Brain injury news, Vol 3

Are you remembering correctly?  Don't count on it!

What do you remember about the events of September 11th?  If you're like most people, those memories are highly inaccurate. This is one disconcerting finding of numerous memory studies exploring how and what people recall. 

Memories, it seems, are far from factual.  Researchers expected "flashbulb" type memories of these traumatic events - sharp, accurate mental images of what happened.  Instead they got fictionalized accounts.  In people's memories, what happened is jumbled together with what they wished had happened, and what they learned later had happened.  

Perhaps most distressing is people's confidence in their memories.  Studies showed no correlation between confidence and accuracy.  In other words, people are very poor judges of what they do and do not remember.  

Forgetting things is bad enough...but even what we think we remember, we may not!

Adapted from a Wall Street Journal article 9/13/02

Motor neurons produced from embryonic stem cells

Researchers from the Howard Hughes Medical Institute have succeeded in getting cultured mouse embryonic stem cells to differentiate into functioning motor neurons.  Ultimately, the same type of approach might be used to grow human motor neurons from stem cells, thus enabling regeneration of nerve tissue lost to disease or trauma.

Reported in the journal Cell and published on-line July 17, 2002, these experiments used chemical signals to coax "naive neuroprogenitor" cells into differentiating into spinal cord motor neurons.  

Within the developing spinal cord, genes are being turned on and off rapidly, transforming immature cells into billions of specialized neural cells.  Harnessing this process could some day allow  the repair of diseased or damaged components of the mature central nervous system.

Survivors of mild brain injury benefit from receiving information booklet

Brain injury survivors given a booklet that outlines the symptoms associated with mild brain injury and suggests coping strategies will experience less anxiety and fewer on-going problems.  That's the conclusion of a recent study of 202 adults with mild head injuries. 

Participants assigned to an intervention group received an information booklet one week after injury.  Three months later, they reported fewer symptoms, better cognitive performance and psychological adjustment than brain injury survivors not receiving the booklet.

Reported in Journal of Neurology Neurosurgery and Psychiatry 2002; 73:330-332

"Slow down" to recover from mild brain injury

In the U.S. alone, more than $1.5 billion is spent annually to treat mild brain injury (MBI).  Such mild brain injuries often leave survivors incapacitated for months.  

A study reported in Research in Nursing & Health (Vol 25, Issue 4, 2002) found standard emergency room treatment for mild brain injuries to be inadequate.  

All participants demonstrated distractibility, impulsivity, irritability, and impaired executive functioning during the 24 hours after injury.  One in five continued to struggle with these issues throughout the 30-day study.  Loss of consciousness was associated with slower healing.

The report recommends that survivors of mild brain injury be given discharge directives to reduce cognitive demands for at least 48 hours - or 30+ days for those with loss of consciousness.

Depression: brain hemispheres out-of-sync?

Research suggests that illnesses such as depression may be associated with one half of the brain.  Activating the brain's other, healthier half, can improve the condition.  Activating the unhealthy hemisphere, on the other hand, can intensify problems.  So says a report in Neuropsychiatry, Neuropsychology, and Behavioral Neurology.

In healthy individuals, the two parts of the brain work together harmoniously.  However, it is thought that in people suffering from an illness like depression, one hemisphere may sabotage or dominate the other.  

To test this theory, Fredric Schiffer, associate attending psychiatrist at McLean Hospital, used a goggle test, directing stimuli to first one side of the brain, then the other,  to determine which hemisphere was healthy in each of 37 depressed patients.  Patients then underwent a two-week course of treatment to the left hemasphere, using electromagnetic fields.

Individuals identified through the goggle test as having healthy left hemispheres experienced a 42% reduction in depression symptoms, measured by the Hamilton Depression Rating Scale (HDRS).  As predicted, individuals identified through the goggle test as having healthy right hemispheres showed significantly less improvement (11%) with the left hemisphere treatment.