According to research, patients suffering from chronic primary insomnia have higher levels of brain activation compared to normal sleepers during a working memory test.

There are two types of insomnia, primary and secondary. Primary insomnia is sleeplessness that cannot be attributed to an existing medial, psychiatric or environmental cause (such as drug abuse or medications). Secondary insomnia is when symptoms of insomnia arise from a primary medical illness, mental disorders or other sleep disorders. It may also arise from the use, abuse or exposure to certain substances.

Results show that people suffering from primary insomnia use increased brain activation relative to good sleepers during the working memory task, particularly in areas responsible for visual-spatial attention and coordination of cognitive processes. This activation may explain how those with primary insomnia maintain performance on the task despite their sleep difficulties. Primary insomnia sufferers also were found to have decreased activation in visual and motor areas, which may suggest that subjects with primary insomnia have higher baseline activation in these regions relative to good sleepers.

According to principal investigator Henry Orff, these findings show that primary insomnia individuals, like those who are acutely sleep deprived, may be able to maintain performance on different tasks if they are able to compensate with increased brain activation.

"The good news is that patients with insomnia are probably able to function well in their daily lives and likely do not show significantly impaired performance," said Orff. "That said, patients may have to work, concentrate, and attend more to tasks than people who sleep well."

The study included 12 people with primary insomnia (six females) with an average age of 39.4 years, and nine good sleepers (four females) with an average age of 35.7 years.

Performance was compared between the two groups on a working memory task. Functional MRIs (FMRI) taken during the task were also compared. Behavioral performance was measured by reaction time for correct responses, number of correct responses, and number of errors committed.

The authors state that they do not know yet whether the findings suggest potential long-term implications for cognitive functioning in the future if primary insomnia is left untreated.
References:
1. Henry Orff, et al. Insomnia Patients Show Increased Cerebral Activation when Compared to Good Sleepers during an NBack Working Memory Task. American Academy of Sleep Medicine. Abstract ID: 0779.