Posts tagged loss of consciousness
Articles and news from the latest research reports.
Fainting May Run in Families While Triggers May Not
New research suggests that fainting may be genetic and, in some families, only one gene may be responsible. However, a predisposition to certain triggers, such as emotional distress or the sight of blood, may not be inherited. The study is published in the April 16, 2013, print issue of Neurology®, the medical journal of the American Academy of Neurology. Fainting, also called vasovagal syncope, is a brief loss of consciousness when your body reacts to certain triggers. It affects at least one out of four people.
“Our study strengthens the evidence that fainting may be commonly genetic,” said study author Samuel F. Berkovic, MD, FRS, with the University of Melbourne in Victoria, Australia, and a member of the American Academy of Neurology. “Our hope is to uncover the mystery of this phenomenon so that we can recognize the risk or reduce the occurrence in people as fainting may be a safety issue.”
Researchers interviewed 44 families with a history of fainting and reviewed their medical records. Of those, six families had a large number of affected people, suggesting that a single gene was running through the family. The first family consisted of 30 affected people over three generations with an average fainting onset of eight to nine years. The other families were made up of four to 14 affected family members. Affected family members reported typical triggers, such as the sight of blood, injury, medical procedures, prolonged standing, pain and frightening thoughts. However, the triggers varied greatly within the families.
Genotyping of the largest family showed significant linkage to a specific region on chromosome 15, known as 15q26. Linkage to this region was excluded in two medium-sized families but not in the two smaller families.
(Image: Fotolia)
Prior Brain Injury Linked to Re-Injury Later in Life
Older adults with a history of traumatic brain injury (TBI) with loss of consciousness (LOC) have a 2.5- to almost four-fold higher risk of subsequent re-injury later in life, according to research published online Nov. 21 in the Journal of Neurology, Neurosurgery & Psychiatry.
Kristen Dams-O’Connor, PhD, of the Mount Sinai School of Medicine in New York City, and colleagues conducted a longitudinal, population-based, prospective cohort study enrolling 4,225 people aged >65 years who were dementia-free. The authors sought to determine whether there is a relationship between self-reported TBI with LOC and re-injury, dementia, and mortality later in life.
The researchers found that people who experienced a TBI with LOC before age 25 were 2.54-fold more likely to experience TBI with LOC during follow-up, while those injured after age 55 were 3.79-fold more likely. However, no association between TBI with LOC and dementia or Alzheimer’s disease was noted. Although baseline history of TBI with LOC was not associated with mortality, people who experienced a recent TBI had a 2.12-fold higher risk of mortality.
"This suggests that the risk for negative long-term outcomes (eg, dementia and premature mortality) may decrease with time since injury, such that individuals who survive to older adulthood and do not incur subsequent TBI may be at no greater risk for dementia or mortality than individuals who never sustained a TBI," the authors write. "Overall, the findings reported here underscore the need for effective strategies to prevent injury and re-injury in older adulthood."
(Source: empr.com)