June 6, 2012
Post-Stroke Depression Linked to Functional Brain Impairment
(Ivanhoe Newswire) - Every 45 seconds, someone suffers a stoke. They not only cause physical impairments, but also brain impairments. In fact, new research has linked post-stroke depression to a functional brain impairment.
Researchers studying stroke patients have found a strong association between impairments in a network of the brain involved in emotional regulation and the severity of post-stroke depression.Lead researcher Igor Sibon, M.D., Ph.D., professor of neurology at the University of Bordeaux in Bordeaux, France was quoted as saying, "A third of patients surviving a stroke experience post-stroke depression (PSD)," however, studies have failed to identify a link between lesions in the brain caused by ischemia during a stroke and subsequent depression."
Instead of looking for dysfunction in a specific area of the brain following a stroke, Dr. Sibon's study was designed to assess a group of brain structures organized in a functional network called the default-mode network (DMN). Modifications of connectivity in the DMN, which is associated with internally generated thought processes, has been observed in depressive patients.
"The default-mode network is activated when the brain is at rest," Dr. Sibon was quoted as saying. "When the brain is not actively involved in a task, this area of the brain is engaged in internal thoughts involving self-related memory retrieval and processing."
24 patients which included 19 men and 5 women underwent brain observations for 10 days after suffering from a mild to moderate stroke. They were also clinically evaluated for 10 days and three months post-stroke for depression.
The results showed that 10 out of the 24 patients had minor to moderate depression, and the remaining 14 patients, had no depression.
Dr. Sibon was quoted as saying, "We found a strong association between early resting-state network modifications and the risk of post-stroke mood disorders," these results support the theory that functional brain impairment following a stroke may be more critical than structural lesions."
According to Dr. Sibon, the widespread chemical changes that result from a stroke may lead to the modification of connectivity in brain networks such as the DMN. He said results of his study may contribute to the clinical management of stroke patients by providing an opportunity to investigate the effects of a variety of treatments on patients whose results immediately post-stroke indicate impaired connectivity in the DMN.