lines by rotating a dial to the right, left or straight.
The subjects then received what is known as TMS (trans-cranial magnetic stimulation), which painlessly and noninvasively delivers electromagnetic currents to precise locations in the brain that can temporarily disrupt the function of the targeted area. TMS is considered safe and is approved by the U.S. Food and Drug Administration to treat some patients with depression by stimulating nerve cells in the region of the brain involved in mood control and depression.
For this part of the experiments, each subject had an electromagnetic coil placed against the scalp in a 2-centimeter wide location across the right parietal lobe, behind the ear. This spot was found initially by mapping a small cortical region of the parietal lobe in one subject. At the identified location, the subjects got 600 electromagnetic pulses over the course of 40 seconds. After each 40-second session, the subjects were again asked to show researchers which way each illuminated line on the screen was oriented. The results wore off quickly and the subjects could again be tested on another day. Ultimately, the researchers found that each subject reported that his or her sense of being upright was skewed in the same way after TMS in the same spot in the parietal cortex: the supramarginal gyrus.
Kheradmand says the study's results raise the possibility that TMS could potentially be used to treat chronic dizziness. "If we can disrupt upright perception in healthy people using TMS, it might also be possible to use TMS to fix dysfunction in the same location in people with dizziness and spatial disorientation," he says.
"It's fascinating that we've gotten to the point that we can show that a subconscious perception can be altered using this simple, noninvasive technique," he adds. "We're excited that this could someday be a key to helping people who have dizziness and spatial disorientation to feel better." David S. Zee, M.D., and Adrian Lasker, M.S., both of Johns Hopkins, also contributed to this research.
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This work was supported by a training grant from the National Institutes of Health's National Institute on Deafness and Other Communication Disorders (2T32DC000023), and by the Leon Levy, Schwerin Family and Landenberger foundations.
Johns Hopkins Medicine (JHM), headquartered in Baltimore, Maryland, is a $6.7 billion integrated global health enterprise and one of the leading health care systems in the United States. JHM unites physicians and scientists of the Johns Hopkins University School of Medicine with the organizations, health professionals and facilities of The Johns Hopkins Hospital and Health System. JHM's vision, "Together, we will deliver the promise of medicine," is supported by its mission to improve the health of the community and the world by setting the standard of excellence in medical education, research and clinical care. Diverse and inclusive, JHM educates medical students, scientists, health care professionals and the public; conducts biomedical research; and provides patient-centered medicine to prevent, diagnose and treat human illness. JHM operates six academic and community hospitals, four suburban health care and surgery centers, and more than 30 primary health care outpatient sites. The Johns Hopkins Hospital, opened in 1889, was ranked number one in the nation for 21 years in a row by U.S. News & World Report.
Media Contacts:
Stephanie Desmon
410-955-8665; sdesmon1@jhmi.edu
Helen Jones
410-502-9422; hjones49@jhmi.edu


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