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Cognigram Detects Cognitive Impairment In Schizophrenia Patients

April 10, 2014

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Patients diagnosed with schizophrenia have to battle not only the more well-known emotional symptoms of the mental disorder but often suffer from cognitive impairment including deficits in reaction time, attention, working memory and learning.  Even those who are already being treated with antipsychotic medication also need to have pharmacologic or behavioral therapies to control the cognitive side effects.  Assessing, measuring and monitoring these cognitive changes requires a quick, universal testing tool that patients can complete in a primary care setting.  In new research released this week, cognitive neuropsychologists report that Cognigram, a brief computerized set of tests developed by Cogstate, can detect cognitive decline in schizophrenia patients.

According to the NIMH, schizophrenia is a global health problem affecting over 51 million people, including:

  • 6 to 12 million people in China (a rough estimate based on the population)
  • 4.3 to 8.7 million people in India (a rough estimate based on the population)
  • 2.2 million people in USA
  • 285,000 people in Australia
  • Over 280,000 people in Canada
  • Over 250,000 diagnosed cases in Britain

Each year, more treatments are emerging to address schizophrenia’s devastating effects on emotional behavior including “positive” symptoms, such as delusions, hallucinations and disordered thinking, and “negative” symptoms of reduced motivation and engagement.

To address the associated cognitive deficits, clinicians require an assessment tool that can detect subtle changes in abilities over time but that doesn’t require hours of testing with highly trained specialists.  As has been reported previously here and here, the Cogstate Brief Battery (CBB) of tests has been shown to offer a very sensitive assessment of changes in executive function, learning, attention, motor control and working memory in schizophrenia patients.

Cognigram, a 15 minute, computerized version of the CBB for use by primary care physicians, is currently being used to track cognitive changes in older adults throughout Canada.

Cognigram in schizophrenia sensitivityIn a study presented this week at the Schizophrenia International Research Society Conference in Florence, Italy, neuroscientists from Cogstate along with Dr. Peter Snyder of Lifespan Hospital reported that Cognigram was able to detect and measure cognitive impairment in a large sample of schizophrenia patients.

Drawing from outpatient clinics in North America, Australia and the United Kingdom, the researchers recruited 471 schizophrenia patients to test their cognitive abilities using the CBB. All patients took two assessments less than one week apart, consisting of four tasks that are constructed around playing cards and are administered via computer.  On each trial a single playing card is presented and the participant must answer “yes” or “no” using a certain key on a computer keyboard.  The order in which the cards are presented and the rules used to guide decisions are summarized in this table:

Cogstate testRuleMain cognitive domain assessedPerformance measure
Detection testIs it there?Psycho-motor functionSpeed (msecs)
Identification testIs it red?AttentionSpeed (msecs)
One Back testIs it the same as previous?Working memorySpeed (msecs)
One Card Learning testHave you seen it before?LearningAccuracy (percent)

The results showed that 64% of the patients were classified with cognitive impairment, 26% were not and 10% were classified on one of the assessments.

“This study contributes to knowledge about the nature and frequency of cognitive impairment in people with chronic schizophrenia,” said Paul Maruff Ph.D., Chief Scientific Officer of Cogstate. “We have taken the approaches developed and validated in the Cognigram system and applied them to chronic schizophrenia.  Although we have been deliberately conservative in this application, we have observed that approximately 60% of people with chronic schizophrenia have cognitive impairment  when compared to healthy age matched controls. While this is early data it does provide a basis for further refinement of approaches and methods for identifying cognitive impairment in people with this debilitating illness.”

As has been shown with Alzheimer’s disease, depression, pediatric oncology and other brain disorders, Cognigram has proven to be a fast and reliable cognition testing system for physicians to incorporate in the daily care of their patients.

“What’s interesting about this approach for measuring cognitive impairment is that, compared with the two hours of testing by a skilled clinician, this approach takes less than 15 minutes and requires minimal expertise to administer,” said Judith Jaeger Ph.D., Vice President of Clinical Trials at Cogstate. “So it may be possible to look at changes within a patient and monitor their cognitive health in the same way we now monitor blood pressure. This could help us learn much more about the day to day fluctuations of cognition in patients with schizophrenia than was previously possible.”

Questions or comments? Please contact Dan Peterson