Impairments in Brain Involved in Post Stroke Depression (PSD)

Thirty to fifty percent of people who survive a stroke, experience depression. Depression can either be major or minor and sets in after some time after the attack. But depression may also set in some months or even a year after the stroke occurred.

Major depression occurs in about 20 percent of patients. It is the most severe form of clinical depression.

Post stroke depression (PSD) is the most common neuropsychiatric consequence of a stroke. It is categorized by the The Diagnostic and Statistical Manual of Mental Disorders (DSM) IV as a “mood disorder due to a general medical condition (i.e. stroke)" with the specifiers of depressive features, major depressive-like episodes, manic features, or mixed features.

The DSM published by the American Psychiatric Association (AMA) provides a common language and standard criteria for the classification of mental disorders.

Symptoms of Post Stroke Depression are:

Persistent sad, anxious or “empty” mood
Feelings of hopelessness, pessimism
Feelings of guilt, worthlessness, helplessness
Loss of interest or pleasure in hobbies and activities that were once enjoyed, including physical intimacy
Decreased energy, fatigue, being “slowed down”
Cognitive problems; difficulty concentrating, remembering, making decisions
Insomnia, early-morning awakening, or oversleeping
Loss of appetite, weight changes
Suicidal thoughts, or suicide attempts
Restlessness and irritability

Post-stroke depression linked to 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. Results of the study are published online in the journal Radiology.

"A third of patients surviving a stroke experience post-stroke depression (PSD)," said lead researcher Igor Sibon, M.D., Ph.D., professor of neurology at the University of Bordeaux in Bordeaux, France. "However, studies have failed to identify a link between lesions in the brain caused by ischemia during a stroke and subsequent depression."

Video: Tackling Depression After A Stroke

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 said. "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."

In the study, 24 patients between the ages of 18 and 80 underwent resting-state functional magnetic resonance imaging (fMRI) 10 days after having mild to moderate ischemic stroke. An fMRI imaging study measures metabolic changes in specific areas of the brain. Although many fMRI exams are designed to measure brain changes while a patient performs a specific task, during a resting-state fMRI exam, patients lie motionless.

The patients, which included 19 men and five women, were also clinically evaluated 10 days and three months post-stroke to determine the presence and severity of depression and anxiety symptoms. At three months post-stroke, patients were evaluated for depression using the DSM-IV diagnostic classification system.

Using the DSM-IV criteria, 10 patients had minor to moderate depression, and 14 patients had no depression. Results of the fMRI exams revealed an association between modifications of connectivity in the DMN 10 days after stroke and the severity of depression three months post-stroke.

"We found a strong association between early resting-state network modifications and the risk of post-stroke mood disorders," Dr. Sibon said. "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 fMRI results immediately post-stroke indicate impaired connectivity in the DMN.

Quantum Day

05 June 2012

Impairments in Brain Involved in Post Stroke Depression (PSD)